6,574 research outputs found

    Earnings Management Of Mergers And Acquisitions Of Target Candidates And Deal Withdrawn

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    In this paper, we investigate the tendencies of target candidate companies to manage earnings, which affects financial reporting quality, in order to increase transaction value, and the withdrawal of deals as a result of low financial reporting quality in M&A in a sample of 316 mergers and acquisitions in South Korea between 2002 and 2011. Using the accruals quality measure developed by Dechow and Dichev (2002) as a proxy for financial reporting quality, we find the following. First, the financial reporting quality of target candidate firms is lower than that of non-target candidate firms because target candidate firms engage in earnings management prior to M&A. Second, low-quality financial reporting of target firms is positively related to the likelihood of deal withdrawal as a result of poor financial reporting quality

    Biomarkers of Oxidative Stress and Endogenous Antioxidants for Patients with Chronic Subjective Dizziness

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    As a neurotologic disorder of persistent non-vertiginous dizziness, chronic subjective dizziness (CSD) arises unsteadily by psychological and physiological imbalance. The CSD is hypersensitivity reaction due to exposure to complex motions visual stimuli. However, the pathophysiological features and mechanism of the CSD still remains unclearly. The present study was purposed to establish possible endogenous contributors of the CSD using serum samples from patients with the CSD. A total 199 participants were gathered and divided into two groups; healthy (n = 152, male for 61, and female for 91) and CSD (n = 47, male for 5, female for 42), respectively. Oxidative stress parameters such as, hydrogen peroxide and reactive substances were significantly elevated (p < 0.01 or p < 0.001), whereas endogenous antioxidant components including total glutathione contents, and activities of catalase and superoxide dismutase were significantly deteriorated in the CSD group (p < 0.01 or p < 0.001) as comparing to the healthy group, respectively. Serum levels of tumor necrosis factor -α and interferon-γ were significantly increased in the CSD participants (p < 0.001). Additionally, emotional stress related hormones including cortisol, adrenaline, and serotonin were abnormally observed in the serum levels of the CSD group (p < 0.01 or p < 0.001). Our results confirmed that oxidative stress and antioxidants are a critical contributor of pathophysiology of the CSD, and that is first explored to establish features of redox system in the CSD subjects compared to a healthy population

    UNCERTAINTY PROPAGATION ANALYSIS FOR YONGGWANG NUCLEAR UNIT 4 BY MCCARD/MASTER CORE ANALYSIS SYSTEM

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    This paper concerns estimating uncertainties of the core neutronics design parameters of power reactors by direct sampling method (DSM) calculations based on the two-step McCARD/MASTER design system in which McCARD is used to generate the fuel assembly (FA) homogenized few group constants (FGCs) while MASTER is used to conduct the core neutronics design computation. It presents an extended application of the uncertainty propagation analysis method originally designed for uncertainty quantification of the FA FGCs as a way to produce the covariances between the FGCs of any pair of FAs comprising the core, or the covariance matrix of the FA FGCs required for random sampling of the FA FGCs input sets into direct sampling core calculations by MASTER. For illustrative purposes, the uncertainties of core design parameters such as the effective multiplication factor (keff), normalized FA power densities, power peaking factors, etc. for the beginning of life (BOL) core of Yonggwang nuclear unit 4 (YGN4) at the hot zero power and all rods out are estimated by the McCARD/MASTER-based DSM computations. The results are compared with those from the uncertainty propagation analysis method based on the McCARD-predicted sensitivity coefficients of nuclear design parameters and the cross section covariance data

    Optimal design of quadratic electromagnetic exciter

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    The vibration acceleration of collecting plates, which is the core indicator of rapping performance in an electrostatic precipitator’s vibration rapping process, is determined by magnetic force of a quadratic electromagnetic exciter. The larger exciter provides the larger magnetic force, but the installation space for the exciter is limited. Accordingly, this paper presents the optimal design of quadratic electromagnetic exciter to maximize the magnetic force with constraint that the size of exciter is constant. A design optimization problem was formulated in order to find the quadratic electromagnetic exciter shape parameters that maximized the magnetic force. The magnetic force of the quadratic electromagnetic exciter was evaluated using the commercial electromagnetic analysis software “MAXWELL”. For efficient design, we employed metamodel-based design optimization using design of experiments (DOE), metamodels, and an optimization algorithm equipped in PIAnO (Process Integration, Automation and Optimization), a commercial PIDO (Process Integration and Design Optimization) tool. Using the proposed design approach, the optimal magnetic force was increased by 1.68 % compared to the initial one. This result demonstrates the effectiveness of the established analysis and design procedure for the quadratic electromagnetic exciter

    Rapid and high-capacity MgO composites by salt-controllable precipitation for pre- combustion CO2 capture

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    Pre-combustion CO2 capture at intermediate temperatures can allow for more flexibility to control over CO2 emission in various industrial processes. For example, the pre-combustion capture can be applied for an Integrated Gasification Combined Cycle (IGCC) due to the use of relatively mild operating temperatures and accessible heat sources. Efficient materials for CO2 capture and H2 production in water gas shift reactor can contribute to improving the overall reliability and efficiency in IGCC process. As a first step, we presented triple salt-promoted MgO composites (NaNaLi salts) by a precipitation method to enhance sorption capacity, rate, and stability. In the conventional precipitation method, a filtration step makes control and reproductivity of the salt composition difficult owing to the unknown residual salts. In this study, we developed a synthesis procedure of precipitation method to control the composition of salts as well as improve physical properties. As-prepared MgO exhibited excellent sorption capacities of 73.0 wt.% at 325 °C in pure CO2 and high sorption rate within 10 min. Stability of composites were evaluated under various gas and time condition and were superior to those of the other MgO-based sorbents reported. With a wet gas mixture (29% CO2, 3% H2O, and balance N2) for sorption and CO2 regeneration, the working capacity stabilized after 20 cycles at 23 and 4.6 wt% for 60/15 min and 10/5 min cycles, respectively. The enhancement and reduction of working capacity along cycles were explained based on liquid phase sintering, i.e., rearrangement, solid-reprecipitation, and densification. However, too long sorption time in the capacity evaluation is not practical because a fixed bed or fluidized bed has a difficulty of temperature control and a large bed size to control high volumes of gases. Therefore, further development is required for an advanced sorbent with high sorption rate and capacity in practical utilization. Therefore, as a second step, a facile method for sorbent with rapid and high-capacity CO2 capture was developed by incorporating additional metal ioninto salt-promoted MgO sorbents using a coprecipitation. At the same fast cycle (10min/5min), the cyclic sorption capacity of 12 wt.% was observed from the developed MgO composite by using wet mixture sorption (29 vol.% CO2, vol.% H2O and N2 balance) and CO2 regeneration. Please click Additional Files below to see the full abstract
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