581 research outputs found

    Dispositivo y procedimiento útil para el control de un automóvil, con ayuda de GPS y comunicaciones inalámbricas, que permite efectuar adelantamientos

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    Dispositivo y procedimiento útil para el control de un automóvil, con ayuda de GPS y comunicaciones inalámbricas, que permite efectuar adelantamientos. El dispositivo y procedimiento permite el control automático para realizar mediante un computador maniobras de adelantamiento en carretera, manejando los tres actuadores principales del vehículo, acelerador, freno y dirección sin intervención humana, basándose en información sensorial proveniente de sistemas GNSS, redes de comunicaciones inalámbricas Wi.Fi y la información de navegación del propio vehículo. La computación de control del sistema esta basada en algoritmos de lógica borrosa desarrollados por los autores.Peer reviewedConsejo Superior de Investigaciones Científicas (España)A1 Solicitud de patentes con informe sobre el estado de la técnic

    Autonomous Vehicle Based in Cooperative GPS and Intertial Systems

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    A system including Global Positioning Systems (GPS) and digital cartography is a good solution to carry out vehicle's guidance. However, it has inconveniences like high sensibility to multipath and interference when the GPS signal is blocked by external agents. Another system is mandatory to avoid this error. This paper presents a cooperative system based on GPS and Inertial Navigation Systems (INS) for automated vehicle position. The control system includes a decision unit to choose which value is the correct. In case GPS is working at top precision, it takes the control. On the other part, GPS signal can be lost and inertial control system guides the car in this occasion. A third possibility is contemplated: we receive the signal from GPS but the accuracy is over one meter. Now, position value is obtained by means of both systems. Experimental results analyze two situations: guidance in an urban area where GPS signal can be occluded by buildings or trees during short time intervals and the possibility of loss of the signal in long time to simulate the circulation in tunnels. Good results have been observed in tests and it demonstrates how a cooperative system improves the automated vehicle guidance

    A Scoping Review on Virtual Reality-Based Industrial Training

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    The fourth industrial revolution has forced most companies to technologically evolve, applying new digital tools, so that their workers can have the necessary skills to face changing work environments. This article presents a scoping review of the literature on virtual reality-based training systems. The methodology consisted of four steps, which pose research questions, document search, paper selection, and data extraction. From a total of 350 peer-reviewed database articles, such as SpringerLink, IEEEXplore, MDPI, Scopus, and ACM, 44 were eventually chosen, mostly using the virtual reality haptic glasses and controls from Oculus Rift and HTC VIVE. It was concluded that, among the advantages of using this digital tool in the industry, is the commitment, speed, measurability, preservation of the integrity of the workers, customization, and cost reduction. Even though several research gaps were found, virtual reality is presented as a present and future alternative for the efficient training of human resources in the industrial field.This work was supported by Instituto Superior Tecnológico Victoria Vásconez Cuvi. The authors appreciate the opportunity to analyze topics related to this paper. The authors must also recognize the supported bringing by Universidad Tecnica de Ambato (UTA) and their Research and Development Department (DIDE) under project CONIN-P-256-2019, and SENESCYT by grants “Convocatoria Abierta 2011” and “Convocatoria Abierta 2013”

    Nonlinear absorption of InN/InGaN multiple-quantum-well structures at optical telecommunication wavelengths

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    We report on the nonlinear optical absorption of InN/ InxGa 1-x N (x=0.8,0.9) multiple-quantum-well structures characterized at 1.55 μm by the Z-scan method in order to obtain the effective nonlinear absorption coefficient (α2) of the samples at high repetition rate. Saturable absorption is observed for the sample with x=0.9, with an effective α2 ∼-9× 103 cm/GW for the studied optical regime. For lower In content in the barrier, reverse saturable absorption is observed, which is attributed to two-photon absorption. © 2011 American Institute of Physics.Peer Reviewe

    Design and Validation of an Augmented Reality System for Laparoscopic Surgery in a Real Environment

