Miracle-dz/UniFAR-FTUs huggingface dataset:
A Bayesian hierarchical model for risk assessment of methylmercury

This article uses a Bayesian hierarchical model to quantify the adverse health effects associated with in-utero exposure to methylmercury. By allowing for study-to-studyas well as outcome-to-outcome variability, the approach provides a useful meta-analytic tool for multi-outcome, multi-study environmental risk assessments. The analysis presented here expands on the findings of a National Academy of Sciences (NAS) committee, charged with advising the United States Environmental Protection Agency (EPA) on an appropriate approach to conducting a risk assessment for methylmercury. The NAS committee, for which the senior author (Ryan) was a committee member, reviewed the findings from several conflicting studies and reported the results from a Bayesian hierarchical model that synthesized information across several studies and for several outcomes. Although the NAS committee did not suggest that the hierarchical model be used as the actual basis for a methylmercury risk assessment, the results from the model were used to justify and support the final recommendation that the risk analysis be based on data from a study conducted in the Faroe Islands, which had found a positive association between in-utero exposure to methylmercury and impaired neurological development. We considera variety of statistical issues, but particularly sensitivity to model specification.
Absolute gravimetry in a shifted Legendre basis

A formalism, based on standard least squares techniques, is presented in which analytic expressions can be derived for the study of the influence of hypothetic perturbations in absolute gravimetry. The model function derived from the equation of motion of the test mass and possible perturbations is expanded in an orthogonal basis composed of the shifted Legendre polynomials, and projections onto the model space and the space orthogonal to this serve to isolate the contributions to the model parameters and to the residuals. The part of the perturbation remaining in the orthogonal space can be compared with those retrieved from the residuals of the fit of the model function to the experimental data. The analysis of the structure of these residuals is a major means of gaining information about the character of the perturbations. Finally, some explicit examples are given and a discussion concerning how such an analysis can be made is included.
The Variance of the Product of K Random Variables

Abstract An exact formula for the variance of the product of K random variables, x 1, x 2, ···, x K , is given as a function of the means and the central product-moments of the xi . The usual approximate variance formula for is compared with the exact formula; e.g., we note, in the case where the x i are mutually independent, that the approximate variance is too small, and that the relative accuracy of the approximation depends on the magnitude of the coefficients of variations of the K random variables. The case where the x i need not be mutually independent is also studied, and variance formulas are presented for two different “product estimators. ” (The relative magnitude of the variances of these estimators is shown to be related to the relative accuracy of the approximate variance formula for as compared with the exact variance formula.) When the x i are mutually independent, simple unbiased estimators of these variances are suggested; in the more general case, consistent estimators are presented.
On the luminous efficiency of meteoritic fireballs

Luminous efficiency values have been calculated empirically as a function of velocity and altitude for the Lost City, Innisfree, and Pribram meteorites. We have used a combined approach which utilizes the observed light data from the meteorite entries and the appropriate ablation rates via the entry model of ReVelle, which is generally consistent with the results of cosmic ray track analyses. Although our method reduces the absolute value of computed luminous efficiency via a total kinetic power balance equation, our results still exceed the modified Trailblazer results of Ceplecha and McCrosky for chondrites by about a factor of 5 for entry velocities of ≲20 km/s. Our values of luminous efficiency (deduced with respect to a detector peaked in the visible) are ∼0.2–0.4% in the vicinity of peak ablation for Lost City and Innisfree, respectively. Results for Pribram are less certain but are ∼0.04% at peak ablation. In terms of numerical values and velocity dependencies our results agree well with appropriately modified laboratory simulation data of Givens and Page (1971). We conclude that the deduced photometric mass scale of fireballs should be revised downward by a factor of 5–10 so that a more accurate mass influx determination at the earth's orbit can be made.
An investigation into the attenuation of wind speed by the use of windbreaks in the vicinity of overhead wires

