Cash Flow Anomalies Associated with Business Conditions in Korean Stock Market

Bohyun Yoon,Sam-Ho Son 한국재무학회 2014 한국재무학회 학술대회 Vol.2014 No.05

Purpose – Many literature reports that returns on hedge portfolios which eliminate particular sort of risks are abnormal in the perspective of the traditional asset pricing models. This study examines the pervasiveness of anomalous returns conditioned on business cycle and size groups. Research design, data, and methodology – We use the KOSPI and KOSDAQ market data from July 1991 to December 2013. To examine the pervasiveness of anomalies, we categorize all stocks into properly-sized groups and dichotomize our sample periods into expansion and recession periods, then construct the hedge portfolios by sorting stocks depending on anomaly variables and calculate their returns. Results – The results demonstrate that four anomalies such as earnings yield, net stock issue, total asset growth, and liquidity appear pervasive across all of the size groups for the whole sample period. However, only the hedge returns of net stock issue are significant across all size groups during both expansion and recession. Conclusions – Net stock issue can be considered as an appropriate proxy for the expected growth of book equity for all size groups in recession. This finding is expected to give insights to the executors of investment industry and to the researchers who are interested in relationship between the expected growth of book equity and business cycle risk.

Corporate Social Responsibility and Information Asymmetry in the Korean Market: Implications of Chaebol Affiliates

Bohyun Yoon,Jeong-Hwan Lee 한국유통과학회 2019 The Journal of Asian Finance, Economics and Busine Vol.6 No.1

This paper examines how corporate social responsibility is related to the degree of asymmetric information in the Korean financial market. Recent theory argues that there is a negative relationship between a firm’s corporate social responsibility and its information asymmetry. To test this hypothesis, we use the environment, social and governance (ESG) score, published by the Korean Corporate Governance Service, to proxy a firm’s management practices toward socially responsible activities. In the entire sample of the Korean firms, we find contrasting results; the ESG score shows negative relationships with the price impact measure but statistically insignificant relationships with the dispersion of analyst forecasts. However, the ESG score shows negative relationships with both measures when we exclude chaebol affiliates from the sample. These findings are robust when we examine environmental, social and corporate governance scores separately. This set of results argues for the extant theory, expecting a negative relationship between a firm’s engagement in corporate social responsibility and asymmetric information. It further argues for the importance of firm characteristics in determining the influence of socially responsible activities.

국내 주식시장의 대안 인덱스 연구 : 스마트 베타를 중심으로

윤보현 ( Bohyun Yoon ),손경우 ( Kyoung-woo Sohn ),유원석 ( Won-suk Liu ) 한국파생상품학회(구 한국선물학회) 2017 선물연구 Vol.25 No.2

본 연구는 전통적 인덱스 투자전략의 대안으로써 스마트 베타전략의 유의성을 살펴 보고자 하였다. 이를 위해 이미 알려진 이례현상(anomaly) 종목을 대상으로, 다양한 비중 결정방법에 따라 최적화된 포트폴리오들의 성과를 측정, 비교, 분석하였다. 본 연구가 발견한 주요 결과는 다음과 같다. 첫째, 시가총액비중 이외의 비중으로 최적화된 포트폴리오는 효율성을 제고할 수 있는 것으로 나타났다. 둘째, 다양한 방법으로 최적화된 포트폴리오는 효율성의 제고를 가져오지만, 시장전체 종목을 대상으로 구성되는 한 이상(abonormal) 초과수익률 알파의 창출은 어려운 것으로 나타났다. 반면, 이례현상 종목만을 대상으로 최적화된 포트폴리오는 효율성 제고뿐 아니라 유의한 초과수익률 알파의 창출이 가능한 것으로 나타났다. 셋째, 이례현상 종목 대상 최적화된 포트폴리오의 성과는 공매도 제한상황에서도 유의하였다. 이러한 결과들은 자산운용업계에 중요한 함의를 제공한다. 첫째, 펀드매니저는 스마트 베타전략 포트폴리오를 벤치마크로 패시브운용하여 마켓 타이밍 등 액티브 전략 없이 트래킹만으로도 유의한 알파를 창출할 수 있다. 둘째, 펀드 매니저는 전망 및 예측과 관련된 비용 및 전망 및 예측오류에 의한 위험을 감소시킴으로써 효율성을 제고할 수 있다. Recently, due to its passive property, the smart beta has become one of the most interest topics in searching the alpha. In this paper, we attempt to show whether the smart beta strategy generate abnormal excess return, in tradition, which are known as the exclusive property of active fund. Further, we attempt to verify the key drivers of the alpha in the smart beta portfolios. For this purpose, we categorize various smart beta strategies by their scheme for asset picking and risk reduction. Then, based on our categorization, we evaluate and analyze the performance of smart beta strategy in perspective. Our empirical analyses show following results: applying alternative risk reduction scheme to traditional market index portfolio would results in enhanced efficiency; however, without combining any asset picking scheme, the performance of the smart beta portfolio seems explained by the Fama-French 3 factor. Our results lead us to conjecture that it is not the portfolio weighting scheme alone but in association with asset selection scheme that generate significant alpha in the smart beta strategy. In actual practice, our results imply that any passive fund may succeed in seeking the alpha without active strategy, thereby avoiding the risk of market timing and saving the management cost.

