• Journal for History of Mathematics
• /
• v.24 no.1
• /
• pp.1-13
• /
• 2011

In Tian mu bi lei cheng chu jie fa(田畝比類乘除捷法) of Yang Hui suan fa(楊輝算法)), Yang Hui annotated detailed comments on the method to find roots of quadratic equations given by Liu Yi in his Yi gu gen yuan(議古根源) which gave a great influence on Chosun Mathematics. In this paper, we show that 'Zeng cheng kai fang fa'(增乘開方法) evolved from a process of binomial expansions of $(y+{\alpha})^n$ which is independent from the synthetic divisions. We also show that extending the results given by Liu Yi-Yang Hui and those in Suan xue qi meng(算學啓蒙), Chosun mathematican Hong Jung Ha(洪正夏) elucidated perfectly the 'Zeng cheng kai fang fa' as the present synthetic divisions in his Gu il jib(九一集).

• Journal for History of Mathematics
• /
• v.31 no.6
• /
• pp.273-289
• /
• 2018

The KaiFangFa開方法 of traditional mathematics was completed in ${\ll}$JiuZhang SuanShu九章算術${\gg}$ originally, and further organized in Song宋 $Yu{\acute{a}}n$元 dinasities. The former is the ShiSuoKaiFangFa釋鎖開方法 using the coefficients of the polynomial expansion, and the latter is the ZengChengKaiFangFa增乘開方法 obtaining the solution only by some mechanical numerical manipulations. ${\ll}$SanHak JeongEui算學正義${\gg}$ basically used the latter and improved the estimate-value array by referring to the written-calculation in ${\ll}$ShuLi JingYun數理精蘊${\gg}$. As a result, ZengChengKaiFangFa was more refined so that the KaiFangFa algorithm is more consistent.

• ETRI Journal
• /
• v.10 no.4
• /
• pp.3-3
• /
• 1988

• Journal of Environmental Science International
• /
• v.15 no.1
• /
• pp.1-7
• /
• 2006

The purpose of this study is to illustrate the characteristics of soil organic matter (SOM) and partition coefficient $(K_{DOC})$. Humic substances (HS) from eight soils of varying properties were extracted by two different methods. The dissolved organic carbon (DOC) concentration was stabilized in 22hrs. The ratio of UV absorbance at 465nm and 665nm (E4/E6 ratio) for HS were similar pattern for 8 soils. The extraction with increasing pH increased dissolution of SON. The ratio of organic carbon (OC) associated with HA and FA (the HA:FA ratio) was varied widely in accordance with the soils and was highly correlated to OC $content(\%)$ of the soils. in modeling metal speciation in soils and soil solutions, assumptions that all DOC in soil solution is associated with FA and that HA:FA ratio in SOM is constant have been made. The results of this study indicate that the validity of these assumptions is questionable. By sequential pH extraction, the $K_{DOC}$ showed in a linear correlation with pH.

• Journal for History of Mathematics
• /
• v.22 no.4
• /
• pp.29-40
• /
• 2009

we know that Zeng Cheng Kai Fang Fa is the generalization of the method of square roots and cube roots of ancient through the investigation of China mathematics. In this paper, we have research on traditional solutions equations of China mathematics and the development solutions of equations used by Chosun mathematicians.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.24 no.4
• /
• pp.446-452
• /
• 2014

Objective: This study aimed to evaluate the exposure status of formaldehyde(FA) among the nurses in ambulatory care departments of university hospital. Methods: Two university hospitals were surveyed. The FA concentration in air were measured to target 62 nurses in 8 ambulatory care departments(89 samples). Air sampling and analysis of FA were carried out according to the OSHA Method ID-205. The survey was conducted with questionnaire asking about how to control FA and whether the nurses use the formaldehyde protectors or not. Results: FA was detected in all samples. The maximum concentration of FA was 0.258 ppm and the geometric mean was 0.023 ppm. There was no sample that exceeded any of exposure standards by OSHA-TWA whereas there were 54 samples(60.7%) that exceeded the standards by NOISH-TWA. Among 62 nurses handling FA, 13 nurses(21.0%) used the protective gloves while nobody used a gas mask. It was assessed that any of 8 common ambulatory care departments did not use a safety cabinet for FA in which local exhaust ventilation was fixed. Conclusions: Nurses in ambulatory care departments were exposed to FA. Therefore, the environment management of a workplace, the health management of a nurses, FA handling education and installing a FA cabinet with a local exhaust ventilation were needed because FA as a carcinogen was able to cause any cancer to a human body if it was emitted in air for long time.

