• Journal for History of Mathematics
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• v.28 no.6
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• pp.301-310
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• 2015

Since Jiuzhang Suanshu, the main tools in the theory of right triangles, known as Gougushu in East Asia were algebraic identities about three sides of a right triangle derived from the Pythagorean theorem. Using tianyuanshu up to siyuanshu, Song-Yuan mathematicians could skip over those identities in the theory. Chinese Mathematics in the 17-18th centuries were mainly concerned with the identities along with the western geometrical proofs. Jeong Yag-yong (1762-1836), a well known Joseon scholar and writer of the school of Silhak, noticed that those identities can be derived through algebra and then wrote Gugo Wonlyu (勾股源流) in the early 19th century. We show that Jeong reveals the algebraic structure of polynomials with the three indeterminates in the book along with their order structure. Although the title refers to right triangles, it is the first pure algebra book in Joseon mathematics, if not in East Asia.

• Journal of Engineering Education Research
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• v.1 no.1
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• pp.80-85
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• 1998

Yak-yong Jung discussed technology for the first time in Korea, 195 years ago, in his [Ki-ye-lon](the Theory of Techne: 1802) in which he investigated the essence and the developmental aspect of technology and the ways to promote technology. As a man of the 19th century when the West was being transformed into an industrial society by the Industrial Revolution, Jung suggested various ways to reform his nation an agricultural society. Although they were not accepted by the Dynasty, consideration of the social and economic situation and the world history at that time shows that they were very innovative. This study aims at defining Jung's view of technology, centering around [Ki-ye-lon](the Theory of Techne), and discusses what the technological education should emphasize in the future, that is to say: mathematical and scientific principles, the utility of technology, its developmental aspect, technological policy.

• Journal for History of Mathematics
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• v.32 no.3
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• pp.97-108
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• 2019

This paper is an outgrowth of a study on recent papers and presentations of Hong Sung Sa, Hong Young Hee and/or Lee Seung On on Gugo Wonlyu which is believed to be written by the famous Joseon scholar Jeong Yag-yong. Most of what is discussed here is already explained in these papers and presentations but due to brevity of the papers it is not understood by most of us. Here we present them in more explicit and mathematical ways which, we hope, will make them more accessible to those who have little background in history of classical Joseon mathematics. We also explain them using elementary projective geometry which allow us to visualize Pythagorean polynomials geometrically.

• Journal for History of Mathematics
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• v.29 no.5
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• pp.257-266
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• 2016

This paper is a sequel to our paper [3]. Although polynomials in the tianyuanshu induce perfectly the algebraic structure of polynomials, the tianyuan(天元) is always chosen by a specific unknown in a given problem, it can't carry out the role of the indeterminate in ordinary polynomials. Further, taking the indeterminate as a variable, one can study mathematical structures of polynomials via those of polynomial functions. Thus the theory of polynomials in East Asian mathematics could not be completely materialized. In the previous paper [3], we show that Jeong Yag-yong disclosed in his Gugo Wonlyu(勾股源流) the mathematical structures of Pythagorean polynomials, namely polynomials p(a, b, c) where a, b, c are the three sides gou(勾), gu(股), xian(弦) of a right triangle, respectively. In this paper, we show that Jeong obtained his results through his recognizing Pythagorean polynomials as polynomial functions of three variables a, b, c.

• (The)Study of the Eastern Classic
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• no.48
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• pp.289-310
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• 2012

The present study analyzes the content of "Suojaegi (The Account of the Suo Residence)," an essay written by the Joseon-dynasty scholar Jeong Yak-yong (丁若鏞, 1762-1836). The study identifies the work's characteristic features and significance, seeking to develop a methodology to use this essay to teach students how to write. In terms of its content, the author of "Suojaegi" asserts what it means to "protect one's self-integrity" as the word "Suo" means in the title of the residence where the author's brother Jeong Yak-hyeon(丁若鉉) lived. According to the author, his elder brother could keep on living in his house, without being sent to exile in the political turmoils, because he preserved his sense of self and adhered to his principles. The originality of the essay is attributed to the use of gi (記), a genre of writing in classical Chinese that can be translated as "record," or "account," to express his thoughts in a place of exile in the form of a dialogue with his own self. Lastly, this self-reflective essay can be served as a guide for teaching students to make their own pen names, and to write a letter of self-introduction.

• (The)Study of the Eastern Classic
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• no.59
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• pp.297-324
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• 2015

This article discusses Dasan Cheong Yagyong(1762-1836)'s perspectives on The Book of historical documents("書經"). Dasan Cheong Yagyong considered The Shoo King as The Book of historical documents presented Ideas of Confucian Politics in ancient China. Many Scholar and Kings dispersed and re-edition The Shoo King as historical documents. Dasan Cheong Yagyong analyzed, de-constructed, and reinterpretations documents of dominant The Shoo King. Dasan Cheong Yagyong tried to recover the original documents The Shoo King. Dasan Cheong Yagyong collected dispersed material of The Shoo King, and complied the original documents. Dasan Cheong Yagyong wrote four book of The Shoo King. Dasan want to reconstruct the new theory by these reinterpretations of The Book of historical documents presented Ideas of Confucian Politics in ancient China, and to open new era.

