• Title/Summary/Keyword: student-t

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Long Memory Properties in the Volatility of Australian Financial Markets: A VaR Approach (호주 금융시장 변동성의 장기기억 특성: VaR 접근법)

  • Kang, Sang-Hoon;Yoon, Seong-Min
    • International Area Studies Review
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    • v.12 no.2
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    • pp.3-26
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    • 2008
  • This article investigates the usefulness of the skewed Student-t distribution in modeling the long memory volatility property that might be present in the daily returns of two Australian financial series; the ASX200 stock index and AUD/USD exchange rate. For this purpose we assess the performance of FIGARCH and FIAPARCH Value-at-Risk (VaR) models based on the normal, Student-t, and skewed Student-t distribution innovations. Our results support the argument that the skewed Student-t distribution models produce more accurate VaR estimates of Australian financial markets than the normal and Student-t distribution models. Thus, consideration of skewness and excess kurtosis in asset return distributions provides appropriate criteria for model selection in the context of long memory volatility models in Australian stock and foreign exchange markets.

Comparing Among GARCH-VaR Models and Distributions from Korean Stock Market (KOSPI) :Focusing on Long and Short Positions (한국 KOSPI시장의 GARCH-VaR 측정모형 및 분포간 성과평가에 관한 연구:롱 및 숏 포지션 전략을 중심으로)

  • Son, Pan-Do
    • 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.

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Value-at-Risk Models in Crude Oil Markets (원유시장 분석을 위한 VaR 모형)

  • Kang, Sang Hoon;Yoon, Seong Min
    • Environmental and Resource Economics Review
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    • v.16 no.4
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    • pp.947-978
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    • 2007
  • In this paper, we investigated a Value-at-Risk approach to the volatility of two crude oil markets (Brent and Dubai). We also assessed the performance of various VaR models (RiskMetrics, GARCH, IGARCH and FIGARCH models) with the normal and skewed Student-t distribution innovations. The FIGARCH model outperforms the GARCH and IGARCH models in capturing the long memory property in the volatility of crude oil markets returns. This implies that the long memory property is prevalent in the volatility of crude oil returns. In addition, from the results of VaR analysis, the FIGARCH model with the skewed Student-t distribution innovation predicts critical loss more accurately than other models with the normal distribution innovation for both long and short positions. This finding indicates that the skewed Student-t distribution innovation is better for modeling the skewness and excess kurtosis in the distribution of crude oil returns. Overall, these findings might improve the measurement of the dynamics of crude oil prices and provide an accurate estimation of VaR for buyers and sellers in crude oil markets.

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A Study on The Influence between Self-directed Learning and Nursing Student's Satisfaction of Clinical Practice (자기주도적 학습능력이 간호학생의 임상실습만족도에 미치는 영향)

  • Kim, Kyeong-Ah
    • Journal of Korean Clinical Health Science
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    • v.4 no.2
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    • pp.571-581
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    • 2016
  • Purpose. This study was to identify the relationship between self-directed learning and nursing student's satisfaction of clinical practice. Methods. This study was designed to measure the level of satisfaction according to the contents, guidance, environment, time, and the evaluation of clinical practice. Two hundred thirty-one nursing student from baccalaureate program in H-gun was sampled. A scale consisting of 75 questions, developed by the researcher, was used to gather data from September 14 through 27, 2012. The data was analyzed by descriptive statistics, paired t-test, pearson correlation, and multiple linear regression using the SPSS WIN 18.0 program. Results. The results were summarized : Self-directed learning didn't show a significant different by grade(t=0.83, p=.934). Nursing student's satisfaction of clinical practice didn't show a significant different by grade(t=0.26, p=.798). The relationship between self-directed learning correlated with the degree of nursing student's satisfaction in clinical practice(r=.44, p<.001). The factors of self-directed learning described nursing student's satisfaction of clinical practice as $R^2$=.215(F=9.858, p<.001). Conclusions. It was found that a higher degree of satisfaction in clinical practice depends on a higher degree of self-directed learning. Therefore, nursing faculty should plan intervention to improve satisfaction level of clinical practice by fostering self-directed learning.

