On the mean residual life of records

Suppose that a technical system is subject to shocks, e.g. peaks of voltages from a sequence of identically independent voltages having a lower limit value v>0$v>0$. We propose a new definition for the mean residual life of the records of the sequence and study its various properties.     

Effect of Sociocultural Context and Parenting Style on Scholastic Achievement among Iranian Adolescents

School grades, family demographics and responses to the parental authority questionnaire were assessed in 240 eighth‐grade students in the southern, central and northern parts of Tehran, Iran's capital. The result showed that poorer families with traditional values had more authoritarian attitudes toward parenting than richer families with more modern values. In contrast to the studies conducted in East Asian societies, the current study found that authoritative parenting was the style associated with the highest academic outcome. Tests of mediation and moderation effects showed that the relation between parenting style and academic outcome was independent of sociocultural context.     

The Assessment of Quality of Life in Transitional Neighborhoods

Quality of life (QoL) is being considered as one of the fundamental concepts in contemporary era. It tries to assess the level of general welfare of the communities. Urban transitional neighborhoods possess specific situation and as a result present distinctive QoL. The major objective of this study is to identify and measure the QoL dimensions in urban transitional neighborhoods using both objective and subjective indices pertaining to Darvazeshemiran neighborhood of Tehran. In order to accomplish this and gather needed data, 244 questionnaires were distributed among Darvazeshemiran’s residents. This study suggests that there exists low level of QoL in the study area. That is 64.3 % of the residents were dissatisfied with the prevailing level of QoL. This in turn is associated with the transitional nature of this neighborhood. The residents were strongly dissatisfied with regard to the environmental qualification as opposed to accessibility status. Furthermore, this study identified five objective factors respectively regarding QoL. There exists low correlation between subjective and objective dimensions. That demands simultaneous consideration of both objective and subjective dimensions. It is argued that individual treatments of each could not accurately represent the QoL of residents.     

Designing an economically optimal repetitive group-sampling plan based on loss functions

Acceptance sampling is a quality assurance tool, which provides a rule for the producer and the consumer to make acceptance or rejection decision about a lot. This paper attempts to develop a more efficient sampling plan, variables repetitive group sampling plan, based on the total loss to the producer and consumer. To design this model, two constraints are considered to satisfy the opposing priorities and requirements of the producer and the consumer by using Acceptable quality level (AQL) and Limiting quality level (LQL) points on operating characteristic (OC) curve. The objective function of this model is constructed based on the total expected loss. In order to illustrate the application of the proposed model, an example is presented. In addition, the effects of process parameters on the optimal solution and the total expected loss are studied by performing a sensitivity analysis. Finally, the efficiency of the proposed model is compared with the variables single sampling plan, the variables double sampling plan and the repetitive group sampling plan of Balamurali and Jun (2006) in terms of average sample number, total expected loss and its difference with ideal OC curve.     

Improved functional portmanteau tests

Functional time series is a popular method of forecasting in functional data analysis. The Box-Jenkins methodology for model building, with the aim of forecasting, includes three iterative steps of model identification, parameter estimation and diagnostic checking. Portmanteau tests are one of the most popular diagnostic checking tools. In particular, they are applied to find if the residuals of the fitted model are white noise. Gabrys and Kokoszka [Portmanteau test of independence for functional observations. J Am Stat Assoc. 2007;102(480):1338–1348.] proposed a portmanteau test of independence for functional observation based on Box and Pierce's statistic. Their statistic is too sensitive to the lag value, specially when the sample size is small. Here, two modifications of Gabrys and Kokoszka statistic are presented, which have superior properties in small samples. The efficiency of the modified statistics is demonstrated through a simulation study.     

Analyzing time–frequency relationship between oil price and exchange rate in Pakistan through wavelets

This study analyzed the time–frequency relationship between oil price and exchange rate for Pakistan by using measures of continuous wavelet such as wavelet power, cross-wavelet power, and cross-wavelet coherency (WTC). The results of cross-wavelet analysis indicated that covariance between oil price and exchange rate is unable to give clear-cut results, but both variables have been in phase and out phase (i.e. they are anti-cyclical and cyclical in nature) in some or other durations. However, results of squared wavelet coherence disclose that both variables are out of phase and real exchange rate was leading during the entire period studied, corresponding to the 10–15 months’ scale. These results are the unique contribution of the present study, which would have not been drawn if one would have utilized any other time series or frequency domain-based approach. This finding provides evidence of anti-cyclical relationship between oil price and real effective exchange rate; however, in most of the period studied, real exchange rate was leading and passing anti-cycle effects on oil price shocks which is the major contribution of the study.     

The matched pair sign test using bivariate ranked set sampling for different ranking based schemes

Bivariate rank set sample (BVRSS) matched pair sign test is introduced and investigated for different ranking based schemes. We show that this test is asymptotically more efficient and more powerful than its counterpart sign test based on a bivariate simple random sample (BVSRS) for different ranking schemes. The asymptotic null distribution and the efficiency of the test are derived. Pitman’s asymptotic relative efficiency is used to compare the asymptotic performance of the matched pair sign test using BVRSS versus using BVSRS in all ranking cases. For small sample sizes, the bootstrap method is used to estimate P-values. Numerical comparisons are used to gain insight about the efficiency of the BVRSS sign test compared to the BVSRS sign test. Our numerical and theoretical results indicate that using any ranking scheme of BVRSS for the matched pair sign test is more efficient than using BVSRS.     

Health Disorder of Climate Migrants in Khulna City: An Urban Slum Perspective

As the most vulnerable climatic region in the country, Khulna City is increasingly experiencing climate‐change‐induced urban problems. For instance, occupancy by climate migrants (delete the term “illegal migrant”), drainage congestion, water logging and reduced fresh water availability are all increasing problems. In the last decade, the population in the city increased by more than 20 per cent due to migration from nearby climate vulnerable districts. This study explores the health disorders of climate migrants occupying the urban slums and squats of the Khulna City area. This study found that these climate migrants settled in the urban slums and squats and, as such, they do not have access to urban amenities such as clean drinking water, hygiene services, and health facilities. This study noted that these displaced people are at increased risk of health issues from unhygienic and overcrowded living conditions and from water and sanitation problems. They often suffer from different waterborne diseases, under‐nutrition and micronutrient deficiencies. This study suggests that there is a need for better planning, preparation and training in Bangladesh to which migrants move, including better training in health and related services on how to recognize and respond to health problems that may be slow to manifest. Education and training also need to be provided for the migrants themselves, to help them adapt culturally and to enhance their skills and potential for employment.     

Social Protection Spending in Context of Structural and Institutional Performance: A Global Empirical Analysis

Social Indicators Research - An understanding about the dynamics of social protection spending is made in the context of structural and institutional performances. A dataset of 134 countries for...