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    Purpose. This work presents the protocol carried out in the development and validation of an augmented reality system which was installed in an operating theatre to help surgeons with trocar placement during laparoscopic surgery. The purpose of this validation is to demonstrate the improvements that this system can provide to the field of medicine, particularly surgery. Method. Two experiments that were noninvasive for both the patient and the surgeon were designed. In one of these experiments the augmented reality system was used, the other one was the control experiment, and the system was not used. The type of operation selected for all cases was a cholecystectomy due to the low degree of complexity and complications before, during, and after the surgery. The technique used in the placement of trocars was the French technique, but the results can be extrapolated to any other technique and operation. Results and Conclusion. Four clinicians and ninety-six measurements obtained of twenty-four patients (randomly assigned in each experiment) were involved in these experiments.The final results show an improvement in accuracy and variability of 33% and 63%, respectively, in comparison to traditional methods, demonstrating that the use of an augmented reality system offers advantages for trocar placement in laparoscopic surgery.This work has been supported by Centro para el Desarrollo Tecnologico Industrial (CDTI) under the project Oncotic (IDI-20101153) and the Hospital Clinica Benidorm(HCB) and partially supported by the Ministry of Education and Science of Spain (TIN2010-20999-C04-01), the project Consolider-C (SEJ2006-14301/PSIC) and the "CIBER of Physiopathology of Obesity Nutrition, an initiative of ISCIII" Prometheus and Excellence Research Program (Generalitat Valenciana, Department of Education, 2008-157). The authors would like to express their gratitude to the Hospital Clinica Benidorm and to the Hospital Univeritari i Politecnic la Fe (especially the surgical team) for their participation and involvement in this work.López-Mir, F.; Naranjo Ornedo, V.; Fuertes Cebrián, JJ.; Alcañiz Raya, ML.; Bueno, J.; Pareja, E. (2013). Design and Validation of an Augmented Reality System for Laparoscopic Surgery in a Real Environment. BioMed Research International. 2013:1-12. https://doi.org/10.1155/2013/758491S1122013Rowe, C. K., Pierce, M. W., Tecci, K. C., Houck, C. S., Mandell, J., Retik, A. B., & Nguyen, H. T. (2012). A Comparative Direct Cost Analysis of Pediatric Urologic Robot-Assisted Laparoscopic Surgery Versus Open Surgery: Could Robot-Assisted Surgery Be Less Expensive? Journal of Endourology, 26(7), 871-877. doi:10.1089/end.2011.0584Azuma, R. T. (1997). A Survey of Augmented Reality. Presence: Teleoperators and Virtual Environments, 6(4), 355-385. doi:10.1162/pres.1997.6.4.355Shuhaiber, J. H. (2004). Augmented Reality in Surgery. Archives of Surgery, 139(2), 170. doi:10.1001/archsurg.139.2.170Kersten-Oertel, M., Jannin, P., & Collins, D. L. (2012). DVV: A Taxonomy for Mixed Reality Visualization in Image Guided Surgery. IEEE Transactions on Visualization and Computer Graphics, 18(2), 332-352. doi:10.1109/tvcg.2011.50Cannon, J. W., Stoll, J. A., Selha, S. D., Dupont, P. E., Howe, R. D., & Torchiana, D. F. (2003). Port placement planning in robot-assisted coronary artery bypass. IEEE Transactions on Robotics and Automation, 19(5), 912-917. doi:10.1109/tra.2003.817502Adhami, L., & Coste-Manirei, E. (2003). Optimal planning for minimally invasive surgical robots. IEEE Transactions on Robotics and Automation, 19(5), 854-863. doi:10.1109/tra.2003.817061Bichlmeier, C., Heining, S. M., Feuerstein, M., & Navab, N. (2009). The Virtual Mirror: A New Interaction Paradigm for Augmented Reality Environments. IEEE Transactions on Medical Imaging, 28(9), 1498-1510. doi:10.1109/tmi.2009.2018622Feuerstein, M., Mussack, T., Heining, S. M., & Navab, N. (2008). Intraoperative Laparoscope Augmentation for Port Placement and Resection Planning in Minimally Invasive Liver Resection. IEEE Transactions on Medical Imaging, 27(3), 355-369. doi:10.1109/tmi.2007.907327Abdominal and Laparoscopic Surgery. (2010). International Journal of Computer Assisted Radiology and Surgery, 5(S1), 122-130. doi:10.1007/s11548-010-0446-3Ferrari, V., Megali, G., Troia, E., Pietrabissa, A., & Mosca, F. (2009). A 3-D Mixed-Reality System for Stereoscopic Visualization of Medical Dataset. IEEE Transactions on Biomedical Engineering, 56(11), 2627-2633. doi:10.1109/tbme.2009.2028013McSherry, C. K. (1989). Cholecystectomy: The gold standard. The American Journal of Surgery, 158(3), 174-178. doi:10.1016/0002-9610(89)90246-8Kum, C.-K., Eypasch, E., Aljaziri, A., & Troidl, H. (1996). Randomized comparison of pulmonary function after the ‘French’ and ‘American’ techniques of laparoscopic cholecystectomy. British Journal of Surgery, 83(7), 938-941. doi:10.1002/bjs.1800830716Mischkowski, R. A., Zinser, M. J., Kübler, A. C., Krug, B., Seifert, U., & Zöller, J. E. (2006). Application of an augmented reality tool for maxillary positioning in orthognathic surgery – A feasibility study. Journal of Cranio-Maxillofacial Surgery, 34(8), 478-483. doi:10.1016/j.jcms.2006.07.862Kawamata, T., Iseki, H., Shibasaki, T., & Hori, T. (2002). Endoscopic Augmented Reality Navigation System for Endonasal Transsphenoidal Surgery to Treat Pituitary Tumors: Technical Note. Neurosurgery, 50(6), 1393-1397. doi:10.1097/00006123-200206000-00038Vogt, S., Khamene, A., & Sauer, F. (2006). Reality Augmentation for Medical Procedures: System Architecture, Single Camera Marker Tracking, and System Evaluation. International Journal of Computer Vision, 70(2), 179-190. doi:10.1007/s11263-006-7938-1Nicolau, S., Soler, L., Mutter, D., & Marescaux, J. (2011). Augmented reality in laparoscopic surgical oncology. Surgical Oncology, 20(3), 189-201. doi:10.1016/j.suronc.2011.07.002Zhang, Z. (2000). A flexible new technique for camera calibration. IEEE Transactions on Pattern Analysis and Machine Intelligence, 22(11), 1330-1334. doi:10.1109/34.888718Martín-Gutiérrez, J., Luís Saorín, J., Contero, M., Alcañiz, M., Pérez-López, D. C., & Ortega, M. (2010). Design and validation of an augmented book for spatial abilities development in engineering students. Computers & Graphics, 34(1), 77-91. doi:10.1016/j.cag.2009.11.003Marquardt, D. W. (1963). An Algorithm for Least-Squares Estimation of Nonlinear Parameters. Journal of the Society for Industrial and Applied Mathematics, 11(2), 431-441. doi:10.1137/011103

