61 research outputs found
Barrido de frecuencia en coordenadas de fase Frequency scan on phase-coordinates
El análisis de redes eléctricas ha transitado de modelos en componentes de secuencia a modelos en coordenadas de fase. La formulación del barrido de frecuencia en coordenadas de fase, además de facilitar la modelación más precisa de las redes desequilibradas, permite especificar inyecciones armónicas de cualquier tipo: monofásicas o trifásicas de la secuencia deseada. Por lo que puede estudiarse el efecto de las cargas no lineales de acuerdo a sus características y conexión al circuito. El presente trabajo desarrolla el modelo en coordenadas de fase de una red eléctrica, considerando la representación de bancos de transformadores monofásicos de tres o dos transformadores, así como otros tipos de asimetrías que pueden encontrarse en los sistemas eléctricos de instalaciones industriales, de edificios comerciales o de servicio. El modelo desarrollado se prueba con un ejemplo sencillo de un sistema delta a cuatro hilos que permite destacar las posibilidades del modelo.The electric networks analysis has upgraded from the sequence components frame models to the phase- coordinates frame models. The formulation of the frequency scan method in a phase- coordinates frame, besides allowing for a more accurate modeling of unbalanced networks, allows the specification of harmonic injections of any type: single-phase or three-phase of the desired sequence. Therefore, it is possible to study the effect of the non-linear loads according to its features and connection to the circuit. This paper develops the phase-coordinates model of a distribution power system, considering the representation of three-phase transformer banks of three or two single-phase transformers, as well as other asymmetries that can be found in the electrical systems of industrial plants, commercial or service facilities. The frequency scan based on the presented model is tested with a simple example of a four-wire delta system that highlights the possibilities of the mode
60 Years of Urban Development in Denia and its Influence on the Marineta Cassiana Beach
Everyone is aware of the special relationship that man has with the coast; from the beginning of man- kind, humans have been attracted to the littoral zone for the construction of settlements and the use of its resources. Subsequently, humans have evolved, leaving an increasingly large footprint on this medium. Hence, there is a need to deepen our knowledge to protect against the threat that we ourselves pose. Coastal regression mainly due to the lack of sediment is a global problem. The environmental, economic and social interest makes the study of coastal regression a major problem in the institutions. This article places the study area in Denia (Alicante, Spain). In this population, for some time, there has been concern about the effect on the beaches of the sharp erosion of the coastline. The Marineta Cassiana beach has been chosen for this study because of its special location and the set of elements of the environment. Thus, with respect to the beach study, it is observed that the land beside it is a fully urbanized area, which has suffered due to the pressure of development in this area since 1956, limited as it is by background mountains. Therefore, this study encompasses different aspects of the regression of the coast. To this end, a study of the historical evolution of the beach since 1956 has been carried out. The hydrological modelling of river basins discharging to the beach and their changes due to the alteration of the landscape has been carried out, using dynamics and morphological characterization of the area and an analysis of the erosion of these basins. Also, the historical evolution of the surf on the beach, as well as changes in the morphology of the coast, which have influenced the marine climate, have been taken into account
Routing, Modulation and Spectrum Assignment Algorithm Using Multi-Path Routing and Best-Fit
