3,399 research outputs found

    Herd Behaviors in Financial Markets

    Full text link
    We investigate the herd behavior of returns for the yen-dollar exchange rate in the Japanese financial market. It is obtained that the probability distribution P(R)P(R) of returns RR satisfies the power-law behavior P(R)RβP(R) \simeq R^{-\beta} with the exponents β=3.11 \beta=3.11(the time interval τ=\tau= one minute) and 3.36(τ=\tau= one day). The informational cascade regime appears in the herding parameter H2.33H\ge 2.33 at τ=\tau= one minute, while it occurs no herding at τ=\tau= one day. Especially, we find that the distribution of normalized returns shows a crossover to a Gaussian distribution at one time step Δt=1\Delta t=1 day.Comment: 15 pages, 6 figure

    Scarred Resonances and Steady Probability Distribution in a Chaotic Microcavity

    Full text link
    We investigate scarred resonances of a stadium-shaped chaotic microcavity. It is shown that two components with different chirality of the scarring pattern are slightly rotated in opposite ways from the underlying unstable periodic orbit, when the incident angles of the scarring pattern are close to the critical angle for total internal reflection. In addition, the correspondence of emission pattern with the scarring pattern disappears when the incident angles are much larger than the critical angle. The steady probability distribution gives a consistent explanation about these interesting phenomena and makes it possible to expect the emission pattern in the latter case.Comment: 4 pages, 5 figure

    Two-dimensional imaging of edge-localized modes in KSTAR plasmas unperturbed and perturbed by n=1 external magnetic fields

    Get PDF
    The temporal evolution of edge-localized modes (ELMs) has been studied using a 2-D electron cyclotron emission imaging system in the KSTAR tokamak. The ELMs are observed to evolve in three distinctive stages: the initial linear growth of multiple filamentary structures having a net poloidal rotation, the interim state of regularly spaced saturated filaments, and the final crash through a short transient phase characterized by abrupt changes in the relative amplitudes and distance among filaments. The crash phase, typically consisted of multiple bursts of a single filament, involves a complex dynamics, poloidal elongation of the bursting filament, development of a fingerlike bulge, and fast localized burst through the finger. Substantial alterations of the ELM dynamics, such as mode number, poloidal rotation, and crash time scale, have been observed under external magnetic perturbations with the toroidal mode number n = 1. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3694842]X1125sciescopu

    Electronic structures of Zn1x_{1-x}Cox_xO using photoemission and x-ray absorption spectroscopy

    Full text link
    Electronic structures of Zn1x_{1-x}Cox_xO have been investigated using photoemission spectroscopy (PES) and x-ray absorption spectroscopy (XAS). The Co 3d states are found to lie near the top of the O 2p2p valence band, with a peak around 3\sim 3 eV binding energy. The Co 2p2p XAS spectrum provides evidence that the Co ions in Zn1x_{1-x}Cox_{x}O are in the divalent Co2+^{2+} (d7d^7) states under the tetrahedral symmetry. Our finding indicates that the properly substituted Co ions for Zn sites will not produce the diluted ferromagnetic semiconductor property.Comment: 3 pages, 2 figure

    Occlusion-Aware Depth Estimation with Adaptive Normal Constraints

    Get PDF
    We present a new learning-based method for multi-frame depth estimation from a color video, which is a fundamental problem in scene understanding, robot navigation or handheld 3D reconstruction. While recent learning-based methods estimate depth at high accuracy, 3D point clouds exported from their depth maps often fail to preserve important geometric feature (e.g., corners, edges, planes) of man-made scenes. Widely-used pixel-wise depth errors do not specifically penalize inconsistency on these features. These inaccuracies are particularly severe when subsequent depth reconstructions are accumulated in an attempt to scan a full environment with man-made objects with this kind of features. Our depth estimation algorithm therefore introduces a Combined Normal Map (CNM) constraint, which is designed to better preserve high-curvature features and global planar regions. In order to further improve the depth estimation accuracy, we introduce a new occlusion-aware strategy that aggregates initial depth predictions from multiple adjacent views into one final depth map and one occlusion probability map for the current reference view. Our method outperforms the state-of-the-art in terms of depth estimation accuracy, and preserves essential geometric features of man-made indoor scenes much better than other algorithms.Comment: ECCV 202

