3,359 research outputs found
On the Detection of CMB B-modes from Ground at Low Frequency
The primordial CMB -mode search is on the spotlight of the scientific
community due to the large amount of cosmological information that is encoded
in the primeval signal. However, the detection of this signal is challenging
from the data analysis point of view, due to the relative low amplitude
compared to the foregrounds, the lensing contamination coming from the leakage
of -modes, and the instrumental noise. Here, we studied the viability of the
detection of the primordial polarization -mode with a ground-based telescope
operating in the microwave low-frequency regime (i.e., from 10GHz-120GHz) in a
handful of different scenarios: i. the instrument's channels distribution and
noise, ii. the tensor-to-scalar ratio () detectability considering different
possible values and degrees of delensing, iii. the effect of including a
possible source of polarized anomalous microwave emission (AME), iv. the
strengths and weaknesses of different observational strategies and, v. the
atmospheric and systematic noise impact on the recovery. We focused mainly on
the removal of galactic foregrounds as well as noise contamination by applying
a full-parametric pixel-based maximum likelihood component separation
technique. Moreover, we developed a numerical methodology to estimate the
residuals power spectrum left after component separation, which allow us to
mitigate possible biases introduced in the primordial -mode power spectrum
reconstruction. Among many other results, we found that this sort of experiment
is capable of detecting Starobinsky's even when no delensing is performed
or, a possible polarized AME contribution is taken into account. Besides, we
showed that this experiment is a powerful complement to other on-ground or
satellite missions, such as LiteBIRD, since it can help significantly with the
low-frequency foregrounds characterization.Comment: 28 pages, 18 figures, submitted to JCA
Lost and found: the radial quantum number of Laguerre-Gauss modes
We introduce an operator linked with the radial index in the Laguerre-Gauss
modes of a two-dimensional harmonic oscillator in cylindrical coordinates. We
discuss ladder operators for this variable, and confirm that they obey the
commutation relations of the su(1,1) algebra. Using this fact, we examine how
basic quantum optical concepts can be recast in terms of radial modes.Comment: Some minor typos fixed
Teleagro: software architecture of georeferencing and detection of heat of cattle
The systems of livestock production contribute in a preponderant way to improve the quality of life of the communities, since it allows to support the production of the daily sustenance of the communities, to conserve the
ecosystems, to promote the conservation of the wild life and to satisfy the values and traditions cultural Latin America, with its large wilderness areas, and a privileged climate favors the maintenance of livestock, to meet the demands of food and ensure regional and global food security. In Colombia, the agricultural sector contributes approximately 11.83% of the national GDP at current prices, according to the Bank of the Republic. Likewise, the livestock industry participates with 3.6%, in comparison with other sectors of the agricultural economy, the production of Colombian cattle doubles and triples to other sectors, such as poultry, coffee and floriculture. In addition, it contributes to the generation of employment in more than 25% of the total jobs generated in the agricultural sector and approximately 7% of the total employment of the Colombian economy (http://www.banrep.gov.co/is/pib). Within agricultural production, livestock occupy 38 million hectares, being 9 times larger than the area dedicated to agriculture. However, agriculture contributes 63% of the value of agricultural production, while livestock, mainly extensive, contributes 26% (FEDEGAN, Strategic Livestock Plan 2019). The large proportion of the área with agricultural vocation dedicated to precarious extensive livestock has
explained the low agricultural productivity in Colombia, with very serious consequences for human and sustainable development. This document shows the results of the communications, software and hardware platforms to help the livestock sector to manage production
Path Planning Approach for a Quadrotor Unmanned Aerial Vehicle
A path planning method for an unmanned aerial system type quadrotor is proposed in this work. It is based on Dubins curves. Therefore, different points (initial and ending) are set for generation of several paths. Additionally, to validate the proposed model a computational resource is applied. Also, some flight dynamics limits and orientation angles computations are considered to be able to determine a simplified Dubins model. Dubins paths are commonly divided into low, medium and high altitude gains. It will depend on the altitude established for the start and end points and other configurations
Optimal and Long-Term Dynamic Transport Policy Design: Seeking Maximum Social Welfare through a Pricing Scheme.
This article presents an alternative approach to the decision-making process in transport strategy design. The study explores the possibility of integrating forecasting,
assessment and optimization procedures in support of a decision-making process designed to reach the best achievable scenario through mobility policies.
