bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time-of-flight (TOF) implementation for PET reconstruction in practice
Authors: Filipović Marina , Comtat Claude , Stute Simon 
Published: October 2019

Abstract
The time-of-flight (TOF) feature of PET scanners has been used for a long time in PET reconstruction, but many implementational aspects are still incomplete or ambiguous in the literature. Here we formalize and present theoretical and practical implementation details for the reconstruction of clinical TOF histogram and list-mode data using ML-EM. Relevant aspects include the computation of the TOF component of the system matrix, the processing of TOF bins, the use of estimations of random and scattered coincidences, and differences between histogram and list-mode ML-EM TOF reconstruction. Several approaches and approximations have been implemented in the CASToR platform and compared for OSEM reconstructions of patient data from the GE Signa PET/MR scanner. Differences between implementations are not larger than the typical bias in clinical data reconstruction. The largest difference and contrast loss occur when the processing of histogram TOF bins is simplified, and list-mode reconstruction is most sensitive to the truncation of the Gaussian TOF probability distribution.
Gouy and spatial-curvature-induced phase shifts of light in two-dimensional curved space
Authors: Xu Chenni , Wang Li-Gang 
Published: October 2019

Abstract
Gouy phase is the axial phase anomaly of converging light waves discovered over one century ago, and is so far widely studied in various systems. In this work, we have theoretically calculated Gouy phase of light beams in both paraxial and nonparaxial regime on two-dimensional curved surface by generalizing angular spectrum method. We find that curvature of surface will also introduce an extra phase shift, which is named as spatial curvature-induced (SCI) phase. The behaviors of both phase shifts are illustrated on two typical surfaces of revolution, circular truncated cone and spherical surface. Gouy phase evolves slower on surface with greater spatial curvature on circular truncated cone, which is however opposite on spherical surface, while SCI phase evolves faster with curvature on both surfaces. On circular truncated cone, both phase shifts approach to a limit value along propagation, which does not happen on spherical surface due to the existence of singularity on the pole. An interpretation is presented to explain this peculiar phenomenon. Finally we also provide the analytical expression of paraxial Gaussian beam on general SORs. By comparing the result with the exact method we find the analytical expression is valid under the approximation that beam waist and scale of surface are beyond order of wavelength. We expect this work will enhance the comprehension about the behavior of electromagnetic wave in curved space, and further contribute to the study of general relativity phenomena in laboratory.
All-acoustic signal modulation and logic operation via defect induced cavity effects in phononic crystal coupled-resonator acoustic waveguides
Authors: Reyes Delfino , Walker Ezekiel , Zubov Yurii , Heo Hyeonu , Krokhin Arkadii , Neogi Arup 
Published: October 2019

AbstractA coupled resonant acoustic waveguide (CRAW) in a phononic crystal (PnC) was engineered to manipulate the propagation of ultrasonic waves within a conventional phononic bandgap for wavelength division multiplexing. The PnC device included two, forked, distinct CRAW waveguide channels that exhibited strong frequency and mode selectivity. Each branch was composed of cavities of differing volumes, with each giving rise to deep and shallow ‘impurity’ states. These states were utilized to select frequency windows where transmission along the channels was suppressed distinctly for each channel. Though completely a linear system, the mode sensitivity of each CRAW waveguide channel produced apparent nonlinear power dependence along each branch. Nonlinearity in the system arises from the combination of the mode sensitivity of each CRAW channel and small variations in the shape of the incident wavefront as a function of input power. The all-acoustic effect was then leveraged to realize an ultrasonic, spatial signal modulator, and logic element operating at 398 and 450 kHz using input power.
Polarization-based branch selection of bound states in the continuum in dielectric waveguide modes anti-crossed by a metal grating
Authors: Kikkawa R , Nishida M , Kadoya Y 
Published: October 2019

Abstract
We investigate bound states in the continuum (BICs) in a planar dielectric waveguide structure consisting of a gold grating on a dielectric layer with a back layer of metal. In this structure, Friedrich–Wintgen (FW) BICs caused by the destructive interference between the radiations from two waveguide modes appear near the anti-crossing point of the dispersion curves. In this study, it is revealed that the branch at which the BIC appears changes according to the polarization of the modes. Based on a temporal coupled mode theory, it is shown that the BIC branch is determined by the sign of the product of the coupling coefficients between the two waveguide modes and external radiation, which is consistent with FW theory. The signs of the coupling coefficients are estimated by the waveguide-mode decomposition of the numerically obtained electric fields and are confirmed to vary depending on the polarization.
A PCA approach to stellar abundances I. testing of the method validity
Authors: He Wei , Zhao Gang 
Published: October 2019

