• The Mathematical Education
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• v.24 no.2
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• pp.48-73
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• 1986

Though the tradition of Korean mathematics since the ancient time up to the 'Enlightenment Period' in the late 19th century had been under the influence of the Chinese mathematics, it strove to develop its own independent of Chinese. However, the fact that it couldn't succeed to form the independent Korean mathematics in spite of many chances under the reign of Kings Sejong, Youngjo, and Joungjo was mainly due to the use of Chinese characters by Koreans. Han-gul (Korean characters) invented by King Sejong had not been used widely as it was called and despised Un-mun and Koreans still used Chinese characters as the only 'true letters' (Jin-suh). The correlation between characters and culture was such that, if Koreans used Han-gul as their official letters, we may have different picture of Korean mathematics. It is quite interesting to note that the mathematics in the 'Enlightenment Period' changed rather smoothly into the Western mathematics at the time when Han-gul was used officially with Chinese characters. In Koryo, the mathematics existed only as a part of the Confucian refinement, not as the object of sincere study. The mathematics in Koryo inherited that of the Unified Shilla without any remarkable development of its own, and the mathematicians were the Inner Officials isolated from the outside world who maintained their positions as specialists amid the turbulence of political changes. They formed a kind of Guild, their posts becoming patrimony. The mathematics in Koryo significant in that they paved the way for that of Chosun through a few books of mathematics such as 'Sanhak-Kyemong', 'Yanghwi-Sanpup' and 'Sangmyung-Sanpup'. King Sejong was quite phenomenal in his policy of promotion of mathematics. King himself was deeply interested in the study, createing an atmosphere in which all the high ranking officials and scholars highly valued mathematics. The sudden development of mathematic culture was mainly due to the personality and capacity of king who took anyone with the mathematic talent into government service regardless of his birth and against the strong opposition of the conservative officials. However, King's view of mathematics never resulted in the true development of mathematics perse and he used it only as an official technique in the tradition way. Korean mathematics in King Sejong's reign was based upon both the natural philosophy in China and the unique geo-political reality of Korean peninsula. The reason why the mathematic culture failed to develop continually against those social background was that the mathematicians were not allowed to play the vital role in that culture, they being only the instrument for the personality or politics of the king. While the learned scholar class sometimes played the important role for the development of the mathematic culture, they often as not became an adamant barrier to it. As the society in Chosun needed the function of mathematics acutely, the mathematicians formed the settled class called Jung-in (Middle-Man). Jung-in was a unique class in Chosun and we can't find its equivalent in China or Japan. These Jung-in mathematician officials lacked tendency to publish their study, since their society was strictly exclusive and their knowledge was very limited. Though they were relatively low class, these mathematicians played very important role in Chosun society. In 'Sil-Hak (the Practical Learning) period' which began in the late 16th century, especially in the reigns of Kings Youngjo and Jungjo, which was called the Renaissance of Chosun, the ambitious policy for the development of science and technology called for. the rapid increase of he number of such technocrats as mathematics, astronomy and medicine. Amid these social changes, the Jung-in mathematicians inevitably became quite ambitious and proud. They tried to explore deeply into mathematics perse beyond the narrow limit of knowledge required for their office. Thus, in this period the mathematics developed rapidly, undergoing very important changes. The characteristic features of the mathematics in this period were: Jung-in mathematicians' active study an publication, the mathematic studies by the renowned scholars of Sil-Hak, joint works by these two classes, their approach to the Western mathematics and their effort to develop Korean mathematics. Toward the 'Enlightenment Period' in the late 19th century, the Western mathematics experienced great difficulty to take its roots in the Peninsula which had been under the strong influence of Confucian ideology and traditional Korean mathematic system. However, with King Kojong's ordinance in 1895, the traditional Korean mathematics influenced by Chinese disappeared from the history of Korean mathematics, as the school system was hanged into the Western style and the Western mathematics was adopted as the only mathematics to be taught at the Schools of various levels. Thus the 'Enlightenment Period' is the period in which Korean mathematics shifted from Chinese into European.