    Sediment characterization of an artificial reservoir impacted by mining activity in the Almadén mercury district (Spain)

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    Los sedimentos del embalse Castilseras, ubicado aguas abajo en el río Valdeazogues en el distrito de Almadén, se recogieron para evaluar los contenidos en mercurio totales asociados con las aportaciones de sedimentos del río que provienen de las minas clausuradas. Se ha determinado el contenido en mercurio total así como otras propiedades físico-químicas de estos sedimentos. Los resultados muestran que el contenido en mercurio es elevado, y que se relaciona con el de los materiales de la zona, relacionados con la minería. Los sedimentos presentan un nivel de acidez significativo, son moderadamente salinos y tienen un tamaño de grano predominantemente limoso. El análisis estadístico indica que las concentraciones de mercurio están positivamente correlacionadas con el porcentaje en limo de las muestras. De los resultados obtenidos se puede concluir que el contenido en mercurio se va diluyendo aguas abajo del embalse y que éste está relacionado con la actividad minera, convirtiendo a Castilseras en uno de los embalses con mayor contenido en mercurio del mundo.Sediments from the Castilseras reservoir, located downstream of the Valdeazogues River in the Almadén mercury district were collected to assess the total mercury content associated with river sediment input from several decommissioned mines. A geochemical characterization, including the determination of total mercury content, were investigated using different physical and chemical techniques. The results obtained suggested that sediments are slightly acidic and characterized by high mercury, related to mining activities. In addition, sediments showed a silty texture and the electrical conductivity results showed moderate salinity, related to acid mine drainage (AMD) processes. The multivariate statistical analysis suggested that mercury content is positively correlated with the silt fraction in collected samples. In regard to the obtained results, we can conclude that Castilseras is one of the reservoirs with the highest mercury concentration, as a result of mining activities carried out in the zone. In this reservoir, the mercury content is diluted downstreamDepto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

