VKOSPI 지수의 비대칭성 연구

조정근 ( Joung Keun Cho ),최우석 ( Woo Suk Choi ),최강석 ( Kang Suk Choe ) 아시아.유럽미래학회 2015 유라시아연구 Vol.12 No.4

대한민국의 대표적인 대형주 지수인 코스피 200지수와 추정모델에 기반하지 않은 변동성지수인 VKOSPI 지수 분석을 통해 대형주 주가지수와 변동성지수간 통계적으로 유의한 부(負)의 관계가 확인되었다. 본 연구는 정보제공지수로서의 VKOSPI 변동성지수의 비대칭적 정보성격의 규명에 주안점이 주어졌다. 본 연구진은 (1) 2003년부터 2007년말까지를 위험회피도 하락 및 양(陽)의 주가지수수익률 국면, (2)2008년부터 2011년말까지를 위험회피도 상승 및 지수수익률 변동성 확대국면 및 (3) 2012년부터 본 연구데이터의 마지막 기간인 2015년 5월29일 (영업일 기준)까지 미미한 주가지수수익률을 기록한 위험회피도 조정국면으로 대 분류 하여 국면별 비대칭성분석을 진행하였다. 연구결과 코스피200 지수수익률과 VKOSPI 변동성지수간에는 크게 두 가지 비대칭성이 존재하였는데, 첫째는 음(陰)의 주가지수수익률에 따른 VKOSPI지수의 상승폭이 양(陽)의 주가지수수익률에 따른 VKOSPI지수의 하락폭보다 훨씬 컸다는 점과, 둘째로 위험회피도 조정국면인 P3기간 동안 음(陰)의 주가지수 수익률로 인한 VKOSPI지수의 민감도가 여타 위험회피도 국면들에 비해 상대적으로 컸다는 점이다. 이는 위험회피도 조정국면에서 시장참여자들은 음(陰)의 주가지수수익률에 대해 위험회피도 상승국면에 비해 예상변동성의 변화량을 옵션가격에 보다 적극적으로 반영하는 방식으로 상대적인 민감도 상승을 시현한 것으로 판단된다. For the KOSPI200 Index (“Index”), a negative and statistically significant relationship exists between the returns of the Index and VKOSPI, the official model-free implied volatility index. The primary research purpose is to test VKOSPI as an informative and meaningful trading indicator. The authors reorganized the data sample into 3 sub-periods: (1) Falling Risk-Aversion Regime: From January 2, 2003 to December 28, 2007 (P1) of pre-global financial crisis period of a declining VKOSPI, a positive market return and relatively small VKOSPI fluctuations. (2) Rising Risk-Aversion Regime: From January 2, 2008 to December 29, 2011 (P2) as the period of elevated VKOSPI and market stress. Steady risk-Aversion Regime: (3) From January 2, 2012 to May 29, 2015 (P3) a very low, consistent VKOSPI with mediocre market returns, especially in Korean equities. Two types of asymmetric relationships exist; (1) negative stock index returns yield larger impact inVKOSPI than positive returns do, (2) VKOSPI has a larger response to negative Index returns during a steady risk-aversion and stable market return period. Specifically, this happens when market participants tend to become more sensitive to substantial bearish market movements. Market participants subsequently become more sensitive in pricing them into the expected volatilities than in periods of rising risk aversion.

