Analyzing the effect of rating of liquidity, profitability ratios and dividend on performance of accepted investment companies in Tehran stock exchange

Investment companies as one of the financial brokers have put into action the forming of the various and vast portfolio through selling their stocks. Their advantages include reduced investment risk due to a variety of stock basket and flexibility in decision-making due to possessing massive cash. These companies should consider elements, such as the power of liquidity, profitability ratios and dividend of the companies. The aim of this paper is analyzing the influence of those mentioned elements on the performance of the investor companies according to two indices of Sharp and Trainer. In achieving this goal, the factors such as risk, portfolio feedback, beta, liquidity rate, profitability ratios, dividend and the amount of Sharp and Trainer indices, were computed for companies’ portfolio and by using T-test and comparing the mean of two populations and regression, the hypothesis was being studied. The results of the study indicate that the liquidity rating was influenced on investment companies on the basis of Sharp, but profitability ratios and dividend have no influence on the performance of the companies. By reviewing the leaner connection between the efficiency portfolio of investment companies by the liquidity rating and profitability and dividend, the results were similar

Analyzing the effect of rating of liquidity, profitability ratios and dividend on performance of accepted investment companies in Tehran stock exchange

Investment companies as one of the financial brokers have put into action the forming of the various and vast portfolio through selling their stocks. Their advantages include reduced investment risk due to a variety of stock basket and flexibility in decision-making due to possessing massive cash. These companies should consider elements, such as the power of liquidity, profitability ratios and dividend of the companies. The aim of this paper is analyzing the influence of those mentioned elements on the performance of the investor companies according to two indices of Sharp and Trainer. In achieving this goal, the factors such as risk, portfolio feedback, beta, liquidity rate, profitability ratios, dividend and the amount of Sharp and Trainer indices, were computed for companies’ portfolio and by using T-test and comparing the mean of two populations and regression, the hypothesis was being studied. The results of the study indicate that the liquidity rating was influenced on investment companies on the basis of Sharp, but profitability ratios and dividend have no influence on the performance of the companies. By reviewing the leaner connection between the efficiency portfolio of investment companies by the liquidity rating and profitability and dividend, the results were similar

Analyzing the effect of rating of liquidity, profitability ratios and dividend on performance of accepted investment companies in Tehran stock exchange

Investment companies as one of the financial brokers have put into action the forming of the various and vast portfolio through selling their stocks. Their advantages include reduced investment risk due to a variety of stock basket and flexibility in decision-making due to possessing massive cash. These companies should consider elements, such as the power of liquidity, profitability ratios and dividend of the companies. The aim of this paper is analyzing the influence of those mentioned elements on the performance of the investor companies according to two indices of Sharp and Trainer. In achieving this goal, the factors such as risk, portfolio feedback, beta, liquidity rate, profitability ratios, dividend and the amount of Sharp and Trainer indices, were computed for companies’ portfolio and by using T-test and comparing the mean of two populations and regression, the hypothesis was being studied. The results of the study indicate that the liquidity rating was influenced on investment companies on the basis of Sharp, but profitability ratios and dividend have no influence on the performance of the companies. By reviewing the leaner connection between the efficiency portfolio of investment companies by the liquidity rating and profitability and dividend, the results were similar

Relationship Between Carotid Intima-Media Thickness with some Inflammatory Biomarkers, Ghrelin and Adiponectin in Iranians with and without Metabolic Syndrome in Isfahan Cohort Study

