• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.124-129
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• 2021

As the 4th industrial era is in full swing, the public's interest in related technologies such as artificial intelligence, big data, and block chain is increasing. As artificial intelligence technology is used in various industrial fields, the need for research methods incorporating artificial intelligence technology in related fields is also increasing. Evidence collection among digital forensic investigation techniques is a very important procedure in the investigation process that needs to prove a specific person's suspicions. However, there may be cases in which evidence is damaged due to intentional damage to evidence or other physical reasons, and there is a limit to the collection of evidence in this situation. Therefore, this paper we intends to propose an artificial intelligence-based evidence collection system that analyzes numerous image files reported by citizens in real time to visually check the location, user information, and shooting time of the image files. When this system is applied, it is expected that the evidence expected data collected in real time can be actually used as evidence, and it is also expected that the risk area analysis will be possible through big data analysis.

• Journal of Hydrogen and New Energy
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• v.33 no.2
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• pp.121-129
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• 2022

With the advent of the post-2020 climate regime, the hydrogen industry is growing rapidly around the world. In order to build the hydrogen economy, it is important to identify social issues related to hydrogen and prepare countermeasures for them. Accordingly, this study conducted a semantic network analysis on hydrogen news from NAVER. As a result of the analysis, the number of hydrogen news in 2020 increased by 4.5 times compared to 2016, and as of 2018, the hydrogen issue has shifted from an environmental aspect to an economic aspect. In addition, although the initial government-led hydrogen industry is expanding to the mobility field such as privately-led fuel cell electric vehicles and hydrogen fuel, terms showing concerns about the safety such as explosions are constantly being exposed. Thus, it is necessary not only to expand the hydrogen ecosystem through the participation of private companies, but also to promote hydrogen safety.

• New & Renewable Energy
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• v.19 no.4
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• pp.98-107
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• 2023

A study was conducted to analyze data from 1981 to 2020 for understanding the impact of climate on solar energy generation. A significant increase of 104.6 kWhm^-2 was observed in the annual cumulative solar radiation over this period. Notably, the distribution of solar radiation shifted, with the solar radiation in Busan rising from the seventh place in 1981 to the second place in 2020 in South Korea. This study also examined the correlation between long-term temperature trends and solar radiation. Areas with the highest solar radiation in 2020, such as Busan, Gwangju, Daegu, and Jinju, exhibited strong positive correlations, suggesting that increased solar radiation contributed to higher temperatures. Conversely, regions like Seosan and Mokpo showed lower temperature increases due to factors such as reduced cloud cover. To evaluate the impact on solar energy production, simulations were conducted using climate data from both years. The results revealed that relying solely on historical data for solar energy predictions could lead to overestimations in some areas, including Seosan or Jinju, and underestimations in others such as Busan. Hence, considering long-term climate variability is vital for accurate solar energy forecasting and ensuring the economic feasibility of solar projects.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.35 no.4
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• pp.258-265
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• 2024

Objectives: This study aimed to examine sex differences in the risk factors associated with generalized anxiety disorder (GAD) among Korean adolescents to provide insights for drafting more effective prevention strategies. Methods: Data from 51845 middle and high school students in the 18th Korea Youth Risk Behavior Web-based Survey were analyzed. GAD was assessed using the 7-item Generalized Anxiety Disorder tool, and factors such as grade, academic performance, economic status, living arrangements, smoking, drinking, sexual experience, and physical activity were included. The prevalence of GAD and its association with these factors were compared between male and female students using chi-square tests and logistic regression. Odds ratios were compared statistically to identify sex-specific differences. Results: GAD prevalence was higher among girls (42.1%) than boys (30.1%). Both sexes showed increased GAD risk with lower academic performance, lower economic status, smoking, drinking, and sexual experience. Boys living apart from their families had a higher GAD risk, but this was not significant for girls. Additionally, smoking and drinking were associated with a higher increase in GAD risk in girls than in boys. Conclusion: This study underscores the importance of considering sex differences in the prevention of GAD among adolescents. Tailored sex-specific interventions are crucial for effective prevention and management of GAD in Korean adolescents.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.279-285
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• 2020

In the era of the Fourth Industrial Revolution, there are many sensors around. People and things are connected to these sensors to the internet. Numerous connected sensors produce the latest data in seconds, and these data are stacked with big data of unimaginable size. Because personal information can be contained in any place of data produced, device and system protection are needed. Digital twins are virtual models that accurately reflect the status information of physical assets and systems that utilize them. The characteristic of digital twin is that digital twin itself has temporal and structural identity enough to represent the object of reality. In the virtual environment the reproduced reality, it continuously simulates and it virtuals of the point of time or the future, the replica can be created. Therefore, this study cited factors threatening personal information in the era of the Fourth Industrial Revolution. And proposed using digital twin technology that can simulate in real-time to overcome the risk of personal information hacking.

