50 research outputs found

    A COMPARISON BETWEEN AN ORIGIN BASED METHOD AND A NONLINEAR COMPLEMENTARITY BASED METHOD FOR SOLVING THE TRAFFIC ASSIGNMENT PROBLEM

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    This thesis compares Bar-Gera's Method and Aashtiani's Method for solving the static traffic assignment problem with fixed demand. Specifically, it compares the computational time spent by their corresponding algorithms in thirteen networks based on real cities. It also verifies whether the assumptions made by both methods and the data used allowed such a comparison. To implement Aashtiani's algorithm, a computer code was appropriately designed. To implement Bar-Gera's algorithm, a non-open source application was used. Numerical results showed mixed results but still showed the following trends: (1) Aashtiani's algorithm seems to be faster when solving complex networks, (2) Bar-Gera's algorithm is almost always faster for very high levels of accuracy while Aashtiani's algorithm is faster for lower levels of accuracy, and (3) Bar-Gera's algorithm almost always increases its speed consistently as more accuracy is demanded. Numerical results also showed that for small networks (specifically, when the number of arcs times the number of links is less than 1.0E+7), both algorithms spent practically no more than one second, rending these networks not recommendable for carrying out future comparisons. As expected, Bar-Gera's method required less memory. This thesis also presents a unified terminology for both methods and adapted Aashtiani's formulation to this specific problem

    Pertinencia jur铆dica del convenio Interadministrativo No. 16 de 2009 celebrado entre el municipio de Carmen de Chucur铆 y la empresa de acueducto, alcantarillado y aseo 鈥揂CUASAN

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    Este trabajo de investigaci贸n busca analizar la pertinencia del convenio interadministrativo No 16 del 13 de noviembre de 2009 celebrado entre el municipio de Carmen de Chucuri y la empresa de acueducto, alcantarillado y aseo 鈥揂CUASAN-: un an谩lisis jur铆dico-constitucional a partir de las reglas de la contrataci贸n directa y de los principios de econom铆a, transparencia y el deber de selecci贸n objetiva. Para ello, se precisar谩 el marco legal, jurisprudencial y te贸rico de la contrataci贸n directa, enfatizando en la modalidad de Convenio Interadministrativo. A partir de lo anterior, se describir谩 el marco normativo, jurisprudencial y te贸rico de los principios de la contrataci贸n estatal, de econom铆a, transparencia y deber de selecci贸n objetiva. Por 煤ltimo, se har谩 un parang贸n entre el sentido de los principios mencionados y el referido convenio interadministrativo, esto en aras de determinar su congruencia, concordancia y pertinencia jur铆dico-constitucional.Universidad Libre Seccional Socorro -- Facultad de derecho, ciencias pol铆ticas y sociales -- Maestr铆a en derecho administrativoThis research work seeks to establish the relevance of inter-administrative agreement No. 16 of November 13, 2009, between the municipality of Carmen de Chucuri and the aqueduct, sewage and sanitation company -ACUASAN-: a legal-constitutional analysis based on the rules of direct contracting and the principles of economy and transparency and the duty of objective selection. For this, the legal, jurisprudential and theoretical framework of direct contracting will be specified, emphasizing the Inter-administrative Agreement modality. Based on the above, the regulatory, jurisprudential and theoretical framework of the principles of state contracting of economy, transparency and duty of objective selection will be described. Finally, a comparison will be made between the meaning of the principles of state contracting and the aforementioned inter-administrative agreement, in order to determine its consistency, concordance and legal-constitutional relevance

