• Journal for History of Mathematics
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• v.22 no.4
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• pp.1-14
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• 2009

Since western mathematics and astronomy had been introduced in Chosun dynasty in the 17th century, most of Chosun mathematicians studied Shu li jing yun(數理精蘊) for the western mathematics. In the last two decades of the 19th century, Chosun scholars have studied them which were introduced by Japanese text books and western missionaries. The former dealt mostly with elementary arithmetic and the latter established schools and taught mathematics. Lee Sang Seol(1870~1917) is well known in Korea as a Confucian scholar, government official, educator and foremost Korean independence movement activist in the 20th century. He was very eager to acquire western civilizations and studied them with the minister H. B. Hulbert(1863~1949). He wrote a mathematics book Su Ri(數理, 1898-1899) which has two parts. The first one deals with the linear part(線部) and geometry in Shu li jing yun and the second part with algebra. Using Su Ri, we investigate the process of transmission of western mathematics into Chosun in the century and show that Lee Sang Seol built a firm foundation for the study of algebra in Chosun.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.701-705
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• 1992

The effect of different boiling methods(with distilled water, 1% salt added water and 1% sodium bicarbonate added water) on the physicochemical properties of Su Ri Chwi (Synurus palmatopinnonatifidus var. indivisus KITAM.) were investigated. The addition of 1% sodium bicarbonate (baking soda) to the boiling water resulted in an increase in the pH of effluent. The green value of cooked Su Ri Chwi was simillar to the raw material. Su Ri Chwi cooked in 1% sodium bicarbonate added for 10minutes retained higher chlorophyll and vitamin C contents than those of Su Ri Chwi treated in distilled water and 1% salt water for 30minutes. 70% of the water-soluble proteins in raw Su Ri Chwi was albumin. However, albumin was decreased by the method used. The contents of glutelin, globulin, and prolamin were increased by the cooking, vice versa. The contents of NDF, ADF, cellulose, and lignin were decreased regardless of the method used, on the other hand, the content of hemicellulose was increased.

• Korean journal of food and cookery science
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• v.9 no.1
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• pp.19-24
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• 1993

The purpose of this study was to investigate the physicochemical properties of Su Ri Chwi (Synurus Palmatopinnonatifidus var. indivisus KiTAM.) cooked in different solution (distilled water, 1%, salt and 1% sodium bicarbonate added water) and time. The content of crude fiber showed the highest percentage among the alcohol-insoluble solids of cooked Su Ri Chwi. The contents of Ca and Mg were decreased by the addition of 1% sodium bicarbonate. The main neutral sugars of alcohol insoluble solids were arabinose, galactose, and glucose. The content of glucose was increased regardless of method used. The main neutral sugars of crude pectins were rhamnose, arabinose and glucose. Galactose was increased by the cooking. The gel chromatography on Sepharose CL-4B indicated that the pectin extracted from cooked Su Ri Chwi had lower molecular weight distribution than that of the raw Su Ri Chwi. Total pectin was decreased by the cooking method used. The amounts of soluble pectins of Su Ri Chwi cooked in 1% sodium bicarbonate added water were lower than those of raw material.

• Journal for History of Mathematics
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• v.19 no.2
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• pp.25-46
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• 2006

We investigate the process of western mathematics into Chosun and its influences. Its initial and middle stages are examined by Choi Suk Jung(崔錫鼎, $1645\sim1715$)'s Gu Su Ryak(九數略), Hong Jung Ha(洪正夏, $1684\sim?$)'s Gu Il Jib(九一集) and Hwang Yun Suk(黃胤錫, $1719\sim1791$)'s I Su Shin Pyun(理藪新編), Hong Dae Yong(洪大容, $1731\sim1781$)'s Ju Hae Su Yong(籌解需用), respectively. Western mathematics was transmitted for the study of the Shi xian li(時憲曆) when it was introduced in Chosun. We also analyze Su Ri Jung On Bo Hae(數理精蘊補解, 1730?) whose author studied $Sh\grave{u}\;l\breve{i}\;j\bar{i}ng\;y\grave{u}n$ most thoroughly, in particular for astronomy, and finally Lee Sang Hyuk(李尙爀, $1810\sim?$), Nam Byung Gil(南秉吉, $1820\sim1869$) who studied together structurally western mathematics.

• Journal of Environmental Science International
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• v.32 no.5
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• pp.303-313
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• 2023

In this study, the hydraulic gradient was calculated using the groundwater level and rainfall observed in the Hyogyo-ri area for a year, and the change in the hydraulic gradient according to the rainfall was analyzed. It was found that the groundwater level increased as the rainfall increased in all groundwater wells in the research site, and the groundwater level rise decreased as the altitude of the groundwater well increased. The hydraulic gradient in the research site ranged from 0.016 to 0.048, decreasing during rainfall and increasing after the end of the rainfall. As the rainfall increased, the groundwater level rise in the low-altitude area was more than the high-altitude area, and the hydraulic gradient decreased due to the difference in groundwater level rise according to the altitude. Through this study, it was found that the influence of rainfall is dominant for the fluctuation of the hydraulic gradient in the unconfined aquifer.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1466-1474
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• 2007

In large station with high density traffic, trains is hardly controlled by CTC but by station dispatcher because CTC has difficulties in monitoring all states of affairs happening within the station such as departs and arrivals of many trains from different lines and shunting trains between yards and platforms, etc. Therefore station dispatcher has to make quick decision about how to schedule all trains including trains to arrive and depart before long. And such decisions become harder when an unexpected delay occurs. This study suggests a mathematical model and algorithm about how to detect in advance and resolve efficiently the conflicts occurring within a station and it will be shown how to reduce delay using our approach by means of analysing the schedule of ChyungRyangRi station.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.202-202
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• 2019

