1,698 research outputs found
A Model Study of the Global Emissions of Terpenoid Volatile Organic Compounds from Terrestrial Vegetation in the Last Millennium
This thesis is a global study of the changes in the plant emissions of the dominant Biogenic Volatile Organic Compounds (BVOC) in the last millennium resulting from changing environmental conditions, largely induced by humans. BVOC emitted by vegetation have multiple impacts on atmospheric chemistry and physics, for instance changes in BVOC emissions significantly change the concentrations of aerosol in continental regions, affect ozone formation and change the oxidizing capacity of the troposphere. These processes are relevant from a climate change and air quality perspectives. The variability of global fluxes of isoprene, monoterpenes and sesquiterpenes (terpenoid BVOC) over the last millennium is evaluated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN). The model is driven with meteorology input data from an Earth System Model, CO2 atmospheric concentrations estimated from ice samples and model reconstructions of the global changes of vegetation.
The results show that global isoprene emissions have decreased 7.3%, monoterpene emissions have increased 9.8% and sesquiterpene emissions have increased 15.1% during the period 1950-1990 as compared to 1000-1800. The results suggest that the variation of isoprene emissions is governed by land-use changes, while monoterpenes and sesquiterpenes variations are dominated by temperature. Regional changes on the isoprene, monoterpene and sesquiterpene emission distribution are larger than global changes in many locations and could have had a significant impact on the chemistry and aerosol dynamic processes in the atmosphere in the last millennium. This thesis lays a basis for a future quantification of the effect on atmospheric chemistry cycles and the organic aerosol yield from biogenic organic precursors
Desarrollo de un sistema de inventarios para la tienda naturista El Alquimista
Este trabajo de grado describe el desarrollo del modelo de inventario para mejorar el manejo del mismo de la TIENDA NATURISTA EL ALQUIMISTA, dedicada a la distribución y venta de productos relacionados con la medicina alternativa ubicada en diferentes municipios de la sabana de Bogotá.
Para el desarrollo del proyecto se establecieron tres ejes centrales. El primero corresponde a la cuantificación de los productos que hacen parte del inventario ¿Qué medicamentos se deben comprar?, el segundo corresponde al comportamiento que presentan estos medicamentos en su demanda, así mismo, establecer el modelo de inventario acorde a este comportamiento, y el tercero corresponde a una simulación de Monte Carlo del modelo para verificar que los resultados efectivamente son correctos, finalizando con la creación e implementación de políticas e indicadores para mejorar el proceso de almacenamiento y compras de la empresa.
Para la gestión de inventarios se realizó el análisis de la información cuantitativa con que se contaba. Se comenzó organizando los datos de los medicamentos que demandarían mayor cuidado y control de acuerdo a los cuatro criterios de clasificación ABC mencionados en el libro Inventarios, manejo y control (Guerrero 2009)1.
Con los resultados obtenidos se realizó un estudio de las probabilidades de la demanda para encontrar el modelo de pronóstico más confiable como lo es el ARIMA, donde se calcularon los costos en los que se incurre al querer establecer cualquier modelo de inventario. Al evaluar estos estudios se procedió a determinar el modelo de gestión de inventarios que mejor se ajustará a las características de la demanda, al entorno administrativo y los factores situacionales que aquejan a la empresa. El modelo que fue seleccionado establecerá las políticas de inventario para cada uno de los medicamentos clasificados como tipo A; una vez establecidos estos lineamientos para el control del inventario, se evaluará con una simulación de Monte Carlo, para observar el comportamiento de las mismas en el tiempo y garantizar así una correcta formulación del indicador.This paper describes the development grade inventory model to improve its handling of LA TIENDA NATURISTA EL ALQUIMISTA, dedicated to the distribution and sale of alternative medicine related located in different municipalities in the savannah of Bogotá products.
