Aplicación de la técnica SVM en el análisis forense de imágenes de dispositivos móviles

Uno de los problemas a tratar dentro del análisis forense digital es la identificación de la cámara que se ha usado para obtener una determinada imagen. Debido al aumento en el uso de teléfonos móviles con cámara integrada durante los últimos años, el trabajo está orientado a este tipo de dispositivos, proporcionando al investigador forense una herramienta específica para el análisis de este tipo de imágenes. En este trabajo se analiza la información EXIF contenida en un archivo de imagen y se comprueba porque no es una fuente fiable a la hora de obtener la marca y modelo de la cámara. Por eso desarrollamos un algoritmo que utiliza la información de los píxeles de la imagen. Está basado en las diferencias existentes en los métodos de procesamiento de la imagen que utilizan los distintos fabricantes, como el algoritmo de interpolación del color que tiene lugar en la matriz CFA del sensor, la corrección gamma o la corrección de puntos blancos. Estas diferencias originan un conjunto de huellas en la imagen que nos permitirían diferenciar la marca y modelo de la camara fuente. Para obtener estas huellas, extraemos un conjunto de características de las imagenes, entre las que se encuentran características de color, métricas de la calidad de la imagen y estadísticas wavelet. Para realizar la predicción de la marca y modelo de la camara utilizamos un clasificador SVM. Siguiendo un procedimiento análogo, se desarrolla otro algoritmo que permite saber si una imagen procede de una cámara o de un escáner. Finalmente, llevamos a cabo un conjunto de experimentos que demuestran la efectividad del algoritmo implementado. [ABSTRACT] One of the issues involved in digital forensics is the identification of the camera used to obtain a particular image. Due to the increase use of mobile phones with integrated camera in recent years, this work is aimed at this type of devices, providing to forensic investigator a specific tool for the analysis of images taken with mobile phones. In this work we analyze the EXIF information contained in an image file and we explain because it is not a reliable source if we want to extract the make and model of the camera from it. So we develop an algorithm that uses information from the pixels of the image. It is based on dferences in the image processing methods used by diferent manufacturers, such as color interpolation algorithm which takes place in the color filter array, gamma correction or white point correction. These diferences originate a set of footprints in the image that allow us to diferentiate the brand and model of the source camera. To obtain these footprints, we extract a feature set from the images, among which are color characteristics, image quality metrics and wavelet statistics. To predict the make and the model of camera we use an SVM classifier. Following a similar procedure, we develop another algorithm that let us know if an image comes from a camera or a scanner. Finally, we perform a series of experiments to prove the efectiveness of the implemented algorithm

Structure function and Multifractal spectrum applied to Digital Elevation Model

A Digital Elevation Model (DEM) provides the information basis used for many geographic applications such as topographic and geomorphologic studies, landscape through GIS (Geographic Information Systems) among others. The DEM capacity to represent Earth?s surface depends on the surface roughness and the resolution used. Each DEM pixel depends on the scale used characterized by two variables: resolution and extension of the area studied. DEMs can vary in resolution and accuracy by the production method, although there are statistical characteristics that keep constant or very similar in a wide range of scales. Based on this property, several techniques have been applied to characterize DEM through multiscale analysis directly related to fractal geometry: multifractal spectrum and the structure function. The comparison of the results by both methods is discussed. The study area is represented by a 1024 x 1024 data matrix obtained from a DEM with a resolution of 10 x 10 m each point, which correspond with a region known as ?Monte de El Pardo? a property of Spanish National Heritage (Patrimonio Nacional Español) of 15820 Ha located to a short distance from the center of Madrid. Manzanares River goes through this area from North to South. In the southern area a reservoir is found with a capacity of 43 hm3, with an altitude of 603.3 m till 632 m when it is at the highest capacity. In the middle of the reservoir the minimum altitude of this area is achieved

Allocation of 14C assimilated in late spring to tissue and biochemical stem components of cork oak (Quercus suber L.) over the seasons

