The Synthetic Control Chart Based on Two Sample Variances for Monitoring the Covariance Matrix

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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.

Indicadores da resposta ao estresse agudo associados com a familiaridade ao ambiente e aos procedimentos de banho e tosa em cães (Canis familiaris) da raça poodle

The stress responses can be parameters used in order to identify the welfare of animals. Behavior parameters can also be regarded as means to identify their relation to stressing situations. In this study, adult male and female poodle dogs, accustomed (group 1) or not (group 2) to the environment of a bath and grooming salon were analyzed through the plasmatic concentration of cortisol, cell counting of the immune system (total leukocytes and percentage of neutrophils and lymphocytes) and through observation of changes in behavior before and after the bath and grooming service. After arriving at the kennel, the dogs were taken to the bath and grooming facility, where they had their blood samples taken and were observed for ten minutes. The subsequent procedures consisted of the bath and grooming services and the collection of another blood samples. The research results were analyzed through non-parametric statistic tests and p < 0.05. Accustomed and non-accustomed dogs presented different hormonal and behavior responses: accustomed dogs presented an increasing of the cortisol level at the second blood samples collection, thus indicating stress towards the aforementioned procedures and presenting behavior responses which can be described as moderated stress. Non-accustomed dogs presented the same cortisol levels in both first and second samples suggesting that they were already reacting to the new environment. Dogs also shown behavioral responses which can be described as acute stress. Both male and female dogs showed similar immunological changes as well as different endocrine and behavioral profiles. Concerning aggression, this study demonstrates that biting the owner can be a predicting behavior of aggression during the bath and grooming service, male dogs were more aggressive than the female, and that males were more reactive to unknown caretaker. The results of this research propose that the familiarization of the animal with the bath and grooming environment and caretaker is important to the welfare of poodle dogs, especially to that of male dogs

Álcool e sociabilidade: a farra das adolescentes

The experience as a school psychologist allowed me to notice that expressions like I was like trash in the gang s barbecue , and we chatted away, only the girls, and we all got drunk , are very common in conversations between Elementary and High School students, pointing out to a concerning incidence of alcohol consumption among female adolescents. However, studies about this theme haven t gone deep in the nowadays reality these girls are living in. This study aimed at comprehending the aspects of the relation between girls and alcohol, starting from the point that exaggerated consumption indicates introductory rituals for some groups, making social relations easier and becoming a sociability factor. To give this study some support, a questionnaire was applied to 1028 female teenagers, between 12 and 18 years old, students in private schools in Natal, capital of Rio Grande do Norte. The context chosen for the development of the study - private schools -, arose from the notion that the majority of the data collection carried out about alcohol and other psychotropic drugs aim at public school students. The instrument used was divided in two parts, one that treated about the first contact with alcohol (experimentation), and other that points to the current relation with alcoholic beverages, with 27 closed questions but nevertheless with available space for manifestation like if other; which?, applied collectively in classrooms. The data received a statistic treatment from SPSS and showed that the first contact with alcoholic beverage happens in domestic environment, having parents and friends as companions, very precociously, around 10 years of age, as curiosity. At this moment, Ice drink is the most consumed beverage. The main reason that leads them to drink is to pass the time in parties, and they don t drink alone (93% of students researched), what gives alcohol this recreational and socializing characteristic. They do consider alcohol a kind of drug, but are not afraid of getting addicted. People that drink usually show to be extroverted, they get happier (40,3%) and are not shy at all (29,4%), have attitudes of moral character, like to get involved with unknown boys (18,5%), get numb (9,9%), or get sad (1,9%). They label as vulgar the girls that drink, depending on the amount, and to be stimulated by the boys to drink. The study shows that systematic interventions of the school are necessary, once it is an institution that should care about education and personality traits of children and adolescents, as well as the important role of the psychologist in this context. Besides, it claims the society to get effectively involved with the public policies that already exist

O significado do trabalho entre os jovens na transição de estudante universitário a profissional

The present study analyses the variability of the meaning of the work among young people on the transition from university to professional life, divided according to: university levels, knowledge area and graduation course. A hundred seventeen young people answered the questionaries structured on the components of the meaning of work. Semi-structured interviews were also made with parts of the sample about the themes related to the meaning of work on this way the information of the questionaries became complete. The answers of the interviews were studied through the analysis of the thematic contents. The results of such analysis and the answers of the questionaries were registered on the data base SPSS for Windows. The results of the statistic analysis made indicated that: (1) the centrality of work and the articulations among stronger spheres do not present variability according to level, area or course; (2) the course makes more difference values factors and descriptives factors than area and level; (3) the hierarchy of values presents variability according to area and the descriptive hierarchy presents variability according to course; (4) the level makes more difference specific attributes of the meaning of the work than area and course; (5) the standards of the meaning of work do not present variability according to level, area and course, but present variability according to type of the work market evaluation and planning the future work. In summary, the meaning of work present variability according to level, area and course of the young people, when studied in facets, except for the work centrality

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

Relação entre habilidades auditivas e fonológicas em crianças com dislexia do desenvolvimento

A dislexia do desenvolvimento, dificuldade específica de leitura, é caracterizada pela dificuldade em realizar a decodificação fono-grafêmica e percepção de fonemas acusticamente semelhantes. Este estudo teve como objetivo caracterizar o desempenho de crianças com dislexia quanto às habilidades auditivas e de consciência fonológica, correlacionando-as. Participaram deste estudo crianças com dislexia e com bom desempenho escolar, submetidas a avaliações audiológica, do processamento auditivo e das habilidades fonológicas. Os resultados indicaram diferença estatisticamente significante entre as habilidades auditivas de seqüência para sons verbais, mensagem competitiva ipsi e contra-lateral, dicótico de dígitos e dissílabos alternados e ainda nos subtestes de síntese, segmentação, manipulação e transposição. Os achados deste estudo evidenciaram correlação entre provas de memória auditiva e manipulação silábica e fonêmica e associação entre habilidades auditivas e fonológicas, sugerindo que os processos auditivos interferem diretamente na percepção de aspectos acústicos, temporais e seqüenciais dos sons para formação de uma representação fonológica estável.