경주지역 가와사끼병의 임상적 고찰

정재열,Seo, Yu Kyong,김애숙,이선주,조성민,이동석,김두권,최성민 東國大學校醫學硏究所 2007 東國醫學 Vol.14 No.1

현재 한국에서 1990년 이후로 약 3년마다 전국적인 역학적 연구 결과를 발표하고 있으나, 경주 지역에서의 역학적 연구 결과는 현재까지 없는 실정이다. 이에 저자들은 최근 7년 동안 경주 지역 가와사끼병 환자에 대한 역학적인 고찰과 함께 임상적 특징을 알아보고자 본 연구를 시행하였다. 2000년 1월 1일부터 2006년 12월 31일까지 7년 동안 동국대학교 경주병원 소아과에 가와사끼병으로 입원한 환자 총 100명을 대상으로 하였다. 임상 증상, 검사 소견 및 심초음파 검사에 의한 관상동맥 합병증 등을 의무기록지를 통하여 후향적으로 분석하였다. 가와사끼병의 남녀 비는 1.7:1이었고,평균 나이는 약 32개월이었다. 각 계절별 차이는 크게 없었으며, 정형 가와사끼병은 83%, 비정형 가와사끼병은 17%였다. 양측성 결막 충혈 93%, 입술의 홍조 및 균열, 혀 , 구강 발적 등이 93%, 부정형 발진 91%,손발의 경성 부종과 홍조 80%,급성기의 비화농성 경부 림프절 비대가 52%의 빈도로 각각 발현하였다. 관상 동맥류는 7%에서 발생하였다. 관상 동맥류 발생을 예측할 수 있는 위험 인자를 보면, ALT(p=0.04), 알부민(p=0.008), CRP(p=0.027), IVIG 초회 치료에 반응이 없는 경우(p=0.001), 농뇨(p=0.046)가 통계적으로 유의하였다. 고용량의 IVIG의 초회 치료에 반응하지 않은 경우는 14%였다. IVIG 초회 치료에 반응하지 않는 군을 예측할 수 있는 위험 인자를 보면 AST (p=0.019), ALT(p=0.003), ESR(p=0.017), 농뇨(p=0.047)가 통계적으로 유의하였다. 경주 지역 가와사끼병의 임상 양상은 다른 연구 결과들과 크게 다르지 않았으며,가와사끼병에서 관상통맥류의 위험 인자도 다른 연구에서와 마찬가지로 유사한 것으로 생각된다. From 1990, nationwide epidemologic studies of Kawasaki disease have been conducted every 3 years in Korea, yet no study has been reported from Gyeongju. We investigated epidemiology and clinical characteristics of Kawasaki disease in Gyeongju for 7 years. We retrospectively analyzed the medical records of 100 Kawasaki disease patients, admitted to the Dongguk University Hospital Pediatrics from January 1st, 2000 to December 31st 2006, based on clinical symptoms, laboratory findings and coronary artery cumplications by echocardiography. Male tu female ratio was 1.7:1 and mean age was 32 months. There was no seasonal variation. Incidences of typical and atypical Kawasaki disease were 83% and 17%, respectively. Incidence of occurring symptoms were as follows: 93% of conjunctival injection; 93% of lip redness fissuring, tongue and oral erythema; 91% of amorphous skin rash; 80% of hand, foot erythema and edema; 52% of non-purulent cervical lymph node enlargement. For others, 46% of pyuha. 7% of coronary artery aneurysm was noted. Significant predictable risk factors for coronary artery aneurysm were ALT(p=0.04), albumin (0=0.008), CRP(D=0.027), nonresponsiveness to initial IVIG(intravenous immunoglobulin) treatment(p=0.001) and pyuria(p=0.046). 14% of patients were unresponsive to initial high dose IVIG treatment. Significant predictable risk factors for initial IVIG treatment failure were AST(p=0.019), ALT(p=0.003), ESR(p=0.017) and pyuria(p=0.047). The results of our study on epidemiologic and clinical characteristics of Kawasaki disease in Gyeongju were similar to other studies. Also, predictable risk factors of coronary artery aneurysm and initial high dose IVIG treatment failure were as similar as in other studies.

154kV용 활선 안전 경보기 개발에 관한 연구

정민규,조현광,우종수,안창회,서영석,김응태,박창기,오세득 영남대학교 공업기술연구소 2000 工業技術硏究所論文集 Vol.28 No.1

In this report we developed a high voltage alarm for the safety of workers who check and repair the 154kV power line. This high voltage alarm we developed is attached on workers' helmet and alarms automatically in order to let workers know when workers work over the safety distance near 154kV power line. Until now the exact safety distance hasn't been regulated and high voltage alarm we've been using was for the range of 6∼22.9kV power line. We fabricated this high voltage alarm on the basis of electric density and actual measurement of power line. The experimental result was that high voltage alarm at 66kV power line alarmed near 90cm, at 154kV power line alarmed near 160cm from the line. Accordingly, we developed the new high voltage alarm which is operated in the range of 66∼154kV power line.

