Error control in simplification before generation algorithms for symbolic analysis of large analogue circuits

Circuit reduction is a fundamental first step in addressing the symbolic analysis of large analogue circuits. A new algorithm for simplification before generation is presented which is very efficient in terms of speed and the amount of circuit reduction, and solves the accuracy problems of previously reported approaches

An error-controlled methodology for approximate hierarchical symbolic analysis

Limitations of existing approaches for symbolic analysis of large analog circuits are discussed. To address their solution, a new methodology for hierarchical symbolic analysis is introduced. The combination of a hierarchical modeling technique and approximation strategies, comprising circuit reduction, graph-based symbolic solution of circuit equations and matrix-based error control, provides optimum results in terms of speech and quality of results.European Commission ESPRIT 21812Comisión Interministerial de Ciencia y Tecnología TIC97-058

Analysing temporal performance profiles of UAV operators using time series clustering

The continuing growth in the use of Unmanned Aerial Vehicles (UAVs) is causing an important social step forward in the performance of many sensitive tasks, reducing both human and economical risks. The work of UAV operators is a key aspect to guarantee the success of this kind of tasks, and thus UAV operations are studied in many research fields, ranging from human factors to data analysis and machine learning. The present work aims to describe the behaviour of operators over time using a profile-based model where the evolution of the operator performance during a mission is the main unit of measure. In order to compare how different operators act throughout a mission, we describe a methodology based of multivariate-time series clustering to define and analyse a set of representative temporal performance profiles. The proposed methodology is applied in a multi-UAV simulation environment with inexperienced operators, obtaining a fair description of the temporal behavioural patterns followed during the course of the simulation

Analysing temporal performance profiles of UAV operators using time series clustering

The continuing growth in the use of Unmanned Aerial Vehicles (UAVs) is causing an important social step forward in the performance of many sensitive tasks, reducing both human and economical risks. The work of UAV operators is a key aspect to guarantee the success of this kind of tasks, and thus UAV operations are studied in many research fields, ranging from human factors to data analysis and machine learning. The present work aims to describe the behaviour of operators over time using a profile-based model where the evolution of the operator performance during a mission is the main unit of measure. In order to compare how different operators act throughout a mission, we describe a methodology based of multivariate-time series clustering to define and analyse a set of representative temporal performance profiles. The proposed methodology is applied in a multi-UAV simulation environment with inexperienced operators, obtaining a fair description of the temporal behavioural patterns followed during the course of the simulation

A study on performance metrics and clustering methods for analyzing behavior in UAV operations

Unmanned Aerial Vehicles (UAVs) are starting to provide new possibilities to human societies and their demand is growing according to the new industrial application fields for these revolutionary tools. The current systems are still evolving, specially from an Artificial Intelligence perspective, which is increasing the different tasks that UAVs can perform. However, the current state still requires a strong human supervision. As a consequence, a good preparation for UAV operators is mandatory due to some of their applications might affect human safety. During the training process, it is important to measure the performance of these operators according to different factors that can help to decide what operators are more suitable for different kinds of missions creating operator profiles. Having this goal in mind, this work aims to present an extensive and robust methodology to automatically extract different performance profiles from the training process of operators in an UAV simulation environment. Our method combines the definition of a set of performance metrics with clustering techniques to define operators profiles, ensuring that the behavior discrimination is suitable and consistent

QBD Processes Associated with Jacobi–Koornwinder Bivariate Polynomials and Urn Models

