This thesis examines if the correlations between equity sectors have increased over time, mitigating sector diversification. Investors and other financial enthusiasts have started to believe that sector diversification is not a useful investment strategy. To investigate whether correlations among the sectors are rising, this study analyzes numerous aspects regarding sector diversification. Twenty years of monthly sector returns are used to determine whether correlations among the sectors are increasing. Also, the analyzation of sector movement during up and down periods of the market is addressed within the thesis. This study finds that the majority of the sectors move together in times of a financial crisis, like the 2007-2008 market crash. Thus, when sector diversification is most needed, it often fails during times of strife. Furthermore, the study analyzes how the majority of the sectors tend to not move with the market over the twenty-year period. Results suggest the correlations between the sectors have not become closer contrary to popular belief. The importance and usefulness of sector diversification when investing is validated by this study’s results.

Comme de nombreux autres oxydes de métaux de transition lamellaires, les cobaltates dopés au sodium, NaxCoO2, présentent un riche diagramme de phase. Les nombreuses instabilités (magnétiques, de charge) qui les caractérisent seraient notamment le fruit des corrélations électroniques. Dans cette thèse, nous nous intéressons au cas fortement dopé x=2/3 (proche de la limite de l'isolant de bande). Expérimentalement, ce composé est sujet à une disproportion de charge locale sur les atomes de cobalt, ce qui en fait un terrain d'étude privilégié pour le calcul des fonctions de corrélation de charge. Le traitement théorique de ce système est difficile a bien des égards. D'abord, la corrélation électronique demande de recourir à des approximations avancées. Ensuite, le système est sensible aux détails microscopiques, tels que transcrits dans la structure électronique réelle. Dans cette thèse, nous abordons ces deux aspects, à travers un approche sur modèle et une approche ab initio.Nous examinons d'abord l'effet des corrélations au niveau d'un modèle sur réseau triangulaire, pertinent pour les cobaltates. La compétition entre les interactions de Coulomb locale et non-locale sur un modèle de Hubbard étendu donne lieu à des fluctuations de charge, que nous traitons grâce à la théorie du champ moyen dynamique étendue. Nous dressons le diagramme de phase de notre modèle en fonction des interactions locales et non-locales. Celui-ci présente une transition du second ordre entre un état métallique homogène et une phase ordonnée de charge. Nous calculons les observables à une et deux particules dans la phase homogène, et nous déterminons l'effet des corrélations sur ces deux types d'observables. Nous interprétons ces résultats comme des conséquences du fort dopage. Nous identifions une région du diagramme de phase où la partie statique de l'interaction de Coulomb écrantée devient négative. Enfin, nous montrons comment incorporer un terme de Fock non-local à ces calculs, et nous détaillons son effet sur le diagramme de phase et sur les observables physiques.En complément de notre approche sur modèle, nous étudions les détails microscopiques du matériau réel grâce à la théorie de la fonctionnelle de la densité. Nous analysons le rôle de l'hybridation avec l’oxygène et des processus de saut électronique sur la structure de bandes pour les plans de cobalt-oxygène. Nous clarifions l'effet de certains paramètres physiques, tels que le dopage au sodium, l'arrangement cristallin ou le magnétisme, sur la structure électronique. Puis nous calculons la susceptibilité de charge selon les premiers principes, selon des approximations suggérées par notre étude de modèle sur réseau.La comparaison entre les calculs sur modèle et ab initio montre que ces approches se complètent l'une l'autre. D'une part, le modèle permet de dégager les approximations pertinentes pour le calcul des fonctions de corrélation de charge. D'autre part, les calculs ab initio et la compréhension des processus microscopiques sont le préalable à la construction d'un modèle réaliste et prédictif. / As many other layered transition-metal oxides, sodium-doped cobaltates, NaxCoO2, present a rich phase diagram. They display numerous instabilities (magnetic, charge-order), originating most likely from electronic correlations. In this thesis, we focus on the case x=2/3, in the strong-doping limit (close to the band-insulating limit). An experimentally-observed charge disproportionation on the cobalt atoms makes this particular composition an interesting playground to study charge-correlation functions. The theoretical treatment of this system is difficult in several aspects. In order to capture electronic correlations, one needs to resort to advanced non-perturbative approaches. Also, the system is sensitive to its microscopic details, as encoded in the real electronic structure. This is why, in this thesis, we adopt model as well as ab initio approaches to address both these issues.We first study the effect of correlations at the model level, on a triangular lattice, specifically designed for the cobaltates. The interplay between local and non-local Coulomb interactions gives rise to charge fluctuations, which we capture using the Extended Dynamical Mean-Field Theory. We establish the phase diagram of our model as a function of local and non-local interactions. It displays a second-order phase transition between a homogeneous metallic phase, and a charge-ordered phase. We compute one and two-particle observables in the homogeneous phase, and we analyse how they are influenced by correlations. We show that our findings can be understood as a consequence of the strong doping. We find a region of the phase diagram where the static screened Coulomb interaction becomes negative. Finally, we show how to incorporate a non-local Fock term in the calculation of the self-energy, and how it influences the phase diagram and the physical observables.Next, in order to complement the model approach, we study the microscopic details of the real sodium-cobaltates by using Density-Functional Theory. We analyse the effect of oxygen hybridisation and electronic hopping processes on the band structure of cobalt-oxygen planes. We study the effects of sodium doping, crystal structure and magnetism, on the band structure of this material. Then, we compute the charge susceptibility from first principles in the independent-particle approximation and in the random-phase approximation. We use the insight gained from the model calculation to discuss these results.The comparison between the model and the ab initio calculations shows that these approaches are complementary. The model enables us to define the best approximations for the calculation of charge correlation functions. The ab initio calculations, and the detailed understanding of microscopic electronic processes are the prerequisite for a model that is both realistic and predictive.

