Made available in DSpace on 2017-07-10T19:23:37Z (GMT). No. of bitstreams: 1 Marcio.pdf: 2681229 bytes, checksum: ea2c2a858c1d63340b780fc26ee571c3 (MD5) Previous issue date: 2013-02-20 / Irrigated agriculture has great potential for productivity. The proof is that the area for irrigated agriculture in the world, representing approximately 20 % of the total area destined to agriculture, is responsible for approximately 45 % of the total harvested. In order to maximize the profits of agricultural products, it is necessary to comply with various protocols of good practice, which include, in addition to maintaining a quality standard specific to the products, reducing environmental impact and generating benefits to communities involved in the agricultural production. Then, it is possible to achieve a more profitable niche market. To achieve the agricultural products standards required by the market, there must be a level of control in the processes of cultural practices in the water and fertilizer application. Statistical quality control processes were implemented in the industries of Japan after the Second World War and it is considered the tool responsible for the triumph of manufacturing, service and quality processes for the country. Quality control is perfectly adaptable for the agricultural production system. Therefore, this research aimed to assess the distribution of water and fertilizer in a drip irrigation system and determine the limits of statistical process and process capabilities in irrigation and fertigation under different pressures and concentrations of NPK (Nitrogen, Phosphorus and Potassium). The experiment was conducted in the municipality of Salto do Lontra, in a farm that participates in the Family Irrigation Project developed by Unioeste University. There were four inlet pressures: 150, 200, 250, and 300 kPa, combined with three NPK solution concentrations: 0, 200, and 400 mgL-1. In the evaluations, two methods were used for sampling, one with 16 points and another with 32 points. Using the average flow rate, CUC and CUD were calculated both methodologies. The classification of CUC was "excellent" for all assessments. Using CUD, 83.4 % of ratings were "excellent" with the sampling methodology with 16 points, and 97.3 % with the methodology of 32 points. None of the processes were considered acceptable for process use, when statistical control limits were calculated. The processes of irrigation and fertigation more suitable for improvement and consequent process capability increase were those with inlet pressures of 150 and 200 kPa. / A agricultura irrigada tem um grande potencial de produtividade. Prova disso é que a área destinada à agricultura irrigada no mundo, correspondente a cerca de 20 % da área total para a agricultura, e é responsável por aproximadamente 45 % do total colhido. Visando maximizar os lucros dos produtos agrícolas, é necessário cumprir diversos protocolos de boas práticas, que incluem, além de manter um padrão de qualidade específico dos produtos, reduzir os impactos ambientais e gerar benefícios sociais à s comunidades envolvidas na produção agrícola. Feito isso, é possível atingir um nicho de mercado mais lucrativo. Para atingir os padrões dos produtos agrícolas exigidos pelo mercado, deve haver um controle nos processos de tratos culturais na aplicação de água e fertilizantes. O controle estatístico de qualidade de processos passou a ser utilizado nas indústrias do Japão após a segunda guerra mundial e é considerada a ferramenta responsável pelo triunfo na produção de produtos, serviços e processos de qualidade. O controle de qualidade é perfeitamente adaptável ao sistema de produção agrícola. Diante disso, a realização desta pesquisa teve por objetivo avaliar a distribuição de água e fertilizante num sistema de irrigação por gotejamento e determinar os limites estatísticos de processo e as capacidades de processo na irrigação e fertirrigação submetidos a diferentes pressões e concentrações da solução de NPK (nitrogênio, fósforo e potássio). O experimento foi desenvolvido no município de Salto do Lontra, em uma propriedade rural participante do Projeto de Irrigação Familiar da Unioeste. Foram utilizadas quatro pressões de entrada: 150, 200, 250 e 300 kPa, combinadas com três concentrações de solução NPK: 0, 200 e 400 mgL-1. Nas avaliações, foram utilizadas duas metodologias de amostragem, uma com 16 e outra com 32 pontos. Com os valores médios de vazão, calculou-se o CUC e o CUD para ambas as metodologias. A classificação do CUC foi excelente para todas as avaliações; com o CUD, 83,4 % das avaliações foram excelentes com a metodologia de amostragem com 16 pontos e 97,3 % com a metodologia de 32 pontos. Nenhum dos processos obteve capacidade de processo aceitável para processo em uso, quando determinados os limites de controle estatístico. Os processos de irrigação e fertirrigação mais passíveis de melhora e consequente aumento de capacidade de processo foram com as pressões de entrada de 150 e 200 kPa.

