Optimal Stratification of Univariate Populations via stratify R Package

Stratification reduces the variance of sample estimates for population parameters by creating homogeneous strata. Often, surveyors stratify the population using the most convenient variables such as age, sex, region, etc. Such convenient methods often do not produce internally homogeneous strata, hence, the precision of the estimates of the variables of interest could be further improved. This paper introduces an R-package called ’stratifyR’ whereby it proposes a method for optimal stratification of survey populations for a univariate study variable that follows a particular distribution estimated from a data set that is available to the surveyor. The stratification problem is formulated as a mathematical programming problem and solved by using a dynamic programming technique. Methods for several distributions such as uniform, weibull, gamma, normal, lognormal, exponential, right-triangular, cauchy and pareto are presented. The package is able to construct optimal stratification boundaries (OSB) and calculate optimal sample sizes (OSS) under Neyman allocation. Several examples, using simulated data, are presented to illustrate the stratified designs that can be constructed with the proposed methodology. Results reveal that the proposed method computes OSB that are precise and comparable to the established methods. All the calculations presented in this paper were carried out using the stratifyR package that will be made available on CRAN

HDL Implementation of Vending Machine by KCPSM3 Processor

The objective here to design vending machine controller which accepts money as input in any sequence and delivers the required product when the required amount has deposited and it also gives back the change. Here the additional facility is provided for our users. It is possible to withdraw the user deposited money in between if the customer wishes to pressing a specified button PUSH button. DOI: 10.17762/ijritcc2321-8169.15037

Combined effect of positioning and conventional respiratory physical therapy in complicated case of COVID-19: a case report

Many neurological and cardiovascular complications have been discovered post-COVID 19 infections. Long-term pulmonary complications like pneumonia, respiratory failure, ARDS, and lung abscess are described in different studies. To overcome these complications respiratory chest physiotherapy plays an important role for an individual. Respiratory chest physiotherapy has been shown to improve gas exchange, reverse pathological progression, and reduce or avoid the need for artificial ventilation when it is provided very early in other respiratory conditions. This case study highlights the combined effects of positioning with conventional Respiratory chest physiotherapy in post-COVID 19 respiratory complications in a 26-year-old young individual, presenting with complaints like dyspnoea. Changes in modified medical research council (MMRC) score and chest X-ray were seen by end of discharge of the patient

stratifyR: Optimal Stratification of Univariate Populations

This R package implements the stratification of univariate populations under stratified sampling designs using the method of Khan et al. (2002, 2008, 2015). It determines the Optimum Strata Boundaries (OSB) and Optimum Sample Sizes (OSS) for the study variable, y, using the best-fit frequency distribution of a survey variable (if data is available) or a hypothetical distribution (if data is not available). The method formulates the problem of determining the OSB as mathematical programming problem which is solved by using a dynamic programming technique. If a dataset of the population is available to the surveyor, the method estimates its best-fit distribution and determines the OSB and OSS under Neyman allocation directly. When the dataset is not available, stratification is made based on the assumption that the values of the study variable, y, are available as hypothetical realizations of proxy values of y from recent surveys. Thus, it requires certain distributional assumptions about the study variable. At present, it handles stratification for the populations where the study variable follows a continuous distribution, namely, Pareto, Triangular, Right-triangular, Weibull, Gamma, Exponential, Uniform, Normal, Log-normal and Cauchy distributions

Readiness and Perception of Pacific Students to Mobile Phones for Higher Education

The emergence and advancement of Information Communication Technologies have transformed facilitation and content delivery in higher education worldwide, the Pacific region being no exception. The extensive use of mobile phones in the Pacific, especially with the student-aged populace, is gradually creating a niche for mobile learning in the education landscape. However, there is a growing concern on the effectiveness of this innovative intervention keeping in mind the digital intelligence of Pacific students. This paper explores the readiness and perception of the Pacific students using mobile devices for learning. An online questionnaire was used to collect data for this exploratory research. While the results revealed the student’s willingness and positive perception to leverage on mobile phones for learning in higher education, their readiness for the mobile-driven education is rather dependent on various factors which are explored in detail. The paper concludes with recommendations for the higher education institutes and education ministries in the Pacific region

Optimal stratification in stratified designs using weibull - distributed auxiliary information

Sampling has evolved into a universally accepted approach for gathering information and data mining as it is widely accepted that a reasonably modest-sized sample can sufficiently characterize a much larger population. In stratified sampling designs, the whole population is divided into homogeneous strata in order to achieve higher precision in the estimation. This paper proposes an efficient method of constructing optimum stratum boundaries (OSB) and determining optimum sample size (OSS) for the survey variable. The survey variable may not be available in practice since the variable of interest is unavailable prior to conducting the survey. Thus, the method is based on the auxiliary variable which is usually readily available from past surveys. To illustrate the application as an example using a real data, the auxiliary variable considered for this problem follows Weibull distribution. The stratification problem is formulated as a Mathematical Programming Problem (MPP) that seeks minimization of the variance of the estimated population parameter under Neyman allocation. The solution procedure employs the dynamic programming technique, which results in substantial gains in the precision of the estimates of the population characteristics