• Journal of Korean Society of Forest Science
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• v.105 no.4
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• pp.401-413
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• 2016

Forest resources utilization and variable disturbance history have been affected the rarity and conservation value of forest relict trees, which served as habitat for forest biodiversity, important carbon stock and cultural role include human and natural history in South Korea. This study was conducted to establish the baseline data for forest resources conservation by clarifying species diversity, spatial distribution and ecological characteristics (individual and habitat) of forest relict trees (DBH > 300 cm) based on the data getting from mountain trail, high resolution aerial photos and field professionals and field survey. As results, 54 taxa (18 family 32 genus 48 species 1 subspecies 3 variety and 2 form) as about 22% of tree species in Korea was identified in the field. 837 individuals of forest relict trees were observed and the majority of the trees was in Pinaceae, deciduous Fagaceae and Rosaceae, which families are abundant in population diversity. High elevation area was important to relict trees as mean altitudinal distribution was 1,200 m a.s.l as likely affected by human activity gradients and mid-steep slope and North aspect was important environment for the trees remain. Many individuals exhibited 'damage larger branch' (55.6%) and consequent relatively lower mean canopy coverages (below 80%). Synthetically, present diversity and abundance of relict forest trees in South Korea were the result of complex process among climate variation, local weather and biological factors and the trees of big and old were estimated to important forest biodiversity elements. In the future, clarifying the role and function of relict trees in forest ecosystem, in- and ex- situ programmes for important trees and habitat, and activities for building the background of conservation policy such as "Guideline for identifying and measurement of forest relict trees".

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.397-402
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• 2013

The pharmacological efficacy of Protaetia (P.) brevitarsis larvae has been described in the Dongui Bogam. It is believed that the larvae are particularly useful for hepatic disorders. However, natural aversion has made it difficult to consume these larvae as food. Thus, we sought to make an eatable form of the larvae by establishing optimal conditions for larvae preparation. Larvae were selectively bred, sterilized, and a powder of larvae generated by freeze-drying. Afterward, the CellTiter $96^{(R)}$ AQueous Non-Radioactive Cell Proliferation Assay (MTS) with the RAW 264.7 cell line was used to validate the safety of the powder as a food ingredient. We determined that oak sawdust sterilized by water vapor for 5 minutes could be used for larvae feed, and a feeding for 3~5 days followed by a fasting for 3 days were optimal conditions for larvae preparation. In addition, sterilization of larvae at $115^{\circ}C$ and $0.9kgf/cm^3$ (to avoid contamination of pathogenic bacteria and fungi) was successfully applied in the production of edible powder from P. brevitarsis. The optimized processes established in our experiments can be used in the industrial production of P. brevitarsis as a food ingredient.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.2
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• pp.41-51
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• 2013

The tidal creek dependent mass transport characteristic in Gyeong-Gi Bay (west coast of Korea) was studied using field measured data and numerical model. Gyeong-Gi Bay consists of 3 main tidal channels and contains a well-developed vast tidal flat. This region is famous for its large tidal difference and strong current. We aim to study the effect of tidal creek in the tidal flat on the mass exchange between the estuary and the ocean. For numerical application, the application of unstructured grid feature is essential, since the tidal creek has complicated shape and form. For this purpose, the FVCOM is applied to the study area and simulation is performed for 2 different cases. In case A, geographic characteristics of the tidal creek is ignored in the numerical grid and in case B, the tidal creek are constructed using unstructured grid. And these 2 cases are compared with the field measured cross-channel mass transport data. The cross-channel mass transport at the Yeomha waterway mouth and Incheon harbor was measured in June, 9~10 (Spring tide) and 17~18 (Neap tide), 2009. CTD casting and ADCP cross-channel transect was conducted 13 times in one tidal cycle. The observation data analysis results showed that mass transport has characteristic of the ebb dominance Line 1 (Yeomha waterway mouth), on the other hand, a flood dominant characteristic is shown in Line 2 (Incheon harbor front). By comparing the numerical model (case A & B) with observation data, we found that the case B results show much better agreement with measurement data than case A. It is showed that the geographic feature of tidal creek should be considered in grid design of numerical model in order to understand the mass transport characteristics over large tidal flat area.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1284-1289
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• 2007