Carbon distribution in the stem of 2-year-old cork oak plants was studied by 14CO2 pulse labeling in late spring in order to trace the allocation of photoassimilates to tissue and biochemical stem components of cork oak. The fate of 14C photoassimilated carbon was followed during two periods: the first 72 h (short-term study) and the first 52 weeks (long-term study) after the 14CO2 photosynthetic assimilation. The results showed that 14C allocation to stem tissues was dependent on the time passed since photoassimilation and on the season of the year. In the first 3 h all 14C was found in the polar extractives. After 3 h, it started to be allocated to other stem fractions. In 1 day, 14C was allocated mostly to vascular cambium and, to a lesser extent, to primary phloem; no presence of 14C was recorded for the periderm. However, translocation of 14C to phellem was observed from 1 week after 14CO2 pulse labeling. The phellogen was not completely active in its entire circumference at labeling, unlike the vascular cambium; this was the tissue that accumulated most photoassimilated 14C at the earliest sampling. The fraction of leaf-assimilated 14C that was used by the stem peaked at 57% 1 week after 14CO2 plant exposure. The time lag between C photoassimilation and suberin accumulation was ∼8 h, but the most active period for suberin accumulation was between 3 and 7 days. Suberin, which represented only 1.77% of the stem weight, acted as a highly effective sink for the carbon photoassimilated in late spring since suberin specific radioactivity was much higher than for any other stem component as early as only 1 week after 14C plant labeling. This trend was maintained throughout the whole experiment. The examination of microautoradiographs taken over 1 year provided a new method for quantifying xylem growth. Using this approach it was found that there was more secondary xylem growth in late spring than in other times of the year, because the calculated average cell division time was much shorter

GIS-Based Assessment of Banana Residual Biomass Potential for Ethanol Production and Power Generation: A Case Study

Banana is one of the most important fruit crops in the world. The plant bears one bunch in its life, leaving behind a large amount of agricultural residues (starchy and lignocellulosic biomass), which could be used for different purposes such as bioenergy. Ecuador is the largest exporter of banana fruits. In this work, the potential of banana residual biomass produced in the province of El Oro, Ecuador for bioenergy applications was assessed using Geographic Information Systems?GIS. The methodology included the assessment of biomass distribution, facility location, transport optimization and a novel virtual land parcel that allows for these kinds of studies in areas with lack of geo-referenced information. According to our approach, El Oro province has an available biomass potential of 190,102 t fm year?1 of starchy residual biomass and 198,602 t dm year?1 of lignocellulosic residual biomass. Two candidate points located at 79°51?12?W3°11?21?S and 79°52?49?W3°17?49?S were identified for the installment of energy conversion facilities supplied with residual biomass. From the available potential of starchy biomass it would be possible to obtain up to 19 million liters of bioethanol per year assuming an average yield of 101.2 l t?1 fresh matter; while the available lignocellulosic biomass, which energy content (Lower Heating Value, moisture free biomass) was determined at 12.9 MJ kg?1 on average, could be used for power generation with an installed capacity of 18 MW. Chemical characterization of the lignocellulosic biomass suggested that further studies should be undertaken regarding the potential application of these crop residues to second generation bioethanol

Continuous multi-criteria methods for crop and soil conservation planning on La Colacha (Río Cuarto, Province of Cordoba, Argentina)

Agro-areas of Arroyos Menores (La Colacha) west and south of Rand south of R?o Cuarto (Prov. of Cordoba, Argentina) basins are very fertile but have high soil loses. Extreme rain events, inundations and other severe erosions forming gullies demand urgently actions in this area to avoid soil degradation and erosion supporting good levels of agro production. The authors first improved hydrologic data on La Colacha, evaluated the systems of soil uses and actions that could be recommended considering the relevant aspects of the study area and applied decision support systems (DSS) with mathematic tools for planning of defences and uses of soils in these areas. These were conducted here using multi-criteria models, in multi-criteria decision making (MCDM); first of discrete MCDM to chose among global types of use of soils, and then of continuous MCDM to evaluate and optimize combined actions, including repartition of soil use and the necessary levels of works for soil conservation and for hydraulic management to conserve against erosion these basins. Relatively global solutions for La Colacha area have been defined and were optimised by Linear Programming in Goal Programming forms that are presented as Weighted or Lexicographic Goal Programming and as Compromise Programming. The decision methods used are described, indicating algorithms used, and examples for some representative scenarios on La Colacha area are given

