http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Exchange Rate Risk and International Investment with Regime Switching Mixed Copula
Kyuwon Choi,Hyungsik Oh 한국재무학회 2011 한국재무학회 학술대회 Vol.2011 No.05
Benefits of international diversification heavily rely on the degree of dependence across securities. In this paper, we extend the results of Garcia and Tsafack (2007) regime switching mixed copula model to include Asian countries and explain the effect of exchange rate risk on the asymmetric dependence. Bootstrapped likelihood ratio tests show that asymmetric dependence of international market appears mostly insignificant when there is no exchange rate risk, while it appears significant with the presence of exchange rate risk. We suggest unwinding of foreign investment as one possible reason for these results.
Choi Ji Young,Yun Jihye,Heo Subin,Kim Dong Wook,Choi Sang Hyun,Yoon Jiyoung,Kim Kyuwon,Jung Kee Wook,Myung Seung-Jae 대한영상의학회 2023 Korean Journal of Radiology Vol.24 No.11
Objective: Cine magnetic resonance imaging (MRI) has emerged as a noninvasive method to quantitatively assess bowel motility. However, its accuracy in measuring various degrees of small bowel motility has not been extensively evaluated. We aimed to draw a quantitative small bowel motility score from cine MRI and evaluate its performance in a population with varying degrees of small bowel motility. Materials and Methods: A total of 174 participants (28.5 ± 7.6 years; 135 males) underwent a 22-second-long cine MRI sequence (2-dimensional balanced turbo-field echo; 0.5 seconds per image) approximately 5 minutes after being intravenously administered 10 mg of scopolamine-N-butyl bromide to deliberately create diverse degrees of small bowel motility. In a manually segmented area of the small bowel, motility was automatically quantified using a nonrigid registration and calculated as a quantitative motility score. The mean value (MV) of motility grades visually assessed by two radiologists was used as a reference standard. The quantitative motility score’s correlation (Spearman’s ρ) with the reference standard and performance (area under the receiver operating characteristics curve [AUROC], sensitivity, and specificity) for diagnosing adynamic small bowel (MV of 1) were evaluated. Results: For the MV of the quantitative motility scores at grades 1, 1.5, 2, 2.5, and 3, the mean ± standard deviation values were 0.019 ± 0.003, 0.027 ± 0.010, 0.033 ± 0.008, 0.032 ± 0.009, and 0.043 ± 0.013, respectively. There was a significant positive correlation between the quantitative motility score and the MV (ρ = 0.531, P < 0.001). The AUROC value for diagnosing a MV of 1 (i.e., adynamic small bowel) was 0.953 (95% confidence interval, 0.923–0.984). Moreover, the optimal cutoff for the quantitative motility score was 0.024, with a sensitivity of 100% (15/15) and specificity of 89.9% (143/159). Conclusion: The quantitative motility score calculated from a cine MRI enables diagnosis of an adynamic small bowel, and potentially discerns various degrees of bowel motility.
Entomopathogenic fungal infection of Allomyrina dichotoma in mass breeding conditions
( Kyuwon Kwak ),( Sunghee Nam ),( Hyowon Choi ),( Jiyoung Choi ),( Seokhyun Lee ),( Honggeun Kim ),( Myungsae Han ),( Kwanho Park ) 한국잠사학회 2015 International Journal of Industrial Entomology Vol.31 No.1
Increased use of rhinoceros beetles (Allomyrina dichotoma ) for food and medicine, and their elevated value as pets has led to an increase in the number of their breeding farms. Mass breeding of the insects in these farms leads to entomological diseases. In this study, we investigate cannibalism resulting from overcrowded breeding of A. dichotoma larvae, as well as secondary fungal infections in epidermal wounds in the surviving larvae. Some of the fungi detected in the present study showed entomopathogenicity, and the larvae showed different times of death. In particular, larvae infected with Clonostachys sp., an endophytic plant fungus, grew for a long time after infection, but died without pupating.
Choi, Dongcheol,Jeong, Hanall,Kim, Kyuwon The Royal Society of Chemistry 2014 The Analyst Vol.139 No.6
<P>Target protein-directed adsorption of graphene oxide (GO) as an electroactive indicator was employed for electrochemical detection of thrombin. The method was highly sensitive and the detection limit was as low as 9.7 pg ml<SUP>−1</SUP>.</P> <P>Graphic Abstract</P><P>Target protein-directed adsorption of graphene oxide (GO) as an electroactive indicator was employed for electrochemical detection of thrombin. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3an02197a'> </P>
Kim Kyuwon,Choi Kookhwan,Hwang Sung Wook,Im Jong Pil,Ye Byong Duk,Kim Joo Sung,Park Kyu Joo,Yang Suk-Kyun,Koh Seong-Joon,Park Sang Hyoung 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.4
Background/Aims: Owing to the low prevalence of small-bowel adenocarcinoma (SBA), data on the impact of Crohn’s disease (CD) on the survival of patients with SBA are lacking. Therefore, we investigated this issue in this study. Methods: In this bicenter cohort study, patients with histologically confirmed SBA were retrospectively enrolled and classified into two groups: sporadic SBA and CD-associated SBA. Patients with duodenal SBA were excluded. Overall survival, disease-free survival, and factors associated with survival were analyzed. Results: Of 128 patients with SBA, 115 had sporadic SBA and 13 had CD-associated SBA. Ileal involvement and poorly differentiated tumors were more common in the CD-associated SBA group than in the sporadic SBA group (ileal involvement, 53.8% vs 22.6%; poor differentiation, 46.2% vs 14.8%; both p<0.05). In survival analysis, overall survival showed no statistical difference between the sporadic SBA and CD-associated SBA groups (p=0.370). However, when stratified by stage, the adjusted overall survival of the CD-associated SBA group was lower in patients with an advanced disease stage (p=0.029). Disease-free survival showed the same tendency, albeit without clinical significance (p=0.097). CD (hazard ratio [HR], 2.308; p=0.047), older age (≥65 yr) at SBA diagnosis (HR, 2.766; p=0.001), and stage III/IV disease (HR, 3.151; p<0.001) were factors associated with mortality. Conclusions: The overall survival of patients with CD-associated SBA did not differ from that of patients with sporadic SBA. However, as CD is an independent risk factor for mortality, vigilant surveillance in high-risk patients may be crucial.
김규원(Kyuwon Kim),최재웅(Jaewoong Choi),이경수(Kyoungsu Yi) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11
This paper describes a comparative study of next-generation electric bus system in aspect of traveling performance and the fuel economy. In order to carry out mathematical analysis, three different driving systems are developed : series hybrid bus(SHEV), full electric bus(EV) and on-line electric bus(OLEV) which uses the inductive coupling system(ICS) to transfers energy from a coil buried beneath the road’s surface to the vehicle through a magnetic field. A power management algorithm is proposed to get an equivalent traveling performance and the fuel economy of the existing vehicle with three representative driving cycles. The comparative study of next-generation electric bus system is performed with the power management algorithm which is developed on the basis of an optimal control theory.