11 resultados para quality control

em Universidad Politécnica de Madrid


Relevância:

100.00% 100.00%

Publicador:

Resumo:

There are many industries that use highly technological solutions to improve quality in all of their products. The steel industry is one example. Several automatic surface-inspection systems are used in the steel industry to identify various types of defects and to help operators decide whether to accept, reroute, or downgrade the material, subject to the assessment process. This paper focuses on promoting a strategy that considers all defects in an integrated fashion. It does this by managing the uncertainty about the exact position of a defect due to different process conditions by means of Gaussian additive influence functions. The relevance of the approach is in making possible consistency and reliability between surface inspection systems. The results obtained are an increase in confidence in the automatic inspection system and an ability to introduce improved prediction and advanced routing models. The prediction is provided to technical operators to help them in their decision-making process. It shows the increase in improvement gained by reducing the 40 % of coils that are downgraded at the hot strip mill because of specific defects. In addition, this technology facilitates an increase of 50 % in the accuracy of the estimate of defect survival after the cleaning facility in comparison to the former approach. The proposed technology is implemented by means of software-based, multi-agent solutions. It makes possible the independent treatment of information, presentation, quality analysis, and other relevant functions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this paper, we use ARIMA modelling to estimate a set of characteristics of a short-term indicator (for example, the index of industrial production), as trends, seasonal variations, cyclical oscillations, unpredictability, deterministic effects (as a strike), etc. Thus for each sector and product (more than 1000), we construct a vector of values corresponding to the above-mentioned characteristics, that can be used for data editing.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

La emisión de polvo por efecto del viento desde depósitos de residuos mineros o industriales y el paso de vehículos en vías no pavimentadas, es un problema que afecta las actividades productivas; el ambiente y la salud de las personas que permanecen en el área contaminada. En Chile, en los últimos años la sensibilidad social y las exigencias ambientales han aumentado, así como la oferta de diferentes supresores y tecnologías de aplicación. Se han revisado las causas que provocan emisión de polvo y las tecnologías disponibles en Chile para la supresión de polvo, además de las metodologías y normativa para evaluar el desempeño de los materiales tratados con diferentes supresores. En algunos casos no es posible comparar propiedades de desempeño, como durabilidad, dosis a aplicar y frecuencia de las aplicaciones, entre otros aspectos. Los procedimientos descritos en la norma NCh3266-2012 permiten evaluar la erosión eólica en depósitos de residuos, sitios eriazos y caminos no pavimentados, entre otros, junto con evaluar el desempeño de diferentes tipos de supresores de polvo a partir de datos objetivos comparables. Esto permite seleccionar el supresor más adecuado, mejorar la eficiencia de los tratamientos, optimizar los costos y mejorar los procesos productivos. Palabras clave: Erosión-eólica, supresor de polvo, residuos-mineros, caminos-no pavimentados. Dust emissions by wind effect from mining deposits or industrial waste and passing vehicles on unpaved roads, is a problem that affects the productive activities; the environment and the health of those who remain in the contaminated area. The social sensitivity and environmental requirements on this issue in Chile have increased, as well as offering different suppressors and application technologies. Have been reviewed the causes of dust emission and technologies available in Chile for dust suppression, plus methodologies and standards for assessing the performance of the treated materials with different suppressors. In some cases it is not possible to compare performance properties such as durability, application dose and frequency of applications, among others aspects. The procedures described in the NCh 3266-2012 standard allows the assessment of wind erosion in waste deposits, vacant lots and unpaved roads, among others, along with evaluating the performance of different types of dust suppressants from comparable objective data. This allows selecting the most suitable suppressor, improve efficiency of treatments, optimize costs and improve production processes. Keywords: Wind-erosion, dust-suppressor, mining-waste, unpavedroads

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Quality is the threshold or minimum level required to satisfy the consumer´s demands. In construction the quality is objective, and established by standards. It is very difficult to establish the costs of “no quality” in construction. Each precast unit shall be traceable to a specific set of quality control records.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