Synthetic biology is an emerging field that integrates and applies engineering design methods to biological systems. Its aim is to make biology an "engineerable" science. Over the years, biologists and engineers alike have abstracted biological systems into functional models that behave similarly to electric circuits, thus the creation of the subfield of genetic circuits. Mathematical models have been devised to simulate the behavior of genetic circuits in silico. Most models can be classified into deterministic and stochastic models. The work in this dissertation is for stochastic models. Although ordinary differential equation (ODE) models are generally amenable to simu- late genetic circuits, they wrongly assume that a system's chemical species vary continuously and deterministically, thus making erroneous predictions when applied to highly stochastic systems. Stochastic methods have been created to take into account the variability, un- predictability, and discrete nature of molecular populations. The most popular stochastic method is the stochastic simulation algorithm (SSA). These methods provide a single path of the overall pool of possible system's behavior. A common practice is to take several inde- pendent SSA simulations and take the average of the aggregate. This approach can perform iv well in low noise systems. However, it produces incorrect results when applied to networks that can take multiple modes or that are highly stochastic. Incremental SSA or iSSA is a set of algorithms that have been created to obtain ag- gregate information from multiple SSA runs. The marginal probability density evolution (MPDE) algorithm is a subset of iSSA which seeks to reveal the most likely "qualitative" behavior of a genetic circuit by providing a marginal probability function or statistical enve- lope for every species in the system, under the appropriate conditions. MPDE assumes that species are statistically independent given the rest of the system. This assumption is satisfied by some systems. However, most of the interesting biological systems, both synthetic and in nature, have correlated species forming conservation laws. Species correlation imposes con- straints in the system that are broken by MPDE. This work seeks to devise a mathematical method and algorithm to correct conservation constraints errors in MPDE. Furthermore, it aims to identify these constraints a priori and efficiently deliver a trustworthy result faithful to the true behavior of the system.

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第17967号 / 情博第511号 / 新制||情||91(附属図書館) / 30797 / 京都大学大学院情報学研究科知能情報学専攻 / (主査)教授 松山 隆司, 教授 乾 敏郎, 教授 石井 信 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

<p>The top quark is the most massive known elementary particle, and plays a pivotal role in our understanding of particle physics. Its unique properties offer valuable insights into the Standard Model and potential hints for physics beyond the Standard Model. In this thesis we present a precision measurement of the polarization of top quarks and spin correlations between top-antitop (ttbar) pairs using Run-II datasets collected from the Compact </p> <p>Muon Solenoid detector at the Large Hadron Collider. In the first part of this thesis we introduce the theoretical framework of the Standard Model and its predictions regarding top quark spin polarization and ttbar spin correlations. Next, we describe the experimental setup, reconstruction techniques, and Monte Carlo simulations used in this research. Subsequently, details of the measurement, including event selection, top quark reconstruction, and unfolding are described. The analysis achieves exceptional signal purity and precision with respect to previous measurements. The measured values of coefficients are in agreement with Standard Model expected values as well as theoretical predictions at NLO in QCD. In a first, we provide provide double-differential cross sections of top quark spin polarizations and ttbar spin correlations, as a function of the invariant mass of the ttbar system. We expect the results from the final CMS publication to supersede any results presented in the measurement part of this thesis document. In the final section of this thesis, we present a projection study of top quark spin polarization and tt ̄ spin correlations at the upcoming High Luminosity LHC. We present projections of the fraction of SM-like events and show that the upcoming detector could reduce uncertainties by as much as a factor 2. An alternative to the SM scenario is also considered in the form of Super Symmetry, and it is shown that we can significantly increase the ultimate reach of the LHC to discover top squarks in the degenerate mass corridor in the top squark-neutralino plane, or in the absence of a discovery exclude top squarks up to 600 GeV. </p>

