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Search Results: 1 - 10 of 223882 matches for " R. Ferragut "
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Network Intrusion Detection and Visualization Using Aggregations in a Cyber Security Data Warehouse  [PDF]
Bogdan Denny Czejdo, Erik M. Ferragut, John R. Goodall, Jason Laska
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2012, DOI: 10.4236/ijcns.2012.529069
Abstract: The challenge of achieving situational understanding is a limiting factor in effective, timely, and adaptive cyber-security analysis. Anomaly detection fills a critical role in network assessment and trend analysis, both of which underlie the establishment of comprehensive situational understanding. To that end, we propose a cyber security data warehouse implemented as a hierarchical graph of aggregations that captures anomalies at multiple scales. Each node of our proposed graph is a summarization table of cyber event aggregations, and the edges are aggregation operators. The cyber security data warehouse enables domain experts to quickly traverse a multi-scale aggregation space systematically. We describe the architecture of a test bed system and a summary of results on the IEEE VAST 2012 Cyber Forensics data.
Defect Characterization in SiGe/SOI Epitaxial Semiconductors by Positron Annihilation
Ferragut R,Calloni A,Dupasquier A,Isella G
Nanoscale Research Letters , 2010,
Abstract: The potential of positron annihilation spectroscopy (PAS) for defect characterization at the atomic scale in semiconductors has been demonstrated in thin multilayer structures of SiGe (50 nm) grown on UTB (ultra-thin body) SOI (silicon-on-insulator). A slow positron beam was used to probe the defect profile. The SiO2/Si interface in the UTB-SOI was well characterized, and a good estimation of its depth has been obtained. The chemical analysis indicates that the interface does not contain defects, but only strongly localized charged centers. In order to promote the relaxation, the samples have been submitted to a post-growth annealing treatment in vacuum. After this treatment, it was possible to observe the modifications of the defect structure of the relaxed film. Chemical analysis of the SiGe layers suggests a prevalent trapping site surrounded by germanium atoms, presumably Si vacancies associated with misfit dislocations and threading dislocations in the SiGe films.
Prediction of vertical jump height. Role of mechanical impulse and leg muscle mass Predicción de la altura de salto vertical. Importancia del impulso mecánico y de la masa muscular de las extremidades inferiores
C. Ferragut,J. Cortadellas,R. Arteaga,J. A. L. Calbet
Motricidad : European Journal of Human Movement , 2010,
Abstract: The aim of this study was to find out if it is possible to predict the height of the vertical jump from kinematic, dynamometric and anthropometric variables using a multiple linear regression model. Fifty-three subjects, 21 male and 9 female volleyball players of first National categories (First National League and First League), as well as 23 Physical Education students (12 males and 11 females) participated in this study. First, the height of the flight during the performance of a "squat jump" (SJ) and "countermovement jump" (CMJ) was determined. Then, the maximal isometric strength in the squat position was assessed with the knees bent at 90o, 120o and 140o while the electromyographic activity was simultaneously recorded on the vastus lateralis with surface electrodes. The muscle mass of the lower limbs was obtained by dual-energy X-ray absorptiometry (DEXA). The positive mechanical impulse explained on its own 77% of jumping height variability. Prediction power was increased to 82% by including in the model the percentage of body mass represented by de muscle mass of the lower limbs. The inclusion of the muscle mass of the lower limbs, as a third variable, raised the prediction power to 98% of jumping height variability. The same variables allowed for a similar level of prediction during the squat jumps. KEY WORDS: Vertical jump, DEXA, muscle mass, strength. El objetivo de este estudio ha sido determinar si es posible predecir la altura de vuelo en el salto vertical a partir de variables cinemáticas, dinamométricas y antropométricas, mediante un modelo de regresión múltiple lineal. Participaron en el estudio 53 sujetos, 21 hombres jugadores de voleibol de categorías nacionales (División de Honor y Primera División) y 9 mujeres jugadoras de voleibol de División de Honor, así como 23 estudiantes de Educación Física, de los cuales 12 eran hombres y 11 mujeres. Inicialmente se determinó la altura de vuelo en saltos efectuados sin contramovimiento o "squat jumps" (SJ) y en saltos precedidos por un contramovimiento o "countermovement jumps" (CMJ). Además, se determinó la fuerza isométrica máxima (FIM) en posición de semisentadillla, con las rodillas flexionadas a 90o, 120o y 140o , simultáneamente se tomaron medidas de la actividad electromiográfica del vasto externo del cuádriceps. La masa muscular de las extremidades inferiores se midió mediante absociometría fotónica dual de rayos X (DEXA). El impulso positivo explicó por sí solo un 77% de la variabilidad en altura de vuelo. La variable anterior combinada con el porcentaje de masa corporal representado
