The effects of early first sexual intercourse amongst Lesotho women: evidence from the 2009 Lesotho Demographic and Health Survey

Age at first sexual intercourse may be a predictor of future sexual behaviour and an important indicator for exposure to HIV transmission. The purpose of the study is to establish risk factors associated with age at first intercourse among Lesotho women aged 15 to 49 years. The data used came from the 2009 Lesotho Demographic and Health Survey and probit models were applied for analysis. It was found that women who have had their first sexual intercourse at age 16 or below were at risk of being married at age 18 or below (p < 0.001), are likely not to make it to secondary school (p < 0.001) and having the highest chance of not have known about the AIDS disease as compared to women who have had their sexual intercourse after the age of 16 years (p < 0.05). Delaying entry into sexuality could be safer and more secure to protect the sexual and reproductive health in young women. The more time women spend at school the less likely that they can engage in sexual intercourse at a young age (Afr. J Reprod Health 2016; 20[2]: 34-42).Keywords: Sexual intercourse, sexual debut, risk factor, HIV, AID

FOOD CONSUMPTION AND PRODUCTION IN TEMPE LAKE, SOUTH SULAWESI, INDONESIA

Challenges in providing sufficient food is a society problem and it will exist along with human civilization history.In this modern civilization, when the population reach more than 7 million people in the world, food consumption and production become a civilization problem and nature becomes a victim of it. Nowadays, almost 1 million people facing undernutrition and malnutritionThis study aimed to identify the pattern of food consumption and production in Tempe Lake, the biggest lake in the province or in Sulawesi island. A fieldwork conducted on February 2016 at Laelo Village (Kelurahan Laelo) that belongs to Tempe Sub-district (Kecamatan Tempe).  Total respondents in this study were 72 people who were selected randomly from those have use the lake as main source of livelihood. Some informants who know more about the lake were also interviewed. Data gathered mainly about  land use of the lake during dry season and wet (flood) season, and food consumption and production pattern, This research found that fish production of the lake has decreased significantly in the last 20 years due to sedimentation, overfishing and environmental contamination.   People consumed various foods for their dietary but mostly consuming rice that they purchased from market and fish and vegetables from the lake. There was no different in amount of rice and fish consumed during wet and dry season

Nonparametric precedence chart with repetitive sampling

DATA AVAILABILITY STATEMENT : The data that support the findings of this study are openly available in Taylor & Francis at https://doi.org/10.1080/0740817X.2015.1056861, reference number 10.1080/0740817X.2015.1056861.In most real-world applications, such as production and manufacturing processes, the underlying process distribution does not always follow a normal distribution. In such cases, statistical process control literature recommends the use of nonparametric (or distribution-free) control charts. This paper introduces a new distribution-free precedence chart using repetitive sampling. The performance of the proposed chart is investigated in terms of the average run-length (ARL) profile. The expressions of the in-control process probability and ARL of the proposed chart are introduced using integral formulas. The out-of-control performance of the new chart is compared to that of the existing precedence charts with and without runs-rules. A numerical example is provided using real-life data to demonstrate the application and implementation of the new chart.https://onlinelibrary.wiley.com/journal/20491573am2024StatisticsNon

Univariate and multivariate linear profiles using max type extended exponentially weighted moving average schemes

Many studies have shown that industrial as well as non-industrial business organizations present a growing need of robust and more efficient multivariate monitoring schemes in order to be able to monitor several quality characteristics simultaneous. To monitor two or more parameters simultaneously, several monitoring schemes are used concurrently in most of the cases instead of using a single scheme. Thus, in this paper, the exponentially weighted moving average (EWMA), double EWMA (DEWMA) and the recent triple EWMA (TEWMA) procedures are used to develop new single univariate and multivariate Max-type monitoring schemes for linear profiles under the assumptions of fixed and random linear models to monitor the regression parameters and variance error simultaneously. It is observed that the newly proposed schemes are better alternatives of the classical univariate and multivariate EWMA, DEWMA and TEWMA schemes for linear profiles in terms of the average run-length (ARL) and expected ARL profiles. Numerical examples are presented using simulated and real-life data.https://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=6287639Statistic

New extended distribution-free homogenously weighted monitoring schemes for monitoring abrupt shifts in the location parameter

