4,642 research outputs found

    Glasius bio-inspired neural networks based UV-C disinfection path planning improved by preventive deadlock processing algorithm

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    The COVID-19 pandemic made robot manufacturers explore the idea of combining mobile robotics with UV-C light to automate the disinfection processes. But performing this process in an optimum way introduces some challenges: on the one hand, it is necessary to guarantee that all surfaces receive the radiation level to ensure the disinfection; at the same time, it is necessary to minimize the radiation dose to avoid the damage of the environment. In this work, both challenges are addressed with the design of a complete coverage path planning (CCPP) algorithm. To do it, a novel architecture that combines the glasius bio-inspired neural network (GBNN), a motion strategy, an UV-C estimator, a speed controller, and a pure pursuit controller have been designed. One of the main issues in CCPP is the deadlocks. In this application they may cause a loss of the operation, lack of regularity and high peaks in the radiation dose map, and in the worst case, they can make the robot to get stuck and not complete the disinfection process. To tackle this problem, in this work we propose a preventive deadlock processing algorithm (PDPA) and an escape route generator algorithm (ERGA). Simulation results show how the application of PDPA and the ERGA allow to complete complex maps in an efficient way where the application of GBNN is not enough. Indeed, a 58% more of covered surface is observed. Furthermore, two different motion strategies have been compared: boustrophedon and spiral motion, to check its influence on the performance of the robot navigation

    Defining Effectiveness Using Finite Sets A Study on Computability

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    AbstractThis paper studies effectiveness in the domain of computability. In the context of model-theoretical approaches to effectiveness, where a function is considered effective if there is a model containing a representation of such function, our definition relies on a model provided by functions between finite sets and uses category theory as its mathematical foundations. The model relies on the fact that every function between finite sets is computable, and that the finite composition of such functions is also computable. Our approach is an alternative to the traditional model-theoretical based works which rely on (ZFC) set theory as a mathematical foundation, and our approach is also novel when compared to the already existing works using category theory to approach computability results. Moreover, we show how to encode Turing machine computations in the model, thus concluding the model expresses at least the desired computational behavior. We also provide details on what instances of the model would indeed be computable by a Turing machine

    FIBROUS HYPERPLASIA ASSOCIATED WITH CHILDHOOD TRAUMA: CASE REPORT

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    This paper describes a case of inflammatory fibrous hyperplasia in an 11-year-old child caused by chronic mucosal irritation due to abnormal positioning of the central incisor. A male child, together with his guardian, sought specialized dental care in the municipality of Jaru, Rondônia, Brasil referred by a public service dentist, complaining of gingival enlargement in the region of the upper right central incisor. The patient reported having suffered dental trauma in the region, which resulted in the palatoversion of the element 11, which had two thirds of the crown covered by a rounded growth with firm consistency and smooth surface. The treatment performed was surgical excision of the lesion, later referred for histopathological analysis that confirmed the diagnostic hypothesis of inflammatory fibrous hyperplasia. Thus, it is possible to acknowledge that the tooth outside its normal position can cause gingival irritation and cause inflammatory fibrous hyperplasia even in young people

    Análisis del golpeo de balón y su relación con el salto vertical en futbolistas juveniles de alto nivel

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    El rendimiento en acciones explosivas como el golpeo de balón y el salto vertical es de gran relevancia en el fútbol. Los objetivos del presente estudio fueron: 1) Estudiar la secuencia del golpeo en futbolistas jóvenes de alto nivel, y, 2) analizar las posibles relaciones existentes entre el golpeo de balón y el salto vertical. 21 jugadores de alto nivel (16,1 ± 0,2 años) llevaron a cabo un test de salto vertical con contramovimiento (CMJ) y un test de golpeo de balón con la máxima potencia. Los datos fueron registrados mediante una plataforma de fuerzas (Dinascan IBV) y un sistema de captura automática del movimiento (Vicon). Con este estudio, se aporta información sobre la cinemática del golpeo en futbolistas juveniles de alto nivel. En función de los resultados obtenidos, se puede afirmar que la secuencia temporal de máximos de velocidad sucede desde el extremo más proximal al más distal, incrementándose la velocidad. La ausencia de relación entre el golpeo y el salto sugiere el trabajo de fuerza explosiva específico para la mejora de cada una de ellas