Esters of petroselinic acid containing Trachyspermum copticum seed oil: Potential industrial lubricant base stocks

126-134Trachyspermum copticum seed oil contains volatile oil rich in thymol, which is distilled out and used for medicinal and aromatic formulations. The seed powder after removal of the volatiles loses its importance. However, the fixed oil being rich in unsaturation with petroselinic acid (18:1, Δ6; 68.3%) and linoleic acid (18:2; 25.3%) is used for preparing biolubricant base stocks. Methyl, isopropyl and 2-ethyl hexyl esters of the oil have been converted to epoxides, followed by in situ hydroxylation and acylation using hexanoic and butyric anhydrides. The acylated products have been evaluated for lubricant properties, and are found to exhibit density (0.91-0.97 g/cc); viscosity of 23.5-27.3 cSt at 40°C and 4.85-5.33 cSt at 100°C. The values are comparable to jatropha acylated products. The products exhibited good copper corrosion resistance value of ‘1a’ and high flash points of 230-242°C. The acylated esters with good weld load behavior, and lower wear and pour point values and viscosity indices, 128.84-138.94, can be potential base stocks belonging to group III category lubricants with ISO VG Grade about 22. These products can be further explored for the preparation of hydraulic, metal working and other industrial fluid formulations

Chronic alcohol exposure alters circulating insulin and ghrelin levels: role of ghrelin in hepatic steatosis

Fatty liver is the earliest response of the liver to excessive ethanol consumption. Central in the development of alcoholic steatosis is increased mobilization of nonesterified free fatty acids (NEFAs) to the liver from the adipose tissue. In this study, we hypothesized that ethanol-induced increase in ghrelin by impairing insulin secretion, could be responsible for the altered lipid metabolism observed in adipose and liver tissue. Male Wistar rats were fed for 5–8 wk with control or ethanol Lieber-DeCarli diet, followed by biochemical analyses in serum and liver tissues. In addition, in vitro studies were conducted on pancreatic islets isolated from experimental rats. We found that ethanol increased serum ghrelin and decreased serum insulin levels in both fed and fasting conditions. These results were corroborated by our observations of a significant accumulation of insulin in pancreatic islets of ethanol-fed rats, indicating that its secretion was impaired. Furthermore, ethanol-induced reduction in circulating insulin was associated with lower adipose weight and increased NEFA levels observed in these rats. Additionally, we found that increased concentration of serum ghrelin was due to increased synthesis and maturation in the stomach of the ethanol-fed rats. We also report that in addition to its effect on the pancreas, ghrelin can also directly act on hepatocytes via the ghrelin receptors and promote fat accumulation. In conclusion, alcohol-induced elevation of circulating ghrelin levels impairs insulin secretion. Consequently, reduced circulating insulin levels likely contribute to increased free fatty acid mobilization from adipose tissue to liver, thereby contributing to hepatic steatosis

Chronic alcohol exposure alters circulating insulin and ghrelin levels: role of ghrelin in hepatic steatosis

Fatty liver is the earliest response of the liver to excessive ethanol consumption. Central in the development of alcoholic steatosis is increased mobilization of nonesterified free fatty acids (NEFAs) to the liver from the adipose tissue. In this study, we hypothesized that ethanol-induced increase in ghrelin by impairing insulin secretion, could be responsible for the altered lipid metabolism observed in adipose and liver tissue. Male Wistar rats were fed for 5–8 wk with control or ethanol Lieber-DeCarli diet, followed by biochemical analyses in serum and liver tissues. In addition, in vitro studies were conducted on pancreatic islets isolated from experimental rats. We found that ethanol increased serum ghrelin and decreased serum insulin levels in both fed and fasting conditions. These results were corroborated by our observations of a significant accumulation of insulin in pancreatic islets of ethanol-fed rats, indicating that its secretion was impaired. Furthermore, ethanol-induced reduction in circulating insulin was associated with lower adipose weight and increased NEFA levels observed in these rats. Additionally, we found that increased concentration of serum ghrelin was due to increased synthesis and maturation in the stomach of the ethanol-fed rats. We also report that in addition to its effect on the pancreas, ghrelin can also directly act on hepatocytes via the ghrelin receptors and promote fat accumulation. In conclusion, alcohol-induced elevation of circulating ghrelin levels impairs insulin secretion. Consequently, reduced circulating insulin levels likely contribute to increased free fatty acid mobilization from adipose tissue to liver, thereby contributing to hepatic steatosis