Characterization of Lactic Acid Bacteria Isolated from Sauce-type Kimchi

Suk Hee Jung,Joung Whan Park,Il Jae Cho,Nam Keun Lee,In-Cheol Yeo,Byung Yong Kim,Hye Kyung Kim,Young Tae Hahm 한국식품영양과학회 2012 Preventive Nutrition and Food Science Vol.17 No.3

This study was carried out to investigate the isolation and characterization of lactic acid bacteria (LAB) from naturally fermented sauce-type kimchi. Sauce-type kimchi was prepared with fresh, chopped ingredients (Korean cabbage, radish, garlic, ginger, green onion, and red pepper). The two isolated bacteria from sauce-type kimchi were identified as Pediococcus pentosaceus and Lactobacillus brevis by 16S rDNA sequencing and tentatively named Pediococcus sp. IJ-K1 and Lactobacillus sp. IJ-K2, respectively. Pediococcus sp. IJ-K1 was isolated from the early and middle fermentation stages of sauce-type kimchi whereas Lactobacillus sp. IJ-K2 was isolated from the late fermentation stage. The resistance of Pediococcus sp. IJ-K1 and Lactobacillus sp. IJ-K2 to artificial gastric and bile acids led to bacterial survival rates that were 100% and 84.21%, respectively.

Market Timing with the VKOSPI Refined Composite Multiscale Entropy Indicator

Joung Keun Cho,Woo Suk Choi 한국산업경제학회 2016 산업경제연구 Vol.29 No.5

대한민국 주식시장의 대표적인 대형주 지수인 코스피 200지수와 추정모델에 기반하지 않은 변동성지수인 VKOSPI 변동성지수 분석을 통해 대형주 주가지수와 변동성지수간 통계적으로 유의한 부(負)의 관계를 확인하였다. 본 연구는 VKOSPI 변동성지수의 비대칭적 정보성격의 존재하에서 의미있는 정보지수로서의 VKOSPI Refined Composite Multiscale Entropy 변동성지표를 활용한 알고리즘 트레이딩 전략을 개발하는데 주안점을 두었다. VKOSPI Refined Composite Multiscale Entropy 지표의 변동에 따른 코스피200 주가지수선물의 Long 및 Short 매매전략이 본 연구에서 개발된 알고리즘 트레이딩 플랫폼을 통하여 외표본 시뮬레이션을 적용하였다. 이를 통해 큰 규모의 VKOSPI Refined Composite Multiscale Entropy 지표변동은 특히 위험회피도 조정국면에서 평균회귀매매전략 (Mean Reversion Trades)의 로직으로 해석되었을 때 양(陽)의 주가지수대비 초과수익률을 실현할 기회에 대한 경험적 증거를 확인할 수 있었다. 이어 VKOSPI Refined Composite Multiscale Entropy 지표의 각각의 매매신호 효율성에 대한 평가를 통해 위험선호도의 하락, 상승 및 정체기간을 포괄하여 주가지수 벤치마크 성과를 초과할 수 있는 알고리즘매매의 플랫폼을 개발하는 연구가 수행되었다. 본 연구는 (1) 2003년부터 2007년말까지를 위험회피도 하락 및 양(陽)의 주가지수수익률국면, (2) 2008년부터 2011년말까지를 위험회피도 상승 및 지수수익률 변동성 확대국면 및 (3) 2012년부터 본 연구데이터의 마지막 기간인 2015년 5월29일 (영업일 기준)까지 미미한 주가지수수익률을 기록한 위험회피도 조정국면으로 연구 대상 기간을 대 분류한 후, VKOSPI지수 분석을 통하여 위험회피도 국면별 비대칭성분석 및 고유의 알고리즘매매 플랫폼을 통한 동적자산배분 전략의 수행하였다. 변동성 지수를 통해 추출된 VKOSPI Refined Composite Multiscale Entropy 기반 매매신호를 바탕으로 한국 주식시장의 변동성지표의 지수수익률간 비대칭성에 기반한 주가지수 벤치마크 수익률을 초과하는 주가지수선물 매매전략을 통해 새로 만든 Entropy 기반 내재변동성 지표의 안정성 및 활용도를 검증한 결과, 지수변동성이 낮고 일정한 최근의 시장상황에서 평균회귀전략 투자지표로서 활용되었을 때 가장 효율적인 것으로 평가되었다. For the KOSPI200 Index (“Index”), a well-known negative and statistically significant relationship exists between the returns of the Index and VKOSPI, the official model-free implied volatility index. Our primary research purpose is to test VKOSPI as an informative and meaningful trading indicator and to generate some timely trading signals. VKOSPI Refined Composite Multiscale Entropy (“VKOSPI RCMSE” or “RCMSE”) as an alternative complexity indicator was derived from the VKOSPI time series. Both long and short positions triggered by large changes in the RCMSE and the trading strategies are evaluated in terms of their ability to generate alpha through an algorithmic trading platform that will outperform the index benchmark in steady risk aversion regime. There is some empirical evidence for expecting opportunities for positive future excess and risk-adjusted returns for long and short positions triggered by large movements in the RCMSE. This finding is more prominent during the periods of steady risk aversions. Trading strategy is tested on the data period from Jan 2, 2003 to May 29, 2015. The time-varying return-volatility relation is used to implement a set of dynamic asset allocation strategies by analyzing the RCMSE with its corresponding Index. With asymmetric volatility phenomenon in the Korean stock market, selected benchmark-outperforming dynamic asset allocation strategies are developed by processing meaningful signals from RCMSE indicator on the Index Futures.

