Инсайдерская торговля и модели информированной торговли

This paper aims to examine how corporate insider trading influences trading patterns of foreign and institutional investors especially in firms with high discretionary accruals and low book-to-market ratios as proxies for information uncertainty. This study uses methods such as trading patterns of informed traders who are considered to gather more precise information before and after insider trading and tests how insider trading affects informed traders. The results of this study provide evidence that insider trading is likely to influence informed traders’ trading patterns. After controlling for firm-specific factors, this study finds that the event and the amount of insider trading affect significantly foreign and institutional trading patterns. Furthermore, the relation between informed trading and insider trading is more enhanced when firms have a high level of discretionary accruals and a low book-to-market ratio. Prior studies have focused on the association between abnormal returns of insider trading and types of insider information disseminated, while informed trading patterns and insider trading with information uncertainty have not been specifically considered. This study enables practitioners to interpret corporate insider trading with information uncertainty on informed trading patterns.Целью данной работы является изучение влияния инсайдерской торговли на торговые модели иностранных и институциональных инвесторов, особенно в компаниях с высокими дискреционными начислениями и низким коэффициентом «книга к рынку» в качестве показателей информационной неопределенности. В данном исследовании используются такие методы, как модели торговли информированных трейдеров, которые, как считается, собирают более точную информацию до и после инсайдерской торговли, и проверяется, как инсайдерская торговля влияет на информированных трейдеров. Результаты данного исследования свидетельствуют о том, что инсайдерская торговля, вероятно, влияет на торговые модели информированных трейдеров. После контроля факторов, специфичных для конкретной фирмы, данное исследование обнаружило, что событие и объем инсайдерской торговли существенно влияют на модели торговли иностранных и институциональных трейдеров. Более того, связь между информированной и инсайдерской торговлей усиливается, когда фирмы имеют высокий уровень дискреционных начислений и низкий коэффициент «книга к рынку». Предыдущие исследования были сосредоточены на связи между аномальной доходностью инсайдерской торговли и видами распространенной информации от инсайдеров, в то время как модели информированной торговли и инсайдерской торговли в условиях информационной неопределенности специально не рассматривались. Данное исследование позволяет практикам интерпретировать корпоративную инсайдерскую торговлю с информационной неопределенностью на модели информированной торговли

Ricci Flat Black Holes and Hawking-Page Phase Transition in Gauss-Bonnet Gravity and Dilaton Gravity

It is well-known that there exists a Hawking-Page phase transition between a spherical AdS black hole and a thermal AdS space. The phase transition does not happen between a Ricci flat AdS black hole whose horizon is a Ricci flat space and a thermal AdS space in the Poincare coordinates. However, the Hawking-Page phase transition occurs between a Ricci flat AdS black hole and an AdS soliton if at least one of horizon coordinates for the Ricci flat black hole is compact. We show a similar phase transition betwen the Ricci flat black holes and deformed AdS solitons in the Gauss-Bonnet gravity and the dilaton gravity with a Liouville-type potential including the gauged supergravity coming from the spherical reduction of Dp-branes in type II supergravity. In contrast to Einstein gravity, we find that the high temperature phase can be dominated either by black holes or deformed AdS solitons depending on parameters.Comment: Latex, 17 pages without figure

Schwinger Pair Production at Finite Temperature in Scalar QED

In scalar QED we study the Schwinger pair production from an initial ensemble of charged bosons when an electric field is turned on for a finite period together with or without a constant magnetic field. The scalar QED Hamiltonian depends on time through the electric field, which causes the initial ensemble of bosons to evolve out of equilibrium. Using the Liouville-von Neumann method for the density operator and quantum states for each momentum mode, we calculate the Schwinger pair-production rate at finite temperature, which is the pair-production rate from the vacuum times a thermal factor of the Bose-Einstein distribution.Comment: RevTex 10 pages, no figure; replaced by the version accepted in Phys. Rev. D; references correcte

Nonperturbative QED Effective Action at Finite Temperature

We advance a novel method for the finite-temperature effective action for nonequilibrium quantum fields and find the QED effective action in time-dependent electric fields, where charged pairs evolve out of equilibrium. The imaginary part of the effective action consists of thermal loops of the Fermi-Dirac or Bose-Einstein distribution for the initial thermal ensemble weighted with factors for vacuum fluctuations. And the real part of the effective action is determined by the mean number of produced pairs, vacuum polarization, and thermal distribution. The mean number of produced pairs is equal to twice the imaginary part. We explicitly find the finite-temperature effective action in a constant electric field.Comment: RevTex4, 6pages, no figure; replaced by the version to be published in Phys. Rev.

Kajian Perancangan Karakter Maskot Universitas Pendidikan Mandalika

Mascot is a promotional media that is familiar in promotional media. Several companies to universities have mascots as icons that can represent higher education. UNDIKMA as a new joint-form campus has not used the media in the form of mascots for promotion. considering that NTB is a heterogeneous region with respect to ethnicity, religion, and race, so it requires a mascot as a brand ambassador for UNDIKMA. This is important because in the NTB region there is no tertiary institution that has a mascot. In the previous study, there was no study on mascot creation for universities. The purpose of this research is to design a mascot with a method approach that puts forward the target audience. While the method used is the Design Thinking Method developed by Tim Brown. Design thinking is a way to solve ambiguous and unfamiliar problems, rediscover problems in a human-centered way, brainstorm to generate multiple ideas, and take a hands-on approach. Very useful for prototyping and testing. Design thinking also includes continuous experimentation, such as sketching, prototyping, experimenting, and trying out different concepts and ideas. The target outcome of this research is to hopefully create a mascot design. In addition, it is also hoped that the output in the form of a mascot design guide line will also be successfully written. So that the application of the mascot can be correct and in accordance with the objectives expected by the designer

