Gráfico de controle modificado para processos com estruturas complexas de autocorrelação

This work proposes a modified control chart incorporating concepts of time series analysis. Specifically, we considerer Gaussian mixed transition distribution (GMTD) models. The GMTD models are a more general class than the autorregressive (AR) family, in the sense that the autocorrelated processes may present flat stretches, bursts or outliers. In this scenario traditional Shewhart charts are no longer appropriate tools to monitoring such processes. Therefore, Vasilopoulos and Stamboulis (1978) proposed a modified version of those charts, considering proper control limits based on autocorrelated processes. In order to evaluate the efficiency of the proposed technique a comparison with a traditional Shewhart chart (which ignores the autocorrelation structure of the process), a AR(1) Shewhart control chart and a GMTD Shewhart control chart was made. An analytical expression for the process variance, as well as control limits were developed for a particular GMTD model. The ARL was used as a criteria to measure the efficiency of control charts. The comparison was made based on a series generated according to a GMTD model. The results point to the direction that the modified Shewhart GMTD charts have a better performance than the AR(1) Shewhart and the traditional Shewhart.

Controle on-line por atributos para o número de não-conformidades no item inspecionado com base em uma sequência de inspeção

This paper proposes a procedure to control on-line processes for attributes, using an Shewhart control chart with two control limits (warning limit and control limit) and will be based on a sequence of inspection (h). The inspection procedure is based on Taguchi et al. (1989), in which to inspect the item, if the number of non-conformities is higher than an upper control limit, the process needs to be stopped and some adjustment is required; and, if the last inspection h, from all items inspected present a number of non-conformities between the control limit and warning limit. The items inspected will suffer destructive inspection, being discarded after inspection. Properties of an ergodic Markov chain are used to get the expression of average cost per item and the aim was the determination of four optimized parameters: the sampling interval of the inspections (m); the constant W to draw the warning limit (W); the constant C to draw the control limit (C), where W £ C, and the length of sequence of inspections (h). Numerical examples illustrate the proposed procedure

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.

Ajuste preventivo versus ajuste corretivo no controle on-line de processo do número de não-conformidades num item inspecionado

In production lines, the entire process is bound to unexpected happenings which may cost losing the production quality. Thus, it means losses to the manufacturer. Identify such causes and remove them is the task of the processing management. The on-line control system consists of periodic inspection of every month produced item. Once any of those items is quali ed as not t, it is admitted that a change in the fraction of the items occurred, and then the process is stopped for adjustments. This work is an extension of Quinino & Ho (2010) and has as objective main to make the monitoramento in a process through the control on-line of quality for the number of non-conformities about the inspected item. The strategy of decision to verify if the process is under control, is directly associated to the limits of the graphic control of non-conformities of the process. A policy of preventive adjustments is incorporated in order to enlarge the conforming fraction of the process. With the help of the R software, a sensibility analysis of the proposed model is done showing in which situations it is most interesting to execute the preventive adjustment

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.

kit educacional para controle e supervisão aplicado a nível

PEREIRA, J. P. ; CASTRO, B. P. S. ; VALENTIM, R. A. M. . Kit Educacional para Controle e Supervisão Aplicado a Nível. Holos, Natal, v. 2, p. 68-72, 2009

Rede de controle em ambiente hospitalar: um protocolo multiciclos para automação hospitalar sobre IEEE 802.3 com IGMP Snooping

VALENTIM, R. A. M. ; MORAIS, A. H. F. ; SOUZA, V. S. V ; ARAUJO JUNIOR, H. B. ; BRANDAO, G. B. ; GUERREIRO, A. M. G. . Rede de Controle em Ambiente Hospitalar: um protocolo multiciclos para automação hospitalar sobre IEEE 802.3 com IGMP Snooping. Revista Ciência e Tecnologia, v. 11, p. 19, 2009

Utilizando a porta paralela para controle remoto de um dispositivo

VALENTIM, R. A. M.; NOGUEIRA, I. A.;ROCHA NETO, A. F. Utilizando a porta paralela para controle remoto de um dispositivo. Revista da FARN, Natal, v. 2, p. 103-114, 2002.

Uma arquitetura distribuída de hardware e software para controle de um robô móvel autônomo

BRITTO, Ricardo S.; MEDEIROS, Adelardo A. D.; ALSINA, Pablo J. Uma arquitetura distribuída de hardware e software para controle de um robô móvel autônomo. In: SIMPÓSIO BRASILEIRO DE AUTOMAÇÃO INTELIGENTE,8., 2007, Florianópolis. Anais... Florianópolis: SBAI, 2007.