For the project three main components were established. The first is the quantification of the products that are part of the inventory What medications should buy?, the second corresponds to the behavior presented by these drugs in its application, likewise, establish the inventory model according to this behavior, and third party is a Monte Carlo simulation model to verify that the results are indeed correct, ending with the creation and implementation of policies and indicators to improve the storage process and purchases of the company.
Inventory management for the analysis of quantitative information that had performed. It began organizing the data of medicines which would require greater care and control according to the four ABC classification criteria mentioned in the book inventories, management and control (Guerrero 2009).
With the results a study of the likely demand was made to find the most reliable model as is the ARIMA, where the costs that are incurred in wanting to establish any pattern of inventory is calculated prognosis. When evaluating these studies we proceeded to determine the inventory management model that best adjusted to the characteristics of demand, the administrative environment and situational factors that affect the company. The model was selected inventory policies established for each of the drugs classified as type A; once established these guidelines for inventory control, it will be evaluated with a Monte Carlo simulation to observe the behavior of the same in time and guarantee a correct formulation of the indicato
Added value of assimilating springtime Arctic sea ice concentration in summer-fall climate predictions
Prediction skill of continental climate in the Northern Hemisphere (NH) midlatitudes is generally limited throughout the year in dynamical seasonal forecast systems. Such limitations narrow the range of possible applications by different stakeholders. Improving the predictive capacity in these regions has been a challenging task. Sea ice is a central component of the Arctic climate system and a local source of climate predictability, yet its state is often not fully constrained in dynamical forecast systems. Using the EC-Earth3 climate model, we study the added value of assimilating observed Arctic sea ice concentration on the NH extratropical climate in retrospective forecasts of summer and fall, initialized every spring over 1992–2019. Predictions in the North Atlantic and Eurasia benefit from better initialization of sea ice in the Atlantic sector of the Arctic in a two-step mechanism. Initially, sea ice influences the central North Atlantic Ocean through an atmospheric bridge that develops in the first forecast weeks, subsequently leading to preserved skill in the sea surface temperatures (SSTs) throughout summer and early fall. Secondly, these long-lasting SST improvements provide better surface boundary conditions for the atmosphere and lead to more skillful predictions of circulation and surface climate in the Euro-Atlantic and Asian regions. In addition, our findings suggest that fully coupled ocean-atmosphere-sea ice models are likely necessary to study linkages between Arctic sea ice and midlatitudes, by better representing the interactions and feedbacks between the different components of the climate system.The data that support the findings of this study are available upon reasonable request from the authors. This work was funded by the European Union projects APPLICATE (Grant 727862), INTAROS (Grant 727890), and ESA/CMUG-CCI3. J C A N received financial support from the Spanish Ministerio de Ciencia, Innovación y Universidades through a Juan de la Cierva personal grant (FJCI-2017-34027). J G-S was supported by the Spanish 'Ramón y Cajal' programme (RYC-2016-21181). All the data were downloaded from their original source, converted to NetCDF in a format designed for efficient analysis and quality checked at several levels. Etienne Tourigny, Pierre-Antoine Bretonnière, Margarida Samsó Cabré, Núria Pérez Zanón and An Chi Ho are acknowledged for their help with technical aspects. We thank the two anonymous reviewers for their valuable comments on the manuscript.Peer ReviewedPostprint (published version
Summer predictions of Arctic sea ice edge in multi-model seasonal re-forecasts