국내 주식시장의 스마트베타 투자수익에 관한 연구

윤보현(Bohyun Yoon),강윤식(Yun-Sik Kang),손삼호(Samho Son) 한국자료분석학회 2018 Journal of the Korean Data Analysis Society Vol.20 No.1

본 논문은 최근 본격화되고 있는 국내 스마트베타(smart beta) 투자수익의 특성을 살펴보고 해외 선진국과의 비교를 통해 바람직한 스마트베타 투자전략의 수립방향을 모색해보고자 한다. 일반적으로 스마트베타 투자는 패시브 벤치마크(passive benchmark) 대비 초과수익률을 지속적으로 제공해주는 한편 저렴한 펀드 비용과 투명성 등으로 인해 액티브 펀드(active fund)에 비해서도 상대적인 장점을 갖는 것으로 평가된다. 최근 우리나라에서도 대형 자산운용사를 중심으로 스마트베타 ETF(exchange traded funds) 투자가 성장초기단계에 들어서고 있다. 본 논문은 국내 업계에서 실용적으로 구현할 수 있는 매수전용 포트폴리오(long-only portfolio) 수익률을 검토한 결과 장부가/시가 비율, 규모, 모멘텀(momentum), 비유동성, 이익수익률, 비체계적 위험 등이 유의한 수익률을 나타냄을 확인하였다. 또한 본 논문은 이들 요인들에 대한 수익률평균전략, 매수보유전략, 적극적 포트폴리오 재조정 전략 등의 결합수익률 특성을 비교해 본 결과 변동성이 거의 일정하게 유지되는 상태에서 적극적 포트폴리오 재조정 전략의 수익률이 가장 높게 나타나는 것을 확인하였다. 이 결과는 국내 투자환경에서도 보다 신중한 검토를 통하여 더 높은 알파(alpha)를 제공하는 액티브한 배분전략(active management strategy)으로 새로운 금융상품을 구성할 수 있음을 시사한다. This paper searches for the desirable smart beta investing strategies consistent with the unique combined characteristics of the domestic risk factors. We investigated the performance characteristics of Korean long-only factor-based smart betas, and found significant excess returns of six factors, such as book-to-market ratio, size, momentum, illiquidity, profitability and unsystematic risk factors. We found that the performance of multiple combined factor portfolio strategies exceed the single factor strategies. Specifically, we compared the performances of multi-factor based smart beta strategies such as average of six factors, buy and hold, rebalancing 1 year, and dynamic rebalancing strategies. We found that the return of dynamic rebalancing strategy is highest among the others while the volatilities stay at a similar level. As a result, making new products which gives higher alpha becomes possible in Korean stock market. In developing such a product, there need to understand the specific characteristics of combined risk factor more correctly. The various combination strategies should be based on these understandings in Korean stock market.