The Biological Activated Carbon (BAC) process in the water treatments represents a kind of biofiltration process which capabilities of bacteria to remove organic matters are maximized. It enables to eliminate organic matters and effectively reduce microbial regrowth potentials. As attached bacteria employ natural organic matter as a substrate, they are significantly dependent on indigenous microorganisms. In this study, characteristics of bacterial community by culturable and unculturable Methods have been conducted in a pilot plant using SAC in water treatment process at the downstream of the Nakdong River. Based on the results, HPC and bacterial- production for coal-based activated carbon material were $1.20{\sim}56.2{\times}l0^7$ cfu/g and $1.2{\sim}3.7\;mgC/m^{3}h$, respectively, in the SAC process. The highest level of attached bacteria biomass and organic carbon removal efficiency was found in the coal-based activated carbon. The genera Pseudomonas, Flavobacterium, Alcaligenes, Acilzetobacter, and Spingomonas were identified for each activated carbon material. Pseudomonas vesicularis was the dominant species in the coconut- and coal-based materials, where as Pseudomonas cepacia was the dominant species in the wood-based material. The Scanning Electron Microscope (SEM) observation of the activated carbon surface also found the widespread distribution of rod form and coccus. The community of attached bacteria was investigated by performing Fluorescent in situ hybridization (FISH) analysis. a group was dominant in coal, wood and coccunt-based materials, ${\alpha},\;{\beta}\;and\;{\gamma}$ group ranged from 27.0 ${\sim}$ 43.0%, 7.1 ${\sim}$ 22.0%, 11.3 ${\sim}$ 28.6%, respectively. These results suggest that a group bacterial community appears to be regulated removal efficiency of organic material in water treatment process.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.3
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• pp.10-25
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• 2011

Since 1950, the city of Yokohama has been demanding the return of US. military base sites in Yokohama. Yokohama has established a systematic utilization plan for these relocation sites. The Fukaya communication site is one of former US. military bases verified for return in 2004. The Fukaya communication site is distinctively circular in shape and is entirely national land. Yokohama took an idea competition to its citizens to create a new park at the relocation of the Fukaya communication site, involving lots of citizen opinion in its utilization goals. This study determined the process of the idea competition at the Fukaya communication site in encouraging civic participation and analyzing citizen demands for the utilization of the relocation site. Through the idea competition, Yokohama city was able to obtain several ideas on the new park from various angles such as the function and shape of the urban open spaces. Citizens showed great interest in creating a park as green infrastructure on the Fukaya communication site. In addition, beyond utilization as an urban open space, many ideas suggested new lifestyles for the region in connection with the natural environment in the vicinity. Yokohama city tried to share the process and results of the idea competition with as many citizens as it could through a variety of means such as Participation, Judging, Support, Observation and Understanding. The case study on the idea competition at the Fukaya communication site is a good example of community design practice in public projects, and is full of suggestions for military bases in Korea, which has just established the plan of utilizing relocation sites as parks. Based on this case study, it can be concluded that it is important to make a systemic form for utilization planning with a clear process, open information and partnership in a variety of participatory design processes in order to ensure maximum civic utilization of relocation sites.

