5,328 research outputs found
Investment portfolio trading based on Markov chain and fuzzy logic
In the present paper, a trading strategy is proposed for a portfolio composed of shares in the stock exchange. The proposed strategy is based mainly on three blocks: 1) a K-means clustering algorithm is used to determine and learn the internal hidden patterns in the time series of stock market prices, 2) a pattern predictor is performed based on a simple Markov chain, and 3) a fuzzy inference system take the decision to trade based on the estimation. The fuzzy inference system is composed of the rules provided by an expert trader. The performance of the trading algorithm is validated through simulations using real prices of
the Mexican stock exchange
An observational case study of synergies between an intense heat wave and the urban heat island in Beijing
The focus of this study is an intense heat episode that occurred on 9–13 July 2017 in Beijing, China, that resulted in severe impacts on natural and human variables, including record-setting daily electricity consumption levels. This event was observed and analyzed with a suite of local and mesoscale instruments, including a high-density automated weather station network, soil moisture sensors, and ground-based vertical instruments (e.g., a wind profiler, a ceilometer, and three radiometers) situated in and around the city, as well as electric power consumption data and analysis data from the U.S. National Centers for Environmental Prediction. The results show that the heat wave originated from dry adiabatic warming induced by the dy-namic downslope and synoptic subsidence. The conditions were aggravated by the increased air humidity during subsequent days, which resulted in historically high records of the heat index (i.e., an index repre-senting the apparent temperature that incorporates both air temperature and moisture). The increased thermal energy and decreased boundary layer height resulted in a highly energized urban boundary layer. The differences between urban and rural thermal conditions throughout almost the entire boundary layer were enhanced during the heat wave, and the canopy-layer urban heat island intensity (UHII) reached up to 8°C at a central urban station at 2300 local standard time 10 July. A double-peak pattern in the diurnal cycle of UHIIs occurred during the heat wave and differed from the single-peak pattern of the decadal average UHII cycles. Different spatial distributions of UHII values occurred during the day and night
Testing Gaussianity on Archeops Data
A Gaussianity analysis using a goodness-of-fit test and the Minkowski
functionals on the sphere has been performed to study the measured Archeops
Cosmic Microwave Background (CMB) temperature anisotropy data for a 143 GHz
Archeops bolometer. We consider large angular scales, greater than 1.8 degrees,
and a large fraction of the North Galactic hemisphere, around 16%, with a
galactic latitude b > 15 degrees.
The considered goodness-of-fit test, first proposed by Rayner & Best (1989),
has been applied to the data after a signal-to-noise decomposition. The three
Minkowski functionals on the sphere have been used to construct a chi-square
statistic using different thresholds. The first method has been calibrated
using simulations of Archeops data containing the CMB signal and instrumental
noise in order to check its asymptotic convergence. Two kind of maps produced
with two different map-making techniques (coaddition and Mirage) have been
analysed.
Archeops maps for both Mirage and coaddition map-making, have been found to
be compatible with Gaussianity. From these results we can exclude a dust and
atmospheric contamination larger than 7.8% (90% CL). Also the non-linear
coupling parameter f_{nl} can be constrained to be -800 < f_{nl} < 1100 at the
95% CL and on angular scales of 1.8 degrees. For comparison, the same method
has been applied to data from the NASA WMAP satellite in the same region of
sky. The 1-year and 3-year releases have been used. Results are compatible with
those obtained with Archeops, implying in particular an upper limit for f_{nl}
on degree angular scales.Comment: A&A accepted. The limits on the contamination and the fnl parameter
have been improve
Integrating clinical research in an operative screening and diagnostic breast imaging department: First experience, results and perspectives using microwave imaging.
Clinical research is crucial for evaluating new medical procedures and devices. It is important for healthcare units and hospitals to minimize the disruptions caused by conducting clinical studies; however, complex clinical pathways require dedicated recruitment and study designs.This work presents the effective introduction of novel microwave breast imaging (MBI), via MammoWave apparatus, into the clinical routine of an operative screening and diagnostic breast imaging department for conducting a multicentric clinical study. Microwave breast imaging, using MammoWave apparatus, was performed on volunteers coming from different clinical pathways. Clinical data, comprising demographics and conventional radiologic reports (used as reference standard), was collected; a satisfaction questionnaire was filled by every volunteer. Microwave images were analyzed by an automatic clinical decision support system, which quantified their corresponding features to discriminate between breasts with no relevant radiological findings (NF) and breasts with described findings (WF). Conventional breast imaging (DBT, US, MRI) and MBI were performed and adapted to assure best clinical practices and optimum pathways. 180 volunteers, both symptomatic and asymptomatic, were enrolled in the study. After microwave images' quality assessment, 48 NF (15 dense) and 169 WF (88 dense) breasts were used for the prospective study; 48 (18 dense) breasts suffered from a histology-confirmed carcinoma. An overall sensitivity of 85.8 % in breasts lesions' detection was achieved by the microwave imaging apparatus. An optimum recruitment strategy was implemented to assess MBI. Future trials may show the clinical usefulness of microwave imaging, which may play an important role in breast screening. [Abstract copyright: © 2023 The Authors.