Long-term evaluation, as required by a dynamic system such as a city, is provided by a strategic Land-Use and Transport Interaction (LUTI) model. The social welfare
achieved by implementing mobility LUTI model policies is measured through a cost-benefit analysis and maximized through an optimization process throughout the evaluation period. The method is tested by optimizing a pricing policy scheme in Madrid on a cordon toll in a context requiring system efficiency, social equity and environmental quality. The optimized scheme yields an appreciable increase in social surplus through a relatively low rate compared to other similar pricing toll schemes. The results highlight the different considerations regarding mobility impacts on the case study area, as well as the major contributors to social welfare surplus. This leads the authors to reconsider the cost-analysis approach, as defined in the study, as the best option for formulating sustainability measures
Quantum metrology at the limit with extremal Majorana constellations
Quantum metrology allows for a tremendous boost in the accuracy of measurement of diverse physical parameters. The estimation of a rotation constitutes a remarkable example of this quantum-enhanced precision. The recently introduced Kings of Quantumness are especially germane for this task when the rotation axis is unknown, as they have a sensitivity independent of that axis and they achieve a Heisenberg-limit scaling. Here, we report the experimental realization of these states by generating up to 21-dimensional orbital angular momentum states of single photons, and confirm their high metrological abilities
OpenFOAM Numerical Simulations with Different Lid Driven Cavity Shapes
The finite volume method have been developed to solve the Navier-Stokes equations with primitive variables and non dimensional form. This work examine the classical benchmark problem of the lid-driven cavity at a different Reynolds range (Re = 10,100,400, 1000, 2000, 3200) and several cavity geometries. The cavity configurations include square cavity, skewed cavity, trapezoidal cavity and arcshaped cavity. The flow is assumed laminar and solved in a uniform mesh. A CFD tool with its solvers (icoFoam) will be used for this study
The ATLAS EventIndex: Full chain deployment and first operation
AbstractThe Event Index project consists in the development and deployment of a complete catalogue of events for experiments with large amounts of data, such as the ATLAS experiment at the LHC accelerator at CERN. Data to be stored in the EventIndex are produced by all production jobs that run at CERN or the GRID; for every permanent output file, a snippet of information, containing the file unique identifier and the relevant attributes for each event, is sent to the central catalogue. The estimated insertion rate during the LHC Run 2 is about 80 Hz of file records containing ∼15 kHz of event records. This contribution describes the system design, the initial performance tests of the full data collection and cataloguing chain, and the project evolution towards the full deployment and operation by the end of 2014
Mathematical Modelling and Identification of a Quadrotor
Motivated by the important growth of VTOL vehicles research such as quadrotors and to a small extent autonomous flight, a quadrotor dynamical model is presented in this work. The purpose of this study is to get a better understanding of its flight dynamics. It is an underactuated system. So, a simplified and clear model is needed to implement controllers on these kind of unmanned aerial systems. In addition, a computational tool is used for validation purposes. For future works embedded or intelligent control systems can be developed to control them. Gyroscopic and some aerodynamics effects are neglected
Effectiveness of a cardiovascular risk management program in the reduction of premature mortality associated to cardiovascular events in the Caribbean region of Colombia
Objectives: To establish the effectiveness of a cardiovascular risk management program [“De Todo Corazon (DTC)” program in Mutual SER-EPS] in the reduction of premature mortality associated to cardiovascular events (CVE) (male , 55 years, female , 60 years). Methods: The population eligible for the study were patients over 18 years of age affiliated to Mutual SER insurance company between June 2015 and June 2018 and residents of the Caribbean region of Colombia, enrolled or not to DTC program in which a cardiovascular event (CVE) occurred. The main outcomes considered were age of occurrence of cardiovascular events (AOCVE), age at death due to CVE (ADCVE) and years life lost (YLL). For the evaluation of the effectiveness, differences in AOCVO, ADCVO and the YPLL between the patients enrolled and nonenrolled in the DTC program were estimated using a Simple Linear Regression model. Results: A total of 3.902 CVE occurred in the study period among both groups. The enrolled patients had an average of AOCVE of 4.96 years (95% CI 3.85-6.06) higher than in non-enrolled patients. The ADCVE average was 4.64 years (95% CI 1.47 - 7.81) higher in the enrolled patients compared with the non-enrolled patients. Patients enrolled in the DTC program had on average -3.54 (95% CI -5.62 - -1.46) YLL compared to the non-enrolled patients. Conclusions: The DTC program in Mutual SER-EPS was effective to delay the AOCVE, ADCVE and YPLL. DTC program is an effective strategy to reduce the incidence and premature mortality due to CVE in the Caribbean region of Colombia
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