• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.7
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• pp.70-82
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• 1993

In this paper, employing the 3-dimensional discrete cosine transform (DCT) for the utilization of the temporal correlation, an adaptive motion sequence coding technique is proposed. The energy distribution in a 3-D DCT block, due to the nonstationary nature of the image data, varies along the veritical, horizontal and temporal directions. Thus, aiming an adaptive system to local variations, adaptive procedures, such as the 3-D classification, the classified linear scanning technique and the VLC table selection scheme, have been implemented in our approach. Also, a hybrid structure which adaptively combines inter-frame coding is presented, and it is found that the adaptive hybrid frame coding technique shows a significant performance gain for a moving sequence which contains a relatively small moving area. Through an intensive computer simulation, it is demonstrated that, the performance of the proposed 3-D transform coding technique shows a close relation with the temporal variation of the sequence to be code. And the proposed technique has the advantages of skipping the computationally complex motion compensation procedure and improving the performance over the 2-D motion compensated transform coding technique for rates in the range of 0.5 ~ 1.0 bpp.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3164-3170
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• 2000

The use of the A' for the path search of the agent in the game map give the overhead of computing time in real time game processing. The other heuristic search algorithms do not guarantee the optical path. The route table of which the row is defined by current position, goal position, visiting position is presented in this paper. This route table is made in the game development phase and tilized in game playing. The visiting position which is contatined in the optimal path to the goal position from the current position can guarantee the optical path, and this mothod has no overhead on computing time. But the memory space is requred too much. This problem can also be solved using the data compression by skipping the duplicated route table.

• Journal of the Korean Society of Food Culture
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• v.27 no.1
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• pp.38-48
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• 2012

This study was conducted to examine dietary behaviors according to residence status and ethnicity of university students in Yanbian, China. For the subjects, 334 university students (Male=141, Female=193) answered a questionnaire about perception of weight control, dietary patterns, health habits, residence status, and ethnicity. Perception of weight, meal frequency, favorite kind of food, meal finishing time, skipping breakfast, type of breakfast, snack frequency, late-night snack frequency, exercise frequency, regular life, and sleeping time were all significantly associated with residence status. Motivation of weight control, meal frequency, regularity of meal time, meal volume, favorite kind of food, exercise time, and regular life were all significantly associated with ethnicity. University students who lived with their parents perceived their weight more properly, exhibited a more positive dietary pattern, and lived a more regular life than those students who lived in a dormitory with their friends. Chinese students exhibited a more regular dietary pattern and lived a more regular life than the Korean-Chinese students. As a result, both environmental and inherent factors are related with the dietary behaviors of university students in Yanbian, China. These data could be used to help university students in Yanbian, China attain a healthy diet.

• Journal of Korean society of Dental Hygiene
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• v.22 no.5
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• pp.355-363
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• 2022

Objectives: This study aimed to assess the relationship between oral symptoms and changes in daily life after coronavirus disease (COVID-19) in middle and high school students. Methods: Data were obtained from the 17th Korea Youth Risk Behavior Survey (2021). The subjects comprised 53,868 people who responded to survey questions related to this study. Multiple logistic regression analysis with complex samples was performed to identify the correlation between daily life changes and oral symptoms. Results: The analysis showed that compared to the group without changes in daily life after COVID-19, changes in daily life, such as skipping breakfast, drinking, and smoking, either decreased or increased. Furthermore, increase in depression and decreased physical activity and family economic status were related to oral symptoms. Conclusions: It is necessary to develop oral health programs for adolescents suitable for changing situations after COVID-19.

• The Korean Journal of Food & Health Convergence
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• v.8 no.1
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• pp.1-7
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• 2022

This study classified subjects aged 30 to 64 into normal group, impaired fasting glucose group, and diabetes mellitus patient group based on data from the 6th period of the National Health and Nutrition Examination Survey (2013-2015). Skipping breakfast, lack of physical activity, inadequate sleep time, inadequate weight, excessive drinking, and current smoking are classified as a low health risk group when three or less items are present, and a high health risk group when three or more items are included. By classification, each item included in the physical measurement and biochemical analysis factors and health risk behavior factors was comparatively analyzed. As a result, in the normal group, impaired fasting glucose group, and diabetes group, the average age was higher in the group with high health risk factors than the group with low risk factors, and the male ratio was higher. Body mass index, waist circumference, blood pressure, triglyceride showed a significantly higher result. In the normal group, the fasting blood glucose level and total cholesterol level were also higher in group 2. Therefore, it is thought that it is necessary to control health risk behaviors through lifestyle changes in the normal group, fasting glucose disorder group, and diabetes group.

• Journal of the Korean Home Economics Association
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• v.45 no.10
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• pp.1-11
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• 2007

This study was performed to identify the nutritional status and eating behaviors of underweight adolescent females aged 15 to 19 years. The subjects were selected using data from 2001 NHANS of Korea, and included 28 underweight and 160 normal-weight subjects. We found that the underweight group had significantly lower weight (9.8 kg), waist (6.9 cm), and hip circumference (7.2 cm) values than the normal-weight group; however height and waist-hip ratio were not different. Serum indices were within normal ranges and showed no differences between the two groups. The energy and nutrient intakes of most of the subjects were considered poor. For intake levels, the proportion of subjects below the EAR, NAR and INQ of each nutrient were also not significantly different between the groups. There were no differences in frequency for skipping meals, snacking, and eating-out between the groups. When comparing food frequency data for 62 food items, the underweight group consumed significantly more often of eggs, dried anchovies, mackerel, shellfish, and mushrooms than the normal-weight group. The former also had significantly less excercise/walking, more diet-control, and more rest/sleep than the latter. Subjects in both of two groups perceived their body images as over weight, so they practiced diet-control to reduce body weight, which is considered harmful as a healthy weight. In conclusion, the underweight group showed no differences in items of biochemical indices, nutrient intakes, and many dietary behaviors, but subjects revealed significantly higher food intake frequencies for several protein foods, as well as less excercise/walking, and more rest/sleep than the normal-weight group.