Analysis of electron-positron momentum spectra of metallic alloys as supported by first-principles calculations
P. Folegati,I. Makkonen,R. Ferragut,M. J. Puska
Physics , 2006, DOI: 10.1103/PhysRevB.75.054201
Abstract: Electron-positron momentum distributions measured by the coincidence Doppler broadening method can be used in the chemical analysis of the annihilation environment, typically a vacancy-impurity complex in a solid. In the present work, we study possibilities for a quantitative analysis, i.e., for distinguishing the average numbers of different atomic species around the defect. First-principles electronic structure calculations self-consistently determining electron and positron densities and ion positions are performed for vacancy-solute complexes in Al-Cu, Al-Mg-Cu, and Al-Mg-Cu-Ag alloys. The ensuing simulated coincidence Doppler broadening spectra are compared with measured ones for defect identification. A linear fitting procedure, which uses the spectra for positrons trapped at vacancies in pure constituent metals as components, has previously been employed to find the relative percentages of different atomic species around the vacancy [A. Somoza et al. Phys. Rev. B 65, 094107 (2002)]. We test the reliability of the procedure by the help of first-principles results for vacancy-solute complexes and vacancies in constituent metals.
Inteligencia emocional, bienestar personal y rendimiento académico en preadolescentes
Marta Ferragut,Alfredo Fierro
Revista Latinoamericana de Psicología , 2012,
Abstract: El objetivo principal de este estudio es el análisis de la relación entre la inteligencia emocional y el bienestar personal y su posible predicción del rendimiento académico. Los participantes fueron 166 estudiantes de último ciclo de primaria de entre 9 y 12 a os. Para evaluar la inteligencia emocional, se empleó el Trait Meta-Mood Scale (TMMS- 24) de Salovey y colaboradores (1995), para el bienestar personal se ha aplicado la Escala Eudemon y el ítem General de Felicidad (Fierro, 2006) y para el rendimientoacadémico se registraron distintas variables, donde la principal fue la nota media. Los resultados mostraron la existencia de correlaciones significativas entre bienestar e inteligencia emocional, así como entre rendimiento académico y bienestar, no así entre inteligencia emocional y rendimiento académico. Además, el análisis de regresión múltiple muestra una recta de regresión donde el único predictor para nota media es el bienestar. Estos resultados indican relación entre bienestar e inteligencia emocional y la importancia de estos constructos psicológicos para el logro académico.
Nonparametric Bayesian Modeling for Automated Database Schema Matching
Erik M. Ferragut,Jason Laska
Computer Science , 2015,
Abstract: The problem of merging databases arises in many government and commercial applications. Schema matching, a common first step, identifies equivalent fields between databases. We introduce a schema matching framework that builds nonparametric Bayesian models for each field and compares them by computing the probability that a single model could have generated both fields. Our experiments show that our method is more accurate and faster than the existing instance-based matching algorithms in part because of the use of nonparametric Bayesian models.
HackAttack: Game-Theoretic Analysis of Realistic Cyber Conflicts
Erik M. Ferragut,Andrew C. Brady,Ethan J. Brady,Jacob M. Ferragut,Nathan M. Ferragut,Max C. Wildgruber
Computer Science , 2015,
Abstract: Game theory is appropriate for studying cyber conflict because it allows for an intelligent and goal-driven adversary. Applications of game theory have led to a number of results regarding optimal attack and defense strategies. However, the overwhelming majority of applications explore overly simplistic games, often ones in which each participant's actions are visible to every other participant. These simplifications strip away the fundamental properties of real cyber conflicts: probabilistic alerting, hidden actions, unknown opponent capabilities. In this paper, we demonstrate that it is possible to analyze a more realistic game, one in which different resources have different weaknesses, players have different exploits, and moves occur in secrecy, but they can be detected. Certainly, more advanced and complex games are possible, but the game presented here is more realistic than any other game we know of in the scientific literature. While optimal strategies can be found for simpler games using calculus, case-by-case analysis, or, for stochastic games, Q-learning, our more complex game is more naturally analyzed using the same methods used to study other complex games, such as checkers and chess. We define a simple evaluation function and ploy multi-step searches to create strategies. We show that such scenarios can be analyzed, and find that in cases of extreme uncertainty, it is often better to ignore one's opponent's possible moves. Furthermore, we show that a simple evaluation function in a complex game can lead to interesting and nuanced strategies.
