6 resultados para Folcculation of mud bank seidments

em Universidad Politécnica de Madrid


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The geochemical fingerprint of sediment retrieved from the banks of the River Manzanares as it passes through the City of Madrid is presented here. The river collects the effluent water from several Waste Water Treatment (WWT) plants in and around the city, such that, at low flows, up to 60% of the flow has been treated. A total of 18 bank-sediment cores were collected along the course of the river, down to its confluence with the Jarama river, to the south–east of Madrid. Trace and major elements in each sample were extracted following a double protocol: (a) “Total” digestion with HNO3, HClO4 and HF; (b) “Weak” digestion with sodium acetate buffered to pH=5 with acetic acid, under constant stirring. The digests thus obtained were subsequently analysed by ICP-AES, except for Hg which was extracted with aqua regia and sodium chloride-hydroxylamine sulfate, and analysed by Cold Vapour-AAS. X-ray diffraction was additionally employed to determine the mineralogical composition of the samples. Uni- and multivariate analyses of the chemical data reveal the influence of Madrid on the geochemistry of Manzanares' sediments, clearly manifested by a marked increase in the concentration of typically “urban” elements Ag, Cr, Cu, Pb and Zn, downstream of the intersection of the river with the city's perimeter. The highest concentrations of these elements appear to be associated with illegal or accidental dumping of waste materials, and with the uncontrolled incorporation of untreated urban runoff to the river. The natural matrix of the sediment is characterised by fairly constant concentrations of Ce, La and Y, whereas changes in the lithology intersected by the river cause corresponding variations in Ca–Mg and Al–Na contents. In the final stretch of the river, the presence of carbonate materials seems to exert a strong geochemical control on the amount of Zn and, to a lesser extent, Cu immobilised in the sediments. This fact suggests that a variable but significant proportion of both elements may be susceptible to reincorporation in the aqueous phase under realistic environmental conditions.

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In this correspondence, the conditions to use any kind of discrete cosine transform (DCT) for multicarrier data transmission are derived. The symmetric convolution-multiplication property of each DCT implies that when symmetric convolution is performed in the time domain, an element-by-element multiplication is performed in the corresponding discrete trigonometric domain. Therefore, appending symmetric redun-dancy (as prefix and suffix) into each data symbol to be transmitted, and also enforcing symmetry for the equivalent channel impulse response, the linear convolution performed in the transmission channel becomes a symmetric convolution in those samples of interest. Furthermore, the channel equalization can be carried out by means of a bank of scalars in the corresponding discrete cosine transform domain. The expressions for obtaining the value of each scalar corresponding to these one-tap per subcarrier equalizers are presented. This study is completed with several computer simulations in mobile broadband wireless communication scenarios, considering the presence of carrier frequency offset (CFO). The obtained results indicate that the proposed systems outperform the standardized ones based on the DFT.

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This paper presents a model for determining value at operational risk ?OpVaR? in electric utilities, with the aim to confirm the versatility of the Bank for International Settlements (BIS) proposals. The model intends to open a new methodological approach in risk management, paying special attention to underlying operational sources of risk.

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Infrastructure concession is an alternative widely used by governments to increase investment. In the case of the road sector, the main characteristics of the concessions are: long-term projects, high investments in the early years of the contract and high risks. A viability analysis must be carried out for each concession and consider the characteristics of the project. When the infrastructure is located in a developing country, political and market growth uncertainties should be add in the concession project analysis, as well as economic instability, because they present greater risks. This paper is an analysis of state bank participation in road infrastructure finance in developing countries. For this purpose, we studied road infrastructure financing and its associated risks, and also the features of developing countries. Furthermore, we considered the issue of state banks and multilateral development banks that perform an important role by offering better credit lines than the private banks, in terms of cost, interest and grace period. Based on this study, we analyzed the Brazilian Development Bank - BNDES – and their credit supply to road infrastructure concessions. The results show that BNDES is the main financing agent for long-term investment in the sector, offering loans with low interest rates in Brazilian currency. From this research we argue that a single state bank should not alone support the increasing demand for finance in Brazil. Therefore, we conclude that there is a need to expand the supply of credit in Brazil, by strengthening private banks in the long-term lending market.