응급실로 내원한 급성 호중구 감소성 소장 결장염(Typhlitis) 1례

김향숙,정윤석,조준필 대한응급의학회 1999 대한응급의학회지 Vol.10 No.4

Typhlitis or neutropenic enterocolitis is a life-threatening, necrotizing process of the cecum whose incidence is increasing. Typhlitis presents as fever, abdominal pain, and diarrhea in neutropenic patients. As the incidence of typhlitis increases, emergency physicians must be aware of this rapidly progressive and potentially fatal disease. The definitive management of typhlitis is controversial. The most prudent course for the emergency physician is to initiate aggressive medical management early in the ED. We describe a 25-year-old man with severe neutropenia presented to the emergency department with fever, abdominal pain, diarrhea that began 2days earlier. Abdominal computerized tomography(CT) demonstrated diffuse concentric thickening of the cecal wall, intramural edema, inflammatory bowel changes but no free air and abscess formation. He was recovered by early diagnosis and aggressive medical therapy. We report a case of typhlitis with literature reviews.

Characterization of Lactic Acid Bacteria Isolated from Sauce-type Kimchi

Jung, Suk-Hee,Park, Joung-Whan,Cho, Il-Jae,Lee, Nam-Keun,Yeo, In-Cheol,Kim, Byung-Yong,Kim, Hye-Kyung,Hahm, Young-Tae The Korean Society of Food Science and Nutrition 2012 Preventive Nutrition and Food Science Vol.17 No.3

This study was carried out to investigate the isolation and characterization of lactic acid bacteria (LAB) from naturally fermented sauce-type kimchi. Sauce-type kimchi was prepared with fresh, chopped ingredients (Korean cabbage, radish, garlic, ginger, green onion, and red pepper). The two isolated bacteria from sauce-type kimchi were identified as Pediococcus pentosaceus and Lactobacillus brevis by 16S rDNA sequencing and tentatively named Pediococcus sp. IJ-K1 and Lactobacillus sp. IJ-K2, respectively. Pediococcus sp. IJ-K1 was isolated from the early and middle fermentation stages of sauce-type kimchi whereas Lactobacillus sp. IJ-K2 was isolated from the late fermentation stage. The resistance of Pediococcus sp. IJ-K1 and Lactobacillus sp. IJ-K2 to artificial gastric and bile acids led to bacterial survival rates that were 100% and 84.21%, respectively.

A Rapidly Progressing Bladder Transitional Cell Carcinoma with Sarcomatoid Deferrentiation

Hyung Suk Kim,Han Soo Chung,In-Chang Cho,Kang Su Cho,Jae Young Joung,Ho Kyung Seo,Jinsoo Chung,Weon Seo Park,Kang Hyun Lee 대한비뇨기종양학회 2010 대한비뇨기종양학회지 Vol.8 No.3

Bladder transitional cell carcinoma (TCC) accompanied with a sarcomatoid differentiation is very rarely developed and is known to have a poor prognosis due to rapid tumor growth rate. We report a case of a sarcomatoid variant bladder TCC that is developed with superficial urothelial bladder cancer in the beginning, but actually progress beyond the muscle layer after sarcomatoid differentiation although mucosal lesion is not identified by cystoscopy at outpatient clinic.