Abstract An experimental and computational analysis of the efficacy of windbreaks for the attenuation of wind speed in the vicinity of overhead wires is presented. This work has been specifically applied to the case of oscillation of overhead catenary contact wires in a cross-wind. A wind tunnel subscale model of a windbreak/overhead wire configuration is presented and discussed with regard to the feasibility of reducing the aerodynamically induced oscillations encountered in such situations. This porous blockage placed upstream of the simulated overhead wire attempts to represent the influence of a windbreak/shelterbelt on the reduction of the vibration phenomenon known as galloping. In conjunction with this experimental study, a computational fluid dynamics (CFD) analysis has been carried out in order to assess the influence of the shelterbelt on the catenary wires in a typical full-scale scenario. The results indicate that a dense shelterbelt of height H positioned between 2-8 tree heights, H, upstream of the suspended cables provides a sufficient reduction in wind speed to reduce significantly the amplitude of wire vibration.
The Shape of Things: But Not the Golden Section

For two-dimensional rectangular objects, a fundamental characteristic is the ratio of height and width. Ratios were calculated for paintings that are both high art and popular art. They show excellent agreement in both the shapes of the distributions and the medians of approximately 1.3. Ratios were calculated for two-dimensional art supplies and other objects. With some exceptions, the representative ratios for many of these objects are also close to 1.3. Two mathematical ratios are suggested. One is 4:3, found in the first Pythagorean triple, the three sides of a right triangle. The other is the plastic number studied by Richard Padovan. Although neither has the status of the golden section, either ratio would be a better candidate for describing the regularity in the proportions of rectangular objects.
Probabilistic evidence combination for robust real time finger recognition and tracking

This thesis sets out a Bayesian approach to the robust combination of measurements from multiple sensors in different measurement spaces. Classical least squares optimization is used inside a sequential Monte Carlo approach to find the most likely local estimate. The local optimization speeds up the system, while the Monte Carlo approach improves robustness in finding the globally optimal solution. Models are simultaneously fit to all the sensor data. A statistical approach is taken to determine when inputs are failing and should be ignored. To demonstrate the overall approach described in this thesis, the 3D position and orientation of highly over-constrained models of deformable objects—fingers—are tracked. Accurate results are obtained by combining features of color and stereo range images. The multiple sources of information combined in this work include stereo range images, color segmentations, shape information and various constraints. The system is accurate and robust; it can continue to work even when one of the sources of information is completely failing. The system is practical in that it works in real time and can deal with complex moving backgrounds that have many edges, changing lighting, and other real world vision challenges.
Magnetorheological carbonyl iron particles doubly wrapped with polymer and carbon nanotube

To improve magnetorheological (MR) characteristics of carbonyl iron (CI) microparticles, we introduce two-step CI coating procedures with poly(methyl methacrylate) (PMMA) and multiwalled carbon nanotube (MWNT) for the first time. Core(CI)-shell(PMMA) (CI-PM) structured composite magnetic microbeads were synthesized by dispersion polymerization first, showing improved dispersion stability and sedimentation quality. However, its magnetic strength was decreased compared with that of pristine CI-based MR fluid. To enhance its magnetic strength, the core-shell type CI-PM particles were wrapped with MWNT via ultrasonication. Rheological properties of their MR fluid were measured by a rotational rheometer with a magnetic field supplier. The CI-PMMA-MWNT (CI-PM-NT) particles were found to show better flow and dynamic rheological properties compared to those from CI-PM particles while density of the CI-PM-NT particles was not much different from that of CI-PM, implying that sedimentation stability of the CI-PM-NT .
The Response of a Spectral General Circulation Model to Refinements in Radiative Processes