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Los sistemas de pago con móvil son una alternativa de pago a los medios de pago electrónicos tradicionales que están siendo cada vez más utilizados en nuestra sociedad. Son varios los factores que han llevado a la utilización de esta forma alternativa de pago. Los terminales móviles se han convertido en una herramienta casi vital para la sociedad, lo cual ha contribuido a una gran aceptación y desarrollo de los terminales móviles que cada vez cuentan con más funcionalidades. Gracias a esto, las comunicaciones móviles también están en constante evolución y ello ha influido notablemente para que se puedan desarrollar nuevos servicios e implementar nuevas funcionalidades en los terminales móviles. Por otro lado, la tendencia de los usuarios a usar cada día más los sistemas de pago electrónicos, intentando en la medida de lo posible prescindir del dinero en efectivo, también es un factor que ha permitido impulsar el desarrollo de este tipo de sistema de pagos emergentes. En el otro lado se encuentra el mundo empresarial, donde por un lado están las empresas de telecomunicaciones que no quieren dejar escapar esta oportunidad de negocio y están invirtiendo dinero para desarrollar nuevas infraestructuras que permitan el pago con móvil, y por otro lado se encuentran las entidades financieras que son necesarias para poder llevar a cabo los pagos a través del móvil, y por tanto tienen que formar parte de la solución llegando a los acuerdos necesarios con los proveedores de servicios. En este trabajo se realiza un análisis de las diferentes plataformas de pago por móvil existentes en la actualidad, prestando especial atención a los aspectos que tienen que ver con la seguridad y la disponibilidad y acceso de la información bancaria del usuario. Asimismo también se analiza la arquitectura de cada plataforma como su funcionamiento, aclarando la interacción y el papel que juegan las diferentes partes implicadas. Para ello hay un capítulo dedicado a la seguridad donde se presentan conceptos y protocolos que son aplicados en las soluciones de pagos electrónicos, y una descripción de los sistemas de pago electrónicos más usados actualmente, los cuales presentan muchas similitudes con los sistemas de pago con móvil. Por último se recogen diferentes experiencias llevadas a cabo en nuestro país de pagos con móvil, destacando la experiencia de los usuarios así como el método empleado. ABSTRACT. Mobile payment systems are payment methods alternative to traditional electronic payment ones that are being increasingly used in our society. Several factors have led to the use of this alternative form of payment. Mobile terminals have become almost a vital tool for society, which has contributed to a wide acceptance and development of mobile terminals that are getting more features all the time. As a result, mobile communications are also evolving and they have had such a great influence that they have developed new services and implemented new features in mobile terminals. What is more, the growing tendency among users to use electronic payment systems, trying to make their payments whithout cash as often as possible, is also a factor that has allowed the boost the development of such emerging payment systems. The other partner of these systems is the business world, where on one hand, the telecommunication companies that do not want to miss this business opportunity are investing funds to develop new infrastructures which enable the mobile payment, and on the other hand, the financial institutions that are necessary to carry out payments via mobile, and therefore need to be part of the solution reaching the necessary agreements with service providers, want their own saying and their own share of the potential profits. This report is an analysis of the different mobile payment platforms existing today, with particular attention to the aspects that have to do with security and the availability and acces of user’s bank information. Likewise, it also analyzes the architecture of each platform and its operation and interaction procedures, clarifying the role of the different parties involved. Previously there is a chapter that presents security concepts and protocols that are applied in electronic payment solutions, and a description of the electronic trade systems most widely used currently, which have many similarities with mobile payment systems. Finally, it shows different experiments carried out in our country of mobile payments, highlighting the experience of users as well as the method used.

