Progressively censored variables sampling plans for two-parameter exponential distributions

Progressive censoring is quite useful in many practical situations where budget constraints are in place or there is a demand for rapid testing. Balasooriya & Saw (1998) present reliability sampling plans for the two-parameter exponential distribution, based on progressively censored samples. However, the operating characteristic (OC) curve derived in their paper does not depend on the sample size. This seems to be because, in their computations, they forget to consider the proportion of uncensored data, which also has an important influence on the subsequent developments. In consequence, their OC curve is only valid when there is no censoring. In this paper, some modifications are proposed. These are needed to obtain a proper design of the above sampling plan. Whenever at least two uncensored observations are available, the OC curve is derived in closed form and a procedure for determining progressively censored reliability sampling plans is also presented. Finally, the example considered by Balasooriya & Saw is used to illustrate the results developed in this paper for several censoring levels.     

A nonparametric symmetry test for absolutely continuous bivariate copulas

Based on the works by Klement and Mesiar (Comment Math Univ Carolinae 47:141–148, 2006) and Nelsen (Stat Pap 48:329–336, 2007) on maximal asymmetry of copulas, we define and study the concept of tri-symmetry and we propose a simple statistic to test symmetry of a bivariate copula, given a random sample of an absolutely continuous bivariate random vector. We also make a power comparison against some other well known nonparametric symmetry tests.     

A New Measure of Fit for Equations With Dichotomous Dependent Variables

The econometrics literature contains many alternative measures of goodness of fit, roughly analogous to R ², for use with equations with dichotomous dependent variables. There is, however, no consensus as to the measures' relative merits or about which ones should be reported in empirical work. This article proposes a new measure that possesses several useful properties that the other measures lack. The new measure may be interpreted intuitively in a similar way to R ² in the linear regression context.     

The past,present and future of policy modeling

We evaluate the past, present, and future of policy modeling from both qualitative and quantitative perspectives. We do this through an extensive review and analysis of papers published in the Journal of Policy Modeling between 1978 and 2018. Over the years the focus of the policy modeling literature (and the Journal) changed. The changes were in research topics, approaches, techniques, theories, methods, and analytical tools as required for the rigorous analysis of complex and dynamic economic phenomena in policy modeling.     

ASSESSING CHANGE IN FAMILY FUNCTIONING AS A RESULT OF TREATMENT: THE STRUCTURAL FAMILY SYSTEMS RATING SCALE (SFSR)

This article describes a theoretically based structural family assessment procedure designed for use in evaluating therapy outcome. The standardized procedure for eliciting family interaction consists of the administration of three family tasks. The family's interactional patterns on the tasks are evaluated along six dimensions of structural family functioning: Structure, Flexibility, Resonance, Developmental Stage, Identified Patienthood, and Conflict Resolution. A manual has been developed for standardizing ratings for research applications. The measure demonstrated good interrater and internal consistency reliability. Available evidence for the content, factor, and construct validity of the measure is presented. Clinical outcome research studies conducted with the measure provide evidence that the measure is sensitive to different types of structural family intervention modalities and that it discriminates between a structural family intervention versus a no treatment/wait list control condition as well as between a structural family intervention versus an individual psychotherapy treatment modality. Finally, the measure has been demonstrated to be nonreactive under both treatment and wait list conditions.     

Violence against bisexuals, gays and lesbians in Mexico City

An essential premise of this work is that three dominant ideologies explain oppression against BGL, as a result of a gender system: adhesion to gender stereotypes, androcentrism and heterosexism. Three hundred eighteen bisexual and gay males (BG) and 188 bisexual and lesbian females (BL) were surveyed. By means of a self-applied questionnaire, variables of interest were researched. The following trends were observed: an important number of men and women interviewed suffered violence in their childhood and adolescence because they defied gender stereotypes, and not because of their sexual orientation; BG males were more often victims of violence than BL females. Within the BG group, those who challenged gender stereotypes were more frequently attacked than those who did not; men were identified as aggressors more frequently than women; and in the BG group, gender stereotype transgression was associated with the perception of suffering violence in the future.     

