A new behavioural model for fertility schedules

Modelling age-specific fertility rates is of great importance in demography because of their influence on population growth. Although we have a variety of fertility models in the demographic literature, most of them do not have any demographic interpretation for their parameters. It is generally expected that models with behavioural interpretation are more universal than those without any interpretation. Even though the famous Gompertz model has some behavioural interpretation it suffers from other drawbacks. In the present work, we propose a new fertility model, which has its genesis in the generalization of logistic law. The proposed model has good behavioural interpretation, alongside having nice parameter interpretations.     

DIRECTIVE AND NONDIRECTIVE SPOUSAL SUPPORT: DIFFERENTIAL EFFECTS?

In this study we investigated whether the following factors influenced married partners' reactions to spousal support: type of support (directive vs. nondirective); individual differences (gender, depressive symptoms); and dimension along which support was evaluated (level of helpfulness vs. valence of emotional impact). Nondirective support was consistently rated more favorably on the dimension of partner's impact than on the dimension of partner's helpfulness, and this effect was exaggerated for those self-reporting a high level of depressive symptoms. Nonetheless, directive support was provided more frequently than was nondirective support in this sample. Gender differences and complications introduced by partner dysphoria suggest some situations in which directive support may be particularly difficult to provide effectively. Implications for couple therapy are discussed.     

Change point analysis of a Gaussian model

In this paper, the testing and estimation of a single change point in means and variances of a sequence of independent Gaussian normal random variables are studied. The Schwarz Information Criterion, SIC, is used to search for the change point. The unbiased version of the SIC for this change point problem is also derived for the finite sample case. Other properties of the SIC test statistic are given as well. Finally, two examples are given at the end of this paper to illustrate the method proposed, and changes are successfully detected.     

An advertising effect model

A model of advertising effects has been developed based on a distinction between “persuasion” advertising and “trigger” advertising. The former is designed to induce prospective purchasers to try the product and to establish a “product image”. The latter is aimed at “triggering” a purchase on the part of an individual whose image of the product has already been formed. The distinction has major implications for the type and timing of advertising. The model can be applied to determining an optimum distribution of advertising effort in the introduction of a new product, and the optimum advertising media mix.     

Children's Cognitive Perceptions of 6/49 Lottery Tickets

Recent studies have shown the high prevalence of youth gambling behavior. In particular, lottery ticket purchases among children and adolescents appear to be a highly preferred activity. Despite this fact, most research has focused on the underlying erroneous cognitions used by adults when selecting lottery tickets. This study examines the cognitive perceptions of children while engaged in selecting 6/49 lottery tickets. One hundred sixty-seven children (61 females; 106 males) from grades 3, 5, and 7 were asked to rank pre-selected 6/49 lottery tickets which were classified into a) long series, b) specific patterns, c) non equilibrated numbers, or d) perceived random selections. Children verbalized their rationale for selecting each ticket and were permitted to change the numbers on the lottery tickets they liked least in order to make them to more likely to be the winning ticket. Findings, in general, revealed small developmental differences in the types of underlying cognitive heuristics used by the children. The use of cognitive heuristics underlying the concept of randomness and the use of significant and meaningful numbers was observed to increase as children got older. Children between 9 and 11 were found to have employed the cluster heuristic more frequently than older children, ages 12–13. The results are interpreted in terms of the cognitive developmental changes in children's perceptions and the potential implication for gambling prevention programs are provided.     

A learning vector quantization neural network model for the classification of industrial construction projects

In several key functional areas of contemporary engineering and management science, neural networks have steadily been gaining recognition as robust and reliable tools for classification problems. This paper describes a new application of the learning vector quantization neural network: the classification of the degree of modularization appropriate for the construction of an industrial facility. This neural network uses variables related to plant location, labor issues, organizational issues, plant characteristics, project risks, and environmental issues as inputs to perform the classification. The neural network training and performance evaluation is also discussed.     

