Dark matter and galaxy rotation curves

Cosmological N-body simulations on structure formation in a \u39b 12CDM scenario point to a mass density distribution of dark matter, in local objects like galaxies, that are in strong tension with recent observations on low surface brightness galaxies. Modified theories of gravity lack of this problem but also find tensions with observations at larger scales. In this thesis we study the main methods for galaxy rotation curve fitting, from modified theories of gravity such as MOND and f (R) = R n , and considering dark matter halos, such as the one derived from the \u39b 12CDM numerical simulations and the phenomenological Burkert cored halo profile. To investigate the properties of the dark matter halo that surrounds galaxies, two methods are examined: the standard mass modeling and the local density method. All these methods are applied to the study of the rotation curve of the galaxy M33, which is well extended and measured with an unprecedent high spatial resolution. Later on, we present a unified parameterization of the circular velocity which accurately fits 887 galactic rotation curves without needing in advance the knowledge of the luminous matter components, nor a fixed dark matter halo model. A notable feature of this parametrization is that the associated gravitational potential increases with the distance from the galactic center, giving rise to a length scale indicating a finite size of a galaxy, and after, the keplerian fall-off of the velocity is recovered, making possible for the prediction of the total mass enclosed by the galaxy. As the keplerian regime is reached after a finite length scale, based on isotropy and homogeneity arguments, we considered a static and spherically symmetric Schwarzschild-like space time embedding each galaxy, such that any massive particle moving in geodesic circumferences in the equatorial plane, turns around origin of coordinates with the newly found parameterized velocity formula. Appealing to the General Relativity field equations, for a perfect fluid with pressure anisotropies, we found that the dark matter halo behaves like a cosmological constant in the outer parts of galaxies and controls the distribution shape of the luminous matter component by means of the anisotropic pressure in the azimuthal direction

THz Ultra-wideband Passive Devices: Design, Simulation and Characterization

The last decades have seen an increasing interest in the THz research field, leading to a substantial improvement in technology and the emergence of new applications. In particular, the research on radio astronomy instrumentation has pushed millimeter and sub-millimeter technology boundaries and redefined state of the art.\ua0 Nonetheless, the requirements set for the next generation of radio astronomy receivers will demand remarkable technological development, especially in terms of RF and IF bandwidth. Addressing this need, the present licentiate thesis focuses on the design, simulation and characterization of ultra-wideband THz passive devices for the next generation of radio astronomy receivers. As THz receivers mixers are implemented with thin-film technology, waveguide to substrate transitions have a fundamental role in the performance and bandwidth of such systems. The critical requirements for these transitions are a proper impedance matching and the minimization of insertion loss. In this thesis, a waveguide to slotline superconducting transition based on substrateless finlines is proposed. The transition was designed for prospective broadband SIS mixer design in the frequency range 211-375 GHz. The experimental verification at cryogenic temperatures shows a remarkable fractional bandwidth of 55%. Although this transition represents a substantial improvement over existing designs, it is important to note that it transforms a waveguide propagation mode into slotline mode. For the majority of modern SIS mixers, microstrip line topology is the most suitable. Hence, the ongoing development is focused on broadband slotline to microstrip transitions. In this work, a slotline to microstrip transition based on Marchand Balun is designed, simulated and fabricated. The electromagnetic simulations showed promising results, and the cryogenic characterization at 4K is ongoing.For most modern polarization-sensitive THz receivers, 90\ub0 waveguide twists are essential interconnection parts. Since compactness and low insertion loss are critical requirements, single step-twists have emerged as an attractive solution. In this work, a novel compact wideband 90-degree twist for the 140-220 GHz band is presented. Furthermore, the proposed twist has a performance tolerant to small geometry variation, and hence it is especially suited for fabrication by direct milling. The experimental verification shows 44% fractional bandwidth with return loss better than 20 dB over most of the band