여행운송업에서의 사회적 책임의 효과

윤보현(Yoon, Bohyun),문준호(Moon, Joonho),강윤식(Kang, Yunsik) 한국관광레저학회 2018 관광레저연구 Vol.30 No.9

해양 미생물을 활용한 생명과학 및 생명공학 기술 개발

윤용준(Yongjoon Yoon),윤보현(Bohyun Yun),황성민(Bohyun Yun),문기환(Ki Hwan Moon) 한국생명과학회 2023 생명과학회지 Vol.33 No.7

바다는 지구 표면의 70% 이상을 차지하고 있으며, 그 자체가 대부분 탐사되지 않은 미지와 기회의 공간으로 제시되고 있다. 특히, 우리나라는 삼면이 바다로 둘러싸인 반도로 해양 연구의 중요성이 강조되고 있다. 매우 복잡하고 다양한 환경을 가지고 있는 해양은 막대한 생물학적 다양성을 보이고 있으며 미생물학적 측면에서도 해양 환경은 다양하고 극단적인 온도, 압력, 일사량, 염분, pH 등을 가지고 있어 생태학적으로 특이한 서식처를 제공한다. 이로 인해 육상과는 달리 계통분류학적으로 매우 다르며, 다양한 미생물들이 서식하나 그 다양성, 분리, 배양 그리고 이들이 생산해 내는 2차 대사산물 등에 대한 연구는 아직도 미진한 상황이다. 1990년대까지도 거의 연구되지 않던 해양 환경 자생 미생물의 생리활성물질에 대한 연구는 2000년대 들어 해양 방선균이 생산해 내는 천연물에 대한 연구가 가속화 되기 시작했다. 이후, 박테리아, 고세균, 조류 등을 활용한 항균제, 항암제, 항산화제, 항염증제 등과 같은 의약품 개발 분야 뿐만 아니라 및 바이오 플라스틱 생산, 바이오 연료 생산, 이산화탄소 포집, 생균제 발굴 및 개발 등의 다양한 산업분야에서 해양 미생물을 활용한 연구가 가속화 되고 있는 실정이다. 본 총설에서는 해양미생물을 활용한 생명과학 및 생명공학 기술 분야의 연구 성과 및 최신 동향을 소개하고자 한다. 이를 통해 독자들이 의약소재 개발 외 제반 천연물 관련 분야의 기반 및 응용 연구의 중요성을 인식하고 미래 해양 유래 소재를 이용한 바이오 연구 개발의 최적화 및 실용화 연구에 적극 도움이 되길 기대한다. The ocean accounts for over 70% of the Earth’s surface and is a space of largely unexplored unknowns and opportunities. Korea is a peninsula surrounded by the sea on three sides, emphasizing the importance of marine research. The ocean has an extremely complex environment with immense biological diversity. In terms of microbiology, the marine environment has varying factors like extreme temperature, pressure, solar radiation, salt concentration, and pH, providing ecologically unique habitats. Due to this variety, marine organisms have very different phylogenetic classifications compared with terrestrial organisms. Although various microorganisms inhabit the ocean, studies on the diversity, isolation, and cultivation of marine microorganisms and the secondary metabolites they produce are still insufficient. Research on bioactive substances from marine microorganisms, which were rarely studied until the 1990s, has accelerated in terms of natural products from marine Actinomycetes since the 2000s. Since then, industries for bioplastic and biofuel production, carbon dioxide capture, probiotics, and pharmaceutical discovery and development of antibacterial, anticancer, antioxidant, and anti-inflammatory drugs using bacteria, archaea, and algae have significantly grown. In this review, we introduce current research findings and the latest trends in life science and biotechnology using marine microorganisms. Through this article, we hope to create consumer awareness of the importance of basic and applied research in various natural product-related discovery fields other than conventional pharmaceutical drug discovery. The article aims to suggest pathways that may boost research on the optimization and application of future marine-derived materials.

