bluuebunny/crossref_metadata_2025_split huggingface dataset:
Many-body quantum dynamics of an asymmetric bosonic Josephson junction
Authors: Haldar Sudip Kumar , Alon Ofir E 
Published: September 2019

Abstract
The out-of-equilibrium quantum dynamics of an interacting Bose gas trapped in a one-dimensional asymmetric double-well potential is studied by solving the many-body Schrödinger equation numerically accurately. We examine how the gradual loss of symmetry of the confining trap affects the macroscopic quantum tunneling dynamics of the system between the two wells. In an asymmetric double well, the two wells are not equivalent anymore, say, the left well is deeper than the right one. Accordingly, we analyze the dynamics by initially preparing the condensate in both the left and the right wells. The dynamics of the system is characterized by the time evolution of a few physical quantities of increasing many-body complexity, namely, the survival probability, depletion and fragmentation, and the many-particle position and momentum variances. In particular, we have examined the frequencies and amplitudes of the oscillations of the survival probabilities, the time scale for the development of fragmentation and its degree, and the growth and oscillatory behavior of the many-particle position and momentum variances. There is an overall suppression of the oscillations of the survival probabilities in an asymmetric double well, except for resonant values of asymmetry for which the one-body ground state energy in the right well matches with one of the one-body excited states in the left well, thereby resulting in resonantly enhanced tunneling from the right well ground state. Overall, depending on whether the condensate is initially prepared in the left or right well, the repulsive inter-atomic interactions affect the survival probabilities differently. For a sufficiently strong repulsive interaction, the system is found to become fragmented. The degree of fragmentation depends both on the asymmetry of the trap and the initial well in which the condensate is prepared in a non-trivial manner. Furthermore, we show that the phenomenon of resonantly enhanced tunneling can be accompanied by a large degree of fragmentation (depletion) for the strong (weak) interaction. The many-particle position and momentum variances follow the density oscillations of the system in the asymmetric double well and bears prominent signatures of the degree of depletion or fragmentation, depending on the strength of the interactions. These quantities further exhibit a fine structure signifying a breathing-mode oscillation. Finally, a universality of fragmentation for systems made of different numbers of particles but the same interaction parameter is also found and its dependence on the asymmetry is investigated. The phenomenon is robust despite the asymmetry of the junction and admits a macroscopically-large fragmented condensate characterized by a diverging many-particle position variance. This is as far as one can get from the dynamics of the density in the junction.
Stellar population analysis on the stacked spectra of double-peaked emission-line galaxies
Authors: Wang Meng-Xin , Luo A-Li 
Published: September 2019

AbstractDouble-peaked emission-line galaxies have long been perceived as objects related to merging galaxies or other phenomenawith disturbed dynamical activities, such as outflows and disk rotation. In order to find the connection between the unique activities happening in these objects and their stellar population physics, we study the stellar populations of the stacked spectra drawn from double-peaked emission-line galaxies in the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data Release 4 (DR4) and the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) databases. We group the selected double-peaked emission-line objects into 10 different types of pairs based on the Baldwin-Phillips-Terlevich (BPT) diagnosis for each pair of blueshifted and redshifted components, and then stack the spectra of each group for analysis. The software STARLIGHT is employed to fit each stacked spectrum, and the contributions of stars at different ages and metallicities are quantified for subsequent comparative study and analysis. To highlight the commonality and uniqueness in these double-peaked emitting objects, we compare the population synthesis results of the stacked spectra of double-peaked emission-line galaxies with those of their counterpart reference samples displaying single-peaked emission features. The reference samples are also selected from the LAMOST DR4 and SDSS DR7 databases. From the comparison results, we confirm the strong correlations between stellar populations and their spectral classes, and find that the double-peaked emitting phenomenon is more likely to occur in an ‘older’ stellar environment and the subgroups hosting different BPT components will show an obvious heterogeneous star formation history.
Orbital evolution of a planet with tidal dissipation in a restricted three-body system
Authors: Wang Wen-Lei , Xu Xue-Qing , Liao Xin-Hao 
Published: September 2019

