Efecto de la distribución de defectos en la conductividad térmica en películas delgadas de SrTiO3

Unos de los compuestos inorgánicos más estudiados a día de hoy en las ciencias del estado sólido son las perovskitas. Estos compuestos, cuya fórmula general es MNX3, tienen una gran aplicabilidad en componentes electrónicos como las memorias RAM o en celdas solares. En el presente trabajo se han fabricado películas delgadas -de espesores próximos a los 25 nm- de SrTiO3 (STO) sobre sustratos de SrTiO3 dopado con Nb (Nb:STO) mediante el método físico Deposición por Láser Pulsado (PLD). La caracterización estructural de las películas delgadas incluye estudios de difracción de rayos X obteniendo el espesor de dichas películas con las ecuaciones de Laue. En contraste con otro tipo de materiales, las películas fabricadas en el presente trabajo tienen un comportamiento no-óhmico de Resistive Switching para las cuales se definieron estados de alta (HRS) y baja resistencia eléctrica (LRS). Para dichos estados se consiguió medir una variación en la conductividad térmica de uno con respecto a la del otro utilizando técnicas de termorreflectancia. La conclusión fundamental de este trabajo es que el fenómeno de Resistive Switching afecta a la conductividad térmica de las películas delgadas de STO definiendo así el Thermal Resistive Switching.One of the most studied inorganic compounds nowadays in solid state science are perovskites. Theese compounds, which general formula is MNX3, have important applications such as electronic devices like RAM memories or solar cells. In this work SrTiO3 (STO) thin films -thicknesses around 25 nm- were synthesized by Pulsed Laser Deposition in Nb doped SrTiO3 (Nb:STO). Thin structural characterization of this thin films included x-ray diffraction techniques obtaining, therefore, the thicknesses of this films using Laue equations. In contrast with other materials, STO synthesized in this project films had a nonohmic Resistive Rwitching behaviour in which we defined a high (HRS) and a low electric resistance state (LRS). For those electric resistance states, two thermal conductivity states were distinguished using thermoreflectance techniques. The main conclussion of this work is that the Resistive Switching phenomena affects directly thermal conductivity defining, therefore, a Thermal Resistive Switching.Uns dos compostos inorgánicos máis estudados a día de hoxe nas ciencias do estado sólido son as perovskitas. Estes compostos, cuxa fórmual xeral é MNX3, teñen unha grande aplicabilidade en componentes electrónicos como as memorias RAM ou celas solares. No presente traballo fabricáronse películas delgadas -de espesores próximos aos 25 nm- de SrTiO3 (STO) sobre sustratos de SrTiO3 dopado con Nb (Nb:STO) mediante o método físico Deposición por Láser Pulsado(PLD).A caracterización estrutural das películas delgadas inclúe estudos de difracción de raios X obtendo o espesor de ditas películas cas ecuacións de Laue. En contraste con outro tipo de materiais, as películas delgadas fabricadas no presente proxecto teñen un comportamento non-óhmico de Resistive Switching para as cales definíronse estados de alta (HRS) e baixa resistencia eléctrica (LRS). Para ditos estados conseguiuse medir unha variación na conductividade térmica dun con respecto do outro empregando técnicas de termorreflectancia. A conclusión principal do proxecto é que o fenómeno de Resistive Switching afecta á conductividade térmica das películas delgadas de STO definindo así o Thermal Resistive Switching

A New Edit Distance for Fuzzy Hashing Applications

7 páginas, 5 tablas, 2 algoritmos. Comunicación presentada en: The 2015 World Congress in Computer Science, Computer Engineering, and Applied Computing (WORLDCOMP'15). The 2015 International Conference on Security and Management (SAM'15), Las Vegas, USA, July 27 - 30Similarity preserving hashing applications, also known as fuzzy hashing functions, help to analyse the content of digital devices by performing a resemblance comparison between different files. In practice, the similarity matching procedure is a two-step process, where first a signature associated to the files under comparison is generated, and then a comparison of the signatures themselves is performed. Even though ssdeep is the best-known application in this field, the edit distance algorithm that ssdeep uses for performing the signature comparison is not well-suited for certain scenarios. In this contribution we present a new edit distance algorithm that better reflects the similarity of two strings, and that can be used by fuzzy hashing applications in order to improve their results.This work has been partially supported by Comunidad de Madrid (Spain) under the project S2013/ICE-3095-CM (CIBERDINE) and by Ministerio de Economía y Com- petitividad (Spain) under the grant TIN2014-55325-C2-1-R (ProCriCiS).Peer reviewe

