Multiplexing of encrypted data using fractal masks

This paper was published in OPTICS LETTERS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.37.002895. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under lawIn this Letter, we present to the best of our knowledge a new all-optical technique for multiple-image encryption and multiplexing, based on fractal encrypting masks. The optical architecture is a joint transform correlator. The multiplexed encrypted data are stored in a photorefractive crystal. The fractal parameters of the key can be easily tuned to lead to a multiplexing operation without cross talk effects. Experimental results that support the potential of the method are presented.This research was performed under grants TWAS-UNESCO Associateship Scheme at Centres of Excellence in the South, CONICET No. 0863 (Argentina), ANCYT PICT 1167 (Argentina), and Facultad de Ingenieria, Universidad Nacional de La Plata No. 11/I125 (Argentina), Sostenibilidad 2011-2012, and CODI (Universidad de Antioquia-Colombia). W. D. Furlan and J. A. Monsoriua acknowledge financial support from Ministerio de Economia y Competitividad (grant FIS2011-23175), Generalitat Valenciana (grant PROMETEO2009-077), and Universitat Politecnica de Valencia (grants PAID-05-11 and PAID-02-11), Spain.Barrera, J.; Tebaldi, M.; Amaya, D.; Furlan, W.; Monsoriu Serra, JA.; Bolognini, NA.; Torroba, RD.... (2012). Multiplexing of encrypted data using fractal masks. Optics Letters. 37(14):2895-2897. doi:10.1364/OL.37.002895S289528973714Refregier, P., & Javidi, B. (1995). Optical image encryption based on input plane and Fourier plane random encoding. Optics Letters, 20(7), 767. doi:10.1364/ol.20.000767Matoba, O., & Javidi, B. (1999). Encrypted optical memory system using three-dimensional keys in the Fresnel domain. Optics Letters, 24(11), 762. doi:10.1364/ol.24.000762Unnikrishnan, G., Joseph, J., & Singh, K. (2000). Optical encryption by double-random phase encoding in the fractional Fourier domain. Optics Letters, 25(12), 887. doi:10.1364/ol.25.000887Nomura, T. (2000). Polarization encoding for optical security systems. Optical Engineering, 39(9), 2439. doi:10.1117/1.1288369Tebaldi, M., Furlan, W. D., Torroba, R., & Bolognini, N. (2009). Optical-data storage-readout technique based on fractal encrypting masks. Optics Letters, 34(3), 316. doi:10.1364/ol.34.000316Situ, G., & Zhang, J. (2005). Multiple-image encryption by wavelength multiplexing. Optics Letters, 30(11), 1306. doi:10.1364/ol.30.001306Liu, Z., & Liu, S. (2007). Double image encryption based on iterative fractional Fourier transform. Optics Communications, 275(2), 324-329. doi:10.1016/j.optcom.2007.03.039Hwang, H.-E., Chang, H. T., & Lie, W.-N. (2009). Multiple-image encryption and multiplexing using a modified Gerchberg-Saxton algorithm and phase modulation in Fresnel-transform domain. Optics Letters, 34(24), 3917. doi:10.1364/ol.34.003917Matoba, O., & Javidi, B. (1999). Encrypted optical storage with angular multiplexing. Applied Optics, 38(35), 7288. doi:10.1364/ao.38.007288Fredy Barrera, J., Henao, R., Tebaldi, M., Torroba, R., & Bolognini, N. (2006). Multiplexing encryption–decryption via lateral shifting of a random phase mask. Optics Communications, 259(2), 532-536. doi:10.1016/j.optcom.2005.09.027Henao, R., Rueda, E., Barrera, J. F., & Torroba, R. (2010). Noise-free recovery of optodigital encrypted and multiplexed images. Optics Letters, 35(3), 333. doi:10.1364/ol.35.000333Barrera, J. F., Henao, R., Tebaldi, M., Torroba, R., & Bolognini, N. (2006). Multiple image encryption using an aperture-modulated optical system. Optics Communications, 261(1), 29-33. doi:10.1016/j.optcom.2005.11.055Mosso, F., Barrera, J. F., Tebaldi, M., Bolognini, N., & Torroba, R. (2011). All-optical encrypted movie. Optics Express, 19(6), 5706. doi:10.1364/oe.19.005706Monsoriu, J. A., Saavedra, G., & Furlan, W. D. (2004). Fractal zone plates with variable lacunarity. Optics Express, 12(18), 4227. doi:10.1364/opex.12.00422

Arthropod pests and their management, natural enemies and flora visitors associated with castor (Ricinus communis), a biofuel plant: a review.

