Estimating demand elasticities of fixed telephony in Brazil

This paper provides estimates of the elasticities of demand for the Brazilian basic plan of local fixed telephony using a cointegration model. We find a long-run price elasticity of –0.24, and an income elasticity of 0.18. These figures are line with other countries' estimates.

CP Violation and Flavour Mixings in Orbifold GUTs

We address the flavour problem by incorporating the hypothesis of universal strength of Yukawa couplings in the framework of a 5D GUT model compactified on an $S^1/(Z_2 \times Z_2^{\prime})$ orbifold. We show that a quantitatively successful picture of fermion masses and mixings emerges from the interplay between the bulk suppression factors of geometric origin and the phases of the Yukawa matrices. We give an explicit example, where we obtain a good fit for both the CKM and PMNS matrices.Comment: 8 pages, no figures; v2: minor changes, published in Phys Rev D (Rapid Communication

Comportamiento de los déficit financieros: Causa de una ineficiente administración pública estatal y municipal

La Administración Pública se ha materializado como uno de los principales entes de estudio en las áreas de Gobierno por cumplir múltiples funciones en favor a la sociedad, sus recursos, sus políticas y su conformación de la misma, pero a lo largo del tiempo, de los cambios políticos y de las nuevas implantaciones económicas e inclusive mercantiles se ha visto considerablemente afectada. Así, variables como el aumento de la población, la amplia gama de partidos políticos con tendencias o ideologías muy distintas unos de otros, duración o estancia de los gobiernos en el poder, ámbitos políticos y manipulación de estancias u organismos exteriores a los de nuestro país (internacionales) han sido la principal causa del decline político-administrativo, empero destaquemos que principalmente se ha visto reflejado en el aspecto económico. En las entidades federativas y municipios que conforman a México se han arrojado un sinfín de obstáculos y limitantes que evita tener un equilibrio o estabilidad financiera en favor al progreso comunitario y económico del país

Development of security mechanisms for a multi-agent cyber-physical conveyor system using machine learning

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáOne main foundation of the Industry 4.0 is the connectivity of devices and systems using Internet of Things technologies, where Cyber-physical systems (CPS) act as the backbone infrastructure based on distributed and decentralized structures. CPS requires the use of Artificial Intelligence (AI) techniques, such as Multi-Agent Systems (MAS), allowing the incorporation of intelligence into the CPS through autonomous, proactive and cooperative entities. The adoption of this new generation of systems in the industrial environment opens new doors for various attacks that can cause serious damage to industrial production systems. This work presents the development of security mechanisms for systems based on MAS, where these mechanisms are used in an experimental case study that consists of a multiagent cyber-physical conveyor system. For this purpose, simple security mechanisms were employed in the system, such as user authentication, signature and message encryption, as well as other more complex mechanisms, such as machine learning techniques that allows the agents to be more intelligent in relation to the exchange of messages protecting the system against attacks, through the classification of the messages as reliable or not, and also an intrusion detection system was carried out. Based on the obtained results, the efficient protection of the system was reached, mitigating the main attack vectors present in the system architecture.Uma das principais bases da Indústria 4.0 é a conectividade de dispositivos e sistemas utilizando as tecnologias da Internet das Coisas, onde os sistemas ciber-físicos atuam como a infraestrutura principal com base em estruturas distribuídas e descentralizadas. Os sistemas ciber-físicos requerem o uso de técnicas de Inteligência Artificial, como por exemplo, Sistemas Multi-Agentes, permitindo a incorporação de inteligência nos sistemas ciber-físicos através de entidades autônomas, proativas e cooperativas. A adoção dessa nova geração de sistemas no ambiente industrial abre novas portas para vários ataques que podem causar sérios danos aos sistemas de produção industrial. Este trabalho apresenta o desenvolvimento de mecanismos de segurança para sistemas baseados em sistemas multi-agentes, em que esses mecanismos são utilizados em um caso de estudo experimental que consiste em um sistema de transporte ciber-físico baseado em sistemas multi-agentes. Para isso, mecanismos simples de segurança foram empregados no sistema, como autenticação do usuário, assinatura e criptografia de mensagens, além de outros mecanismos mais complexos, como técnicas de aprendizagem de máquina, que permite que os agentes sejam mais inteligentes em relação à troca de mensagens, protegendo o sistema contra ataques, através da classificação das mensagens como confiáveis ou não, e também foi realizado um sistema de detecção de intrusões. Com base nos resultados obtidos, obteve-se uma proteção eficiente do sistema, mitigando os principais vetores de ataque presentes na arquitetura do sistema

Estudio en la síntesis, derivatización superficial, procesado y análisis tecno-económico de un compuesto de PLA - Nanocelulosa

Treballs Finals de Grau d'Enginyeria de Materials, Facultat de Química, Universitat de Barcelona, Any: 2020, Tutor: Javier Fernández GonzálezAs a biodegradable material that can be obtained from sustainable resources, Polylactic acid (PLA) has positioned itself among one of the most prominent materials to substitute petrochemical-based plastics in our quest towards a circular, carbon-neutral economy. On the other hand, Cellulose, a natural polymer found as a reinforcement element in plants, cells and tissue, has a proven record of use not only as paper, but also in many composite applications as a thickening agent, as a binder, or as reinforcement in composite materials. Despite its great prospects, PLA has some serious drawbacks in its mass adoption as a substitute material of mainstream olefins, mainly due to its relatively poor mechanical, thermal and permeability properties. As such, Cellulose, in particular that which is sourced from agricultural waste products, such as Soy Husks, and scaled to its nano-constituent particles, has the potential to be used as a reinforcement and filler material in PLA, improving its weak properties. However, due to their different surface behavior, a mixture of PLA and Nanocellulose is hard to achieve without special processes. The goal of this final degree project is to study the processes in place to individualize the different nano-constituents of Cellulose, namely Cellulose Nanofibers (CNF), modify its surface behavior to make it compatible to PLA and explore the processes to which a PLA – Nanocellulose composite could be produced. This study has been made based on existing bibliography from other research fellows and the most prominent pathway to a PLA – Nanocellulose composite has been presented on this study along with a techno-economic analysis of its viabilit