• Journal for History of Mathematics
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• v.24 no.3
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• pp.77-94
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• 2011

This study aims to provide a teaching strategy accommodating the symbols of the definite integral and guiding students through the meaning of notations in area and volume calculations, based on characterization as to how students comprehend the symbols used in the Riemann sum formula and the definite integral, and their interrelationship. A survey was conducted on 70 high school students regarding the historical background of integral symbols and the textbook contents designated for the definite integral. In the following analysis, the comprehension was qualified by 5 levels; students in higher levels of comprehension demonstrated closer relation to the history of integral notations. A teaching strategy was developed accordingly, which suggested more desirable student understanding on the concept of definite integral symbols in area and volume calculations.

• School Mathematics
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• v.11 no.2
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• pp.301-316
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• 2009

There are two distinct processes, definite integral and indefinite integral, in the integral calculus. And the term 'integral' has two meanings. Most students regard indefinite integrals as definite integrals with indefinite interval. One possible reason is that calculus textbooks do not concern the meaning in the relationship between definite integral and indefinite integral. In this paper we investigated the historical development of concepts of definite integral and indefinite integral, and the relationship between the two. We have drawn pedagogical implication from the result of analysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.339-348
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• 2004

This study was peformed to assess the relationships among bone mineral density (BMD), Physiological characteristics and lifestyle factors in 61 premenopausal working women aged 30∼49 y in Busan. The BMDs of the lumbar spines (Ll∼L4), femoral necks (FN), ward's triangles (WT) and trochanters (TC) were measured by dual energy X-ray absorptiometry. Data for physiological characteristics and physical activity was assessed by questionnaire and usual intakes of coffee, green tea, alcohol, Coca cola by food frequency questionnaire. The BMDs of L14, FN, WT and TC were 1.02 g/$\textrm{cm}^2$, 0.76 g/$\textrm{cm}^2$,0.69 g/$\textrm{cm}^2$ and 0.66 g/$\textrm{cm}^2$respectively The BMD of FN was assessed as osteopenia by T-score. The BMD of WT was positively correlated with age of monarch (p<0.05) and the BMD of Ll4 was positively correlated with delivery number (p<0.05). The BMD of Ll4 was positively correlated with hours of outdoor activity per weekend and week (p<0.05, p<0.05). The BMDs of FN and WT (p<0.05, p<0.05) were positively correlated with intake of green tea per month and the BMD of FN (p<0.05) was positively correlated with intake of wine per month. But the BMD of Ll (p<0.05) was negatively correlated with intake of Coca cola per month. So nutritional education for increasing hours of outdoor activity and decreasing intake frequency of beverage contributing to diminishment of bone mineral density is needed for premenopausal working women to prevent osteoporosis.

• Journal of Digital Convergence
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• v.15 no.8
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• pp.333-340
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• 2017

Timelapse is an imaging technique that captures motion at regular intervals and then projects it at normal speed. We looked at Timelapse advertising images of global brands and presented a model for analyzing components and expression methods of Timelapse, a new image technique. In previous research, literature research, Internet data survey, and YouTube data were investigated. Continuous photography has been developed as an imaging technique, and we have examined the current production status applied to domestic and foreign documentary, domestic and foreign drama, film, and advertisement. In 2015-2016, I will analyze the techniques of iPhones (2016), Ralph Lauren Polo Ads (2015), and Canon EOS (2013) videos that use Timelapse techniques in their recent advertisements. The results show that the Timelapse component is a static element, the static motif is mainly an artificial structure, the place is outdoor, the color is taken at a time showing the characteristics of the place, and the layout is all centered. The dynamic motif is a moving object. The dynamic line consists of a story based on the object. The time is about 11-15 seconds, the longest is about 1 minute and 30 seconds, and the editing is mainly focused on the product with the brand logo emphasized. In conclusion, it is the role of the image to pay attention to the advertisement and catch the eye. In order to motivate the buyer's mind, it is necessary to direct and edit such as Timelapse, which stimulates the emotions inherent in the mind and stimulates the non-verbal symbols. Future research is likely to reveal various attempts at temporal editing of images.