Energy density in the diet of workers from São Paulo, Brazil, and associated socio-demographic factors*

Objective: This paper aims at analyzing the energy density (ED) of the diet of workers from the city of São Paulo, Southeastern Brazil, and the way this is associated with socio-demographic characteristics, as well as evaluating the relationship between ED and nutrient intake. Methods: A cross-sectional study evaluated the diet of 852 workers using the 24-hour dietary recall; one recall was applied to all individuals and a second one was applied to a sub-sample in order to adjust intrapersonal variability. The ED of the diet was calculated using three methods: inclusion of all solid foods and beverages, excluding water (ED 1); inclusion of all solid foods and beverages containing at least 5 kcal/100g (ED 2); and inclusion of all solid foods, excluding all beverages (ED 3). Linear regression was used to analyze the relationship between ED and socio-demographic variables and the relationship between ED and nutrients was evaluated using Pearson coefficient correlation. Results: Considering the workers' diet, the ED values observed were 1.18 kcal/g, 1.22 kcal/g and 1.73 kcal/g for the ED 1, ED 2, ED 3 methods, respectively. In the multiple regression models, only the age variable was maintained in the final model and showed an inverse association with all ED methods. ED 3 showed an increase in energy density for non-white individuals. Of all studied nutrients, protein was the only one that was not significantly correlated with ED 3 (p = 0.899). Conclusion: The young adults studied had a higher energy-density diet, representing a priority group for nutrition interventions. Regardless of the calculation method used, there is a correlation between ED and nutrients.Objetivo: Analisar a densidade energética (DE) da dieta de trabalhadores da cidade de São Paulo e sua associação com características sociodemográficas, bem como avaliar a relação entre DE e ingestão de nutrientes. Métodos: Estudo transversal que avaliou a dieta de 852 trabalhadores, por meio de recordatório de 24 horas, sendo um recordatório aplicado a todos os indivíduos e um segundo para subamostra, a fim de corrigir a variabilidade intrapessoal. A DE da dieta foi calculada por três métodos: inclusão de todos os alimentos sólidos e das bebidas, excluindo apenas água (DE 1); inclusão de todos os alimentos sólidos e bebidas calóricas que contêm, no mínimo, 5 kcal/100g (DE 2); inclusão de todos os alimentos sólidos e exclusão de todas as bebidas (DE 3). Para analisar a relação entre a DE e as variáveis sociodemográficas utilizou-se regressão linear, e a relação entre DE e nutrientes foi avaliada por meio do coeficiente de correlação de Pearson. Resultados: Para a dieta dos trabalhadores, os valores de DE observados foram 1,18 kcal/g, 1,22 kcal/g e 1,73 kcal/g, considerando-se os métodos DE 1, DE 2 e DE 3, respectivamente. Nos modelos múltiplos de regressão, apenas a variável idade apresentou associação negativa com todos os métodos de DE. Para a DE 3, houve incremento da DE para indivíduos não brancos. Dentre os nutrientes estudados, o único que não apresentou correlação significativa foi a proteína, para DE 3 (p = 0,899). Conclusão: Os adultos jovens tinham uma alimentação com maior DE, sendo um grupo prioriatário para intervenções nutricionais. Além disso, independente do método de cálculo, há correlação entre a DE e os nutrientes da dieta.Universidade de São Paulo Faculdade de Saude Publica Programa de Pos Graduacao em NutricaoUniversidade Federal de São Paulo (UNIFESP) Instituto de Saude e Sociedade Departamento de Saude, Clinica e InstituicoesUniversidade de São Paulo Faculdade de Saude Publica Departamento de NutricaoUNIFESP, Instituto de Saude e Sociedade Depto. de Saude, Clinica e InstituicoesSciEL

A Unified Tool for Performance Modelling and Prediction

Abstract. We describe a novel performability modelling approach which facilitates the efficient solution of performance models extracted from high-level descriptions of systems. The notation which we use for our high-level designs is the UML graphical modelling language. The technology which provides the efficient representation capability for the underlying performance model is the MTBDD-based PRISM probabilistic model checker. The UML models are compiled through an intermediate language, the stochastic process algebra PEPA, before translation into MTBDDs for solution. We illustrate our approach on a real-world analysis problem from the domain of mobile telephony. 1 Introduction Distributed, mobile and global computing environments provide robust development challenges to practising software system developers. Working with rapidlychanging implementation technology means that developers often must spend some of their development time finding and correcting errors in the software libraries and APIs which they use. Fortifying this difficulty is the arduous terrain of dynamic distributed systems where the difficulty of replaying a communication sequence which led to a system fault confounds the process of detecting and correcting implementation errors. In this setting, application developers rarely wish to expend the investment of time which would be needed to build and analyse a performance model of the system which they are developing. The concepts and the modelling languages of performance analysis are relatively unfamiliar to software developers and when already faced with a generous range of other difficulties in the development process, early predictive performance analysis can easily be overlooked

Petri Net Model of a Resource Management System for a Multi-Robot Assembly Cell

NRC publication: Ye

Distributed Control for a Task-Level Programmable Multi-Arm Robotic Assembly Cell

NRC publication: Ye

Communicating State-Machine Model of Resource Management in a Multi-Robot Assembly Cell

NRC publication: Ye

Performance analysis of uml models using aspect-oriented modeling techniques, in

Abstract. Aspect-Oriented Modeling (AOM) techniques allow software designers to isolate and address separately solutions for crosscutting concerns (such as security, reliability, new functional features, etc.) This paper proposes an approach for analyzing the performance effects of a given aspect on the overall system performance, after the composition of the aspect model with the primary model of a system. Performance analysis of UML models is enabled by the "UML Performance Profile for Schedulability, Performance and Time" (SPT) standardized by OMG, which defines a set of quantitative performance annotations to be added to a UML model. The first step of the proposed approach is to add performance annotations to both the primary model and to the aspect model(s). An aspect model is generic at first, and therefore its performance annotations must be parameterized. A generic model will be converted into a context-specific aspect model with concrete values assigned to its performance annotations. The latter is composed with the primary model, generating a complete annotated UML model. By using existing techniques, the complete model is transformed automatically into a Layered Queueing Network (LQN) performance model, which can be analyzed with existing solvers. The proposed approach is illustrated with a case study system, whose primary model is enhanced with some security features by using AOM. The LQN model of the primary system was validated against measurements in previous work. The performance effects of the security aspect under consideration are analyzed in two design alternatives by using the LQN model of the composed sy stem. 1