Optimización de superficies selectivas en frecuencia monocapa mediante BPSO y CG-FFT

A single-layer frequency selective surface (FSS) optimization scheme that combines a Binary Particle Swarm Optimizer (BPSO) with the CG-FFT method, is presented in this work. The BPSO algorithm uses the FSS reflection and transmission coefficients obtained with CG-FFT to carry out the optimization of the FSS geometry, period, and adjacent dielectric materials (thickness and dielectric constant), as required. Optimization constraints are stated in terms of reflection and transmission coefficient masks as a function of frequency. Half-, quarter- and eight-folded symmetry restrictions can be incorporated, if desired, during the optimization process. A summary of results is presented and the pros and cons of the approach are discussed

Coverage optimization and power reduction in SFN using simulated annealing

An approach that predicts the propagation, models the terrestrial receivers and optimizes the performance of single frequency networks (SFN) for digital video broadcasting in terms of the final coverage achieved over any geographical region, enhancing the most populated areas, is proposed in this paper. The effective coverage improvement and thus, the self-interference reduction in the SFN is accomplished by optimizing the internal static delays, sector antenna gain, and both azimuth and elevation orientation for every transmitter within the network using the heuristic simulated annealing (SA) algorithm. Decimation and elevation filtering techniques have been considered and applied to reduce the computational cost of the SA-based approach, including results that demonstrate the improvements achieved. Further representative results for two SFN in different scenarios considering the effect on the final coverage of optimizing any of the transmitter parameters previously outlined or a combination of some of them are reported and discussed in order to show both, the performance of the method and how increasing gradually the complexity of the model for the transmitters leads to more realistic and accurate results.This work was supported by the Spanish Ministry of Science and Innovation under Projects TEC2008-02730 and TEC2012-33321. The work of M. Lanza and Á. L. Gutiérrez was supported by a Pre-Doctoral Grant from the University of Cantabria

Diabesidad y su riesgo cardiovascular global

Introducción: La diabetes mellitus tipo 2 es una enfermedad crónica y sistémica. Se ha visto que tiene una estrecha relación con la obesidad, lo que ha dado lugar al surgimiento del término “diabesidad”. Es un problema creciente el aumento del riesgo cardiovascular en las personas que padecen diabesidad por lo que se hace necesario su prevención.Objetivo: Determinar el riesgo cardiovascular global y su relación con la obesidad en los pacientes diabéticos del área norte de Güines.Diseño Metodológico:Se realizó un estudio observacional descriptivo y transversal para en pacientes diabéticos que asistieron a la consulta de diabetes mellitus de área norte de Güines. Se dividió el universo de estudio en sobrepesos y no sobrepesos, se calculó el riesgo cardiovascular.Resultados: El 77 % de los pacientes investigados fueron valorados como sobrepeso, predominó el riesgo cardiovascular moderado y la posibilidad de desarrollar eventos cardiovasculares fue menos probable en aquellos pacientes que presentaban sobrepeso solo detectado por índice de masa corporal. Las lesiones más frecuentemente encontradas fueron la estenosis de las arterias retinianas (45,3%) y la presencia de placa ateroscleróticas (37,5%).Conclusiones: La diabesidad es un fenómeno frecuente en los diabéticos tipo 2 que participaron en la presente investigación. La probabilidad de desarrollar eventos cardiovasculares en los pacientes sobrepesos diagnosticados por Índice de masa corporal es baja, esta se incrementa si el método utilizado es el cálculo de la circunferencia de la cintura y es aún mayor en aquellos pacientes donde coincide el cálculo del sobrepeso por ambos índices. ABSTRACTIntroduction: The diabetes mellitus type 2 is a chronic and systemic disease. It has been observed that it has a narrow relationship with obesity, what has given place to the emergence of the term "diabesidad." The increase of the cardiovascular risk in people that suffer from diabesity is a growing problem; thus, its prevention is necessary.Objective: To determine the cardiovascular global risk and its relationship with the obesity in diabetic patients of the north of Güines.Methodological design: An observational descriptive and transverse study was carried out. The main focus is on patients that were attended on for diabetes mellitus on the north area of Güines. The sample was divided in overweight and non-overweight; the cardiovascular risk was calculated.Results: The 77% of the investigated patients was valued as overweight. These patients had cardiovascular moderate risk and the possibility of developing cardiovascular events. It was less probable in these patients than in those presenting only overweight detected by index of corporal mass. The most frequently opposing lesions were the stenosis of the retinal arteries (45.3%) and the presence of the atherosclerotic badge (37.5%).Conclusions: The diabesity is a frequent phenomenon in the diabetic type 2 that participated in this investigation. The probability of developing cardiovascular events in the overweight diagnosed patients by index of corporal mass is low; this is increased if the used method is the calculation of the circumference of the waist and, it is even higher in those patients where the calculation of the overweight coincides for both indexes.