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La presente investigación tiene como objetivo principal diseñar un Modelo de Gestión de Riesgos Operacionales (MGRO) según las Directrices de los Acuerdos II y III del Comité de Supervisión Bancaria de Basilea del Banco de Pagos Internacionales (CSBB-BPI). Se considera importante realizar un estudio sobre este tema dado que son los riesgos operacionales (OpR) los responsables en gran medida de las últimas crisis financieras mundiales y por la dificultad para detectarlos en las organizaciones. Se ha planteado un modelo de gestión subdividido en dos vías de influencias. La primera acoge el paradigma holístico en el que se considera que hay múltiples maneras de percibir un proceso cíclico, así como las herramientas para observar, conocer y entender el objeto o sujeto percibido. La segunda vía la representa el paradigma totalizante, en el que se obtienen datos tanto cualitativos como cuantitativos, los cuales son complementarios entre si. Por otra parte, este trabajo plantea el diseño de un programa informático de OpR Cualitativo, que ha sido diseñado para determinar la raíz de los riesgos en las organizaciones y su Valor en Riesgo Operacional (OpVaR) basado en el método del indicador básico. Aplicando el ciclo holístico al caso de estudio, se obtuvo el siguiente diseño de investigación: no experimental, univariable, transversal descriptiva, contemporánea, retrospectiva, de fuente mixta, cualitativa (fenomenológica y etnográfica) y cuantitativa (descriptiva y analítica). La toma de decisiones y recolección de información se realizó en dos fases en la unidad de estudio. En la primera se tomó en cuenta la totalidad de la empresa Corpoelec-EDELCA, en la que se presentó un universo estadístico de 4271 personas, una población de 2390 personas y una unidad de muestreo de 87 personas. Se repitió el proceso en una segunda fase, para la Central Hidroeléctrica Simón Bolívar, y se determinó un segundo universo estadístico de 300 trabajadores, una población de 191 personas y una muestra de 58 profesionales. Como fuentes de recolección de información se utilizaron fuentes primarias y secundarias. Para recabar la información primaria se realizaron observaciones directas, dos encuestas para detectar las áreas y procesos con mayor nivel de riesgos y se diseñó un cuestionario combinado con otra encuesta (ad hoc) para establecer las estimaciones de frecuencia y severidad de pérdidas operacionales. La información de fuentes secundarias se extrajo de las bases de datos de Corpoelec-EDELCA, de la IEA, del Banco Mundial, del CSBB-BPI, de la UPM y de la UC at Berkeley, entre otras. Se establecieron las distribuciones de frecuencia y de severidad de pérdidas operacionales como las variables independientes y el OpVaR como la variable dependiente. No se realizó ningún tipo de seguimiento o control a las variables bajo análisis, ya que se consideraron estas para un instante especifico y solo se determinan con la finalidad de establecer la existencia y valoración puntual de los OpR en la unidad de estudio. El análisis cualitativo planteado en el MGRO, permitió detectar que en la unidad de investigación, el 67% de los OpR detectados provienen de dos fuentes principales: procesos (32%) y eventos externos (35%). Adicionalmente, la validación del MGRO en Corpoelec-EDELCA, permitió detectar que el 63% de los OpR en la organización provienen de tres categorías principales, siendo los fraudes externos los presentes con mayor regularidad y severidad de pérdidas en la organización. La exposición al riesgo se determinó fundamentándose en la adaptación del concepto de OpVaR que generalmente se utiliza para series temporales y que en el caso de estudio presenta la primicia de aplicarlo a datos cualitativos transformados con la escala Likert. La posibilidad de utilizar distribuciones de probabilidad típicas para datos cuantitativos en distribuciones de frecuencia y severidad de pérdidas con datos de origen cualitativo fueron analizadas. Para el 64% de los OpR estudiados se obtuvo que la frecuencia tiene un comportamiento semejante al de la distribución de probabilidad de Poisson y en un 55% de los casos para la severidad de pérdidas se obtuvo a las log-normal como las distribuciones de probabilidad más comunes, con lo que se concluyó que los enfoques sugeridos por el BCBS-BIS para series de tiempo son aplicables a los datos cualitativos. Obtenidas las distribuciones de frecuencia y severidad de pérdidas, se convolucionaron estas implementando el método de Montecarlo, con lo que se obtuvieron los enfoques de distribuciones de pérdidas (LDA) para cada uno de los OpR. El OpVaR se dedujo como lo sugiere el CSBB-BPI del percentil 99,9 o 99% de cada una de las LDA, obteniéndose que los OpR presentan un comportamiento similar al sistema financiero, resultando como los de mayor peligrosidad los que se ubican con baja frecuencia y alto impacto, por su dificultad para ser detectados y monitoreados. Finalmente, se considera que el MGRO permitirá a los agentes del mercado y sus grupos de interés conocer con