There is remarkable growing concern about the quality control at the time, which has led to the search for methods capable of addressing effectively the reliability analysis as part of the Statistic. Managers, researchers and Engineers must understand that 'statistical thinking' is not just a set of statistical tools. They should start considering 'statistical thinking' from a 'system', which means, developing systems that meet specific statistical tools and other methodologies for an activity. The aim of this article is to encourage them (engineers, researchers and managers) to develop a new way of thinking.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Due to the fast rate of peach post-harvest ripening, damage due to mechanical handling, externally appreciated as bruises and soft areas, is a real problem that leads to an early harvesting and poor quality of the fruits, as perceived by the consumers. More and more, the European consumer asks for good taste and freshness of fruits and vegetables, and these quality factors are not included in standards, nor in most of the producers' practices. Fruit processing and marketing centres (co-operatives) are increasingly interested in adopting quality controls in their processes. ISO 9000 procedures are being applied in some food areas, primarily milk and meat processors, but no generalised procedures have been developed until the present time to be applied to fresh product processes. All different peach and nectarine varieties that are harvested and handled in Murcia cooperatives and sold in a large supermarket in Madrid were analysed during the whole 1997 season (early May to late August). A total number of 78 samples of 25 fruits (co-operative) or 10 fruits (market), were tested in the laboratory for mechanical, optical, chemical and tasting quality. The variability and relationships between all these quality parameters are presented and discussed, and sampling unit sizes which would be advisable for quality control are calculated.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

When the fresh fruit reaches the final markets from the suppliers, its quality is not always as good as it should, either because it has been mishandled during transportation or because it lacks an adequate quality control at the producer level, before being shipped. This is why it is necessary for the final markets to establish their own quality assessment system if they want to ensure to their customers the quality they want to sell. In this work, a system to control fruit quality at the last level of the distribution channel has been designed. The system combines rapid control techniques with laboratory equipment and statistical sampling protocols, to obtain a dynamic, objective process, which can substitute advantageously the quality control inspections carried out visually by human experts at the reception platform of most hypermarkets. Portable measuring equipment have been chosen (firmness tester, temperature and humidity sensors...) as well as easy-to-use laboratory equipment (texturometer, colorimeter, refractometer..,) combining them to control the most important fruit quality parameters (firmness, colour, sugars, acids). A complete computer network has been designed to control all the processes and store the collected data in real time, and to perform the computations. The sampling methods have been also defined to guarantee the confidence of the results. Some of the advantages of a quality assessment system as the proposed one are: the minimisation of human subjectivity, the ability to use modern measuring techniques, and the possibility of using it also as a supplier's quality control system. It can be also a way to clarify the quality limits of fruits among members of the commercial channel, as well as the first step in the standardisation of quality control procedures.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Este proyecto tiene por objeto desarrollar una sistemática de control metrológico para vigilar la exactitud de los medidores volumétricos de desplazamiento positivo que operan en las compañías logísticas de hidrocarburos para la transferencia de custodia que están en el cargadero y se ensayan in situ para obtener su meter factor. El punto de partida son las hojas primarias de las calibraciones generadas frente a sus patrones y el prover que nos facilitan las compañías. Dado el elevado número de ensayos y debido a que estos medidores no tienen gráficos de control estables, el enfoque del tratamiento ha sido un etiquetado para realizar un control de inestabilidad y calidad de los ensayos y así, determinar equipos anómalos. Para la búsqueda de equipos atípicos se ha desarrollado el filtro de Tukey para el estudio de la estadística descriptiva de los valores del meter factor. Entre los dos métodos se han obtenido una clasificación de equipos vigilables, recalibrables y sustituibles para facilitar a las compañías logísticas. ABSTRACT The aim of this project is to develop a systematic metrological control to monitor the accuracy of the positive displacement flow meters operating in oil logistics companies for custody transfer which are in the loading track facilities and it are tested in-situ to obtain the meter factor. Due to the high number of assays that meters don´t have stable graphics of control, the approach of data processing has been a labeled to perform an instability and quality control of assays for establish anomalous meters. To find outliers meters is developed the filter of Turkey to study the descriptive statistics of meter factor values. Between both analytical methods is obtained a classification of controllable, recalibrables and replaceable meters to provide to the logistic company.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Strict technical quality assurance procedures are essential for PV plant bankability. When large-scale PV plants are concerned, this is typically accomplished in three consecutive phases: an energy yield forecast, that is performed at the beginning of the project and is typically accomplished by means of a simulation exercise performed with dedicated software; a reception test campaign, that is performed at the end of the commissioning and consists of a set of tests for determining the efficiency and the reliability of the PV plant devices; and a performance analysis of the first years of operation, that consists in comparing the real energy production with the one calculated from the recorded operating conditions and taking into account the maintenance records. In the last six years, IES-UPM has offered both indoor and on-site quality control campaigns for more than 60 PV plants, with an accumulated power of more than 300 MW, in close contact with Engineering, Procurement and Construction Contractors and financial entities. This paper presents the lessons learned from such experience.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Background: In recent years, Spain has implemented a number of air quality control measures that are expected to lead to a future reduction in fine particle concentrations and an ensuing positive impact on public health. Objectives: We aimed to assess the impact on mortality attributable to a reduction in fine particle levels in Spain in 2014 in relation to the estimated level for 2007. Methods: To estimate exposure, we constructed fine particle distribution models for Spain for 2007 (reference scenario) and 2014 (projected scenario) with a spatial resolution of 16x16 km2. In a second step, we used the concentration-response functions proposed by cohort studies carried out in Europe (European Study of Cohorts for Air Pollution Effects and Rome longitudinal cohort) and North America (American Cancer Society cohort, Harvard Six Cities study and Canadian national cohort) to calculate the number of attributable annual deaths corresponding to all causes, all non-accidental causes, ischemic heart disease and lung cancer among persons aged over 25 years (2005-2007 mortality rate data). We examined the effect of the Spanish demographic shift in our analysis using 2007 and 2012 population figures. Results: Our model suggested that there would be a mean overall reduction in fine particle levels of 1mg/m3 by 2014. Taking into account 2007 population data, between 8 and 15 all-cause deaths per 100,000 population could be postponed annually by the expected reduction in fine particle levels. For specific subgroups, estimates varied from 10 to 30 deaths for all non-accidental causes, from 1 to 5 for lung cancer, and from 2 to 6 for ischemic heart disease. The expected burden of preventable mortality would be even higher in the future due to the Spanish population growth. Taking into account the population older than 30 years in 2012, the absolute mortality impact estimate would increase approximately by 18%. Conclusions: Effective implementation of air quality measures in Spain, in a scenario with a short-term projection, would amount to an appreciable decline infine particle concentrations, and this, in turn, would lead to notable health-related benefits. Recent European cohort studies strengthen the evidence of an association between long-term exposure to fine particles and health effects, and could enhance the health impact quantification in Europe. Air quality models can contribute to improved assessment of air pollution health impact estimates, particularly in study areas without air pollution monitoring data.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