Interest in bioenergetic crops, such as the castor oil plant Ricinus communis (Euphorbiaceae), for production of biodiesel has increased in recent years. In this paper, phytophagous arthropods, their natural enemies and floral visitors associated with this plant in the world are reviewed. Despite its insecticidal properties, arthropods have been reported feeding on R. communis plants. The arthropod pests of R. communis damage all parts of the plant, including the seeds, where some toxic compounds are even more concentrated. In the scientific databases, we found reports of 193 arthropods associated to R. communis in different parts of the world. This information obtained in the scientific databases was concentrated in a database and analyzed according to the coevolutive hypothesis, which allows us to predict that the greatest wealth and abundance of phytogenic arthropods is found in the center of origin by R. communis. According to this review, Achaea janata, Spodoptera litura, Edwardsiana flavescens, Liriomyza trifolii, L. sativae, Spilosoma obliqua, Cogenethes punctiferalis, Oxyrhachis taranda, and Helicoverpa armigera are the most devastating pests in Asia. In Africa, Agrotis ipsilon, S. exigua, Nezara viridula, Trialeurodes ricini, and Tetranychus urticae were mentioned as the most important. In Central and South-America, Phyllophaga sp., Agrietes sp., Erinnyis ello, N. viridula, Corythucha gossypii, Falconia antioquiana, and S. marima are reported as pests of economic importance. The most commonly reported natural enemies of some of these arthropod pests were species of Bacillus thuringiensis, B. cereus, B. popilliae, Trichogramma achaeae, T. chilonis, T. minutum, T. australicum, T. dendrolimi, T. pretiosum, T. evanescens, Microplitis rufiventris, M. maculipennis, M. ophiusae, Telenomus remus, T. proditor, Stethorus siphonulus and S. histrio. Apis mellifera is recorded as the main insect pollinator of R. communis. Pest management methods used against the arthropod pests of R. communis include biological, ethological, mechanical, cultural, genetic, and chemical control

Patrones de actividad física en una muestra española

Este trabajo pretende describir la frecuencia y las actividades físicas y deportivas que realiza una muestra de hombres y mujeres de la provincia de Granada (lo que denominamos perfil de actividad física). Nos interesaba además, ver la frecuencia de práctica de actividades físicas y deportivas que cada uno de los sujetos de la muestra ha realizado a lo largo de su vida (niveles de actividad física). Para ello seleccionamos una muestra de 625 sujetos de ambos sexos, de diferentes niveles culturales y de práctica de actividades físicas y deportivas. Los resultados indican diferencias entre grupos en la práctica de actividades físicas y que los sujetos que en la actualidad realizan más actividad física son también los que más actividad física han realizado a lo largo de su vidaThis work attempted to describe the frequency and type of physical and sports activities in a sample of men and women in the province of Granada (which we call profile of physical activity). We were also interested in seeing the frequency of physical and sports activities for each of the subjects in our sample throughout the course of their lives (levels of physical activity). The sample consisted of 625 men and women of varying socio-cultural levels and different levels of physical and sports activities. The results show between group differences in the practice of physical activities and that those subjects who currently engage in higher levels of physical activity are those who engage in higher levels through the course of their live

Carbones colombianos: clasificación y caracterización termoquímica para aplicaciones energéticas

