4,134 research outputs found
Corporate Social Responsibility and Corporate Financial Performance: Evidence from Korea
This paper studies the empirical relation between corporate social responsibility (CSR) and corporate financial performance in Korea using a sample of 1122 firm-years during 2002-2008. We measure corporate social responsibility by both an equal-weighted CSR index and a stakeholder-weighted CSR index suggested by Akpinar et al. (2008). Corporate financial performance is measured by ROE, ROA and Tobin’s Q. We find a positive and significant relation between corporate financial performance and the stakeholder-weighted CSR index, but not the equal-weighted CSR index. This finding is robust to alternative model specifications and several additional tests, providing evidence in support of instrumental stakeholder theory.corporate social responsibility; corporate financial performance; KEJI index; instrumental stakeholder theory
Does earnings management influence credit rating changes in subsequent periods?: An analysis of KRX firms
Mandatory audit firm rotation and Big4 effect on audit quality: evidence from South Korea
In South Korea, due to concurrent financial scandals, Korean legislators implemented
two major audit policies in the 2000s; the mandatory audit “partner” rotation policy
in 2000 and the mandatory audit “firm” rotation policy in 2006. The mandatory audit
“firm” rotation policy was introduced as a mean to improve audit quality based on
the auditor entrenchment hypothesis. In this paper, we compare the audit quality of
firms subjected to mandatory audit “firm” rotation with two benchmark groups, a
sample that adopted the policy voluntarily; the second group consists of the mandatory
“firm” rotation sample in years prior, a period firms were subject to mandatory audit
“partner” rotation. Using accrual-based measures as proxies for audit quality, we find
evidence that audit quality of the mandatory rotation firm sample is lower compared to
firms that voluntarily adopted the policy. Furthermore, we find evidence that audit quality
of the mandatory rotation firm sample is lower compared to the mandatory audit partner
firm sample. Additionally, we also find evidence that the mandatory audit firms rotation
sample whose auditors were rotated from Non-Big4 to Big4 are generally associated with
lower levels of abnormal accruals consistent with the argument that the audit quality of
Big4 accounting firms is superior to Non-Big4 firms. Finally, longer audit tenure and
switches to Big4 audit firms generally have a positive effect upon audit quality. These
findings suggest that extended audit tenure improves audit quality due to accounting firm’s accumulated client specific knowledge. Thus, our evidence suggests that the mandatory audit firm rotation policy did not have the desired effect in a Korean context
Breakdown of the interlayer coherence in twisted bilayer graphene
Coherent motion of the electrons in the Bloch states is one of the
fundamental concepts of the charge conduction in solid state physics. In
layered materials, however, such a condition often breaks down for the
interlayer conduction, when the interlayer coupling is significantly reduced by
e.g. large interlayer separation. We report that complete suppression of
coherent conduction is realized even in an atomic length scale of layer
separation in twisted bilayer graphene. The interlayer resistivity of twisted
bilayer graphene is much higher than the c-axis resistivity of Bernal-stacked
graphite, and exhibits strong dependence on temperature as well as on external
electric fields. These results suggest that the graphene layers are
significantly decoupled by rotation and incoherent conduction is a main
transport channel between the layers of twisted bilayer graphene.Comment: 5 pages, 3 figure
De novo transcriptome analysis of high growth rate Pyropia yezoensis (Bangiales, Rhodophyta) mutant with high utilization of nitrogen
Pyropia yezoensis (Ueda) M.S.Hwang et H.G.Choi (Bangiales, Rhodophyta) has potentially high economic value. P. yezoensis has been used as food in East Asian countries for a long time, and, in addition to that its consumption is increasing worldwide owing to the growing interest in healthy seaweed food. A mutant (Py2K) with a high growth rate was developed using gamma rays to increase the production of P. yezoensis. De novo transcriptome analysis was performed to determine the mechanism underlying the high growth rate of this mutant. The transcriptomes from wild-type (PyWT) and mutant (Py2K) strains were assembled, and 167,165 genes were analyzed. A total of 15,979 genes were differentially expressed. Transcriptome analysis of nitrogen pathway revealed the increase in nitrogen availability through the upregulation of nitrate transporter gene (nrt) expression. Activation of nitrogen assimilation and re-assimilation and upregulation in alternative oxidase (aox) gene contributed to the increase in cellular nitrogen availability, thereby affecting the synthesis of phycobiliprotein. As a consequence, the efficiency of photosynthesis and the subsequent growth rate increased, which contributed to the color differences in thalli between PyWT and Py2K
An improved baculovirus insecticide producing occlusion bodies that contain Bacillus thuringiensis insect toxin
Baculovirus occlusion bodies, large proteinaceous structures which contain virions, have recently been engineered to incorporate foreign proteins. The major constituent protein of occlusion bodies from the baculovirus Autographa californica nucleopolyhedrovirus is polyhedrin, and assembly of recombinant occlusion bodies which incorporate a foreign protein depends on an interaction between native polyhedrin and a polyhedrin–foreign protein fusion. This technology has now been applied to the generation of a recombinant baculovirus (ColorBtrus) that produces occlusion bodies incorporating the Bacillus thuringiensis (Bt) insecticidal Cry1Ac toxin protein. ColorBtrus coexpresses native polyhedrin and a fusion protein in which polyhedrin is fused to the Bt toxin, which is in turn fused to green fluorescent protein (GFP). Analysis of ColorBtrus occlusion bodies confirmed that they include both Bt toxin and GFP, yet still incorporate virions. Bioassay of ColorBtrus demonstrated that its speed of action and pathogenicity are strikingly enhanced compared to wild-type virus. ColorBtrus represents a novel, powerful biological insecticide that combines positive attributes of both Bt toxin and baculovirus based systems
