RESEÑAS

(…)En noviembre de 2000 tuvo lugar en la UIMP de Valencia un Seminario que, bajo el título La actitud ilustrada, reunió a una serie de destacados investigadores universitarios para discutir en torno a tan crucial aspecto del siglo XVIII. Más recientemente, los coordinadores de aquel evento, Eduardo Bello y Antonio Rivera, han editado, a través de la Biblioteca Valenciana, los resultados de ese debate. En el volumen que ahora se presenta con el mismo nombre se recogen las aportaciones de los diez intervinientes, cuyas principa¬les líneas argumentativas resumiremos más adelante (…

Multiple Hashing Integration for Real-Time Large Scale Part-to-Part Video Matching

A real-time large scale part-to-part video matching algorithm, based on the cross correlation of the intensity of motion curves, is proposed with a view to originality recognition, video database cleansing, copyright enforcement, video tagging or video result re-ranking. Moreover, it is suggested how the most representative hashes and distance functions - strada, discrete cosine transformation, Marr-Hildreth and radial - should be integrated in order for the matching algorithm to be invariant against blur, compression and rotation distortions: (R; _) 2 [1; 20]_[1; 8], from 512_512 to 32_32pixels2 and from 10 to 180_. The DCT hash is invariant against blur and compression up to 64x64 pixels2. Nevertheless, although its performance against rotation is the best, with a success up to 70%, it should be combined with the Marr-Hildreth distance function. With the latter, the image selected by the DCT hash should be at a distance lower than 1.15 times the Marr-Hildreth minimum distance

Alteration mechanisms on the stones of the Cathedral of Granada (Spain)

Español: Se analizan los diversos mecanismos de alteración que actúan sobre los materiales pétreos usados en la Catedral de Granada. Se estudia con detalle la acción del agua, influencia antropogénica, oscilaciones térmicas, factores de incompatibilidad, movimientos sísmicos y factores de tipo biológico. Inglés: Alteration mechanisms on the stones of the Catedral of Granada, Spai

RESEÑAS

(…)En noviembre de 2000 tuvo lugar en la UIMP de Valencia un Seminario que, bajo el título La actitud ilustrada, reunió a una serie de destacados investigadores universitarios para discutir en torno a tan crucial aspecto del siglo XVIII. Más recientemente, los coordinadores de aquel evento, Eduardo Bello y Antonio Rivera, han editado, a través de la Biblioteca Valenciana, los resultados de ese debate. En el volumen que ahora se presenta con el mismo nombre se recogen las aportaciones de los diez intervinientes, cuyas principa¬les líneas argumentativas resumiremos más adelante (…

A simulation method to estimate closing forces in car-sealing rubber elements

The door-closing process can reinforce the impression of a solid, rock-proof, car body or of a rather cheap, flimsy vehicle. As there are no real prototypes during rubber profile bidding-out stages, engineers need to carry out non-linear numerical simulations that involve complex phenomena as well as static and dynamic loads for several profile candidates. This paper presents a structured virtual design tool based on FEM, including constitutive laws and incompressibility constraints allowing to predict more realistically the final closing forces and even to estimate sealing overpressure as an additional guarantee of noise insulation. Comparisons with results of physical tests are performed

Detection of human vital signs in hazardous environments by means of video magnification

In cases of natural disasters, epidemics or even in dangerous situations like an act of terrorism, battle fields, a shooting or a mountain accident, finding survivors is a challenge. In these kind of situations it is sometimes critical to know if a person has vital signs or not, without the need to be in contact with the victim, thus avoiding jeopardizing the lives of the rescue workers. In this work, we propose the use of video magnification techniques to detect small movements in human bodies due to breathing that are invisible to the naked eye. Two different video magnification techniques, intensity-based and phase-based, were tested. The utility of these techniques to detect people who are alive but injured in risk situations was verified by simulating a scene with three people involved in an accident. Several factors such as camera stability, distance to the object, light conditions, magnification factor or computing time were analyzed. The results obtained were quite positive for both techniques, intensity-based method proving more adequate if the interest is in almost instant results whereas the phase-based method is more appropriate if processing time is not so relevant but the degree of magnification without excessive image noise

Morfología macroscópica de alteración de la piedra del conjunto catedralicio de Granada/España