Producción CientíficaElastic Optical Networks (EONs) are a promising optical technology to deal with the ever-increasing traffic and the vast number of connected devices of the next generation of the Internet, associated to paradigms like the Internet of Things (IoT), the Tactile Internet or the Industry 4.0, to name just a few. In this kind of optical network, each optical circuit or lightpath is provisioned by means of superchannels of variable bandwidth. In this manner, only the necessary bandwidth to accommodate the demand is allocated, improving the spectrum usage. When establishing a connection, the EON control layer determines the modulation format to be used and allocates a portion of the spectrum in a sequence of fibers from the source to the destination node providing the user-demanded bandwidth. This is known as the routing, modulation level and spectrum assignment (RMSA) problem. In this work, we firstly review the most important contributions in that area, and then, we propose a novel RMSA algorithm, multi-path best-fit (MP-BF), which uses a split spectrum multi-path strategy together with a spectrum assignment technique (best-fit), and which jointly exploit the flexibility of EONs. A simulation study has been conducted comparing the performance of EONs when using MP-BF with other proposals from the literature. The results of this study show that, by using MP-BF, the network can increase its performance in terms of lightpath request blocking ratio and supported traffic load, without affecting the energy per bit or the computation time required to find a solution
The Role of Mechanical Properties and Structure of Type I Collagen Hydrogels on Colorectal Cancer Cell Migration
Mechanical interactions between cells and their microenvironment play an important role in determining cell fate, which is particularly relevant in metastasis, a process where cells invade tissue matrices with different mechanical properties. In vitro, type I collagen hydrogels have been commonly used for modeling the microenvironment due to its ubiquity in the human body. In this work, the combined influence of the stiffness of these hydrogels and their ultrastructure on the migration patterns of HCT-116 and HT-29 spheroids are analyzed. For this, six different types of pure type I collagen hydrogels by changing the collagen concentration and the gelation temperature are prepared. The stiffness of each sample is measured and its ultrastructure is characterized. Cell migration studies are then performed by seeding the spheroids in three different spatial conditions. It is shown that changes in the aforementioned parameters lead to differences in the mechanical stiffness of the matrices as well as the ultrastructure. These differences, in turn, lead to distinct cell migration patterns of HCT-116 and HT-29 spheroids in either of the spatial conditions tested. Based on these results, it is concluded that the stiffness and the ultrastructural organization of the matrix can actively modulate cell migration behavior in colorectal cancer spheroids
International Conference on Broadband Communications, Networks and Systems
Producción CientíficaNetwork Function Virtualization (NFV) is considered to be one of the enabling technologies for 5G. NFV poses several challenges, like deciding the virtual network function (VNF) placement and chaining, and adding backup resources to guarantee the survivability of service chains. In this paper, we propose a genetic algorithm that jointly solves the VNF-placement, chaining and virtual topology design problem in WDM metro ring network, with the additional capacity of providing node protection. The simulation results show how important is to solve all of these subproblems jointly, as well as the benefits of using shared VNF and network resources between backup instances in order to reduce both the service blocking ratio and the number of active CPUs.Ministerio de Economía, Industria y Competitividad (grant TEC2017-84423-C3-1-P)Ministerio de Industria, Comercio y Turismo (grant BES 2015-074514)INTERREG V-A España-Portugal (POCTEP) (grant 0677_DISRUPTIVE_2_E)
2020 22nd International Conference on Transparent Optical Networks (ICTON)
Producción CientíficaNetwork Function Virtualization (NFV) is a promising networking paradigm that will ease the network manageability and increase its flexibility, while reducing costs. In this paradigm, operators must solve the Virtual Network Function (VNF) placement and chaining problems. It is also important to provide backup resources to ensure the survivability of the offered services when a node failure happens. In this paper, we compare two different protection approaches to ensure the service resilience: individual VNF protection and end-to-end protection. Results show the benefits in terms of use of computing resources and energy consumption of protecting each VNF individually, compared to the end-to-end protection approach.Ministerio de Economía, Industria y Competitividad (grant TEC2017-84423-C3-1-P)Ministerio de Industria, Comercio y Turismo (fellowship BES-2015-074514)Research network Go2Edge (grant RED2018-102585-T)Interreg V-A Spain-Portugal (POCTEP) programme 2014- 202
Evolution of the passive harmonic filters optimization problem in industrial power systems
