568 research outputs found
Alternation of the flickering morphology between the high and low state in MV Lyr
AIMS: We studied unique data of a nova-like system MV Lyr during transition
from the high to low state and vice versa taken by the Kepler space telescope.
We were interested in evolution of frequency components found previously by
Scaringi et al. in different data also obtained by Kepler. METHODS: We divided
the light curve into 10 day segments and investigated the corresponding power
density spectra. We searched for individual frequency components by fitting
with Lorentzian functions. Additionally, we investigated the variability using
averaged shot profiles calculated from the light curve divided into 10 equally
spaces subsamples. RESULTS: We found very complex changes of the power density
spectra. We focused our study onto three frequency components. Strong activity
increase is seen at low frequencies. Contrariwise, the high frequency part of
the spectrum strongly decreases in power with specific rise in characteristic
frequencies of the individual components. We discuss various scenarios of this
phenomenology as reprocessing of X-rays in a receding accretion disc or a
radiation from a more active region at the outer disc. Finally, we show that
various cataclysmic variables show similar characteristic frequencies in their
power density spectra. These are dependent on activity stage, making the
situation similar to X-ray binaries.Comment: accepted for publication to A&
Pengaruh Peluang Pertumbuhan dan Ketidakpastian Lingkungan terhadap Tindakan Manajemen Laba
Effect of Growth Opportunities and Environmental Uncertainties To Profit ManagementThe purpose of this study is to investigate the determinant of firm's earning management by food and beverage industry in Indonesian Stock Exchange (IDX) during 2010-2015. The impact growth opportunity and environmental uncertainty may induce greater manager's use discretionary accruals as earning management. Furthermore, this study also examines the effect auditor quality on the relationship between growth opportunity and earning management. Using purposive sampling, the sample of this study consist 8 companies are listed on IDX (48 firms-year). The result indicated that firm's situation under growth opportunity and environmental uncertainty had an impact on the earning management. However, auditor quality proven has an impact on the relationship between growth opportunity and eaning management.DOI: 10.15408/ess.v6i2.357
Scalable Spin Amplification with a Gain over a Hundred
We propose a scalable and practical implementation of spin amplification
which does not require individual addressing nor a specially tailored spin
network. We have demonstrated a gain of 140 in a solid-state nuclear spin
system of which the spin polarization has been increased to 0.12 using dynamic
nuclear polarization with photoexcited triplet electron spins. Spin
amplification scalable to a higher gain opens the door to the single spin
measurement for a readout of quantum computers as well as practical
applications of nuclear magnetic resonance (NMR) spectroscopy to infinitesimal
samples which have been concealed by thermal noise.Comment: 6 pages, 7 figure
Swift Observations of MAXI J1659-152: A Compact Binary with a Black Hole Accretor
We report on the detection and follow-up high cadence monitoring observations
of MAXI J1659-152, a bright Galactic X-ray binary transient with a likely
black-hole accretor, by Swift over a 27 day period after its initial outburst
detection. MAXI J1659-152 was discovered almost simultaneously by Swift and
MAXI on 2010 Sept 25, and was monitored intensively from the early stages of
the outburst through the rise to a brightness of ~0.5 Crab by the Swift XRT,
UVOT, and BAT. We present temporal and spectral analysis of the Swift
observations. The broadband light-curves show variability characteristic of
black-hole candidate transients. We present the evolution of thermal and
non-thermal components of the 0.5-150 keV combined X-ray spectra during the
outburst. MAXI J1659-152 displays accretion state changes typically associated
with black-hole binaries, transitioning from its initial detection in the Hard
State, to the Steep Power-Law State, followed by a slow evolution towards the
Thermal State, signified by an increasingly dominant thermal component
associated with the accretion disk, although this state change did not complete
before Swift observations ended. We observe an anti-correlation between the
increasing temperature and decreasing radius of the inner edge of the accretion
disk, suggesting that the inner edge of the accretion disk in-falls towards the
black-hole as the disk temperature increases. We observed significant evolution
in the absorption column during the initial rise of the outburst, with the
absorption almost doubling, suggestive of the presence of an evolving wind from
the accretion disk. We detect quasi- periodic oscillations that evolve with the
outburst, as well as irregular shaped dips that recur with a period of
2.42\pm0.09 hours, strongly suggesting an orbital period that would make MAXI
J1659-152 the shortest period black-hole binary yet known.Comment: Accepted for publication in ApJ. 9 pages, 7 figure
X-Ray Fluctuations from Locally Unstable Advection-Dominated Disks
The response of advection-dominated accretion disks to local disturbances is
examined by one-dimensional numerical simulations. It is generally believed
that advection-dominated disks are thermally stable. We, however, find that any
disurbance added onto accretion flow at large radii does not decay so rapidly
that it can move inward with roughly the free-fall velocity. Although
disturbances continue to be present, the global disk structure will not be
modified largely. This can account for persistent hard X-ray emission with
substantial variations observed in active galactic nuclei and stellar black
hole candidates during the hard state. Moreover, when the disturbance reaches
the innermost parts, an acoustic wave emerges, propagating outward as a shock
wave. The resultant light variation is roughly (time) symmetric and is quite
