Scaling Laws for Infrastructure Single and Multihop Wireless Networks in Wideband Regimes

With millimeter wave bands emerging as a strong candidate for 5G cellular networks, next-generation systems may be in a unique position where spectrum is plentiful. To assess the potential value of this spectrum, this paper derives scaling laws on the per mobile downlink feasible rate with large bandwidth and number of nodes, for both Infrastructure Single Hop (ISH) and Infrastructure Multi-Hop (IMH) architectures. It is shown that, for both cases, there exist \emph{critical bandwidth scalings} above which increasing the bandwidth no longer increases the feasible rate per node. These critical thresholds coincide exactly with the bandwidths where, for each architecture, the network transitions from being degrees-of-freedom-limited to power-limited. For ISH, this critical bandwidth threshold is lower than IMH when the number of users per base station grows with network size. This result suggests that multi-hop transmissions may be necessary to fully exploit large bandwidth degrees of freedom in deployments with growing number of users per cell.Comment: 5 pages, 3 figure

Self-adaptation of Genetic Operators Through Genetic Programming Techniques

Here we propose an evolutionary algorithm that self modifies its operators at the same time that candidate solutions are evolved. This tackles convergence and lack of diversity issues, leading to better solutions. Operators are represented as trees and are evolved using genetic programming (GP) techniques. The proposed approach is tested with real benchmark functions and an analysis of operator evolution is provided.Comment: Presented in GECCO 201

Unified Capacity Limit of Non-coherent Wideband Fading Channels

In non-coherent wideband fading channels where energy rather than spectrum is the limiting resource, peaky and non-peaky signaling schemes have long been considered species apart, as the first approaches asymptotically the capacity of a wideband AWGN channel with the same average SNR, whereas the second reaches a peak rate at some finite critical bandwidth and then falls to zero as bandwidth grows to infinity. In this paper it is shown that this distinction is in fact an artifact of the limited attention paid in the past to the product between the bandwidth and the fraction of time it is in use. This fundamental quantity, called bandwidth occupancy, measures average bandwidth usage over time. For all signaling schemes with the same bandwidth occupancy, achievable rates approach to the wideband AWGN capacity within the same gap as the bandwidth occupancy approaches its critical value, and decrease to zero as the occupancy goes to infinity. This unified analysis produces quantitative closed-form expressions for the ideal bandwidth occupancy, recovers the existing capacity results for (non-)peaky signaling schemes, and unveils a trade-off between the accuracy of approximating capacity with a generalized Taylor polynomial and the accuracy with which the optimal bandwidth occupancy can be bounded.Comment: Accepted for publication in IEEE Transactions on Wireless Communications. Copyright may be transferred without notic

Dynamic Time-domain Duplexing for Self-backhauled Millimeter Wave Cellular Networks

Millimeter wave (mmW) bands between 30 and 300 GHz have attracted considerable attention for next-generation cellular networks due to vast quantities of available spectrum and the possibility of very high-dimensional antenna ar-rays. However, a key issue in these systems is range: mmW signals are extremely vulnerable to shadowing and poor high-frequency propagation. Multi-hop relaying is therefore a natural technology for such systems to improve cell range and cell edge rates without the addition of wired access points. This paper studies the problem of scheduling for a simple infrastructure cellular relay system where communication between wired base stations and User Equipment follow a hierarchical tree structure through fixed relay nodes. Such a systems builds naturally on existing cellular mmW backhaul by adding mmW in the access links. A key feature of the proposed system is that TDD duplexing selections can be made on a link-by-link basis due to directional isolation from other links. We devise an efficient, greedy algorithm for centralized scheduling that maximizes network utility by jointly optimizing the duplexing schedule and resources allocation for dense, relay-enhanced OFDMA/TDD mmW networks. The proposed algorithm can dynamically adapt to loading, channel conditions and traffic demands. Significant throughput gains and improved resource utilization offered by our algorithm over the static, globally-synchronized TDD patterns are demonstrated through simulations based on empirically-derived channel models at 28 GHz.Comment: IEEE Workshop on Next Generation Backhaul/Fronthaul Networks - BackNets 201