El proyecto tiene por objeto la realización de los estudios técnicos, económicos y de mercado necesarios para definir la estrategia de creación de un Centro Tecnológico en Puertollano (Ciudad Real), ya que no existe en Castilla-La Mancha y tampoco en España un Laboratorio de estas características que trate conjuntamente campos muy demandados por los sectores de las Energías Renovables y la Industria Energética, lo que potenciará en un futuro inmediato un importante campo de negocio. Con el propósito de tener una estrategia adecuada en el desarrollo e implantación de este Centro se ha realizado un estudio de la optimización de los servicios a prestar mediante la implantación de Sistemas de Gestión de Calidad y Sistemas de Gestión de Actividades de Investigación, Desarrollo e Innovación (I+D+I) en relación con la actividad del negocio y fomentar en este aspecto la colaboración de las Administraciones y Universidades. El déficit en la competitividad de la economía española afecta a los conceptos íntimamente ligados de calidad y seguridad. Las exigencias cada vez mayores de seguridad y controles metrológicos de normativas europeas en el uso de energías, combustibles e industria, prevén un horizonte muy interesante para los servicios colaterales del Control de Calidad. ABSTRACT The main objetive of this project is to make a technical, economical and marketing study to define the creation strategy of a Technological Centre in Puertollano (Ciudad Real), since there is none in Castilla-La Mancha, or in Spain. Such laboratory would jointly manage fields of high demand by the Renevable Energy Industry sectors, that would enable the development of an important business field. With the purpose of having an appropriate strategy for the development and implementation of this centre, a service optimization study has been made, using the Quality Management Investigation, and ID Systems. This is related to business activities and seeks to foment the colaboration with the Administration and universities. The competitiviness déficit of the Spanish Economy, affects some closely related concepts of quality and security. The constantly growing requirements of security and metrological controls, due to energy, fuel and industry european laws, anticípate an interesting progress for the colateral services of Quality Control.