• 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 1^st of January 2012 to 20^th 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).

• Journal of the Korean Society of Physical Medicine
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• v.14 no.3
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• pp.21-27
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• 2019

PURPOSE: This study examined the changes in the kinematic variables during walking on a downhill ramp according to the shoe heel height. METHODS: The subjects were 10 adult women with no history of musculoskeletal disorders who agreed to participate in the study. Data were collected using a motion analysis system (VICON) consisting of six infrared cameras. The slope was 120 cm in width, 200 cm in length, and 15 in inclination. To confirm the change in gait parameters (stride length, gait speed) and lower extremity joint angle according to the heel heights of the shoes, flat, 5 cm, and 10 cm heel shoes were prepared and walked alternately. RESULTS: As a result, both the stride length and walking speed showed significant differences according to the heel height between flat and 10 cm (p<.05). In the sagittal plane, there was no significant difference in the hip joint and knee joint, but a significant difference was observed in all events in the ankle joint on all heel heights (p<.05). In particular, the heel strike and mid stance events showed significant differences among all height conditions (p<.05). No significant difference was observed in any of the joint angle changes in the frontal plane (p>.05). CONCLUSION: As the shoe heel height increased, the instability increased and efforts to secure the stability were made, leading to a shortened stride length, walking speed, and angle of the ankle joint.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.327-340
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• 2003

The purpose of this study was to investigate the height of jump, angle of the ankle and knee, the angular velocity of the ankle and knee between two types of ballet shoes during a jump in the 1st position. The subjects were 5 female ballet majors of university in Busan the majors who have been dancing ballet for six years on the average. The conclusions are as follows: 1. The height of jump had no significant difference between two types of ballet shoes, and then the average of the height of jump with point shoes group ($20.24{\pm}4.62\;cm$) was a little higher than ballet shoes group ($17.50{\pm}4.05\;cm$). 2. The angle of the ankle had no significant difference for all events between two types of ballet shoes. The minimum angle of ankle joint was represented to $54.36_{\circ}$ at the E1 of the left ankle angle of the ballet shoes and the maximum value was showed $155.43_{\circ}$ at the E3 of the right ankle angle of the point shoes. 3. The angle of the knee had no significant difference for all events between two types of ballet shoes. The minimum angle of knee joint was represented to $99.54_{\circ}$ at the E1 of the left knee angle of the ballet shoes and the maximum value was showed $174.25_{\circ}$ at the E3 of the right knee angle of the point shoes. 4. The ankle velocity of the ankle had no significant difference for all events between two types of ballet shoes. The minimum angular velocity of the ankle was represented to 4.35 deg/s at the maximum height(E3) of the point shoes and the maximum value was showed 597.81 deg/s at the take-off(E2) of the right ankle angle of the point shoes. 5. The angular velocity of the knee had significant difference between two types of ballet shoes at the event 1(p<.05). The minimum angular velocity of the hee was represented to -1.68 deg/s at the maximum height(E3) of the point shoes and the maximum value was showed 360.25 deg/s at the take-off(E2) of the left knee angle of the ballet shoes. The other events had no significant difference between two types of ballet shoes.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.2
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• pp.193-197
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• 2014

To investigate the degree of individuals' likability of insects, a survey was conducted with students and adults living in Korea. Overall, for insect-related questions, positive responses were higher than negative ones. Among the positive responses, the personal rearing of insects scored lower than others. The unconditional dislike of insects scored highest in the negative responses. A significant differences and correlations were found between males and females, students and adults, people experienced in insect-related events and those who were not. In particular, previous experience in insect-related events significantly influenced insect likability. Subjects preferred coleopteran and lepidopteran insects to others. However, this preference of insects differed by gender: Male participants preferred coleopteran insects to lepidopteran insects, while female participants preferred lepidopteran insects to coleopteran ones. No significant differences in the preference of insects were found by participants' job, residence, or experience in insect-related events. These findings suggest that gender is the most important factor to consider in selecting insects to be used as therapeutic tools in mental health care.

• Wind and Structures
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• v.38 no.3
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• pp.171-191
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• 2024

Wind Driven Rain (WDR) poses a significant threat to the building environment, especially in hurricane prone regions by causing interior and content damage during tropical storms and hurricanes. The damage due to rain intrusion depends on the total amount of water that enters the building; however, owing to the use of inadequate empirical methods, the amount of water intrusion is difficult to estimate accurately. Hence, the need to achieve full-scale testing capable of realistically simulating rain intrusion is widely recognized. This paper presents results of a full-scale experimental simulation at the NHERI Wall of Wind Experimental Facility (WOW EF) aimed at obtaining realistic rain characteristics as experienced by structures during tropical storms and hurricanes. A full-scale simulation of rain in strong winds would allow testing WDR intrusion through typical building components. A study of rain intrusion through a sliding glass door is presented, which accounted for the effects of multiple wind directions, test durations and wind speeds; configurations with and without shuttering systems were also considered. The study showed that significant levels of water intrusion can occur during conditions well below current design levels. The knowledge gained through this work may enhance risk modeling pertaining to loss estimates due to WDR intrusion in buildings, and it may help quantify the potential reduction of losses due to the additional protection from shuttering systems on sliding glass doors during winds.