• The Korean Journal of Food And Nutrition
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• v.27 no.4
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• pp.660-672
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• 2014

The purpose of this study was to evaluate dietary habit and nutritional status by household income in female adults, using data from the $4^{th}$ Korea National Health and Nutrition Examination Survey (2007~2009). Subjects were 8,356 women over the age of 20 years. The subjects were classified into 4 groups by household income level. Dietary data from 24 hr recall methods were used to analyze nutritional status. The obesity rate of the low income group was significantly higher than the rates of other income groups. Additionally, the nutritional status of the low income group was worse than those of other groups. The percentage of carbohydrate in total energy intake was higher and food security status was lower in the low income group than in other groups. Awareness and adherence to dietary guidelines were also lower in the low income group. Adherence to a dietary guideline of 'avoiding salty foods and trying to eat foods with bland taste' and 'eating a variety of foods from each food group' were lower than those of other groups. However, the frequency of skipping breakfast among the low income group was lower than that of others. Therefore, this study suggested that low income women should decrease the percentage of carbohydrate in total energy intake and adhere to dietary guidelines, especially those of avoiding salty foods and eating a variety of food groups, in order to improve their nutritional status.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.2
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• pp.246-260
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• 2015

The purpose of this study was to evaluate the prevalence of obesity, dietary habits, and nutritional status by age among low-income women, using data from the fourth Korea National Health and Nutrition Examination Survey (2007~2009). Subjects were 8,356 women aged 20 and over. The subjects were classified into four groups by age. Dietary data from 24-hr recall methods were used to analyze nutritional status. The prevalence of obesity in the 50~64 years age group was significantly higher than those of the other age groups. Among age groups, malnutrition was the highest in the 65-and-over age group. It appears that women in the 20~29 and 65-and-over age groups were the highest nutritional risk. The percentage of carbohydrates in total energy intake was higher and the percentages of protein and fat were lower in the 65-and-over age group than other groups. Frequency of skipping breakfast was lower in women aged 65-and-over, and moderate physical activity significantly decreased with increasing age. Awareness of dietary guidelines was higher in women aged 30~49 years than other groups, whereas it was lower in those aged 65-and-over years. Adherence to dietary guidelines of 'eating a variety of foods from each food group' was significantly lower in women aged 65-and-over years than those of other groups. However adherence to dietary guidelines of 'eating breakfast everyday with a pleasant mind' was significantly lower in women aged 20~29 years than those of other groups. Therefore, this study shows that low income women have various nutritional problems by age group, and we should support a tailored approach to improve their nutritional status.

• Journal of Nutrition and Health
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• v.52 no.2
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• pp.217-226
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• 2019

Purpose: This study examined the nutrient intake and dietary habits based on breakfast consumption in Korean adolescents. Methods: The data of the 2013 ~ 2015 Korea National Health and Nutrition Examination Survey (KNHANES) were used in this study. The analysis included 1,281 adolescents aged 12 to 18 years. The subjects were divided into two groups (EBF: eating breakfast, n = 911; SBF: skipping breakfast, n = 370). Results: The EBF group was significantly younger than the SBF group. In addition, the EBF group had a significantly lower frequency of skipping dinner than the SBF group. The EBF group consumed significantly higher levels of most nutrients except for vitamin A than the SBF group. The percent of nutrient intake under the EAR (estimated average requirements) in the EBF group were also significantly lower than that in the SBF group. Moreover, the NAR (nutrient adequacy ratio) and MAR (mean adequacy ratio) of the EBF group were significantly higher than those of the SBP group. The intake of cereal, sugars and sweeteners, vegetables, and eggs in the EBF group was significantly higher than that in the SBF group. Conclusion: The habit of skipping breakfast in adolescents leads to a decrease in the total nutrient intake and imbalanced dietary habits. Breakfast consumption in adolescence is very important. Therefore, more studies will be needed to develop nutrition education systematically in Korean adolescents.

• Geophysics and Geophysical Exploration
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• v.25 no.4
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• pp.227-241
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• 2022

Full waveform inversion (FWI) in the field of seismic data processing is an inversion technique that is used to estimate the velocity model of the subsurface for oil and gas exploration. Recently, deep learning (DL) technology has been increasingly used for seismic data processing, and its combination with FWI has attracted remarkable research efforts. For example, DL-based data processing techniques have been utilized for preprocessing input data for FWI, enabling the direct implementation of FWI through DL technology. DL-based FWI can be divided into the following methods: pure data-based, physics-based neural network, encoder-decoder, reparameterized FWI, and physics-informed neural network. In this review, we describe the theory and characteristics of the methods by systematizing them in the order of advancements. In the early days of DL-based FWI, the DL model predicted the velocity model by preparing a large training data set to adopt faithfully the basic principles of data science and apply a pure data-based prediction model. The current research trend is to supplement the shortcomings of the pure data-based approach using the loss function consisting of seismic data or physical information from the wave equation itself in deep neural networks. Based on these developments, DL-based FWI has evolved to not require a large amount of learning data, alleviating the cycle-skipping problem, which is an intrinsic limitation of FWI, and reducing computation times dramatically. The value of DL-based FWI is expected to increase continually in the processing of seismic data.