bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simple and visually orientated approach for type synthesis of overconstrained 1T2R parallel mechanisms
Authors: Huang Tian , Dong Chenglin , Liu Haitao , Sun Tao , Chetwynd Derek G. 
Published: June 2018

SUMMARYThis paper presents a simple and highly visual approach for the type synthesis of a family of overconstrained parallel mechanisms that have one translational and two rotational movement capabilities. It considers, especially, mechanisms offering the accuracy and dynamic response needed for machining applications. This family features a spatial limb plus a member of a class of planar symmetrical linkages, the latter connected by a revolute joint either to the machine frame at its base link or to the platform at its output link. Criteria for selecting suitable structures from among numerous candidates are proposed by considering the realistic practical requirements for reconfigurability, movement capability, rational component design and so on. It concludes that a few can simultaneously fulfil the proposed criteria, even though a variety of structures have been presented in the literature. Exploitation of the proposed structures and evaluation criteria then leads to a novel five degrees of freedom hybrid module named TriMule. A significant potential advantage of the TriMule over the Tricept arises because all the joints connecting the base link and the machine frame can be integrated into one single, compact part, leading to a lightweight, cost effective and flexible design particularly suitable for configuring various robotized manufacturing cells.
Weighting-based semantic similarity measure based on topological parameters in semantic taxonomy
Authors: SAIF ABDULGABBAR , ZAINODIN UMMI ZAKIAH , OMAR NAZLIA , GHAREB ABDULLAH SAEED 
Published: June 2018

AbstractSemantic measures are used in handling different issues in several research areas, such as artificial intelligence, natural language processing, knowledge engineering, bioinformatics, and information retrieval. Hierarchical feature-based semantic measures have been proposed to estimate the semantic similarity between two concepts/words depending on the features extracted from a semantic taxonomy (hierarchy) of a given lexical source. The central issue in these measures is the constant weighting assumption that all elements in the semantic representation of the concept possess the same relevance. In this paper, a new weighting-based semantic similarity measure is proposed to address the issues in hierarchical feature-based measures. Four mechanisms are introduced to weigh the degree of relevance of features in the semantic representation of a concept by using topological parameters (edge, depth, descendants, and density) in a semantic taxonomy. With the semantic taxonomy of WordNet, the proposed semantic measure is evaluated for word semantic similarity in four gold-standard datasets. Experimental results show that the proposed measure outperforms hierarchical feature-based semantic measures in all the datasets. Comparison results also imply that the proposed measure is more effective than information-content measures in measuring semantic similarity.
A Novel Method to Reconstruct the Force Curve by Higher Harmonics of the First Two Flexural Modes in Frequency Modulation Atomic Force Microscope (FM-AFM)
Authors: Zhang Suoxin , Qian Jianqiang , Li Yingzi , Zhang Yingxu , Wang Zhenyu 
Published: June 2018

AbstractAtomic force microscope (AFM) is an idealized tool to measure the physical and chemical properties of the sample surfaces by reconstructing the force curve, which is of great significance to materials science, biology, and medicine science. Frequency modulation atomic force microscope (FM-AFM) collects the frequency shift as feedback thus having high force sensitivity and it accomplishes a true noncontact mode, which means great potential in biological sample detection field. However, it is a challenge to establish the relationship between the cantilever properties observed in practice and the tip–sample interaction theoretically. Moreover, there is no existing method to reconstruct the force curve in FM-AFM combining the higher harmonics and the higher flexural modes. This paper proposes a novel method that a full force curve can be reconstructed by any order higher harmonics of the first two flexural modes under any vibration amplitude in FM-AFM. Moreover, in the small amplitude regime, short range forces are reconstructed more accurately by higher harmonics analysis compared with fundamental harmonics using the Sader–Jarvis formula.
Domestic Devotion and the Georgian Church
Authors: Braddock Andrew 
Published: June 2018

AbstractThis article explores the development of domestic devotion in the Georgian Church of England through an examination of the manuals of prayer produced and circulated for both personal and family use throughout the eighteenth century. Alongside more well-known works, including Edmund Gibson’s Family Devotion and Robert Nelson’s Companion for the Festivals and Fasts, it pays attention to the diverse material provided for private and household devotion and its relationship to The Book of Common Prayer. The article highlights the key themes that were expressed through this literature, the spirituality that it fostered, and the sources on which it drew. It reveals how greater awareness of this material can deepen our understanding of how Georgian Anglicans prayed and what they were encouraged to pray for.
Fifty Years of Candidate Pulsar Selection - What next?
Authors: Lyon R. J. 
Published: June 2018