• Child Health Nursing Research
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• v.30 no.3
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• pp.176-186
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• 2024

Purpose: With the recent increase in interest in patient safety, prevention of falls in hospitalized children has become important. This study aimed to identify the incidence rate of falls among hospitalized children and explore fall-related characteristics. Methods: This retrospective descriptive study analyzed the medical information of 18,119 patients aged <18 years admitted to a general hospital in South Korea from electronic medical records and fall event reports between January 1, 2018, and September 30, 2023. The study variables included the general and clinical characteristics of the fall group and fall-related characteristics of the fall events. This study employed descriptive statistics and a chi-square test using IBM SPSS version 26.0. Results: Among the patients, 82 fall events were identified. Therefore, the fall incidence rate was 4.5 falls per 1,000 patients. Furthermore, a statistically significant difference was found concerning the type of injury sustained between children >1 year old and those <1 year old, and most cases had no damage or bruises. More cases were found in which falls occurred two days after hospitalization in winter and summer than on the day or the day after hospitalization, which was a statistically significant difference. In addition, fall prevalence was higher between 8 am and 4 pm, and when no caregiver was present. Conclusion: Based on the results of this study, education and interventions to prevent fall events in infants and toddlers should persist throughout hospitalization, and it is necessary to guide continuous management and observation of the caregivers.

• Journal of the Korean Home Economics Association
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• v.36 no.8
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• pp.1-12
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• 1998

The purpose of this study was to investigate the relationship between children's attributional style and their self-perceived competence. The subjects of this study were 301 third and sixth grades. For data analysis, two-way ANOVA, Pearson's correlation coefficients, and multiple regression were used. Results indicated that there was significant correlation between children's attributional style and their self-perceived competence. Children who attributed good events to intemal, stable, or global causes and bad events to extemal, unstable, or specific causes perceived themselves more competent.

• Journal of People, Plants, and Environment
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• v.22 no.5
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• pp.435-444
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• 2019

This study is based on the premise that a garden space is a place that not only requires physical labor but also encourages conversation in the gardening group. We suggest the use of urban gardens as a place to revitalize local communities by promoting people to participate in various event programs. Through the theoretical study, we set the requirements that can be applied to "urban garden events". We developed measurement items and scales to be used as variables of each construction concept. Our survey was conducted on adults aged 19 and above who visited the 8th Korean Urban Agriculture Expo. Out of total 310 copies of the distributed questionnaire, only 298 effective samples were used in the empirical analysis. We can assume that people want to revitalize local communities based on the fact that 71 (23.8%) participants said they thought the purpose of the event is to achieve unity among residents. Throughout analysis, 15 of the necessary items were confirmed and classified into two factors: image of event (Factor 1) and evaluation item (Factor 2). As a result of verifying the relationship between educational level for Factor 1, age was significant in five items and education level was significant in six items. For Factor 2, four items were effective in relation to education level, while significant results were not found in relation to age. These results are expected to be significant if the intellectual curiosity of the residents is satisfied and the demand base of the urban garden events according to the characteristics of city people is expanded. Based on this study, it is necessary to conduct research on the use of urban gardens as an event with social functions as well as various programs that can be carried out in gardens to build and revitalize the community.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.63-71
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• 2020

In this paper, we propose the new time-varying coefficient GARCH-in-Mean model. The benefit of our model is to allow the risk-return parameter in the mean equation to vary over time. At the end of 2019 to the beginning of 2020, the world witnessed two shocking events: COVID-19 pandemic and 2020 oil price war. So, we decide to use the daily data from December 2, 2019 to May 29, 2020, which cover these two major events. The purpose of this study is to find the dynamic movement between risk and return in four major oil markets: Brent, West Texas Intermediate, Dubai, and Singapore Exchange, during COVID-19 pandemic and 2020 oil price war. For the European oil market, our model found a significant and positive risk-return relationship in Brent during March 26-April 21, 2020. For the North America oil market, our model found a significant positive risk return relationship in West Texas Intermediate (WTI) during March 12-May 8, 2020. For the Middle East oil market, we found a significant and positive risk-return relationship in Dubai during March 12-April 14, 2020. Lastly, for the South East Asia oil market, we found a significant positive risk return relationship in Singapore Exchange (SGX) from March 9-May 29, 2020.

• Communications for Statistical Applications and Methods
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• v.19 no.4
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• pp.537-546
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• 2012

In this paper, for analyzing binary data, Poisson regression with offset and logistic regression are compared with respect to the power via simulations. Poisson distribution can be used as an approximation of binomial distribution when n is large and p is small; however, we investigate if the same conditions can be held for the power of significant tests between logistic regression and offset poisson regression. The result is that when offset size is large for rare events offset poisson regression has a similar power to logistic regression, but it has an acceptable power even with a moderate prevalence rate. However, with a small offset size (< 10), offset poisson regression should be used with caution for rare events or common events. These results would be good guidelines for users who want to use offset poisson regression models for binary data.