In this study, the forecast quality of 1993–2014 summer seasonal predictions of five global coupled models, of which three are operational seasonal forecasting systems contributing to the Copernicus Climate Change Service (C3S), is assessed for Arctic sea ice. Beyond the Pan-Arctic sea ice concentration and extent deterministic re-forecast assessments, we use sea ice edge error metrics such as the Integrated Ice Edge Error (IIEE) and Spatial Probability Score (SPS) to evaluate the advantages of a multi-model approach. Skill in forecasting the September sea ice minimum from late April to early May start dates is very limited, and only one model shows significant correlation skill over the period when removing the linear trend in total sea ice extent. After bias and trend-adjusting the sea ice concentration data, we find quite similar results between the different systems in terms of ice edge forecast errors. The highest values of September ice edge error in the 1993–2014 period are found for the sea ice minima years (2007 and 2012), mainly due to a clear overestimation of the total extent. Further analyses of deterministic and probabilistic skill over the Barents–Kara, Laptev–East Siberian and Beaufort–Chukchi regions provide insight on differences in model performance. For all skill metrics considered, the multi-model ensemble, whether grouping all five systems or only the three operational C3S systems, performs among the best models for each forecast time, therefore confirming the interest of multi-system initiatives building on model diversity for providing the best forecasts.This study was partly funded by the H2020-APPLICATE project, EU grant number 727862. JCAN acknowledges the Spanish Ministry of Science, Innovation and Universities for the personal grant Juan de la Cierva FJCI-2017-34027, PRACE for awarding access to MareNostrum at Barcelona Supercomputing Center (BSC), and ESA/CMUG-CCI3 for financial support. PO work was funded by the Ramon y Cajal grant RYC-2017-22772.Peer ReviewedPostprint (author's final draft
Improving Arctic weather and seasonal climate prediction: recommendations for future forecast systems evolution from the European project APPLICATE
The Arctic environment is changing, increasing the vulnerability of local communities and ecosystems, and impacting its socio-economic landscape. In this context, weather and climate prediction systems can be powerful tools to support strategic planning and decision-making at different time horizons. This article presents several success stories from the H2020 project APPLICATE on how to advance Arctic weather and seasonal climate prediction, synthesizing the key lessons learned throughout the project and providing recommendations for future model and forecast system development.The results discussed in this article were supported by the project APPLICATE (727862), funded by the European Union's Horizon 2020 research and innovation programme. PO was additionally supported by the Spanish fellowship RYC-2017-22772.Peer ReviewedArticle signat per 29 autors/es: Pablo Ortega (1), Edward W. Blockley (2), Morten Køltzow (3), François Massonnet (4), Irina Sandu (5), Gunilla Svensson (6), Juan C. Acosta Navarro (1), Gabriele Arduini (5), Lauriane Batté (7), Eric Bazile (7), Matthieu Chevallier (8), Rubén Cruz-García (1), Jonathan J. Day (5), Thierry Fichefet (4), Daniela Flocco (9), Mukesh Gupta (4), Kerstin Hartung (6,10), Ed Hawkins (9), Claudia Hinrichs (11), Linus Magnusson (5), Eduardo Moreno-Chamarro (1), Sergio Pérez-Montero (1), Leandro Ponsoni (4), Tido Semmler (11), Doug Smith (2), Jean Sterlin (4), Michael Tjernström (6), Ilona Välisuo (7,12), and Thomas Jung (11,13) // (1) Barcelona Supercomputing Center, Barcelona, Spain | (2) Met Office, Exeter, UK | (3) Norwegian Meteorological Institute, Oslo, Norway | (4) Université catholique de Louvain, Earth and Life Institute, Georges Lemaître Centre for Earth and Climate Research, Louvain-la-Neuve, Belgium | (5) European Centre for Medium-Range Weather Forecasts, Reading, UK | (6) Department of Meteorology, Stockholm University, Stockholm, Sweden | (7) CNRM, Université de Toulouse, Météo-France, CNRS, Toulouse, France | (8) Météo-France, Toulouse, France | (9) National Centre for Atmospheric Science, Department of Meteorology, University of Reading, Reading, UK. | (10) Now at: Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany | (11) Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany | (12) Now at: Meteorology Unit, Finnish Meteorological Institute, Helsinki, Finland | (13) Department of Physics and Electrical Engineering, University of Bremen, Bremen, GermanyPostprint (published version
Principales estrategias para la prevención de enfermedades laborales mediante las políticas del Sistema de Seguridad y Salud en el Trabajo aplicada a los trabajadores de la empresa Banco Mujer durante el periodo 2022
Emplear principales estrategias para la prevención de enfermedades laborales mediante las políticas del Sistema de Seguridad y Salud en el Trabajo aplicada a los trabajadores de la empresa Banco Mujer durante el periodo 2022.
