2,101 research outputs found

    Estimating adaptive setpoint temperatures using weather stations

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    Reducing both the energy consumption and CO 2 emissions of buildings is nowadays one of the main objectives of society. The use of heating and cooling equipment is among the main causes of energy consumption. Therefore, reducing their consumption guarantees such a goal. In this context, the use of adaptive setpoint temperatures allows such energy consumption to be significantly decreased. However, having reliable data from an external temperature probe is not always possible due to various factors. This research studies the estimation of such temperatures without using external temperature probes. For this purpose, a methodology which consists of collecting data from 10 weather stations of Galicia is carried out, and prediction models (multivariable linear regression (MLR) and multilayer perceptron (MLP)) are applied based on two approaches: (1) using both the setpoint temperature and the mean daily external temperature from the previous day; and (2) using the mean daily external temperature from the previous 7 days. Both prediction models provide adequate performances for approach 1, obtaining accurate results between 1 month (MLR) and 5 months (MLP). However, for approach 2, only the MLP obtained accurate results from the 6th month. This research ensures the continuity of using adaptive setpoint temperatures even in case of possible measurement errors or failures of the external temperature probes.Spanish Ministry of Science, Innovation and Universities 00064742/ITC-20133094Spanish Ministry of Economy, Industry and Competitiveness BIA 2017-85657-

    Coronectomy of impacted mandibular third molars: a meta-analysis and systematic review of the literature

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    Background: Coronectomy is an alternative to complete removal of an impacted mandibular third molar. Most authors have recommended coronectomy to prevent damage to the inferior alveolar nerve during surgical extraction of lower third molars. The present study offers a systematic review and metaanalysis of the coronectomy technique. Material and Methods: A systematic review and meta-analysis was performed based on a PubMed and Cochrane databases search for articles published from 2014 and involving coronectomy of mandibular third molars located near the inferior alveolar nerve canal, with a minimum of 10 cases and a minimum follow-up period of 6 months. After application of the inclusion and exclusion criteria, a total of 12 articles were included in the study. Results and Discussion: Coronectomy results in significantly lesser loss of sensitivity of the inferior alveolar nerve and prevents the occurrence of dry socket. No statistically significant differences were observed in the incidence of pain and infection between coronectomy and complete surgical extraction. After coronectomy, the remaining tooth fragment migrates an average of 2 mm within two years. Conclusions: Coronectomy is indicated when the mandibular third molar is in contact with the inferior alveolar nerve and complete removal of the tooth may cause nerve damage

    On the use of biased-randomized algorithms for solving non-smooth optimization problems

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    Soft constraints are quite common in real-life applications. For example, in freight transportation, the fleet size can be enlarged by outsourcing part of the distribution service and some deliveries to customers can be postponed as well; in inventory management, it is possible to consider stock-outs generated by unexpected demands; and in manufacturing processes and project management, it is frequent that some deadlines cannot be met due to delays in critical steps of the supply chain. However, capacity-, size-, and time-related limitations are included in many optimization problems as hard constraints, while it would be usually more realistic to consider them as soft ones, i.e., they can be violated to some extent by incurring a penalty cost. Most of the times, this penalty cost will be nonlinear and even noncontinuous, which might transform the objective function into a non-smooth one. Despite its many practical applications, non-smooth optimization problems are quite challenging, especially when the underlying optimization problem is NP-hard in nature. In this paper, we propose the use of biased-randomized algorithms as an effective methodology to cope with NP-hard and non-smooth optimization problems in many practical applications. Biased-randomized algorithms extend constructive heuristics by introducing a nonuniform randomization pattern into them. Hence, they can be used to explore promising areas of the solution space without the limitations of gradient-based approaches, which assume the existence of smooth objective functions. Moreover, biased-randomized algorithms can be easily parallelized, thus employing short computing times while exploring a large number of promising regions. This paper discusses these concepts in detail, reviews existing work in different application areas, and highlights current trends and open research lines

    Analysis of the generation, disposition and environmental effects of used tires of passenger vehicles in two localities of Barranquilla