Differences in Brain Metabolite Profiles Between Normothermia and Hypothermia

Sohn Suk Ho,Chae Sihyun,Choi Jae Woong,Nam Karam,Cho Youn Joung,Cho Joo-Youn,Hwang Ho Young 대한의학회 2024 Journal of Korean medical science Vol.39 No.7

Background: This study evaluated the difference in brain metabolite profiles between normothermia and hypothermia reaching 25°C in humans in vivo. Methods: Thirteen patients who underwent thoracic aorta surgery under moderate hypothermia were prospectively enrolled. Plasma samples were collected simultaneously from the arteries and veins to estimate metabolite uptake or release. Targeted metabolomics based on liquid chromatographic mass spectrometry and direct flow injection were performed, and changes in the profiles of respective metabolites from normothermia to hypothermia were compared. The ratios of metabolite concentrations in venous blood samples to those in arterial blood samples (V/A ratios) were calculated, and log2 transformation of the ratios [log2(V/A)] was performed for comparison between the temperature groups. Results: Targeted metabolomics were performed for 140 metabolites, including 20 amino acids, 13 biogenic amines, 10 acylcarnitines, 82 glycerophospholipids, 14 sphingomyelins, and 1 hexose. Of the 140 metabolites analyzed, 137 metabolites were released from the brain in normothermia, and the release of 132 of these 137 metabolites was decreased in hypothermia. Two metabolites (dopamine and hexose) showed constant release from the brain in hypothermia, and 3 metabolites (2 glycophospholipids and 1 sphingomyelin) showed conversion from release to uptake in hypothermia. Glutamic acid demonstrated a distinct brain metabolism in that it was taken up by the brain in normothermia, and the uptake was increased in hypothermia. Conclusion: Targeted metabolomics demonstrated various degrees of changes in the release of metabolites by the hypothermic brain. The release of most metabolites was decreased in hypothermia, whereas glutamic acid showed a distinct brain metabolism.

Clinical features and surgical outcomes of complete transposition of the great arteries

Hong, Suk Jin,Choi, Hee Joung,Kim, Yeo Hyang,Hyun, Myung Chul,Lee, Sang Bum,Cho, Joon Yong The Korean Pediatric Society 2012 Clinical and Experimental Pediatrics (CEP) Vol.55 No.10

Purpose: This single-center study aimed to assess the clinical features and surgical approaches and outcomes of complete transposition of the great arteries (TGA). Methods: TGA patients who had undergone surgical correction at the Kyungpook National University Hospital from January 2000 to December 2010, were retrospectively evaluated for patient characteristics, clinical manifestation, preoperative management, intraoperative findings, postoperative progress, and follow-up status. Results: Twenty-eight patients (17 boys and 11 girls, mean age=$10.6{\pm}21.5$ days) were included and were categorized as follows: group I, TGA with intact ventricular septum (n=13); group II, TGA with ventricular septal defect (VSD, n=12); and group III, TGA/VSD with pulmonary stenosis (n=3). Group I underwent the most intensive preoperative management (balloon atrial septostomy and prostaglandin E1 medication). Group II showed the highest incidence of heart failure (P<0.05). Usual and unusual coronary anatomy patterns were observed in 20 (71%) and 8 patients, respectively. Arterial and half-turned truncal switch operations were performed in 25 and 3 patients (Group III), respectively. Postoperative complications included cardiac arrhythmias (8 patients), central nervous system complications (3 patients), acute renal failure (1 patient), infections (3 patients), and cardiac tamponade (1 patient), and no statistically significant difference was observed between the groups. Group II showed the mildest aortic regurgitation on follow-up echocardiograms (P<0.05). One patient underwent reoperation, and 1 died. The overall mortality rate was 4%. Conclusion: Our study showed favorable results in all the groups and no significant difference in postoperative complication, reoperation, and mortality among the groups. However, our results were inadequate to evaluate the risk factors for reoperation and mortality owing to the small number of patients and short follow-up duration.