    The application of biomechanics to penalty corner drag-flick training: a case of Study

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    The penalty corner is one of the most important game situations in field hockey with one third of all goals resulting from this tactical situation. The aim of this study was to develop and apply a training method, based on previous studies, to improve the drag- flick skill on a young top-class field hockey player. A young top-class player exercised three times per week using specific drills over a four week period. A VICON optoelectronic system (Oxford Metrics, Oxford, UK) was employed to capture twenty drag-flicks, with six cameras sampling at 250 Hz, prior and after the training period. In order to analyze pre- and post-test differences a dependent t-test was carried out. Angular velocities and the kinematic sequence were similar to previous studies. The player improved (albeit not significantly) the angular velocity of the stick. The player increased front foot to the ball at T1 (p < 0.01) and the drag-flick distances. The range of motion from the front leg decreased from T1 to T6 after the training period (p < 0.01). The specific training sessions conducted with the player improved some features of this particular skill. This article shows how technical knowledge can help with the design of training programs and whether some drills are more effective than others

    Comparative study of Fusarium communities from soil and rhizoplane of melon plants from tropical farming soils.

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    Fifty-nine rhizospheric soil samples from twenty different melon farms of Guatemala and Honduras were analysed to study the Fusarium species present in the soil and those developing on roots surfaces

    Effect of positioning on the accuracy of decision making of association football top-class referees and assistant referees during competitive matches

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    The aim of this study was to examine the effect of positioning on the correctness of decision making of top-class referees and assistant referees during international games. Match analyses were carried out during the Fe´de´ration Internationale de Football Association (FIFA) Confederations Cup 2009 and 380 foul play incidents and 165 offside situations were examined. The error percentage for the referees when indicating the incidents averaged 14%. The lowest error percentage occurred in the central area of the field, where the collaboration of the assistant referee is limited, and was achieved when indicating the incidents from a distance of 11–15 m, whereas this percentage peaked (23%) in the last 15-min match period. The error rate for the assistant referees was 13%. Distance of the assistant referee to the offside line did not have an impact on the quality of the offside decision. The risk of making incorrect decisions was reduced when the assistant referees viewed the offside situations from an angle between 46 and 608. Incorrect offside decisions occurred twice as often in the second as in the first half of the games. Perceptual-cognitive training sessions specific to the requirements of the game should be implemented in the weekly schedule of football officials to reduce the overall error rate

    Evaluación de la incidencia de enfermedades criptogámicas foliares en cereales de invierno y primavera en España. Periodo 1993-1996.

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    El trabajo presenta los resultados de evaluar las micosis foliares de los cereales durante tres campañas de cultivo consecutivas: 1993-94; 1994-95 y 1995-96. En la campaña 1993-1994 fueron evaluadas 154 variedades de trigo, triticale y cebada. Durante 1994-1995 se valoraron 145 variedades. En 1995-1996 fueron 161 las prospectadas y se ampliaron las observaciones a 9 cultivares de avena. Las variedades estuvieron cultivadas en ocho toponimias cerealícolas de España. Los resultados pusieron de manifiesto que las enfermedades más importantes fueron: Septoria tritici, Blumeria graminis f.sp.tritici, Puccinia recondita f.sp.tritici y Pyrenophora teres, en trigo blando o harinero(primavera e invierno),trigo duro y triticale. Muy discreta fue la presencia de la roya amarilla (Puccinia striiformis f.sp.tritici). En cebada (primavera y verano), Pyrenophora teres, Rhynchosporium secalis y Blumeria graminis f.sp.hordei fueron las especies fúngicas más importantes. Para las variedades de avena fue Puccinia coronata (roya coronada la enfermedad más frecuente. No pudieron establecerse diferencias entre variedades por su resistencia a alguno de los patógenos encontrados

    Valoración de la Fuerza Explosiva General y Específica en Futbolistas Juveniles de Alto Nivel.