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    Introduction: There is a problem in the city of Barranquilla regarding in the treatment of the solid waste product of the generation of used tires, along with its disposition and subsequent environmental effects. As of December of 2018, date on which this project is being carried on; there is no official system regulating the generation and proper disposal of used tires. Although there are laws that oversee this issue, mandated by the National Constitution, and preliminary projects that formulate systems for the proper collection and disposal of waste tires [1], most of them made in the capital city of Bogota, they are not properly reinforced or implemented to date, and most regulations only refer to the overall effects of the improper disposal of waste on the environment. Objective: analyze the current status of the generation, disposition and environmental effects of used tires in the city, focusing in the Riomar and Northern Historic Centre, as the field data on which the analysis is based on was collected there, due most concentration of establishments. This paper explores existing alternatives and processes for handling the disposed used tires enabling the use of the materials and compounds within its structure for efficient uses of this resource while diminishing its impact on the environment. Method: The analysis is going to identify the current factors that influence the generation of used tires and expand upon it with a forecast for the generation of used tires in the next 5 years, covering the year interval from 2019 to 2023. Following the forecast, will foreground the existing methods for the handling of the disposed tires, along with the environmental effects generated by the improper disposal of this type of waste. Results: There is a growing positive relationship in the historical data regarding the relation of registered vehicles and the year. In the same way, the survey shows that the highest concentration of the sample discards the tires used in garbage dumps. Conclusion: According to the results of the forecast and the surveys, the importance of controlling the disposal of used tires is highlighted, therefore it is established that the best practice to reduce or eliminate the used tires is co-processing for cement kilns and mechanical crushing by its zero emissions factorIntroducción: Existe un problema en la ciudad de Barranquilla que involucra el tratamiento de los residuos sólidos que son producto de la generación de llantas usadas, junto con su disposición y los efectos ambientales. Hasta diciembre de 2018, fecha en que se desarrolló este proyecto, no hay ningún sistema oficial que se encargue de la regulación de la generación y adecuada disposición de las llantas usadas. Aunque hay leyes que cubren esta problemática y existen estudios preliminares que plantean sistemas para la adecuada colección y disposición de llantas usadas [1], la mayoría de estos no son apropiadamente reforzados o implementados a la fecha, y gran parte de las regulaciones solamente se refieren a los efectos generales de la disposición inadecuada de desechos en el ambiente. Objetivo: Analizar el estado actual de la generación, la disposición y los efectos medioambientales que causan las llantas usadas en la cuidad, enfocándose en las localidades de Riomar y Norte Centro Histórico de la cuidad, ya que allí fueron recolectados los datos debido a la mayor concentración de establecimientos. Este artículo explora las diferentes alternativas y procesos que se usan para el manejo y disposición de las llantas usadas, permitiendo el uso de los materiales y compuestos de su estructura para el aprovechamiento eficiente de este recurso, mientras se disminuyen los efectos nocivos para el medio ambiente. Metodología: El análisis identificará los factores actuales que influencian la generación de llantas usadas, y lo ampliará con un pronóstico de la generación de llantas usadas en los siguientes 5 años, cubriendo el periodo de tiempo desde el 2019 al 2023. Siguiente a la predicción, se destacarán los métodos existentes para el manejo de llantas usadas, junto con los efectos medioambientales que son causados por la disposición inadecuada de este tipo de desecho. Resultados: Se evidencia una relación positiva creciente en los datos históricos respecto a la relación de vehículos registrados y el año. De la misma forma, la encuesta muestra que la mayor concentración de la muestra desecha las llantas usadas en basureros. Conclusión: De acuerdo con los resultados del pronóstico y las encuestas, se resalta la importancia de controlar la disposición de llantas usadas, por ello se establece que la mejor práctica para reducir o eliminar las llantas usadas es el coprocesamiento para hornos cementeros y trituración mecánica por su factor cero emisiones