Abstract
The derivation of element abundances of stars is a key step in detailed spectroscopic analysis. A spectroscopic method may suffer from errors associated with model simplifications. We have developed a new method of deriving the various element abundances of stars based on the calibration established from a group of standard stars. We perform principal component analysis (PCA) on a homogeneous library of stellar spectra, and then use machine learning to calibrate the relationship between principal components and element abundances. By testing with spectral libraries S4N and MILES, we find that our procedure provides good consistency when spectra from a homogeneous set of observations are used, and it could be expanded to stars with quite a wide range of stellar parameters, with both dwarfs and giants. Moreover, we discuss the four key factors that have a significant impact on the results of derived element abundances, including the resolution of the spectra, wavelength range, the signal-to-noise ratio (S/N) of spectra and the number of principal components adopted.
Simultaneous optical g, r, i monitoring and IDV periodic analysis for quasar 3C 454.3
Authors: Fan Jun-Hui , Yuan Yu-Hai , Wu Hong , Wang Feng , Tao Jun , Gu Min-Feng 
Published: October 2019

Abstract
With the 1.26 m National Astronomical Observatory-Guangzhou University Infrared/Optical Telescope (NAGIOT) at Xinglong Station of National Astronomical Observatories, Chinese Academy of Sciences, we obtained 419 groups of simultaneous observations at g, r and i bands, for the first time, targeting quasar 3C 454.3 during 15 nights from 2016 October 23 to 2016 December 15. Based on our observations, we investigate the optical variabilities, the relation between brightness and color index, and the periodicity variability. The presented analyses demonstrate that: 1. The maximum variations at the g, r and i bands are Δ m

g|max = 1.015 ± 0.042 mag, Δ m

r|max = 1.188 ± 0.050 mag and Δ m

i|max = 1.305 ± 0.057 mag respectively. 2. During our 15 night monitoring program, intra-day variability was detected on one night (Nov. 2). Also, the brightness increased by A = 15.86% over 50.8 min, then decreased by A = 22.42% over 40.1 min. After a small bright state, its brightness increased again by 18.1% over 55 min at the g band. Similar phenomena happened at r and i bands. The intra-day variabilities at the three bands on 2016 November 2 indicate a period of 105 min, which implies a black hole mass of M
BH = (0.3 ∼ 1.85) × 109
M
⊙. 3. There is an anti-correlation between color index and magnitude, suggesting the source becomes redder when it brightens.
Low-mass and high-mass supermassive black holes in radio-loud AGNs are spun-up in different evolution paths
Authors: Wang Jing , Kong Min-Zhi , Liu Shun-Fang , Xu Da-Wei , Zhang Qiang , Wei Jian-Yan 
Published: October 2019

Abstract
How supermassive black holes (SMBHs) are spun-up is a key issue in modern astrophysics. As an extension to the study in Wang et al., here we address the issue by comparing the host galaxy properties of nearby (z < 0.05) radio-selected Seyfert 2 galaxies. With the two-dimensional bulge+disk decompositions for the SDSS r-band images, we identify a dichotomy in various host galaxy properties for radio-loud SMBHs. By assuming that radio emission from the jet reflects a high SMBH spin, which stems from the well-known Blandford-Znajek mechanism of jet production, high-mass SMBHs (i.e., M
BH > 107.9
M
⊙) have a preference for being spun-up in classical bulges, and low-mass SMBHs (i.e., M
BH = 106 − 107
M
⊙) in pseudo-bulges. This dichotomy suggests and confirms that high-mass and low-mass SMBHs are spun-up in different ways, i.e., a major “dry” merger and a secular evolution respectively.
Meta-analysis of electron cyclotron resonance absorption features detected in high-mass X-ray binaries
Authors: Christodoulou Dimitris M. , Laycock Silas G. T. , Kazanas Demosthenes 
Published: October 2019

