797 research outputs found
An admissible estimator for the rth power of a bounded scale parameter in a subclass of the exponential family under entropy loss function
We consider an admissible estimator for the rth power of a scale parameter that is lower or upper bounded in a subclass of the scale-parameter exponential family under the entropy loss function. An admissible estimator for a bounded parameter in the family of transformed chi-square distributions is also given.Розглянуто допустиму оцiнку для r-го степеня параметра масштабу, обмеженого зверху або знизу у пiдкласi експоненцiальної сiм’ї параметрiв масштабу з ентропiйною функцiєю втрат. Наведено також допустиму оцiнку обмеженого параметра у сiм’ї трансформованих розподiлiв хi-квадрат
An admissible estimator for the rth power of a bounded scale parameter in a subclass of the exponential family under entropy loss function
We consider an admissible estimator for the rth power of a scale parameter that is lower or upper bounded in a subclass of the scale-parameter exponential family under the entropy loss function. An admissible estimator for a bounded parameter in the family of transformed chi-square distributions is also given.Розглянуто допустиму оцiнку для r-го степеня параметра масштабу, обмеженого зверху або знизу у пiдкласi експоненцiальної сiм’ї параметрiв масштабу з ентропiйною функцiєю втрат. Наведено також допустиму оцiнку обмеженого параметра у сiм’ї трансформованих розподiлiв хi-квадрат
Discrete least squares meshless method for modeling 2D crack problems
In this paper, Discrete Least Squares meshless method (DLSM) is developed to analyze cracked structuresin an elastostatic problem. DLSMis a new really meshless method that does not use any mesh in computation. The method is based on the minimization of the least squares functional with respect to the nodal parameters. The least squares functional are formed as the weighted summation of the residual of the differential equation and its boundaryconditions. In thismethod, the domain of problem is discretized bysome nodesthat are used to produce Moving Least Squares shape functions. This type of discretization eliminates the Finite Element Method shortcomings. In this study, diffraction method was used to produce continuous shape functions around the crack. In diffraction method, the domain of influence wrap around the crack tip and it results in continuous derivatives of shape functions. Finally, the DLSM high efficiency and accuracy is presented by comparing the analytical results with numerical ones
A test for normality based on the empirical distribution function
In this paper, a goodness-of-fit test for normality based on the comparison of the theoretical and empirical distributions is proposed. Critical values are obtained via Monte Carlo for several sample sizes and different significance levels. We study and compare the power of forty selected normality tests for a wide collection of alternative distributions. The new proposal is compared to some traditionaltest statistics, such as Kolmogorov-Smirnov, Kuiper, Cramér-von Mises, Anderson-Darling, Pearson Chi-square, Shapiro-Wilk, Shapiro-Francia, Jarque-Bera, SJ, Robust Jarque-Bera, and also to entropy-based test statistics. From the simulation study results it is concluded that the best performance against asymmetric alternatives with support on the whole real line and alternative distributions with support on the positive real line is achieved by the new test. Other findings derivedfrom the simulation study are that SJ and Robust Jarque-Bera tests are the most powerful ones for symmetric alternatives with support on the whole real line, whereas entropy-based tests are preferable for alternatives with support on the unit interval
Water management for sustainable irrigated agriculture in the Zayandeh Rud Basin, Esfahan Province, Iran
Irrigation systemsCropping systemsIrrigated farmingRiver basinsTopographyGeomorphologyClimateHydrologyWater qualityGroundwaterSoil salinitySustainable agricultureIranEsfahan ProvinceZayandeh Rud BasinChadegan Reservoir
Effect of salinity on Na+ and K+ compartmentation in salt tolerant and sensitive wheat genotypes
Success Rate and Complications of Internal Jugular Vein Catheterization With and Without Ultrasonography Guide
Background: Central venous catheterization (CVC) is an important procedure in emergency departments (EDs). Despite existence of ultrasonography (US) devices in every ED, CVC is done using anatomical landmarks in many EDs in Iran.
Objectives: This study aimed to compare the traditional landmark method vs. US-guided method of CVC placement in terms of complications and success rate.
Patients and Methods: In this randomized controlled trial, patients who were candidate for internal jugular vein catheterization, and referred to Baqiyatallah Hospital ED were randomly allocated into US-guided CVC and anatomical landmarks guided CVC groups. Central vein access time, number of attempts, success rate, and complications in each group were evaluated. Mann-Whitney U, chi-square and Fisher exact tests along with Pearson and Spearman correlation coefficients were used to analyze the data.
Results: Out of 100 patients, 56 were male and 44 were female. No significant differences were found between the US-guided and traditional landmark methods of CVC insertion in terms of age, gender, BMI, and site of catheter insertion. The mean access time was significantly lower in the US-guided group (37.12 ± 17.33 s vs. 63.42 ± 35.19 s, P < 0.001). The mean number of attempts was also significantly lower in the US-guided group (1.12 ± 0.3 vs. 1.58 ± 0.64 times, P < 0.001). Eighty-eight percent of patients in the US-guided group were catheterized in the first attempt, while 50% of patients in the traditional landmark group were catheterized in the second or more attempts (P < 0.001). The success rate was 100% in the US-guided group, while it was 88% in the landmark group (P = 0.013). Moreover, the rate of complications was significantly lower in the US-guided group (4% vs. 24%, P = 0.004).
Conclusions: The US-guided method for CVC placement was superior to the traditional landmark method in terms of access time, number of attempts, success rate, and fewer complications
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