• Title/Summary/Keyword: conditional effect

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Formulating the Landscape Preference Model Using a Mixed Conditional Logit (조건부 로짓함수를 이용한 경관선호 모델: 지리산 국립공원 방문자를 대상으로)

  • Lee, Deokjae
    • Journal of Korean Society of Forest Science
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    • v.95 no.6
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    • pp.768-777
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    • 2006
  • The purpose of this study lies in formulating the landscape preference model using a conditional logit that involves the effect of visual elements as well as landscape itself on landscape preferences. To measure landscape preferences, a photo-questionnaire composed of paired photographs of the Cairngorms National Park of Scotland and the Jirisan National Park of Korea was distributed to visitors to the Jirisan National Park of Korea. Visual elements of landscape quantitatively measured by photogrammetry were reduced to orthogonal principal components that were subsequently used as explanatory variables in a conditional logit. As a result, the mixed conditional logit including the effect of landscape itself satisfied the Independence of Irrelevant Alternatives (IIA) property and showed reliable goodness of fit (${\rho}^2=0.25$). It was concluded that the mixed conditional logit including the effect of landscape itself was appropriate for landscape preference model rather than usual conditional logit excluding the effect.

Young Chilldren's Causal Reasoning on Psychology and Biology : Focusing on the Interaction between Domain-specificty and Domain-generality (심리와 생물 영역에서의 유아의 인과추론 : 영역특정성과 영역일반성의 상호작용)

  • Kim, Ji-Hyun
    • Journal of Families and Better Life
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    • v.26 no.5
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    • pp.333-354
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    • 2008
  • This study aimed to investigate the role of domain-specific causal mechanism information and domain-general conditional probability in young children's causal reasoning on psychology and biology. Participants were 121 3-year-olds and 121 4-year-olds recruited from seven childcare centers in Seoul, Kyonggi Province, and Busan. After participants watched moving pictures on psychological and biological phenomena, they were asked to choose appropriate cause and justify their choices. Results of this study were as follows: First, young children made different inferences according to domain-specific causal mechanisms. Second, the developmental level of causal mechanisms has a gap between psychology and biology, and biological knowledge was proved to be separate from psychological knowledge during the preschool period. Third, young children's causal reasoning was different depending on the interaction effect of domain-specific mechanisms and domain-general conditional probability: children could make more inferences based on domain-specific causal mechanisms if conditional probability between domain-appropriate cause and effect was evident. To conclude, it can be inferred that the role of domain-specific causal mechanisms and domain-general conditional probability is not competitive but complementary in young children's causal reasoning.

The Role of Domain-specific Causal Mechanism and Domain-general Conditional Probability in Young Children's Causal Reasoning on Physics and Psychology (영역특정론과 영역일반론에 따른 유아의 인과추론 - 물리, 심리 영역을 중심으로 -)

  • Kim, Jihyun;Yi, Soon Hyung
    • Korean Journal of Child Studies
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    • v.29 no.5
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    • pp.243-269
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    • 2008
  • The role of domain-specific causal mechanism information and domain-general conditional probability in young children's causal reasoning on physics and psychology was investigated with the participation of 121 3-year-olds and 121 4-year-olds recruited from seven child care centers in Seoul, Kyonggi Province, and Busan. Children watched moving pictures on physical and psychological phenomena, and were asked to choose an appropriate cause and justify their choice. Results showed that young children's causal reasoning differed depending on domain-specific mechanism. In addition, their causal reasoning on physics and psychology differed by the developmental level of causal mechanism. The interaction of domain-specific mechanism and domain-general conditional probability influenced children's causal reasoning : evident conditional probability between domain-appropriate cause and effect helped children make more inferences based on domain-specific causal mechanism.

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Lunar Effect on Stock Returns and Volatility: An Empirical Study of Islamic Countries