Nos últimos anos diversas áreas do setor produtivo vêm experimentando acelerados avanços tecnológicos e, desta forma, exigindo ferramentas cada vez mais específicas para monitorar e avaliar estes processos. Melhorias significativas nos processos de medições das características de qualidade têm sido observadas. Em relação ao controle de processo, em 1924, Walter Shewhart desenvolveu o conceito estatístico das cartas de controle para processos cujos dados sejam independentes e normalmente distribuídos, suposição esta que deve ser atendida para a construção das cartas de controle. Este artigo tem como objetivo mostrar a aplicação das cartas de controle estatístico de processo, no setor de pintura da Empresa Metasa, Rio Grande do Sul, Brasil, cuja característica do processo de pintura industrial analisada foi à espessura da camada de tinta. Os dados foram coletados levando em consideração, as seqüências que constituem o processo da aplicação da tinta (demãos de pintura), procurando-se oferecer uma melhoria sensível nos níveis de qualidade desse setor, com o objetivo de reduzir custos de produção. Os resultados encontrados são de grande importância para a empresa, pois foram estabelecidos os limites de controle que permitirão monitorar os processos. Para os casos onde a análise, entretanto, diagnosticou a permanência do processo fora de controle, se fez necessário o estudo das causas da variabilidade do mesmo. / In the last years many areas in the productive section have experienced fast technologic progress and, this way, demanding even more specific tools to control and assess these processes. Significant improvement in the processes of quality characteristics measurements has been noted. Regarding the process control, in 1924, Walter Shewhart (1931) developed the statistic concept of control letters to processes which data are independent and normally distributed, supposition that must be understood to control letters construction. This article has the goal to show the process statistic control letters, in the painting sector of the Company Metasa, Rio Grande do Sul, Brazil, which process characteristic of industrial painting analyzed was the paint coat thickness. The data were collected taking into consideration, the sequences that form the paint application process (painting coating), searching to offer a sensible improvement in the quality levels of this sector, with the objective of reducing production costs. The results found are of great importance to the company, since limits of control were established that will allow monitor the processes. For the cases where the analysis, otherwise, diagnosed the process permanence out of control, the study of their variability causes was necessary.

The master’s thesis is focused on the reduction of rejection rate in production of plastic bowls with the use of statistic methods. The theoretical part of this thesis describes among others Statistical Process Control, Process capability and types regulatory diagrams. The basis for the practical part is data collection over a certain period of production, from which the percentage of the rejection rate is evaluated. Experiments and corrective actions are designed to improve the process and thereby reduce scrap.

Master’s thesis describes statistical process control as a support for company management. Statistical process control methods and tools are introduced. Requirements for automotive industry are stated specifically for IATF 16949 standard and VDA 6.3 process audit method. Thesis presents current state in company Sanmina-SCI Czech Republic s.r.o regarding statistical regulation. Applies statistical process controls into the new process considering automotive requirements. It is all happening together with a new business introduction of automotive customer.

The thesis is focused on the analysis of the multiplex cinema market in the Czech Republic. The thesis evaluates the performance of selected multiplex with the help of statistical tools, time series, regression analysis and control charts. The current state is reviewed on the basis of results of the analysis and outlines the possible future development.

No description available.

The volume of data acquired in production systems continues to expand. Emerging imaging technologies, such as machine vision systems (MVSs) and 3D surface scanners, diversify the types of data being collected, further pushing data collection beyond discrete dimensional data. These large and diverse datasets increase the challenge of extracting useful information. Unfortunately, industry still relies heavily on traditional quality methods that are limited to fault detection, which fails to consider important diagnostic information needed for process recovery. Modern measurement technologies should spur the transformation of statistical process control (SPC) to provide practitioners with additional diagnostic information. This dissertation focuses on how MVSs and 3D laser scanners can be further utilized to meet that goal. More specifically, this work: 1) reviews image-based control charts while highlighting their advantages and disadvantages; 2) integrates spatiotemporal methods with digital image processing to detect process faults and estimate their location, size, and time of occurrence; and 3) shows how point cloud data (3D laser scans) can be used to detect and locate unknown faults in complex geometries. Overall, the research goal is to create new quality control tools that utilize high density data available in manufacturing environments to generate knowledge that supports decision-making beyond just indicating the existence of a process issue. This allows industrial practitioners to have a rapid process recovery once a process issue has been detected, and consequently reduce the associated downtime. / Ph. D.

