Some Improved Estimators In Systematic Sampling Under Non-response

In this paper we have considered the problem of estimating the population mean in systematic sampling using information on an auxiliary variable in presence of non response. Some modified ratio, product and difference type estimators in systematic sampling have been suggested and their properties are studied. The expressions of mean squared errors (MSEs) up to the first order of approximation are derived. An empirical study is carried out to judge the best estimator out of the suggested estimators.Comment: 13 pages, 1 table. arXiv admin note: text overlap with arXiv:1306.615

A CRITICAL STUDY AND COMPARISON OF MANUFACTURING SIMULATION SOFTWARES USING ANALYTIC HIERARCHY PROCESS

In a period of continuous change in global business environment, organizations, large and small, are finding it increasingly difficult to deal with, and adjust to the demands for such change. Simulation is a powerful tool for allowing designers imagines new systems and enabling them to both quantify and observe behavior. Currently the market offers a variety of simulation software packages. Some are less expensive than others. Some are generic and can be used in a wide variety of application areas while others are more specific. Some have powerful features for modeling while others provide only basic features. Modeling approaches and strategies are different for different packages. Companies are seeking advice about the desirable features of software for manufacturing simulation, depending on the purpose of its use. Because of this, the importance of an adequate approach to simulation software evaluation and comparison is apparent. This paper presents a critical evaluation of four widely used manufacturing simulators: NX-IDEAS, Star-CD, Micro Saint Sharp and ProModel. Following a review of research into simulation software evaluation, an evaluation and comparison of the above simulators is performed. This paper illustrates and assesses the role the Analytic Hierarchy Process (AHP) played in simulation software evaluation and selection. The main purpose of this evaluation and comparison is to discover the suitability of certain types of simulators for particular purposes

The effects of thermal radiation and viscous dissipation on MHD heat and mass diffusion flow past an oscillating vertical plate embedded in a porous medium with variable surface conditions

This investigation is undertaken to study the hydromagnetic flow of a viscous incompressible fluid past an oscillating vertical plate embedded in a porous medium with radiation, viscous dissipation and variable heat and mass diffusion. Governing equations are solved by unconditionally stable explicit finite difference method of DuFort - Frankel’s type for concentration, temperature, vertical velocity field and skin - friction and they are presented graphically for different values of physical parameters involved. It is observed that plate oscillation, variable mass diffusion, radiation, viscous dissipation and porous medium affect the flow pattern significantly

Characteristics of Fatal Cases of Pandemic Influenza A (H1N1) from September 2009 to January 2010 in Saurashtra Region, India

Background: India reported first case of 2009 pandemic influenza A (H1N1) virus infection in May, 2009 and Saurashtra region in August, 2009. We describe the characteristics of fatal cases of 2009 influenza A (H1N1) infection reported in Saurashtra region. Methods: From September, 2009 to January, 2010, we observed 71 fatal cases that were infected with 2009 influenza A (H1N1) virus and admitted in different hospitals in Rajkot city. Real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) testing was used to confirm infection; the clinico-epidemiological features were observed and documented. Results: Median age of the deceased (71) was 29 years, and 57.7% were females. Median time observed was 5 days from onset of illness to diagnosis of influenza A (H1N1), and 57.7% were referred from general practitioner (OR=0.42, CI=0.24-0.74). Median hospital stay reported was 3 days. All admitted patients received oseltamivir, but only 16.9% received it within 2 days of onset of illness. The most common symptoms were cough (97.2%), fever (93%), sore throat and shortness of breath. Co-morbid conditions were present in almost half of the patients who ultimately died, the most common of which was pregnancy (OR=0.15, CI=0.04-0.52). Radiological pneumonia was reported in 98% patients. Conclusion: Residing in urban area, delayed referral from general practitioner, presence of co-existing condition, especially pregnancy was responsible for mortality among influenza A (H1N1) infected positive

Remote sensing of D-region ionosphere using multimode tweeks

Lightning discharges radiate electromagnetic waves in a wide frequency range, with maximum energy in extremely low frequency/very low frequency band. A part of the radiated extremely low frequency/very low frequency wave energy is trapped in the Earth–ionosphere waveguide and travels thousands of kilometers in different modes with lower attenuation. Amplitude, frequency and phase of these waves are used to study the less explored D-region ionosphere at lower latitudes. Extremely low frequency/very low frequency observations are recorded continuously by automatic whistler detector setup installed at low-latitude Indian station Lucknow (Geom. lat. 17.6 ° N; long. 154.5 ° E). In total, 149 cases of tweeks having modes ranging from 3 to 6 have been recorded by automatic whistler detector during December 2010 and analyzed. Result shows that the propagation distance in the Earth–ionosphere waveguide lies between 1.1 and 9.4 Mm. The electron density in the lower D-region varies between 25 and 150 cm - 3 . The upper boundary of the waveguide varies between 80 and 95 km. The reported results are in good agreement with the earlier measurements at different latitudes and longitudes