efectividad, fiabilidad y eficiencia el status de sus entidades, lo que reducirá la incertidumbre de sus inversiones y les permitirá establecer una nueva cultura de gestión en sus organizaciones. ABSTRACT This research has as main objective the design of a Model for Operational Risk Management (MORM) according to the guidelines of Accords II and III of the Basel Committee on Banking Supervision of the Bank for International Settlements (BCBS- BIS). It is considered important to conduct a study on this issue since operational risks (OpR) are largely responsible for the recent world financial crisis and due to the difficulty in detecting them in organizations. A management model has been designed which is divided into two way of influences. The first supports the holistic paradigm in which it is considered that there are multiple ways of perceiving a cyclical process and contains the tools to observe, know and understand the subject or object perceived. The second way is the totalizing paradigm, in which both qualitative and quantitative data are obtained, which are complementary to each other. Moreover, this paper presents the design of qualitative OpR software which is designed to determine the root of risks in organizations and their Operational Value at Risk (OpVaR) based on the basic indicator approach. Applying the holistic cycle to the case study, the following research design was obtained: non- experimental, univariate, descriptive cross-sectional, contemporary, retrospective, mixed-source, qualitative (phenomenological and ethnographic) and quantitative (descriptive and analytical). Decision making and data collection was conducted in two phases in the study unit. The first took into account the totality of the Corpoelec-EDELCA company, which presented a statistical universe of 4271 individuals, a population of 2390 individuals and a sampling unit of 87 individuals. The process was repeated in a second phase to the Simon Bolivar Hydroelectric Power Plant, and a second statistical universe of 300 workers, a population of 191 people and a sample of 58 professionals was determined. As sources of information gathering primary and secondary sources were used. To obtain the primary information direct observations were conducted and two surveys to identify the areas and processes with higher risks were designed. A questionnaire was combined with an ad hoc survey to establish estimates of frequency and severity of operational losses was also considered. The secondary information was extracted from the databases of Corpoelec-EDELCA, IEA, the World Bank, the BCBS-BIS, UPM and UC at Berkeley, among others. The operational loss frequency distributions and the operational loss severity distributions were established as the independent variables and OpVaR as the dependent variable. No monitoring or control of the variables under analysis was performed, as these were considered for a specific time and are determined only for the purpose of establishing the existence and timely assessment of the OpR in the study unit. Qualitative analysis raised in the MORM made it possible to detect that in the research unit, 67% of detected OpR come from two main sources: external processes (32%) and external events (35%). Additionally, validation of the MORM in Corpoelec-EDELCA, enabled to estimate that 63% of OpR in the organization come from three main categories, with external fraud being present more regularly and greater severity of losses in the organization. Risk exposure is determined basing on adapting the concept of OpVaR generally used for time series and in the case study it presents the advantage of applying it to qualitative data transformed with the Likert scale. The possibility of using typical probability distributions for quantitative data in loss frequency and loss severity distributions with data of qualitative origin were analyzed. For the 64% of OpR studied it was found that the frequency has a similar behavior to that of the Poisson probability distribution and 55% of the cases for loss severity it was found that the log-normal were the most common probability distributions. It was concluded that the approach suggested by the BCBS-BIS for time series can be applied to qualitative data. Once obtained the distributions of loss frequency and severity have been obtained they were subjected to convolution implementing the Monte Carlo method. Thus the loss distribution approaches (LDA) were obtained for each of the OpR. The OpVaR was derived as suggested by the BCBS-BIS 99.9 percentile or 99% of each of the LDA. It was determined that the OpR exhibits a similar behavior to the financial system, being the most dangerous those with low frequency and high impact for their difficulty in being detected and monitored. Finally, it is considered that the MORM will allows market players and their stakeholders to know with effectiveness, efficiency and reliability the status of their entities, which will reduce the uncertainty of their investments and enable them to establish a new management culture in their organizations.