    A Scoping Review on Virtual Reality-Based Industrial Training

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    The fourth industrial revolution has forced most companies to technologically evolve, applying new digital tools, so that their workers can have the necessary skills to face changing work environments. This article presents a scoping review of the literature on virtual reality-based training systems. The methodology consisted of four steps, which pose research questions, document search, paper selection, and data extraction. From a total of 350 peer-reviewed database articles, such as SpringerLink, IEEEXplore, MDPI, Scopus, and ACM, 44 were eventually chosen, mostly using the virtual reality haptic glasses and controls from Oculus Rift and HTC VIVE. It was concluded that, among the advantages of using this digital tool in the industry, is the commitment, speed, measurability, preservation of the integrity of the workers, customization, and cost reduction. Even though several research gaps were found, virtual reality is presented as a present and future alternative for the efficient training of human resources in the industrial field.Facultad de Informátic

    Fatal gemcitabine-induced pulmonary toxicity in metastatic gallbladder adenocarcinoma

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    Gemcitabine is a chemotherapy agent that may cause unpredictable side effects. In this report, we describe a fatal gemcitabine-induced pulmonary toxicity in a patient with gallbladder metastatic adenocarcinoma. A 72-year-old patient was submitted to an elective laparoscopic cholecystectomy, and a tubular adenocarcinoma in the gallbladder was incidentally diagnosed. CT scan and ultrasound before the surgery did not show any tumor. After the surgery a Pet scan was positive for a hot-spot in the left colon. The colonic lesion was conveniently removed and the histology evaluation confirmed the diagnosis of adenocarcinoma tubular. The patient was then submitted to three sections of 1,600 mg/m2 of gemcitabine with intervals of 1 week. Three weeks later he developed severe respiratory distress. A helicoidal CT scan showed diffuse and severe interstitial pneumonitis, and lung biopsy confirmed accelerated usual interstitial pneumonia consistent with drug-induced toxicity. The patient presented unfavorable evolution with progressive worsening of respiratory function, hypotension, and renal failure. He died 1 month later in spite of methylprednisolone pulse therapy, large spectrum antimicrobial therapy, and full support of respiratory, hemodynamic and renal systems. Gemcitabine-induced pulmonary toxicity is usually a dramatic condition. Physicians should suspect pulmonary toxicity in patients with respiratory distress after gemcitabine chemotherapy, mainly in elderly patients

    STUDIA: una aplicación para apoyar el conteo de carbohidratos simulando la dinámica de la glucosa

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    Contexto: El conteo de carbohidratos se ha considerado la forma ideal de calcular la insulina prandial, por ende se han propuesto varias formas de mejorarlo. Objetivo: Proponemos refinar el conteo de carbohidratos utilizando una simulación, la cual se presenta en una aplicación móvil, STUDIA, que simula en tiempo real la glucosa postprandial. Métodos: Utilizamos un fenomenológico del tracto gastrointestinal, acoplado al modelo mínimo para la glucosa postprandial en personas con diabetes mellitus tipo 1 (DM1). Las funciones y requisitos técnicos se definieron mediante un sistema de adquisición de requerimientos. Para la caracterización de usuarios, utilizamos una aproximación basada en el individuo. El ecosistema de datos se evaluó mediante el criterio UX/UI, la curva de aprendizaje, flexibilidad y la posibilidad de ejecutar modelos matemáticos. Utilizamos datos de un paciente con DM1 para ejemplificar el uso de la aplicación y los datos del monitoreo continuo de glucosa para comparación. Resultados: STUDIA fue construida en Android Studio® con una interfaz de usuario y un módulo administrativo basado en la web conectado a AWS®. Permite similar la glucosa basado en el conteo de carbohidratos para su refinamiento. Se utilizan los parámetros del paciente y los datos históricos de la glucosa para el ajuste de la aplicación. Esta aplicación puede ser utilizada tanto por los pacientes para comparar diferentes escenarios al igual que en la investigación clínica. Conclusiones: Presentamos la primera aplicación para simular la glucosa postprandial basada en un modelo fenomenológico del tracto gastrointestinal para pacientes con DM1. STUDIA se probará con datos históricos de pacientes y en un ensayo clínico
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