3,223 research outputs found

    Proto-type installation of a double-station system for the optical-video-detection and orbital characterisation of a meteor/fireball in South Korea

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    We give a detailed description of the installation and operation of a double-station meteor detection system which formed part of a research & education project between Korea Astronomy Space Science Institute and Daejeon Science Highschool. A total of six light-sensitive CCD cameras were installed with three cameras at SOAO and three cameras at BOAO observatory. A double-station observation of a meteor event enables the determination of the three-dimensional orbit in space. This project was initiated in response to the Jinju fireball event in March 2014. The cameras were installed in October/November 2014. The two stations are identical in hardware as well as software. Each station employes sensitive Watec-902H2 cameras in combination with relatively fast f/1.2 lenses. Various fields of views were used for measuring differences in detection rates of meteor events. We employed the SonotaCo UFO software suite for meteor detection and their subsequent analysis. The system setup as well as installation/operation experience is described and first results are presented. We also give a brief overview of historic as well as recent meteor (fall) detections in South Korea. For more information please consult http://meteor.kasi.re.kr .Comment: Technical/instrumentation description of a professional meteor detection system, 23 pages, 20 figures (color/monochrome), 5 tables, submitted to the Journal of Korean Astronomical Society (JKAS, http://jkas.kas.org/, http://jkas.kas.org/history.html

    Clinical Approach to the Standardization of Oriental Medical Diagnostic Pattern Identification in Stroke Patients

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    In Korea, many stroke patients receive oriental medical care, in which pattern-identification plays a major role. Pattern-identification is Oriental Medicine's unique diagnostic system. This study attempted to standardize oriental medical pattern-identification for stroke patients. This was a community-based multicenter study that enrolled stroke patients within 30 days after their ictus. We assessed the patients' general characteristics and symptoms related to pattern-identification. Each patient's pattern was determined when two doctors had the same opinion. To determine which variables affect the pattern-identification, binary logistic regression analysis was used with the backward method. A total of 806 stroke patients were enrolled. Among 480 patients who were identified as having a certain pattern, 100 patients exhibited the Fire Heat Pattern, 210 patients the Phlegm Dampness Pattern, nine patients the Blood Stasis Pattern, 110 patients the Qi Deficiency Pattern, and 51 patients the Yin Deficiency Pattern. After the regression analysis, the predictive logistic equations for the Fire Heat, Phlegm Dampness, Qi Deficiency, and Yin Deficiency patterns were determined. The Blood Stasis Pattern was omitted because the sample size was too small. Predictive logistic equations were suggested for four of the patterns. These criteria would be useful in determining each stroke patient's pattern in clinics. However, further studies with large samples are necessary to validate and confirm these criteria

    Emergent localized states at the interface of a twofold PT\mathcal{PT}-symmetric lattice

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    We consider the role of non-triviality resulting from a non-Hermitian Hamiltonian that conserves twofold PT-symmetry assembled by interconnections between a PT-symmetric lattice and its time reversal partner. Twofold PT-symmetry in the lattice produces additional surface exceptional points that play the role of new critical points, along with the bulk exceptional point. We show that there are two distinct regimes possessing symmetry-protected localized states, of which localization lengths are robust against external gain and loss. The states are demonstrated by numerical calculation of a quasi-1D ladder lattice and a 2D bilayered square lattice.Comment: 10 pages, 7 figure

    Determinants Of Enforcement Action By The Financial Supervisory Service Of Korea From The Perspective Of Audit Firms

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    In this study, we examine the determinants of enforcement action by the Financial Supervisory Service of Korea from the perspective of audit firms. Enforcement action is an indication of audit failure. Both client- and audit firm-specific factors are involved in its occurrence. Most published studies of enforcement after audit failure focus on client characteristics because details about audit firms from financial statements and information about organizational structure are not publicly available. However, examining the issues surrounding enforcement from the perspective of audit firms may also be valuable in elucidating the potential determinants of audit failure resulting in enforcement action. Utilizing publicly available data from audit firms in South Korea, we identify several audit firm characteristics as determinants of enforcement action. The results of our empirical analysis reveal that the likelihood of audit failure is positively associated with the ratio of accounts receivable to total assets, the ratio of audit fees to total revenue, the ratio of partners to the total number of CPAs, CEO ownership, and age of audit firms. In addition, the likelihood of audit failure is negatively associated with ownership concentration and profitability. These associations are more pronounced in non-affiliated audit firms than affiliated audit firms. Several useful implications for regulators are described for improving audit quality by means of enforcement action
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