SDSS-IV MANGA: Spatially Resolved Star Formation Main Sequence and LI(N)ER Sequence
We present our study on the spatially resolved H_alpha and M_star relation
for 536 star-forming and 424 quiescent galaxies taken from the MaNGA survey. We
show that the star formation rate surface density (Sigma_SFR), derived based on
the H_alpha emissions, is strongly correlated with the M_star surface density
(Sigma_star) on kpc scales for star- forming galaxies and can be directly
connected to the global star-forming sequence. This suggests that the global
main sequence may be a consequence of a more fundamental relation on small
scales. On the other hand, our result suggests that about 20% of quiescent
galaxies in our sample still have star formation activities in the outer region
with lower SSFR than typical star-forming galaxies. Meanwhile, we also find a
tight correlation between Sigma_H_alpha and Sigma_star for LI(N)ER regions,
named the resolved "LI(N)ER" sequence, in quiescent galaxies, which is
consistent with the scenario that LI(N)ER emissions are primarily powered by
the hot, evolved stars as suggested in the literature.Comment: 6 pages, 4 figures. ApJ Letter accepte
Effects of carbohydrate–protein beverages on recovery of the exercise
Este artículo aporta una revisión del efecto de la coingesta de la proteína de suero de leche y proteína caseína administradas en bebidas carbohidratadas, sobre la recuperación y los parámetros del daño muscular en ejercicios de larga duración. La búsqueda se ha realizado en abril de 2013 en las bases de datos del ISI Web of Knowledge, SCOPUS, Sport Discuss, PubMed, Medline Sportdiscus, y en las bases de datos CINDOC en las redes CTI-CSIC, RESH, DICE y DIALNET cruzando los descriptores “Exercise”, “Resistance training” y “Recovery” con los términos “Ergogenic beverage”, “Casein Protein” y “Whey Protein”. La estrategia nutricional más respaldada es la ingesta de un preparado líquido carbohidratado en donde se combinan proteínas de diferentes fuentes sobre pruebas de esfuerzos prolongados similares a la competición tanto en deportes individuales como en colectivos, con resultados discrepantesThis manuscript shows a review about the effects of the whey and casein protein on recovery and parameters of muscle damage in long-term exercise. The search was conducted in April 2013 in the databases of ISI Web of Knowledge, SCOPUS, PubMed, Medline, SportDiscus, and databases on Spanish networks CINDOC CTI-CSIC, RESH, DICE, and DIALNET crossing the descriptors "Exercise", "Resistance training" and "Recovery" with the terms "Ergogenic Beverage", "Casein Protein" and "Whey Protein". The most used nutritional strategies are based in a carbohydrate beverage which combines different protein sources on prolonged exercise tests similar to sports competition, in both individual and collective sports, with discrepant result
The isolated interacting galaxy pair NGC 5426/27 (Arp 271)
We present H alpha observations of the isolated interacting galaxy pair NGC
5426/27 using the scanning Fabry-Perot interferometer PUMA. The velocity field,
various kinematical parameters and rotation curve for each galaxy were derived.
The FWHM map and the residual velocities map were also computed to study the
role of non-circular motions of the gas. Most of these motions can be
associated with the presence of spiral arms and structure such as central bars.
We found a small bar-like structure in NGC 5426, a distorted velocity field for
NGC 5427 and a bridge-like feature between both galaxies which seems to be
associated with NGC 5426. Using the observed rotation curves, a range of
possible masses was computed for each galaxy. These were compared with the
orbital mass of the pair derived from the relative motion of the participants.
The rotation curve of each galaxy was also used to fit different mass
distribution models considering the most common theoretical dark halo models.
An analysis of the interaction process is presented and a possible 3D scenario
for this encounter is also suggested.Comment: 27 pages, 15 figures, to be published in Astronomy & Astrophysic
Desarrollo de la Red Aerobiológica de Castilla y León (RACYL)
XV lnternational A.P.L.E. Symposium of Palynolog
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