Caracterización Antropometríca De Peleadores De Muaythai En Cali Colombia

Introduction: The objective of this study was to determine the anthropometric measures of Muay Thai competitors in Cali, Colombia, to have a comprehensive analysis of the variables of this nature that may be affecting the sport's performance. Methods: An observational, quantitative, non-experimental, cross-sectional design was carried out, where the anthropometric measures of 16 Muay Thai competitors were evaluated, belonging to 4 mixed martial arts academies located in the city of Cali, Colombia. The 43 anthropometric measures accepted in the complete ISAK profile were taken by an ISAK certified level 2 anthropometrist. Results: The results showed that the athletes had an average adipose mass of 23% with an IMO of 4.0 and a predominantly mesomorphic somatotype. In addition, significant differences were found between the academies where the athletes came from, in terms of their body weight and body fat percentage. Conclusion: This study allowed for the identification of anthropometric measures of Muay Thai athletes in Cali, which can be of great help to coaches and athletes in planning their training and in making decisions regarding weight loss strategies before competitions. Additionally, the results suggest that membership in different academies may have an impact on the anthropometric characteristics of athletes, which may be important in the selection and recruitment of new talent.Introducción: El objetivo de este estudio fue determinar las medidas antropométricas de deportistas competidores de muaythai en la ciudad de Cali en Colombia, con el fin de tener un análisis completo de las variables de esta naturaleza que puedan estar afectando el rendimiento del deporte. Métodos: Se llevó a cabo un diseño observacional de carácter cuantitativo no experimental y de corte transversal, donde se evaluaron las medidas antropométricas de 16 deportistas competidores de muaythai, pertenecientes a 4 academias de artes marciales mixtas ubicadas en la ciudad de Cali, Colombia. Se tomaron las 43 medidas antropométricas aceptadas en el perfil completo del ISAK, las cuales fueron tomadas por un antropometrista nivel 2 certificado por el ISAK. Resultados: Los resultados mostraron que los deportistas presentaron una media de masa adiposa de 23% con IMO de 4,0 y un somatotipo predominantemente mesomórfico. Además, se encontraron diferencias significativas entre las academias de donde provenían los deportistas, en cuanto a su peso corporal y porcentaje de grasa corporal. Conclusión: Este estudio permitió identificar las medidas antropométricas de los deportistas de muaythai en la ciudad de Cali, lo cual puede ser de gran ayuda para entrenadores y deportistas en la planificación de su entrenamiento y en la toma de decisiones en cuanto a las estrategias de pérdida de peso antes de las competencias. Además, los resultados sugieren que la pertenencia a diferentes academias puede tener un impacto en las características antropométricas de los deportistas, lo cual puede ser importante en la selección y reclutamiento de nuevos talentos

Perfil Logístico de Colombia – Sector textil y confecciones

El sector textil en los últimos 10 años se ha caracterizado por pertenecer a uno de los rubros superiores frente a la economía nacional por lo cual actualmente se está enfrentando a economías emergentes como la china y a mercados como el americano con costos muchos más competentes. Este proyecto, describirá de manera específica el perfil logístico del sector textil en Colombia, el cual debido al auge que ha tenido en los últimos años es importante destacar la relevancia de la logística para llevar a cabo sus objetivos y también al ser uno de los sectores manufactureros de mayor importancia para el desarrollo económico nacional, representando una industria altamente integrada y presentar un flujo de constante de productos; se pretende identificar las oportunidades de mejora en la logística, para lograr mayor eficiencia y efectividad en el sistema de transporte de mercancías del sector. A su vez, este proyecto representará una caracterización enfocada en los países más representativos del sector en términos de exportaciones, importaciones, balanza comercial, productividad y competitividad cuya variable principal es el PIB de cada país. La investigación se complementará con un enfoque desde el punto de vista nacional teniendo en cuenta la cadena de suministro del sector.In the last 10 years the textile sector has been characterized to belong to one of the main industries in the national economy, therefore nowadays is facing strong economies like China and markets as the American with relatively more competitive costs. This project will describe in a specific way the logistic profile of the textile sector in Colombia, which has had a significant growth in the last years, it is important to highlight the roll of the logistic to accomplish their goals and also to be one of the most important manufacturing sectors to the national economic development, representing an industry highly integrated and with a continuous flow of products; it is aim to identify the opportunities to be able to improve the logistic, to get more efficiency and effectiveness in the transport system of merchandising. At the same time, this project will represent a characterization focused in the countries more representative of the sector based on GDP in terms of exportations, importations, trade balance, productivity and competitiveness. The investigation will be complemented with an emphasis from the point of national view considering the supply chain of the sector.Universidad del Rosari

What are the Effects of Large-scale Violence on Social and Institutional Trust? Using the Civil War Literature to Understand the Case of Mexico, 2006–2012

Artículo científico en co autoría, publicado en inglés en la Revista Civil Wars, indizada a nivel internacional.El presente trabajo explora el impacto de la violencia de la delincuencia organizada en la confianza ciudadana, principalmente a nivel municipal de México. A través de un análisis multinivel, no se encontraron evidencias concluyentes de una correlación fuerte entre los niveles de violencia organizada a nivel municipal en México y la confianza ciudadana. No obstante, si se detectó una correlación significativa entre la percepción de inseguridad pública y la confianza ciudadana, empero, esta correlación es independiente de la violencia real experimentada.No aplic