• Korean Journal of Logic
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• v.6 no.2
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• pp.23-48
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• 2003

"왜"로 시작하는 질문들의 성격은 워낙 다양해서, 우리는 "왜" 질문들 모두에 공통적으로 적용되는 흥미로운 이야기를 할 수 있으리라는 것에 대해 회의적이 되기가 쉽다. 이 논문에서 필자는 그런 우려에 맞서, "왜" 질문들이 공동적으로 가진 화용론적, 의미론적 성격들이 존재한다고 주장하면서 그것들이 무엇인지를 논의한다. 필자는 한 의문문의 의미는 그것에 대한 적합한 서술문 대답들의 진리 조건들의 집합이라는 일반적 이론에 입각해서 "왜" 의문문에 대한 적합한 대답들이 갖추어야 할 조건들이 무엇인지 그리고 그 적합한 대답들이 가진 진리 조건이 무엇인지에 대한 이론을 제시한다. 이와 같은 이론을 발전시키는 과정에서 필자는, 어떤 "왜" 의문문이 특정 맥락에서 보다 더 자연스럽게 제기되는 이유가 무엇인가 다양한 종류의 것들 이유, 원이, 근거 등-을 질문한다고 여겨지는 "왜" 의문문들이 어떻게 이 이론에서 통합적인 방식으로 이해될 수 있는가 등의 여러 문제들에 대한 대답을 시도한다.

• The Korean Journal of Applied Statistics
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• v.16 no.1
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• pp.101-115
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• 2003

Lately there has been much theoretical and applied interest in linear models with non-normal heavy tailed error distributions. Starting Zellner(1976)'s study, many authors have explored the consequences of non-normality and heavy-tailed error distributions. We consider hierarchical models including selection models under a skewed heavy-tailed e..o. distribution proposed originally by Chen, Dey and Shao(1999) and Branco and Dey(2001) with Dirichlet process prior(Ferguson, 1973) in order to use a meta-analysis. A general calss of skewed elliptical distribution is reviewed and developed. Also, we consider the detail computational scheme under skew normal and skew t distribution using MCMC method. Finally, we introduce one example from Johnson(1993)'s real data and apply our proposed methodology.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.4
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• pp.209-220
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• 2019

Even though the scale of hard structures for beach stabilization should carefully be determined such that these structures do not interrupt the great yearly circulation process of beach sediment in which the self-healing ability of natural beach takes places, massive hard structures such as the submerged breakwater of wide-width are frequently deployed as the beach stabilization measures. On this rationale, asymmetric ripple mat by Irie et al. (1994) can be the alternatives for beach stabilization due to its small scale to replace the preferred submerged breaker of wide-width. The effectiveness of asymmetric ripple mat is determined by how effectively the vortices enforced at the contraction part of flow area over the mat traps the sediment moving toward the offshore by the run-down. In order to verify this hypothesis, we carry out the numerical simulations based on the Navier-Stokes equation and the physically-based morphology model. Numerical results show that the asymmetric ripple mat effectively capture the sediment by forced vortex enforced at the apex of asymmetric ripple mat, and bring these trapped sediments back to the beach, which has been regarded to be the driving mechanism of beach stabilization effect of asymmetric ripple mat.

• 건강소식
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• v.34 no.5
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• pp.14-15
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• 2010

신나게 놀이터에서 놀고 들어온 우리 아이, 같이 높던 다른집 아이는 멀쩡한데 왜 우리 아이만 코를 훌쩍일까? 밥먹으라고 식탁 앞에 앉혀놔도 왜 밥은 안 먹고 짜증만 내는 걸까? 다른 아이에 비해 우리 아이 키는 왜 이리 작은 걸까? 걸핏하면 식은땀에 아토피에, 왜 우리 아이만 이렇게 허약할까? 지금 당신의 아이가 이러하다면 아이의 면역력 체계에 문제가 없는지 진단해 봐야 한다.

• The Korean Journal of Financial Management
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• v.25 no.4
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• pp.79-116
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• 2008

This paper examines and estimates GARCH-VaR models (RiskMetrics, GARCH, IGARCH, GJR and APARCH) with three different distributions such as Gaussian normal, Student-t, Skewness Student-t Distribution using the daily price data from Korean Stock Market during Jan. 1, 1980-Sept. 30, 2004. It also compares them. In-sample test, this finds that for all confidence level as $90%{\sim}99.9%$, the performance and accuracy of IGARCH with ${\lambda}=0.87$ and skewness Student-t distribution are superior to other models and distributions in long position, but GARCH and GJR with Skewness Student-t distribution in short position. For above 99% confidence level, the performance and accuracy of IGARCH with ${\lambda}=0.87$ in both long and short positions are superior to other models and distributions, but Skewness Student-t distribution for long position and Student-t distribution for short position are more accuracy and superior to other distributions. In-out-of sample test, these results also confirm the evidences that the above findings are consistent as well.

• Journal of the Korean Data and Information Science Society
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• v.28 no.5
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• pp.959-970
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• 2017

In this study, we propose bivariate skewness and kurtosis statistics and suggest a surface plot that can visually implement bivariate data containing the correlation coefficient. The skewness statistic is expressed in the form of a paired real values because this represents the skewed directions and degrees of the bivariate random sample. The kurtosis has a positive value which can determine how thick the tail part of the data is compared to the bivariate normal distribution. Moreover, the surface plot implements bivariate data based on the quantile vectors. Skewness and kurtosis are obtained and surface plots are explored for various types of bivariate data. With these results, it has been found that the values of the skewness and kurtosis reflect the characteristics of the bivariate data implemented by the surface plots. Therefore, the skewness, kurtosis and surface plot proposed in this paper could be used as one of valuable descriptive statistical methods for analyzing bivariate distributions.

• Korea Information Processing Society Review
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• v.10 no.2
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• pp.122-137
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• 2003

• The Korean Journal of Applied Statistics
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• v.17 no.3
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• pp.507-518
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• 2004

Malkovich & Afifi (1973) generalized the univariate skewness and kurtosis to test a hypothesis of multivariate normality by use of the union-intersection principle. However these statistics are hard to compute for high dimensions. We propose the approximate statistics to them, which are practical for a high dimensional data set. We also compare the proposed statistics to Mardia(1970)'s multivariate skewness and kurtosis by a Monte Carlo study.

• The Korean Journal of Applied Statistics
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• v.29 no.1
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• pp.41-59
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• 2016

There have been continuous improvements in human life expectancy. Life expectancy is as a key factor in an aging population and can wreak severe damage on the financial integrity of pension providers. Hence, the projection of the accurate future mortality is a critical point to prevent possible losses to pension providers. However, improvements in future mortality would be overestimated by a typical mortality projection method using the Lee-Carter model since it underestimates the mortality index ${\kappa}_t$. This paper suggests a mortality projection based on the projection of the skewness of the mortality versus the typical mortality projection of the Lee-Carter model based on the projection of the mortality index, ${\kappa}_t$. The paper shows how to indirectly estimate future t trend with the skewness of the mortality and compares the results under each estimation method of the mortality index, ${\kappa}_t$. The analysis of the results shows that mortality projection based on the skewness presents less improved mortality at an elderly ages than the original projection.

• 식품문화 한맛한얼
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• v.3 no.3
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• pp.302-305
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• 2010

보리밥이 왜 쌀밥보다 건강에 좋을까? 보리를 먹으면 왜 방귀가 나올까? 이 글에서는 보리에 관한 여러 질문에 대한 해답과 함께 보리의 영양학적 특성 및 효능에 대해 살펴보기로 한다.