1,123 research outputs found
Regional Heterogeneity, Geography and Agglomeration Effects in Efficiency Analysis: The Case of Dairy Farming in Europe
La relación de la gestión municipal en la satisfacción de la población del distrito de Tacna 2019
La presente investigación titulada la relación en la Gestión Municipal en la satisfacción de la población del distrito de Tacna del año 2019, fue realizado en el distrito de Tacna, departamento de Tacna. Se tuvo como problema general como se relaciona la gestión municipal en la satisfacción de la población en el distrito de Tacna. Objetivo: Determinar de qué manera se relaciona la gestión municipal en la satisfacción de la población en el distrito de Tacna, 2019. Métodos: La población y muestra estuvo comprendida por los representantes de los grupos sociales de la Municipalidad Provincial de Tacna. Se utilizó el método universal: el método científico – dialéctica el diseño de la presente investigación es de diseño no experimental, correlacional y longitudinal. Es no experimental porque evalúa el fenómeno de estudio en un determinado momento, sin manipular ninguna variable. Es correlacional debido a que mide la relación de variables. Y es transeccional, debido a que evalúa el fenómeno a través del tiempo. Llegando a la conclusión de que la gestión municipal tiene una relación muy significativa en la satisfacción de la población en el distrito de Tacna debido a una buena gestión municipal; se puede analizar que hay una deficiente satisfacción de la población respecto a la gestión social y ejecución y cumplimiento de obras siendo esto el estado real en la satisfacción de la población; por cuanto ofrezco una síntesis de información teórica y práctica para implementar y formular políticas
Precision-Aided Partial Ambiguity Resolution Scheme for GNSS Attitude Determination
The use of carrier phase data play an important role for high-precision Global Navigation Satellite Systems (GNSS) positioning solutions, such as Real-Time Kinematic (RTK). Similarly, precise orientation information can be obtained with multi-antenna setups which exploit carrier phase observables. The availability of high precision navigation solutions is, however, subject to the Integer Ambiguity Resolution (IAR) performance. IAR is the process of mapping the real-valued carrier ambiguities to integer ones, enhancing the attitude solution by virtue of the cross-correlation with the estimated integer ambiguities. Unfortunately, IAR is known to suffer from dimensionality course or, in other words, the chances for finding the correct vector of integers reduces with the number of ambiguities.
This work focuses on improving the availability of high precision attitude estimates by means of using a Partial Ambiguity Resolution (PAR) scheme. PAR relaxes the condition of estimating the complete vector of ambiguities and, instead and finds a subset of them to maximize the availability. A new formulation for attitude determination using quaternion rotation within a precision-driven PAR scheme is proposed. Numerical simulations are used to showcase the attitude determination performance with a conventional Full Ambiguity Resolution (FAR) and a precision-aided PAR approach
Marketing Turístico: desde una perspectiva bibliométrica en los deportes de aventura
The investigation of Touristic Marketing and Adventure Sports goes with special number of articles that has contain information of different authors. The objective of this study seeks to generate opinions and comments on the scope of marketing in tourism. However, there are cases of studies bibliometric about the research of interviews about the theme. In this article the evaluation of the scientific product between the years 2016-2021; based on the information of Scopus, Web of Science (WoS), Taylor & Francis (T&F) y Science Direct (SD), through the bibliometric method, making use of the Bibliometrix and PowerBI tools, that allows the identification of the years, institutions, journal, authors most known, documents, countries, and keywords with most participation of scientific expandations of Marketing Touristic and Adventure Sports. For that it gets done analysis of a description that contains a selective of 25 documents based on predefined criteria to include and exclude studies of Scopus, WoS, T&F y SD. In the results of the research WoS y T&F have mayor number of publications and the other part of the documents are published in that Journal of Sport & Tourism. The country with the greatest significant in publications of the United States. Finally, in the research bibliographic the evidence of knowledge presents expandation of growing the opportunity of bringing authors without, evidence in the discipline of tourism. La investigación en Marketing Turístico y Deportes de Aventura cuenta con un apreciable número de artículos que han contextualizado la corriente doctrinal según los diferentes autores. Sin embargo, son escasos los estudios bibliométricos en las revistas científicas acerca de la temática abordada. El objetivo de este estudio es llenar el vacío en la literatura mediante el análisis de documentos de investigación sobre marketing en el turismo de aventura. La importancia de este artículo radica en la evaluación de la producción científica entre los años 2016-2021; en las bases de datos Scopus, Web of Science (WoS), Taylor & Francis (T&F) y Science Direct (SD), a través del método bibliométrico se utilizó las herramientas Bibliomterix y PowerBI que permiten la identificación de los años, instituciones, revistas, autores, documentos citados, países y palabras clave con mayor participación en las divulgaciones científicas acerca del Marketing Turístico y Deportes de Aventura. Para ello, se realizó un análisis descriptivo que consistió en la selección de 25 documentos extraídos mediante criterios de inclusión y exclusión de las bases Scopus, WoS, T&F y SD. Entre los resultados se observa que la WoS y T&F, concentran la mayor cantidad de publicaciones y gran parte de los documentos se encuentran publicados en la Journal of Sport & Tourism. El país con más publicaciones fue Estados Unidos. Finalmente, en el seguimiento bibliográfico se evidencia que el campo de conocimiento presenta un crecimiento exponencial y resalta como oportunidad para el ingreso de nuevos autores, sin evidenciar saturación en la disciplina del turismo.