AbstractFor fifty years astronomers have been searching for pulsar signals in observational data. Throughout this time the process of choosing detections worthy of investigation, so called ‘candidate selection’, has been effective, yielding thousands of pulsar discoveries. Yet in recent years technological advances have permitted the proliferation of pulsar-like candidates, straining our candidate selection capabilities, and ultimately reducing selection accuracy. To overcome such problems, we now apply ‘intelligent’ machine learning tools. Whilst these have achieved success, candidate volumes continue to increase, and our methods have to evolve to keep pace with the change. This talk considers how to meet this challenge as a community.
Spectral Flattening of Crab Giant Pulses at Low Frequencies
Authors: Meyers Bradley W. , Tremblay Steven E. , Ramesh Bhat N. D. , Shannon Ryan M. 
Published: June 2018

AbstractThe frequency dependence of normal pulsar radio emission is typically observed to be a power law, with some indications of a flattening or turnover at low frequencies (≲ 100 MHz). The spectrum of the Crab pulsar’s giant pulse emission has not been examined as closely. We conducted simultaneous wideband observations of the Crab pulsar, with the Parkes radio telescope and the Murchison Widefield Array, to study the spectral behaviour of its giant pulses. Our analysis shows that the mean spectral index of Crab giant pulses flattens at low frequencies, from −2.6 ± 0.5 between the Parkes bands, to −0.7 ± 1.4 between the lowest MWA subbands.
Magnetar nebulae can be rotationally powered
Authors: Torres Diego F. 
Published: June 2018

AbstractA wind nebula generating extended X-ray emission was recently detected surrounding Swift 1834.9-0846. This is the first magnetar for which such a (pulsar) wind nebula (PWN) was found. I demonstrate that Swift 1834.9-0846’s nebula can be rotationally-powered if it is being compressed by the environment. The physical reason behind this is the dominance of adiabatic heating over all other cooling and escape processes. This effect can happen only for pulsars of relatively low spin-down power and can make for very efficient nebulae. This contribution is based on previous work published in ApJ 835, article id. 54, 13 pp. (2017).
Searching for X-ray Pulsations from Neutron Stars Using NICER
Authors: Ray Paul S. , Arzoumanian Zaven , Gendreau Keith C. ,   for the NICER Working Group on Pulsation Searches and Multiwavelength Coordination
Published: June 2018

AbstractThe Neutron Star Interior Composition Explorer (NICER) presents an exciting new capability for exploring the modulation properties of X-ray emitting neutron stars, including large area, low background, extremely precise absolute event time stamps, superb low-energy response and flexible scheduling. The Pulsation Searches and Multiwavelength Coordination working group has designed a 2.5 Ms observing program to search for emission and characterize the modulation properties of about 30 known or suspected neutron star sources across a number of source categories. A key early goal will be to search for pulsations from millisecond pulsars that might exhibit thermal pulsations from the surface suitable for pulse profile modeling to constrain the neutron star equation of state. In addition, we will search for pulsations from transitional millisecond pulsars, isolated neutron stars, low-mass X-ray binaries (LMXBs), accretion-powered millisecond pulsars, central compact objects and other sources. We present our science plan and initial results from the first months of the NICER mission, including the discovery of pulsations from the millisecond pulsar J1231–1411.
Coherent origin of peculiar polarization in radio pulsars
Authors: Dyks Jarosław 
Published: June 2018

AbstractThe observed polarization of radio pulsars involves several peculiar effects, such as comparable amount of orthogonal polarization modes (OPMs) which often bear the same handedness of circular polarisation V. In the average profiles of B1913+16 and B1933+16, orthogonal jumps of polarization angle (PA) are observed to occur at the maximum V, instead of V = 0. High levels of V are also observed in core components (eg. in B1237+25), where they are accompanied by strong distortions of PA from the rotating vector model. In weakly polarized emission, PA jumps by 45° are observed in B1919+21 and B0823+26. It is shown that all these peculiarities can be interpreted in a model which assumes coherent addition of waves in natural propagation modes.
Inhomogeneous Chiral and Coulomb Crystal in Neutron Stars
Authors: Yasutake Nobutoshi , Lee Tong-Gyu , Maruyama Toshiki , Tatsumi Toshitaka 
Published: June 2018