<p class="abstract"><strong>BACKGROUND:</strong> Recent studies have confirmed inflammatory factors and metabolic syndrome (MetS) as important cardiovascular disease (CVD) risk factors. Recently measurement of carotid intima-media thickness (IMT) has been used for evaluation of early atherosclerosis. This study was designed to assess the correlation between IMT with some inflammatory biomarkers, ghrelin and adiponectin in people with and without MetS in a cohort sample in Isfahan province.</p> <p class="abstract"><strong>&nbsp;&nbsp; METHODS:</strong><strong> </strong>Among participants of Isfahan Cohort Study (ICS) by random sampling, 88<strong> </strong>participants were selected and divided into case (with MetS) and control (without MetS)&nbsp;&nbsp; groups. A questionnaire including demographic data and CVD risk factors was completed for all of the participants. Physical examination and blood pressure, height, weight and waist circumference measurements were done for all subjects. Vascular echocardiography was done for evaluation of IMT of each carotid artery of both sides. Interlukin-6 (IL-6), interlukin-10 (IL-10), highly sensitive C-reactive protein (hs-CRP), ghrelin and adiponectin levels were measured using ELIZA method. Data were entered in SPSS version 15 and analyzed by t test, chi square, Pearson correlation and linear regression analyze.</p> <p class="abstract"><strong>&nbsp;&nbsp; RESULTS:</strong> The mean waist circumference, BMI, systolic blood pressure, diastolic blood pressure, hs &ndash;CRP and IMT of left carotid artery were significantly higher in participants with Mets. There was significant correlation between left carotid IMT and IL-6 level in all patients (P=0.03). After adjustment for age and sex, significant relationship in groups with MetS was only reported between the left IMT and IL-6 (P=0.02). There was no relation between IMT and other inflammatory markers in subjects with and without MetS.</p> <p class="abstract"><strong>&nbsp;&nbsp; </strong><strong>CONCLUSION:</strong> Significant correlation between IL-6 and IMT was reported in patients with MetS. While no significant correlation between IL-10, adiponectin and ghrelin with IMT was observed in metabolic syndrome group.</p> <p class="abstract">&nbsp;</p><table cellspacing="0" cellpadding="0" align="left"><tbody><tr><td width="35" height="12"><br /></td></tr> <tr><td><br /></td> <td>&nbsp;</td></tr></tbody></table><p class="abstract">&nbsp;</p> <strong>Keywords:</strong> Intima-media thickness (IMT), carotid artery, hs-CRP, Ghrelin, Adiponectin IL-6, IL-10

Rates of contraction of posterior distributions based on p-exponential priors

We consider a family of infinite dimensional product measures with tails between Gaussian and exponential, which we call p-exponential measures. We study their measure-theoretic properties and in particular their concentration. Our findings are used to develop a general contraction theory of posterior distributions on nonparametric models with p-exponential priors in separable Banach parameter spaces. Our approach builds on the general contraction theory for Gaussian process priors in (Ann. Statist. 36 (2008) 1435–1463), namely we use prior concentration to verify prior mass and entropy conditions sufficient for posterior contraction. However, the specific concentration properties of p-exponential priors lead to a more complex entropy bound which can influence negatively the obtained rate of contraction, depending on the topology of the parameter space. Subject to the more complex entropy bound, we show that the rate of contraction depends on the position of the true parameter relative to a certain Banach space associated to p-exponential measures and on the small ball probabilities of these measures. For example, we apply our theory in the white noise model under Besov regularity of the truth and obtain minimax rates of contraction using (rescaled) α-regular p-exponential priors. In particular, our results suggest that when interested in spatially inhomogeneous unknown functions, in terms of posterior contraction, it is preferable to use Laplace rather than Gaussian priors. However, the specific concentration properties of $p$-exponential priors lead to a more complex entropy bound which can influence negatively the obtained rate of contraction, depending on the topology of the parameter space. Subject to the more complex entropy bound, we show that the rate of contraction depends on the position of the true parameter relative to a certain Banach space associated to $p$-exponential measures and on the small ball probabilities of these measures. For example, we apply our theory in the white noise model under Besov regularity of the truth and obtain minimax rates of contraction using (rescaled) $\alpha$-regular $p$-exponential priors. In particular, our results suggest that when interested in spatially inhomogeneous unknown functions, in terms of posterior contraction, it is preferable to use Laplace rather than Gaussian priors

Besov priors for Bayesian inverse problems

We consider the inverse problem of estimating a function $u$ from noisy, possibly nonlinear, observations. We adopt a Bayesian approach to the problem. This approach has a long history for inversion, dating back to 1970, and has, over the last decade, gained importance as a practical tool. However most of the existing theory has been developed for Gaussian prior measures. Recently Lassas, Saksman and Siltanen (Inv. Prob. Imag. 2009) showed how to construct Besov prior measures, based on wavelet expansions with random coefficients, and used these prior measures to study linear inverse problems. In this paper we build on this development of Besov priors to include the case of nonlinear measurements. In doing so a key technical tool, established here, is a Fernique-like theorem for Besov measures. This theorem enables us to identify appropriate conditions on the forward solution operator which, when matched to properties of the prior Besov measure, imply the well-definedness and well-posedness of the posterior measure. We then consider the application of these results to the inverse problem of finding the diffusion coefficient of an elliptic partial differential equation, given noisy measurements of its solution.Comment: 18 page