    Properties of Central Caustics in Planetary Microlensing

    Full text link
    To maximize the number of planet detections, current microlensing follow-up observations are focusing on high-magnification events which have a higher chance of being perturbed by central caustics. In this paper, we investigate the properties of central caustics and the perturbations induced by them. We derive analytic expressions of the location, size, and shape of the central caustic as a function of the star-planet separation, ss, and the planet/star mass ratio, qq, under the planetary perturbative approximation and compare the results with those based on numerical computations. While it has been known that the size of the planetary caustic is \propto \sqrt{q}, we find from this work that the dependence of the size of the central caustic on qq is linear, i.e., \propto q, implying that the central caustic shrinks much more rapidly with the decrease of qq compared to the planetary caustic. The central-caustic size depends also on the star-planet separation. If the size of the caustic is defined as the separation between the two cusps on the star-planet axis (horizontal width), we find that the dependence of the central-caustic size on the separation is \propto (s+1/s). While the size of the central caustic depends both on ss and q, its shape defined as the vertical/horizontal width ratio, R_c, is solely dependent on the planetary separation and we derive an analytic relation between R_c and s. Due to the smaller size of the central caustic combined with much more rapid decrease of its size with the decrease of q, the effect of finite source size on the perturbation induced by the central caustic is much more severe than the effect on the perturbation induced by the planetary caustic. Abridged.Comment: 5 pages, 4 figures, ApJ accepte

    Rhodium-oxide-coated indium tin oxide for enhancement of hole injection in organic light emitting diodes

    Get PDF
    The authors report the enhancement of hole injection using an RhOx layer between indium tin oxide anodes and 4, 4??? -bis[N-(1-naphtyl)- N -phenyl-amino]biphenyl in organic light-emitting diodes (OLEDs). The operation voltage of OLEDs at 700 cdm2 decreased from 13 to 10 V as the Rh layer changed to RhOx by surface treatment using O2 plasma. Synchrotron radiation photoelectron spectroscopy results showed that the work function increased by 0.2 eV as the Rh layer transformed into RhOx. Thus, the hole injection energy barrier was lowered, reducing the turn-on voltage and increasing the quantum efficiency of OLEDs.open281

    Immune-modulation of two BATF3 paralogues in rainbow trout Oncorhynchus mykiss 

    Get PDF
    This work was supported by the Royal Society of Edinburgh and the National Natural Science Foundation of China (Grant Nos., 31511130137 and 31372568). Dr Jun Wang’s visit to the Scottish Fish Immunology Research Centre was funded by the China Scholarship Council (CSC).Peer reviewedPostprin

    Traveltime calculations from frequency-domain downward-continuation algorithms

    Get PDF
    We present a new, fast 3D traveltime calculation algorithm that employs existing frequency-domain waveequation downward-continuation software. By modifying such software to solve for a few complex (rather than real) frequencies, we are able to calculate not only the first arrival and the approximately most energetic traveltimes at each depth point but also their corresponding amplitudes.We compute traveltimes by either taking the logarithm of displacements obtained by the oneway wave equation at a frequency or calculating derivatives of displacements numerically. Amplitudes are estimated from absolute value of the displacement at a frequency. By using the one-way downgoing wave equation, we also circumvent generating traveltimes corresponding to near-surface upcoming head waves not often needed in migration.We compare the traveltimes computed by our algorithm with those obtained by picking the most energetic arrivals from finite-difference solutions of the one-way wave equation, and show that our traveltime calculation method yields traveltimes comparable to solutions of the one-way wave equation. We illustrate the accuracy of our traveltime algorithm by migrating the 2D IFP Marmousi and the 3D SEG/EAGE salt models.This work was financially supported by National Laboratory Project of Ministry of Science and Technology, Brain Korea 21 project of theKorea Ministry of Education, and grant No. R03- 2000-000-00003-0 from the Basic Research Program of the Korea Science & Engineering Foundation
    corecore