Time series analysis of out patients at Urban Health Centre, Suraj Kund, Meerut

Time series analysis of out-patients at Urban Health Centre, Suraj Kund, Meerut, was done using the out-patient attendance of last five years, with the aim to find out the values to help in coping up with the problem of health administration and management. The least square method and ratio-to-trend method were adopted for calculating the secular trend and seasonal variations respectively. There was an increasing trend in out-patients attendance indicating the increasing popularity of the Urban Health Centre. It was found that in second and third quarter of the year the out-patient attendance increased extraordinarily due to various reasons. The two more aspects of time series, i.e. cyclical trend and irregular flactuation could not be analysed due to their insignificant impact over the health management system.     

Workforce‐constrained Preventive Maintenance Scheduling Using Evolution Strategies

Heavy equipment overhaul facilities such as aircraft service centers and railroad yards face the challenge of minimizing the makespan for a set of preventive maintenance (PM) tasks, requiring single or multiple skills, within workforce availability constraints. In this paper, we examine the utility of evolution strategies to this problem. Comparison of the computational efforts of evolution strategies with exhaustive enumeration to reach optimal solutions for 60 small problems illustrates the ability of evolution strategies to yield optimal solutions increasingly efficiently with increasing problem size. A set of 852 large‐scale problems was solved using evolution strategies to examine the effects of task‐related problem characteristics, workforce‐related variables, and evolution strategies population size (μ) on CPU time. The results empirically supported practical utility of evolution strategies to solve large‐scale, complex preventive maintenance problems involving single‐ and multiple‐skilled workforce. Finally, comparison of evolution strategies and simulated annealing for the 852 experiments indicated much faster convergence to optimality with evolution strategies.     

Is Economic Policy Uncertainty Related to Suicide Rates? Evidence from the United States

The main objective of this paper was to see whether different countries around the world show differences in their sustainability levels as captured in the indicators from the Sustainable Society Index (SSI, Van de Kerk and Manuel in Ecol Econ 66:228–242, 2012) according to their level of income. To do so, the X-STATIS and CO-STATIS multivariate techniques were employed. With these methods, our sample of 151 countries and 21 indicators can be jointly represented along four time periods. The results obtained permit us to visualize that the groups of countries by income levels show differences in some of the variables from the SSI, because of the lack of proximities between those variables and the countries. Moreover, with the X-STATIS technique, the possible evolution of the countries or indicators over time can be represented, and with CO-STATIS, the relations between the social, economic and environmental aspects can be shown as well. From our results we were able to deduce that, on the one hand, social and economic indicators, such as Public Debt or Employment, are associated with countries having high and upper-middle incomes, for example, Chile, Israel, Malta, Kuwait, Saudi Arabia, Oman, Spain, Portugal, France, Poland and Czech Republic. On the other hand, countries with low and lower-middle incomes are more associated with environmental issues. Also, after finding that the differences between the countries by income levels are mainly caused by the economic indicators, we carried out two CO-STATIS analyses, one for social and economic variables, and the other for economic and environmental variables. These findings led us to deduce that, generally, the social and economic indicators are not related to each other, nor are the economic indicators related to the environmental ones. However, for some of the countries individually both relations may be possible.     

On classical and Bayesian order restricted inference for multiple exponential step stress model

In this article, we consider the multiple step stress model based on the cumulative exposure model assumption. Here, it is assumed that for a given stress level, the lifetime of the experimental units follows exponential distribution and the expected lifetime decreases as the stress level increases. We mainly focus on the order restricted inference of the unknown parameters of the lifetime distributions. First we consider the order restricted maximum likelihood estimators (MLEs) of the model parameters. It is well known that the order restricted MLEs cannot be obtained in explicit forms. We propose an algorithm that stops in finite number of steps and it provides the MLEs. We further consider the Bayes estimates and the associated credible intervals under the squared error loss function. Due to the absence of explicit form of the Bayes estimates, we propose to use the importance sampling technique to compute Bayes estimates. We provide an extensive simulation study in case of three stress levels mainly to see the performance of the proposed methods. Finally the analysis of one real data set has been provided for illustrative purposes.