799 research outputs found
STOCK MARKET VOLATILITY AND THE FORECASTING ACCURACY OF IMPLIED VOLATILITY INDICES
This study develops a new model-free benchmark of implied volatility for the Japanese stock market similar in construction to the new VIX based on the S&P 500 index. It also examines the stochastic dynamics of the implied volatility index and its relationship with realized volatility in both markets. There is evidence that implied volatility is governed by a long-memory process. Despite its upward bias, implied volatility is more reflective of changes in realized volatility than alternative GARCH models, which account for volatility persistence and the asymmetric impact of news. The implied volatility index is also found to be inclusive of some but not all information on future volatility contained in historical returns. However, its higher out-of sample performance provides further support to the rationale behind drawing inference about future stock market volatility based on the incremental information contained in options prices.Licensing; Implied volatility index, Out-of-sample forecasting, GARCH modelling
The Term Structure of Implied Probability and Investment Strategies in the KOSPI200 Options Market
The effect of SOX on audit quality
© 2019, Emerald Publishing Limited. Purpose: This paper aims to investigate two issues. First, the authors test the effect of the SarbanesâOxley Act (SOX) on audit quality after 10 years. Second, the authors test whether it was necessary to close all of the Arthur Andersen offices due to the misbehavior of a few (e.g. the Houston and Atlanta offices). Design/methodology/approach: The authors have used conservatism (Basu) as a proxy for audit quality. Findings: The authors find that, over the long run (10 years) after SOX adoption, there is a significant positive change in conservatism as compared to during the previous similar period. In addition, the authors find that only 6 of the 20 city-level offices of Arthur Andersen were less conservative than were their other Big 6 competitors in the same city. Furthermore, the results also suggest that some city-level offices of Arthur Andersen were engaged in more conservative accounting practices than were their competitors and the Houston Andersen offices. Originality/value: This study documents, using empirical evidence, that the implementation of SOX is successful, and that one factor that helped lead to this success might be the harsh punishment on Arthur Andersen
Business Groups and Corporate Social Responsibility
© 2018, Springer Science+Business Media B.V., part of Springer Nature. There is a growing literature on corporate social responsibility (CSR), but few have focused on the implications of business groups for CSR. We examine the antecedents and outcomes of CSR behaviors of group firms in Korea. We find that group affiliation is associated with higher CSR overall and for its major societal and environmental components. However, the ownership disparity between cash flow and control by controlling inside shareholders is associated with lower CSR, consistent with opportunistic rent expropriation theory. We further find that CSR initiatives can impact group firms positively in the event of bad events, consistent with insurance theory. This motive for CSR as a means of enhancing reputation capital to buffer the bad events is pronounced for group firms because of group-wide dissemination of negative reputational externality
Tonicity response element binding protein associated with neuronal cell death in the experimental diabetic retinopathy
AIM: To study the contribution of tonicity response element binding protein (TonEBP) in retinal ganglion cell (RGC) death of diabetic retinopathy (DR).
METHODS: Diabetes was induced in C57BL/6 mice by five consecutive intraperitoneal injections of 55 mg/kg streptozotocin (STZ). Control mice received vehicle (phosphate -buffered saline). All mice were killed 2mo after injections, and the extent of cell death and the protein expression levels of TonEBP and aldose reductase (AR) were examined.
RESULTS: The TonEBP and AR protein levels and the death of RGC were significantly increased in the retinas of diabetic mice compared with controls 2mo after the induction of diabetes. Terminal deoxynucleotidyl transferase (TdT) -mediated dUTP nick end labeling (TUNEL) -positive signals co -localized with TonEBP immunoreactive RGC. These changes were increased in the diabetic retinas compared with controls.
CONCLUSION: The present data show that AR and TonEBP are upregulated in the DR and TonEBP may contribute to apoptosis of RGC in the DR.close2
Effect of Aquatic Exercise on Foot Pressure Balance and Posture Stability in Elderly Women
The purpose was investigate the foot pressure balance and body posture stability in elderly women. Sixteen elderly women participated in this study (mean age:72.63?~79.38?.46yrs, mean BMI: 25.03?.83~27.99?.78). They were divided into two groups (aqua exercise group, n=8, control group, n=8). Participants were tested before and after the study to measure foot pressure balance, body posture stability and advanced balance ability(limits of stability) were measured Biorescure(RM Ingenierie Co, France) which has % quarterly sector(RF, LF, RB, LB). Aqua exercise training program was performed for 50minutes per session, 3times per week for 12weeks. Data was analyzed with ANOVA for repeated measures, t-test using SPSS ver 19.0 program. Aquatic exercise considered a senior citizen fall prevention and improved quality of life
Sejong Open Cluster Survey (SOS). 0. Target Selection and Data Analysis
Star clusters are superb astrophysical laboratories containing cospatial and
coeval samples of stars with similar chemical composition. We have initiated
the Sejong Open cluster Survey (SOS) - a project dedicated to providing
homogeneous photometry of a large number of open clusters in the SAAO
Johnson-Cousins' system. To achieve our main goal, we have paid much
attention to the observation of standard stars in order to reproduce the SAAO
standard system.
Many of our targets are relatively small, sparse clusters that escaped
previous observations. As clusters are considered building blocks of the
Galactic disk, their physical properties such as the initial mass function, the
pattern of mass segregation, etc. give valuable information on the formation
and evolution of the Galactic disk. The spatial distribution of young open
clusters will be used to revise the local spiral arm structure of the Galaxy.
In addition, the homogeneous data can also be used to test stellar evolutionary
theory, especially concerning rare massive stars. In this paper we present the
target selection criteria, the observational strategy for accurate photometry,
and the adopted calibrations for data analysis such as color-color relations,
zero-age main sequence relations, Sp - Mv relations, Sp - Teff relations, Sp -
color relations, and Teff - BC relations. Finally we provide some data analysis
such as the determination of the reddening law, the membership selection
criteria, and distance determination.Comment: 21 pages, 16 figures, accepted for publication in J. of Korean
Astronomical Society (JKAS
Magnetic phase diagram of CePt3B1-xSix
We present a study of the main bulk properties (susceptibility,
magnetization, resistivity and specific heat) of CePt_3B_(1-x)Si-x, an alloying
system that crystallizes in a noncentrosymmetric lattice, and derive the
magnetic phase diagram. The materials at the end point of the alloying series
have previously been studied, with CePt_3B established as a material with two
different magnetic phases at low temperatures (antiferromagnetic below T_N =
7.8 K, weakly ferromagnetic below T_C ~ 5 K), while CePt3Si is a heavy fermion
superconductor (T_c = 0.75 K) coexisting with antiferromagnetism (T_N = 2.2 K).
From our experiments we conclude that the magnetic phase diagram is divided
into two regions. In the region of low Si content (up to x ~ 0.7) the material
properties resemble those of CePt3B. Upon increasing the Si concentration
further the magnetic ground state continuously transforms into that of CePt3Si.
In essence, we argue that CePt_3B can be understood as a low pressure variant
of CePt3Si.Comment: 7pages, 9figure
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