1,971 research outputs found

    Modelo Predictivo Borroso de la Aceleración de Cabeceo de Buque de Alta Velocidad

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    An adaptable fuzzy inference technique is being described in order to generate predictive models of the acceleration of the pitching of a high speed vessel, from the data obtained from the web on an experiment conducted by the University of Iowa. The geometry of interest in the experiment is a scale model of the type 1/46.6 of the DTMB model 5415 (DDG-51). The fuzzy algorithm for the generation of the predictive model uses a triangular partition with a 0.5 overlapping and consequents of the Singleton type. The consequents are adjusted in an automatic fashion by using recursive least squares. The algorithm shows a very low computational complexity rate which allows for it to be used for on line identification.Se describe una técnica de inferencia borrosa adaptativa para generar modelos predictivos de la aceleración de cabeceo de un buque de alta velocidad, a partir de datos obtenidos de la web de un experimento realizado en la Universidad de Iowa. En el experimento, la geometría de interés es un modelo a escala 1/46.6 del DTMB modelo 5415 (DDG-51). El algoritmo borroso para la generación del modelo predictivo emplea partición triangular con solapamiento de 0.5 y consecuentes tipo singlenton. Los consecuentes son ajustados de manera automática empleando mínimos cuadrados recursivos. El algoritmo presenta una baja complejidad computacional lo que permite su empleo para identificación en línea

    New design parameters for biparabolic beach profiles (SW Cadiz, Spain)

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    165 profiles of seventy-one beaches along the Gulf of Cadiz (SW, Spain) were studied to improve the formulation of the beach profile in tidal seas. Maritime climate, degree of energy exposure and size of the sand grains were taken into account to study the two sections of the biparabolic profile. The objective of the study was the determination of more accurate formulations of the design parameters for the equilibrium profile that involves tidal seas. These formulations were modelled and validated based on existing profiles to quantify the error existing between the real profile and the modelling. This comparative analysis was extended by considering the formulations proposed by other authors. The best results were obtained with the proposal presented herein

    A Design Parameter for Reef Beach Profiles—A Methodology Applied to Cadiz, Spain

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    The southwestern coast of Spain is in a tidal zone (mesotidal) which causes the equilibrium profile to be developed in two different sections: the breakage section and the swash section. These two sections give rise to the typical bi-parabolic profile existing in tidal seas. The existence of areas with reefs/rocks which interrupt the normal development of the typical bi-parabolic profile causes different types of beach profiles. The objective of this article is designing an easy methodology for determining new formulations for the design parameters of the equilibrium profile of beaches with reefs in tidal seas. These formulations are applied on 16 profiles to quantify the error between the real profile data and the modelling results. A comparative analysis is extended to the formulations proposed by other authors, from which it is found that better results are obtained with the new formulations

    Revisión de los sistemas de microondas para aplicaciones militares

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    Este TFG tiene por objeto realizar una revisión de las tecnologías utilizadas en el sector militar, relacionadas con los sistemas de microondas y cómo estas tecnologías se utilizan en la actualidad en el sector civil. Como punto de partida realizará un análisis histórico ambientado en la II Guerra Mundial, y las tecnologías utilizadas en el entorno de la transmisión de ondas de microondas, se analizará en profundidad el sistema de rádar.Escuela Técnica Superior de Ingeniería de TelecomunicaciónUniversidad Politécnica de Cartagen

    Virtual resources for the improvement of teaching in the course of Port and Coastal Engineering (dregree in Civil Engineering)

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    Port and Coastal Engineering is a subject included in the third year of the degree in Civil Engineering (Civil Constructions and Hydrology specialty) taught at the Polytechnic School of Algeciras. As this is a subject with a very specific syllabus, there is no textbook (or even appropriate references) that contemplates all the related topics of the whole course. Moreover, there are many students who, for different reasons (repeaters, Erasmus, labour obligations, ...), cannot attend the regular classes. This lack of attendance has been leading to another problem: this kind of students have been leaving the subject for several years. In addition, understanding of the basic concepts becomes even more complicated for Erasmus students enrolled in the subject because of the language barrier. In order to solve this problem, a project of teaching innovation has been launched which consists of the creation of a set of evaluable tasks for the different topics addressed to be performed by the students. In this way, the students are motivated to keep up-to-date the course contents. A comparison of the last year results with those of the preceding five years is provided. Finally, an analysis of the significance of the improvement is also presented

    Increase in the Erosion Rate Due to the Impact of Climate Change on Sea Level Rise: Victoria Beach, a Case Study

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    This article provides a general methodology for calculating the retreat of the coastline and the volume of sand necessary to renourish a beach due to sea level rise (SLR) in the medium-long term. An example is presented, Victoria Beach, and a projection is made for the years 2030, 2040, 2050, and 2100. The results obtained take into account global sea level rise (GSLR), which is worldwide, and local sea level rise (LSLR), which considers climate variability and vertical land movements. Regarding GSLR, data were provided by the projections from IPCC (Intergovernmental Panel on Climate Change) scenarios and empirical models, such as Rahmstorf and Pfeffer. The LSLR data came from the tide gauge station located in Cadiz. Finally, the results obtained showed that global warming impacts erosive effects and the subsequent volume of sand required to renourish beaches. The total sea level rise (TSLR) projections indicated for Victoria Beach are relatively higher than the GSLR projections. Even in the best IPCC scenario (RCP 2.6), Victoria Beach presents a significant erosion of 52 m, requiring a volume of sand of 1.0 Mm3 to supply renourishment.14 página

    Comparison of Three Operative Models for Estimating the Surface Water Deficit Using ASTER Reflective and Thermal Data

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    24 pages, 4 figures, 4 tables.-- Special Issue "Remote Sensing of Natural Resources and the Environment".Three operative models with minimum input data requirements for estimating the partition of available surface energy into sensible and latent heat flux using ASTER data have been evaluated in a semiarid area in SE Spain. The non-evaporative fraction (NEF) is proposed as an indicator of the surface water deficit. The best results were achieved with NEF estimated using the "Simplified relationship" for unstable conditions (NEF_Seguin) and with the S-SEBI (Simplified Surface Energy Balance Index) model corrected for atmospheric conditions (NEF_S-SEBIt,) which both produced equivalent results. However, results with a third model, NEF_Carlson, that estimates the exchange coefficient for sensible heat transfer from NDVI, were unrealistic for sites with scarce vegetation cover. These results are very promising for an operative monitoring of the surface water deficit, as validation with field data shows reasonable errors, within those reported in the literature (RMSE were 0.18 and 0.11 for the NEF, and 29.12 Wm-2 and 25.97 Wm-2 for sensible heat flux, with the Seguin and S-SEBIt models, respectively).This study received financial support from several different research projects: the integrated EU project, DeSurvey (A Surveillance System for Assessing and Monitoring of Desertification) (ref.: FP6- 00.950, Contract nº. 003950), the PROBASE (ref.: CGL2006-11619/HID) and CANOA (ref.: CGL2004-04919-C02-01/HID) projects funded by the Spanish Ministry of Education and Science; and the BACAEMA ('Balance de carbono y de agua en ecosistemas de matorral mediterráneo en Andalucía: Efecto del cambio climático', RNM-332) and CAMBIO ('Efectos del cambio global sobre la biodiversidad y el funcionamiento ecosistémico mediante la identificación de áreas sensibles y de referencia en el SE ibérico', RNM 1280) projects funded by the Junta de Andalucía (Andalusian Regional Government).Peer reviewe
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