New Modulation Technique to Mitigate Common Mode Voltage Effects in Star-Connected Five-Phase AC Drives

Star-connected multiphase AC drives are being considered for electromovility applications such as electromechanical actuators (EMA), where high power density and fault tolerance is demanded. As for three-phase systems, common-mode voltage (CMV) is an issue for multiphase drives. CMV leads to shaft voltages between rotor and stator windings, generating bearing currents which accelerate bearing degradation and produce high electromagnetic interferences (EMI). CMV effects can be mitigated by using appropriate modulation techniques. Thus, this work proposes a new Hybrid PWM algorithm that effectively reduces CMV in five-phase AC electric drives, improving their reliability. All the mathematical background required to understand the proposal, i.e., vector transformations, vector sequences and calculation of analytical expressions for duty cycle determination are detailed. Additionally, practical details that simplify the implementation of the proposal in an FPGA are also included. This technique, HAZSL5M5-PWM, extends the linear range of the AZSL5M5-PWM modulation, providing a full linear range. Simulation results obtained in an accurate multiphase EMA model are provided, showing the validity of the proposed modulation approach.This work has been supported in part by the Government of the Basque Country within the fund for research groups of the Basque University system IT978-16 and in part by the Government of the Basque Country within the research program ELKARTEK as the project ENSOL (KK-2018/00040)

How important is the European economic and monetary union in the foreign trade with the EU-27 countries? Empirical evidence from Spain

This paper analyzes the effect of the European Economic and Monetary Union on export flows from a Spanish region (Castilla y Leon) to the EU-27 countries during the last years Applying static panel data estimation technique, this study finds that exporter and importer incomes, exporter population, distance, and a common land border are the main explanatory factors of exports from this Spanish region. Moreover, the EU membership of the importer country only caused positive and significant effects between 1994 and 1996, whereas the EMU membership reduced export flows from Castilla y Leon to the European countries during the whole period.peer-reviewe

Utilidades de Matlab para la gestión de los datos crudos obtenidos por un receptor GPS con tecnología SiRF

The normal users only uses some basic information for their location, the GPS receivers sends many other data that are useful for experts users. With a commercial receiver from Royaltek, a Bluetooth transmitter and Matlab mathematical software, we've created a series of functions for extracting raw data from the receiver and for check the correct interpretation and conversion. The objective is the users could get this data as from low-cost receiver. In this this project will find a brief summary of the GPS system, explanations on the operation or structure of the SiRF protocols, you will also find a small descriptive guide to the transmission of data from the GPS system, that's is important to get interoperability between SIRF protocol with the GPS frames. Also provides an experiment to show the use of such routines in an academic and as a foundation on which to base future work and develop or improve the applications that employ

Groove gap waveguide in metallized 3D-printed plastic and in mechanized aluminium in Ka band

This paper conducts a comparison between two different manufacturing technologies for a prototype in Groove Gap Waveguide. Both technologies are metallized 3D-printed plastic and mechanized aluminium. The prototype is a straight section with transitions to WR-28 that works in the frequency band from 28 to 30 GHz. The main properties of the technologies in terms of losses, weight and ease of manufacture are presented, as well as measurements for both prototypes together with simulations

Identification of predictive factors of the degree of adherence to the Mediterranean diet through machine-learning techniques

Food consumption patterns have undergone changes that in recent years have resulted in serious health problems. Studies based on the evaluation of the nutritional status have determined that the adoption of a food pattern-based primarily on a Mediterranean diet (MD) has a preventive role, as well as the ability to mitigate the negative effects of certain pathologies. A group of more than 500 adults aged over 40 years from our cohort in Northwestern Spain was surveyed. Under our experimental design, 10 experiments were run with four different machine-learning algorithms and the predictive factors most relevant to the adherence of a MD were identified. A feature selection approach was explored and under a null hypothesis test, it was concluded that only 16 measures were of relevance, suggesting the strength of this observational study. Our findings indicate that the following factors have the highest predictive value in terms of the degree of adherence to the MD: basal metabolic rate, mini nutritional assessment questionnaire total score, weight, height, bone density, waist-hip ratio, smoking habits, age, EDI-OD, circumference of the arm, activity metabolism, subscapular skinfold, subscapular circumference in cm, circumference of the waist, circumference of the calf and brachial area

Distribución y Aspectos Poblacionales del Lobo Ibérico en la Provincia de Ourense / Distribution and Population Aspects of the Iberian Wolf in the Province of Ourense, Spain