Hemorheological Alteration in Patients Clinically Diagnosed with Chronic Liver Diseases

Jang, Bohyun,Han, Ji Won,Sung, Pil Soo,Jang, Jeong Won,Bae, Si Hyun,Choi, Jong Young,Cho, Young I,Yoon, Seung Kew The Korean Academy of Medical Sciences 2016 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.31 No.12

<P>Since liver function is changed by chronic liver diseases, chronic liver disease can lead to different hemorheological alterations during the course of the progression. This study aims to compare alterations in whole blood viscosity in patients with chronic liver disease, focusing on the gender effect. Chronic liver diseases were classified into three categories by patient’s history, serologic markers, and radiologic findings: nonalcoholic fatty liver disease (NAFLD) (n = 63), chronic viral hepatitis B and C (n = 50), and liver cirrhosis (LC) (n = 35). Whole blood viscosity was measured by automated scanning capillary tube viscometer, while liver stiffness was measured by transient elastography using FibroScan®. Both systolic and diastolic whole blood viscosities were significantly lower in patients with LC than NAFLD and chronic viral hepatitis (<I>P</I> < 0.001) in male patients, but not in female patients. In correlation analysis, there were inverse relationships between both systolic and diastolic whole blood viscosity and liver stiffness (systolic: <I>r</I> = −0.25, diastolic: <I>r</I> = −0.22). Whole blood viscosity was significantly lower in male patients with LC than NAFLD or chronic viral hepatitis. Our data suggest that whole blood viscosity test can become a useful tool for classifying chronic liver disease and determining the prognosis for different types of chronic liver diseases.</P>

Promyelocytic Blast Phase of Chronic Myeloid Leukemia, BCR-ABL1 -Positive: Points to be Considered at Diagnosis

Kim Bohyun,Chi Hyun Young,Yoon Young Ahn,Choi Young-Jin 대한진단검사의학회 2021 Annals of Laboratory Medicine Vol.41 No.3

Total Synthesis of Isohericerin, Isohericenone, and Erinacerin A: Development of a Copper-Catalyzed Methylboronation of Terminal Alkynes

Mun, Bohyun,Kim, Sangyong,Yoon, Hongju,Kim, Ki Hyun,Lee, Yunmi American Chemical Society etc. 2017 Journal of organic chemistry Vol.82 No.12

<P>Efficient and concise approaches for the synthesis of three bioactive natural products, isohericerin, isohericenone, and erinacerin A, are described in this paper. The key reactions employed include a Mannich reaction with commercially available hydroxybenzoate and subsequent one pot lactamization to afford the common precursor isoindolinone in 3 steps and a Suzuki-Miyaura coupling reaction to connect geranyl side chains to the isoindolinone core. In addition, the mild and efficient synthesis of the CS'-oxidized geranyl side unit of isohericenone is enabled by developing a highly regioselective and efficient method for the Cu-catalyzed methylboronation of functionalized terminal alkynes.</P>

Incidence-Based versus Prevalence-Based Approaches on Measuring Disability-Adjusted Life Years for Injury

Park, Bohyun,Park, Bomi,Lee, Won Kyung,Kim, Young-Eun,Yoon, Seok-Jun,Park, Hyesook The Korean Academy of Medical Sciences 2019 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.34 No.11

<P><B>Background</B></P><P>Injury represents an important aspect of disease that affects everyone at some point in their lives. To better understand and prevent these injuries, various analytical methods have been developed to assess both the magnitude and features of injury burden. In this study, we attempted to estimate the injury burden of Korea in 2014 by comparing the prevalence-based approach used by the Global Burden of Diseases (GBD) team and the World Health Organization against an alternative incidence-based approach, and to assess the different implications of these measurements.</P><P><B>Methods</B></P><P>The 10th Korean National Hospital Discharge survey data and causes of death statistics in 2014 were used as data sources. Years of life lost (YLL), years lived with disability (YLD) and disability-adjusted life years (DALYs) were calculated using both the incidence- and prevalence-based approaches. The Korean Classification of Diseases (KCD) version 5 diagnostic codes were used to classify the mechanism of injury.</P><P><B>Results</B></P><P>The prevalence-based injury burden tended to be higher (1,670,229 DALYs) than the incidence-based injury burden (1,544,467 DALYs). The elderly population exhibited a higher prevalence-based YLD and DALY relative to incidence-based outcomes. In order of significance, the three most common causes of injury as calculated using an incidence-based approach were road injury, fall, and self-harm, compared with a prevalence-based method, which identified self-harm, road injury, and falls as the most common injuries.</P><P><B>Conclusion</B></P><P>An appropriate prevention program is needed for injuries with potential to cause long-lasting morbidity. Accordingly, a tailored injury-prevention strategy should be developed for each high-risk group.</P>