Abstract
The angle between planetary spin and the normal direction of an orbital plane is supposed to reveal a range of information about the associated planetary formation and evolution. Since the orbit’s eccentricity and inclination oscillate periodically in a hierarchical triple body and tidal friction makes the spin parallel to the normal orientation of the orbital plane with a short timescale in an isolated binary system, we focus on the comprehensive effect of third body perturbation and tidal mechanism on the angle. Firstly, we extend the Hut tidal model (1981) to the general spatial case, adopting the equilibrium tide and weak friction hypothesis with constant delay time, which is suitable for arbitrary eccentricity and any angle ϑ between the planetary spin and normal orientation of the orbital plane. Furthermore, under the constraint of angular momentumconservation, the equations of orbital and ratational motion are given. Secondly, considering the coupled effects of tidal dissipation and third body perturbation, and adopting the quadrupole approximation as the third body perturbation effect, a comprehensivemodel is established by this work. Finally, we find that the ultimate evolution depends on the timescales of the third body and tidal friction. When the timescale of the third body is much shorter than that of tidal friction, the angle ϑ will oscillate for a long time, even over the whole evolution; when the timescale of the third body is observably larger than that of the tidal friction, the system may enter stable states, with the angle ϑ decaying to zero ultimately, and some cases may have a stable inclination beyond the critical value of Lidov-Kozai resonance. In addition, these dynamical evolutions depend on the initial values of the orbital elements and may aid in understanding the characteristics of the orbits of exoplanets.
DmpIRFs and DmpST: DAMPE instrument response functions and science tools for gamma-ray data analysis
Authors: Duan Kai-Kai , Jiang Wei , Liang Yun-Feng , Shen Zhao-Qiang , Xu Zun-Lei , Fan Yi-Zhong , Gargano Fabio , Garrappa Simone , Guo Dong-Ya , Lei Shi-Jun , Li Xiang , Mazziotta Mario Nicola , Salinas Maria Fernanda Munoz , Su Meng , Vagelli Valerio , Yuan Qiang , Yue Chuan , Zimmer Stephan 
Published: September 2019

Abstract
Observing GeV gamma-rays is an important goal of the DArkMatter Particle Explorer (DAMPE) for indirect dark matter searching and high energy astrophysics. In this work, we present a set of accurate instrument response functions for DAMPE (DmpIRFs) including the effective area, point-spread function and energy dispersion, which are crucial for gamma-ray data analysis based on statistics from simulation data. A dedicated software named DmpST is developed to facilitate the scientific analyses of DAMPE gamma-ray data. Considering the limited number of photons and angular resolution of DAMPE, the maximum likelihood method is adopted in DmpST to better disentangle different source components. The basic mathematics and framework regarding this software are also introduced in this paper.
Pulsar candidate classification with deep convolutional neural networks
Authors: Wang Yuan-Chao , Li Ming-Tao , Pan Zhi-Chen , Zheng Jian-Hua 
Published: September 2019

Abstract
As the performance of dedicated facilities has continually improved, large numbers of pulsar candidates are being received, which makes selecting valuable pulsar signals from the candidates challenging. In this paper, we describe the design for a deep convolutional neural network (CNN) with 11 layers for classifying pulsar candidates. Compared to artificially designed features, the CNN chooses the subintegrations plot and sub-bands plot for each candidate as inputs without carrying biases. To address the imbalance problem, a data augmentation method based on synthetic minority samples is proposed according to the characteristics of pulsars. The maximum pulses of pulsar candidates were first translated to the same position, and then new samples were generated by adding up multiple subplots of pulsars. The data augmentation method is simple and effective for obtaining varied and representative samples which keep pulsar characteristics. In experiments on the HTRU 1 dataset, it is shown that this model can achieve recall of 0.962 and precision of 0.963.
A close-in substellar object orbiting the sdOB-type eclipsing-binary system NSVS 14256825
Authors: Zhu Li-Ying , Qian Sheng-Bang , Lajús Eduardo Fernández , Wang Zhi-Hua , Li Lin-Jia 
Published: September 2019