Fresnel solar cooling plant for buildings: Optimal operation of an absorption chiller through inverse modelling
Increasing comfort conditions in buildings imply higher energy demands. However, these needs can be mitigated by solar cooling solutions. These systems, such as absorption chillers, are complex and require stable operation, with strict control to maximise the solar fraction and minimise gas consumption. This is incompatible with the variability of renewable resources, so they are often coupled with auxiliary gas systems. Although gas-free operation is possible if these systems are optimally controlled, they would require special supervision. This paper aims to develop an experimental validation of an inverse model to manage an absorption chiller coupled with a solar cooling plant. To know its real behaviour, long-term experiments have been performed using this plant, which consists of a linear Fresnel solar collector and an auxiliary natural gas boiler. The inverse model is used as a predictive control tool to decide the auxiliary boiler commands of the absorption chiller to optimise its operation: maximum cooling production by minimising gas consumption and maximising solar contribution. It has been identified with data from two weeks and validated with data from one summer month. Results show that the model estimates, on a time base of fewer than 30 min, are acceptable with errors of less than 5%. In addition, the maximum error of the estimated seasonal COP and the renewable fraction are less than 6% per day. Therefore, the results prove the usefulness of the proposal as a predictive control for optimal operation. Furthermore, it could be used as a baseline for preventive maintenance. If the proposed model is used for optimal management of the absorption chiller, the thermal efficiency of the plant increases significantly, doubling the solar contribution. As a result, the gas consumption of the solar cooling plant is halved and the total cost of air conditioning the building decreases by 16%.Comisión Europea A_B.4.3_02
Adaptative Cover to Achieve Thermal Comfort in Open Spaces of Buildings: Experimental Assessment and Modelling
The global need for healthy and safe open spaces faces continuous temperature rise due to the heat island phenomenon and climate change. This problem requires new strategies for improving the habitability of open spaces (indoor and outdoor conditions in buildings). These techniques include reducing solar radiation, reducing the temperature of surrounding surfaces, and reducing the air temperature. The radiant solutions are essential for outdoor comfort, both in summer and in winter. They are easy to integrate into open spaces. This study explores a new concept of radiant solutions adapted for outdoor spaces. The solution was evaluated in a test cell to obtain its thermal behaviour in different operation conditions. Solutions were optimised for operating in a cooling regimen since it has been identified that the demands for comfort in open spaces in hot climates during the most severe summer months are more pronounced. Experimental results have allowed getting an inverse model to analyse the thermal behaviour of the solution. The inverse model achieved high precision in its estimations. Also, it facilitated knowing the radiant and convective effects. Only the radiant heat flux is relevant in open spaces with a low level of air confinement. Finally, the discussion describes the application of the proposed model. The model allows the replicability of the solution—creating new designs (integration) or evaluating into different operating conditions of the system. This discussion demonstrates the high level of knowledge acquired in the characterisation of the solution studied.e European Commission / European Regional Development Funds (ERDF) UIA03-301-CartujaQanat of Urban Innovative Action (UIA
Polifarmacia y prescripción de medicamentos potencialmente no apropiados en ancianos.