  • MOHAMED YOUSOP, Nur Liyana;WAN ZAKARIA, Wan Mohd Farid;AHMAD, Zuraidah;RAMDHAN, Nur'Asyiqin;MOHD HASAN ABDULLAH, Norhasniza;RUSGIANTO, Sulistya
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.533-542
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    • 2021
  • The main objective of this article is to investigate the existence of the lunar effect during the full moon period (FM period) and the new moon period (NM period) on the selected Islamic stock market returns and volatilities. For this purpose, the Ordinary Least Squares model, Autoregressive Conditional Heteroscedasticity model, Generalised Autoregressive Conditional Heteroscedasticity model and Generalised Autoregressive Conditional Heteroscedasticity-in-Mean model are employed using the mean daily returns data between January 2010 and December 2019. Next, the log-likelihood, Akaike Information Criterion and Schwarz Information Criterion value are analyzed to determine the best models for explaining the returns and volatility of returns. The empirical results have deduced that, during the NM period, excluding Malaysia, the total mean daily returns for all of the selected countries have increased mean daily returns in contrast to the mean daily returns during the FM period. The volatility shocks are intense and conditional volatility is persistent in all countries. Subsequently, the volatility behavior tends to have lower volatility during the FM period and NM period in the Islamic stock market, except Malaysia. This article also concluded that the ARCH (1) model is the preferred model for stock returns whereas GARCH-M (1, 1) is preferred for the volatility of returns.

Effect of Dimension in Optimal Dimension Reduction Estimation for Conditional Mean Multivariate Regression (다변량회귀 조건부 평균모형에 대한 최적 차원축소 방법에서 차원수가 결과에 미치는 영향)

  • Seo, Eun-Kyoung;Park, Chong-Sun
    • Communications for Statistical Applications and Methods
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    • v.19 no.1
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    • pp.107-115
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    • 2012
  • Yoo and Cook (2007) developed an optimal sufficient dimension reduction methodology for the conditional mean in multivariate regression and it is known that their method is asymptotically optimal and its test statistic has a chi-squared distribution asymptotically under the null hypothesis. To check the effect of dimension used in estimation on regression coefficients and the explanatory power of the conditional mean model in multivariate regression, we applied their method to several simulated data sets with various dimensions. A small simulation study showed that it is quite helpful to search for an appropriate dimension for a given data set if we use the asymptotic test for the dimension as well as results from the estimation with several dimensions simultaneously.

Boosting green cars retail in Malaysia: The influence of conditional value on consumers behaviour

  • ALGANAD, Amr Mohammed Nasser;ISA, Normalisa Md;FAUZI, Waida Irani Mohd
    • Journal of Distribution Science
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    • v.19 no.7
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    • pp.87-100
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    • 2021
  • Purpose: This paper examined the role of conditional value in the green automotive industry. The relationships of conditional value's four factors, consumers' attitudes and consumers' intention to purchase green cars were investigated. The conditional value was extended by examining the effect of fuel prices. Research design, data, and methodology: This study is quantitatively designed. All variables were measured using a 7-point Likert-scale; 425 questionnaires were collected from the respondents in Malaysia. SmartPLS was utilized to examine the proposed nine hypotheses. Result: The results demonstrate a positive relationship between attitude and intention toward green cars. Additionally, the results of the relationships were as follows: fuel prices was the most significant predictor of Malaysian consumers' attitudes and consumers' intention to purchase green cars, followed by environmental consequences and government policy. However, retail sales promotions did not show a significant effect on both consumers' attitudes and intentions. Conclusion: The study's findings suggest that the Malaysian government should implement an integrated package that includes a fuel pricing policy that restricts the purchase of non-green cars, as well as a set of financial incentives for purchasing green cars. Moreover, it is valuable to conduct public awareness campaigns about the negative consequences of current consumption patterns.

The Relationships among Learning Agility, Unlearning, and Learning Flow of University Students: Conditional Direct and Indirect Effects by Gender (대학생의 학습민첩성과 폐기학습, 학습몰입의 관계: 성별에 따른 조건부 효과)

  • Wee, Youngeun;Kim, Woocheol;Lee, Jiyoung
    • Journal of Practical Engineering Education
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    • v.14 no.2
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    • pp.313-325
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    • 2022
  • This study aims to identify the conditional direct and indirect effects by Gender in the relationship between Learning Agility, Unlearning and Learning Flow for university students. Based on the data collected from 265 university students the conditional effectiveness of the research model was analyzed using Process v3.4 for SPSS. As a result, first, the Learning Agility of university students had a statistically significant effect Unlearning and Learning Flow. Second, Learning Agility had a statistically significant direct effect on Learning Flow by gender but, the moderated effect of Learning Flow had a significant negative effect. Third, the moderated mediating effect of Unlearning by gender was found to be significant in the relationship between Learning Agility and Learning Flow of university students. Based on these results, implications of education at university were presented.