The motion of a fluid-rigid disc system at the zero limit of the rigid disc radius

We consider the two-dimensional motion of the coupled system of a viscous incompressible fluid and a rigid disc moving with the fluid, in the whole plane. The fluid motion is described by the Navier-Stokes equations and the motion of the rigid body by conservation laws of linear and angular momentum. We show that, assuming that the rigid disc is not allowed to rotate, as the radius of the disc goes to zero, the solution of this system converges, in an appropriate sense, to the solution of the Navier-Stokes equations describing the motion of only fluid in the whole plane. We also prove that the trajectory of the centre of the disc, at the zero limit of its radius, coincides with a fluid particle trajectory.Comment: 29 pages, 0 figure

Some problems in the mathematical theory of fluid mechanics

This thesis addresses three problems related to the mathematical theory of fluid mechanics. Firstly, we consider the three-dimensional incompressible Navier-Stokes equations with an initial condition that has H1-Sobolev regularity. We show that there is an a posteriori condition that, if satisfied by the numerical solutions of the equations, guarantees the existence of a strong solution and therefore the validity of the numerical computations. This is an extension of a similar result proved by Chernyshenko, Constantin, Robinson ;Titi (2007) to less regular solutions not considered by them. In the second part, we give a simple proof of uniqueness of fluid particle trajectories corresponding to the solution of the d-dimensional Navier Stokes equations, d = 2, 3, with an initial condition that has H(d/2)−1-Sobolev regularity. This result has been proved by Chemin ;Lerner (1995) using the Littlewood-Payley theory for the flow in the whole space Rd. We provide a significantly simpler proof, based on the decay of Sobolev norms ( of order more than (d/2)−1 ) of the velocity field after the initial time, that is also valid for the more physically relevant case of bounded domains. The last problem we study is the motion of a fluid-rigid disk system in the whole plane at the zero limit of the rigid body radius. We consider one rigid disk moving with the fluid flow and show that when the radius of the disk goes to zero, the solution of this system converges, in an appropriate sense, to the solution of the Navier-Stokes equations describing the motion of only fluid in the whole plane. We then prove that the trajectory of the centre of the disk, at the zero limit of its radius, coincides with a fluid particle trajectory. We also show an equivalent result for the limiting motion of a spherical tracer in R3, over a small enough time interval.EThOS - Electronic Theses Online ServiceUniversity of WarwickGBUnited Kingdo

Some problems in the mathematical theory of fluid mechanics

This thesis addresses three problems related to the mathematical theory of fluid mechanics. Firstly, we consider the three-dimensional incompressible Navier-Stokes equations with an initial condition that has H1-Sobolev regularity. We show that there is an a posteriori condition that, if satisfied by the numerical solutions of the equations, guarantees the existence of a strong solution and therefore the validity of the numerical computations. This is an extension of a similar result proved by Chernyshenko, Constantin, Robinson & Titi (2007) to less regular solutions not considered by them. In the second part, we give a simple proof of uniqueness of fluid particle trajectories corresponding to the solution of the d-dimensional Navier Stokes equations, d = 2, 3, with an initial condition that has H(d/2)−1-Sobolev regularity. This result has been proved by Chemin & Lerner (1995) using the Littlewood-Payley theory for the flow in the whole space Rd. We provide a significantly simpler proof, based on the decay of Sobolev norms ( of order more than (d/2)−1 ) of the velocity field after the initial time, that is also valid for the more physically relevant case of bounded domains. The last problem we study is the motion of a fluid-rigid disk system in the whole plane at the zero limit of the rigid body radius. We consider one rigid disk moving with the fluid flow and show that when the radius of the disk goes to zero, the solution of this system converges, in an appropriate sense, to the solution of the Navier-Stokes equations describing the motion of only fluid in the whole plane. We then prove that the trajectory of the centre of the disk, at the zero limit of its radius, coincides with a fluid particle trajectory. We also show an equivalent result for the limiting motion of a spherical tracer in R3, over a small enough time interval