31 research outputs found

    Editorial

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    Estimado lector, Nos complace informar que la Revista Politécnica ha sido Pre‐ aprobada para ingresar al sistema de información científica Redalyc (Red de Revistas Científicas de América Latina y el Caribe, España y Portugal) que proporciona Acceso abierto a la producción científica publicada en revistas iberoamericanas

    Aproximación al control de la fase de vuelo de un dirigible

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    The aims of this work are the development of a dynamic model for an airship (like Karma and UrAn airships), and the elaboration of a set of base control laws of speed, altitude and heading in cruise flight. The first part of the document presents a mathematical model of the blimp dynamics. The analytic description of the model has been deduced from a dynamic and aerodynamic study. In a first time, the model parameters have been taken from precedent works based on wind tunnel experiments. Next to that, simplified models (called control model) were made with classical techniques. A second part is devoted to the formulation of control strategies (like PID, GPC and Non-lineal), based on the decoupling of the velocity, the longitudinal and lateral dynamics. These different control strategies have been validated by numerous simulation tests. The speed, heading and altitude controllers have been tested in two real airship structures.El presente trabajo tiene por objetivo el modelo dinámico de un dirigible (como Karma y UrAn), y la elaboración de un conjunto de leyes de control de velocidad, altitud y dirección cuando el dirigible se desplaza en la fase de vuelo crucero. La primera parte del documento presenta un modelo matemático representativo de las principales dinámicas del dirigible. Luego se muestra una descripción de las principales relaciones de las variables, a partir de un modelado e identificación previos, usados para el planteamiento de modelos reducidos, llamados modelos de control. Una segunda parte está dedicada a la formulación de las estrategias de control, basadas en técnicas PID, GPC y una no Lineal. Estas leyes son planteadas sobre la base del desacople de dinámicas para el vuelo lateral y el vuelo longitudinal. Finalmente se incluyen pruebas de simulación y sobre las estructuras reales

    Vehículos de guiado autónomo (AGV) en aplicaciones industriales: una revisión

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    A review of the state of the art is presented of the autonomous guidance vehicles (AGV) to transport objects and raw material in industrial applications. The literature review is focus in different topics as the identification of place, application in different environments, vehicle control and description of the software systems used for the programming of mobile robots, according to the requirements or needs to be resolved. Additionally, an analysis is made, based on the aforementioned references, of the contribution made by this type of technologies not only to the industry, but also to other types of business model, such as the health area, the systems of urban transport, etc.Se presenta una revisión del estado del arte de vehículos de guiado autónomo (AGV por sus siglas en inglés: Automated Guided Vehicle) para el transporte de objetos y materia prima en aplicaciones industriales. La revisión de literatura hace énfasis en varios aspectos como la identificación del lugar, aplicación en diferentes entornos, control del vehículo y descripción de los sistemas de software usados para la programación de los robots móviles, de acuerdo a los requisitos o necesidades a resolver. Adicionalmente, se hace un análisis, con base a las referencias citadas, del aporte que hace este tipo de tecnologías no solo a la industria, sino también a otros tipos de modelo de negocio, como lo son el área de la salud, los sistemas de transporte urbano, entre otros. Se presenta una revisión del estado del arte de vehículos de guiado autónomo (AGV por sus siglas en inglés: Automated Guided Vehicle) para el transporte de objetos y materia prima en aplicaciones industriales. La revisión de literatura hace énfasis en varios aspectos como la identificación del lugar, aplicación en diferentes entornos, control del vehículo y descripción de los sistemas de software usados para la programación de los robots móviles, de acuerdo a los requisitos o necesidades a resolver. Adicionalmente, se hace un análisis, con base a las referencias citadas, del aporte que hace este tipo de tecnologías no solo a la industria, sino también a otros tipos de modelo de negocio, como lo son el área de la salud, los sistemas de transporte urbano, entre otros.  A review of the state of the art is presented of the autonomous guidance vehicles (AGV) to transport objects and raw material in industrial applications. The literature review is focus in different topics as the identification of place, application in different environments, vehicle control and description of the software systems used for the programming of mobile robots, according to the requirements or needs to be resolved. Additionally, an analysis is made, based on the aforementioned references, of the contribution made by this type of technologies not only to the industry, but also to other types of business model, such as the health area, the systems of urban transport, etc.

    Planificación de trayectorias para un robot tipo con restricciones dinámicas

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    In this article we propose a method to find the optimal trajectories of a robot with dynamic constrains. The system acts in a free space and in horizontal plane (2D). A dynamic model description for the airship movement on the 2D plane is presented. This model is used in order to make the kinematic model formulation. The optimal control theory is used to find the optimal trajectory for a kind of robot subject to kinematic constraints on its path curvature and its orientation. Two modified models are considerate and with they, better-adapted trajectories to the dynamic constrains are planned. Comparisons and conclusions based over simulations are presented at the end.Este documento presenta una aproximación a la planificación de caminos óptimos para un sistema con restricciones dinámicas y desplazándose dentro de un espacio libre de obstáculos. Se considera el modelo dinámico del dirigible y un análisis para el planteamiento de modelos simplificados o comúnmente conocidos como modelos de control. Se propone una planificación de la trayectoria desde el punto de vista de la teoría óptima utilizando un modelo de la dinámica de un robot móvil (que se desplaza a velocidad constante y en avance, es decir con restricciones dinámicas) como punto de partida para la primera aproximación a los caminos óptimos. Para el suavizado de las trayectorias del dirigible se proponen dos modelos con relajación en la dinámica de la variable de control y finalmente se presenta una simulación de la comparación de los diferentes resultados

