• 한국정보통신학회논문지
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• 제26권10호
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• pp.1423-1431
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• 2022

블랙숄즈모형에서 옵션가격을 결정하는 변수 중 기초자산의 변동성은 현재 시점에서는 알 수 없고, 미래시점에 실현된 변동성을 사후에야 알 수 있다. 하지만 옵션이 거래되는 시장에서 관찰되는 가격이 있기 때문에 가격에 내재된 변동성을 역으로 산출한 내재변동성은 현재 시점에 구할 수 있다. 내재변동성을 구하기 위해서는 옵션가격과, 블랙숄즈 모형의 변동성을 제외한 옵션가격결정변수인 기초자산가격, 무위험이자율, 배당률, 행사가격, 잔존기간이 필요하다. 블랙숄즈모형의 변동성은 고정된 상수이나, 내재변동성 산출시 행사가격에 따라 변동성이 다르게 산출되는 변동성스마일현상을 보이기도 한다. 따라서 내재변동성 산출시 옵션 단일 종목이 아닌 시장전반의 변동성을 감안하는 것이 필요하다고 판단하여 본 연구에서는 V-KOSPI지수도 설명변수로 추가하였다. 머신러닝기법 중 지도학습방법을 사용하였으며, Linear Regression 계열, Tree 계열, SVR과 KNN 알고리즘 및 딥뉴럴네트워크로 학습 및 예측하였다. Training성능은 Decision Tree모형이 99.9%로 가장 높았고 Test성능은 Random Forest 알고리즘이 96.9%로 가장 높았다.

• Management Science and Financial Engineering
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• 제20권1호
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• pp.21-26
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• 2014

A lot of researches have been conducted to estimate the volatility smile effect shown in the option market. This paper proposes a method to approximate an implied volatility function, given noisy real market option data. To construct an implied volatility function, we use Gaussian Processes (GPs). Their output values are implied volatilities while moneyness values (the ratios of strike price to underlying asset price) and time to maturities are as their input values. To show the performances of our proposed method, we conduct experimental simulations with Korean Equity-Linked Warrant (ELW) market data as well as toy data.

• Journal of the Korean Data and Information Science Society
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• 제22권3호
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• pp.589-596
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• 2011

The conditional autoregressive value at risk (CAViaR) model is useful for risk management, which does not require the assumption that the conditional distribution does not vary over time but the volatility does. But it does not provide volatility forecasts, which are needed for several important applications such as option pricing and portfolio management. For a variety of probability distributions, it is known that there is a constant relationship between the standard deviation and the distance between symmetric quantiles in the tails of the distribution. This inspires us to use a support vector quantile regression (SVQR) for volatility forecasts with the distance between CAViaR forecasts of symmetric quantiles. Simulated example and real example are provided to indicate the usefulness of proposed forecasting method for volatility.

• 재무관리논총
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• 제3권1호
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• pp.213-231
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• 1996

In this study we conduct a specification test of at-the-money option volatility. Results show that the implied volatility estimate recovered from the Black-Scholes European option pricing model is nearly indistinguishable from the implied volatility estimate obtained from the Barone-Adesi and Whaley's American option pricing model. This study also investigates whether the use of Black-Scholes implied volatility estimates in American put pricing model significantly affect the prediction the prediction of American put option prices. Results show that, at long as the possibility of early exercise is carefully controlled in calculation of implied volatilities prediction of American put prices is not significantly distorted. This suggests that at-the-money option implied volatility estimates are robust across option pricing model.

• Journal of Construction Engineering and Project Management
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• 제7권3호
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• pp.15-25
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• 2017

The existence of material price volatility in construction projects puts forward substantial risks for all parties involved. Depending on the parties involved in the project, type of contracts, and state of the market various risk management strategies are practiced by contracting parties to manage project risks related to price volatility. Unfortunately, in many cases companies fail to select an adequate approach to better manage volatilities of material prices due to the lack of a decision support system to aid in the selection of an appropriate strategy based on the project characteristics. The aim of this study is to identify critical project factors and align them to documented strategies to manage price volatility based on an extensive literature review and industry interviews. This study found Integrated Project Delivery (IPD) as the ideal strategy with respect to project duration; quantitative risk management methods with respect to the cost; and Price Adjustment Clauses (PAC) with respect to the risk allocation, as the top price volatility management strategies.