Electromagnetic fields in a 3D cavity and in a waveguide with oscillating walls

We consider classical and quantum electromagnetic fields in a three-dimensional (3D) cavity and in a waveguide with oscillating boundaries of the frequency $\Omega$. The photons created by the parametric resonance are distributed in the wave number space around $\Omega/2$ along the axis of the oscillation. When classical waves propagate along the waveguide in the one direction, we observe the amplification of the original waves and another wave generation in the opposite direction by the oscillation of side walls. This can be understood as the classical counterpart of the photon production. In the case of two opposite walls oscillating with the same frequency but with a phase difference, the interferences are shown to occur due to the phase difference in the photon numbers and in the intensity of the generated waves.Comment: 8 pages revTeX including 1 eps fi

Near-Infrared Coronagraphic Observations of the T Tauri Binary System UY Aur

We present a near-infrared image of UY Aur, a 0.9" separated binary system, using the Coronagraphic Imager with Adaptive Optics on the Subaru Telescope. Thanks to adaptive optics, the spatial resolution of our image was ~0.1" in the full width at half maximum of the point spread function, the highest achieved. By comparison with previous measurements, we estimated that the orbital period is ~1640 yrs and the total mass of the binary is ~1.73 solar mass. The observed H-band magnitude of the secondary varies by as much as 1.3 mag within a decade, while that of the primary is rather stable. This inconstancy may arise from photospheric variability caused by an uneven accretion rate or from the rotation of the secondary. We detected a half-ring shaped circumbinary disk around the binary with a bright southwest part but a barely detectable northeast portion. The brightness ratio is ~57. Its inner radius and inclination are about 520 AU and 42, respectively. The disk is not uniform but has remarkable features, including a clumpy structure along the disk, circumstellar material inside the inner cavity, and an extended armlike structure. The circumstellar material inside the cavity probably corresponds to a clump or material accreting from the disk onto the binary. The armlike structure is a part of the disk, created by the accretion from the outer region of the disk or encounters with other stellar systems.Comment: 16 pages, 6 figures; accepted for publication in A

Spatially Resolved Molecular Hydrogen Emission in the Inner 200AU Environments of Classical T Tauri Stars

We present 2.0-2.4micron integral field spectroscopy at adaptive optics spatial resolution (~0.''1) obtained with the Near-infrared Integral Field Spectrograph (NIFS) at Gemini North Observatory of six Classical T Tauri stars: T Tau, DG Tau, XZ Tau, HL Tau, RW Aur and HV Tau C. In all cases, the v=1-0 S(1) (2.12 micron) emission is detected at spatially extended distances from the central stars. The bulk of the H_2 emission is typically not spatially coincident with the location of continuum flux. Multiple transitions detected in the K-band spectra show that H_2 level populations are typical of gas in thermal equilibrium with excitation temperatures in the 1800K-2300 K range. Three of the stars have H_2 velocity profiles that are centered at the stellar radial velocity, and three show velocity shifts with respect to the system. Each of the stars studied here show observed excitation temperatures, spatial extents, and kinematics of the H_2 that are most consistent with shock excited emission from the inner regions of the known Herbig-Haro energy flows or from wide-angle winds encompassing the outflows rather than predominantly from UV or X-ray stimulated emission from the central stars. The data presented in this study highlights the sensitivity of adaptive optics-fed integral field spectroscopy for spatially resolving emission line structures in the environments of bright young stars.Comment: 50 pages, 13 Figures. Accepted for publication in the Astrophysical Journal. Full Resolution paper available at: http://www.astro.sunysb.edu/tracy/pubs/Beck07.pd

A Micro Molecular Bipolar Outflow From HL Tau

We present detailed geometry and kinematics of the inner outflow toward HL Tau observed using Near Infrared Integral Field Spectograph (NIFS) at the Gemini-North 8-m Observatory. We analyzed H2 2.122 um emission and [Fe II] 1.644 um line emission as well as the adjacent continuum observed at a <0".2 resolution. The H2 emission shows (1) a bubble-like geometry to the northeast of the star, as briefly reported in the previous paper, and (2) faint emission in the southwest counterflow, which has been revealed through careful analysis. The emission on both sides of the star show an arc 1".0 away from the star, exhibiting a bipolar symmetry. Different brightness and morphologies in the northeast and southwest flows are attributed to absorption and obscuration of the latter by a flattened envelope and a circumstellar disk. The H2 emission shows a remarkably different morphology from the collimated jet seen in [Fe II] emission. The positions of some features coincide with scattering continuum, indicating that these are associated with cavities in the dusty envelope. Such properties are similar to millimeter CO outflows, although the spatial scale of the H2 outflow in our image (~150 AU) is strikingly smaller than the mm outflows, which often extend over 1000-10000 AU scales. The position-velocity diagram of the H2 and [Fe II] emission do not show any evidence for kinematic interaction between these flows. All results described above support the scenario that the jet is surrounded by an unseen wide-angled wind, which interacts with the ambient gas and produce the bipolar cavity and shocked H2 emission.Comment: 13 pages, 4 figures, accepted for publication in ApJ