    Inter-acciones: apuestas regionales de la investigación en comunicación

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    Transformación social, desarrollo y gestión de la comunicación en investigación; Educación y comunicación en procesos de transformación cultural; y Medios, convergencia y cibercultura. Además, responde a la pregunta: ¿qué líneas aborda la investigación en Comunicación Social desde la modalidad virtual y a distancia de UNIMINUTO? Lo anterior, con el objetivo de acoplar la investigación básica y aplicada desde el nivel de pregrado, en atención a los retos que afronta la formación del nuevo comunicador social con respecto al componente de investigación e innovación desde los semilleros de investigación; además, en consideración a que los semilleros son un espacio institucional para el fomento de la cultura investigativa institucional y de programas, propiciar la interacción entre la comunidad académica con miras al fortalecimiento de la excelencia académica, el desarrollo social y el progreso científico de la comunidad, así como la generación de la capacidad de trabajo en grupo, la interdisciplinariedad y el establecimiento de redes de investigación

    Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease

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    We identified rare coding variants associated with Alzheimer’s disease (AD) in a 3-stage case-control study of 85,133 subjects. In stage 1, 34,174 samples were genotyped using a whole-exome microarray. In stage 2, we tested associated variants (P<1×10-4) in 35,962 independent samples using de novo genotyping and imputed genotypes. In stage 3, an additional 14,997 samples were used to test the most significant stage 2 associations (P<5×10-8) using imputed genotypes. We observed 3 novel genome-wide significant (GWS) AD associated non-synonymous variants; a protective variant in PLCG2 (rs72824905/p.P522R, P=5.38×10-10, OR=0.68, MAFcases=0.0059, MAFcontrols=0.0093), a risk variant in ABI3 (rs616338/p.S209F, P=4.56×10-10, OR=1.43, MAFcases=0.011, MAFcontrols=0.008), and a novel GWS variant in TREM2 (rs143332484/p.R62H, P=1.55×10-14, OR=1.67, MAFcases=0.0143, MAFcontrols=0.0089), a known AD susceptibility gene. These protein-coding changes are in genes highly expressed in microglia and highlight an immune-related protein-protein interaction network enriched for previously identified AD risk genes. These genetic findings provide additional evidence that the microglia-mediated innate immune response contributes directly to AD development

    Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

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    BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to &lt;90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], &gt;300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of &lt;15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P&lt;0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P&lt;0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

    Impact of common cardio-metabolic risk factors on fatal and non-fatal cardiovascular disease in Latin America and the Caribbean: an individual-level pooled analysis of 31 cohort studies

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    Background: Estimates of the burden of cardio-metabolic risk factors in Latin America and the Caribbean (LAC) rely on relative risks (RRs) from non-LAC countries. Whether these RRs apply to LAC remains un- known. Methods: We pooled LAC cohorts. We estimated RRs per unit of exposure to body mass index (BMI), systolic blood pressure (SBP), fasting plasma glucose (FPG), total cholesterol (TC) and non-HDL cholesterol on fatal (31 cohorts, n = 168,287) and non-fatal (13 cohorts, n = 27,554) cardiovascular diseases, adjusting for regression dilution bias. We used these RRs and national data on mean risk factor levels to estimate the number of cardiovascular deaths attributable to non-optimal levels of each risk factor. Results: Our RRs for SBP, FPG and TC were like those observed in cohorts conducted in high-income countries; however, for BMI, our RRs were consistently smaller in people below 75 years of age. Across risk factors, we observed smaller RRs among older ages. Non-optimal SBP was responsible for the largest number of attributable cardiovascular deaths ranging from 38 per 10 0,0 0 0 women and 54 men in Peru, to 261 (Dominica, women) and 282 (Guyana, men). For non-HDL cholesterol, the lowest attributable rate was for women in Peru (21) and men in Guatemala (25), and the largest in men (158) and women (142) from Guyana. Interpretation: RRs for BMI from studies conducted in high-income countries may overestimate disease burden metrics in LAC; conversely, RRs for SBP, FPG and TC from LAC cohorts are similar to those esti- mated from cohorts in high-income countries

    Editorial

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    Aproximación al control de la fase de vuelo de un dirigible

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    The aims of this work are the development of a dynamic model for an airship (like Karma and UrAn airships), and the elaboration of a set of base control laws of speed, altitude and heading in cruise flight. The first part of the document presents a mathematical model of the blimp dynamics. The analytic description of the model has been deduced from a dynamic and aerodynamic study. In a first time, the model parameters have been taken from precedent works based on wind tunnel experiments. Next to that, simplified models (called control model) were made with classical techniques. A second part is devoted to the formulation of control strategies (like PID, GPC and Non-lineal), based on the decoupling of the velocity, the longitudinal and lateral dynamics. These different control strategies have been validated by numerous simulation tests. The speed, heading and altitude controllers have been tested in two real airship structures.El presente trabajo tiene por objetivo el modelo dinámico de un dirigible (como Karma y UrAn), y la elaboración de un conjunto de leyes de control de velocidad, altitud y dirección cuando el dirigible se desplaza en la fase de vuelo crucero. La primera parte del documento presenta un modelo matemático representativo de las principales dinámicas del dirigible. Luego se muestra una descripción de las principales relaciones de las variables, a partir de un modelado e identificación previos, usados para el planteamiento de modelos reducidos, llamados modelos de control. Una segunda parte está dedicada a la formulación de las estrategias de control, basadas en técnicas PID, GPC y una no Lineal. Estas leyes son planteadas sobre la base del desacople de dinámicas para el vuelo lateral y el vuelo longitudinal. Finalmente se incluyen pruebas de simulación y sobre las estructuras reales
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