Aspectos contemporaneos da interven??o coronária percutanea no tratamento eletivo de estenoses localizadas no tronco n?o-protegido da artéria coronária esquerda
Attizzani, Guilherme Ferragut;Bezerra, Hiram G.;
Revista Brasileira de Cardiologia Invasiva , 2010, DOI: 10.1590/S2179-83972010000400017
Abstract: percutaneous coronary intervention (pci) in the non-protected left main coronary artery (lm) was until recently considered a harmful practice for individuals eligible for coronary artery bypass grafting (cabg), a gold standard in the treatment of this disease. this concept was based on the high rates of major adverse cardiac events in patients treated with balloon angioplasty and later on, in patients treated with bare-metal stents. more recently, the introduction of drug-eluting stents in our daily clinical practice promoted marked reductions in the rates of restenosis and major adverse cardiac events in patients treated by pci. the good results obtained led to a review of the pci guidelines, which now consider this treatment as a feasible option, classifying the level of indication according to clinical complexity as well as the coronary anatomy to be approached. however, despite this significant advance, it is important to highlight some aspects: treatment of the distal bifurcation is associated to a worse prognosis than ostial or midshaft lesions and the best approach in this situation seems to be the t-provisional technique. so far, substantial differences have not been established for different drug-eluting stents and intravascular imaging techniques should be strongly encouraged to guide their implant. finally, patient assessment and selection for the procedure should be guided by scores based on clinical and angiographic characteristics.
Análisis Cualitativo de la Personalidad de una Actriz: Estudio de Caso y Trastorno de Personalidad Límite
Ortiz-Tallo,Margarita; Ferragut,Marta;
Clínica y Salud , 2010,
Abstract: this paper analyzes the life story of a famous actress now deceased. data are collected through studies and reading of documents and biographies. a retrospective case study through documents is presented. we conclude the possible existence of a reactive attachment disorder in childhood and a borderline personality disorder in adulthood and is justified. finally, characteristics of borderline personality disorder are explained and hypothesis related disorder are commented.
Efeito de diferentes níveis de enriquecimento por fósforo sobre a estrutura da comunidade perifítica em represa oligotrófica tropical (S?o Paulo, Brasil)
Ferragut, Carla;Bicudo, Denise de Campos;
Brazilian Journal of Botany , 2009, DOI: 10.1590/S0100-84042009000300015
Abstract: nutrient diffusing substrata (nds) were used to determine the effect of added phosphorus on the periphyton development in a shallow reservoir (lago do iag, pefi, s?o paulo). three treatments (n = 2) were designed: control (without phosphorous addition) and two levels of phosphorus addition (p1 = 0.1 m and p2 = 0.5 m kh2po4). nds surface was covered with a 20 μm mesh cloth for periphyton growth. samplings were carried at 15, 20, 25 and 30 days of colonization. biomass accumulation (organic matter, chlorophyll-a, total algal biovolume) and total algal density did not show significant response to nutrient addition. seven species of chlorophytes and one of diatoms were closely associated to p availability. periphyton nutrient status (p%, n%, n:p) demonstrated p-limitation as well as reinforced periphyton p retention capacity. periphyton attributes were more sensible to p enrichment than to the different addition levels, indicating further n-limitation. comparison with previous data indicated temporal (1996-2002) increase in the reservoir phosphorus availability, although p-limitation is still prevalent. periphyton, on the basis of its nutrient status and species structure, was sensible to temporal shift on phosphorus availability and p-addition, reinforcing its potential as an evaluating tool for early signs of eutrophication.
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