    Optical sensor to determine plant spacing for precise application

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    Congreso Agroingeniería 2015. Orihuela (Alicante). 1 a 3 de junio de 2015La automatización en el manejo de la mala hierba de forma individualizada está siendo una realidad cada vez más cercana, tanto objetivos de eficiencia como de beneficio económico se están consiguiendo. En un futuro muy próximo la mecanización y su diseño tendrá que contemplar técnicas de monitorización o detección de precisión. El objetivo de este estudio fue evaluar la capacidad de un sensor óptico para determinar el espacio entre las plantas de una misma línea de cultivo en diferentes condiciones: laboratorio y campo. Este equipo de trabajo ha investigado la detección del cultivo con un sensor fotoeléctrico de infrarrojo (880 nm) en modo opuesto. La barrera fotoeléctrica de transmisión, usa un par de sensores y al paso de la planta por la cortina de luz interrumpe el haz. La señal de luz se recibe de forma simultánea en tiempo real mediante un sistema de control de alta velocidad. El sensor fotoeléctrico fue capaz de detectar la planta de tomate y por tanto de terminar la separación entre ellas de forma muy precisa. El uso de sistemas de detección como este puede dar lugar a una nueva era que permita el control en la línea de cultivo de la mala hierba de forma más económica y a la automatización de la operación. El control preciso de la mala hierba es un reto importante para este grupo, por ello tenemos previsto seguir trabajando en esta línea.Automation of individual crop plant care in commercial vegetable crop fields has increased practical feasibility and improved efficiency and economic benefit. Its systems approach is taken in the mechanization engineering design by the incorporation of precision sensing techniques. The objective of this study was design-sensing capabilities in an implement for measuring plant spacing under different test conditions: laboratory and field. For that proposal, a photoelectric transmission barrier, by using an optical light curtain transmitter and receiver, evaluated the interruption by the tomato stem of the light curtain, being recorded simultaneously in real-time by a high-speed embedded control system. The optical sensor provided tomato plant detection and therefore the spacing between tomato plants was determined with accuracy. The use of this detection system may result in a new era that allow for an online control of aggressive weeds and the automation of weeding tools, which we plan to pursue through future research.Junta de Andalucía P12-AGR-122

    Determination by optical systems of the inter-plant real distance for precise weed control

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    La automatización en el manejo de las malas hierbas de forma individualizada está siendo una realidad cada vez más cercana, atendiendo a objetivos tanto de eficiencia como de beneficios económicos. En un futuro muy próximo la mecanización y su diseño tendrá que contemplar técnicas de monitorización o detección de precisión. El objetivo de este estudio fue evaluar la capacidad de un sensor óptico para determinar la distancia entre las plantas de una misma línea de cultivo en condiciones de laboratorio y campo. En concreto, se ha investigado la detección de plantas con un sensor fotoeléctrico de infrarrojo (880 nm) en modo opuesto. El sensor fotoeléctrico fue capaz de detectar la planta de tomate y por tanto permitir conocer la separación entre ellas de forma muy precisa. El uso de sistemas de detección como este puede dar lugar a una nueva era que permita el control en la línea de cultivo de la mala hierba de forma más económica y a la automatización de la operación.Automation of individual crop plant care in comercial vegetable crop fields has increased practical feasibility and improved efficiency and economic benefit. Its systems approach is taken in the mechanization engineering design by the incorporation of precision sensing techniques. The objective of this study was design-sensing capabilities in an implement for measuring plant spacing under different test conditions: laboratory and field. The optical sensor provided tomato plant detection and therefore the spacing between tomato plants was determined with accuracy. The use of this detection system may result in a new era that allow for an online control of aggressive weeds and the automation of weeding tools, which we plan to pursue through future research

    A new Aphid genus and species (Hemiptera: Aphididae: Macrosiphini) living on ferns in Costa Rica and Mexico