Abstract
NSVS 14256825 is the second discovered sdOB+dMeclipsing-binary system with an orbital period of 2.65 h. This special binary was reported to contain circumbinary planets or brown dwarfs by using the timing method. However, different results were derived by different authors because of the insufficient coverage of eclipse timings. Since 2008, we have monitored this binary for about 10 yr using several telescopes and 84 new times of light minimum were obtained with high precision. It is found that the O − C curve has been increasing recently and it shows a cyclic variation with a period of 8.83 yr and an amplitude of 46.31 seconds. The cyclic change cannot be explained by magnetic activity cycles of the red dwarf component because the required energy is much larger than that radiated by this component in one whole period. This cyclic change detected in NSVS 14256825 could be explained by the light-travel time effect via the presence of a third body. The lowest mass of the third body is determined to be 14.15Mjup which is in the transition range between planets and brown dwarfs. The substellar object is orbiting around this evolved binary at an orbital separation of around 3AU with an eccentricity of 0.12. These results indicate that NSVS 14256825 is the first sdOB-type eclipsing binary consisting of a hierarchical substellar object. The detection of a close-in substellar companion to NSVS 14256825 will provide some insights on the formation and evolution of sdOB-type binaries and their companions.
LSTM neural network for solar radio spectrum classification
Authors: Xu Long , Yan Yi-Hua , Yu Xue-Xin , Zhang Wei-Qiang , Chen Jie , Duan Ling-Yu 
Published: September 2019

Abstract
A solar radio spectrometer records solar radio radiation in the radio waveband. Such solar radio radiation spanning multiple frequency channels and over a short time period could provide a solar radio spectrum which is a two dimensional image. The vertical axis of a spectrum represents frequency channel and the horizontal axis signifies time. Intrinsically, time dependence exists between neighboring columns of a spectrum since solar radio radiation varies continuously over time. Thus, a spectrum can be treated as a time series consisting of all columns of a spectrum, while treating it as a general image would lose its time series property. A recurrent neural network (RNN) is designed for time series analysis. It can explore the correlation and interaction between neighboring inputs of a time series by augmenting a loop in a network. This papermakes the first attempt to utilize an RNN, specifically long short-termmemory (LSTM), for solar radio spectrum classification. LSTM can mine well the context of a time series to acquire more information beyond a non-time series model. As such, as demonstrated by our experimental results, LSTM can learn a better representation of a spectrum, and thus contribute better classification.
Model comparison of dark energy models using deep network
Authors: Li Shi-Yu , Li Yun-Long , Zhang Tong-Jie 
Published: September 2019

Abstract
This work uses a combination of a variational auto-encoder and generative adversarial network to compare different dark energy models in light of observations, e.g., the distance modulus from type Ia supernovae. The network finds an analytical variational approximation to the true posterior of the latent parameters in the models, yielding consistent model comparison results with those derived by the standard Bayesian method, which suffers from a computationally expensive integral over the parameters in the product of the likelihood and the prior. The parallel computational nature of the network together with the stochastic gradient descent optimization technique leads to an efficient way to compare the physical models given a set of observations. The converged network also provides interpolation for a dataset, which is useful for data reconstruction.
Direct measurements of counter-streaming flows in a low-shear stellarator magnetic island topology
Authors: Perseo V. , Effenberg F. , Gradic D. , König R. , Ford O.P. , Reimold F. , Ennis D.A. , Schmitz O. , Sunn Pedersen T. 
Published: September 2019

Abstract
We report on the first experimental verification of theoretically predicted multiple bundles of counter-streaming plasma flows in the island-divertor scrape-off layer (SOL) of the stellarator Wendelstein 7-X. In the standard toroidal field direction (counter-clockwise when looking from the top) experiments, the overall structure of the SOL flows, such as flow directions, the number of flow bundles and the magnitude of the flow velocities, are consistent with numerical predictions obtained with EMC3-EIRENE. However, the modelling does not predict changes of the flow patterns with reversal of the magnetic field direction, which are experimentally observed. This indicates that additional relevant physics, such as particle drifts, will need to be incorporated into the numerical model to better describe the whole stellarator scrape-off layer behaviour.
Assessment of the Heath-Carter somatotype in adults using bioelectrical impedance analysis
Authors: Rudnev S G , Negasheva M A , Godina E Z 
Published: September 2019