Practical Heterogeneous Unification for Dependent Type Checking

Dependent types can specify in detail which inputs to a program are allowed, and how the properties of its output depend on the inputs. A program called the type checker assesses whether a program has a given type, thus detecting situations where the implementation of a program potentially differs from its intended behaviour. When using dependent types, the inputs to a program often occur in the types of other inputs or in the type of the output. The user may omit some of these redundant inputs when calling the program, expecting the type-checker to infer those subterms automatically. Some type-checkers restrict the inference of missing subterms to those cases where there is a provably unique solution. This makes the process more predictable, but also limits the situations in which the omitted terms can be inferred; specially when considering that whether a unique solution exists is in general an undecidable problem. This restriction can be made less limiting by giving flexibility to the type-checker regarding the order in which the missing subterms are inferred. The type-checker can then use the information gained by filling in any one subterm in order to infer others, until the whole program has been type-checked. However, this flexibility may in some cases lead to ill-typed subterms being inferred, breaking internal invariants of the type-checker and causing it to crash or loop. The type checker could mitigate this by consistently rechecking the type of each inferred subterm, but this might incur a performance penalty.\ua0An approach by Gundry and McBride (2012) called twin types has the potential to afford the desired flexibility while preserving well-typedness invariants. However, this method had not yet been tested in a practical setting. In this thesis we streamline the method of twin types in order to ease its practical implementation, justify the correctness of our modifications, and then implement the result in an established dependently-typed language called Agda. We show that our implementation resolves certain existing bugs in Agda while still allowing a wide range of examples to be type-checked, and achieves this without heavily impacting performance

Practical Unification for Dependent Type Checking

When using popular dependently-typed languages such as Agda, Idris or Coq to write a proof or a program, some function arguments can be omitted, both to decrease code size and to improve readability.\ua0 Type checking such a program involves inferring a combination of these implicit arguments that makes the program type-correct.Finding such a combination of implicit arguments entails solving a higher-order unification problem.Because higher-order unification is undecidable, our aim is to infer the omitted arguments for as many programs as possible with a reasonable use of computational resources. The extent to whichthese goals are achieved affect how usable a dependently-typed proof assistant or programming language is in practice.Current approaches to higher-order unification are in some cases too inflexible, postponing unification of terms until their types have been unified (Coq, Idris). In other cases they are too optimistic, which sometimes leads to ill-typed terms that break internal invariants (Agda).In order to increase the flexibility of our unifier without sacrificing soundness, we use the twin types technique by Gundry and McBride. We simplify their approach so that it can be used within an existing typetheory without changes to the syntax of terms. We also extend it so that it can handle more classes of constraints. We show that the resulting solutions are correct and unique.Finally, we implement the resulting unification algorithm on an existing type checker prototype for a smaller variant of the Agda language, developed by Mazzoli and Abel. We make a suitable choice of internal term representation, and use few, if any, example-specific optimizations. We obtain a type-checker which avoids ill-typed solutions, and is also able to handle some challenging examples in time and memory comparable to the existing Agda implementation

ESCENARIO LABORAL DEL DECANATO DE CIENCIAS ECON 3MICAS Y EMPRESARIALES DE LA UCLA DESDE LA PERSPECTIVA DE LA CAPACITACI 3N DEL PERSONAL DE APOYO.