Valor predictivo de la candidiasis oral como marcador de evolución a SIDA

Objetivo: Determinar la validez de la candidiasis oral (CO) como marcador clinico de evolucion en los pacientes infectados por el Virus de la Inmunodeficiencia Humana. Diseno del estudio: En 1992, se efectuo una exploracion oral a un colectivo de 200 pacientes infectados por VIH, con una edad media de 36,8'}7 anos (rango 25-46 anos) para establecer el diagnostico de CO. Se registraron las variables edad, sexo, tiempo de evolucion de la enfermedad, conducta de riesgo, numero de linfocitos CD4/'ÊL, estadio clinico y tratamiento antirretroviral. De los 200 pacientes del grupo de estudio, 157 no cumplian criterios de SIDA en el momento de la exploracion basal y a estos se les efectuo un seguimiento semestral hasta que cumplieron dichos criterios, concluyendo el estudio al final de 2001. Resultados: De los 157 pacientes seleccionados, 71 (45,2%) no presentaron CO y de estos el 28,7% evoluciono a SIDA durante el periodo de seguimiento. De los 86 (54,8%) pacientes con CO, el 48,2% evoluciono a SIDA (RR=2,71). Al trasladar el origen del estudio al ano 1997 cuando se inicio la administracion de la terapia antirretroviral de alta eficacia (TAAE), no se observaron diferencias en el porcentaje de pacientes que evolucionaron a SIDA en relacion a la existencia o no de CO en la exploracion basal. El analisis multivariante demostro que la asociacion de la variable de exposicion CO con la evolucion a SIDA no alcanzo un valor predictivo. Conclusiones: El valor pronostico a largo plazo de la CO, no se ha determinado en pacientes que reciben terapia antirretroviral de alta eficacia (TAAE). La recuperacion inmunologica y la disminucion de enfermedades oportunistas observadas tras la administracion de TAAE, hacen que muchos pacientes que alcanzaron la condicion de SIDA no cumplan en la actualidad dichos criterios, lo que obliga a renovar la propia definición del síndrome para poder evaluar marcadores de pronóstico.Objective: To determine the validity of oral candidiasis (OC) as a clinical marker of progression in patients with human immunodeficiency virus infection. Study design: In 1992, an oral examination was carried out on a group of 200 HIV-infected patients with a mean age of 36.8 ± 7 years (range 25-46 years) to establish the diagnosis of OC. The following variables were recorded: age, sex, duration of the disease, risk behaviour, CD4 lymphocyte count, clinical stage and antiretroviral treatment. Of the 200 patients in the group evaluated, 157 did not fulfil the criteria for AIDS at the time of the baseline examination; these patients constitute the study group and underwent 6-monthly follow-up until they fulfilled these criteria. The study was concluded at the end of 2001. Results: Of the 157 patients selected, 71 (45.2%) did not present OC and, of these, 28.7% progressed to AIDS during the followup period. Of the 86 (54.8%) patients with OC, 48.2% progressed to AIDS (RR= 2.71). If the start date of the study was taken as 1997, when highly active antiretroviral therapy (HAART) was introduced, no differences were found in the percentage of patients who progressed to AIDS with respect to the presence or absence of OC at the baseline examination. Multivariate analysis demonstrated that the association of the presence of OC with progression to AIDS did not reach a predictive value. Conclusions: The long-term prognostic value of OC has not been established in patients receiving highly active antiretroviral therapy (HAART). The immunological recovery and the reduction in the number of opportunistic diseases observed after the administration of HAART means that many patients who developed AIDS do not currently satisfy these criteria, making a review of the definition of the syndrome itself a necessity in order to be able to evaluate prognostic markers

Lethal and sublethal toxicity of Fipronil and Imidacloprid on Psyttalia concolor (Hymenoptera: Braconidae).

