• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.53-56
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• 2008

This paper is to investigate the change of the period of hot weather concrete with elapse of age based on climate data. Climate data for 30 years and 5 years are used respectively. Determination of the period of hot weather concreting on architectural execution in Korea according to the specifications of AIJ, KSCE, and ACI are discussed. According to the research, the period of hot weather concreting with each specification in most regions lasts over 35 days. Compared with the period of cold weather concreting in hillside and inland area, coastal areas have shorter period in the same latitude. The period of hot weather concreting tends to decrease with high latitude. As expected, with the elapse of age, the period of hot weather concrete exhibited to decrease, especially, big city like Seoul, Busan etc had remarkably increased period by as much as a week. This is due to the global warming and industrialization effect with the elapse of age.

• Journal of Korean Medicine for Obesity Research
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• v.16 no.2
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• pp.116-123
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• 2016

Objectives: The purpose of this study was to investigate the effects of modified fasting therapy on the changes of body compositions. Methods: We analyzed the medical records of 33 patients, who carried out modified fasting therapy at Dunsan Korean Medicine Hospital of Daejeon University from January 1st, 2011 to December 30th, 2015. They went through reducing food intakes period (7 days), fasting period (14 days) and refeeding period (14 days). Body compositions (weight, body mass index, skeletal muscle mass, percent body fat, basal metabolic rate, waist-hip ratio, visceral fat area) were reviewed at each state. And then the data was analyzed. Results: The body composition values (weight, body mass index [BMI], skeletal muscle mass, percent body fat, basal metabolic rate, waist-hip ratio, visceral fat area) decreased during the fasting therapy period, as a whole. The weight, BMI, percent body fat and visceral fat area decreased during the reducing food intakes period, the fasting period and the refeeding period. The skeletal muscle mass and basal metabolic rate significantly decreased during the reducing food intakes period and the fasting period, and insignificantly increased during the refeeding period. Conclusions: Results from this investigation showed that modified fasting therapy using fermented herbal medicine have positive effects on changes of body compositions.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.4
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• pp.312-319
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• 2016

Measured wave data covering two years simultaneously at 3 locations along the eastern Arabian Sea reveals the presence of long-period (peak wave period > 18 s) low-amplitude waves (significant wave height < 1 m) and the characteristics of these waves are described in this article. In a year, 1.4-3.6% of the time, the low-amplitude long-period swells were observed, and these waves were mainly during the nonmonsoon period. The wave spectra during these long-period swells were multi-peaked with peak wave period around 18.2 s, the secondary peak period around 13.3 s and the wind-sea peak period at 5 s. The ratio of the spectral energy of the wind-sea peak and the primary peak (swell) was slightly higher at the northern location (0.2) than that at the southern location (0.15) due to the higher wind speed present at the northern location.

• Communications of the Korean Mathematical Society
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• v.32 no.2
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• pp.425-433
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• 2017

This paper is concerned with the analysis of the busy period distribution in a batch arrival $M^X/G/1$ retrial queue. The expression for the Laplace-Stieltjes transform of the length of the busy period is well known, but from this expression we cannot compute the moments of the length of the busy period by direct differentiation. This paper provides a direct method of calculation for the first and second moments of the length of the busy period.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.155-162
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• 2001

In this study, it was performed that the seismic response analysis using long period earthquake wave and short period earthquake wave on dynamic behavior of concrete gravity dam. The results showed that if the same magnitude earthquake waves acted on concrete dam, the maximum displacement and stress at dam crest of long period wave(0funato wave) were about 30 % larger than those of short period wave(Hachinohe wave). And the response acceleration of dam crest was amplified about 5 times in long period earthquake wave and about 3 times in short period earthquake wave.

• Journal of Preventive Medicine and Public Health
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• v.53 no.2
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• pp.67-69
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• 2020

Controversy remains over whether the coronavirus disease 2019 (COVID-19) virus may have infectivity during the incubation period before the onset of symptoms. The author had the opportunity to examine the infectivity of COVID-19 during the incubation period by conducting an epidemiological survey on a confirmed patient who had visited Jeju Island during the incubation period. The epidemiological findings support the claim that the COVID-19 virus does not have infectivity during the incubation period.

• Lingua Humanitatis
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• v.7
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• pp.335-353
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• 2005

In recent years there has been much discussion about whether there is a critical, or sensitive period for language acquisition. Research on a critical period provides an excellent example around which we can organize a discussion of the behavioral and neural evidence. In this paper, the early history of critical periods and evidence for the existence of critical periods in various domains of human cognition and learning are reviewed. Followed by this overview, evidence for a critical period in both linguistic and non linguistic area are presented. The paper then provides some unresolved questions regarding a critical period in language acquisition and states what the outcome of this issues mean for an understanding of language acquisition. Finally the paper concludes with some educational implications of a critical period for practice.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.12
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• pp.3326-3334
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• 1994

To theoretically predict knock occurrence in S. I. engine as a function of engine design and operating parameters, transient local temperature and pressure, mixture density of flame front in combustion period are calculated. We next determined normal combustion period and auto ignition period of end gas using the prediction method on occurrence of spark knock which we suggested. We predict knock occurrence in S. I. engine by comparing consecutively normal combustion period with the auto ignition period of end gas in combustion period. Engine design and operating parameters such as compression ratio, engine speed, spark timing, inlet temperature and pressure are taken into account in this calculations. The predicted result are well matched with the experimental results in turbocharged engine. Therefore, this method will provide the systematic guideline for designing engines in view of knocking limits.

• Journal of The Korean Association For Science Education
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• v.14 no.2
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• pp.111-122
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• 1994

This study tried to find the effect to the representation patterns of science concepts upon the momentum effect. The previous studies showed that the momentum effect is influenced by students' cognitive levels and the abstractness of test items. The representation patterns of science concepts are divided into 4 different types: quantitative and qualitative, verbal and image. The research method used in this study is time series design. The period is 50 days. The period is divided into "pre-lest", "intervention-test", "post-test". Pre-test period is 5 days and in this period class instruction does not exist. Intervention-lest period is 30 days and in this period class instruction exist. Post-test period is 15 days and in this period class instruction does not exist. The results showed longer momentum effect on the image-qualitative representation pattern than the other representation patterns. Qualitative concepts is formed better than quantitative. Momentum effects is not artifact but the essential characteristics of science study.

• Fashion & Textile Research Journal
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• v.5 no.4
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• pp.351-362
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• 2003

To study marketing strategy changes caused by Korea fashion industry development process, the fashion marketing strategy changes of Japan, considered as the most similar one of Korea, was compared. At each period, p! roper cost efficiency strategies, product differentiation strategies, and market segment strategies has been selected and applied. The fashion industry foundation period namely practical usage clothing period of Korea follows 10 years after one of Japan. 90's highly sensitive fashion period namely fashion industry growth period follows 5 years after one of Japan. As entering to fashion industry maturity period with global competition, the time difference falls to less than 5 years. With hosting of 2002's World-Cup, Korea's global competitiveness has increased, and it appears to be possible of being fashion market leader in East Asia and Japan's rival on an equal footing.