Variable parameter and double sampling (X)over-bar charts in the presence of correlation: The Markov chain approach

The general assumption under which the (X) over bar chart is designed is that the process mean has a constant in-control value. However, there are situations in which the process mean wanders. When it wanders according to a first-order autoregressive (AR (1)) model, a complex approach involving Markov chains and integral equation methods is used to evaluate the properties of the (X) over bar chart. In this paper, we propose the use of a pure Markov chain approach to study the performance of the (X) over bar chart. The performance of the chat (X) over bar with variable parameters and the (X) over bar with double sampling are compared. (C) 2011 Elsevier B.V. All rights reserved.

Control charts for monitoring the mean vector and the covariance matrix of bivariate processes

In this article, we propose new control charts for monitoring the mean vector and the covariance matrix of bivariate processes. The traditional tools used for this purpose are the T (2) and the |S| charts. However, these charts have two drawbacks: (1) the T (2) and the |S| statistics are not easy to compute, and (2) after a signal, they do not distinguish the variable affected by the assignable cause. As an alternative to (1), we propose the MVMAX chart, which only requires the computation of sample means and sample variances. As an alternative to (2), we propose the joint use of two charts based on the non-central chi-square statistic (NCS statistic), named as the NCS charts. Once the NCS charts signal, the user can immediately identify the out-of-control variable. In general, the synthetic MVMAX chart is faster than the NCS charts and the joint T (2) and |S| charts in signaling processes disturbances.

Bivariate control charts with double sampling

In this article, we consider the T(2) chart with double sampling to control bivariate processes (BDS chart). During the first stage of the sampling, n(1) items of the sample are inspected and two quality characteristics (x; y) are measured. If the Hotelling statistic T(1)(2) for the mean vector of (x; y) is less than w, the sampling is interrupted. If the Hotelling statistic T(1)(2) is greater than CL(1), where CL(1) > w, the control chart signals an out-of-control condition. If w < T(1)(2) <= CL(1), the sampling goes on to the second stage, where the remaining n(2) items of the sample are inspected and T(2)(2) for the mean vector of the whole sample is computed. During the second stage of the sampling, the control chart signals an out-of-control condition when the statistic T(2)(2) is larger than CL(2). A comparative study shows that the BDS chart detects process disturbances faster than the standard bivariate T(2) chart and the adaptive bivariate T(2) charts with variable sample size and/or variable sampling interval.

The double sampling and the EWMA charts based on the sample variances

We propose a new statistic to control the covariance matrix of bivariate processes. This new statistic is based on the sample variances of the two quality characteristics, in short VMAX statistic. The points plotted on the chart correspond to the maximum of the values of these two variances. The reasons to consider the VMAX statistic instead of the generalized variance vertical bar S vertical bar is its faster detection of process changes and its better diagnostic feature; that is, with the VMAX statistic it is easier to identify the out-of-control variable. We study the double sampling (DS) and the exponentially weighted moving average (EWMA) charts based on the VMAX statistic. (C) 2008 Elsevier B.V. All rights reserved.

Produtividade fabril II - método para rápido aumento da produtividade fabril: redução de esperas dentro do ciclo da operação

O método para rápido aumento da produtividade fabril, aplicável principalmente à indústria brasileira de manufatura (17% do PIB), fundamenta-se exclusivamente na redução ou eliminação do tempo inativo do homem, da máquina e do material, que é a grande causa da ineficiência. O método exige a utilização de apenas cinco das mais simples, elementares e conhecidas técnicas e é aplicável às vinte situações mais freqüentes (objetos de estudo) na indústria de manufatura. Nossa experiência atesta que o método é capaz de aumentar a produtividade fabril em valor superior a 30%, em poucos meses e de forma perene (houve um caso de aumento de 160% em toda uma seção de usinagem de uma empresa multinacional). Sua aplicação e a implantação das medidas dele decorrentes são feitas com extrema facilidade e, por isto, os resultados surgem muito rapidamente. Atinge portanto seu objetivo: proporcionar aumento da produtividade fabril em curto espaço de tempo. Este artigo detalhará sete objetos de estudo (situações): 1.redução da espera da máquina durante as inspeções; 2.redução da espera do operário, abordando trabalho em equipe, produção em linha e operação com ajudante; e 3.redução da espera do operador de máquina, por meio da diminuição do tempo-máquina, do controle do tempo-máquina e da atribuição de outras atividades ao operador pela adoção da célula de manufatura.