• Journal of the Korean Geographical Society
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• v.46 no.1
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• pp.36-49
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• 2011

This paper aims to investigate the frequency and intensity variations of Okhotsk high pressure system focused on the Korean Peninsula. Weather chart (00UTC), daily weather data and reanalysis data were used. The first occurrence date of Okhotsk high pressure system tends to be earlier in those years that surrounding land air temperature in April is high. The frequency of Okhotsk high has recently decreased, and its intensity tends to be stronger when the difference between sea surface temperature and surrounding land air temperature is big. The frequency of Okhotsk high in April, May, June and July increases when surrounding land air temperature is high, and its intensity grows when the difference between surrounding land air temperature and sea surface temperature is big. The frequency of Okhotsk high may increase and its intensity may increase when the first occurrence date comes earlier. In June, however, the reverse may apply.

• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.231-240
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• 2016

The purpose of this study is to investigate the relationship among fatigue, personality, learning strategies, and academic achievement of medical students. 146 students from year 1 to year 4 at one medical school participated in this study. Students completed the fatigue, Big Five personality traits(Neuroticism, Extraversion, Openness, Agreeableness, Conscientiousness), learning, strategies. The academic achievement of students measured by GPA. The data were analyzed by t-test and stepwise multiple regression. The student's fatigue differed by grade, and the students of low grade had higher scores than high grade. But personality traits and learning strategies were not significantly different by grade. The factors that affect on academic achievement differ by grade. In low grade, neuroticism, extraversion, and rehearsal affected students' academic achievement. In high grade, conscientiousness and extraversion had an effect on the academic achievement of students. These results could guide the design of medical education improvement, and be useful in developing a supporting program for medical students.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.1
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• pp.1-10
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• 2016

The purpose of this study was to investigate the need to develop foods for the elderly based on their food preferences. A one-to-one survey method was used for data collection, and the survey was conducted on 165 elderly people (male: 47, female: 118) attending senior welfare centers in Seoul. The results of this study show that the preferred cooking method was steaming rather than stir-frying. Vegetables (4.24), fruits (4.22), Kimchi (3.87), fish (3.83), tofu (3.81), rice-cakes (3.65), dairy products/eggs (3.47), meat (3.45), noodles (3.44), seafood (3.44), poultry (3.23), bread/cookies (3.10) showed high preferences in order (p<0.05). The respondent's chewing & swallowing degree were "Not uncomfortable chew" 31.5%, "Hard food, and a big food is a little difficult to intake". 37%, "Hard food, and a big food is difficult to intake" 11.5%, "Small food, and soft foods can intake" 11.5%, and "It is difficult to intake solid food" 1.2%. Foods that were difficult to chew were meat 28.3%, seafood 15.2%, vegetables 15.2%, nuts 14.1%, fruits 12.0%, Kimchi 8.7%, and other 6.5%. For respondents, the most important factors affecting choice of elderly foods were flavor (48.5%), hygiene (43.0%), and nutrition (36.4%). The elderly wanted "Ready to eat (RTE)" 53.9%, "Ready to heat (RTH)" 15.8%, "Ready to cook (RTC)" 21.2%, and 'Fresh cut product" 9.1%.

• Plant Resources
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• v.8 no.3
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• pp.235-243
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• 2005

The purpose of this research is to establish basic database on Cornus kousa by way of investigation, analysis and comparison of characteristics of leaf and flower, then fostering good cultivar on each morphological characteristics - leaf length, leaf width, petiole length, left lateral vein, right lateral vein. Leaf length and leaf width in Mt. Jiri shows big tendency which is 83.5 mm, 52.4 mm each in comparison with the whole mean of 72.5 mm, 41.2 mm, whereas populations of Suwon and Mt. Halla has leaf length of 66.0 mm, 65.7 mm - 9.8%, 10.4% lower value in comparison with seven mean population; leaf width is 38.4 mm, 35.3 mm - 7.3%, 16.7% lower than whole mean and shows lowest tendency among seven selected populations. Long width of flower and short width of flower in Boeun shows big tendency which is 99.9mm, 96.5 mm each in comparison with the whole mean of 76.0 mm, 73.6 mm, whereas populations of Mt. Halla has 50.1 mm, 48.2 mm which shows lowest tendency. On petal length, petal width and length of flower petiole, Boeun populations have bigger and Mt. Halla shows little tendency. The measurement result of flower colors on each population by using Spectrum Color Mater shows followings: populations of Mt. Duckyoo and Mt. Halla shows lower lightness than any other populations, but wholly shows higher lightness which is refers brightness in seven selected populations. Thus it shows peculiarities of white flower color.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.8B
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• pp.1012-1020
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• 2011

In this paper a design of $\pi$/4-DQPSK baseband receiver for the exchange of digital data and e-mail between shore and ship stations and/or among ship stations in the maritime mobile service VHF channels is described. Due to the permitted relatively big frequency instability of local oscillators at the transmitter and the receiver of maritime communication system, the designed baseband receiver should have the capabilities of correct estimation and compensation of the synchronization parameters, such as symbol timing and frequency offset, from the received signal which might include relatively big frequency error. Simulated BER results show that the designed baseband receiver works less than 0.5dB loss under AWGN channel when the normalized frequency offset of the received signal is more then 20%.