Selección de un modelo auto-regresivo optimo utilizando un diccionario de funciones base

El modelamiento de series temporales es una de las tareas más importantes en ingeniería; una vez elegida una clase de modelos, el ingeniero debe determinar unos parámetros que dependen de la clase de modelo elegido y de la señal. Cuando se eligen modelos Autorregresivos, los parámetros a determinar son el orden del modelo y las constantes asociadas. Actualmente existen varios algoritmos para determinar dichos parámetros. En el presente documento se demuestra que algunos de estos algoritmos fallan en situaciones sencillas donde algunas constantes del modelo son iguales a cero, y se presenta una nueva metodología, la cual es robusta ante esta clase de situaciones

Conflictos cognitivos en una muestra comunitaria: un estudio exploratorio

El estudio de los conflictos cognitivos se ha llevado a cabo desde diversas aproximaciones teóricas. En el ámbito de la Psicología de los Constructos Personales, la técnica de la rejilla ha permitido operativizar un tipo de conflicto cognitivo denominado Dilema Implicativo (DI) y estudiar su papel en el campo de la salud. En este trabajo se ha analizado la construcción del sí mismo, la estructura cognitiva y el malestar psicológico en personas con y sin DI pertenecientes a una muestra comunitaria. En la investigación participaron 115 sujetos (56.5% mujeres y 43.5% hombres). Las técnicas de evaluación utilizadas fueron la técnica de la rejilla, y las versiones españolas del Symptom Check List-90-R (SCL-90-R) y el Clinical Outcome in Routine Evaluation (CORE-OM). Los principales resultados revelan correlaciones positivas en las tres medidas del sí mismo, lo que supone una alta autoestima, aunque si se comparan los grupos con/sin DI, se observan correlaciones más bajas en las personas con dilemas. En cuanto a la complejidad cognitiva, las personas con dilemas muestran una estructura cognitiva más diferenciada. Por último, en relación con el malestar psicológico percibido, los dos grupos presentan puntuaciones dentro del rango de la normalidad aunque las personas sin DI se sienten en mayor sintonía consigo mismas/con los demás que las personas con dilemas, presentando estas últimas puntuaciones superiores en escalas de depresión y ansiedad del SCL-90, y en las medidas globales del CORE-O

Leptin receptor expression during the progression of endometrial carcinoma is correlated with estrogen and progesterone receptors

Abstract Introduction: The hormone leptin, which is produced in the adipose tissue, may influence tumorigenesis directly via its receptor (Ob-R). Thus, a role for Ob-R in endometrial carcinogenesis has been proposed. However, most studies neither included samples of the entire histological progression of endometrial carcinoma nor examined Ob-R jointly with the estrogen and progesterone receptors (ER and PR, respectively). Material and methods: To determine the fluctuations of Ob-R, ER, and PR during the histological progression of endometrial carcinoma, we assessed their expression via immunohistochemistry (IHC) in six histological types of endometrium (proliferative, secretory, nonatypical and atypical hyperplasia, and endometrioid and nonendometrioid endometrial carcinoma), in which we performed histopathological and digital scoring for the quantification of receptors. Results: We found that Ob-R expression was positively correlated with that of ER and PR (r = 1, p < 0.001; r = 0.943, p < 0.005, respectively), and there was a significant difference in Ob-R expression among proliferative normal endometrium, hyperplasias, and carcinomas, according to their relative digitally scored Ob-R expression (p < 0.001). In addition, we observed that Ob-R expression in the secretory endometrium was more similar to that of carcinomas than to its proliferative counterpart. Conclusions: These results indicate that Ob-R expression fluctuates during endometrial carcinogenesis in correlation with ER and PR, suggesting that Ob-R expression in vivo is highly dependent on estrogen and progesterone activities in the endometrium and on its ER and PR status, as suggested previously by in vitro studies. Key words: Ob-R, endometrial carcinoma, immunohistochemistr

Re-evaluating the Neolithic: The Impact and the Consolidation of Farming Practices in the Cantabrian Region (Northern Spain)

Abstract:Research projects undertaken in the Cantabrian region since 1980 have produced new, high-quality information about the neolithisation process(es) in this area. It is now necessary to review this archaeological information and test the main hypotheses put forward to explain it. This paper presents an update on the archaeological evidence (sites, chronological dates, archaeozoological, archaeobotanical and technological information) for the early Neolithic in the Cantabrian region. It summarizes recent research on neolithisation in the region, and assesses the impact of this process during the early Neolithic, and its later consolidation. Although the available information is still incomplete, it is now possible to identify the focal point of the introduction of elements characteristic of the Neolithic way of life in the region. Current evidence suggests that it is in the eastern sector, where the earliest arrival of domesticates and new technologies such as pottery has been attested. The existence of continuities?such as sustained reliance on hunting and gathering and the coexistence of old and new funerary rites?suggests the persistence of native populations, which gradually participated in the neolithisation process after an ?availability phase?

Propuesta de esquema de optimización de FSS multicapa

Frequency selective surfaces (FSS) are structures that filter or preserve some frequency bands. Usually, the desired spectral response is obtained tuning manually the dielectric materials and periodic geometries of the FSS. The design process of a FSS is costly and difficult to finish if the filtering response to be synthesized cannot be directly obtained with classical geometries. To overcome this problem, in this paper a heuristic method (PSO) and an analysis methodology of structures with several periodic surfaces (CG-FFT) are combined in order to automate the search. The analysis method uses a multilayer Green’s function that considers the mutual coupling effects using a transmission line model for translating the field from the source FSS to the other periodic surfaces. A comparison with commercial simulators and results for the optimization of a FSS with two periodic layers, are presented to show the usefulness of the approach

Estudio de anillas concéntricas múltiples para su empleo en reflectarrays

In this work, an alternative to traditional phasing elements used in the implementation of reflectarrays is analyzed. This alternative consists of structures with multiple concentric rings and the method used to analyze the phase shift produced by the elements is based on CG-FFT. The performance offered by multiple rings is compared with more traditional structures with monolayer and multilayer patches. The main advantages of multiple concentric rings are their manufacturing ease and their wide range of phase, reaching up to three or four wavelengths. On the contrary, the high sensitivity of the design curves represents their major drawback. In order to assess the effect of the sensitivity to manufacturing tolerances, a manufacturing simulation of a 625-elements reflectarray that compares the degradation introduced in the radiation pattern against the ideal conditions is presented