Correlations and entanglement in a chain of three oscillators A,B,C with nearest neighbour coupling is studied. Oscillators A,B and B,C are coupled but there is no direct coupling between oscillators A,C. Examples with initial factorizable states are considered, and the time evolution is calculated. It is shown that the dynamics of the tri-partite system creates correlations and entanglement among the three oscillators and in particular, between oscillators A,C which are not coupled directly. We have performed photon number selective and non-selective measurements on oscillator A and we investigated their effects on the correlations and entanglement. It is shown that, before the measurement, the correlations between oscillators A,C can be stronger than the correlations of oscillators A,B. Moreover, some entanglement witness shows that oscillators A,C are entangled but the oscillators A,B might or might not be entangled. By using quantum discord, which measures the quantumness of correlations, it is shown that there are quantum correlations between oscillators A,B and after the measurements in both cases of selective and non-selective measurements, oscillators A,B and A,C become classically correlated. / Ministry of Higher Education, Malaysia and Universiti Kebangsaan, Malaysia.

<p> Using the technique of perturbed angular correlations, the rotation of the 4 + 366 keV 152Sm level and the rotation of the 2 + 344 keV 152Gd level was observed. These nuclei were the daughter nuclei of 152Eu, present in the europium - gadolinium and europium - holmium alloys which were commercially obtained (europium concentration was about 1% in both alloys). Anomolously low fields were obtained for 152Gd in gadolinium and in the holmium which raised doubts as to the homogeneity of the alloys.</p> <p> Samples of the alloys were analysed metallurgically. After chemical treatment and microscopic examination the presence of inclusions was detected. Electron microprobe examinations indicated that the inclusions were europium. The metallurgical analysis confirmed the doubts raised by the nuclear experiments showing that the two methods can be employed complementarily for alloy analysis.</p> / Thesis / Master of Science (MSc)

AN ABSTRACT OF THE DISSERTATION OFKaleigh C. Best, for the Doctor of Philosophy degree in Anthropology, presented on May 12, 2023, at Southern Illinois University Carbondale. TITLE: AN INVESTIGATION INTO INTRAINDIVIDUAL VARIATION IN HUMAN SKELETAL SEXUAL TRAIT MORPHOLOGYMAJOR PROFESSOR: Dr. Izumi ShimadaSex estimation is the most vital component of the biological profile assessment as several other subsequent analyses across biological anthropology rely on the correct identification of biological sex. This is especially important in times of commingling, fragmentary and partial remains, in inconsistent sex estimation, or in studies of sex estimation variation. While a multitude of studies have contributed to the documentation of similarities and differences in the morphological expression of a specific trait and how well this trait can be used to classify the sex of an unknown individual, how the expression of these morphological traits relate to each other within the individual has been poorly studied. Further, although several intrinsic and extrinsic factors are known to contribute to sexual trait expression, how they interact to produce morphology, and how that morphology may change in response to different biological conditions is not well understood. This dissertation utilizes 3D scans of 235 individuals collected from the University of Tennessee Donated Skeletal Collection (UTK) and the Robert J. Terry Osteological Collection (Terry) to examine sexual trait expression across the cranium, mandible, os coxae, sacrum and scapula. Specifically, it evaluates: 1) if sexual trait expression is correlated between skeletal regions including localized anatomical regions, through matrix correlation and Pearson correlation tests, 2) if age affects morphological sexual trait expression through M/ANOVA and if so, how and when these changes occur using ANOVA and Tukey post-hoc tests, 3) if the magnitude and pattern of sexual trait expression varies between populations through M/ANOVA and matrix correlations, 4) using discriminate function analyses, how well geometric morphometric analyses capture sexual trait expression compared to published rates, and 5) through M/ANOVA and discriminant function analyses, which intraindividual skeletal regions are the most accurate in sex classification analyses compared to others. For each skeletal element, landmarks were placed on each scan and sexual trait expression and an intra observer placement study was conducted. The landmark configurations were then subjected to a generalized Procrustes analysis, variance- covariance matrices were generated, and a principal component (PC) analyses in MorphoJ for combined sex data, derived male and females from combined sex data, and for independently input males and females. PCs were visually interpreted and subjected to M/ANOVA for three age groups: 18-29, 30-45, and 45 and older. PCs were then subjected to stepwise linear discriminant function analyses with leave- one-out cross validation. The first five PCs for each element were then utilized for a matrix correlation test and evaluated using a strength of correlation test (Chan et al 2003) and for significance using a Pearson’s correlation test. Results indicate that for intraobserver error is low, with scores being mostly considered excellent in reliability. For UTK data, shape changes associated with sexual trait classification were found for each of the five elements. Within these tests, many influential regions were known to sex estimation analyses, but other, such as the basicranium are currently underutilized. M/ANOVA revealed that sex was significant for all five skeletal elements, with some contributions from age and ancestry impacting sexual trait expression, however these interactions were not within a consistent pattern. Through the results of the discriminant function analyses, it appears some skeletal elements, such as the os coxae, scored higher correct classification rates than those reported in the literature, while others were on par or below reported rates. The os coxae and regions around it, were the best elements for correct sex classification accuracy, with the scapula rated as the worst. In the Terry data, sexual trait related shape changes are presented for each of the skeletal elements studied. Known morphological regions, as well as some more subtle ones, were found to be influential. M/ANOVA revealed that all elements, but the scapula had statistically significant shape changes present for sex estimation. Age and ancestry appear to contribute minimally to sexual trait morphology, but again, not in a way that is consistent, either within the collection or similarly to UTK. By examining the discriminant function analyses, some correct sex-estimation rates were on higher or on par with those reported in the literature, but others, such as the scapula were lower. This may be due the size being a larger contributor for sex estimation than shape, and the geometric morphometric analyses minimizing its effects in these analyses. Also using these tests, the os coxae was selected as the best element for high levels of sex classification accuracy, but which element was next best was different than the UTK results. This likely indicates biocultural influences are affecting sexual trait morphology and should be considered in future analyses. Significant inter-element correlations were detected in both skeletal collections, with UTK having more pairings than Terry. The most common and most statistically significant inter-element correlation across collections was between the cranium-mandible, which may be reflective of the integrated nature of these two elements. Different element correlations existed between each collection, with no clear pattern in pairings present in both collections, which may suggest that biocultural influences are impacting sexual trait expression. However, in both collections, females had more overall correlations, and more statistically significant correlations than males, although there was less of a difference between sexes in Terry than in UTK. This result may be due to circulating hormones present during puberty, which may be contributing to more correlation between elements in females and not males. It also suggests that once again, biocultural differences between the Terry and UTK collections may be impacting the magnitude and patterns of correlation. This research highlights the complex dynamic nature of sexual trait expression in bone in relation to several intrinsic and extrinsic factors. It supports the idea that sexual trait expression is not concordant between skeletal regions among the same individual and that these inter-element correlations appear to be different between skeletal collections. Likewise, it suggests that age and ancestry may minimally be affecting sexual trait expression, but not in a consistent way across skeletal elements or between collections. It also suggests that while geometric morphometrics may help in capturing shape variation, it does not always translate to higher correct classification rates. This research also supports previous literature that the os coxae is the best element for sex estimation, although is not clear on what element is next best. Future studies in sexual trait expression should account for biocultural influences, as this research suggests that sexual trait expression is influenced by poorly understood intrinsic and extrinsic factors.

