13 research outputs found

    Fetal Movement Counting Improved Identification of Fetal Growth Restriction and Perinatal Outcomes – a Multi-Centre, Randomized, Controlled Trial

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    Background Fetal movement counting is a method used by the mother to quantify her baby's movements, and may prevent adverse pregnancy outcome by a timely evaluation of fetal health when the woman reports decreased fetal movements. We aimed to assess effects of fetal movement counting on identification of fetal pathology and pregnancy outcome. Methodology In a multicentre, randomized, controlled trial, 1076 pregnant women with singleton pregnancies from an unselected population were assigned to either perform fetal movement counting from gestational week 28, or to receive standard antenatal care not including fetal movement counting (controls). Women were recruited from nine Norwegian hospitals during September 2007 through November 2009. Main outcome was a compound measure of fetal pathology and adverse pregnancy outcomes. Analysis was performed by intention-to-treat. Principal Findings The frequency of the main outcome was equal in the groups; 63 of 433 (11.6%) in the intervention group, versus 53 of 532 (10.7%) in the control group [RR: 1.1 95% CI 0.7–1.5)]. The growth-restricted fetuses were more often identified prior to birth in the intervention group than in the control group; 20 of 23 fetuses (87.0%) versus 12 of 20 fetuses (60.0%), respectively, [RR: 1.5 (95% CI 1.0–2.1)]. In the intervention group two babies (0.4%) had Apgar scores <4 at 1 minute, versus 12 (2.3%) in the control group [RR: 0.2 (95% CI 0.04–0.7)]. The frequency of consultations for decreased fetal movement was 71 (13.1%) and 57 (10.7%) in the intervention and control groups, respectively [RR: 1.2 (95% CI 0.9–1.7)]. The frequency of interventions was similar in the groups. Conclusions Maternal ability to detect clinically important changes in fetal activity seemed to be improved by fetal movement counting; there was an increased identification of fetal growth restriction and improved perinatal outcome, without inducing more consultations or obstetric intervention

    A real time rescheduling algorithm based in Lyapunov stability's index for metro lines