• East Asian Economic Review
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• 제17권3호
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• pp.311-332
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• 2013

This paper examines the effect of initial margin requirements on long-run and short-run volatilities in the Japanese stock market using the Component GARCH model. Our empirical results show that when we do not divide the margin requirement into positive and negative changes, increasing margin requirement is effective for reducing long-run volatility, while not effective in short-run volatility. However, separating the positive and negative changes in margin requirements reveals the fact that the negative changes in margin requirements decrease long-run volatilities, while the higher margin requirements increase short-run volatilities in the Japanese stock market. This suggests that if the Japanese financial authorities intend to increase margin level to reduce volatility, unexpectedly, short-run volatility would be even higher.

• 응용통계연구
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• 제33권6호
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• pp.713-722
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• 2020

본 논문에서는 금융시계열의 특징인 비대칭 변동성을 연구하고 있다. 멱변환을 동시에 고려한 멱변환-비대칭 GARCH 모형을 소개하고 있다. 변동성이 비정상인 모형을 다루고 있으며 오차항으로 표준정규분포와 더불어 표준화 t-분포도 고려하여 변동성 정상/비정상 조건을 제시하고 있다. 미국 주가 시계열인 다우지수 적용사례를 예시하였다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제27권3호
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• pp.180-193
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• 2023

Approximating the implied volatilities and estimating the model parameters are important topics in quantitative finance. This study proposes an approximation formula for short-maturity near-the-money implied volatilities in stochastic volatility models. A general second-order nonlinear PDE for implied volatility is derived in terms of time-to-maturity and log-moneyness from the Feyman-Kac formula. Using regularity conditions and the Taylor expansion, an approximation formula for implied volatility is obtained for short-maturity nearthe-money call options in two stochastic volatility models: Heston model and SABR model. In addition, we proposed a novel numerical method to estimate model parameters. This method reduces the number of model parameters that should be estimated. Generating sample data on log-moneyness, time-to-maturity, and implied volatility, we estimate the model parameters fitting the sample data in the above two models. Our method provides parameter estimates that are close to true values.

• 아태비즈니스연구
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• 제15권1호
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• pp.1-14
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• 2024

Purpose - We investigate whether a potential missing pricing factor plays a significant role in the idiosyncratic volatility puzzle. Design/methodology/approach - We theoretically show how a missing pricing factor can affect the idiosyncratic volatility puzzle, and also show how to get around the problem empirically. We adopt the Fama-French five factor model for the estimation of the idiosyncratic risk and use randomly constructed portfolios as test assets. Findings - We find that a missing factor does not drive the idiosyncratic volatility puzzle. Thus, we conclude that the idiosyncratic volatility does affect the risk premium of its stock. Research implications or Originality - The Fama-French five factor model does a pretty good job in explaining the risk premiums of stocks, and it can be used to reliably estimate idiosyncratic risk of stocks.

• 한국산학기술학회논문지
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• 제15권1호
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• pp.189-195
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• 2014

본 연구에서는 코스피200 주식시장, 선물시장, 옵션시장 등의 투자자별 거래량을 동시에 고려하여 각 시장의 변동성에 어떤 영향을 미치는지를 알아보았다. 실증분석결과를 요약하면 다음과 같다. 첫째, 주식시장 및 선물시장의 변동성은 다른 시장의 거래정보에 의해서도 영향을 받는다. 이는 한 시장의 변동성이 다른 시장의 거래정보에 의해서 영향을 받는다는 것이다. 변동성에 대한 거래정보의 교차시장효과(cross-market effect)가 존재함을 의미한다. 둘째, 옵션시장의 변동성은 투자자들의 거래정보로는 설명되지 않는다. 이는 옵션시장의 변동성이 한 달 미래의 기초자산의 변동성에 대한 기대를 반영하고 있기 때문이다. 셋째, 전반적으로 개인의 경우 변동성을 증가시키는 것으로 나타났으며, 기관과 외국인 투자자의 경우 변동성을 감소시키는 것으로 나타났다. 이러한 연구결과는 변동성이 주요한 변수로 작용하는 영역인 투자전략, 위험관리, 금융시장 안정화방안 등에 활용될 수 있을 것이다.