Controle social do espaço público: uma análise do conselho turístico pólo costa das dunas

The managing Conselho of public politics constitute one of the main experiences of democracy in Brazil contemporary representing a conquest for construction of a democratic institutionalism. The historical newness consists of the intensification and the institutionalization of the dialogue between government and society - in public and plural canals - as condition for an allocation more efficient joust and of the public resources. In this context the present study it objectified to understand from readings of the performance of represented group of bencheses the dynamics of functioning of the Tourist Conselho Pólo Costa das Dunas while space of participation and social control. The bibliographical research contemplated diverse sources in order to compile knowledge of credential authors in the quarrel of inherent subjects to the civil society and the public sphere to the construction of the citizenship to the conception formation and dynamics of the social control through Conselho of public politics. A qualitative perspective the case study was adopted as research method and for attainment of the data interviews with the members of the Conselho had been carried through beyond consultation the referring documents the dynamics of functioning of the Conselho. The profiles capacities and limitations of the members of the Conselho had been identified constitution social and dynamic organization of functioning of the Conselho and the readings of the members of the Conselho concerning the power to decide instances and participation. The results had shown that the allotment of being able in the Conselho does not occur of equal form. The functions of coordination of the activities of the Conselho are assumed by the representatives of the public agencies. Level of qualification of council members also if presents as difficulty to development of activities of Conselho since the majority of the interviewed ones disclosed unreliability and unfamiliarity when thematic specific that runs away from its organizacional reality they are boarded in the assemblies. Of this form the Conselho if presents more as half of institutional legitimation of what half of characterization of the creation of a public sphere properly said. Finally he could himself be concluded that a democratic culture inexists that inside crosses practical the institutional ones of the Conselho thus limiting the possibility to reach the effective social control of the public politics of tourism in the Rio Grande do Norte

A ouvidoria pública como instrumento de controle das ações da Secretaria de Saúde do Pará

The State and Public Administration have gone through several reforms in search of a quick operation and the provision of services with quality. With the democratization of the country and the issue of the Constitution in 1988, further reform of the State and Public Administration, joined the government agenda in 1995 and included among its objectives, the principles of participation and social control. In view of this, it raises the Public Ombudsman in order to be a channel for the participation of users in the management of public affairs, social control, transparency of administrative actions, improving the quality of service and meeting the needs of the community. The aim of this study is to assess whether the Ombudsman of the State Department of Public Health to contribute to the period 2006-2008, for the improvement of specialized consulting services. The research is characterized as descriptive, qualitative approach. The collection technique used was the interview, conducted with 37 service users and two servants of the Ombudsman. The analysis was developed based on the perception of users and servers in the opinion of the Ombudsman. The most relevant results of the research showed that 41% of users search the Ombudsman because they believed that solve the problem presented. However, even with this level of public acceptance, the Ombudsman reached average index of resolvability of 53% in the period. In his role has not developed mechanisms for quality control of services, which is mentioned by 67% of users. It turned out the same fact in relation to popular participation, which is confirmed by 84% of users. For 24% of users, the problems raised were resolved, and of these, 56% believe that the Ombudsman has contributed to the positive outcome. As a result of the search results, it appears that the Ombudsman's SESPA / PA, is not fulfilling its role to ensuring the democratization of articipation in management, social control and has limited contribution to solving the problems of users and to improve the quality of services

Vigilância eletrônica no trabalho bancário: do controle consentido ao totalitarismo corporativo

This dissertation addresses the electronic surveillance theme in the banking context. The research that originated it, which was held in an organization called for the fiction name Banco Total, started from the following driving question: How do workers at a bank perceive electronic surveillance at their process of work? The research s main objective was to comprehend how workers perceive electronic surveillance at their process of work. The study adopted an interdisciplinary perspective, having Management as the original field, establishing a dialogue with others disciplines, like Philosophy and Sociology. About its methodology, it s a qualitative research that addressed its object in oral (interviews with live history elements) way. . Ten individuals were interviewed. The analytical process utilized the hermeneutical-dialectics technique.. From the analyses (hermeneutics) of the data, the following themes have emerged: (i) Acquiescence ; (ii) Monitoring; (iii) Time and Motion; (iv) Fear; (v) Interdiction; and (vi) Resistance . From the discussion (dialectic) of the results, this work presents three synthetic propositions that culminate in the following dimensions (i) control; (ii) acquiescence; (iii) corporative totalitarianism. It can be concluded that electronic surveillance is one mechanism of control emerged from the apply of technology at Total Bank; that information technology has been improving the control mechanisms of management theories; and that the imbrications between management and material technology control mechanisms at a context where there is acquiescence by workers contribute for the emergency of corporative totalitarianism components

