Search

The aim of this study is to develop new exponential weighted moving average control charts based on a flexible model. These control charts created through least square and weighted least square estimators of the shape parameter of the new Kumaraswamy Pareto distribution. Exponential weighted moving average control charts based on least square and weighted least square estimators are compared for checking the performance of control charts. The results were not only explored through numerical values but also explored through half a dozen plots. The numerical results and plots exposed that the exponential weighted moving average control chart based on weighted least square estimator has better performance than the other proposed chart. Some key findings are discussed which are obtained from the comparative analysis of EWMA control charts. The simulation study of proposed charts is also reported in detail. The two data sets further demonstrate the effectiveness of the proposed charts. The reported results, for real data sets, are not only displayed in normal plots but also displayed in three-dimension plots. We recommend that the proposed method can be adapted for different types of distributions, and also suggest some future research directions. The concluding remarks are reported at the end of this manuscript. [ABSTRACT FROM AUTHOR]

Statistical process control basically involves inspecting a random sample of the output from a process and deciding whether the process is producing products with characteristics that fall within a predetermined range. It is used extensively in the field of reliability engineering. The reliability of the production process is thoroughly monitored for any internal variation using the SPC. The aim is always to settle such variations through a proper control monitoring. If the underlying distribution of the process is known to the researcher than the use of parametric control charts are useful but in many cases when there is doubt about the distribution of the process then it is preferred to use non parametric control charts. In this paper we propose the modified Exponentially weighted moving average (EWMA), Double Exponentially weighted moving average (DEWMA), Hybrid Exponentially weighted moving average (HEWMA), Extended Exponentially weighted moving average (EEWMA), Modified Exponentially weighted moving average (MEWMA) and mix- type control charts by mixing these control charts with Tukey control chart EWMA-TCC, DEWMA-TCC, HEWMA-TCC, EEWMA-TCC, MEWMA-TCC for the shape parameter of the Kumaraswamy Lehmann-2 Power function distribution (KL2PFD). [ABSTRACT FROM AUTHOR]

The reflected power function distribution (RPFD) has increasing importance in practical life due to its application in diversified fields of life. Organisations often face difficulty monitoring operations to identify and remove errors during production. That is why there is a need to introduce control charts that effectively monitor the processes, mainly when the number of errors follows RPFD and the manufacturing process is in control. The current study suggested memory-based control charts as a solution to the problem. The control charts are based on the estimation methods and play a remarkable role in enhancing the machine process reliability. The parameters of RPFD are evaluated through the percentile estimator (PE) and modified maximum likelihood estimator methods (MMLM). Further, we create memory-based control charts, i.e., hybrid exponentially weighted moving average (HEWMA) and extended exponentially weighted moving average (EEWMA), using the PE and MMLM. The findings reflect that HEWMA control charts based on PE provide a better result in estimating the defects. The implications of the study will be helpful for practitioners and policy makers from reliability engineering, management sciences, and statisticians. [ABSTRACT FROM AUTHOR]

In this research paper, we discuss the use of calibration technique to propose some new estimators under stratified sampling design and its use in reliability engineering. We first proposed the estimators using the calibration technique and then modify the already existing control charts such as Shewhart, exponentially weighted moving average and hybrid exponentially weighted moving averages using these calibration estimators. We also have studied the use of the proposed control charts in detail by showing their efficiency in terms of average run length. We find out that a hybrid control chart is more effective to detect the early shifts in the mean of the process. [ABSTRACT FROM AUTHOR]

In this paper, we develop attribute control charts (CCs) using two life data distributions named as Transmuted Power function distribution (TPFD) and Survival Weighted Power function distribution (SWPFD) under a time truncated life test (TTLT). The evaluation of the presented charts is based on the average run length and presented these evaluations in form of tables. The comparative study has been done for the suggested CCs in detail based on the criteria of average run length. We take up a real‐life situation assuming that the lifespan of the items under study follows the TPFD and SWPFD to assess the competence of the proposed idea. A simulation study is given to support our idea that the CCs based on SWPFD performs better as compare to control chart based on TPFD for monitoring of non‐conforming items. [ABSTRACT FROM AUTHOR]