A Comparison of the Standardized Versions of ECIES

Elliptic Curve Cryptography (ECC) can be used as a tool for encrypting data, creating digital signatures or performing key exchanges. In relation to encryption, the Elliptic Curve Integrated Encryption Scheme (ECIES) is the best known scheme based on ECC, and as such it has been included in several cryptographic standards. In the present work, we provide an extensive review and comparison of the versions of ECIES included in documents from ANSI, IEEE, ISO/IEC, and SECG, highlighting the main differences between them that can prevent implementations of ECIES from being fully interoperable.This work has been partially supported by Ministerio de Ciencia e Innovación (Spain), under the grant TEC2009-13964-C04-02, and Ministerio de Industria, Turismo y Comercio (Spain), in collaboration with CDTI and Telefónica I+D, under the project Segur@ CENIT-2007 2004.Peer reviewe

An Asynchronous P300-Based Brain-Computer Interface Web Browser for Severely Disabled People

This paper presents an electroencephalo- graphic (EEG) P300-based brain–computer interface (BCI) Internet browser. The system uses the “odd-ball” row-col paradigm for generating the P300 evoked potentials on the scalp of the user, which are immediately processed and translated into web browser commands. There were previous approaches for controlling a BCI web browser. However, to the best of our knowledge, none of them was focused on an assistive context, failing to test their applications with a suitable number of end users. In addition, all of them were synchronous applications, where it was necessary to introduce a “read-mode” command in order to avoid a continuous command selection. Thus, the aim of this study is twofold: 1) to test our web browser with a population of multiple sclerosis (MS) patients in order to assess the usefulness of our proposal to meet their daily communication needs; and 2) to overcome the aforementioned limitation by adding a threshold that discerns between control and non-control states, allowing the user to calmly read the web page without undesirable selections. The browser was tested with sixteen MS patients and five healthy volunteers. Both quantitative and qualitative metrics were obtained. MS participants reached an average accuracy of 84.14%, whereas 95.75% was achieved by control subjects. Results show that MS patients can successfully control the BCI web browser, improving their personal autonom

Comparison of Chemical and Mechanical Surface Treatments on Metallic Precision Spheres for Using as Optical Reference Artifacts

[EN] The improvement of industrial manufacturing processes requires measurement procedures and part inspection tasks to be faster and faster while remaining effective. In this sense, the capabilities of noncontact measuring systems are of great help, not only because of the great amount of data they provide but also for the ease of the integration of these systems as well as their automation, minimising the impact on the industry. This work presents a comparative study on the influence of two surface treatments performed on low-cost, high-precision metallic spheres on the suitability of these spheres to be used as artefacts for the calibration of optical sensors, specifically laser triangulation sensors. The first surface treatment is sandblasting (a mechanical process), whose effect has been studied and presented in previous work. The second treatment focused on in this paper is acid etching (a chemical process). The comparison has been performed by evaluating the same metrological characteristics on two identical groups of spheres of similar type (diameter and accuracy), each of which was subjected to a different treatment. It was necessary to obtain the reference values of the metrological parameters with high accuracy, which involved measuring the spheres with a coordinate measuring machine (CMM) by contact probing. Likewise, spheres were scanned by a laser triangulation sensor mounted on the same CMM. The results derived from both the contact and laser measurements and before and after treating the surfaces were used to compare four parameters: point density, sphere diameter, sphere form deviation, and standard deviation of the best-fit sphere to the corresponding point cloud. This research has revealed that acid etching produces better optical qualities on the surfaces than the mirror-like original ones, thus enhancing the laser sensor capturing ability. However, such chemical etching has affected the metrological characteristics of the spheres to a greater extent than that produced by sandblasting. This difference is due to the variability of the chemical etching, caused by the high aggressiveness of the acid, which makes the process very sensitive to the time of exposure to the acid and the orientations of the spheres in the bath.SIUniversity Institute of Industrial Technology of Asturias, IUTA, through the research project ref. SV-21-GIJON-1-06

