4,905 research outputs found

    A Measure Based on Beamforming Power for Evaluation of Sound Field Reproduction Performance

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    This paper proposes a measure to evaluate sound field reproduction systems with an array of loudspeakers. The spatially-averaged squared error of the sound pressure between the desired and the reproduced field, namely the spatial error, has been widely used, which has considerable problems in two conditions. First, in non-anechoic conditions, room reflections substantially deteriorate the spatial error, although these room reflections affect human localization to a lesser degree. Second, for 2.5-dimensional reproduction of spherical waves, the spatial error increases consistently due to the difference in the amplitude decay rate, whereas the degradation of human localization performance is limited. The measure proposed in this study is based on the beamforming powers of the desired and the reproduced fields. Simulation and experimental results show that the proposed measure is less sensitive to room reflections and the amplitude decay than the spatial error, which is likely to agree better with the human perception of source localization

    Effects of depolarizing quantum channels on BB84 and SARG04 quantum cryptography protocols

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    We report experimental studies on the effect of the depolarizing quantum channel on weak-pulse BB84 and SARG04 quantum cryptography. The experimental results show that, in real world conditions in which channel depolarization cannot be ignored, BB84 should perform better than SARG04.Comment: 4 pages, 4 figure

    The Study On The Effect And Determinants Of Small - And Medium-Sized Entities Conducting Tax Avoidance

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    SME often lack the capacity to keep transparency in management due to a small number of information users. Thus, the adoption of K-IFRS can be burdensome to numerous SME, which led to the enactment of Accounting Standards for Small- and Medium-sized Entities (AS-SME). AS-SME allows the accountants to easily implement accounting rules when writing financial statements and the users to comprehend useful information. SME hold less tax burden since they receive a tax deduction and exemption from the Tax Act. Thus, we conjecture that the financial determinants of tax avoidance between SME and non-SME will differ. We divide the total sample according to the corporate tax avoidance and empirically examine whether the difference actually exists. Our sample consists 18,954 audited firms including those external audited from 2011 to 2013. This study implements BTD, the difference between accounting profit and taxable income and estimated corporate tax avoidance (TS), which is the part that cannot be explained by total accruals in BTD to proxy for tax avoidance. (Desai and Dharmapala 2006). We summarize our findings as below: there is a significant distinction between SME and non-SME regarding the related financial determinants. The result shows that firm size (SIZE), profitability (ROA), leverage (LEV), operating cash flow(CFO), capital intensity (PPE), R&D intensity (RNDS), and growth rate (GS) all influence the corporate tax avoidance of SME. Our result also suggests that there is variation in the determinants among the SME with high corporate tax avoidance. The attempt to investigate the financial determinants of the tax avoidance in SME can be a barometer of the effectiveness of AS-SME, which is enacted to lessen the tax burden of the SME. We intend to provide policy implication regarding SME subsidy by examining the motive for corporate tax avoidance in SME

    Reported Profits And Effective Tax Rate Following Accounting Standards Changes Analysis Of Consolidated Financial Statements And Separate Financial Statements

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    This study empirically examines how the adoption of IFRS affected the reported profits and effective tax rates of firms by analyzing consolidated financial statements and separate financial statements. Firms that adopted IFRS in 2011 were required to disclose consolidated financial statements and separate financial statements in both K-IFRS and K-GAAP for this period. We conjecture that there will be a difference in the reported profits and effective tax rates between the financial statements that adopt the two different accounting standards. This study will provide policy implications with regards to the recent IFRS adoption and the use of accounting standards. The findings of this study are as follows. First, we find that the effective tax rate and corporate tax expenses decreased after the adoption of K-IFRS from K-GAAP. Earnings Before Tax (EBT) and net income also decreased when reported in K-IFRS. When we divide the total sample into the listed firms and KOSDAQ firms, we found a significant difference between the accounting standards in the total sample and listed firms, but did not see such a difference in KOSDAQ firms. In addition, results from the analysis of separate financial statements were analogous to those from consolidated financial statements. Additional analyses examined the effect of the early adoption of IFRS, but a significant influence due to early adoption was not found in consolidated financial statements from both parametric and non-parametric tests. However, the effective tax rate did decrease in the separate financial statements of firms that adopted K-IFRS earlier. The implementation of K-IFRS (changes in accounting standards) has made the managerial performance of firms accounted for in the Equity Method to be reflected in EBT and net income. This entailed an increase (or decrease) in the Equity Method profit, which in turn increased reported profits and decreased effective tax rates. In other words, the total increase of reported profits in consolidated financial statements can be attributed to subsidiary companies. However, the adoption of IFRS also reduced the tax burden, which is considered to be the motivation for firms to adopt IFRS in advance. This article attempts to provide policy implications with regards to the adoption of new accounting standards and its influence on the corporate tax expenses and effective tax rates in listed firms and KOSDAQ firms. &nbsp