What Types of Training Improve Learners’ Performances in Second Language Listening Comprehension?

This study investigates the impact of a high-level and a low-level process-based L2 comprehension training on L1 French students’ listening performances. These students (N = 108) of English, Spanish, and German came from five different classes. After a L2 comprehension pretest, the participants were divided into two experimental groups. During the experimental phase, the two groups listened to the same three documents in their respective L2. The first group undertook listening comprehension activities relying on low-level processes, while the second group undertook activities aiming at fostering their use of high-level processes. These second types of activities were based on the Metacognitive Awareness Listening Questionnaire (MALQ) (Vandergrift, Goh, Mareschal & Tafaghodatari, 2006). As hypothesized, less skilled listeners trained to automatize low-level processes, scored significantly higher on the comprehension posttest than on the pretest. However, the hypothesis that more skilled listeners trained to develop high-level listening processes, would score better on the posttest than on the pretest could not be verified. Nevertheless, we observed some tendencies showing that more skilled learners had drawn some benefits from the training. In our conclusion, we argue that the impact of a high-level and a low-level process-based L2 comprehension training strongly depends on learners’ initial levels.     

Modeling population density guided by land use-cover change model: a case study of Bogotá

Population and Environment - Population densities provide valuable spatial information to identify populations at risk, quantify mobility, and improve our understanding of future urban settlements....     

A Lean Six Sigma framework for the reduction of ship loading commercial time in the iron ore pelletising industry

Evidence suggests that specifically designed frameworks to implement Lean Six Sigma (LSS) projects to tackle particular problems are more effective than ‘generic’ versions. This paper proposes an implementation framework to effectively deploy LSS to improve a key operation and performance indicator, i.e. ship loading commercial time, of one of the largest world producer of iron ore. This article therefore contributes with a refined framework to effectively implement LSS, and documents its successful application and effectiveness within the context of the case organisation. The LSS framework and project contributed in helping the studied organisation to improve both the capability of its ship loading process and commercial time by more than 30%, resulting in operational savings in the range of $300,000 USD per year. The systematic nature of the framework proposed also helped the organisation to establish a standardised routine to improve its operations. Managerial implications exposing the challenges faced during the implementation of LSS are also discussed to serve as lessons learnt to be considered in other LSS projects. Managers and engineers incharge of improving operations and processes can benefit from this paper as it can be used as a guide to direct the conduction of LSS projects and the empirical application of its principles and tools.     

Lean and green in the transport and logistics sector – a case study of simultaneous deployment

The transport and logistics sector is of vital importance for the stimulation of trade and hence the economic development of nations. However, over the last few years, this sector has taken central stage in the green agenda due to the negative environmental effects derived from its operations. Several disciplines including operations research and sub-areas of supply chain management such as green supply chains, green logistics and reverse logistics have tried to address this problem. However, despite the work undertaken through these disciplines, theoretical or empirical research into the sequential or simultaneous deployment of the lean and green paradigms, particularly, in the road transport and logistics sector is limited. This paper presents a case study where both paradigms have been combined to improve the transport operations of a world leader logistics organisation in the metropolitan area of Monterrey, Mexico. To do this, a systematic methodology and a novel tool called Sustainable Transportation Value Stream Map (STVSM) were proposed. The results obtained from the case study indicate that the concurrent deployment of the green and lean paradigms through such methodology and the STVSM tool is an effective approach to improve both operational efficiency and environmental performance of road transport operations. The paper can be used as a guiding reference for transport and logistics organisations to undertake improvement projects similar to the one presented in this paper. Additionally, this research also intends to stimulate scholarly research into the application of lean and green paradigms in the transport and logistics sector to expand the limited research pursued in this area.