El perfeccionamiento de los orientadores en ejercicio en el contexto de la reforma: una cuestión pendiente

La formación de los orientadores que actualmente componen los diferentes servicios institucionales de orientación en España es una exigencia de la dinámica de cambio que ha puesto en marcha la Reforma: exigencia desatendida, a excepción del territorio MEC. Las necesidades deformación de los orientadores necesitan ser evaluadas sistemáticamente para vertebrar planes deformación. Una evaluación de estas necesidades ha sido realizada entre los profesionales de la orientación en Andalucía con el objeto de obtener su percepción/valoración sobre la formación inicial que recibieron para la incorporación al puesto de trabajo, sus ámbitos de carencias formativas, los intereses deformación específicos del colectivo y la viabilidad de una colaboración con la Universidad en un plan deformación. Los resultados de la investigación presentan una situación en la que los profesionales de la orientación de la Comunidad Autónoma estudiada, consideran que sus necesidades de formación no son atendidas por la Administración. No obstante, las características complejas del puesto de trabajo que ocupan actualmente estos profesionales y su grado de indefinición, así como las limitaciones de los instrumentos de investigación social utilizados generalmente para la evaluación de necesidades de grandes colectivos dispersos, apuntan a la conveniencia de unas estrategias de evaluación formación basadas en el modelo de reflexión sobre la acción de los profesionales de la orientación en su propia práctica profesional.Training guidance staff personnel actualy attending guidance and counseling services in Spain is an issue demanded by The National Educational Sistem Reform yet started. This important issue is delayed at the present by the most regional education authorities. Need assesment demands a careficlly and sistematic planning and implementation in so far it will be the started point of education and training programs development for counselors. The present paper is an account of a needs training evaluation research on Andalusian (southern Spain) counselors perception about training and continuing education they have received from regional education authorities. The main issues of the research focused on: - Initial in service training counselors received joining the Guidance Services - Special needs and training interests the counselors realice at the present - Interest and oportunity of a joint training venture between Guidance Services and Universities. Research finding pointed out a widespread lack of regional education authorities offers on counselors in service training and the convenience of a reflective practitioner in service training model for counselors linking in the same process both the peed assesment and training delivery system

La transformada de Walsh-Hadamard y otros parámetros en la autenticación biométrica

El patrón de iris es uno de los métodos biométricos más utilizados para la autenticación de individuos. No obstante, uno de sus principales desafíos consiste en lograr una baja tasa de falsos positivos (aceptación de un usuario ilegal) y de forma simultánea una baja tasa de falsos negativos (rechazo de un usuario legal), de modo que la seguridad del sistema sea la mayor posible. En este trabajo se presenta un primer estudio sobre la viabilidad de utilizar como método de verificación de una identidad basada en iris la transformada de Walsh-Hadamard, complementada con la covarianza cruzada y las distancias de Hamming y euclídea. Los primeros resultados muestran que la identificación basada en los cuatro parámetros anteriores presenta excelentes tasas de falsos positivos y negativos. Sin embargo, es preciso llevar a cabo estudios posteriores, que permitan ajustar mejor tales parámetros, para muestras con mayor número de usuarios.Este trabajo ha sido parcialmente subvencionado por el Ministerio de Ciencia e Innovación (España) bajo el proyecto TIN2011-22668

Functional characterization of splicing factor Cwf15 in the maintenance of genomic stability