Los principales factores de alteración que actúan en el conjunto catedralicio de Granada son, uno natural de origen térmico, dadas las bajas temperaturas que se alcanzan en invierno, y las grandes oscilaciones térmicas que se registran durante gran parte del año, y los de origen antropogénico, fundamentalmente los de mal uso de elementos de sujeción metálicos oxidables y los de contaminación atmosférica debida a productos de combustión. De esta forma, los mecanismos de alteración primordiales son los de heladicidad por la expansión producida por la congelación del agua retenida en los poros y microgrietas, sobre todo en los elementos arquitectónicos de mayor superficie de exposición y en su orientación umbría. Los indicadores a que ello conduce son las fisuras y fragmentaciones. Así, muchos elementos de piedra de Santa Pudia de la crestería de la Capilla Real se han perdido y los que quedan se encuentran muy degradados. La piedra de Sierra Elvira de las cornisas, más compacta, también se ve afectada por este mecanismo, iniciado por las microgrietas provocadas por dilataciones diferenciales debidas a oscilaciones térmicas, que facilitaron el acceso al agua. La expansión de hierros al oxidarse ha provocado la fracturación y fisuración de gran número de elementos ornamentales como bolas, pináculos, etc, que han obligado al desmontaje de muchos de ellos por el riesgo de caída, sobre todo en las terrazas superiores del monumento. Los mecanismos de disolución, ciclos de cristalización y acción química han conducido a la pérdida abundante de materia, tanto en forma de arenizaciones, sobre todo en las zonas de mayor humedad, como de formación de huecos (picados, alveolizaciones, estriados), en aquellas zonas más expuesta al viento. Esto afecta de forma generalizada a las zonas bajas en todo el perímetro del edificio, excepto en gran parte de la fachada principal, así como en todos los antepechos y en las superficies situadas debajo de las cornisas. Estas arenizaciones se ven favorecidas cuando existen placas biológicas o depósitos de inquemados, siendo estos últimos de mayor abundancia en las superficies más cercanas a la Gran Vía y en su orientación hacia ésta. Por último, y sobre todo por su repercusión estética, es necesario mencionar los abundantes depósitos de guano de palomino, cuya mayor presencia se da en la fachada principal.The main factors of deterioration that affect the Cathedral Whole of Granada are one of natural thermic origin due to the low temperatures during the winters and the higher thermic oscillations and those of anthropogenical origin: fundamentally the oxidation of metallic elements and atmospheric pollution due to burnt products. For this reason, the more important deterioration mechanisms arethe freezing ones due to the expansión produced in the v^ater retained inside the pores and microcracks, fundamentally in the architectonic elements with high expositional surface and in their shady orientation; the main indicators produced are fissuring and spalling. In this way, a lot of elements of Santa Pudia stone located in the Royal Chapel crenellations have disappeared and the rest are very deteriorated. The more compact Sierra Elvira stone used on the upper zone of the cornices has also been affected by the freezing mechanism, which starts with the microcracks produced by differential dilatations due to the thermic oscillations which made the water access easy. The iron corrosión and later expansión of the oxidation products has provoked the cracking and fissuring of many ornamental elements like balls, pinnacles, etc, and this situation has obliged their dismantling on the upper zones due to the danger to the public. The mechanisms of dissotution, crystallization cycles and Chemical action have led to abundant material loosening in the form of grain disgregation overcoats on the higher humidity zones, and formation of hollows (pitting, alveolar erosión, striations) in the zones more exposed to the winds. This situation is generalized in the lower zones of the monument, except on the main fagade, and in the parapets and lower zones of the cornices. The grain disgregations are more important when biological crusts or unburned deposits exist, the latter being of major abundance on the surfaces near the Gran Vía and in its orientation. It is necessary to mention the pigeon dung deposits, very important in the main fagade, with greater stetical repercussion

Decay and treatment of Macael White Marble

This paper reports the process of deterioration of the white marble used in the Alhambra of Granada, and its consequences. Variations in mineralogical composition, micro- scopic topology, hardness, compressive strength, propagation of ultrasonic waves, absorption and diffusion of water and properties related to the pore structure were studied. The relationships between these factors, the visible deterioration and possible mechanisms are discussed. A preliminary evaluation of some protective treatments was car- ried out. The results can also be applied to white Macael marble used in other monuments in an environment with wide fluctuations in temperature and relative humidity