The work of the first author was partially supported by FEDER/Junta de Andalucía under the Research Project A-FQM-246-UGR20; MCIN/AEI 10.13039/501100011033 and FEDER funds by PGC2018-094932-B-I00; and IMAG-María de Maeztu Grant CEX2020-001105-M. The work of the second author was partially supported by PAPIIT-DGAPA-UNAM Grant IN106822 (México) and CONACYT Grant A1-S-16202 (México).We study a family of quasi-birth-and-death (QBD) processes associated with the so-called first family of Jacobi–Koornwinder bivariate polynomials. These polynomials are orthogonal on a bounded region typically known as the swallow tail. We will explicitly compute the coefficients of the three-term recurrence relations generated by these QBD polynomials and study the conditions under we can produce families of discrete-time QBD processes. Finally, we show an urn model associated with one special case of these QBD processes.IMAG-María de Maeztu CEX2020-001105-MConsejo Nacional de Ciencia y Tecnología A1-S-16202 CONACYTDirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México IN106822 DGAPA, UNAMFondo de Cooperación Internacional en Ciencia y Tecnología FONCICYTEuropean Regional Development Fund ERDFJunta de Andalucía A-FQM-246-UGR20, PGC2018-094932-B-I0

Una contribución al estudio racial del cerdo Mamellado Uruguayo

In spite of the persistence in Uruguay of pigs belonging to the wattled pig breed, no adequate attention had ever been paid to them. The wattles appear associated with ancestries of the Iberian pig (Spanish and Portuguese) and to other breeds pertaining to the Mediterranean trunk, being rare in the Celtic trunk. This scientific peculiarity, together with reasons of adaptation and rusticity (production), environmental (association with specific ecosystems) and historical-cultural role makes the study of this genetic resource justifiable. The Team of the Red XII-H CYTED of Uruguay was established and has made a series of consultations and interviews to locate the farms in which this type of pig is established and other information that will help clarify their present situation, origin and historical evolution. Preliminary information obtained in the census indicates that the Uruguayan Wattled Pigs (UWP) whilst critical in terms of numbers are widely distributed geographically, living in varying ecosystems and living together with small and medium producers that have maintained the animals as a novelty as well as for self consumption (sausage making). Within the framework of a complete racial study the Team is planning to carry out the morphologic characterization of the animals and a genetic study, in order to determine the distance between the Uruguayan wattled pig and other breeds from the Mediterranean trunk. Productive parameters and the most favourable exploitation conditions for obtaining high quality products in sustainable systems that make geographically unfavourable areas more profitable, will also be analysed.A pesar de que aún persisten en el Uruguay cerdos de la raza Mamellado Uruguayo, nunca se les ha dedicado la atención adecuada. Las mamellas aparecen asociadas a variedades ancestrales del cerdo Ibérico (español y portugués) y a otras razas pertenecientes al tronco Mediterráneo, siendo muy raras en el tronco Celta. Esta peculiaridad específica, junto con razones de adaptación y rusticidad (producción), ambiente (asociación con ambientes específicos) y el papel histórico-cultural justifican sobradamente este estudio. El equipo uruguayo dela Red CYTED XII-H ha realizado una serie de consultas y entrevistas para localizar las granjas donde estos cerdos están establecidos así como otra información que nos ayudará a clarificar su situación actual, su origen y su evolución histórica. La información preliminar obtenida sobre sus censos indica que el Cerdo Mamellado Uruguayo se encuentra en estado crítico. Además se encuentra distribuido geográficamente de una manera amplia habitando variados ecosistemas en explotaciones medias y pequeñas que han mantenido a estos animales por afición o para autoconsumo (fabricación de chacinados). Dentro de la tarea de un estudio racial completo nuestro equipo está planeando llevar a cabo la caracterización morfológica de estos animales y su estudio genético, en orden a determinar la distancia entre esta raza y otros miembros del Tronco Mediterráneo. También son analizados los parámetros productivos y las condiciones de explotación más favorables para obtener productos de alta calidad en sistemas sostenibles que hacen rentables a las áreas más desfavorecidas

Variational approach for walking solitons in birefringent fibres

We use the variational method to obtain approximate analytical expressions for the stationary pulselike solutions in birefringent fibers when differences in both phase velocities and group velocities between the two components and rapidly oscillating terms are taken into account. After checking the validity of the approximation we study how the soliton pulse shape depends on its velocity and nonlinear propagation constant. By numerically solving the propagation equation we have found that most of these stationary solutions are stable.Comment: LaTeX2e, uses graphicx package, 23 pages with 8 figure