Motivation: The accumulation of mutations and rearrangements, or the asymmetrical distribution of genetic material during the mitotic process lead to cellular defects known generically as genomic instability. Previously, we isolated a truncated version of cwf15 lacking it last 53 aa (cwf15.d53) which presents two clearly deleterious phenotypes associated with genomic instability: readthrough and aberrant distribution of the cohesin loaded in the chromosomes. These data show that, in addition to its function in splicing, cwf15 plays a fundamental role in the end of transcription and in the charge/discharge cycle of cohesin. The specific objectives of this project are: Expression in trans of the 53 amino acid that lacks the mutant to evaluate self-contained function. Testing in vivo a “proof of concept” design to follow specifically the loaded cohesin in the chromosomes. Finding extragenic suppressors of cwf15 defective function. Methods:  First, we characterized the chromatin segregation defects of cwf15 and compared quantitative-and-quantitatively to other splicing mutant to show that there exist functional differences. Second, we have engineered, and inserted into the genome, different control and experimental expression constructs to assess functional complementation of Cwf15 c-terminal domain in trans. Third, we have designed and constructed a novel system by bi-molecular complementation to monitor cohesin specifically loaded onto the chromosomes in living cells. Fourth, we have generated genetic combinations of cwf15 deletion and truncation with very recently published mutations in transcription termination genes (yth1 and seb1) to show that cwf15 is involved in a RNA processing different from splicing. Results and conclusions: We show that defective cwf15 function phenotype is different from other characterized splicing factors and that a specific gain-of-function mutation in transcription termination seb1 is able to suppress growth defects of cwf15.d53 mutant. Furthermore, a missense mutation in the RNA polII pausing factor yth1 also rescues lethality of cwf15 whole deletion. On the other hand, preliminary experiments suggest that expression in trans of the last 53 amino acids does not reverse the phenotype of cwf15.d53 although it accumulates in the nucleolus