Structural Health Monitoring in Smart Structures Through Time Series Analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variabilidade espacial de atributos da fertilidade de um Latossolo Vermelho Distroférrico sob Sistema Plantio Direto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da satisfação das usuárias sobre a atenção à saúde da mulher no Rio Grande do Norte

This work discusses the evaluation of the satisfaction of the users on the women health care focusing on the quality of the primary care in the State of Rio Grande do Norte-BR. The main objective of this research is evaluate the satisfaction of the users about the actions applied to women health in the primary health care in Rio Grande do Norte, observing the information available through the Programa de Melhoria do Acesso e da Qualidade da Atenção Básica (PMAQ-AB). The specific objectives are: the evaluation of aspects related to women health; the evaluation of the specific actions related to welcoming the pregnant and; the evaluation of the information related to the postpartum. This dissertation is characterized as an evaluative research made through a multicentric transversal study, using a quantitative approach, which is part of the External Evaluation of the PMAQ-AB in the State of Rio Grande do Norte, made by the Federal University of Rio Grande do Norte. Some secondary data of the interviews with the users who were in the Basic Health Units were used during the External Evaluation of the PMAQ-AB in Rio Grande do Norte. The sample was collected following these criteria: the users that were in the Basic Health Units to attend to any procedure; they must had used the services for at least one year; and they must had agreed to participate the research. The ones that were attending to the services for the first time and the ones that did not use the services for at least 12 months were excluded from the sample. To the data collection it was used a chart of variables/indicators with the following information to the analysis: Women Health Care, Specific Care of the Pregnant and Information about he postpartum. The descriptive analysis of the data were made through absolute and relative frequencies of the variables using the software Statistic Package for Social Sciences (SPSS) for Windows, version 22.0.0. The results show a positive picture of the satisfaction of the users about the actions of the primary healthcare in women health in the State of the Rio Grande do Norte. Another important analysis is the integration of the primary health care with other points of the Healthcare System aiming to reorient the Model of Healthcare as a starter of the access and quality of the services given to the users. Therefore, the evaluation of the satisfaction of the users in health care is essential among all the agents involved in the process of consolidation of the Unified Health System SUS. Also having the need of rethinking the professional practice, reorganizing the processes of work of the multiprofessional teams in health care, enabling financial resources, inputs and materials, planning and systematizing new actions of healthcare aiming to ensure a perfect health care to the people

Intraoperative lactate levels and postoperative complications of pediatric cardiac surgery

Objectives: Correlate arterial lactate levels during the intraoperative period of children undergoing cardiac surgery and the occurrence of complications in the postoperative period. Aim: Arterial lactate levels can indicate hypoperfusion states, serving as prognostic markers of morbidity and mortality in this population. Background: Anesthesia for cardiac pediatric surgery is frequently performed on patients with serious abnormal physiological conditions. During the intraoperative period, there are significant variations of blood volume, body temperature, plasma composition, and tissue blood flow, as well as the activation of inflammation, with important pathophysiological consequences. Methods/Materials: Chart data relating to the procedures and perioperative conditions of the patients were collected on a standardized form. Comparisons of arterial lactate values at the end of the intraoperative period of the patients that presented, or not, with postoperative complications and frequencies related to perioperative conditions were established by odds ratio and nonparametric univariate analysis. Results: After surgeries without cardiopulmonary bypass (CPB), higher levels of arterial lactate upon ICU admission were observed in patients who had renal complications (2.96 vs 1.31 mm) and those who died (2.93 vs 1.40 mm). For surgeries with CPB, the same association was observed for cardiovascular (2.90 mm x 2.06 mm), renal (3.34 vs 2.33 mm), respiratory (2.98 vs 2.12 mm) and hematological complications (2.99 vs 1.95 mm), and death (3.38 vs 2.40 mm). Conclusion: Elevated intraoperative arterial lactate levels are associated with a higher morbidity and mortality in low- and medium-risk procedures, with or without CPB, in pediatric cardiac surgery.

O consentimento informado: Qual o seu real valor na prática médica?