Abstract
Using recent compilations of detailed X-ray observations and spectral models of exceptional quality, we record the electron cyclotron resonance absorption (ECRA) features that have been detected in 45 pulsating high-mass X-ray binaries (HMXBs) and ultraluminous X-ray (ULX) sources harboring neutron stars, although seven of these detections are still questionable and another 21 are single and/or not independently confirmed. From the comprehensive catalogs of Jaisawal & Naik and Staubert et al. and from several additional recent observations, we produce two lists of HMXB ECRA sources: a list of 17 sources in which multiple ECRA lines or single very low-energy lines are seen, in which we can reasonably assume that the lowest energy reveals the fundamental cyclotron level for each source; and a “contaminated” list of 38 sources including the 21 detections of single ECRA lines that may (not) be higher-level harmonics. Both lists confirm a previous result that we have obtained independently by modeling the propeller lines of Magellanic HMXB pulsars: the surface dipolar magnetic fields B
* of HMXB neutron stars are segregated around five distinct values with B
* = 0.28 ± 0.08, 0.55 ± 0.11, 1.3 ± 0.37, 3.0 ± 0.68 and 7.9 ± 3.1, in units of TG. However, an explanation of this phenomenon is currently lacking. We have found no correlation between these B
* values and the corresponding observed spin periods, spin period derivatives, orbital periods, maximum X-ray luminosities, neutron star masses or companion star masses.
Photometric investigations on two totally eclipsing contact binaries: V342 UMa and V509 Cam
Authors: Li Kai , Xia Qi-Qi , Liu Jin-Zhong , Zhang Yu , Gao Xing , Hu Shao-Ming , Guo Di-Fu , Chen Xu , Liu Yuan 
Published: October 2019

Abstract
By analyzing two sets of complete BVRcIc
light curves for V342 UMa and three sets of complete BVRcIc
light curves for V509 Cam, we determined that the two systems are both W-subtype contact binaries and that V342 UMa manifests a shallow contact configuration, while V509 Cam exhibits a medium contact configuration. Given that both of them are totally eclipsing binaries, the physical parameters derived only by the photometric light curves are reliable. Meanwhile, the period changes of the two targets were analyzed based on all available eclipsing times. We discovered that V342 UMa shows long-term period decrease with a rate of −1.02(± 0.54) × 10−7 d yr−1 and that V509 Cam displays long-term period increase with a rate of 3.96(± 0.90) × 10−8 d yr−1. Both the conservative mass transfer and angular momentum loss via magnetic stellar winds can be used to interpret the long-term period decrease of V342 UMa. The long-term period increase of V509 Cam can be explained by mass transfer from the less massive star to the more massive one. The absolute parameters of the two binaries were estimated according to their Gaia distances and our derived photometric solution results. This method can be extended to other contact binaries without radial velocities but with reliable photometric solutions. Their evolutionary states were investigated and we found that they reveal properties that are identical to other W-subtype contact systems.
Infrared photometric properties of inner and outer parts of HII regions
Authors: Topchieva Anastasiia , Akimkin Vitaly , Smirnov-Pinchukov Grigorii 
Published: October 2019

Abstract
The fact that infrared ring nebulae (IRRNe) are frequently associated with HII regions provides us with an opportunity to study dust at the interface between ionized and neutral gas. In this paper, we analyze the associated infrared (IR) radiation in the range from 8 to 500 μm in the outer and inner parts of 32 IRRNe showing a round shape. We aim to determine the morphology of these objects and possible dust evolution processes based on comparing IR radiation towards the ionized and neutral regions. We calculate six slopes between adjacent wavelengths in their spectral energy distributions to trace the difference in physical conditions inside and outside the ionized regions. Using data on these 32 objects, we demonstrate that their morphology is likely 3D spherical rather than 2D plane-like. The slope between 70 and 160 μm is the most appropriate tracer of dust temperature in the outer envelope. The larger 8-to-24 μm intensity ratio is associated with smaller intensities at mid-IR, indicating that {polycyclic aromatic hydrocarbons (PAHs) may indeed be generated due to larger grain destruction. These data are important for the subsequent theoretical modeling, and determining the dust evolution in HII regions and their envelopes.
The abundance of massive compact galaxies at 1.0 < z < 3.0 in 3D-HST/CANDELS
Authors: Lu Shi-Ying , Gu Yi-Zhou , Fang Guan-Wen , Yuan Qi-Rong 
Published: October 2019