ResumenLa relación reservas/producción de carbón en Colombia ronda los 91 años. Para aprovechar tal disponibilidad del carbón mediante tecnologías de alta eficiencia, es necesario contar con la adecuada caracterización de los diferentes carbones. En este trabajo se analizaron 10 muestras de carbones colombianos con diferentes rangos y calidad, procedentes de diferentes locaciones geográficas. Cada muestra se caracterizó según su análisis próximo, análisis último, análisis termogravimétrico (TGA) y poder calorífico. Se estableció el rango o calidad de cada muestra según diferentes métodos estandarizados, incluyendo normas ASTM, diagramas de Van Kleveler, método gráfico de Parr y la norma ISO 11760-2005. Adicionalmente se determinó la reactividad de las muestras a través de análisisTGA y análisis térmico diferencial (DTG). Se encontró que los carbones de mayor rango o calidad no necesariamente resultan ser los más reactivos para aplicaciones energéticas, ya que a mayor proporciónde carbono fijo, la liberación de material volátil tiende a ser más lenta, disminuyendo su capacidad de uso y transformación en procesos termoquímicos. Palabras clave: carbones colombianos, análisis próximo, análisis último, reactividad, rango, aprovechamiento energético.    Colombian coals: classification and thermochemical characterization for energy applications  Abstract Colombian coal reserves/production ratio is around 91 years. The challenge is to exploit the availability of coal in Colombia by means of higher efficiency technologies, it is necessary to characterize the different coals properly. In this work ten Colombian samples of coal with different rank and quality were analyzed. The samples are from different regions around the country. Each sample was characterized according to proximate and ultimate analysis, as well as thermogravimetric analysis and heating value. For each coal sample was assessed its rank or quality according to different standardized methods, i.e., ASTM standard, Van Kleveler diagram, Parr method and ISO 11760-2005 standard. Moreover, the reactivity of each sample was determined by means of thermogravimetric and its differential thermal analyses. It was found that the coals with the higher rank are not necessarily the more reactive fuels for energy use. This is due to the coals, with higher fixed carbon, release the volatile matter slowly; therefore, its use capacity and its thermochemical transformation decreases. Keywords: colombian coals, proximate and ultimate analysis, reactivity, coal Rank, energy use.    Carvões colombianos: classificação e caracterização para aplicações de energia termoquímica  ResumoA relação reservas / produção de carvão na Colômbia é de cerca de 91 anos. Procurando explorar a disponibilidade de carvão na Colômbia, por meio de tecnologias de eficiência mais elevados, é necessário ter a caracterização adequada dos diferentes carvões. Neste trabalho foram analisadas dez amostras de carvão da Colômbia com diferentes categoria e qualidade. As amostras são provenientes de diferentes regiões do país. Cada amostra foi caracterizada de acordo com a análise imediata e definitiva, bem como a análise termogravimétrica (TGA) e valor calórico. Para cada amostra de carvão foi avaliada a sua categoria ou qualidade de acordo com diferentes métodos padrão, incluindo ASTM, diagramas Van Kleveler, método Parr e padrão ISO 11760-2005. Além disso, a reatividade de cada amostra foi determinada utilizando TGA e suas análises térmicas diferenciais. Verificou-se que as brasas com o posto mais alto não são necessariamente os combustíveis mais reativas para aplicações de energia, porque com maior proporção de carbono fixo, a matéria volátil que é liberado mais lentamente, portanto, a sua capacidade de uso e sua transformação termoquímica tende a ser mais lenta. Palabras-chave: carvão da Colômbia, análise imediata e definitiva, reatividade, carvão rank, utilização de energia.    Cita: Barrera Zapata R, Perez Bayer JF, Salazar Jiménez C. Carbones colombianos: clasificación y caracterización termoquímica para aplicaciones energéticas. rev.ion. 2014;27(2):43-54

Carbones colombianos: clasificación y caracterización termoquímica para aplicaciones energéticas

