Sparse inversion of Stokes profiles. I. Two-dimensional Milne-Eddington inversions

Inversion codes are numerical tools used for the inference of physical properties from the observations. Despite their success, the quality of current spectropolarimetric observations and those expected in the near future presents a challenge to current inversion codes. The pixel-by-pixel strategy of inverting spectropolarimetric data that we currently utilize needs to be surpassed and improved. The inverted physical parameters have to take into account the spatial correlation that is present in the data and that contains valuable physical information. We utilize the concept of sparsity or compressibility to develop an new generation of inversion codes for the Stokes parameters. The inversion code uses numerical optimization techniques based on the idea of proximal algorithms to impose sparsity. In so doing, we allow for the first time to exploit the presence of spatial correlation on the maps of physical parameters. Sparsity also regularizes the solution by reducing the number of unknowns. We compare the results of the new inversion code with pixel-by-pixel inversions, demonstrating the increase in robustness of the solution. We also show how the method can easily compensate for the effect of the telescope point spread function, producing solutions with an enhanced contrast.Comment: 13 pages, 8 figures, accepted for publication in A&

Real-time multiframe blind deconvolution of solar images

The quality of images of the Sun obtained from the ground are severely limited by the perturbing effect of the turbulent Earth's atmosphere. The post-facto correction of the images to compensate for the presence of the atmosphere require the combination of high-order adaptive optics techniques, fast measurements to freeze the turbulent atmosphere and very time consuming blind deconvolution algorithms. Under mild seeing conditions, blind deconvolution algorithms can produce images of astonishing quality. They can be very competitive with those obtained from space, with the huge advantage of the flexibility of the instrumentation thanks to the direct access to the telescope. In this contribution we leverage deep learning techniques to significantly accelerate the blind deconvolution process and produce corrected images at a peak rate of ~100 images per second. We present two different architectures that produce excellent image corrections with noise suppression while maintaining the photometric properties of the images. As a consequence, polarimetric signals can be obtained with standard polarimetric modulation without any significant artifact. With the expected improvements in computer hardware and algorithms, we anticipate that on-site real-time correction of solar images will be possible in the near future.Comment: 16 pages, 12 figures, accepted for publication in A&

PENTESTING VOIP PARA DETERMINAR LAS VULNERABILIDADES DEL SERVIDOR DE COMUNICACION DEL AREA DE SOPORTE DE LA EMPRESA CHAPACUETE DE LA CIUDAD DE HUÁNUCO PERIODO 2019

La investigación se enfocó que en análisis de las vulnerabilidades del servidor VOIP de la empresa Chapacuete de la ciudad de Huánuco. El proceso de pentesting consistió en la aplicación de una serie de herramientas bajo software libre para la determinación de vulnerabilidades del servidor de telefonía bajo el sistema operativo GNU/Linux usando la distribución Asterisk. Se realizaron pruebas de ataque usando técnicas como Man In The Middle y ARP spoofing, y se llegaron a descubrir una serie de vulnerabilidades como por ejemplo: puertos abiertos en el servidor, servicios innecesarios habilitados, contraseña del root débil, extensiones con la configuración por defecto, y la vulnerabilidad más importante fue que en el servidor se estaba utilizando como protocolo de comunicación a SIP un protocolo con muchas vulnerabilidad en relación al cifrado de la comunicación. Se pudo advertir a tiempo y corregir las vulnerabilidades, como por ejemplo de utilizar el protocolo IAX para mejorar la seguridad en cuanto al transporte de las comunicaciones por la red de datos. Las pruebas se realizaron en diferentes escenarios, tanto virtual como físico, así mismo se implementó un cronograma de pruebas para llevar a cabo la aplicación de estas herramientas y determinar el proceso o la repetición de las vulnerabilidades en el servidor. En la fase de ataque se simulo un agente en la cual se asumió un cliente conectado a la red para interceptar las llamadas realizadas por los usuarios, con las herramientas especificas se pudo obtener dichas llamadas y guardarlas como archivo para su posterior análisis.Tesi