Almost a century after its discovery, superconductivity (SC) is still the most challenging and fascinating topic in condensed matter physics. Organic superconductors show exotic phases and phase transitions with a change in temperature or pressure. In this dissertation, we studied the phases and phase-transitions in one-dimensional (1D) and two-dimensional (2D) organic materials. This dissertation itself is a group of three sub-projects. In project (i), we studied the properties of a novel state “paired electron crystal” (PEC) in the quarterfilled Hubbard model to understand the phases and properties of 2D organic materials. We also studied the effects of charge and spin frustration on the 2D strongly correlated quarterfilled band. Our conclusions are based on exact diagonalization (ED) studies that include electron-electron and adiabatic electron-phonon interactions. For moderate to strong frustration, the dominant phase is a novel spin-singlet PEC. We discuss the implications of the PEC concept for understanding several classes of quarterilled band materials that display unconventional superconductivity. In project (ii), we studied the thermodynamics of a zigzag ladder model, applicable to quasi-1D organic materials. Using the quantum Monte Carlo (QMC) method, we studied the thermodynamics of charge ordering in quarterilled quasi-1D organic charge transfer solids (CTS). Previous theoretical studies on these CTS have focused on ground state properties or purely 1D systems. In the zigzag ladder, no separate high-temperature ordering is expected; instead the ladder is metallic at high temperature, and as temperature decreases, a single transition to the PEC state with a spin-gap takes place. In project (iii), we studied superconducting pairing correlation and metal-insulator transitions in the halfilled Hubbard model. We employed the Hubbard model and used the path integral renormalization group (PIRG) method for this study. Antiferromagneticmediated SC was suggested for small to large frustration in anisotropic triangular lattices. Previous work on the halfilled Hubbard model using the ED method was successful in showing the absence of d-wave SC on a small anisotropic triangular lattice. We extended this study to larger lattices to investigate the existence of long-range order of superconducting pair-pair correlations. We also show the absence of d-wave SC in this model on larger lattices.

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