ResumenLa relación reservas/producción de carbón en Colombia ronda los 91 años. Para aprovechar tal disponibilidad del carbón mediante tecnologías de alta eficiencia, es necesario contar con la adecuada caracterización de los diferentes carbones. En este trabajo se analizaron 10 muestras de carbones colombianos con diferentes rangos y calidad, procedentes de diferentes locaciones geográficas. Cada muestra se caracterizó según su análisis próximo, análisis último, análisis termogravimétrico (TGA) y poder calorífico. Se estableció el rango o calidad de cada muestra según diferentes métodos estandarizados, incluyendo normas ASTM, diagramas de Van Kleveler, método gráfico de Parr y la norma ISO 11760-2005. Adicionalmente se determinó la reactividad de las muestras a través de análisisTGA y análisis térmico diferencial (DTG). Se encontró que los carbones de mayor rango o calidad no necesariamente resultan ser los más reactivos para aplicaciones energéticas, ya que a mayor proporciónde carbono fijo, la liberación de material volátil tiende a ser más lenta, disminuyendo su capacidad de uso y transformación en procesos termoquímicos. Palabras clave: carbones colombianos, análisis próximo, análisis último, reactividad, rango, aprovechamiento energético.    Colombian coals: classification and thermochemical characterization for energy applications  Abstract Colombian coal reserves/production ratio is around 91 years. The challenge is to exploit the availability of coal in Colombia by means of higher efficiency technologies, it is necessary to characterize the different coals properly. In this work ten Colombian samples of coal with different rank and quality were analyzed. The samples are from different regions around the country. Each sample was characterized according to proximate and ultimate analysis, as well as thermogravimetric analysis and heating value. For each coal sample was assessed its rank or quality according to different standardized methods, i.e., ASTM standard, Van Kleveler diagram, Parr method and ISO 11760-2005 standard. Moreover, the reactivity of each sample was determined by means of thermogravimetric and its differential thermal analyses. It was found that the coals with the higher rank are not necessarily the more reactive fuels for energy use. This is due to the coals, with higher fixed carbon, release the volatile matter slowly; therefore, its use capacity and its thermochemical transformation decreases. Keywords: colombian coals, proximate and ultimate analysis, reactivity, coal Rank, energy use.    Carvões colombianos: classificação e caracterização para aplicações de energia termoquímica  ResumoA relação reservas / produção de carvão na Colômbia é de cerca de 91 anos. Procurando explorar a disponibilidade de carvão na Colômbia, por meio de tecnologias de eficiência mais elevados, é necessário ter a caracterização adequada dos diferentes carvões. Neste trabalho foram analisadas dez amostras de carvão da Colômbia com diferentes categoria e qualidade. As amostras são provenientes de diferentes regiões do país. Cada amostra foi caracterizada de acordo com a análise imediata e definitiva, bem como a análise termogravimétrica (TGA) e valor calórico. Para cada amostra de carvão foi avaliada a sua categoria ou qualidade de acordo com diferentes métodos padrão, incluindo ASTM, diagramas Van Kleveler, método Parr e padrão ISO 11760-2005. Além disso, a reatividade de cada amostra foi determinada utilizando TGA e suas análises térmicas diferenciais. Verificou-se que as brasas com o posto mais alto não são necessariamente os combustíveis mais reativas para aplicações de energia, porque com maior proporção de carbono fixo, a matéria volátil que é liberado mais lentamente, portanto, a sua capacidade de uso e sua transformação termoquímica tende a ser mais lenta. Palabras-chave: carvão da Colômbia, análise imediata e definitiva, reatividade, carvão rank, utilização de energia.    Cita: Barrera Zapata R, Perez Bayer JF, Salazar Jiménez C. Carbones colombianos: clasificación y caracterización termoquímica para aplicaciones energéticas. rev.ion. 2014;27(2):43-54

The deep inferior epigastric artery perforator flap: a review

Breast cancer is recognized worldwide as a major health problem among women due to its high incidence and high mortality and morbidity rates. Breast reconstruction is an approach of great value for those patients who underwent mastectomy, impacting their quality of life and psychological stress. The deep inferior epigastric artery perforator (DIEP) flap was described as the preferred graft for breast reconstruction with an autologous flap by surgeons because it represented a decrease in complications for the time and obtained better results. DIEP flap reconstruction requires microsurgical skills as well as continuous monitoring of the patient to identify and resolve possible associated complications.