상수관망 시스템의 목적은 수요자에게 양적으로 안정하고 질적으로 안전한 용수를 적정 수압으로 공급하는 것이다. 그러나, 상수관망 시스템은 노후화, 시공 중 파손 등 다양한 내 외적 요인들에 의해 파괴가 불가피하며, 이를 복구하는 과정에서 단수는 필연적으로 발생하게 된다. 단수피해를 효율적으로 감소시키는 방법은 인근 배수블록과의 비상연계를 실시하는 것이다. 비상연계란, 관망의 파손 등 비정상상황 발생 시 단수구역에 용수를 공급하기 위해, 인접한 배수블록과 연결된 비상관로를 운용하여 인접 배수블록으로부터 단수구역에 용수를 공급하는 것을 의미한다. 본 연구에서는 비상연계 시 연계공급을 실시하는 배수블록에서의 문제점이 아닌 연계공급을 받는 배수블록에서의 문제점을 실제 A시 관망을 바탕으로 분석하고, 이에 대한 해결책을 제안하였다. 실제 A시에서는 직경 600mm 간선관로(수지식)의 파손으로 2지 배수블록 하단부가 단수되는 사고가 발생하였다. 이에 단수피해를 최소화하고자 인근 배수블록인 1지 배수블록과의 비상연계를 실시하였으나, 2지 배수블록 하단부의 말단부분에서 고압이 발생하고 관로 파손과 같은 추가적인 문제가 발생하였다. 본 연구에서는 A시에서 실시한 비상연계 시나리오를 구축한 후 수원에서의 유한함을 고려할 수 있는 A-PDA 기반 수리해석을 실시하여 대한 고압발생의 원인을 분석하였다. 고압 문제의 원인은 연계 공급을 실시하는 1지 배수블록과 2지 배수블록간의 고도차에 의해 발생한 것으로 사료되며, 이에 대한 해결책으로 감압밸브 추가 설치, 주요 관로 복수화 방안을 제시하였다. 이후 각 해결책에 따른 모델을 구축한 후 수리해석을 실시하여 해결책이 상수관망에 미치는 영향을 분석하였다. 본 연구는 실제 관망에서 비상연계 시 발생한 문제를 분석함으로써 비상연계 시스템 구축 시 추가적으로 발생 가능한 문제 및 해결방안을 제안하였다.

• Journal of Korea Water Resources Association
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• v.51 no.11
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• pp.977-987
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• 2018

The purpose of the water distribution system is gradually changing to increase the flexibility for responding to various abnormal situations. In addition, it is essential to improve resilience through preparing emergency plans against water supply failure. The most efficient way is emergency interconnections which supply water from interconnected adjacent blocks. To operate successful interconnections, it is essential to evaluate the supply performance in spatial and temporal aspects. The spatial and temporal aspects are dominated by its interconnected pipes and interconnected reservoirs respectively. In this study, an emergency interconnection scenario where problem occurred in reservoir 1 at 0:00hr in A city, Korea. An Advanced-Pressure Driven Analysis model was used to simulate the volume and inflow volume of the interconnected reservoirs. Based on the hydraulic analysis results, a multi-dimensional evaluation of the supply performance was conducted by applying possible water supply range indicator (PWSRI) and possible water supply temporal indicator (PWSTI) which are based on fuzzy membership functions. As a result, it was possible to evaluate the supply performance on the sides of consumers in spatio-temporal aspects and to review whether established plans mitigate the damage as intended. It is expected to be used for decision making on structural and non-structural emergency plan to improve the performance of an emergency interconnection.

• Journal of Family Resource Management and Policy Review
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• v.19 no.2
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• pp.75-99
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• 2015

The purpose of this study was to examine the career-interrupted lives of highly educated career-interrupted women. The participants were 11 women in their thirties who had graduated from university graduated and had a child. We collected the qualitative data using a focused group interview. The results of this study can be summarized as follows. First, in personal histories of the career-interrupted women, there were marriages and births, difficulties with child care, priority placed on the family, pressure to retire, and an absence of a layoff system related to births and child care. Second, with regard to their interrupted lives, while there was comfort and an absence of work-stress, there was child care stress, financial stress, anxiety due to career uncertainty, a loss of the social self, depression, emptiness, low self-esteem, dependence on husbands, regret, conflict in career choices, and envy of childcare support. Third, their reasons for seeking reemployment included the financial benefits, increased independence, self-realization in their job, hope for a stable job, self-management, and hope for a social network.

• Journal of Conservation Science
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• v.37 no.6
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• pp.617-625
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• 2021

Daegokcheon Stream in Daegok-ri, Ulju-gun, is an area with a developed valley and bedrock from Gajisan Provincial Park to the confluence of the Taehwa River across the Yangsan Fault. To measure the rock of Bangudae petroglyphs, the mineralogical weathering, joints, and scours or cavities at the bottom were confirmed. The measurement was carried out for a short period of time on the joint of the bedrock on which the Bangudae petroglyphs were engraved. Compared to the measured value obtained using existing optical fiber (Ch4 150 ㎛), a displacement value of 300 ㎛ was obtained using the non-attached, non-contact type of measuring instrument. In the future, it is inferred that this instrument could be used for various cultural properties if the HSV-value suitable for illuminance and various measurement experiences are stored.