• The Journal of Art Theory & Practice
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• no.1
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• pp.109-144
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• 2003

Orientalness is a concept that expresses the collective identity of the Orient in relation to the West. The concept itself is mutable and defined by the relationship between the two regions at different points in time. Changes in the concept depend on a number of factors, such as cultural influence, the political balance of power between the two regions, and on the interpretative scheme that defines the relationship. In addition, the geographical notion of the concept evolves culturally, socially and politically. During this process, Oriental-ness becomes Oriental-ism at times. I will attempt to survey and measure the progression of Orientalness from its emergence in early 17th century to its subsequent transformation in modern Korea as reflected in art theory and art works. The recognition of the comparative characteristics of Oriental art began when the Orient was exposed to the art of the West in the late Ming dynasty during the early 17th century. The changes in the artistic climate in China affected the late Chosun. I will start with a brief introduction of this time and the birth of Orientalness. The concept gradually changed during the period of Enlightenment(開化期) towards the end of the 19th century, and during the colonial period( 1910-1945) it took on a new form. Establishment of the concept of "Orient"as a single, unifying concept spanning across cultures and national boundaries has been attributed to late Meiji period Japan, whose intention at that time is believed to have been to build a pan-Asia(亞細亞) empire with Japan at its commanding center. It has been stressed that the real motive behind the formation of one single cultural unit, where the shared common written language was Chinese and Confucianism and Taoism were the common metaphysical traditions, was to build one political unit. When the notion of a geographical unit of Asia was replaced by the concept of Asia as a cultural and political unit, a massive growth of interest and discourse were provoked around the concept of Orientalism. When Orientalism was being formulated, Korea automatically became member of "one Asia" when the country became colonized. For Koreans, the identity of the Orient had to be defined in cultural terms, as the political notion of a nation was non-existent at that time. The definition of identity was pursued at two levels, pan-Asian and local. If Orientalism was an elite discourse centered in pan-Asian philosophical and religious tradition, localized Orientalism was a popular discourse emphasizing locality as the byproduct of natural geographic condition. After the liberation in 1945 from colonial rule, a thrust of movement arose towards political nationalism. Two types of discourses on Orientalism, elite and popular, continued as central themes in art. Despite the effort to redefine the national identity by eradicating the cultural language of the colonial past, the past was enduring well into the present time. As discussed above, even when the painting themes were selected from Korean history, the tradition of using history painting as a manifestation of political policy to glorify the local identity had its founding during the Meiji period. The elevation of folk art to the level of high art also goes back to the colonial promotion of local color and local sentiment. Again, the succession of the past (colonial) ideal was defended as the tradition assumed a distinct modern shape that was abstract in style. The concept of the "Orient" is of relative and changing nature. It was formulated in relation to Western culture or civilization. Whatever the real motive of the adoption of them had been, the superiority of the Orient was emphasized at all times. The essence of the Orient was always perceived as the metaphysical tradition as a way to downgrade Western culture as materialistic. This view still prevails and the principle of Orient was always sought in Confucianism, Taoism, and Buddhism. Even when Orientalism was employed by imperialist Japan in an effort to establish her position as the center of the Orient, the spiritual source was still in Chinese philosophy and religion. In art also, the Chinese literati tradition became the major platform for elite discourse. Orientalism was also defined locally, and the so-called local color was pursued in terms of theme and style. Thus trend continued despite the effort to eradicate the remnants of colonial culture long after liberation. These efforts are now being supported politically and also institutionalized to become the aesthetic ideal of the modern Korean art.

• Journal of Intelligence and Information Systems
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• v.20 no.4
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• pp.121-139
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• 2014