Trata-se de um artigo que comenta sobre a real importância do Termo de Consentimento Informado na prática médica. Este documento tem sido cada vez mais usado como uma prática defensiva, a fim de constituir provas para defesa de um eventual processo judicial de responsabilidade médica, desvirtuando assim a idéia original, que seria a de respeitar a autonomia do paciente e delimitar a responsabilidade médica. O documento tem como objetivo mostrar que o médico cumpriu com seu dever de informar. Seu grande valor reside nos casos onde existam riscos de danos irreversíveis ao paciente. Conclui-se, porém, que um prontuário bem elaborado onde se inclui o registro das informações que foram transmitidas, bem como o grau de participação dos pacientes e seus familiares nas decisões terapêuticas, também deve ter valor ético e jurídico semelhante do TCI.

O efeito da autocorrelação no desempenho do gráfico T2 de hotelling: caso bivariado

The chart of control of Hotelling T2 has been the main statistical device used in monitoring multivariate processes. Currently the technological development of control systems and automation enabled a high rate of collection of information of the production systems in very short time intervals, causing a dependency between the results of observations. This phenomenon known as auto correlation causes in the statistical control of the multivariate processes a high rate of false alarms, prejudicing in the chart performance. This entails the violation of the assumption of independence and normality of the distribution. In this thesis we considered not only the correlation between two variables, but also the dependence between observations of the same variable, that is, auto correlation. It was studied by simulation, the bi variate case and the effect of auto correlation on the performance of the T2 chart of Hotelling.

Grafico misto de controle da media com amostragem em dois estagios

This paper proposes a new control chart to monitor a process mean employing a combined npx-X control chart. Basically the procedure consists of splitting the sample of size n into two sub-samples n1 and n2 determined by an optimization search. The sampling occur in two-stages. In the first stage the units of the sub-sample n1 are evaluated by attributes and plotted in npx control chart. If this chart signs then units of second sub-sample are measured and the monitored statistic plotted in X control chart (second stage). If both control charts sign then the process is stopped for adjustment. The possibility of non-inspection in all n items may promote a reduction not only in the cost but also the time spent to examine the sampled items. Performances of the current proposal, individual X and npx control charts are compared. In this study the proposed procedure presents many competitive options for the X control chart for a sample size n and a shift from the target mean. The average time to sign (ATS) of the current proposal lower than the values calculated from an individual X control chart points out that the combined control chart is an efficient tool in monitoring process mean.

Função quadrática

In general, the study of quadratic functions is based on an excessive amount formulas, all content is approached without justification. Here is the quadratic function and its properties from problems involving quadratic equations and the technique of completing the square. Based on the definitions we will show that the graph of the quadratic function is the parabola and finished our studies finding that several properties of the function can be read from the simple observation of your chart. Thus, we built the whole matter justifying each step, abandoning the use of decorated formulas and valuing the reasoning

Phantom development for radiographic image optimization of chest, skull and pelvis examination for nonstandard patient

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prevalência de sobrepeso/obesidade em crianças e adolescentes com constipação crônica funcional

OBJETIVO: Avaliar a prevalência do sobrepeso/obesidade em um grupo de crianças com constipação crônica funcional. MÉTODOS: Estudo retrospectivo com 257 crianças de dois a 15 anos com constipação crônica funcional diagnosticada segundo critérios de Roma II, atendidas consecutivamente em clínica terciária de gastroenterologia pediátrica. Informações demográficas, clínicas, diagnósticas e antropométricas foram obtidas de prontuários. O índice de massa corporal (IMC) foi calculado e utilizou-se a referência do Centers for Disease Control para determinar o percentil de IMC para idade e gênero. Crianças com percentil de IMC>85 foram consideradas com sobrepeso/obesidade; as com percentis > 5 e <85 foram classificadas como eutróficas. RESULTADOS: Para as variáveis sociodemográficas e clínicas, não houve diferença estatisticamente significante entre os subgrupos sobrepeso/obesidade e eutrofia. A prevalência de crianças constipadas com sobrepeso/obesidade foi de 24,4%. A média dos percentis do subgrupo sobrepeso/obesidade foi 94,4±4,3; a das eutróficas foi 45,3±24,2. A prevalência de sobrepeso/obesidade foi similar em ambos os sexos e grupos etários (<7 anos e >7 anos). CONCLUSÕES: Os subgrupos dos eutróficos e sobrepeso/obesidade foram homogêneos nas características sociodemográficas e clínicas, sugerindo que tais variáveis não influenciaram na prevalência do excesso de peso. A prevalência estimada de sobrepeso/obesidade entre as crianças com constipação crônica funcional está dentro dos valores esperados para a população pediátrica brasileira.