Para determinar el área de distribución del lobo en la provincia de Ourense (noroeste de España) se realizaron prospecciones de campo consistentes en itinerarios de muestreo para localizar indicios y se enviaron cuestionarios a los Agentes del Servicio de Conservación de la Naturaleza de la Xunta de Galicia y a las Sociedades de Cazadores del área de estudio. Los resultados se registraron sobre cuadrículas U.T.M. 10x10 Km. Se constata presencia del lobo en el 79,2% de las cuadrículas estudiadas, estimando el área de distribución en la provincia en 6.400 km2. Para la localización de los grupos familiares inicialmente se prospectó el territorio a nivel de cuadrículas U.T.M. 10x10 Km y en función de los resultados y la información recibida se eligieron determinadas zonas para realizar estaciones de escucha y espera. Determinamos durante el periodo de estudio la existencia de 25 grupos familiares. La densidad estimada en la provincia es de 2,10 – 3,28 lobos /100 km2. De los casos de mortalidad conocidos entre enero de 1999 y abril de 2002 (n=37), un elevado porcentaje se debió a atropellos (70,27%) principalmente en dos vías concretas y un 8,10% correspondió a envenenamientos. Actualmente la densidad del lobo en Ourense es superior a la obtenida en provincias limítrofes, pero amenazas de origen antrópico tanto directas (veneno, persecución ilegal...) como indirectas (incendios forestales, grandes infraestructuras viales, parques eólicos...) pueden estar condicionando la existencia de grupos familiares e incluso la presencia de la especie en determinadas zonas

New antenna topologies for 5G communication systems

This paper presents new antenna topologies for 5G communication systems. The objective is the study of low losses distribution network technologies and the radiating elements for low profile antennas for 5G applications. Different technologies are considered as PCB technology, LTCC technology and metallized 3D printing in terms of design procedures, transmission losses and manufacturing processes in order to contribute to these types of technologies. Different designs and prototypes are done to validate these antennas for 5G communication system

Identificación y caracterización de una deshalogenasa de Populus

Identificación en el genoma de Populus de una proteína con actividad deshalogenasa y análisis de su actividad enzimática

Límites a los contratos estatales frente a los regímenes especiales de contratación en Colombia. Estudio de casos : empresas sociales del estado y universidades

En el presente trabajo de investigación se aborda una de las problemáticas más sensibles del Estado colombiano como lo es la contratación estatal, sobre todo por qué ciertos tipos de contratación entran a formar parte de los denominados regímenes especiales las cuales son diferentes a las convencionales, no por ello gozan de total libertad por lo que son objeto de control por parte del Estado. Se diferencian al poseer independencia de contratación, además estos regímenes son malinterpretados por las personas que tienen a su cargo las directrices de la misma, en muchos de los casos desbordando sus funciones, por lo que se les pueden considerar como ruedas sueltas de la administración por tal razón se realiza la presente investigación en busca de determinar si los regímenes especiales se le aplica una diferencia en la contratación estatal relacionados con los órganos de control que los vigilan. Para ello el presente estudio se diseñó un estudio descriptivo el cual permitiera analizar la normativa vigente relacionada con el comportamiento de los regímenes especiales Colombia, siendo este tipo de estudio el adecuado cuando apenas se considera un plano de exploración del problema, tal como lo afirman muchos investigadores en el presente campo. También para imprimirle mayor rigor metodológico, se parte de una hipótesis concreta para que la investigación se dirija en una dirección, la que permita asegurar unos resultados fiables. Se utiliza el método inductivo porque la inducción permite llegar a generalizaciones, pero soportados en un análisis cualitativo por tratarse tan solo de textos.In this research one of the most sensitive issues of the Colombian state as it is government procurement, especially why certain types of recruitment addresses become part of the so-called special regimes which are different from conventional, not therefore they enjoy full freedom so they are monitored by the state. They differ by possessing independence contracting addition these regimes are misinterpreted by people who are responsible for the guidelines of it, in many cases exceed their duties, so they can be considered them as loose wheels of administration this reason this research is done in search to determine whether the special schemes is applied to a difference in government procurement related to the supervisory bodies that monitor. To do this study a descriptive study which possible to analyze the current regulations related to the behavior of special regimes Colombia was designed, and this type of study appropriate when hardly considered a scanning plane of the problem, as many say researchers in this field. Also to impart greater methodological rigor, is part of a specific hypothesis for research is directed in one direction, which would ensure reliable results. the inductive method is used because induction allows to generalize, but supported on a qualitative analysis because it only text