A homogeneously weighted moving average (HWMA) monitoring scheme is a recently proposed memory-type scheme that gained its popularity because of its simplicity and superiority over the exponentially weighted moving average (EWMA) and cumulative sum (CUSUM) schemes in detecting small disturbances in the process. Most of the existing HWMA schemes are designed based on the assumption of normality. It is well-known that the performance of such monitoring schemes degrades significantly when this assumption is violated. Therefore, in this paper, three distribution-free monitoring schemes are developed based on the Wilcoxon rank-sum W statistic. First, the HWMA W scheme is introduced. Secondly, the double HWMA (DHWMA) W scheme is proposed to improve the ability of the HWMA W scheme in detecting very small disturbances in the location parameter and at last, the hybrid HWMA (HHWMA) W scheme is also proposed because of its flexibility and better performance in detecting shifts of different sizes. The zero-state performances of the proposed schemes are investigated using the characteristics of the run-length distribution. The proposed schemes outperform their existing competitors, i.e. EWMA, CUSUM and DEWMA W schemes, in many situations, and particularly the HHWMA W scheme is superior to these competitors regardless of the size of the shift in the location parameter. Real-life data are used to illustrate the implementation and application of the new monitoring schemes.DATA AVAILABILITY STATEMENT : The data used for the illustration example are available from Mukherjee et al. (2019) (10.1016/j.cie.2019.106059).SUPPLEMENTARY MATERIAL : S1 Appendix. Properties of the HWMA W scheme. https://doi.org/10.1371/journal.pone.0261217.s001S2 Appendix. Properties of the DHWMA W scheme. https://doi.org/10.1371/journal.pone.0261217.s002S3 Appendix. Properties of the HHWMA W chart.http://www.plosone.orgdm2022Statistic

Shewhart control schemes with supplementary 2‐of‐(h + 1) side‐sensitive runs‐rules under the Burr‐type XII distribution

Please read abstract in the article.http://wileyonlinelibrary.com/journal/qre2019-09-27hj2018Science, Mathematics and Technology Educatio

Distribution-free Phase II Mann-Whitney control charts with runs-rules

The addition of runs-rules has been recommended to improve the performance of classical, normal theory Shewhart-type control charts, for detecting small to moderate size shifts. In this paper, we consider adding both standard and improved runs-rules to enhance the performance of the distribution-free Phase II Shewhart-type chart based on the well-known Mann-Whitney statistic proposed by Chakraborti and Van de Wiel [1]. Standard runs-rules are typically of the form w-of-(w+v) with w > 1 and v 0 and the improved runs-rules scheme is a combination of the classical 1-of-1 runs-rule and the w-of-(w+v) runs-rules. The improved scheme improves the performance of the charts in detecting larger shifts while maintaining its performance in detecting small to moderate shifts. The in-control and out-of-control performance of the proposed runs-rules enhanced distribution-free charts are examined through extensive simulations. It is seen that the proposed charts have attractive performance compared to some competing charts, and are better in many cases. An illustrative example is provided, along with a summary and conclusions.The research of the third author was partly supported by a National Research Foundation grant (Reference: TTK14061168807,UID: 94102).http://link.springer.com/journal/1702017-09-30hb2016Statistic

A Bayesian ARMA-GARCH EWMA monitoring scheme for long run : a case study on monitoring the USD/ZAR exchange rate

Statistical process monitoring (SPM) offers an important toolkit used to monitor the stability of a process to improve the quality of outputs and/or services. More often, the design of control charts requires the estimation of the probability density function that involves selecting a common distribution that facilitates the estimation of the process parameters. The Bayesian approach is one of the most efficient techniques used in such instances. It incorporates informative and non-informative priors, i.e., uses information on past data and charting structures, to estimate parameters more efficiently than classical approaches. Bayesian approaches reduce the total expected cost over a finite horizon or the long-run expected average cost. This paper introduces a new Bayesian exponentially weighted moving average (EWMA) monitoring scheme for long runs based on an ARMA-GARCH model. The properties of the new monitoring scheme are investigated in terms of the run-length distribution. A case study on monitoring the USD to ZAR exchange rate is provided using the proposed Bayesian ARMA-GARCH EWMA monitoring scheme.The South African National Research Foundation (NRF), UCDP and the Research Development Programme at the University of Pretoria, Department of Research and Innovation (DRI).https://www.tandfonline.com/loi/lqen202024-07-20hj2024StatisticsSDG-08:Decent work and economic growt

A new CUSUM control chart under uncertainty with applications in petroleum and meteorology

Please read abstract in the article.http://www.plosone.orgpm2022Statistic

The use of fast initial response features on the homogeneously weighted moving average chart with estimated parameters under the effect of measurement errors

Fast initial response (FIR) features are generally used to improve the sensitivity of memory-type control charts by shrinking time-varying control limits in the earlier stage of the monitoring regime. This paper incorporates FIR features to increase the sensitivity of the homogeneously weighted moving average (HWMA) monitoring schemes with and without measurement errors under constant as well as linearly increasing variance scenarios. The robustness and the performance of the HWMA monitoring schemes are investigated in terms of numerous run-length properties assuming that the underlying process parameters are known and unknown. It is found that the FIR features improves the performance of the HWMA monitoring scheme as compared to the standard no FIR feature HWMA scheme, and at the same time, it is observed that the simultaneous use of a recently proposed FIR feature and multiple measurements significantly reduces the negative effect of measurement errors. An illustrative example on the volume of milk in bottles is used to demonstrate a real-life application.https://wileyonlinelibrary.com/journal/qrehj2022Statistic