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    La fuerza explosiva es una capacidad física fundamental en el fútbol, por lo que su valoración resulta importante para el control y planificación del entrenamiento. El objetivo de este estudio fue valorar la Fuerza explosiva general y específica en futbolistas juveniles de alto nivel. 21 jugadores pertenecientes a un club de alto nivel (16,1 ± 0,2 años; 1,77 ± 0,06 m; 67,7 ± 6,3 kg) llevaron a cabo un test general de fuerza explosiva (salto vertical con contra movimiento -CMJ) y un test específico (golpeo de balón con la máxima potencia), obteniéndose, a través de una plataforma de fuerzas Dinascan IBV y de un sistema de captura automática del movimiento en 3D Vicon, datos de diversas variables relacionadas con la fuerza explosiva, siendo posteriormente registrados en una hoja de cálculo Excel diseñada al efecto. Se observa que los tests llevados a cabo proporcionan, en un corto periodo de tiempo, una información de gran relevancia para el control y la planificación del entrenamiento con el objetivo de intentar optimizar el rendimiento de los futbolistas

    El patrón de movimiento en el swing de golf en jóvenes promesas

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    Introducción: El swing de golf es una destreza que podríamos catalogar de golpeo de velocidad donde el objetivo es que la cara del palo alcance la máxima velocidad en el momento del impacto. Objetivos: Analizar la secuencia temporal del swing de golf y determinar su patrón de movimiento. Métodos: Se han analizado biomecánicamente 10 golpeos de 4 jugadores promesas, mediante el sistema de fotogrametría 3D Vicon Oxford Metrics® de captura automática. Resultados: En primer lugar se ha podido comprobar que los valores absolutos de velocidades lineales eran mayores en los chicos que en las chicas. El análisis de las 2 fases del swing indica que la fase de aceleración downswing presenta una variabilidad menor que el backswing. El análisis de la secuencia temporal de máximos alcanzados en las velocidades lineales de los segmentos muestra que sus acciones siguen un orden diferente en función del sexo. La secuencia en los chicos empieza por el movimiento de caderas y sigue con el codo izquierdo, el hombro izquierdo y el palo; en las chicas, las caderas y el codo izquierdo actúan simultáneamente seguidos del hombro izquierdo y del palo. En cambio, las secuencias de velocidades angulares encontradas seguían en ambos sexos el mismo orden: primero el giro de caderas, luego el giro de hombros y por último la aceleración del palo. Esta secuencia de acciones se encontraba más separada en el tiempo en los hombres que en las mujeres. Conclusiones: Se hallaron los patrones del movimiento mediante fórmulas discriminantes en ambos sexos, capaces de predecir si el golpeo sería “bueno” o “malo” siguiendo el criterio de rendimiento marcado en la velocidad de la cabeza del palo. Introduction: The golf swing is a skill that could be classified as high velocity hitting in which the main goal is that the head of the golf club reaches its maximum velocity at the moment of impact. Aims: To analyze the timing sequence of the golf swing and to identify the movement pattern of this skill. Methods: Ten golf swings executed by four young players were biomechanically analyzed. Automatic capture with Vicon Oxford Metrics® was used. Results: The absolute values of the linear velocities were higher in men than in women. In the interval analysis, the downswing showed less variation than the backswing. Analysis of the maximum speed timing sequence revealed a different order depending on gender. In men, the sequence started with the hip movement, followed by the left elbow, left shoulder and the club head. In women, the hips and left elbow moved simultaneously, followed by the left shoulder and the club head. In contrast, the angular velocity sequences followed the same order in both genders: first the hip turn, then the shoulder turn, and finally the golf club head acceleration. These key events were more separated in the time line in men than in women. Conclusions: Movement patterns were found through discriminatory formulae in both genders, which were able to predict whether the golf swing was “good” or “bad”, taking the club head speed as the performance criterion
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