As like the other countries, the risk of thyroid carcinoma is significantly increasing over the last few decades in Pakistan. This study aspires to know the cause and effect of this disease in urban and rural areas by investigation of different risk factors. For this purpose, incidence data was collected from Institute of Nuclear Medicine & Oncology Lahore and Sheikh Zayed Hospital, Lahore. This study consists of 88 rural and 232 urban patients and the possible risk factors of thyroid cancer investigated via questionnaire. The logistic regression is used as a statistical tool and the results are computed on the behalf of odd ratios. The result shows that 48 rural and 112 urban cases are suffered from thyroid cancer. In rural areas two factors use of iodine diet and oxidative stress are seen to be significant with odd ratios 1.642 and 1.796 while in the urban areas seven factors residential Area, oxidative Stress, too much consumption of meat & fast food, too much use of crucifer vegetables, excess use of fats and sea food are seen to be significant with odd ratios 0.760, 2.121, 1.294, 1.187, 1.618, 1.632 and 0.892, respectively. It is observed that the oxidative stress is the common factor in urban and rural areas. [ABSTRACT FROM AUTHOR]

Objectives: To assess the functional health literacy among adolescents of Model schools of Islamabad. To determine association between health literacy and health seeking behaviour of adolescents. Study Design: Cross sectional descriptive study. Place and duration of study: The study was conducted in Model schools of Islamabad, from Jan to Dec 2016. Material and Methods: Multi stage systematic sampling was done and a sample size of 350 using WHO sample size calculator. After taking informed consent from the students data were collected using the newest vital sign (NVS) for assessment of functional health literacy. Data were analyzed using SPSS version 22. Results: The mean age of the respondents was 15 (SD ± 0.6) years. There were 181 (52%) females and 169 (48%) males in the study. Out of 350 respondents 73 (20.9%) had very limited health literacy, while 187 (53.4%) had limited while 90 (25.7%) had adequate health literacy. In health seeking 30 students (8.6%) scored 1-2 on the health seeking behaviour score of 1-6 and therefore were categorized as having poor health seeking behaviour. While 164 students (46.9%) scored 3-4 and were categorized as having satisfactory health seeking. One hundred and fifty six students (44.6%) scored 4-5 and had good health seeking behaviour. Conclusion: The health literacy among the adolescents was limited and had no association with health seeking behaviour. [ABSTRACT FROM AUTHOR]

For the purpose to estimate the population mean, when the available population is structured as clusters, we have proposed the class of efficient estimators in this paper under two stage cluster sampling. In this paper we have also discussed the estimators when the weights of clusters are either known or unknown and also when the clusters are of equal sizes. The expressions mean square error (MSE) and equations have been derived for the proposed class of exponential estimators. Some theoretical conditions have been identified for which the proposed class of estimators is more efficient than Sukhatme et al. (1984) and Mishara (2012). An empirical study has also been carried out in order to demonstrate the performance of the proposed estimators. The proposed estimators are more efficient than usual call of estimators. [ABSTRACT FROM AUTHOR]

Koyuncu and Kadilar (2009) proposed a family of ratio-type estimators for population mean using auxiliary information in simple random sampling. Srivastava and Garg (2009) proposed a general class of ratio estimator for estimating population mean using auxiliary variablein two-stage sampling. In this paper, motivated by Srivastava and Garg (2009) and Koyuncu and Kadilar (2009) we have proposed a general class of estimators for population mean for three different cases in two-stage sampling design. The mean square error (MSE) and bias expressions have been obtained in a general form up to the first order of approximation for the three cases. It has also been shown that for each of the three cases in two-stage sampling, minimum MSE of this class is asymptotical equal to the MSE of regression estimator. An empirical study has also been carried out, in order to demonstrate the performance of proposed general class of estimators for three cases in two-stage sampling design. [ABSTRACT FROM AUTHOR]

The role of beta-glucosidase during the phototropic response in maize (Zea mays) coleoptiles was investigated. Unilateral blue light illumination abruptly up-regulated the activity of beta-glucosidase in the illuminated halves, 10 min after the onset of illumination, peaking after 30 min and decreasing thereafter. The level of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), which is released from DIMBOA glucoside (DIMBOA-Glc) by beta-glucosidase, and its degradation compound 6-methoxy-benzoxazolinone (MBOA) were elevated within 30 min in the illuminated halves as compare to the shaded halves, prior to the phototropic curvature. Furthermore, beta-glucosidase inhibitor treatment significantly decreased the phototropic curvature and decreased growth suppression in the illuminated sides. These results suggest that blue light induces the activity of beta-glucosidase in the illuminated halves of coleoptiles causing an increase in DIMBOA biosynthesis and the growth inhibition that leads to a phototropic curvature.