En el presente art\uedculo se analiza el escenario laboral del personal de apoyo del Decanato de Ciencias Econ\uf3micas y Empresariales de la Universidad Centroccidental "Lisandro Alvarado", con la finalidad de conocer el proceso de capacitaci\uf3n. Se desarroll\uf3 en dos fases, un diagn\uf3stico con la opini\uf3n de tres grupos inherentes a la capacitaci\uf3n y otra de contraste a igualdad de t\ue9rminos, generando una matriz que permiti\uf3 describir el escenario laboral del decanato. La poblaci\uf3n estuvo conformada por 36 sujetos, a quienes se les aplic\uf3 un instrumento previamente validado y su confiabilidad se determin\uf3 por medio del m\ue9todo de Alfa de Cr\uf6nbach. Los resultados evidenciaron que los cursos de formaci\uf3n recibidos por el personal administrativo de apoyo no son suficientes, que no existe un instrumento para conocer sus necesidades de capacitaci\uf3n, carencia de periodicidad para aplicar la capacitaci\uf3n al personal, ni responsabilidad de realizar medici\uf3n de desempe\uf1o en los diferentes cargos, que el trabajador no recibe una adecuada capacitaci\uf3n profesional en atenci\uf3n a los objetivos del \ue1rea donde se va a desenvolver. Se concluye que existe una necesidad apremiante de instrumentar innovaciones de capacitaci\uf3n que partan de la relaci\uf3n entre las necesidades de cada Decanato. Palabras Clave: Capital humano, capacitaci\uf3n, competencias, escenario laboral. ABSTRACT This article analyzes the labor scenario of the support staff of the Faculty of Economics and Business Sciences of the "Lisandro Alvarado" Centroccidental University, in order to know the training process. It was developed in two phases, a diagnosis with the opinion of three groups inherent to the training and another one in equal terms as a contrast, generating a matrix that allowed to describe the work scenario in the Faculty. Population included 36 subjects, who were given a previously validated instrument and their reliability was determined using the Cr\uf6nbach Alpha method. The results showed that the training courses received by support staff are not sufficient, there is no instrument to know their training needs, there is no training periodicity, nor measurement responsibility of performance in positions, and employees do not receive an adequate professional training in attention to the objectives of the area where it is going to develop. It is concluded that there is an urgent need to implement training innovations based on the needs of each Faculty. Keywords: Human capital, training, skills, labor scenario. RESUMO Neste artigo \ue9 analisado o cen\ue1rio de trabalho do pessoal de apoio da faculdade de ci\ueancias econ\uf4micas e empresariais da Universidade Centroccidental "Lisandro Alvarado" (UCLA), com o fim de conhecer o processo de forma\ue7\ue3o. O trabalho foi desenvolvido em duas fases, uma de diagn\uf3stico com a opini\ue3o de tr\ueas grupos inerente \ue0 forma\ue7\ue3o e outra de contraste com igualdade de condi\ue7\uf5es, gerando uma matriz que permitiu descrever o cen\ue1rio de trabalho da faculdade. A popula\ue7\ue3o esteve conformada de 36 indiv\uedduos aos quais se aplicou um instrumento previamente validado e sua confiabilidade foi determinada pelo m\ue9todo de alfa de Cronbach. Os resultados mostraram que a forma\ue7\ue3o recebida pelo pessoal de apoio administrativo n\ue3o s\ue3o suficientes, que n\ue3o h\ue1 nenhuma ferramenta para determinar as suas necessidades de forma\ue7\ue3o, falta de periodicidade para a implementa\ue7\ue3o da forma\ue7\ue3o do pessoal n\ue3o h\ue1 responsabilidade de realizar a medi\ue7\ue3o do desempenho nas diferentes fun\ue7\uf5es dos trabalhadores e n\ue3o recebem forma\ue7\ue3o profissional adequada aos objetivos da \ue1rea onde eles v\ue3o se desenvolver. Concluiu-se que h\ue1 uma necessidade premente para implementar inova\ue7\uf5es de forma\ue7\ue3o que se originem da rela\ue7\ue3o entre as necessidades de cada faculdade. Palavras-chave: Capital humano, habilidades, treinamento. <br

Multi-Trait, Multi-Environment Genomic Prediction of Durum Wheat With Genomic Best Linear Unbiased Predictor and Deep Learning Methods

Although durum wheat (Triticum turgidum var. durum Desf.) is a minor cereal crop representing just 5\u20137% of the world\u2019s total wheat crop, it is a staple food in Mediterranean countries, where it is used to produce pasta, couscous, bulgur and bread. In this paper, we cover multi-trait prediction of grain yield (GY), days to heading (DH) and plant height (PH) of 270 durum wheat lines that were evaluated in 43 environments (country\u2013location\u2013year combinations) across a broad range of water regimes in the Mediterranean Basin and other locations. Multi-trait prediction analyses were performed by implementing a multi-trait deep learning model (MTDL) with a feed-forward network topology and a rectified linear unit activation function with a grid search approach for the selection of hyper-parameters. The results of the multi-trait deep learning method were also compared with univariate predictions of the genomic best linear unbiased predictor (GBLUP) method and the univariate counterpart of the multi-trait deep learning method (UDL). All models were implemented with and without the genotype 7 environment interaction term. We found that the best predictions were observed without the genotype 7 environment interaction term in the UDL and MTDL methods. However, under the GBLUP method, the best predictions were observed when the genotype 7 environment interaction term was taken into account. We also found that in general the best predictions were observed under the GBLUP model; however, the predictions of the MTDL were very similar to those of the GBLUP model. This result provides more evidence that the GBLUP model is a powerful approach for genomic prediction, but also that the deep learning method is a practical approach for predicting univariate and multivariate traits in the context of genomic selection