Relações entre mecanismos de coordenação e controle com desempenho organizacional: um estudo nas instituições públicas de ensino médio de Natal

This research aimed at relating coordination and control forms to organizational performance. The multicase study was applied in two public high schools: Centro Federal de Educação Tecnológica do Rio Grande do Norte and Floriano Cavalcanti. In order to accomplish these objectives, it was developed a qualitative analysis and considered coordination and control forms of several authors. Also was considered Sander´s (1984) model of organizational performance. The mentioned model considers two criteria to analyze organizational performance: one instrumental (efficiency and efficacy) and other substantive (effectiveness e relevance). The research attempts to show the importance of balancing these criteria in a way that effectiveness and relevance becomes more important at schools. It was proven that the use of bureaucratic coordination forms has the power to influence the evaluation on the instrumental technique. At the same time, it was observed that the use of mechanisms based on the autonomy of the school is related to efficiency and efficacy. The object of this research can be considered successful

Avaliação de produtos naturais no controle de biofilmes formados em sistema dinâmico

The biofilms microbial forms of association are responsible for generating, accelerating and / or induce the process of corrosion. The damage generated in the petroleum industry for this type of corrosion is significatives, representing major investment for your control. The aim of this study was to evaluate such tests antibiograms the effects of extracts of Jatropha curcas and essential oil of Lippia gracilis Schauer on microrganisms isolated from water samples and, thereafter, select the most effective natural product for further evaluation of biofilms formed in dynamic system. Extracts of J. curcas were not efficient on the complete inhibition of microbial growth in tests type antibiogram, and essential oil of L. gracilis Schauer most effective and determined for the other tests. A standard concentration of essential oil of 20 μL was chosen and established for the evaluation of the biofilms and the rate of corrosion. The biocide effect was determined by microbial counts of five types of microorganisms: aerobic bacteria, precipitating iron, total anaerobic, sulphate reducers (BRS) and fungi. The rate of corrosion was measured by loss of mass. Molecular identification and scanning electron microscopy (SEM) were performed. The data showed reduction to zero of the most probable number (MPN) of bacteria precipitating iron and BRS from 115 and 113 minutes of contact, respectively. There was also inhibited in fungi, reducing to zero the rate of colony-forming units (CFU) from 74 minutes of exposure. However, for aerobic and anaerobic bacteria there was no significant difference in the time of exposure to the essential oil, remaining constant. The rate of corrosion was also influenced by the presence of oil. The essential oil of L. gracilis was shown to be potentially effective

Controle preditivo neural aplicado à processos petroquímicos

A pesquisa tem como objetivo desenvolver uma estrutura de controle preditivo neural, com o intuito de controlar um processo de pH, caracterizado por ser um sistema SISO (Single Input - Single Output). O controle de pH é um processo de grande importância na indústria petroquímica, onde se deseja manter constante o nível de acidez de um produto ou neutralizar o afluente de uma planta de tratamento de fluidos. O processo de controle de pH exige robustez do sistema de controle, pois este processo pode ter ganho estático e dinâmica nãolineares. O controlador preditivo neural envolve duas outras teorias para o seu desenvolvimento, a primeira referente ao controle preditivo e a outra a redes neurais artificiais (RNA s). Este controlador pode ser dividido em dois blocos, um responsável pela identificação e outro pelo o cálculo do sinal de controle. Para realizar a identificação neural é utilizada uma RNA com arquitetura feedforward multicamadas com aprendizagem baseada na metodologia da Propagação Retroativa do Erro (Error Back Propagation). A partir de dados de entrada e saída da planta é iniciado o treinamento offline da rede. Dessa forma, os pesos sinápticos são ajustados e a rede está apta para representar o sistema com a máxima precisão possível. O modelo neural gerado é usado para predizer as saídas futuras do sistema, com isso o otimizador calcula uma série de ações de controle, através da minimização de uma função objetivo quadrática, fazendo com que a saída do processo siga um sinal de referência desejado. Foram desenvolvidos dois aplicativos, ambos na plataforma Builder C++, o primeiro realiza a identificação, via redes neurais e o segundo é responsável pelo controle do processo. As ferramentas aqui implementadas e aplicadas são genéricas, ambas permitem a aplicação da estrutura de controle a qualquer novo processo