Abstract
Based on a large sample of massive (M
* ⩾ 1010
M
⊙) compact galaxies at 1.0 < z < 3.0 in five 3D-HST/CANDELS fields, we quantify the fractional abundance and comoving number density of massive compact galaxies as a function of redshift. The samples of compact quiescent galaxies (cQGs) and compact star-forming galaxies (cSFGs) are constructed by various selection criteria of compact galaxies in the literature, and the effect of compactness definition on abundance estimate has proven to be remarkable, particularly for the cQGs and cSFGs at high redshifts. Regardless of the compactness criteria adopted, their overall redshift evolutions of fractional abundance and number density are found to be rather similar. Large samples of the cQGs exhibit a sustained increase in number density from z ∼ 3 to 2 and a plateau at 1 < z < 2. For massive cSFGs, a plateau in the number density at 2 < z < 3 can be found, as well as a continuous drop from z ∼ 2 to 1. The evolutionary trends of the cQG and cSFG abundances support the scenario that the cSFGs at z ≳ 2 may have been rapidly quenched into quiescent phase via violent dissipational processes, such as major merger and disk instabilities. The rarity of the cSFGs at lower redshifts (z < 1) can be interpreted by the decrease of gas reservoirs in dark matter halos and the consequent low efficiency of gas-rich dissipation.
GABE: Galaxy Assembly with Binary Evolution
Authors: Jiang Zhen , Wang Jie , Gao Liang , Zhang Feng-Hui , Guo Qi , Wang Lan , Pan Jun 
Published: October 2019

Abstract
We developed a new semi-analytic galaxy formation model: Galaxy Assembly with Binary Evolution (GABE). For the first time, we introduce binary evolution into semi-analytic models of galaxy formation by using the Yunnan-II stellar population synthesis model, which includes various binary interactions. When implementing our galaxy formation model onto the merger trees extracted from the Millennium simulation, it can reproduce a large body of observational results. We find that in the local universe, the model including binary evolution reduces the luminosity at optical and infrared wavelengths slightly, but it increases the luminosity at ultraviolet wavelengths significantly, especially in F
UV band. The resulting luminosity function does not change very much over SDSS optical bands and infrared band, but the predicted colors are bluer, especially when the F
UV band is under consideration. The new model allows us to explore the physics of various high energy events related to the remnants of binary stars, such as type Ia supernovae, short gamma-ray bursts and gravitational wave events, and their relation with host galaxies in a cosmological context.
Effect of Ginsenosides on Prevention of Alzheimer’s Disease
Authors: Zheng Yi , Gao Xiujun , Chen Qiqi , Yan Peisheng , Liu Rundong , Liang Hao , Zhang Mingchen 
Published: October 2019

Abstract
Alzheimer’s disease (AD), as a neurodegenerative disease that conceals the progressive development of early disease, has a long onset time and complicated etiology. As the number of Alzheimer’s patients increases year by year, it is a hot issue that looking for effective drug prevention and treatment. As the king of Chinese herbal medicine, ginseng contains a variety of pharmacologically active substances, especially ginsenosides can affect multiple metabolic pathways in the body, and its efficacy is relatively complicated. This article reviews the pathogenesis of AD and the preventive effects of five ginsenosides such as Rg1, Rb1, Rg2, Rg5 and Rh1 on AD, in order to provide a basis for the development of functional foods for preventing AD.
Demand side EMS using artificial neural network-based LP method
Authors: Loganathan N , Mayurappriyan P S , Lakshmi K 
Published: October 2019