• Journal of Korean Philosophical Society
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• v.139
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• pp.213-238
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• 2016

This paper examines how Dasan Jeong Yak-yong developed self-healing and his perspective of happiness during the hardest point of his political and social career. Just after the death of King Jeongjo (正祖, reign. 1766-1800) the arrest and persecution of those who accepted Christian knowledge from the West began. Among them were Jeong's family members and friends. Jeong, who had learned but had not accepted Christianity as a religious belief, was exiled to Ganggin 康津 in southern Jeolla Province where he was to spend the next 18 years. The two things that helped Jeong through his exile were the Book of Changes 易經 and his commitment to the study of Confucian thought, political, and social reforms. His life-long commitment to writing and his progressive understanding of the principle of changes of the universe in the Book of Changes, represented processes of self-healing and cultivation, depriving Jeong of self-pity and enabling him to attain the highest level in self-realization. According to Jeong, there are two kinds of happiness; "secular happiness" (yeolbok 熱福) related to power and wealth, and "pure happiness" (cheongbok 淸福), a free and idyllic life. For Jeong, the latter was more valuable than the former. Jeong believed that life pursing ethical virtues only could bring authentic joy to people. Furthermore, his devotion to the issues of systematic, social reforms was out of his desire to bring the public happiness by "practical learning", silhak 實學.

• (The)Study of the Eastern Classic
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• no.32
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• pp.159-187
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• 2008

This article aims to investigate the change of theories of reading and its historical meaning in the later Joseon period. Three scholar who left major theories of reading are mainly analyzed for the sake of it. Park, Se-chae(1631-1695) was a Neo-Confucianist who had the theory of reading named Dokseo-Gungliron(讀書窮理論). It was totally based on the scheme of Neo-Confucianist instruction and concentrated on mastering the moral principles with relishing the sentences of the Confucian Canons. Jeong, Yak-yong(1762-1836) was a Practical learning scholar and then criticized the moral-centric theory of reading of Neo-Confucianism. He valued much of the Confucian Canons but also focused on erudite reading so as to enlarge practical knowledge. Hong, Gil-ju(1786-1841) was a stylist and presented a severe criticism against Neo-Confucianist theory of reading as much. He thought that what we could realize with reading are the principles of the individual, not of the whole. The change of theories of reading in the later Joseon period as above reveals us the fact that the intellectual history of that period was in the process of dynamical change.

• Journal of the Daesoon Academy of Sciences
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• v.50
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• pp.139-176
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• 2024

This article examines the theory of mutual resonance (感應論) of Dasan (茶山), Jeong Yak-yong (丁若鏞), and Jeungsan (甑山), Kang Il-sun (姜一淳), who lived during the transition to modernity in Joseon. By examining the philosophical thought of Dasan and Jeungsan, which centered on the problem of realizing morality through the resonance (感應) between human beings and Sangje, this article aims to reveal that their religious discussion of resonance, which is differentiated from the rational theory, ultimately strengthens the practice of morality. Dasan and Jeungsan argue that it is difficult to overcome human selfish desires through the mind alone, which aims for moral autonomy, so the recognition of a transcendent being, Sangje, becomes necessary. Since Sangje, the Supreme Being, is always watching over human life, one can examine one's deficiencies with reverence and correct them. In particular, Dasan and Jeungsan reveal that humans and Sangje do not exist independently, but are in touch with each other through the heart, so that moral practice can be actualized in reality. Dasan and Jeungsan do not position humans and the Supreme Being as independent entities, but rather allow them to organically resonate with each other through the mind, enabling individuals to engage in moments of contemplation and reflection at every juncture of choice, unbound by time and space. From this perspective, the resonance theory of Dasan and Jeungsan can be seen to have practical implications for integrating moral practice into everyday life. The thought systems of Dasan and Jeungsan should be understood as embodying the anguish and sincerity of two figures who sought to convey to future generations the path of moral practice that humans must walk, based on a reverent mindset towards the Supreme Being, amidst tumultuous domestic and international circumstances.

• Korean Educational Research Journal
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• v.40 no.2
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• pp.17-33
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• 2019

This study examines the fundamental ethics of practice that Dasan Jung Yak-yong(1762-1836) argued at the book, "Dàxuégōngyì大學公議, The Public debate of Great Learning", by investigating the relationship between main agents of education. "Dàxuégōngyì", the book that Dasan wrote when he was 53 years old at his exiled place, Gangjin. As the title suggested, Dàxuégōngyì, it could be recognized as the impartial view based on the critical perspective to Zhūxǐ(朱憙)'s opinion. Zhuxi focused on the importance of "Great Learning 大學" as a study of the Great people and argued that "Great Learning" is the study for all the people should learn. On the other hand, Dasan claimed that "Tàixuézhīdào太學之道" in "Great Learning" is the study for the prince, not for the normal people. And he also interpreted "Dàxué 大學" as the school for teaching prince. In addition, "Great Learning" suggested the three practical principles; to illustrate illustrious virtue; to renovate the people; and to rest in the highest excellence. However, Dasan argued different way and emphasized three ethics of practice; filial piety(孝), admiration(弟), mercy(慈) and regarded as illustrious virtue of "Great Learning." He denied the three principle of "Great Learning" that Zhuxi reorganized and suggested including renovating the people(新民), and provided that close to the people(親民) is one of the main principles of "Great Learning." According to Dasan, if the king practices these three ethics of practice including filial piety, admiration, and mercy, so that the people will practice these ethics voluntarily. In other words, he indicated that the practice of three ethics is not only for the prince in the loyal family, but also for principles to educate the people in the nation. Thus, three ethics by Dasan including filial piety, admiration, and mercy could be recognized as the symbol of humanity. In other words, Dasan's three ethics in "Great Learning" can be recognized as the practical principles including educational issues and educational interactions. If these three ethics can be referred as the symbol of humanity as mentioned above, the implicit educational interactions are specifically constructed within the basic assumptions. Therefore, it is possible to clarify the specific ethics of practice by the indicating specific subjects and objects in the educational interactions between these three ethics of practice. Also, it helps more clear comprehension about the "Dàxuégōngyì大學公議, The Public debate of Great Learning", by Dasan.