Abstract We present here results and analyses of a series of numerical experiments performed with a spectral general circulation model (GCM). The purpose of the GCM experiments is to examine the role of radiation/cloud processes in the general circulation of the troposphere and stratosphere. The experiments were primarily motivated by the significant improvements in the GCM zonal mean simulation as refinements were made in the model treatment of clear-sky radiation and cloud-radiative interactions. The GCM with the improved cloud/radiation model is able to reproduce many observed features, such as: a clear separation between the wintertime tropospheric jet and the polar night jet; winter polar stratospheric temperatures of about 200 K; interhemispheric and seasonal asymmetries in the zonal winds. In a set of sensitivity experiments, we have stripped the cloud/radiation model of its improvements, the result being a significant degradation of the zonal mean simulations by the GCM. Through these experiments .
Comparison of the finite mixture of ARMA-GARCH, back propagation neural networks and support-vector machines in forecasting financial returns

The use of GARCH type models and computational-intelligence-based techniques for forecasting financial time series has been proved extremely successful in recent times. In this article, we apply the finite mixture of ARMA-GARCH model instead of AR or ARMA models to compare with the standard BP and SVM in forecasting financial time series (daily stock market index returns and exchange rate returns). We do not apply the pure GARCH model as the finite mixture of the ARMA-GARCH model outperforms the pure GARCH model. These models are evaluated on five performance metrics or criteria. Our experiment shows that the SVM model outperforms both the finite mixture of ARMA-GARCH and BP models in deviation performance criteria. In direction performance criteria, the finite mixture of ARMA-GARCH model performs better. The memory property of these forecasting techniques is also examined using the behavior of forecasted values vis-à-vis the original values. Only the SVM model shows long memory property in forecasting financial returns.
On the Clustering Tendencies among the Nebulae. II. a Study of Encounters Between Laboratory Models of Stellar Systems by a New Integration Procedure.

In a previous paper the writer discussed the possibility of explaining the observed clustering effects among extragalactic nebulae as a result of captures. The present investigation deals with the important problem of whether the loss of energy resulting from the tidal disturbances at a close encounter between two nebulae is large enough to effect a capture. The tidal deformations of two models of stellar systems, passing each other at a small distance, are studied by reconstructing, piece by piece, the orbits described by the individual mass elements. The difficulty of integrating the total gravitational force acting upon a certain element at a certain point of time is solved by replacing gravitation by light. The mass elements are represented by light-bulbs, the candle power being proportional to mass, and the total light is measured by a photocell (Fig. i). The nebulae are assumed to have a flattened shape, and each is represented by 37 light-bulbs. It is found that the tidal deformations cause an increase in the attraction between the two objects, the increase reaching its maximum value when the nebulae are separating, i.e., after the passage. The resulting loss of energy (Fig. 6) is comparatively large and may, in favorable cases, effect a capture. The spiral arms developing during the encounter (Figs. 4) represent an interesting by-product of the investigation. The direction of the arms depends on the direction of rotation of the nebulae with respect to the direction of their space motions. I. THE EXPERIMENTAL ARRANGEMENTS The present paper is a study of the tidal disturbances appearing in stellar systems which pass one another at small distances. These tidal disturbances are of some importance since they are accompanied by a loss of energy which may result in a capture between the two objects. In a previous paper the writer discussed the clustering tendencies among extragalactic nebulae. A theory was put forth that the observed clustering effects are the result of captures between individual nebulae. The capture theory seems ' to be able to account not only for double and multiple nebulae but also for the large^ extragalactic clusters. The present investigation tries to give an answer to the importarit question of whether the loss of energy accompanying a close encounter between two nebulae is large enough to effect a capture. , A study of tidal disturbances is greatly facilitated if it can be restricted to only two dimensions, i.e., to nebulae of a flattened shape, the principal planes of which coincide with the plane of their hyperbolic orbits. In order to reconstruct the orbit described by 1 Mt. W. Contr. , No. 633; Ap. 92, 200, 1940.
Patterns of infections and antimicrobial susceptibility in elderly patients: Long term care based study