Abstract
This proposed system introduces advancement technique towards the interest sideways Energy Managing Structure (EMS) of a given concerning hourly power costs. This proposed system studies a bunch of interrelated cost receptive requests popular an educational institution. This requests canister stand provided concluded the fundamental framework as well as stochastic different power sources (for example, wind power plant & sun-based energy sources. What’s more, the gathering of requests possesses a vitality storeroom. The proposed energy managing structure has a limit that every shopper can utilize their individual procedure to direct the current demand and costs trendy the energy dissemination framework. Towards tackle this energy managing structure issue then advancement calculation dependent on Linear Programming (LP) method takes remained executed. Notwithstanding LP calculation an ANN remained connected towards foresee the upcoming energy utilization the bunch of cost receptive requests. Main objective of the planned strategy remains toward boost the usage group of requests after it remains exposed towards an arrangement the compels. In this linear programming calculation enables bunch the interest to purchase, store and pitch vitality at reasonable occasions to change the hourly demand equal. Towards assess execution of this projected calculation of IEEE 14 transport framework remained measured. This outcome demonstrates the bunch of requests to vitality administration framework utilizing the proposed methodology expanding the effectiveness and limiting the misfortunes than the current strategies.
Dual Mode Operation of 8/6 SRM with Optimum Angle Operation in Hybrid Electric Vehicles using FLC based Controller
Authors: Radhakrishnan G 
Published: October 2019

Abstract
An optimum operating period of an 8/6 Switched Reluctance Motor (SRM) based on different load condition is analysed in this paper. The system is designed to analyse the speed control of machine in motoring mode and voltage control mode is carried out in this paper. Dual Mode switched reluctance motor is tested with the fuzzy logic controller, Mamdani method is used in fuzzy based system. In this paper the main objective is to concentrate on modelling the machine to maximise the average torque with minimum torque ripple in the optimised operating region with different loading conditions in dual mode region. This method also found to have increased efficiency, with the closed loop controlling action the system is robust and simple in construction. The optimised designed system has less manufacturing cost due to simple construction. The simulation is carried out using MATLAB/Simulink.
Review and comparative analysis on dc-dc converters used in electric vehicle applications
Authors: Jagadeesh Ingilala , Indragandhi V. 
Published: October 2019

AbstractThis paper is reported with different kinds of DC-DC converters such as sepic, boost and bidirectional converters. Integrating the boost, sepic, bidirectional DC-DC converters enables to identify the suitable converter for renewable energy applications with accurate power rating. The performance of non-isolated converter is assessed on the basis of these review. The solar PV conversion efficiency is low, so the converter is used to step-up/step down the voltage levels. This paper attempts to perform by examing efficiency of DC-DC converters and the voltage and current stress on the switches. A detailed review is carried out on basic PV and fuel cell based electric vehicles.
Current control techniques of single phase shunt active power filter- a review
Authors: Kanagavel Rameshkumar , Indragandhi V 
Published: October 2019

Abstract
This manuscript gives a complete survey on current control for single phase Shunt Active Power Filter (SAPF). Various current control techniques like linear current control, Hysteresis, Model Predictive Current Control (MPCC) and other techniques are discussed. The primary advantages and disadvantages of current controllers in SAPF have been presented in a table. This manuscript offers a suitable reference for forthcoming work in power quality applications and its associated research.
Disturbance Analysis and Implementation of High Voltage Gain Non-Isolated DC-DC Converter for Renewable Applications
Authors: Arunkumari T , Indragandhi V , Sidhu Vikramjeet Singh , Udayanga Hemapala K T M 
Published: October 2019

Abstract
A modified high gain single switch high-voltage converter is presented in this paper. The proposed converter is a blend of a voltage tripler and a SEPIC-boost mode converter. Its operational modes are presented in detail. This converter has advantages that include a single switch, reduced component stress and size, and reduced ripple output voltage and input ripple current. The simulation results of the suggested converter and a conventional multilevel SEPIC converter are presented. The prototype of a 30 V to 400 V input, 400 W output is developed and the performance of the designed topology is evaluated. The theoretical and experimental results conclude that this converter is suitable for high-voltage applications.
Solar powered air conditioner using BLDC motor
Authors: Nazar Ali A , Sivamani D , Jaiganesh R , Pradeep M 
Published: October 2019

Abstract
This paper present a load compressor fed Brushless DC motor for solar power air conditioner under variable air conditions. At current scenario, air conditioners are manufactured according to room size and space with available of objects present in the room.The output of the air conditioner cannot be alternatively changed. This problem is overcome by modify the fixed output of the air conditioner using BLDC motor. The BLDC motor performance is superior when compared to other motor. Solar power is used as the main source which is a renewable energy and readily available and also very useful for the future generation. This work deals with the output of the air conditioner can be alternatively changed according to the size of the room by varying the speed of Brushless DC motor.