Histopathological evaluation of treatment with chondroitin sulphate for osteoarthritis induced by continuous immobilization in rabbits

The aim of this study was to evaluate histologically the action of chondroitin sulphate in osteoarthritis experimentally induced by continuous immobilization. Fourteen young female Norfolk rabbits aged 2.5-3 months at the beginning of the experiment were divided into two equitable groups submitted to immobilization of the right knee for a period of 12 weeks. The treated group received 1.0 ml/animal/s.c. of 12% chondroitin sulphate, once a week for 12 weeks, and the untreated group did not receive any treatment. Two additional animals were not submitted to knee immobilization (sham group). Microscopical examination of knee preparations stained with haematoxylin-eosin and Masson trichrome showed lesions of both joints in treated and untreated groups, with no significant difference between the scores obtained for the right and left knees. Examination of preparations stained with picrosirius red showed collagen fibre alignment and misalignment in the right and left knees of the animals of all groups, but statistic analysis could not be performed. It was not possible to differentiate the proteoglycan concentration between limbs or groups (treated and untreated) by safrtanin O or toluidine blue staining. It was possible to conclude that the chondroitin sulphate was not able to reduce the histological changes induced by this osteoarthritis experimental model.

Accuracy of six minute walk test, stair test and spirometry using maximal oxygen uptake as gold standard

OBJETIVO: Determinar a acurácia das variáveis: tempo de escada (tTE), potência de escada (PTE), teste de caminhada (TC6) e volume expiratório forçado (VEF1) utilizando o consumo máximo de oxigênio (VO2máx) como padrão-ouro. MÉTODOS: Os testes foram realizados em 51 pacientes. O VEF1 foi obtido através da espirometria. O TC6 foi realizado em corredor plano de 120m. O TE foi realizado em escada de 6 lances obtendo-se tTE e PTE. O VO2máx foi obtido por ergoespirometria, utilizando o protocolo de Balke. Foram calculados a correlação linear de Pearson (r) e os valores de p, entre VO2máx e variáveis. Para o cálculo da acurácia, foram obtidos os pontos de corte, através da curva característica operacional (ROC). A estatística Kappa (k) foi utilizada para cálculo da concordância. RESULTADOS: Obteve-se as acurácias: tTE - 86%, TC6 - 80%, PTE - 71%, VEF1(L) - 67%, VEF1% - 63%. Para o tTE e TC6 combinados em paralelo, obteve-se sensibilidade de 93,5% e em série, especificidade de 96,4%. CONCLUSÃO: O tTE foi a variável que apresentou a melhor acurácia. Quando combinados o tTE e TC6 podem ter especificidade e sensibilidade próxima de 100%. Estes testes deveriam ser mais usados rotineiramente, especialmente quando a ergoespirometria para a medida de VO2máx não é disponível.

Diarréia em bezerros da raça Nelore criados extensivamente: estudo clínico e etiológico

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Parâmetros urbanísticos para habitação de interesse social: uma análise crítica para as Rocas em Natal/RN

Through the comparative critical analysis of the demanded urbanistic parameters in the legislation and of the urbanistic index found in the Rocas neighbourhood, having as study object the already consolidated constructions of residential use, intended to demonstrate that the neighbourhood needes specific norms and that the limits established for recognition of Special Areas of Social Interest for the urbanistic legislation of the City of Natal would have to be reviewed and to be brought up to date, once they show occupations like the ones of the reffered neighbourhood. At a first moment, bibliographical revision and elaboration of the theoretical referencial had been made, , to analyze afterwards the urbanistic legislation for the neibourhood of Rocas, that determines relative parameters for the sizes of land lots, coefficients of exploitation, minimum taxes of occupation and retreat. Through a field research in the area, a study on the occupation description was done at first, characterization of the neibourhood through the study of the social-economic aspects, of the existing infrastructure in the place, environmental aspects, morphologic and tipolgic analysis of the neibourhood as a whole. From the grouping of the found characteristics, sub-zones had been delimited, where the real object of study was detached to be analyzed. From the Sub-zoning, a statistic sampling was carried through with the intention to examine which of the urbanistic index is found in the dwellings of that already materialized place. This sampling, of one hundred and eighteen residences, was carried through by measurement of the lots and existing constructions in these places. Through this survey, for each habitacional unit, area of the lot, constructed area, retreats and coefficient of exploitation had been calculated. The comparison between the legislation parameters and the index found in the place reveal an expressive index of urbanistic irregularity and the necessity of special regulation for the Rocas neibourhood due to its specific social-space characteristic

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.

Testes de hipóteses em modelos de sobrevivência com Fração de cura

Survival models deals with the modeling of time to event data. However in some situations part of the population may be no longer subject to the event. Models that take this fact into account are called cure rate models. There are few studies about hypothesis tests in cure rate models. Recently a new test statistic, the gradient statistic, has been proposed. It shares the same asymptotic properties with the classic large sample tests, the likelihood ratio, score and Wald tests. Some simulation studies have been carried out to explore the behavior of the gradient statistic in fi nite samples and compare it with the classic statistics in diff erent models. The main objective of this work is to study and compare the performance of gradient test and likelihood ratio test in cure rate models. We first describe the models and present the main asymptotic properties of the tests. We perform a simulation study based on the promotion time model with Weibull distribution to assess the performance of the tests in finite samples. An application is presented to illustrate the studied concepts