Objective: This study has been conducted to determine Patterns of infections and antimicrobial susceptibility in elderly patients admitted to long term care at a tertiary care hospital in Saudi Arabia, Eastern province to guide rationale for antibiotic use and prevent resistance. Materials & Methods: A total of 100 specimens were collected from100 elderly patients ≥ 60years, both males and females admitted to long term care in a tertiary hospital in Dammam city, Eastern province, Saudi Arabia during the year 2022. Collected specimens included forty urine samples , forty sputum samples and twenty swabs from infected pressure ulcers . All collected specimens were sent for bacterial culture and sensitivity, bacterial species were determined by conventional methods and disk diffusion was used to determine the antimicrobial susceptibility pattern of the bacteria isolates after 48 hours incubation. Results: Out of the 100 cultured specimens, 118 pathogens were detected in the whole sample where Gram-negative bacteria: primarily, Klebsiella pneumoniae (32.2%) followed by pseudomonas aeruginosa (20.3%) then Acinetobacter bumannii (14.4%) represented the most prevalent pathogens. High percentage of multidrug resistant pathogens (MDR) was detected mostly among Acinetobacter 60% followed by pseudomonas 35% then E-coli 33%. Antibiotic sensitivity was variable among different pathogens, gram negative pathogens sensitivity was generally high mainly to amino glycosides and carbapenems groups.
Monte Carlo calculations of the radial distribution functions for a proton-electron plasma

A general method is presented for computation of radial distribution functions for plasmas over a wide range of temperatures and densities. The method uses the Monte Carlo technique applied by Wood and Parker, and extends this to long-range forces using results borrowed from crystal lattice theory. The approach is then used to calculate the radial distribution functions for a proton-electron plasma of density 1018 electrons/cm3 at a temperature of 104 OK. The results show the usefulness of the method if sufficient computing facilities are available.
Quasilinear elliptic problems with boundary blow-up

A classical problem in differential geometry is the prescribed curvature problemin a bounded domain, where the task is to conformally deform the Euclidean metric to another complete Riemannian metric with a prescribed curvature function.If this function is negative, the problem is equivalent to solving a nonlinear elliptic partial differential equation with boundary blow-up. The problem is solvablein non-tangentially accessible domains, a class including the well-known vonKoch snowflake, and there are estimates of the behaviour of the solution at anypoint close to the boundary in terms of the distance from the point to the boundary. There is a characterization of the negative continuous functions for whichthe prescribed curvature problem is solvable. Another result is the existence ofa unique distribution solution of a particular boundary-blow-up problem relevant in probability theory, in any bounded domain. If the Laplace operator in the original problem is exchanged for the pseudo-Laplace operator or the real Monge-Ampere operator, it is still possible to state necessary and sufficient growth conditions on the nonlinear absorption term, which depends on the solution, for the corresponding problem to be solvable. Blow-up estimates andsome uniqueness results hold. The behaviour of a solution in a ball determineswhether there does or does not exist an entire solution of the equation, i.e. asolution defined throughout the Euclidean space. Existence results and growthestimates for solutions of a generalized mean curvature flow problem follow fromthe general technique which is the foundation of all the results in the thesis.
Linear and nonlinear instabilities of a Blasius boundary layer perturbed by streamwise vortices. Part 2. Intermittent instability induced by long-wavelength Klebanoff modes

This paper presents theoretical results on the instability of a Blasius boundary layer perturbed by Klebanoff modes (i.e. the low-frequency streaks known to be induced by free-stream turbulence). Herein, the Klebanoff distortions are modelled as the signature of a three-dimensional convected gust that may be either isolated or periodic along the spanwise direction. Relatively weak Klebanoff fluctuations can produce $O(1)$ changes tothe near-wall curvature of the base flow profile and, hence, fundamentally alter the nature of its instability characteristics.The perturbed flow is shown to support instabilities that are predominantly inviscid and have significantly larger growth rates and characteristic frequencies than the Tollmien–Schlichting(T–S) modes of an unperturbed Blasius flow. The spanwise mode shape of instabilities in the perturbed flow is determined by theSchrödinger equation, with a potential function that corresponds to the skin friction perturbation due to the Klebanoff distortion. The growth ratesof these modes are determined by the near-wall torsion of the perturbed flow.The unsteadiness of the Klebanoff distortion is shown to be a crucial element in determining the overall instability characteristics.
Approximation multi-échelles de l’équation de Vlasov