피어슨 곡선족에서 온 표본분포들에 관한 소고

  • 구자흥;유동선
    • Journal for History of Mathematics
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    • v.13 no.1
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    • pp.1-14
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    • 2000
  • The first part of this thesis discusses the Pearson's Curve Family which gives $\beta$distribution, $\Gamma$-distribution, $X^2$-distribution and t-distribution. The second part of this thesis gives some brief process of calculations for normal distribution density and t-distribution density by the 7-th type Curve of Pearson's Curve Family. Finally, a conclusion arrives that Student(Gosset) could not find out his famous 'Student's t-distribution' without his attending of 'Pearson's Differential Equation' class taught by Pearson himself when he was a senior student. However, if he had got a professorship at the Pearson Statistics Laboratory, the University of London, then he could not have found 'Student's t-distribution' for small sampling technique of modern statistics.

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The Relation between the Value Orientations of family, the Psychological Process of Family and Clothing Atitudes (의복에 대한 태도와 가정환경변인과의 관계연구 -부산.경남지역의 남.녀 대학생을 중심으로-)

  • 이경희
    • Journal of the Korean Home Economics Association
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    • v.26 no.3
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    • pp.33-42
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    • 1988
  • The study was to investigate the relationship between clothing variables (Conformity, Modesty, Importance) and environmental variables of Family (the Value Orientations of Family, the Psychological Process of Family), according to sex and region. the subjects were university students in Kyoung nam and Pusan (Male; 397-Pusan 183 and Kyoung nam 214, Female; 401-Pusan 224 and Kyoung Nam 177). Survey method was questionnaires. The data was analyzed with frequency, Pearson's Parson's Correlation, T-test, Multiple Regression using the SPSS. The results were as follows; 1. There was significant difference between clothing Variables in Young nam, but partially significant difference in Pusan. 2. There was partially significant difference between clothing Variables and Environmental Variables of family in each male & female Kyoung nam & Pusan). 3. In the T-test, between clothing Variables and Environmental Variables of family, difference between male and female was shown that female student was higher than male student all of Clothing Variables and male student was higher than female student t in the case of Environmental Variables of family, In the difference between Pusan and Kyoung Nam, male student was shown significant difference in the case of Conformity, materialism and love-Rejection, female student in the case of Modesty, Importance, materialism and Social rising. 4. In the multiple Regression analysis between clothing variables and Environmental Variables of family, clothing voriables partially were effected on the Environmental Variables of family in the cases of male and female in Pusan & Kyoung Nam.

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Edgeworth and Cornish-Fisher Expansion for the Non-normal t

  • Hwang, Hark
    • Journal of the Korean Statistical Society
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    • v.7 no.1
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    • pp.3-10
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    • 1978
  • Let $X_i,...,X_n$ be a random sample from a distribution with cumulants $K_1, K_2,...$. The statistic $t = \frac{\sqrt{x}(\bar{X}-K_1)}{S}$ has the well-known 'student' distribution with $\nu = n-1$ degrees of freedom if the $X_i$ are normally distributed (i.e., $K_i = 0$ for $i \geq 3$). An Edgeworth series expansion for the distribution of t when the $X_i$ are not normally distributed is obtained. The form of this expansion is Prob $(t

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Cosmetology Major The impact of college student satisfaction on the cosmetology profession (헤어미용 전공 대학생의 전공만족도가 미용전문직관에 미치는 영향)