-

Objetivo: determinar propiedades psicométricas de los instrumentos desarrollados por la OPS para evaluar  la calidad y la efectividad potencial de material educativo. Materiales y métodos: se utilizaron instrumentos  diseñados por la OPS para evaluar la calidad de material educativo en salud, diseñado durante el primer  semestre del 2010. La evaluación fue realizada por grupos de usuarios del material, así: para material  audiovisual, n=74; material impreso, n=116; material sonoro, n=37; material visual: n=71. Para cada  instrumento se evaluó la factoriabilidad mediante las pruebas de Kaiser-Meyer-Olkin y de esfericidad de  Bartlett. Posteriormente, se determinó la consistencia interna y estructura factorial del instrumento  mediante la estimación del alfa de Cronbach, y el análisis factorial por el método de extracción de  componentes principales. Resultados: todos los instrumentos fueron factorizables. El alfa de Cronbach para  material audiovisual fue 0,687; la extracción de ejes principales reportó cuatro factores. Para material  impreso: alfa de Cronbach de 0,83; la extracción de componentes principales arrojó un solo factor  Cronbach  = 0,73 y se extrajeron tres componentes principales. Para el material visual se encuentra alfa de Cronbach =  0,66 con tres componentes principales. Conclusiones: los instrumentos diseñados por la OPS para evaluar  material educativo constituyen una herramienta confiable para evaluar los criterios de atracción,  entendimiento, identificación y aceptación; se hace necesario profundizar en el análisis estructural de estos;  no evalúan el criterio de inducción a la acción que otros autores referencian.Objective: to determine psychometric properties of the instruments developed by PAHO to assess quality  and potential effectiveness of educational material. Materials and methods: instruments designed by PAHO  to assess the quality of health educational materials designed during the first semester 2010 were used. The  evaluation was carried out through materials user groups as follows: audiovisual material, n = 74; printed  material, n = 116; audio recordings, n = 37; visual material, n = 71. Factorability was evaluated for each one of  the instruments by using Kaiser -Meyer-Olkin`s test and sphericity was evaluated with Bartlett’s test. Internal  consistency and factorial structure of the instrument were determined later using Cronbach’s alpha estimate  and the factorial analysis was carried out using the main components extraction method. Results: all  instruments were factorable. Cronbach’s alpha for audiovisual material was 0.687; extraction of principal  axes reported 4 factors. For printed material: 0.83Cronbach’s alpha; the extraction of principal components  showed a single factor which explains 45.1% of the variance. In the audio material it was found 0.73  Cronbach`s alpha and three major components were extracted. For visual material Cronbach’s alpha is = 0.66  with three main components. Conclusions: the instruments designed by PAHO to assess educational  materials are a reliable tool for assessing the attraction, understanding, identifying and accepting criteria;  however, it is necessary to go deeper in their structural analysis. The do not assess the induction to action  criterion referenced by other authors

Variability estimation in resistive switching devices, a numerical and kinetic Monte Carlo perspective

Acknowledgments The authors thank the support of the Spanish Ministry of Science, Innovation and Universities and the FEDER program through projects TEC2017-84321-C4-1-R, TEC2017-84321-C4-3-R, and projects A.TIC.117.UGR18, IE2017-5414 and B.TIC.624.UGR20 funded by the Consejería de Conocimiento, Investigación y Universidad, Junta de Andalucía (Spain) and the FEDER program. Funding for open access charge: Universidad de Granada/CBUAWe have analyzed variability in resistive memories (Resistive Random Access Memories, RRAMs) making use of advanced numerical techniques to process experimental measurements and simulations based on the kinetic Monte Carlo technique. The devices employed in the study were fabricated using the TiN/Ti/HfO2/W stack. The switching parameters were obtained making use of new developed extraction methods. The appropriateness of the advanced parameter extraction methodologies has been checked by comparison to kinetic Monte Carlo simulations; in particular, the reset and set events have been studied and detected. The data obtained were employed to shed light on the resistive switching operation and the cycle-to-cycle variability. It has been shown that variability depends on the numerical technique employed to obtain the set and reset voltages, therefore, this issue must be taken into consideration in RS characterization and modeling studies. The proposed techniques are complementary and depending on the technology and the curves shape the features of a particular method could make it to be the most appropriate.Spanish Ministry of Science, Innovation and Universities and the FEDER program through projects TEC2017-84321-C4-1-R, TEC2017-84321-C4-3-RConsejería de Conocimiento, Investigación y Universidad, Junta de Andalucía (Spain) and the FEDER program, projects A.TIC.117.UGR18, IE2017-5414 and B.TIC.624.UGR20Funding for open access charge: Universidad de Granada/CBU

Secondary Infall in the Seyfert\u27s Sextet: A Plausible Way out of the Short Crossing Time Paradox

We used integral field spectroscopy from CALIFA DR3 and multiwavelength publicly available data to investigate the star formation histories of galaxies in the Seyfert\u27s Sextet (SS; HCG 79). The galaxies H79a, H79b, H79c, and H79f have low star formation rates despite showing strong signs of interaction. By exploring their individual specific star formation histories, we identified three earlier episodes of strong star formation common to these four galaxies. We use the last two episodes as markers of the epochs when the galaxies were crossing. We suggest that after the first turnaround, initially gas-rich galaxies crossed for the first time, consuming most of their gas. Hence, after the second turnaround most mergers from second crossings would be mixed or dry. The exception would be gas-rich galaxies intruding for the first time. Therefore, we suggest that SS galaxies have survived one crossing during a Hubble time. Strong Balmer absorption lines and the presence of counter-rotating disks provide independent bounds to the second and first crossing, respectively. This scenario provides a plausible way out of the short crossing time paradox