Psyttalia concolor (Szèpligeti) (Hymenoptera: Braconidae) is a koinobiont endoparasitoid of several species of tephritid (Diptera) larvae, such as Bactrocera oleae (Gmelin) and Ceratitis capitata (Wiedemann). Here, we report on the effects of imidacloprid and fipronil on P. concolor females, when different routes of exposure were evaluated: residual contact (cover and bait sprays) and via treatment of host species. Moreover, the persistence of the bait formulated compound also was studied. For each experiment, lethal (mortality) and sublethal effects (parasitization rate or longevity) were studied. Fipronil produced 100% mortality irrespective of exposure route, and it was very persistent, because 34-d-old residues still produced this high mortality rate, being as toxic or even more toxic than the reference product dimethoate. Toxicity of imidacloprid depends on the mode of exposure, although always remained less toxic than dimethoate. Imidacloprid caused high mortality or sublethal effect to the progeny in cover sprays and when applied via treated host, being harmless in bait sprays application. In conclusion, our results suggest that fipronil should not be used in the field when the parasitoid is present. On the contrary, although imidacloprid is physiologically active against females of P. concolor, ecological selectivity may result through the use of bait treatmen

Stratigraphy and chemostratigraphy of the Valanginian (pro parte) from Loma Solana, Sierra de Quípar (External Subbetic, Cehegín, Murcia)

The stratigraphy, biostratigraphy and geochemistry (C stable isotopes and RSTE trace elements) of a succession of Valanginian age outcropping in Loma Solana (External Subbetic) is presented. The succession is composed of two local sections, one cropping out to the west of Cehegín (Murcia) and another in the Garranchal gorge, to the SSW of this locality. The lithology consists of marl and marlstone rhythmically interbedded, which is typical of the Carretero Fm of the Subbetic. The ammonite zones and subzones of the middle- late early Valanginian and the complete late Valanginian, except for the lattermost part, have been identified, without any evidence of stratigraphic discontinuity between the two local sections. The δ13C curve show a similar shape to those of the same age obtained in other basins and the positive excursion of the δ13C characterizing the Weissert episode of environmental change (EECWeissert) has been identified. The RSTE, redox sensitive trace elements, analyzed do not show any particular increase as is typical of anoxic events and consequently conclude that anoxia due not exist in this part of the Subbetic basin during this EECSe presenta el estudio estratigráfico, bioestratigráfico y geoquímico de una sucesión del Valanginiense que aflora en Loma Solana (Subbético Externo). Se trata de una sección compuesta de dos secciones parciales, una de ellas levantada al oeste de Cehegín (Murcia) y la otra en el barranco del Garranchal, al SSO de dicha localidad. La litología,margas y margocalizas en alternancia rítmica, es la típica de la Fm. Carretero, a la que corresponde. Se identifican las zonas y subzonas de ammonites de la parte media-alta del Valanginiense inferior y de todo el Valanginiense superior, excepto la parte más terminal del mismo, sin que se haya denotado discontinuidad alguna entre una sección y otra. La curva de valores de δ13C muestra una forma similar a la obtenida en otras cuencas para la misma edad y en ella se puede identificar la excursión positiva del δ13C que caracteriza el episodioWeissert de cambio ambiental. Los elementos traza analizados, sensibles a cambios en las condiciones redox del medio sedimentario (elementos RSTE), no indican que hubiera condiciones anóxicas en el mismo durante este episodio de cambio ambienta

Digestibilidad y respuesta ovárica de conejas reproductoras alimentadas con dietas suplementadas con ácidos grasos poliinsaturados n-3

Aumentar el número de gazapos destetados por coneja y parto es un objetivo importante para incrementar la rentabilidad del sector cunícola industrial con efectos directos. La mejora genética de la prolificidad en las líneas de madres ha demostrado ser una estrategia eficaz para alcanzar este objetivo; sin embargo otras vías, como la influencia de diferentes fuentes de grasa en las dietas de conejas reproductoras, han sido muy poco estudiadas. Los ácidos grasos (AG) n-3 interfieren en la fisiología reproductiva porque pueden modular las enzimas involucradas en el metabolismo de las prostaglandinas y del colesterol que es el precursor de los esteroides como la progesterona (revisado en Gulliver et al., 2012). El objetivo de este trabajo es estudiar si la suplementación con AG poliinsaturados (PUFA) n-3 de las dietas de conejas durante la recría puede afectar a la tasa de ovulación y a la síntesis esteroidogénica ovárica determinada mediante las concentraciones de progesterona plasmática