AbstractWe study the possibility of two types of inhomogeneous phases in core of neutron stars: one is the Coulomb crystal, which is known as quark-hadron pasta structures, and another one is chiral crystal. In the Coulomb crystal, the inhomogeneous phase appears as the result of the balance between the surface tension and the Coulomb interaction. In chiral crystal, we study the inhomogeneous chiral condensate, which has spatial modulation. In the simple model in 1+1 dimensions, this condensate has the same feature with the FFLO state, which is well known in the condensed matter physics.
Luminosity of synchrotron radiation from outer magnetosphere of pulsars
Authors: Kisaka Shota , Tanaka Shuta J. 
Published: June 2018

AbstractWe calculate the luminosity of the synchrotron radiation from the vicinity of the light cylinder. We find that even if the thermal emission from the entire surface is included as the seed photon, the γ-ray to X-ray flux ratio for young pulsars is significantly higher than the observations. For these pulsars, most of γ-ray photons may be absorbed in the magnetosphere.
Radio spectra of millisecond pulsars
Authors: Kondratiev Vladislav , Bilous Anna ,   LOFAR PWG
Published: June 2018

AbstractBoth the physics of the pulsar emission mechanism and free-free absorption in the intervening interstellar medium can be tested with the pulsar radio spectra. We have built on our previous work on describing LOFAR population of millisecond pulsars (MSPs; Kondratiev et al. 2016) and HBA census of slow pulsars (Bilous et al. 2016) and present the study of radio spectra of the MSPs with a special attention on the low-frequency turnover. Using LOFAR timing data allowed us to measure flux densities of many MSPs over time span of up to three years in the frequency range 110–188 MHz. This provided more reliable estimates of mean flux densities and spectra reducing the influence of refractive scintillation, ionosphere and other factors on a single flux measurement. Together with published data at other radio frequencies we constructed pulsars’ spectra and fitted them with single or broken power-laws. We discuss the obtained spectra and their fits, paying special attention to the low-frequency turnover, and compare broadband radio spectra of MSPs to those of normal pulsars.
Search for FRB and FRB-like single pulses in Parkes magnetar data
Authors: Burgay M. , Esposito P. , Israel G.L. , Rea N. , Possenti A. , Sarkissian J. 
Published: June 2018

AbstractWe present the results of a search for strong single radio pulses emitted by magnetars and for FRB signals in the fields of magnetars observed at the Parkes radio telescope within the NAPA project P626. Unsurprisingly, given the short total observing time, no extragalacic FRB signal was found up to a DM of 3000 pc/cm3. Two strong pulses dispersed at the DM of the known radio magnetar J1550–5418 where found, one occurring at the same time of an X-ray burst. This result is potentially interesting in the framework of magnetar models for FRBs.
Status of the Thai 40-m Radio Telescope
Authors: Jaroenjittichai Phrudth 
Published: June 2018

AbstractSince the first light of the 2.4-m Thai National Telescope in 2013, Thailand foresees another great leap forward in astronomy. A project known as “Radio Astronomy Network and Geodesy for Development” (RANGD) by National Astronomical Research Institute of Thailand (NARIT) has been approved for year 2017-2021. A 40-m radio telescope has been planned to operate up to 115-GHz observation with prime-focus capability for low frequency and phased array feed receivers. The telescope’s first light is expected in late 2019 with a cryogenics K-band and L-band receivers. RFI environment at the site has been investigated and shown to be at reasonable level. A 13-m VGOS telescope is also included for geodetic applications. Early single-dish science will focus on time domain observations, such as pulsars and transients, outbursts and variability of maser and AGN sources.
On the Radio Emitting Particles of the Crab Nebula: Stochastic Acceleration Model
Authors: Tanaka Shuta J. 
Published: June 2018