• Journal for History of Mathematics
• /
• v.28 no.2
• /
• pp.73-83
• /
• 2015

In this paper, we give answers to some interesting questions about a Confucian scholar and mathematician in the late Joseon Dynasty, CHOI Seok-Jeong(崔錫鼎, 1646-1715), who was inducted into the Science and Technology Hall of Fame (http://kast.or.kr/HALL) for his mathematical achievements in October, 2013. In particular, we discover that CHOI Seok-Jeong was able to devote his natural abilities and time to do research on mathematics, and that he frequently communicated with his friend and fellow scholar, LEE Se-Gu(李世龜, 1646-1700), who was an expert on the astronomical calendar and mathematics, based on at least 24 letters between the two.

• Journal of Korean Library and Information Science Society
• /
• v.27
• /
• pp.171-209
• /
• 1997

The results of the study can be summarized as follows. The Shu-mu Da-wen was selected and compiled by Zhang Zhi Dong at the end of Qing Dynasty as a reading list for students preparing for the state examination and for the purpose of choosing the best from several versions. Whether it was compiled and edited by Zhang was in dispute. But it is almost certain that Zhang was the main editor because Shu-mu Da-wen showed his political, educational and scientific thoughts and knowledge distinctively. The followings are characteristics of Shu-mu Da-wen being compared with Si-ku Quan-shu Zong-mu Ti-yao. 1. In Jing-bu, the Confucian classics are divided into Zheng-jing Zheng-zhu and 'Lie-chao Jing-zhu Jing-shuo Jing-ben kao-zheng. Zheng-shi lei is divided into Zheng-shi fen he ke ben and Zheng-shi zhu bu biao pu kao-zheng. It is the special sorting method to include Du-ben lei in Jing-bu and Chu xue du-ben in Bie-lu in order to provide first learners for reading order. 2. Shi-bu included Gu-shi newly and Di-li lei is divided into Gu Di-li and Jin di-li in Shi-bu. Tian-wen Suan-fa lei is divided into Zhong-fa and Xi-fa in Zi-bu. Zhang distinguished between old books and contemporary ones to find out the origin and include newly published books in the East and the West. 3. Zhou-Qin zhu-zi is newly added to Zi-pu. In Ji-pu, Bie-ji and Zong-ji are categorized according to their style and period respectively. This show the new sorting method which added classifying system concerning academic development. It is the prominent feature in the compiling system to make Bie-lu and Cong-shu respective chapters. With those characteristics the Shu-mu Da-wen had been edited and published several times. It had a wide effect not only on compiling methods of cataloging afterwards and but also on classification systems before decimal classification was introduced in China.

• Journal for History of Mathematics
• /
• v.24 no.3
• /
• pp.1-12
• /
• 2011

It is well known that the sexagesimal cycle(干支) has been playing very important role in ordinary human affairs including astrology and almanacs and the arts of divination(術數). Yin-Yang school related the cycle with the sixty four hexagrams and the system of five notes(五音) and twelve pitch-pipes(十二律), and the processes to relate them are called respectively NaJia(納甲) and NaYin(納音) and quoted in Shen Kuo's Meng qi bi tan(夢溪筆談, 1095). Yang Hui obtained the process NaYin in the context of mathematics. In this paper we show that Yang Hui introduced the concept and notion of functions and then using congruences and the composite of functions, he could succeed to describe perfectly the process in his Xu gu zhai qi suan fa(續古摘奇算法, 1275). We also note that his concept and notion of functions are the earliest ones in the history of mathematics.

• Journal for History of Mathematics
• /
• v.22 no.4
• /
• pp.15-28
• /
• 2009

In this paper, we study the 17th Century Chosun's mathematics book ${\ll}$Muk Sa Jib San Beob${\gg}$ written by Chosun's mathematician Kyeong Seon Jing. Our study of thebook shows the ${\ll}$Muk Sa Jip San Beop${\gg}$ as an important 17th Century mathematics book and also as a historical data showing the mathematical environment of 17th Century Chosun.