    Neuroprotective and anti-oxidant effects of caffeic acid isolated from Erigeron annuus leaf

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    <p>Abstract</p> <p>Background</p> <p>Since oxidative stress has been implicated in a neurodegenerative disease such as Alzheimer's disease (AD), natural antioxidants are promising candidates of chemopreventive agents. This study examines antioxidant and neuronal cell protective effects of various fractions of the methanolic extract of <it>Erigeron annuus </it>leaf and identifies active compounds of the extract.</p> <p>Methods</p> <p>Antioxidant activities of the fractions from <it>Erigeron annuus </it>leaf were examined with [2,2-azino-bis(3-ethylbenz thiazoline-6-sulfonic acid diammonium salt)] (ABTS) and ferric reducing antioxidant power (FRAP) assays. Neuroprotective effect of caffeic acid under oxidative stress induced by H<sub>2</sub>O<sub>2 </sub>was investigated with [3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) and lactate dehydrogenase (LDH) assays.</p> <p>Results</p> <p>This study demonstrated that butanol fraction had the highest antioxidant activity among all solvent fractions from methanolic extract <it>E. annuus </it>leaf. Butanol fraction had the highest total phenolic contents (396.49 mg of GAE/g). Caffeic acid, an isolated active compound from butanol fraction, showed dose-dependent <it>in vitro </it>antioxidant activity. Moreover, neuronal cell protection against oxidative stress induced cytotoxicity was also demonstrated.</p> <p>Conclusion</p> <p><it>Erigeron annuus </it>leaf extracts containing caffeic acid as an active compound have antioxidative and neuroprotective effects on neuronal cells.</p

    A MODEL ON AN ENTRAINED BED-BUBBLING BED PROCESS FOR CO2 CAPTURE FROM FLUE GAS

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    A simplified model has been developed to investigate effects of important operating parameters on performance of an entrained-bed absorber and bubbling-bed regenerator system collecting CO2 from flue gas. The particle population balance was considered together with chemical reaction to determine the extent of conversion in both absorber and regenerator. Effects of several absorber parameters was tested in a laboratory scale process. The CO2 capture efficiency decreased as temperature or gas velocity increased. However, it increased with static bed height or moisture concentration. The CO2 capture efficiency was exponentially proportional to each parameter. Based on the absolute value of exponent of the parameter, the effect of gas velocity, static bed height, and moisture content was a half, one third, and one fourth as strong as that of temperature, respectively

    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

    Construction of phylogenetic trees by kernel-based comparative analysis of metabolic networks

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    BACKGROUND: To infer the tree of life requires knowledge of the common characteristics of each species descended from a common ancestor as the measuring criteria and a method to calculate the distance between the resulting values of each measure. Conventional phylogenetic analysis based on genomic sequences provides information about the genetic relationships between different organisms. In contrast, comparative analysis of metabolic pathways in different organisms can yield insights into their functional relationships under different physiological conditions. However, evaluating the similarities or differences between metabolic networks is a computationally challenging problem, and systematic methods of doing this are desirable. Here we introduce a graph-kernel method for computing the similarity between metabolic networks in polynomial time, and use it to profile metabolic pathways and to construct phylogenetic trees. RESULTS: To compare the structures of metabolic networks in organisms, we adopted the exponential graph kernel, which is a kernel-based approach with a labeled graph that includes a label matrix and an adjacency matrix. To construct the phylogenetic trees, we used an unweighted pair-group method with arithmetic mean, i.e., a hierarchical clustering algorithm. We applied the kernel-based network profiling method in a comparative analysis of nine carbohydrate metabolic networks from 81 biological species encompassing Archaea, Eukaryota, and Eubacteria. The resulting phylogenetic hierarchies generally support the tripartite scheme of three domains rather than the two domains of prokaryotes and eukaryotes. CONCLUSION: By combining the kernel machines with metabolic information, the method infers the context of biosphere development that covers physiological events required for adaptation by genetic reconstruction. The results show that one may obtain a global view of the tree of life by comparing the metabolic pathway structures using meta-level information rather than sequence information. This method may yield further information about biological evolution, such as the history of horizontal transfer of each gene, by studying the detailed structure of the phylogenetic tree constructed by the kernel-based method
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