La prescripción de medicamentos en pacientes ancianos es y ha sido complejadebido a la influencia de los cambios fisiológicos de la edad en el metabolismode estos, a los sesgos de selección de diversos ensayos clínicos que excluyenpacientes geriátricos, al mayor número de comorbilidades y al mayor riesgode toxicidad e interacciones farmacológicas. De esta manera, los pacientesgeriátricos han sido blanco de la polifarmacia y de la prescripción inapropiadade medicamentos, y como consecuencia de ello, de mala adherencia alos esquemas terapéuticos, deterioro en la calidad de vida, cascadas deprescripción y en general mayor morbimortalidad. Por esta razón, se handiseñado herramientas para la clasificación de prescripciones inadecuadas quebuscan otorgarle al médico un apoyo para el correcto manejo farmacológicode estos pacientes, de estos, los Criterios de Beers y los Criterios STOP-STARThan sido los más utilizados
A Collaborative RTK Approach to Precise Positioning for Vehicle Swarms in Urban Scenarios
Location information is fundamental in nowadays society and key for prospective driverless vehicles and a plethora of safety-critical applications. Global Navigation Satellite Systems (GNSS) constitute the main information supplier for outdoor positioning, with worldwide all-weather availability. While the use of GNSS carrier phase observations leads to precise location estimates, its performance can be easily jeopardized in urban scenarios, where satellite availability may be limited or observations may be corrupted by harsh propagation conditions. The satellite shortage is especially relevant for Real Time Kinematic (RTK), whose capability to estimate a precise positioning solution rapidly decays with weak observation models. To address this limitation, this article introduces the concept of collaborative RTK (C-RTK), an approach to precise positioning using swarms of vehicles, where a set of users participate in the vehicle network. The idea is that users with good satellite visibility assist users that evolve in constrained environments. This work introduces the C-RTK functional model, an estimation solution and associated performance bounds. Illustrative Monte Carlo simulation results are provided, which highlight that, by exploiting the cross-correlation terms present among the users' observations, C-RTK improves their positioning their of accuracy and availability
Polifarmacia y prescripción de medicamentos potencialmente no apropiados en ancianos.
La prescripción de medicamentos en pacientes ancianos es y ha sido complejadebido a la influencia de los cambios fisiológicos de la edad en el metabolismode estos, a los sesgos de selección de diversos ensayos clínicos que excluyenpacientes geriátricos, al mayor número de comorbilidades y al mayor riesgode toxicidad e interacciones farmacológicas. De esta manera, los pacientesgeriátricos han sido blanco de la polifarmacia y de la prescripción inapropiadade medicamentos, y como consecuencia de ello, de mala adherencia alos esquemas terapéuticos, deterioro en la calidad de vida, cascadas deprescripción y en general mayor morbimortalidad. Por esta razón, se handiseñado herramientas para la clasificación de prescripciones inadecuadas quebuscan otorgarle al médico un apoyo para el correcto manejo farmacológicode estos pacientes, de estos, los Criterios de Beers y los Criterios STOP-STARThan sido los más utilizados
Precision-Aided Partial Ambiguity Resolution Scheme for Instantaneous RTK Positioning
The use of carrier phase data is the main driver for high-precision Global Navigation
Satellite Systems (GNSS) positioning solutions, such as Real-Time Kinematic (RTK). However, carrier
phase observations are ambiguous by an unknown number of cycles, and their use in RTK relies on the
process of mapping real-valued ambiguities to integer ones, so-called Integer Ambiguity Resolution
(IAR). The main goal of IAR is to enhance the position solution by virtue of its correlation with the
estimated integer ambiguities. With the deployment of new GNSS constellations and frequencies, a
large number of observations is available. While this is generally positive, positioning in medium
and long baselines is challenging due to the atmospheric residuals. In this context, the process
of solving the complete set of ambiguities, so-called Full Ambiguity Resolution (FAR), is limiting
and may lead to a decreased availability of precise positioning. Alternatively, Partial Ambiguity
Resolution (PAR) relaxes the condition of estimating the complete vector of ambiguities and, instead,
finds a subset of them to maximize the availability. This article reviews the state-of-the-art PAR
schemes, addresses the analytical performance of a PAR estimator following a generalization of the
Cramér–Rao Bound (CRB) for the RTK problem, and introduces Precision-Driven PAR (PD-PAR).
The latter constitutes a new PAR scheme which employs the formal precision of the (potentially fixed)
positioning solution as selection criteria for the subset of ambiguities to fix. Numerical simulations
are used to showcase the performance of conventional FAR and FAR approaches, and the proposed
PD-PAR against the generalized CRB associated with PAR problems. Real-data experimental analysis
for a medium baseline complements the synthetic scenario. The results demonstrate that (i) the
generalization for the RTK CRB constitutes a valid lower bound to assess the asymptotic behavior
of PAR estimators, and (ii) the proposed PD-PAR technique outperforms existing FAR and PAR
solutions as a non-recursive estimator for medium and long baselines
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