Several authors have treated the optimization of passive filters in electric distribution systems. Optimization methods like: sequential quadratic programming (SQP), simulated annealing (SA), differential evolution (DE), artificial neural networks (ANN), particle swarm optimization (PSO), genetic algorithm (GA), etc., have been employed for optimizing certain configurations of passive filters. These optimization methods have been employed to solve several formulations of the problem of the project of filters. These formulations can be classified in: formulations of one or several objectives. The objective of the present work is to show the evolution of the formulation of this problem in the lasts years respect to the objective functions and constraints used. This analysis shows how the formulations employed have been upgraded from single-objective to multi-objective formulations to achieve a better representation of this complex problem
2019 21st International Conference on Transparent Optical Networks (ICTON)
Producción Científica5G technology will provide networks with high-bandwidth, low latency and multitenancy. The integration of computing and storage resources in the edge of the fronthaul network, i.e., multi-access edge computing (MEC), will allow to instantiate some virtual network functions (VNF) in those computing resources. The backhaul of 5G networks will be based on optical technology, in particular WDM, due to its high capacity and flexibility. In this paper, we analyse the problem of VNF-provisioning in a metro ring-topology network equipped with MEC resources and with a WDM network connecting the edge nodes. In contrast to previous proposals, the method decides where VNFs must be instantiated but also the design of the virtual topology for the WDM metro network in order to reduce the service blocking ratio and the number of resources in operation.Ministerio de Economía, Industria y Competitividad (project TEC2017-84423-C3-1-P)Ministerio de Industria, Energía y Turismo (project BES-2015-074514
Inteligencia artificial para la multi-clasificación de fauna en fotografías automáticas utilizadas en investigación científica
El manejo de ambientes naturales, ya sea para conservación o producción, requiere de una profunda comprensión de la vida silvestre. El número, la ubicación y el comportamiento de los animales salvajes es uno de los principales objetos de estudio en ecología y vida silvestre.
El uso de cámaras trampa ofrece la oportunidad de recopilar rápidamente grandes cantidades de fotografías que -sin la presencia humana- registran a la fauna en su hábitat natural, evitando factores que alteren su comportamiento.
En Tierra del Fuego, Argentina, se desarrollan investigaciones sobre el uso del bosque por parte de distintos herbívoros (guanacos, vacas, ovejas) para optimizar el manejo y proteger dichos ecosistemas naturales.
Si bien las cámaras trampa permiten la obtención de millones de imágenes, la interpretación de tales fotografías representa un problema de escala para el procesamiento manual. Así, gran parte del valioso conocimiento en estos enormes repositorios de datos sigue sin ser aprovechado.
Las Redes Neuronales y el Deep Learning son áreas de estudio dentro la Inteligencia Artificial, durante la última década estas dos disciplinas han hecho cuantiosos aportes en el ámbito del reconocimiento de imágenes de gran relevancia a nivel mundial.
Los estudios ecológicos y de conservación de la vida silvestre, pueden combinarse con estas nuevas tecnologías para extraer información importante a partir de las fotografías obtenidas por cámaras trampa, con el objeto de aportar a la comprensión de distintos procesos naturales y mejorar el manejo de las áreas silvestres implicadas.
Nuestro proyecto busca desarrollar modelos de redes neuronales para clasificar especies de animales en fotografías obtenidas mediante cámaras trampa, para resolver problemas de gran volumen en investigación científica.Red de Universidades con Carreras en Informátic
CSCI 2017
Producción CientíficaElastic Optical Networks (EON) are seen as an essential technology to implement the backhaul of Future Internet allowing the deployment of emerging paradigms like the Internet of Things (IoT), Tactile Internet, or Industry 4.0. When designing those Elastic Optical Networks (EONs), the Routing and Spectrum Assignment (RSA) problem has to be solved. In this paper, we analyse the effect of using two types of flexibility in a well‑known RSA method. A simulation study will be presented with the main results of this comparison.Ministerio de Economía, Industria y Competitividad (Projects TEC2014-53071-C3-2-P, TEC2015-71932-REDT)Ministerio de Educación, Cultura y Deporte (Proyect BES-2015-074514
- …