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    [EN] A new Lyapunov-based index for designing a rescheduling algorithm in real time for metro lines has been proposed in this paper. A modified real time discrete space state model which considers saturation effects in the metro line has been utilized in this study. Once the space state model has been obtained, the direct method of Lyapunov is applied in order to analyze the stability of the metro line system. As a result of this analysis not only a new stability index is proposed, but also the establishment of three stability zones to indicate the current state of the system. Finally, a new algorithm which allows the rescheduling of the timetable in the real time of the trains under presence of medium disturbances has been presented.[ES] En este trabajo, se propone un nuevo índice basado en el método directo de Lyapunov para el diseño de un algoritmo de reprogramación en tiempo real para líneas de metro. En este estudio se utiliza una versión modificada de un modelo de espacio de estados en tiempo real discreto, que considera los efectos de saturación en la línea de metro. Una vez que el modelo de espacio de estados se ha obtenido, el método directo de Lyapunov se aplica con el fin de analizar la estabilidad del sistema de la línea de metro. Como resultado de este análisis no sólo se propone un nuevo índice de estabilidad, sino también la creación de tres zonas de estabilidad para indicar el estado actual del sistema. Finalmente, se presenta un nuevo algoritmo que permite la reprogramación del calendario de los trenes en tiempo real en presencia de perturbaciones medianas.Los autores de este trabajo quieren expresar su gratitud a la Secretaria Nacional de Ciencia, Tecnología e Innovación (SENACYT) del Gobierno de la República de Panamá por apoyar este proyecto de I+D a través de los fondos del Proyecto I+D “Metodologías e índices de desempeño para sistemas de transporte ferroviario” adjudicado a través de la convocatoria para actividades de I+D (MDEPR09-001) 2009-2011. Adicionalmente, los autores quieren agradecer el apoyo de la Universidad Tecnológica de Panamá, del grupo de Control Inteligente del DISAM y del Centro de Investigación en Tecnologías ferroviarias, ambos de la Universidad Politécnica de Madrid.Berbey, A.; Galán, R.; San Segundo, P.; Sanz Bobi, J.; Caballero, R. (2014). Un algoritmo de replanificación en tiempo real basado en un índice de estabilidad de Lyapunov para líneas de metro. Revista Iberoamericana de Automática e Informática industrial. 11(2):167-178. https://doi.org/10.1016/j.riai.2014.03.005OJS167178112Araya, S. and Sone, S. “Traffic Dynamics of Automated Transit Systems with Pre-established Schedules”. IEEE Transactions on Systems, Man and Cybernetics, Vol. SMC-14, No.4,July/August 1984.Assis, W.O; Milani, B.E.A. “Generation of optimal schedules for metro lines using model predictive control” Automatica 40(2004) 1397-1404.2004.Berbey, A., Galán, R., San Segundo, R. y Sanz-Bobi, J.D. “Análisis de estabilidad de Lyapunov aplicado a líneas de metro”. XXIX Jornadas de Automática, Tarragona. España. 3-5 September 2008a.Berbey, A., Galán, R., San Segundo, P. and Sanz-Bobi, J.D. “Lyapunov based stability analysis for metro lines” URBAN TRANSPORT 2008. Urban Transport 2008 XIV. Urban Transport and the environment in the 21st Century. Malta, 1-2 September 2008b. ISBN:978-1-84564-123-8.Berbey, A, Planificación en tiempo real de tráfico ferroviario. Tesis doctoral. Escuela Técnica Superior de Ingenieros Industriales. Universidad Politécnica de Madrid. 2008.Bergmann, D.R. Generalized expression for the minimun time interval between consecuctive arrivals at an idealized railway station. Transpn Res. Vol 6, pp.327-341.Pergamon Press 1972.Burden, R.L. y Douglas Faires, J. “Análisis numérico” Séptima Edición. 2002.Campion, G., Van Breusegem, V., Pinson, P. and Bastin, G. “Traffic Regulation of an underground railway transportation system by state feedback.” Optimal control Applications & Methods, Vol. 6, 385-402. 1985.Cury, J.E. Gomide, F.A.C. and Mendes, M.J. “A methodology for Generation of Optimal Schedules for an Underground Railway Systems” IEEE Transactions on automatic control, Vol. Ac-25, No.2, April 1980.F. de Cuadra, Fernández, A. and Granados, J.C. “Train simulation and headway calculations an approach based on parameterized continuous curves.” Instituto de Investigación Tecnológica (IIT-UPCO) 1994. DIMETRONICS S.A. Madrid, España. Computers in Railways IV-Volume 1: Railway Design and Management. Computational Mechanics PublicationsFernández, A., de Cuadra, F. y Montes, F. “Traffic regulation and simulation- a predictive adaptive control system.” Instituto de Investigación Tecnológica (IIT-UPCO) 1994. DIMETRONICS S.A. Madrid, España. Computers in Railways IV-Volume 1: Railway Design and Management. Computational Mechanics Publications.FFII. Fundación para el fomento de la innovación industrial. F2I2. “Herramienta de planificación off-line (HEPO)”. Proyecto I+D Sistema Automático de regulación y explotación ferroviaria. SAREF. Fundación para el Fomento de la Innovación Industrial. Madrid. Noviembre, 2006.Goodwin, Graham C., Sin, Kwai Sang (1984): “Adaptive filtering prediction and control.” Prentice-Hall information and system sciences series. Thomas Kailath, Series Editor. 1984.Nie, L. Hansen 05. Nie, Lei and Hansen, Ingo. System analysis of train operations and track occupancy at railway stations. EJTIR, 5, N°1(2005), pp.31-54.2005.Rice, P. “Urban transport systems capacity with special references to London Transport underground railways” Conf. on Control Aspects of New Forms of Guided Land Transport, London, August 1974.Sasama, H. and Ohkawa, Y. “Floating traffic control for public transportation systems” Proc. 4th IFAC Conf. on Contr. and Transport Syst., Baden- Baden, April 1983.Van Breusegem, V., Campion, G. and Bastin, G. “Traffic Modeling and State Feedback Control for Metro Lines.” IEEE Transactions on automatic control, Vol. 36, No.7, July, 1991
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