También se definirán las directrices de obligatorio cumplimiento para implementar el sistema de gestión de la seguridad y salud en el trabajo SG-SST del Banco Mundo Mujer, que deben ser aplicadas por el empleador y todos los colaboradores, garantizando la seguridad y protección a la salud de todos a través de la promoción de la salud y de la identificación, evaluación y control de los riesgos ocupacionales.
Para esta investigación la cual pretende implementar un sistema de gestión de seguridad y salud laboral se utilizará el tipo de investigación descriptiva, ya que se quiere analizar cómo es la situación de la empresa, en cuanto al análisis de las principales estrategias para la prevención de enfermedades laborales a través de las políticas del Sistema de Seguridad y Salud en el Trabajo para los trabajadores de la empresa Banco Mundo Mujer.
El tipo de estudio que se trabaja es el inductivo debido a que los estudios de las estrategias se darán a través de la observación; y deductivo porque se utilizará para verificar y explicar el fenómeno observado; lo cual permite obtener un diagnóstico real y un pleno conocimiento de la situación de la empresa en cuanto a las políticas de seguridad y salud laboral en el trabajo.Employ main strategies for the prevention of occupational diseases through the policies of the Occupational Safety and Health System applied to the workers of the company Banco Mujer during the period 2022.
It will also define the mandatory guidelines to implement the occupational safety and health management system SG-SST of Banco Mundo Mujer, which must be applied by the employer and all employees, ensuring the safety and health protection of all through the promotion of health and the identification, evaluation and control of occupational risks.
For this research, which aims to implement an occupational health and safety management system, a descriptive type of research will be used, since we want to analyze the situation of the company, in terms of the analysis of the main strategies for the prevention of occupational diseases through the policies of the Occupational Health and Safety System for the workers of the company Banco Mundo Mujer.
The type of study is inductive, because the study of the strategies will be done through observation; and deductive because it will be used to verify and explain the observed phenomenon; which allows obtaining a real diagnosis and a full knowledge of the company's situation regarding the policies of occupational safety and health at work
Using EC-Earth for climate prediction research
Climate prediction at the subseasonal to interannual time range is now performed routinely and operationally by an increasing number of institutions. The feasibility of climate prediction largely depends on the existence of slow and predictable variations in the ocean surface temperature, sea ice, soil moisture and snow cover, and on our ability to model the atmosphere’s interactions with those variables. Climate prediction is typically performed with statistical-empirical or process-based models. The two methods are complementary. Although forecasting systems using global climate models (GCMs) have made substantial progress in the last few decades (Doblas-Reyes et al., 2013), systematic errors and misrepresentations of key processes still limit the value of dynamical prediction in certain areas of the globe. At the same time, model initialisation, ensemble generation, understanding the processes at the origin of predictability, forecasting extremes, bias adjustment and model evaluation are all challenging aspects of the climate prediction problem. Addressing them requires both a large base of researchers with expertise in physics, mathematics, statistics, high-performance computing and data analysis interested in climate prediction issues and a tool for them to work with. This article illustrates how one of these tools, the EC-Earth climate model (Box A), has been used to train scientists in climate prediction and to address scientific challenges in this field. The use of model components from ECMWF’s Integrated Forecasting System (IFS) in EC-Earth means that some of the results obtained with EC-Earth can feed back into ECMWF’s activities. EC-Earth has been run extensively on ECMWF’s high-performance computing facility (HPCF), among a range of HPCFs across Europe and North America. The availability of ECMWF’s HPCF to EC-Earth partners, including the use of the successful ECMWF Special Project programme, means that a substantial amount of EC-Earth’s collaborative work, both within the consortium and with ECMWF, takes place on this platform.Postprint (published version
Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an
Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV
Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan
This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good
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