Simulación de la evaporación horaria a partir de datos meteorológicos

[ES] En este artículo se proponen y validan dos modelos, con distinto grado de complejidad, para simular la evaporación a escala horaria en pequeños cuerpos de agua, concretamente en tanques evaporímetros clase A. En primer lugar se ha desarrollado un modelo multicapa, basado en la discretización del volumen de agua en varios estratos. Se han establecido las ecuaciones del balance de energía, tanto en la capa superficial como en las sucesivas capas consideradas, y se ha resuelto el sistema de ecuaciones que configuran el balance energético del tanque mediante aproximaciones iterativas. La validación de este modelo a escala horaria, con datos experimentales obtenidos en Cartagena (España), confirma la existencia de un proceso de mezcla convectivo en el tanque, que produce una homogeneización de la temperatura del agua incluso durante el periodo diurno. Para modelizar correctamente este fenómeno se ha propuesto y validado una función del viento que actúa sobre el coeficiente de mezcla convectivo en el seno del tanque. En una segunda etapa, se ha desarrollado un modelo numérico simplificado que asume un funcionamiento isotermo del tanque. Los resultados obtenidos son similares a los proporcionados por el modelo multicapa, aunque algo menos precisos.Este trabajo ha sido financiado por la Fundación Séneca mediante el proyecto PI-45/00851/FS/01 “Desarrollo y evaluación experimental de un modelo de evaporación de agua en lámina libre. Aplicación a la mejora del aprovechamiento del agua mediante el estudio de la eficiencia de técnicas reductoras de la evaporación en embalses de riego”.Martínez Álvarez, V.; Molina Martínez, J.; González-Real, MM.; Baille, A. (2005). Simulación de la evaporación horaria a partir de datos meteorológicos. Ingeniería del agua. 12(1):39-51. https://doi.org/10.4995/ia.2005.2550OJS3951121Allen R.G., Pereira L.S., Raes D. y Smith M., 1998. Crop evapotranspiration. guidelines for computing crop water requirements. Irrigation and Drainage Paper nº 56, FAO (United Nations), Rome, p. 300.Bloss, G. y Harleman, R.F., 1979. Effect of wind-mixing on the thermocline formation in lakes and reservoirs. Technical Report 249, Ralph M. Parson Laboratory, MIT, Cambridge, MA, p. 68.Brutsaert, W., 1975. On a derivable formula for long-wave radiation from clear skies. Water Resources Research, 11 (5): 742-744.Condie, S.A. y Webster, I.T., 1997. The influence of wind stress, temperature, and humidity gradients on evaporation from reservoirs.Water Resources Research, 33 (12): 2813-2822.Chow, V.T., Maidment, D.R. y Mays, L.W., 1999. Applied Hydrology. Ed. McGraw-Hill, p. 584.Doorembos, J. y Pruitt, W.O., 1977. Crop water requirements. Irrigation and Drainage Paper No. 24, FAO (United Nations), Rome, p. 179.Harleman, D.R.F., 1982. Hidrotermal analisis of lakes and reservoirs. Journal of the Hydrology Division, ASCE, 108: 302-325.Henderson-Sellers, B., 1984. Engineering Limnology. Pitman Advanced Publishing Program, Boston, M.A., p. 356.Jacobs, A.F.G., Heusinkveld, B.G. y Lucassen D.C., 1998. Temperature variation in a class A evaporation pan. Journal of Hydrology, 206: 75 -83.Jacobs, A.F.G., Jetten, Th.H., Lucassen, D.C., Heusinkveld, B.G. y Nieveen, J.P., 1997. Diurnal temperature fluctuations in a natural shallow water body. Agriculture and Forest Meteorology, 88: 269-277.Linsley, R.K.,1958. Techniques for Surveying Water Resources. World Meteorological Organization, Technical Note nº 26, 124 p.Linsley, R.K., Kohler, M.A. y Paulhus, J.L.H., 1992, Evaporation and Transpiration. Hydrology for Engineers. New York, McGrawHill, 508 p.Losordo, T.M. y Piedrahita, R.H., 1991. Modelling temperature variation and termal stratification in shallow aquaculture ponds. Ecological Modelling, 54: 189-226.Miro-Granada, J., 1984. Evaporación en Embalses. Instituto Nacional de Meteorología (INM). Ministerio de Transportes, Turismo y Comunicaciones, Madrid, p.139.Molina, J.M., 2004. Caracterización y modelización de la evaporación en tanques evaporímetros y embalses de riego. Evaluación de los efectos de mallas de sombreo. Tesis Doctoral, Departamento de Ingeniería de Alimentos y del Equipamiento Agrícola, Universidad Politécnica de Cartagena, España, p 207.Molina, J.M., Martínez, V. y Górriz, B., 2003. Automatización con control horario del llenado de tanques evaporímetros clase A. 2º Congreso Nacional de Agroingeniería, Córdoba, España, 451-452.Molina, J.M., Martínez, V. y Baille, A., 2002a. Estación experimental para el registro de las variables implicadas en la modelización del proceso de evaporación y el estudio de diferentes técnicas reductoras. 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Microscopic study of nine galls induced in Populus nigra by aphids of the Iberian Peninsula

[EN] Aphids (Hemiptera, Aphididae) feed on the phloem and some of them induce the formation of conspicuous galls on their primary hosts. Histological studies were proposed to elucidate the evolutionary history of galling habit in Pemphigini tribe, assessing if gall complexity indicates the phylogenetic relations among gall inducers. Nine Eriosomatinae galls induced on Populus nigra from the Iberian Peninsula were studied microscopically. The galls are induced by Pemphigini of the genera Thecabius (2 galls) and Pemphigus (7 galls). Using multiple correspondence analysis of the observed microscopic characteristics, a hierarchical cluster was obtained showing the existence of 2 groups of galls. One group consists of the 2 galls induced by Thecabius and, within the genus Pemphigus, those belonging to the subgenus Pemphigus (P. populi and P. vesicarius). The other group consists of galls of the genus Pemphigus, subgenus Pemphiginus (P. bursarius, P. immunis, P. spyrothecae, P. protospirae and P. populinigrae). The gall histological complexity is related to Pemphigini phylogeny, confirming the importance of such studies in galling aphid taxonomy and possible pathways of galling habit evolution. Similarities are established between the galls of Pemphigini aphids studied here with others we studied microscopically, induced by Fordini and Eriosomatini. Finally, a classification of all Eriosomatinae galls is proposed, establishing 3 groups: galls that cause severe malformations (induced by derived galling taxa), those that cause less severe malformations, and those that cause mild malformations (pseudogalls). It also demonstrates the importance of the strategy of waste evacuation in derived galling speciesS