SIMULACI 3N NUM\uc9RICA DEL COMPORTAMIENTO ESTRUCTURAL DE PERFILES TUBULARES SOMETIDOS A FATIGA DE ULTRA-BAJO CICLAJE

En el presente trabajo de investigaci\uf3n se estudia el comportamiento num\ue9rico de perfiles estructurales de acero de pared delgada, de producci\uf3n nacional venezolana Conduven ECO, de secci\uf3n transversal cuadrada, construidos en forma de viga tipo cantil\ue9ver, bajo los efectos de Fatiga de Ultra-Bajo Ciclaje. Se realizaron ensayos experimentales donde se aplicaron historias de desplazamientos c\uedclicos, con muy baja velocidad y actuando en un rango que va desde el esfuerzo cedente hasta el esfuerzo \ufaltimo del elemento, obteniendo una degradaci\uf3n de la capacidad resistente de los perfiles, estos resultados experimentales fueron comparados con las simulaciones num\ue9ricas realizadas mediante un programa comercial de elementos finitos, obteniendo resultados satisfactorios. Palabras clave: fatiga de ultra-bajo ciclaje; elementos tubulares de acero; falla por pandeo local ABSTRACT In the present work of investigation the numerical behavior of structural profiles of steel of thin wall is studied, of Venezuelan national production Conduven ECO, of square cross section, constructed in the form of beam type cantilever, under the effects of Fatigue of Ultra-Low Cycling. Experimental tests were carried out where histories of cyclic displacements were applied, with very low speed and acting in a range that goes from the yielding effort to the last effort of the element, obtaining a degradation of the resistant capacity of the profiles, these experimental results were compared with the numerical simulations made through a commercial program of finite elements, obtaining satisfactory results. Keywords: ultra-low cycling fatigue; tubular steel elements; fails due to local buckling <br

Practical dependent type checking using twin types

People writing proofs or programs in dependently typed languages can omit some function arguments in order to decrease the code size and improve readability. Type checking such a program involves filling in each of these implicit arguments in a type-correct way. This is typically done using some form of unification.One approach to unification, taken by Agda, involves sometimes starting to unify terms before their types are known to be equal: in some cases one can make progress on unifying the terms, and then use information gleaned in this way to unify the types. This flexibility allows Agda to solve implicit arguments that are not found by several other systems. However, Agda\u27s implementation is buggy: sometimes the solutions chosen are ill-typed, which can cause the type checker to crash.With Gundry and McBride\u27s twin variable technique one can also start to unify terms before their types are known to be equal, and furthermore this technique is accompanied by correctness proofs. However, so far this technique has not been tested in practice as part of a full type checker.We have reformulated Gundry and McBride\u27s technique without twin variables, using only twin types, with the aim of making the technique easier to implement in existing type checkers (in particular Agda). We have also introduced a type-agnostic syntactic equality rule that seems to be useful in practice. The reformulated technique has been tested in a type checker for a tiny variant of Agda. This type checker handles at least one example that Coq, Idris, Lean and Matita cannot handle, and does so in time and space comparable to that used by Agda. This suggests that the reformulated technique is usable in practice

The calibration of the first Large-Sized Telescope of the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) represents the next generation of very high-energy gamma-ray observatory, which will provide broad coverage of gamma rays from 20 GeV to 300 TeV with unprecedented sensitivity. CTA will employ three different sizes of telescopes, and the Large-Sized Telescopes (LSTs) of 23-m diameter dish will provide the sensitivity in the lowest energies down to 20 GeV. The first LST prototype has been inaugurated in October 2018 at La Palma (Canary Islands, Spain) and has entered the commissioning phase. The camera of the LST consists of 265 PMT modules. Each module is equipped with seven high-quantum-efficiency Photomultiplier Tubes (PMTs), a slow control board, and a readout board. Ensuring high uniformity and precise characterization of the camera is the key aspects leading to the best performance and low systematic uncertainty of the LST cameras. Therefore, prior to the installation on site, we performed a quality check of all PMT modules. Moreover, the absolute calibration of light throughput is essential to reconstruct the amount of light received by the telescope. The amount of light is affected by the atmosphere, by the telescope optical system and camera, and can be calibrated using the ring-shaped images produced by cosmic-ray muons. In this contribution, we will show the results of off-site quality control of PMT modules and on-site calibration using muon rings. We will also highlight the status of the development of Silicon Photomultiplier modules that could be considered as a replacement of PMT modules for further improvement of the camera

Children with Hearing Disabilities during the Pandemic: Challenges and Perspectives of Inclusion

The COVID-19 has dramatically increased the inequalities of the opportunities to education and health services of the children with disabilities. The data collected from international agencies between 2020 and 2021 demonstrate the danger of further rising the risk of exclusion of children with disabilities especially in developing countries. The marginalization of people with sensory disabilities during the Pandemic have further expanded compared to the pre- COVID situation. The article aims to investigate the barriers that children with hearing disabilities have encountered in accessing socio-educational and rehabilitation services and reflect on the importance of social support flexibly from different local actors. In this perspective, the Center of Attention for Communication, Hearing and Language of the Central American University Jos\ue9 Sime\uf3n Ca\uf1as of El Salvador provides educational and rehabilitation service aimed to children with hearing disabilities transforming their methodologies and practices. Based on this analysis, perspectives of action and research will be envisaged to plan the future starting from the lessons learned