Predicting corporate failure has been an important topic in accounting and finance. The costs associated with bankruptcy are high, so the accuracy of bankruptcy prediction is greatly important for financial institutions. Lots of researchers have dealt with the topic associated with bankruptcy prediction in the past three decades. The current research attempts to use ensemble models for improving the performance of bankruptcy prediction. Ensemble classification is to combine individually trained classifiers in order to gain more accurate prediction than individual models. Ensemble techniques are shown to be very useful for improving the generalization ability of the classifier. Bagging is the most commonly used methods for constructing ensemble classifiers. In bagging, the different training data subsets are randomly drawn with replacement from the original training dataset. Base classifiers are trained on the different bootstrap samples. Instance selection is to select critical instances while deleting and removing irrelevant and harmful instances from the original set. Instance selection and bagging are quite well known in data mining. However, few studies have dealt with the integration of instance selection and bagging. This study proposes an improved bagging ensemble based on instance selection using genetic algorithms (GA) for improving the performance of SVM. GA is an efficient optimization procedure based on the theory of natural selection and evolution. GA uses the idea of survival of the fittest by progressively accepting better solutions to the problems. GA searches by maintaining a population of solutions from which better solutions are created rather than making incremental changes to a single solution to the problem. The initial solution population is generated randomly and evolves into the next generation by genetic operators such as selection, crossover and mutation. The solutions coded by strings are evaluated by the fitness function. The proposed model consists of two phases: GA based Instance Selection and Instance based Bagging. In the first phase, GA is used to select optimal instance subset that is used as input data of bagging model. In this study, the chromosome is encoded as a form of binary string for the instance subset. In this phase, the population size was set to 100 while maximum number of generations was set to 150. We set the crossover rate and mutation rate to 0.7 and 0.1 respectively. We used the prediction accuracy of model as the fitness function of GA. SVM model is trained on training data set using the selected instance subset. The prediction accuracy of SVM model over test data set is used as fitness value in order to avoid overfitting. In the second phase, we used the optimal instance subset selected in the first phase as input data of bagging model. We used SVM model as base classifier for bagging ensemble. The majority voting scheme was used as a combining method in this study. This study applies the proposed model to the bankruptcy prediction problem using a real data set from Korean companies. The research data used in this study contains 1832 externally non-audited firms which filed for bankruptcy (916 cases) and non-bankruptcy (916 cases). Financial ratios categorized as stability, profitability, growth, activity and cash flow were investigated through literature review and basic statistical methods and we selected 8 financial ratios as the final input variables. We separated the whole data into three subsets as training, test and validation data set. In this study, we compared the proposed model with several comparative models including the simple individual SVM model, the simple bagging model and the instance selection based SVM model. The McNemar tests were used to examine whether the proposed model significantly outperforms the other models. The experimental results show that the proposed model outperforms the other models.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.820-825
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• 2007

Earthworm casting was the natural fertilizer that contained high concentrations of nutrients such as nitrogen, phosphate and potassium and of over $10^8$ CFU/ml of microorganisms. Greater than 80% of feed was excreted through the fermentation by the intestinal enzyme, after worm had eaten feeds such as fallen leaves and rotten roots under the ground. Also, the soil structure of casting was known to be very efficient in the aspects of the porosity, the water permeability, and deodorizing activities. In this research, the biofilter packed with a biomedia made of casting and waste polyurethane foam, a binder, which helped to improve the durability and perpetuity of casting, was investigated to degrade malodorous hydrogen sulfide gas. The biomedia had no need of extra supply of nutrients and of microbial inoculations. On the beginning of the operations, it showed 100% removal of hydrogen sulfide gas without lag phase. At SV of 50 $h^{-1}$, hydrogen sulfide gas from the outlet of the biofilter was not detected, when inlet concentration increased to 450 ppmv. After that, removal efficiency decreased as increasing inlet hydrogen sulfide concentration. Hydrogen sulfide removal was maintained at almost 93% until inlet concentration was increased up to 950 ppmv, at which the elimination capacity of $H_2S$ was 61.2 g $S{\cdot}m^{-3}{\cdot}h^{-1}$. Maximum elimination capacity guaranteing 90% removal was 61.2, 65.9, 84.7, 89.4 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV ranging from 50 $h^{-1}$ to 300 $h^{-1}$, but was 59.3 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV of 400 $h^{-1}$. The results calculated from Michaelis-Menten equation revealed that $V_m$ increased from 66.04, 88.96, 117.35, 224.15, to 227.54 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ with increasing space velocity in the range of 50 $h^{-1}$ to 400 $h^{-1}$. However, saturation constant$(K_s)$ decreased from 79.97 ppmv to 64.95 and 65.37 ppmv, and then increased to 127.72 and 157.43 ppmv.