    Efecto de la radiaci贸n ultravioleta B sobre mohos pat贸genos de setas cultivadas

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    Es conocido el efecto fungicida de la radiaci贸n UV-C (100-280nm de longitud de onda), pero suaplicabilidad para el control de mohos pat贸genos de setas cultivadas resulta condicionada porsu efecto sobre el hu茅sped y por los riesgos inherentes a su manipulaci贸n. Como alternativa, seha estudiado el efecto de la radiaci贸n UV-B (280-315nm) sobre los principales mohos pat贸genosde los cultivos de setas causantes de lesiones conocidas como telara帽a o pelo (Cladobotryummycophilum), mole seca (Lecanicillium fungicola), moho verde (Trichoderma aggressivum) ymole h煤meda (Mycogone perniciosa). Los mohos estudiados se sembraron (por triplicado) sobreplacas de agar Czapek que se irradiaron con l谩mparas de radiaci贸n UV-B (300nm) situadas a 25cmde altura, obteniendo una irradiancia de 16 Wm-2. Se aplicaron diferentes tiempos de exposici贸n(0, 1, 3, 6, 12 y 24 horas) sobre dos series de placas. Una de las series se protegi贸 de la radiaci贸nmediante filtros de radiaci贸n UV y actu贸 de control. Tras la exposici贸n, las placas fueron incubadasa 20潞C en oscuridad, valorando el grado de desarrollo de los mohos a lo largo de dos semanas. Laradiaci贸n UV-B caus贸 un claro efecto inhibidor, proporcional a la dosis de irradiaci贸n recibida, enel desarrollo de los mohos estudiados. Aunque en ning煤n caso se observ贸 la muerte del moho, elretraso en el crecimiento respecto a su control lleg贸 a alcanzar los 8-12 d铆as seg煤n especie. Paracomprobar si la radiaci贸n aplicada afectaba al desarrollo de la seta cultivada, se inocularon placasde Agar Compost con Agaricus bisporus y se expusieron a radiaci贸n UV-B (0, 6, 12 y 24 h). No seobservaron diferencias entre el desarrollo de champi帽贸n en las placas irradiadas y su control. Esteresultado permitir铆a utilizar la radiaci贸n UV-B en el control de mohos micopat贸genos sin afectar alas setas cultivadas

    Oral insulin-mimetic compounds that act independently of insulin

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    The hallmarks of insulin action are the stimulation and suppression of anabolic and catabolic responses, respectively. These responses are orchestrated by the insulin pathway and are initiated by the binding of insulin to the insulin receptor, which leads to activation of the receptor's intrinsic tyrosine kinase. Severe defects in the insulin pathway, such as in types A and B and advanced type 1 and 2 diabetes lead to severe insulin resistance, resulting in a partial or complete absence of response to exogenous insulin and other known classes of antidiabetes therapies. We have characterized a novel class of arylalkylamine vanadium salts that exert potent insulin-mimetic effects downstream of the insulin receptor in adipocytes. These compounds trigger insulin signaling, which is characterized by rapid activation of insulin receptor substrate-1, Akt, and glycogen synthase kinase-3 independent of insulin receptor phosphorylation. Administration of these compounds to animal models of diabetes lowered glycemia and normalized the plasma lipid profile. Arylalkylamine vanadium compounds also showed antidiabetic effects in severely diabetic rats with undetectable circulating insulin. These results demonstrate the feasibility of insulin-like regulation in the complete absence of insulin and downstream of the insulin receptor. This represents a novel therapeutic approach for diabetic patients with severe insulin resistance

    Global, regional, and national estimates of tuberculosis incidence and case detection among incarcerated individuals from 2000 to 2019: a systematic analysis.

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    People who are incarcerated are at high risk of developing tuberculosis. We aimed to estimate the annual global, regional, and national incidence of tuberculosis among incarcerated populations from 2000 to 2019. We collected and aggregated data for tuberculosis incidence and prevalence estimates among incarcerated individuals in published and unpublished literature, annual tuberculosis notifications among incarcerated individuals at the country level, and the annual number of incarcerated individuals at the country level. We developed a joint hierarchical Bayesian meta-regression framework to simultaneously model tuberculosis incidence, notifications, and prevalence from 2000 to 2019. Using this model, we estimated trends in absolute tuberculosis incidence and notifications, the incidence and notification rates, and the case detection ratio by year, country, region, and globally. In 2019, we estimated a total of 125鈥105 (95% credible interval [CrI] 93鈥736-165鈥318) incident tuberculosis cases among incarcerated individuals globally. The estimated incidence rate per 100鈥000 person-years overall was 1148 (95% CrI 860-1517) but varied greatly by WHO region, from 793 (95% CrI 430-1342) in the Eastern Mediterranean region to 2242 (1515-3216) in the African region. Global incidence per 100鈥000 person-years between 2000 and 2012 among incarcerated individuals decreased from 1884 (95% CrI 1394-2616) to 1205 (910-1615); however, from 2013 onwards, tuberculosis incidence per 100鈥000 person-years was stable, from 1183 (95% CrI 876-1596) in 2013 to 1148 (860-1517) in 2019. In 2019, the global case detection ratio was estimated to be 53% (95% CrI 42-64), the lowest over the study period. Our estimates suggest a high tuberculosis incidence rate among incarcerated individuals globally with large gaps in tuberculosis case detection. Tuberculosis in incarcerated populations must be addressed with interventions specifically tailored to improve diagnoses and prevent transmission as a part of the broader global tuberculosis control effort. National Institutes of Health. [Abstract copyright: This is an Open Access article published under the CC BY 3.0 IGO license which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In any use of this article, there should be no suggestion that WHO endorses any specific organisation, products or services. The use of the WHO logo is not permitted. This notice should be preserved along with the article's original URL.