Une des difficultes fondamentales de la simulation numerique de plasmas magnetises est l'existence d'echelles de temps et d'espace mettant en jeu plusieurs ordres de grandeurs tres differents. Afin de realiser des simulations numeriques efficaces de ces phenomenes physiques, il est essentiel de developper des modeles et des methodes numeriques adaptes a ces problemes. A ce jour, la notion de convergence 2-echelles introduite par G. Allaire et G. Nguetseng est un des outils permettant de deriver rigoureusement des limites multi-echelles, ce qui nous permet d'obtenir des modeles limites qu'il est possible de discretiser avec une methode numerique usuelle : nous parlons alors d'une methode numerique 2-echelles. L'objectif de cette these est de developper une methode semi-lagrangienne 2 echelles sur un modele de type Vlasov gyrocinetique afin de simuler un plasma soumis a un champ magnetique fort du meme type que ceux utilises pour le projet ITER. Cependant, comme les phenomenes physiques a simuler sont assez complexes et comme nous ne savons que peu de choses sur le comportement d'une methode numerique 2-echelles sur un modele non-lineaire, il convient de proceder par etapes avant de developper une telle methode sur un modele gyrocinetique. Dans une premiere partie, nous construisons une methode de volumes finis 2-echelles sur les equations d'Euler 1D isentropiques faiblement compressibles. Bien que ce modele soit assez different d'un modele de type Vlasov, il n'en est pas moins un cadre de travail relativement simple pour etudier le comportement d'une methode numerique 2-echelles face a un modele non-lineaire. Dans une seconde partie, nous nous basons sur le modele limite developpe par E. Frenod, F. Salvarani et E. Sonnendrucker afin de construire une methode semi-lagrangienne 2-echelles pour simuler des faisceaux de particules en geometrie axisymetrique. Meme si le modele de Vlasov axisymetrique utilise est different d'un modele gyrocinetique, il constitue un contexte ideal pour etablir les bases d'une methode semi-lagrangienne 2 echelles. Enfin, dans une troisieme partie, nous utilisons la convergence 2-echelles afin d'ameliorer les resultats de convergence faible-* etablis par M. Bostan en 2007, et nous proposons une methode semi-lagrangienne en avant permettant de valider numeriquement ces resultats.
Large-Amplitude Vibration Analysis of Shear Deformable Laminated Composite Cylindrical Shells with Initial Imperfections in Thermal Environments

Large-amplitudevibrationanalysisforasheardeformablecross-plylaminatedcompositecylindricalshellof finitelengthinthermal environmentsispresented.Thematerialofeachlayeroftheshellisassumedtobelinearlyelasticand fiberreinforced.Themotionequationsare basedonReddy's higher-order shear deformation shell theory with a von Karman-Donnell-type of kinematic nonlinearity. The thermal effects and initial imperfections of the shell are both taken into account. A two-step perturbation technique is employed to determine the linear and nonlinear frequency of the laminated cylindrical shells. The numerical illustrations concern the nonlinear vibration behavior of laminated composite cylindrical shells with different values of geometric parameters and different cases of thermal environmental conditions. The results showthattheshellhasrelativelylowernaturalfrequencieswhenthetemperature-dependentpropertiesaretakenintoaccount.Theresultsreveal that the temperature changes, initial imperfections of the shell, and the shell geometric parameter have significant effects on the nonlinear vibration behavior of laminated composite cylindrical shells. DOI: 10.1061/(ASCE)EM.1943-7889.0000675. © 2014 American Society of Civil Engineers. Authorkeywords:Cross-plylaminatedcomposites;Cylindrical shell;Higher-ordersheardeformationshelltheory;Temperature-dependent properties; Large-amplitude vibration.