• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.110-120
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• 1999

Topology optimization is used for determining the best layout of structural components to achieve predetermined performance goals. In the present study, we consider that the objective function is to maximize the natural frequency of the structure for a designated mode and the constraint function is to constrain a total material usage. In this paper, using a topology optimization technique based on the homogenized material and the chessboard prevention strategy, we obtain the optimal layout and the reinforcement of an elastic structure. Several examples are presented to show the ability of the topology optimization technique used in this paper to deal with an optimal layout problem for a free vibration structure.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.21 no.1
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• pp.1-12
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• 2017

Objectives Some major Chinese medical classics like Huangdineijing (黃帝內經) and Nanjing (難經) assert that a normal person breaths 13,500 times every day. It's just half of real breathing cycles of human. So I tried to find a reasonable explanation to solve this conflict between truth and literal description. Materials and methods To find breath count descriptions in Chinese ancient books, I used Kanseki Repository (http://kanripo.org/). To find precedent research on this topic, I used China National Knowledge Infrastructure (http://cnki.net). Results 33 books refers to human breath cycles for a day, and most of them introduce 13,500 as human breathing frequency of one day. Some recent papers on Laoguanshan (老官山) Western Han dynasty manuscripts show new clues on this topic. Conclusion I assume that 13,500 cycles, the incorrect human breathing frequency of a day, might be originated from adjusting the meaning and usage of the word "Xi (息)".

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.219-222
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• 2001

The human speech sounds are use to diagnosis in oriental medicine with ‘0-sung’theory. In general, human voice are sound waves which generated by phonation. Two major parts of phonation are vocal cords and vocal tract. The uniqueness of individual vocal sound depend on structure and usage of their vocal cords and tract. In the oriental medicine, “0-sung (5-tones)” has been used to classify constitution of human body In order to characterize the “0-sung”, their frequency characteristics are investigated, and a principal frequency component is extracted. Then, the principal component is applied to classify sounds into “0-sung.”

• Journal of Korean Association for Spatial Structures
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• v.17 no.1
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• pp.93-100
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• 2017

With increasing number construction of high-rise building which has about 40 to 60 floors there have been many kinds of problem which related with usage from vibration. To predict response acceleration, it is important to assess correct natural frequency. However, due to the noise of MEMS sensor, it is difficult to measure dynamic characteristic such as natural frequency when measuring ambient vibration using MEMS sensor within cell phone. Therefore, a comparative analysis on vibration measuring applications was performed after measuring ambient vibration of 2 skyscrappers which have height between 133.5~244.3m that are located in Seoul and Observation tower using I-jishin APP with noise reduction function of MEMS sensor in order to verify the effectiveness of low noise type vibration measurement APP.

• Child Health Nursing Research
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• v.5 no.3
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• pp.329-339
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• 1999

The Purpose of this study was to take the right direction and meet the requirements of newspaper function about child health through evaluation of child health information articles in newspapers. Data were collected 4 main daily newspaper by selecting child health information articles during 1 year from January 1 to December 31, 1998. The results of this study are as follows. The frequency according to health category, disease treatment(47 7%) topped followed by health maintenanceㆍpromotion(28.8%). growthㆍdevelopment(12.1%), disease Prevention(11.4%). The frequency according to WHO international disease classification, infectious disease (23.6%) take most. In evaluation area of child health information, practical usage(3.78) topped followed by accuracy(3.68), comprehensiveness(3.64), clearness (3.48), concreteness(3.33).

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.223-225
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• 2005

This paper presents a novel prototype of a current source resonant inverter using insulated gate bipolar transistors for driving a streamer reactor, streamer generation technology has been recognized as one of the best methods for water treatment, disinfection, industrial wastes utilization, and so on. However, some technological difficulties related to efficient streamer production have been significant problems restricting streamer usage in the industrial plants. Introduced in this paper is a pulse density modulated high frequency inverter for a plasma generate, which is developed with the aim to improve power conversion and control characteristics of the streamer reactor by using advances in power electronic technology. The developed system implements the feedforward control-based pulse density modulation control scheme with pulse width modulation feedback control strategy to compensate temperature and other environmental influences on streamer discharge.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.193-198
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• 2005

The aim of this paper is to exam why the nouns that used /kh, ph, ts, th/, as the final phoneme changed. Assuming that these change related to the aspects of the word usage, we collected the word frequency and the phonetic form of words. The results are as follows : ① The realization of standard phonetic form is related to the frequency of case marker that could not be omitted, combined with the word. ② The changing into /s/ in a coronal consonant is related to the case marker [i].