Abstract
Using cross-sectional anthropometric data of 897 ethnically Russian individuals aged 16-61 years from the European part of Russia (Arkhangelsk, Moscow, and Samara), we checked the accuracy of our previously proposed bioimpedance-based formulae for the assessment of the endomorphy and mesomorphy ratings of the Heath-Carter somatotype, and suggested the revised formulae: ENDOBIA= -3,399/R + 0.992×BMI - 0.0102×BMI
2 -0.85×Sex - 5.93 (r
2=0.80; SEE=0.91); MESOBIA
= 1,578/R + 0479×BMI - 0.077×BM - 0.015×Age + 0.81×Sex - 4.14 (r
2=0.87; SEE=0.54), where R is the whole-body resistance at 50 kHz (Ohm), BMI- body mass index (kg/m2), Sex= 1 (male), 0 (female), BM- body mass (kg), Age (years). These and previously proposed formulae for adults provided close and unbiased estimates of the endomorphy and mesomorphy ratings and can be used for the assessment of the somatotype in ethnically Russian adults.
Prevalence of sarcopenia among community- dwelling, young elderly people living in Manizales, Colombia
Authors: Gonzalez-Gonzalez D R , Lopez-Salazar A M , Gonzalez-Correa C H , Curcio-Borrero C L 
Published: September 2019

Abstract
The role of sarcopenia in the elderly has received increased attention across a number of disciplines in recent years. In 2010 the European Working Group on Sarcopenia in Older People (EWGSOP) defined the condition as the loss of muscle mass plus low muscle strength or low physical performance, associated with age. There is little published research on this issue in Colombia and South America. The purpose of this study was to determine the prevalence of sarcopenia according to the criteria of the EWGSOP in the elderly population of Colombia who live in the community. Two hundred and ten subjects were studied. Muscle mass (The main component of sarcopenia as it is defined) was estimated by bioelectrical impedance analysis from which the skeletal muscle mass index was calculated. Muscle strength was measured through hand dynamometry and physical performance using the Short Physical Performance Battery (SPPB). Based on the reference values which are themselves based on U.S. or Asian population reference cut off points, an overall prevalence of sarcopenia of 52.8% or 15.7% respectively was found. The prevalence of sarcopenia in the studied population is within the ranges reported worldwide in different populations. However, there are variations depending on the cut off points and diagnostic tools used for its definition and to estimate muscle mass.
Body composition and functional capacity in patients with chronic obstructive pulmonary disease
Authors: Pineda-Zuluaga M C , González-Correa C H 
Published: September 2019

Abstract
The systemic effects associated with Chronic Obstructive Pulmonary Disease (COPD), are related to alterations in body composition in these patients. The phase angle (PA) is the most extensively used parameter of electrical bioimpedance for the diagnosis of malnutrition since it is an indicator of water distribution, body cell mass (BCM) and cellular integrity. Therefore, the aim of this study is to compare the PA values of patients with COPD and healthy individuals and to study their relationship with parameters of lung function and functional capacity. Bioelectrical impedance analysis (BIA) was carried out in order to determine PA in 35 patients with COPD and 36 controls. In the group of women, the PA value was significantly lower in those who had COPD with respect to their controls. For both sexes, in patients with COPD the relationship with PA was inversely proportional to age and gait speed and directly proportional to weight, height, hand dynamometry and fat-free mass. We conclude that, in patients with COPD, the decrease in PA is related to impaired body composition and functional capacity. In particular, the PA could be a useful parameter for evaluating not only the body composition but also the functional capacity of these patients.
Electrical impedance tomography for neonatal ventilation assessment: a narrative review
Authors: Masner A , Blasina F , Simini F 
Published: September 2019