AbstractThe standard shock acceleration model of pulsar wind nebulae (PWNe) does not account for the hard spectrum in radio wavelengths. The origin of the radio-emitting particles is also important to determine the pair production efficiency in the pulsar magnetosphere. Here, we propose a possible resolution for the particle energy distribution in PWNe; the radio-emitting particles are not accelerated at the pulsar wind termination shock but are stochastically accelerated by turbulence inside PWNe. We upgrade our past one-zone spectral evolution model including the energy diffusion, i.e., the stochastic acceleration, and apply to the Crab Nebula. For a particle injection to the stochastic acceleration process, we consider the continuous injection from the supernova ejecta or the impulsive injection associated with supernova explosion. The observed broadband spectrum and the decay of the radio flux are reproduced by tuning the amount of the particle injected to the stochastic acceleration process. Our results imply that some unveiled mechanisms, such as back reaction to the turbulence, are required to make the energies of stochastically and shock accelerated particles comparable.
Systematic analysis about the polarization in thermal radiations of magnetars
Authors: Yatabe Akihiro , Yamada Shoichi 
Published: June 2018

AbstractWe calculated the polarization in soft X-ray emitted from magnetars, which are expected to be observed by the next-generation X-ray satellites. We consider possible conversions of photon’s polarization modes in the atmosphere and it cannot be ignored when the magnetic field is relatively weak B ≲ 1013G.
The LOFAR Tied-Array All-Sky Survey for Pulsars and Fast Transients
Authors: Tan C. M. ,   the LOTAAS Group
Published: June 2018

AbstractThe LOFAR Tied Array All-Sky Survey (LOTAAS) is an ongoing all northern sky survey for pulsars and transients. It is one of the first large scale pulsar surveys conducted at an observing frequency below 200 MHz. The unique set-up of the survey is the simultaneous formation of 222 beams for each survey pointing by coherently adding signals from the central 6 LOFAR stations. This represents the first SKA-like pulsar survey. As of 12 September 2017, the survey has completed 1456 pointings, more than two-thirds of the total. The survey has discovered 61 new pulsars via Fourier-based periodicity searches and a further 5 via single pulse searches. I present the survey approach and distinctive features including a discussion of an improved machine learning classifier used to identify the best candidates produced by the pipeline for further investigation. I present a summary of the discoveries so far including the first binary pulsar and the pulsar with the longest spin period of 23.5 s.
Pulsar Observations at the Ghana Radio Astronomy Observatory
Authors: Scragg T. W. , Stappers B. W. , Breton R. P. , Smith J. N. , Adomako D. , Asabere B. Duah , Chibueze J. O. , Cloete K. 
Published: June 2018

AbstractIn August 2017 a new radio telescope, the Ghana Radio Astronomy Observatory (GRAO), was officially inaugurated at Kuntunse, Ghana. The GRAO is a former satellite Earth station and now the first operational station in the African VLBI Network (AVN). The Jodrell Bank Centre for Astrophysics (JBCA), supported by the UK’s STFC/Newton Fund, has developed a new pulsar timing system (Hebe) for the GRAO. We present some aspects of the design of Hebe and an outline of the first pulsar detection at GRAO.
Pulsar Science with the SKA
Authors: Keane Evan F. 
Published: June 2018

AbstractThe Square Kilometre Array (SKA) will be sensitive enough to discover all of the pulsars in the Milky Way that are beamed towards Earth. Already in the initial deployment, SKA Phase 1, it will make significant advances in pulsar science. In these proceedings I briefly overview what the SKA is, and describe its pulsar search and timing capabilities.
1,000,000 Giant Pulses from the Crab Pulsar
Authors: Mickaliger Mitchell B. , Stappers Ben W. , Bassa Cees G. , Fletcher Aldus G. 
Published: June 2018

AbstractThe Crab pulsar was first detected soon after the discovery of pulsars, and has long been studied for its unique traits. One of these traits, giant pulses that can be upwards of 1000 times brighter than the average pulse, was key to the Crab’s initial detection. Giant pulses are only seen in a few pulsars, and their energy distributions distinguish them from normal pulsed emission. There have been many studies over a period of decades to measure the power-law slope of these energy distributions, which provide insight into the possible emission mechanism of these giant pulses.The 42-foot telescope at Jodrell Bank Observatory monitors the Crab pulsar on a daily basis. We have single-pulse data dating back to 2012, containing roughly 1,000,000 giant pulses, the largest sample of Crab giant pulses to date. This large set of giant pulses allows us to do a range of science, including pulse-width studies and in-depth studies of giant-pulse energy distributions. The latter are particularly interesting, as close inspection of the high-energy tail of the energy distribution allows us to investigate the detectability of extragalactic giant-pulsing pulsars. Also, by calculating rates from these energy distributions, we may be able to shed light on a possible link between Fast Radio Bursts and giant pulses.
Pulsar Searches with the SKA
Authors: Levin L. , Armour W. , Baffa C. , Barr E. , Cooper S. , Eatough R. , Ensor A. , Giani E. , Karastergiou A. , Karuppusamy R. , Keith M. , Kramer M. , Lyon R. , Mackintosh M. , Mickaliger M. , van Nieuwpoort R , Pearson M. , Prabu T. , Roy J. , Sinnen O. , Spitler L. , Spreeuw H. , Stappers B. W. , van Straten W. , Williams C. , Wang H. , Wiesner K. ,   the SKA TDT team
Published: June 2018