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.737-741
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• 2000

Portable communication devices such as laptop computers suffer impact-induced failure in their usage. Drop/impact performance of these products is one of important concerns of product design. Because of the small size of this kind of electronics products, it is very expensive, time-consuming and difficult to conduct drop tests to directly detect the failure mechanism and identify their drop behaviors. Finite element analysis provides a vital, powerful vehicle to solve the problems. The models are created with HYPERMESH, and the analysis is carried out with LS-DYNA3D. The analysis is focused on HDD impact behavior in acceleration peak values.

• Nutrition Research and Practice
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• v.18 no.5
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• pp.674-686
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• 2024

BACKGROUND/OBJECTIVES: Mukbang, a trend originating in South Korea and gaining global popularity, could influence children's food choices and eating habits. This study analyzed the correlation between Mukbang viewing time in children and adolescents, their meal consumption frequency, nutrition quotient (NQ), and frequency of food intake. SUBJECTS/METHODS: From July to August 2022, this cross-sectional study investigated upper elementary students (ages 9-11 yrs) and adolescents (aged 12-18 yrs) using an online survey. The survey items included key demographic factors, Mukbang viewing frequency and duration, frequency of main meal consumption, commonly consumed foods, and the validated NQ, which was used to assess food intake quality. Multiple linear regression analysis was used to explore the link between Mukbang viewing and nutritional habits. RESULTS: Weekly Mukbang viewing time was significantly correlated with eating habits after adjusting for gender, age, physical activity frequency past week, household income, and primary caregiver's level of education. Increased Mukbang viewing time correlated with reduced frequency of breakfast (P for trend < 0.001) and dinner (P for trend = 0.012), while the frequency of eating out (P for trend < 0.001) and late-night snacking (P for trend = 0.008) increased. Higher Mukbang viewing time notably decreased scores in the moderation domain (P for trend < 0.001), in the practice domain (P for trend = 0.031), and overall NQ (P for trend < 0.001). It also significantly elevated intake of sweets (P for trend = 0.001), Korean-style street food, Western-style fast food, instant noodles, sweetened beverages, caffeinated beverages, and fruit and vegetable juices (P for trend < 0.001). CONCLUSION: This study identifies a negative correlation between Mukbang viewing and eating habits among Korean children and adolescents. The results indicate the importance of incorporating children and adolescents' media usage and environmental factors on dietary education and the development of policy programs.

• Journal of the Korea Furniture Society
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• v.26 no.1
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• pp.61-70
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• 2015

There is an increasing trend each year in the number of subway users due to increase in the traffic volume. As the number of train service has risen, the subway drivers are given heavy work and from the same, are put at risk of mental health deterioration due to stress. As this is directly connected to safety, there is an urgent need for improvement of the situation. Therefore, as a way to appropriately relieve such stress, resting space where mental and physical energy can be recharged is necessary. Thus, this research conducted a survey of demand with subway drivers as subjects in order to provide resting space that can offer healthy rest and increase work effectiveness. 50 subway drivers were the subjects of this survey. As a result of analyzing the contents of the survey, environmental satisfaction was shown to be the lowest compared to psychological and morphological satisfaction. In the case of sleeping room, they wanted more comfortable and individual space. And the waiting room had the highest rate of usage frequency. The storage space was where the subway drivers showed the strongest attachment and was shown to be the only personal space. Most were shown to be satisfied with the outdoor space, but it had the lowest usage frequency. In addition, it is nessasery customized storage cabinet designed for subway drivers should be produced, which can effectively arrange the limited space. I hope that these direction of improvement can increase the healthy rest and work effectiveness of the locomotive engineers as it is directly being connected to the health and safety of the citizens.