• Journal for History of Mathematics
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• v.2 no.1
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• pp.91-105
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• 1985

Though the tradition of Korean mathematics since the ancient time up to the "Enlightenment Period" in the late 19th century had been under the influence of the Chinese mathematics, it strove to develop its own independent of Chinese. However, the fact that it couldn't succeed to form the independent Korean mathematics in spite of many chances under the reign of Kings Sejong, Youngjo, and Joungjo was mainly due to the use of Chinese characters by Koreans. Han-gul (Korean characters) invented by King Sejong had not been used widely as it was called and despised Un-mun and Koreans still used Chinese characters as the only "true letters" (Jin-suh). The correlation between characters and culture was such that , if Koreans used Han-gul as their official letters, we may have different picture of Korean mathematics. It is quite interesting to note that the mathematics in the "Enlightenment Period" changed rather smoothly into the Western mathematics at the time when Han-gul was used officially with Chinese characters. In Koryo, the mathematics existed only as a part of the Confucian refinement, not as the object of sincere study. The mathematics in Koryo inherited that of the Unified Shilla without any remarkable development of its own, and the mathematicians were the Inner Officials isolated from the outside world who maintained their positions as specialists amid the turbulence of political changes. They formed a kind of Guild, their posts becoming patrimony. The mathematics in Koryo is significant in that they paved the way for that of Chosun through a few books of mathematics such as "Sanhak-Kyemong, "Yanghwi - Sanpup" and "Sangmyung-Sanpup." King Sejong was quite phenomenal in his policy of promotion of mathematics. King himself was deeply interested in the study, createing an atmosphere in which all the high ranking officials and scholars highly valued mathematics. The sudden development of mathematic culture was mainly due to the personality and capacity of King who took any one with the mathematic talent onto government service regardless of his birth and against the strong opposition of the conservative officials. However, King's view of mathematics never resulted in the true development of mathematics per se and he used it only as an official technique in the tradition way. Korean mathematics in King Sejong's reign was based upon both the natural philosophy in China and the unique geo-political reality of Korean peninsula. The reason why the mathematic culture failed to develop continually against those social background was that the mathematicians were not allowed to play the vital role in that culture, they being only the instrument for the personality or politics of the King. While the learned scholar class sometimes played the important role for the development of the mathematic culture, they often as not became an adamant barrier to it. As the society in Chosun needed the function of mathematics acutely, the mathematicians formed the settled class called Jung-in (Middle-Man). Jung-in was a unique class in Chosun and we can't find its equivalent in China of Japan. These Jung-in mathematician officials lacked tendency to publish their study, since their society was strictly exclusive and their knowledge was very limited. Though they were relatively low class, these mathematicians played very important role in Chosun society. In "Sil-Hak (the Practical Learning) period" which began in the late 16th century, especially in the reigns of King Youngjo and Jungjo, which was called the Renaissance of Chosun, the ambitious policy for the development of science and technology called for the rapid increase of the number of such technocrats as mathematicians inevitably became quite ambitious and proud. They tried to explore deeply into mathematics per se beyond the narrow limit of knowledge required for their office. Thus, in this period the mathematics developed rapidly, undergoing very important changes. The characteristic features of the mathematics in this period were: Jung-in mathematicians' active study an publication, the mathematic studies by the renowned scholars of Sil-Hak, joint works by these two classes, their approach to the Western mathematics and their effort to develop Korean mathematics. Toward the "Enlightenment Period" in the late 19th century, the Western mathematics experienced great difficulty to take its roots in the Peninsula which had been under the strong influence of Confucian ideology and traditional Korean mathematic system. However, with King Kojong's ordinance in 1895, the traditonal Korean mathematics influenced by Chinese disappeared from the history of Korean mathematics, as the school system was changed into the Western style and the Western matehmatics was adopted as the only mathematics to be taught at the schools of various levels. Thus the "Enlightenment Period" is the period in which Korean mathematics sifted from Chinese into European.od" is the period in which Korean mathematics sifted from Chinese into European.pean.