    Long-term thermal sensitivity of Earth鈥檚 tropical forests

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    The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (鈭9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per 掳C in the hottest forests (>32.2掳C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth鈥檚 climate

    XVI International Congress of Control Electronics and Telecommunications: "Techno-scientific considerations for a post-pandemic world intensive in knowledge, innovation and sustainable local development"

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    Este t铆tulo, sugestivo por los impactos durante la situaci贸n de la Covid 19 en el mundo, y que en Colombia lastimosamente han sido muy cr铆ticos, permiten asumir la obligada superaci贸n de tensiones sociales, pol铆ticas, y econ贸micas; pero sobre todo cient铆ficas y tecnol贸gicas. Inicialmente, esto supone la existencia de una capacidad de la sociedad colombiana por recuperar su estado inicial despu茅s de que haya cesado la perturbaci贸n a la que fue sometida por la catastr贸fica pandemia, y superar ese anterior estado de cosas ya que se encontraban -y a煤n se encuentran- muchos problemas locales mal resueltos, medianamente resueltos, y muchos sin resolver: es decir, habr谩 que redise帽ar y fortalecer una probada resiliencia social existente - producto del prolongado conflicto social colombiano superado parcialmente por un proceso de paz exitoso - desde la tecnociencia local; como lo indicaba Markus Brunnermeier - economista alem谩n y catedr谩tico de econom铆a de la Universidad de Princeton- en su libro The Resilient Society鈥a cuesti贸n no es preveerlo todo sino poder reaccionar鈥prender a recuperarse r谩pido.This title, suggestive of the impacts during the Covid 19 situation in the world, and which have unfortunately been very critical in Colombia, allows us to assume the obligatory overcoming of social, political, and economic tensions; but above all scientific and technological. Initially, this supposes the existence of a capacity of Colombian society to recover its initial state after the disturbance to which it was subjected by the catastrophic pandemic has ceased, and to overcome that previous state of affairs since it was found -and still is find - many local problems poorly resolved, moderately resolved, and many unresolved: that is, an existing social resilience test will have to be redesigned and strengthened - product of the prolonged Colombian social conflict partially overcome by a successful peace process - from local technoscience; As Markus Brunnermeier - German economist and professor of economics at Princeton University - indicates in his book The Resilient Society...The question is not to foresee everything but to be able to react...learn to recover quickly.Bogot

    EXISTENCE OF UNUSED MANAGED CAPACITY ON DEDICATED LANES AND AN ALTERNATIVE ON HOW TO SELL IT VIA AUCTIONS

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    This dissertation verifies whether the following two hypotheses are true: (1) High-occupancy/toll lanes (and therefore other dedicated lanes) have capacity that could still be used; (2) such unused capacity (or more precisely, 鈥渦nused managed capacity鈥) can be sold successfully through a real-time auction. To show that the second statement is true, this dissertation proposes an auction-based metering (ABM) system, that is, a mechanism that regulates traffic that enters the dedicated lanes. Participation in the auction is voluntary and can be skipped by paying the toll or by not registering to the new system. This dissertation comprises the following four components: a measurement of unused managed capacity on an existing HOT facility, a game-theoretic model of an ABM system, an operational description of the ABM system, and a simulation-based evaluation of the system. Some other and more specific contributions of this dissertation include the following: (1) It provides a definition and a methodology for measuring unused managed capacity and another important variable referred as 鈥減otential volume increase鈥. (2) It proves that the game-theoretic model has a unique Bayesian Nash equilibrium. (3) And it provides a specific road design that can be applied or extended to other facilities. The results provide evidence that the hypotheses are true and suggest that the ABM system would benefit a public operator interested in reducing traffic congestion significantly, would benefit drivers when making low-reliability trips (such as work-to-home trips), and would potentially benefit a private operator interested in raising revenue
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