A Predictive Model for Sensory Difference Tests Accounting for Sequence Effects

  • Lee, Hye-Seong
    • Food Science and Biotechnology
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    • v.17 no.5
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    • pp.1052-1059
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    • 2008
  • Sequential Sensitivity Analysis (SSA) and conditional stimulus model have been developed to describe sequence effects in difference tests and proposed to generate prediction of differences in sensitivity between various test protocols and to assist the appropriate selection of difference test. Yet, such models did not furnish a complete explanation of the relative sensitivity in 4 different versions of 3-alternative forced choice (AFC) tests where various interstimulus rinses were introduced. In the present study, the vector of the contrasts between various conditional stimuli were measured using same-different and 2-AFC and a new 16-distribution conditional stimulus model was developed by refining Lee and O'Mahony's contrast model. This new model gave superior predictions than previous models.

Comparison of Control Methods for Estimation Bias in Unmatched Analysis of Matched Data (짝을 이룬 자료분석시 야기되는 Estimation Bias의 Control Methods)

  • Yoo, Keun-Young
    • Journal of Preventive Medicine and Public Health
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    • v.23 no.3 s.31
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    • pp.247-254
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    • 1990
  • 짝짓기 방법은 교란변수를 통제하기 가장 좋은 방법으로 알려져 있으나, 모수추정시 그 계산방법이 복잡하고, 포함된 모든 정보를 이용할 수 없다는 단점을 갖고 있다. 그럼에도 불구하고, conditional 모델을 이용한 matched 분석법은 짝지은 자료 분석시 가장 좋은 방법으로 인정되고 있다. 그러나 명확한 confounding 현상을 통제할 목적이 아닌 상태에서 짝지워진 자료를 matched 분석법으로 모수추정하는 경우나, 올바로 짝지워진 자료를 분석법의 편이성 때문에 unmatched 분석을 시도하는 경우, 오히려 estimation bias가 야기될 수 있다. 이러한 estimation bias의 통제능력을 몇 가지 분석방법을 이용하여 비교하고자, 1:2로 대응된 한 환자-대조군 자료를 이용하여 Mantel-Haenszel 분석법, 두가지의 unconditional model을 이용한 다변량분석법의 결과를 conditional model을 이용한 matched 분석법의 결과와 비교하였다. 1. Matched 분석법의 대용방법으로 사용된 세 가지 방법들은 모수추정면에서나 가설검정능력면에서 차이를 서로 보이지 않았다. 2. 짝짓기에 사용된 변수가 분석자료내에서 confounder나 effect modifier로 작용되지 않았음이 명백한 경우에는 이들 세 가지 통제 방법과 matched 분석법간에 차이가 없었다. 3. 짝짓기에 사용된 변수가 분석자료내에서 effect modifier로 작용하지는 않았으나, Confounder로 작용한 것으로 추정되는 경우, unmatched 분석법으로 인해 야기된 estimation bias의 통제능력이 이들 세 가지 대용방안 모두에서 인정되었다. 4. 짝짓기에 사용된 변수가 분석자료내에서 effect modifier로 작용하고 있음을 직접 확인할 수 있는 경우에는, overmatching에 의한 estimation bias를 의심할 수 있었으며, 이들 세 가지 통제방법은 오히려 unmatched 분석 방법에 가까운 모수를 추정하였다.

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The Impact of COVID-19, Day-of-the-Week Effect, and Information Flows on Bitcoin's Return and Volatility

  • LIU, Ying Sing;LEE, Liza
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.45-53
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    • 2020
  • Past literatures have not studied the impact of real-world events or information on the return and volatility of virtual currencies, particularly on the COVID-19 event, day-of-the-week effect, daily high-low price spreads and information flow rate. The study uses the ARMA-GARCH model to capture Bitcoin's return and conditional volatility, and explores the impact of information flow rate on conditional volatility in the Bitcoin market based on the Mixture Distribution Hypothesis (Clark, 1973). There were 3,064 samples collected during the period from 1st of January 2012 to 20th April, 2020. Empirical results show that in the Bitcoin market, a daily high-low price spread has a significant inverse relationship for daily return, and information flow rate has a significant positive relationship for condition volatility. The study supports a significant negative relationship between information asymmetry and daily return, and there is a significant positive relationship between daily trading volume and condition volatility. When Bitcoin trades on Saturday & Sunday, there is a significant reverse relationship for conditional volatility and there exists a day-of-the-week volatility effect. Under the impact of COVID-19 event, Bitcoin's condition volatility has increased significantly, indicating the risk of price changes. Finally, the Bitcoin's return has no impact on COVID-19 events and holidays (Saturday & Sunday).