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    P. 509-520Aphid species colonising ferns belong to the subfamily Aphidinae (Hemiptera: Aphididae) and the majority of these to the tribe Macrosiphini. A new genus in this tribe and its type species: Gibbomyzus pteridophytorum new genus, new species, are established. Apterous and alate viviparous females are described from specimens collected on Blechnum buchtienii Rosenstock (Blechnaceae) in Costa Rica and on Pteridium aquilinum (Linnaeus) Kuhn (Dennstaedtiaceae) and an unidentified fern in Mexico. The taxonomic validity of the two new taxa is discussed based on morphological and molecular data. Morphologically, the new genus is compared with genera with swollen siphunculi recorded in the New World, and also with genera living on ferns anywhere in the world. The identification key by Blackman and Eastop to aphids living on ferns is modified. Molecular analyses were carried out on the sequences of a fragment of the mitochondrial gene encoding for cytochrome c oxidase subunit 1 and of a fragment of the nuclear gene encoding elongation factor-1 alpha. In both analyses, G. pteridophytorum new species sequences showed considerable divergence (,4% or more) from those of 23 other species from diverse genera of Macrosiphini, supporting the conclusions of the morphological study and justifying the establishment of the new genusS

    Using machine learning methods to determine a typology of patients with HIV-HCV infection to be treated with antivirals

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    Several European countries have established criteria for prioritising initiation of treatment in patients infected with the hepatitis C virus (HCV) by grouping patients according to clinical characteristics. Based on neural network techniques, our objective was to identify those factors for HIV/HCV co-infected patients (to which clinicians have given careful consideration before treatment uptake) that have not being included among the prioritisation criteria. This study was based on the Spanish HERACLES cohort (NCT02511496) (April-September 2015, 2940 patients) and involved application of different neural network models with different basis functions (product-unit, sigmoid unit and radial basis function neural networks) for automatic classification of patients for treatment. An evolutionary algorithm was used to determine the architecture and estimate the coefficients of the model. This machine learning methodology found that radial basis neural networks provided a very simple model in terms of the number of patient characteristics to be considered by the classifier (in this case, six), returning a good overall classification accuracy of 0.767 and a minimum sensitivity (for the classification of the minority class, untreated patients) of 0.550. Finally, the area under the ROC curve was 0.802, which proved to be exceptional. The parsimony of the model makes it especially attractive, using just eight connections. The independent variable "recent PWID" is compulsory due to its importance. The simplicity of the model means that it is possible to analyse the relationship between patient characteristics and the probability of belonging to the treated group

    Developing New Tools to Determine Plant Spacing for Precise Agrochemical Application

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    CIGR - AgEng 2016 Aarhus, Denmark 26 - 29 JuneAdvances in the usage of computer imaging, communication technologies and the successful development of new techniques for precision agriculture have facilitated a smart-digital revolution in row crop agriculture in recent years. The use of a yield monitor, variable rate application (VRA) for fertilizer and herbicides, soil property maps and Global Navigation Satellite System (GNSS) technology has enabled the development of computer generated prescription maps for farm management. All these technologies are changing agricultural practices from simple mechanical operations to automated operations implemented by robotic-based systems. The automation of individual crop plant care in vegetable crop fields has increased its practical feasibility and improved efficiency and economic benefit. A systems-based approach is a key feature in the mechanization engineering design via the incorporation of precision sensing techniques. The objective of this study was to design sensing capabilities for implementation to measure plant spacing under different test conditions (California, USA and Andalucía, Spain). Three different optical sensors were used: an optical light curtain transmitter and receiver (880nm), a LiDAR sensor (905 nm), and an RGB camera. An active photoelectric transmission sensor, which contained 3 pairs of optical light curtain transmitters and receivers, evaluated the interruption by the tomato stem of the light curtain between the two devices, and was recorded simultaneously in real-time by a high-speed embedded control system. The LiDAR (model LMS 211 in California and LMS 111 in Spain, from SICK AG) was installed in a vertical orientation in the middle of the mobile platform. Additionally, a RGB spatial mosaicked image was used to adjust the data from the light beam and LiDAR sensor and obtain combined information (RGBD where D is for distance). These sensors were used to properly detect, localize, and discriminate between weed and tomato plants. The use of this detection system may result in a new technique that allows for the automatic control of aggressive weeds and the automation of weeding tools.Ministerio de Economía y Competitividad AGL2013-46343-RJunta de Andalucía P12-AGR-122
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