Analysis of the implementation of ergonomic design at the new units of an oil refinery

Ergonomic design is the adaptation of working conditions to human limitations and skills in the physical design phase of a new installation, a new working system, or new products or tools. Based on this concept, the purpose of this work was to analyze the implementation of ergonomic design at the new industrial units of an oil refinery, using the method of Ergonomic Workplace Assessment. This study was conducted by a multidisciplinary team composed of operation, maintenance and industrial safety technicians, ergonomists, designers and engineers. The analysis involved 6 production units, 1 industrial wastewater treatment unit, and 3 utilities units, all in the design detailing phase, for which 455 ergonomic requirements were identified. An analysis and characterization of the requirements identified for 5 of the production units, involving a total of 246 items, indicated that 62% were related to difficult access and blockage operations, while 15% were related to difficulties in the circulation of employees inside the units. Based on these data, it was found that the ergonomic requirements identified in the design detailing phase of an industrial unit involve physical ergonomics, and that it is very difficult to identify requirements related to organizational or cognitive ergonomics.     

Effects of strength and power training on neuromuscular variables in older adults

The purpose of this study was to compare the neuromuscular adaptations produced by strength-training (ST) and power-training (PT) regimens in older individuals. Participants were balanced by quadriceps cross-sectional area (CSA) and leg-press 1-repetition maximum and randomly assigned to an ST group (n = 14; 63.6 ± 4.0 yr, 79.7 ± 17.2 kg, and 163.9 ± 9.8 cm), a PT group (n = 16; 64.9 ± 3.9 yr, 63.9 ± 11.9 kg, and 157.4 ± 7.7 cm), or a control group (n = 13; 63.0 ± 4.0 yr, 67.2 ± 10.8 kg, and 159.8 ± 6.8 cm). ST and PT were equally effective in increasing (a) maximum dynamic and isometric strength (p < .05), (b) increasing quadriceps muscle CSA (p < .05), and (c) decreasing electrical mechanical delay of the vastus lateralis muscle (p < .05). There were no significant changes in neuromuscular activation after training. The novel finding of the current study is that PT seems to be an attractive alternative to regular ST to maintain and improve muscle mass.     

Assessing the Effectiveness of a Capacity Building Intervention in Empowering Hard-to-Reach Communities

ABSTRACT

This article focuses on hard-to-reach communities with weak histories of engagement and it explores whether facilitated community interventions can empower and develop community resilience. Drawing on data from 6 communities, the article indicates a need for tailored and context-specific support that matches local needs. Implementation of community projects is not linear and the delivery of interventions in hard-to-reach communities is associated with the risk of failure. Developing community resilience among communities that do not engage requires long-term interventions, on-going input, and a collaborative approach to working with communities to support equal and harmonized development.     

Bayesian inference for the Birnbaum–Saunders nonlinear regression model

We develop a Bayesian analysis for the class of Birnbaum–Saunders nonlinear regression models introduced by Lemonte and Cordeiro (Comput Stat Data Anal 53:4441–4452, 2009). This regression model, which is based on the Birnbaum–Saunders distribution (Birnbaum and Saunders in J Appl Probab 6:319–327, 1969a), has been used successfully to model fatigue failure times. We have considered a Bayesian analysis under a normal-gamma prior. Due to the complexity of the model, Markov chain Monte Carlo methods are used to develop a Bayesian procedure for the considered model. We describe tools for model determination, which include the conditional predictive ordinate, the logarithm of the pseudo-marginal likelihood and the pseudo-Bayes factor. Additionally, case deletion influence diagnostics is developed for the joint posterior distribution based on the Kullback–Leibler divergence. Two empirical applications are considered in order to illustrate the developed procedures.     

An extended Lomax distribution

A new five-parameter continuous distribution, the so-called McDonald Lomax distribution, that extends the Lomax distribution and some other distributions is proposed and studied. The model has as special sub-models new four- and three-parameter distributions. Various structural properties of the new distribution are derived, including expansions for the density function, explicit expressions for the moments, generating and quantile functions, mean deviations and Rényi entropy. The score function is derived and the estimation is performed by maximum likelihood. We also obtain the observed information matrix. An application illustrates the usefulness of the proposed model.     

Nonnull asymptotic distributions of the LR,Wald, score and gradient statistics in generalized linear models with dispersion covariates

The class of generalized linear models with dispersion covariates, which allows us to jointly model the mean and dispersion parameters, is a natural extension to the classical generalized linear models. In this paper, we derive the asymptotic expansions under a sequence of Pitman alternatives (up to order n ^?1/2) for the nonnull distribution functions of the likelihood ratio, Wald, Rao score and gradient statistics in this class of models. The asymptotic distributions of these statistics are obtained for testing a subset of regression parameters and for testing a subset of dispersion parameters. Based on these nonnull asymptotic expansions, the power of all four tests, which are equivalent to first order, are compared. Furthermore, we consider Monte Carlo simulations in order to compare the finite-sample performance of these tests in this class of models. We present two empirical applications to two real data sets for illustrative purposes.     

On the Marshall–Olkin extended distributions

ABSTRACT

A general method of introducing a new parameter to a well-established continuous baseline cumulative function G to obtain more flexible distributions was proposed by Marshall and Olkin (1997 Marshall, A.W., Olkin, I. (1997). A new method for adding a parameter to a family of distributions with application to the exponential and Weibull families. Biometrika 84:641–652.[Crossref], [Web of Science ®] , [Google Scholar]). This new family is known as Marshall–Olkin extended G family of distributions. In this article, we characterize this family as mixtures of the distributions of the minimum and maximum of random variables with cumulative function G. We demonstrate that the coefficients of the mixtures are probabilities of random variables with geometric distributions. Additionally, we present new representations for the density and cumulative functions of this class of distributions. Further, we introduce a new three-parameter continuous model for modeling rates and proportions based on the Marshall–Olkin's method. The model parameters are estimated by maximum likelihood and the observed information matrix is determined. The usefulness of the new model is illustrated by means of a real dataset.     

计算机辅助设计进行危险状况的仿真

本文旨在提出用计算机模拟反映如木器厂工作的危险性，小型企业关注未使用相对安全设备的工作场地，木器厂有许多潜在的危险情况如将木材从一个地方搬用到另一地方及高速旋转的车床可能对工人的直接伤害，这种危险状况可用虚拟现实进行仿真。     

Partners in life: Unmarried couples in Hungary

Non-marital cohabitation in Hungary is documented using data from the 1970 and 1980 censuses and the 1984 microcensus. Observed patterns contrast with those in several other countries, particularly those of western and northwestern Europe. Firstly, in Hungary unmarried couples or ‘partners in life’ are more common, and their proportion is increasing more rapidly, among the previously married than among the single. Secondly, both among the single and the previously married, mothers are more likely than childless women to be cohabiting. Thirdly, although proportions cohabiting are higher in urban than in rural areas, partners in life are concentrated among those with the lowest educational level.     

APPLICATION OF A PRODUCTIVITY MODEL FOR COMPUTER SYSTEMS*

The performance evaluation of computer systems as they impact on final user requirements for services is a complex task. A management-oriented approach to the issue based on conventional economic theory was described in a previous report as an outgrowth of a joint university-industry research project. In this sequel we report our experience in estimating, testing, and applying this conceptual model.