  • Moon, So-Hee;Kong, Cha-Sook
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.6
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    • pp.1667-1677
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    • 2021
  • In this study, we tried to investigate the relationship between the cosmetology major student's major satisfaction and the professionals by analyzing the effect of the cosmetology major student's major satisfaction on the beauty professional hall. Research Results It was found that there is a correlation (p <0.001) between the degree of satisfaction of college students in the hair beauty department and the beauty professionals (p <0.001), and the satisfaction of the department is "specialty" t = 4.625 (p =). .000),'Occupational recognition' t = 3.152 (p = .002), major value is'specialty' t = 2.330 (p = .021),'professional activity' t = 2.438 (p = .015), 'Occupation recognition' t = 4.843 (p = .000), university student activity adaptation is a subordinate factor of the cosmetology profession, "professional activity" t = 2.746 (p = .006), "occupation recognition" t = 4.303 ( Appearing as p = .000), it was found that the degree of satisfaction of college students in the hair beauty department has a significant effect on beauty professionals. For cosmetology college students, major satisfaction not only leads to satisfaction with the university and department, but also to self-satisfaction and cosmetology job confidence, allowing them to adapt to social life with a positive impact, and cosmetologists are hair With the values and attitude toward the beauty profession, you will be able to become a professional officer when you are a university student majoring in cosmetology. Through the research results, the formation of a positive professional hall for college students majoring in hair beauty and the satisfaction of the major will be enhanced, and the self-development of students, as well as professors and educational relations, will be established so that beauty professionals can be established through correct theory and practical education. Education and continued guidance on the professional ethics and values of the person is considered necessary.

The Effect of Multi-faceted Learning by Application Game-based Student Response System in Nursing Education : Focusing on Kahoot! (간호교육에서 게임기반 학생응답시스템을 적용한 다각적인 학습효과 : Kahoot!을 중심으로)

  • Kim, Yu-Jeong
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.4
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    • pp.255-265
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    • 2021
  • The purpose of this study was to examine the effects of Kahoot!(Game-based Student Response System) on nursing education. This study used an one group Pretest-posttest design. Participants were 179 nursing students from one D university located in Gwangju, Korea. The Kahoot!(Game-based Student Response System) was provided for 6 times. Data were collected between August 26 and October 25, 2019. The collected data was analyzed by descriptive statistics, paired t-test, pearson's correlation coefficient and stepwise multiple regression using IBM SPSS 21.0 program. The results showed that learning engagement(t=-6.257, p=.000) was significantly higher than levels before Kahoot!(Game-based Student Response System), critical thinking disposition(t=-2.163, p=.032) was significantly higher than levels before Kahoot!(Game-based Student Response System), problem solving ability(t=-3.032, p=.003) was significantly higher than levels before Kahoot!(Game-based Student Response System). Significant relationships were found among learning engagement(r=.375, p=.000), critical thinking disposition(r=.286, p=.000), problem solving ability(r=.291, p=.000) and learning satisfaction. The results of stepwise multiple regression indicates that learning engagement(β=.307, p=.000), problem solving ability(β=.158, p=.041) predicts 15.2% in learning satisfaction(F=16.905, p=.000). In conclusion, Kahoot!(Game-based Student Response System) is effective in improving learning engagement and problem solving ability to nursing education.

Elementary School Student Teachers' Perceptions of Sustainable Development and Education for Sustainable Development (지속가능발전과 지속가능발전교육에 대한 초등 예비 교사들의 인식)

  • Ju, Hyung-Son;Lee, Sun-Kyung
    • Hwankyungkyoyuk
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    • v.24 no.1
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    • pp.102-113
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    • 2011
  • The role of teachers has been explicitly emphasized to implement the vision of sustainable development(SD). Also, it is very important to understand the way student teachers understand SD and how they interpret their own professional task in terms of SD, usually referred to as education for sustainable development(ESD). This study investigated student teachers' perceptions of SD and ESD using group interview. Key findings include, first, that they think SD as development which does not exceed the limits of natural environment, and as wise management of resources/protection of environment for future generations. They also think SD as good thing though they don't understand the contested nature of SD. Second they think ESD as education about SD, but some student teachers say they can't explain ESD. Many student teachers prefer field trip to local examples for both elementary school students and themselves. Also they will teach only what the textbook says about SD and ESD during their school placement and as teachers. So it will be the beginning of ESD in school to include SD in the curriculum for students and student teachers. It is suggested to study student teachers' perception of SD focussing on how they think the relationship between protection of environment and economic growth.

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