AbstractThe Square Kilometre Array will be an amazing instrument for pulsar astronomy. While the full SKA will be sensitive enough to detect all pulsars in the Galaxy visible from Earth, already with SKA1, pulsar searches will discover enough pulsars to increase the currently known population by a factor of four, no doubt including a range of amazing unknown sources. Real time processing is needed to deal with the 60 PB of pulsar search data collected per day, using a signal processing pipeline required to perform more than 10 POps. Here we present the suggested design of the pulsar search engine for the SKA and discuss challenges and solutions to the pulsar search venture.
The glitch activity of rotation-powered pulsars
Authors: Fuentes J. R. , Espinoza C. M. , Reisenegger A. 
Published: June 2018

AbstractA statistical study of the glitch population and the behavior of the glitch activity across the known population of neutron stars is presented. A constant ratio between the glitch activity and the spin-down rate $\dot{\nu }_{\rm {g}}$/|$\dot{\nu }$| = 0.010 ± 0.001 is consistent with the behavior of all rotation-powered pulsars and magnetars. This relation is dominated by large glitches (Δν ≳ 10 μ Hz), which occur at a rate directly proportional to |$\dot{\nu }$|. The only exception are the rotation-powered pulsars with the highest values of |$\dot{\nu }$|, such as the Crab pulsar and PSR B0540–69, which exhibit a much smaller glitch activity, intrinsically different from each other and from the rest of the population. This contribution is based on the work done by Fuentes et al. (2017) “The glitch activity of neutron stars”, accepted for publication in A&A.
On the patchiness of the individual pulse spectra at the very low radio frequencies
Authors: Song Xiaoxi , Kondratiev Vladislav , Bilous Anna 
Published: June 2018

AbstractWe have used sensitive LOw Frequency ARray (LOFAR) observations of PSR B0809+74 at 15–62 MHz to study the anomalously intensive pulses, first reported by Ulyanov et al. (2006) at 18–30 MHz. Similarly to Ulyanov et al., we found that the spectra of strong pulses consist of distinct bright patches. Moreover, these spectral patches were spotted to drift upwards in frequency over the course of several pulse sequences. We established that this drift is not pulsar-intrinsic, but is caused by the broadband ~20 second-long enhancements of recorded signal, which influenced the dispersed tracks of several pulses at once. We speculate on the cause of such enhancements (i.e. propagation or telescope-related) and the ramifications they bring to the single-pulse studies at the very low radio frequencies. Depending on the origin, the phenomenon may also affect the analysis of highly dispersed single pulses at higher radio frequencies, e.g. Fast Radio Bursts.
Equation of state and pulsar death line
Authors: Zhou Xia 
Published: June 2018

AbstractIn this proceeding, we are going to introduce our recent work about the dependence of pulsar death line on the equation of state (Zhou et al. 2017). The results show that the equation of state affects the location of the pulsar death line in the P-Ṗ diagram. We offer another point of view to understand the pulsar death line and multiple observational facts would help us to reveal the nature of pulsars.
Testing the Universality of Free Fall with the Triple System J0337+1715
Authors: Archibald A. M. , Gusinskaia N. V. , Hessels J. W. T. , Lorimer D. R. , Lynch R. S. , Ransom S. M. , Stairs I. H. 
Published: June 2018

AbstractThe millisecond pulsar PSR J0337+1715 is in a mildly relativistic hierarchical triple system with two white dwarfs. This offers the possibility of testing the universality of free fall: does the neutron star fall with the same acceleration as the inner white dwarf in the gravity of the outer white dwarf? We have carried out an intensive pulsar timing campaign, yielding some 27000 pulse time-of-arrival (TOA) measurements with a median uncertainty of 1.2 μs. Here we describe our analysis procedure and timing model.