Airships for Logistics Case Study

Since the beginning of times, humanity has needed transportation of goods, people or animals. As technology advanced and changed, the user's demand was modified. Hence new means of transportation started arising and airships, for instance, have been getting an increasing amount of attention, mostly due to the fact that aeronautical entities have been concerned with adopting environmentally friendly technologies. In this century, airships started to have their fair share of distinct uses: advertisement, surveillance, monitoring, investigation and tourism. In this dissertation another use was analysed, this was logistics freight transportation to inquire if it would be a practical alternative to road transportation and if it could counter some of the nowadays’ restraints found in logistics such as poor street conditions, interdiction to the circulation of some vehicles in certain areas, and traffic congestion. In this thesis, it was shown how using airships for freight and consequently its role in terms of logistics’ distribution is feasible. To do so, the vital elements of a business plan and model were analysed, the network route optimisation methodologies were studied and an approach to a case study based on a real company’s operation in the national market was made. The results confirmed the viability of the initial assumptions corroborating the advantages (along with the challenges) of using airships in the logistics chain of freight transportation.Desde os tempos mais primordiais, o Homem teve a necessidade de transportar bens, pessoas ou animais. Com os avanços e mudanças da tecnologia, também a procura de transporte por parte dos utilizadores sofreu alterações. Neste sentido surgiram novos meios de transporte e os dirigíveis, por exemplo, começaram a ser alvo de um crescente nível de atenção, sobretudo devido ao facto de as entidades aeronáuticas terem uma maior preocupação com a adoção de tecnologias amigas do ambiente. Neste século, os dirigíveis começaram a ter a sua quota-parte nos mais diversos usos: publicidade, vigilância, monitorização, investigação e turismo. Nesta dissertação foi analisado um outro uso, o transporte de carga, para perceber se este poderia ser uma alternativa prática relativamente ao transporte rodoviário e se assim se poderia contrariar algumas das restrições encontradas no que toca à logística tais como: vias rodoviárias em mau estado de conservação, interdições à circulação de alguns tipos de veículos em certas áreas, e congestionamento de tráfego. Neste trabalho mostrou-se como a utilização de dirigíveis para o transporte de carga e, consequentemente, o seu papel em termos da logística de distribuição, é exequível. Para tal, foram analisados os elementos essenciais a um modelo e plano de negócios, estudadas as metodologias de otimização em rede de possíveis rotas, e abordado um caso de estudo com base na operação real de uma empresa no mercado nacional. Os resultados confirmaram a viabilidade dos pressupostos iniciais corroborando as vantagens (mas também os desafios) da utilização de dirigíveis na cadeia logística do transporte de carga

Interactive Model of Executive Functions to Understand Error Correction

This article reports an investigation aimed at analyzing an interactive model of executive functions, which seeks to explain the process followed by human beings to correct their mistakes. The method followed was an analysis based on structural equations, considering the maximum likelihood process around a model that considered six executive functions. We worked with a randomized sample of 771 subjects (mean age = 39.86, SD = 15.47; 50.5%, women, 50.50%). The findings suggest that error correction is a complex executive function as it is the product of the internal language capacity that regulates behavior and cognition, adequate regulation of the limbic system, adequate decision-making, and control of automatic impulses, determining how to act and verify the thoughts and behavior of the subject. The contribution of the proposed theoretical model lies in understanding the process by which human beings manage to correct errors. In addition, how this explanatory model could help neuropsychological intervention processes to work on this cognitive ability in individuals with difficulties in correcting errors. Doi: 10.28991/ESJ-2022-06-02-011 Full Text: PD

Observations of Ellerman bomb emission features in He I D3 and He I 10830 {\AA}

Context. Ellerman bombs (EBs) are short-lived emission features, characterized by extended wing emission in hydrogen Balmer lines. Until now, no distinct signature of EBs has been found in the He I 10830 {\AA} line, and conclusive observations of EBs in He I D 3 have never been reported. Aims. We aim to study the signature of EBs in neutral helium triplet lines. Methods. The observations consist of 10 consecutive SST/TRIPPEL raster scans close to the limb, featuring the H$\beta$, He I D3 and He I 10830 {\AA} spectral regions. We also obtained raster scans with IRIS and make use of the SDO/AIA 1700 {\AA} channel. We use Hazel to invert the neutral helium triplet lines. Results. Three EBs in our data show distinct emission signatures in neutral helium triplet lines, most prominently visible in the He I D3 line. The helium lines have two components: a broad and blue-shifted emission component associated with the EB, and a narrower absorption component formed in the overlying chromosphere. One of the EBs in our data shows evidence of strong velocity gradients in its emission component. The emission component of the other two EBs could be fitted using a constant slab. Our analysis hints towards thermal Doppler motions having a large contribution to the broadening for helium and IRIS lines. We conclude that the EBs must have high temperatures to exhibit emission signals in neutral helium triplet lines. An order of magnitude estimate places our observed EBs in the range of $T\sim 2\cdot 10^4-10^5$ K.Comment: 15 pages, 14 figure