Health-related quality of life with KDQOL-36 and its association with self-efficacy and treatment satisfaction in Korean dialysis patients
BACKGROUND AND OBJECTIVES: This study was conducted to measure the level of health-related quality of life (HRQOL) and to reveal the association of self-efficacy and treatment satisfaction with it in Korean dialysis patients. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: The study subjects were 237 patients receiving either hemodialysis (HD) or peritoneal dialysis (PD) from two university hospitals, from February to June in 2010. We investigated HRQOL using the Korean version of Kidney Disease Quality of Life Short Form 36 (KDQOL-36), and self-efficacy and treatment satisfaction by self-administrative questionnaire and their dialysis-related variables by reviewing clinical records. The associations of self-efficacy and treatment satisfaction with HRQOL were assessed using multiple linear regression analysis. RESULTS: The mean HRQOL results were as follows: Physical component score (PCS) was 39.1 ± 8.5, Mental component score (MCS) 44.6 ± 6.8, symptom/problem list was 67.6 ± 17.1, effects of disease score was 58.5 ± 19.6, and burden of disease score was 41.1 ± 28.4. Between PD and HD patients, we could find significant difference only in the symptom/problem list. After removing confounder’s effects by multivariate analysis, respectively, treatment goal self-efficacy and treatment management self-efficacy were significantly related with all 5 domains, except PCS. Treatment satisfaction was significantly related with PCS, MCS, and effects of kidney disease. CONCLUSIONS: Patients’ self-efficacy and treatment satisfaction could influence their HRQOL. Regular and systematic monitoring using KDQOL-36 and interventions to increase self-efficacy and treatment satisfaction should be considered in dialysis care in Korea
Band gap opening by two-dimensional manifestation of Peierls instability in graphene
Using first-principles calculations of graphene having high-symmetry
distortion or defects, we investigate band gap opening by chiral symmetry
breaking, or intervalley mixing, in graphene and show an intuitive picture of
understanding the gap opening in terms of local bonding and antibonding
hybridizations. We identify that the gap opening by chiral symmetry breaking in
honeycomb lattices is an ideal two-dimensional (2D) extension of the Peierls
metal-insulator transition in 1D linear lattices. We show that the spontaneous
Kekule distortion, a 2D version of the Peierls distortion, takes place in
biaxially strained graphene, leading to structural failure. We also show that
the gap opening in graphene antidots and armchair nanoribbons, which has been
attributed usually to quantum confinement effects, can be understood with the
chiral symmetry breaking
Refining Historical earthquake Data Through Modeling and Scale Model Tests
This study was performed for the reevaluation of historical earthquake records which occurred in Korea through tests and numerical analyses. For the scale model tests, static and cyclic lateral load tests on wooden frames that constitute a Korean ancient commoner’s house were conducted. Full-scale models of two types of frames were used for testing. Two 1:4 scale models were tested for rock and soil foundation conditions. Scaled real earthquake time histories were inputted for the tests. The peak ground acceleration (PGA) at the collapse of the house at the soil site was 0.25g, whereas PGA for moderate damage at the rock site was 0.6g. The intensity of major historical earthquake records related with house collapses was reevaluated based on the results of these scale mode1 tests. The magnitudes of historical earthquake records related with house collapses were estimated considering the magnitude, epicentral distance, soil condition and aging of the house. Eighteen artificial time histories for magnitudes 6-8, epicentral distances 5 km - 350 km and hard and soft soil condition were generated. The aging effects of the house was modeled as the lateral loading capacity of wooden frames represented by hysteretic stiffness decreased linearly with time
Earnings management surrounding CEO turnover: evidence from Korea
This article examines the empirical relation between CEO turnover and earnings management in Korea using a sample of 317 CEO turnovers and 634 non-turnover control firms during the period of 2001-2008. We classify CEO turnovers into four types depending on whether the departure of outgoing CEO is peaceful or forced and the incoming CEO is promoted from within or recruited from outside the firm. We measure earnings management by both discretionary accruals and real activities management. We also control for the potential endogeneity of CEO turnover using Heckman’s two-stage approach. After controlling for corporate financial performance and governance structure, we find upward earnings management by the departing CEO only when the departure is forced and the new CEO is an insider. In this case, the new CEO also engages in downward earnings management using both discretionary accruals and real activities management. We also find some evidence that the new CEO recruited from outside the firm manages discretionary accruals upward following the peaceful departure of predecessor. In all other types of CEO turnover, we do not find evidence of significant earnings management by either CEO
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