reminiscent of the observed X-ray shots of Cygnus X-1.Comment: plain TeX, 11 pages, without figures; to be published in ApJ Lette
THE RELATIONSHIP OF BRAND COMMUNICATION, BRAND IMAGE, AND BRAND TRUST TO BRAND LOYALTY OF SAMSUNG CELLULAR PHONE PRODUCT
Each people have a trust to the product that they use for daily activity, such as a cellular phone which almost all people are using this product for communicating tool to each other. But not just only for communication purpose, each cellular phone is used by the user for entertaining purpose. Talking about cellular phone, Samsung is one of the most cellular phones that famous in Indonesia, we can see this product everywhere, and many people are using Samsung product, starting from the cheapest one to the most expensive prices, and its users from school age to workers level. As a product, Samsung is one of the famous brands which successful to attract its users and any potential user to use the product. The level of people trust to this product is higher than other products. The trust itself is not coming too easy, Samsung has to convince the customers or potential customers of what benefit that they will get by using Samsung product, and also the fixed product reputation will be able to attract customers’ attention. This research aims to find out the relationship of brand communication, brand image, and brand trust that influences brand loyalty. This research itself is using a statistical the modeling structural equations. The sampling method that applied by the researcher is a random sampling to 130 users (students, workers) of Samsung cellular phone (any types, and prices) in Jakarta, Surabaya, and Tangerang City. The results showed that brand communication influences brand image, brand communication influences brand trust, brand image has an effect on brand trust, and brand trust has an influence on brand loyalty of the Samsung customers
Combined Spectral and Timing Analysis of the Black Hole Candidate MAXI J1659-152 Discovered by MAXI and Swift
We report on X-ray spectral and timing results of the new black hole
candidate (BHC) MAXI J1659-152 with the orbital period of 2.41 hours (shortest
among BHCs) in the 2010 outburst from 65 Rossi X-ray Timing Explorer (RXTE)
observations and 8 simultaneous Swift and RXTE observations. According to the
definitions of the spectral states in Remillard & McClintock (2006), most of
the observations have been classified into the intermediate state. All the
X-ray broadband spectra can be modeled by a multi-color disk plus a power-law
with an exponential cutoff or a multi-color disk plus a Comptonization
component. During the initial phase of the outburst, a high energy cutoff was
visible at 30-40 keV. The innermost radius of the disk gradually decreased by a
factor of more than 3 from the onset of the outburst and reached a constant
value of 35 d_10 cos i^-1/2 km, where d_10 is the distance in units of 10 kpc
and is the inclination. The type-C quasi-periodic oscillation (QPO)
frequency varied from 1.6 Hz to 7.3 Hz in association with a change of the
innermost radius, while the innermost radius remained constant during the
type-B QPO detections at 1.6-4.1 Hz. Hence, we suggest that the origin of the
type-B QPOs is different from that of type-C QPOs, the latter of which would
originate from the disk truncation radius. Assuming the constant innermost
radius in the latter phase of the outburst as the innermost stable circular
orbit, the black hole mass in MAXI J1659-152 is estimated to be 3.6-8.0 M_solar
for a distance of 5.3-8.6 kpc and an inclination angle of 60-75 degrees.Comment: 27 pages, 14 figures, accepted for publication in PAS
H2-decoupling-accelerated H1 spin diffusion in dynamic nuclear polarization with photoexcited triplet electrons
In dynamic nuclear polarization (DNP) experiments applied to organic solids for creating nonequilibrium, high H1 spin polarization, an efficient buildup of H1 polarization is attained by partially deuterating the material of interest with an appropriate H1 concentration. In such a dilute H1 spin system, it is shown that the H1 spin diffusion rate and thereby the buildup efficiency of H1 polarization can further be enhanced by continually applying radiofrequency irradiation for deuterium decoupling during the DNP process. As experimentally confirmed in this work, the electron spin polarization of the photoexcited triplet state is mainly transferred only to those H1 spins, which are in the vicinity of the electron spins, and H1 spin diffusion transports the localized H1 polarization over the whole sample volume. The H1 spin diffusion coefficients are estimated from DNP repetition interval dependence of the initial buildup rate of H1 polarization, and the result indicates that the spin diffusion coefficient is enhanced by a factor of 2 compared to that without H2 decoupling.This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in M. Negoro, K. Nakayama, K. Tateishi, A. Kagawa, K. Takeda, and M. Kitagawa, J. Chem. Phys. 133, 154504 (2010) and may be found at https://doi.org/10.1063/1.3493453
The X-ray CCD camera of the MAXI Experiment on the ISS/JEM
MAXI, Monitor of All-sky X-ray Image, is the X-ray observatory on the
Japanese experimental module (JEM) Exposed Facility (EF) on the International
Space Station (ISS). MAXI is a slit scanning camera which consists of two kinds
of X-ray detectors: one is a one-dimensional position-sensitive proportional
counter with a total area of , the Gas Slit Camera (GSC), and
the other is an X-ray CCD array with a total area , the
Solid-state Slit Camera (SSC). The GSC subtends a field of view with an angular
dimension of 1 while the SSC subtends a field of view
with an angular dimension of 1 times a little less than 180. In
the course of one station orbit, MAXI can scan almost the entire sky with a
precision of 1 and with an X-ray energy range of 0.5-30 keV. We have
developed the engineering model of CCD chips and the analogue electronics for
the SSC. The energy resolution of EM CCD for Mn K has a full-width at
half maximum of 182 eV. Readout noise is 11 e^- rms.Comment: 10 pages, 4 figures Accepted for Nuclear Instruments and Method in
Physics Researc
- …