Abstract
Neonatal care has improved dramatically over the last decades thanks to a better understanding of the transition to extrauterine life, especially due to the new respiration condition. A privileged technique to assess the filling of the lungs with air in a non-invasive way is Electrical Impedance Tomography (EIT), which is, therefore, also a tool to monitor ventilation. Out of 2427 papers on EIT from 1985 to 2018, 116 deal with EIT in neonatal care, with both the set and subset increasing at similar rates of 5 and 0.4 additional papers per year (0.03 and 0.05 papers per year) respectively. EIT can be used to determine Body position and Pneumothorax, to guide Endotracheal Tube Positioning and to monitor Ventilation Homogeneity. Moreover, real time EIT gives abundant evidence to develop new techniques such as Sustained Inflation, Protective Intended Ventilation, Minimal Invasive Surfactant Therapy, Less Invasive Surfactant Administration, Intubation-Surfactant-Extubation and Oro Pharyngeal Surfactant during their application to both animal models and patients. The low cost, non-invasive and easy graphic interpretation of EIT leads to the belief that it will have widespread use in Neonatal Medicine.
Electric impedance and the healing of diabetic foot ulcers
Authors: Gonzalez-Correa C A , Rivera-Garzón R A , Martínez-Táutiva S 
Published: September 2019

Abstract
Diabetic foot (DF) is a complication of people suffering from diabetes mellitus (DM) with an overall prevalence estimated as 6.3%. Healing of diabetic ulcers takes several weeks, and follow up is needed both to assess the improvement of the wound and to detect possible complications. Ulcer diameter, pH and temperature have been used for such purpose and some authors have also proposed the use of Electric Bioimpedance (EBI). The results presented in this paper are taken from a small pilot study carried out to evaluate the healing effect of high quality, unrefined, whole cane sugar (“panela”) in people with unilateral diabetic foot ulcers in one of the legs. 6 volunteers (3 male and 3 female, aged between 51 and 85 mean age 71) were treated either with Triticum vulgare or with “panela” and EBI measurements (resistance or R, reactance or Xc, and phase angle or θ at 50 kHz) on both legs were taken during a follow up period of 5 weeks. Although the healing process ran well with no complications, EBI parameters did not rise during the treatment, as expected. Differences between the ulcerated and the not-ulcerated legs seem to be present (higher values for R in the affected side and lower for Xc and θ), but it does not seem to be a trend of the former towards the values of the latter. EBI values of the sample with DM are much lower than those of a sample of the 8 healthy volunteers measured for this study.
Bioimpedance and bone fracture detection: A state of the art
Authors: Dell’Osa A H , Felice C J , Simini F 
Published: September 2019

Abstract
Bioimpedance measurements are used increasingly in health applications because bioelectric parameters have been associated with anatomical and physiological properties, thus enabling to distinguish medical conditions. For bone fracture diagnostics, nevertheless, there is no established non-invasive method. Ex vivo studies and In vivo bioimpedance procedures, both invasive and non-invasive, on mammalians long bones are associated with promising results. In this work, out of a total of 568 papers, we reviewd 59 articles that mention long bone integrity by electric properties, be it Bioimpedance Analysis, Electrical Impedance Spectroscopy or Electrical Impedance Tomography. The papers are described in three sections, “Ex vivo measurements”, “In vivo invasive measurements” and “In vivo non-invasive measurements”. This review allows to establish the basics to planning the development of new technology to detect bone fracture via bioimpedance measurements.
Rectal electrical bio-impedance spectroscopy in the detection of colorectal anomalies associated with cancer
Authors: González-Correa C A , Mulett-Vásquez E , Osorio-Chica M , Dussán-Lubert C , Miranda D 
Published: September 2019

Abstract
Colorectal cancer is the third most common cancer worldwide. Tests available for screening this cancer have low sensitivity or are challenging and costly to implement. Based on the concept of field cancerization, or carcinogenic field effect, the possibility of early detection of cancer by electrical bioimpedance spectroscopy measurements on the rectum was studied. For this research, seventy-seven subjects who attended the clinic for total colonoscopy were examined, and readings were taken at eight frequencies with an electrical bioimpedance spectroscopy probe. Four measurements were taken from the rectum of each subject, with the electrical probe being introduced into the rectum through an anoscope, before a total colonoscopy. An inverse model was used to obtain Cole-Cole parameters for each electrical bioimpedance spectra. Two results were the more prominent in this research; firstly, the field cancerization effect was observed and secondly, a significative correlation between rectal electrical bioimpedance and abnormalities associated with cancer was found (p-value = 0.002).