In epidemiology it is often useful to monitor disease occurrences prospectively to determine the location and time when clusters of disease are forming. This aids in the prevention of illness and injury of the public and is the reason spatio-temporal disease surveillance methods are implemented. Care must be taken in the design and implementation of these types of surveillance methods so that the methods provide accurate information on the development of clusters. Here two spatio-temporal methods for prospective disease surveillance are considered. These include the local Knox monitoring method and a new wavelet-based prospective monitoring method. The local Knox surveillance method uses a cumulative sum (CUSUM) control chart for monitoring the local Knox statistic, which tests for space-time clustering each time there is an incoming observation. The detection of clusters of events occurring close together both temporally and spatially is important in finding outbreaks of disease within a specified geographic region. The local Knox surveillance method is based on the Knox statistic, which is often used in epidemiology to test for space-time clustering retrospectively. In this method, a local Knox statistic is developed for use with the CUSUM chart for prospective monitoring so that epidemics can be detected more quickly. The design of the CUSUM chart used in this method is considered by determining the in-control average run length (ARL) performance for different space and time closeness thresholds as well as for different control limit values. The effect of nonuniform population density and region shape on the in-control ARL is explained and some issues that should be considered when implementing this method are also discussed. In the wavelet-based prospective monitoring method, a surface of incidence counts is modeled over time in the geographical region of interest. This surface is modeled using Poisson regression where the regressors are wavelet functions from the Haar wavelet basis. The surface is estimated each time new incidence data is obtained using both past and current observations, weighing current observations more heavily. The flexibility of this method allows for the detection of changes in the incidence surface, increases in the overall mean incidence count, and clusters of disease occurrences within individual areas of the region, through the use of control charts. This method is also able to incorporate information on population size and other covariates as they change in the geographical region over time. The control charts developed for use in this method are evaluated based on their in-control and out-of-control ARL performance and recommendations on the most appropriate control chart to use for different monitoring scenarios is provided. / Ph. D.

A common problem encountered in practice is determining when it is appropriate to change the sampling interval for control charts. This thesis examines this problem for Shewhart X̅ charts. Duncan's economic model (1956) is used to develop a relationship between the most appropriate sampling interval and the present rate of"disturbances,” where a disturbance is a shift to an out of control state. A procedure is proposed which switches the interval to convenient values whenever a shift in the rate of disturbances is detected. An example using simulation demonstrates the procedure. / M.S.

The over-adjustment means that the process is adjusted unnecessarily when a false alarm occurs. It may result in shifts in process mean and variance affecting the quality of products and have the effect of an increase in variability and cost. In this paper, the economic variable sample interval (VSI) standard and control charts are proposed to monitor effectively the mean and variance of the over-adjusted process. We use a Markov chain approach to derive the design parameters of the standard and charts by the minimum of the cost function. An example of shampoo making process is used to illustrate the application and performance of the proposed VSI standard and charts in detecting shifts in process mean and variance. Furthermore, we compare the cost and performances for the economic FSI (fixed sampling interval) and VSI control charts. Support for this research was provided in part by the National Science Council of the Republic of China, grant No. NSC 94-2118-M-004-003. / The over-adjustment means that the process is adjusted unnecessarily when a false alarm occurs. It may result in shifts in process mean and variance affecting the quality of products and have the effect of an increase in variability and cost. In this paper, the economic variable sample interval (VSI) standard and control charts are proposed to monitor effectively the mean and variance of the over-adjusted process. We use a Markov chain approach to derive the design parameters of the standard and charts by the minimum of the cost function. An example of shampoo making process is used to illustrate the application and performance of the proposed VSI standard and charts in detecting shifts in process mean and variance. Furthermore, we compare the cost and performances for the economic FSI (fixed sampling interval) and VSI control charts. Support for this research was provided in part by the National Science Council of the Republic of China, grant No. NSC 94-2118-M-004-003.