• 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.

• Clinical and Experimental Pediatrics
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• v.48 no.6
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• pp.588-593
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• 2005

Purpose : Obesity is associated with disturbances of ventilatory functions in adults. But few studies have evaluated the pulmonary complications of obesity in the pediatric population. The purpose of this study is to clarify the effects of obesity on pulmonary function and body composition in obese children. Methods : Forty seven obese children whose ages ranged from nine to twelve years were evaluated for their body composition(intracellular fluid, extracellular fluid, protein mass, mineral mass, soft lean mass, fat mass, percent body fat, fat distribution) by bioelectrical impedance analysis. Hemoglobin, serum glucose, aspartate aminotransferase(AST), alanine aminotransferase(ALT), total cholesterol and triglycerides were measured. Pulmonary function test was performed by spirometer. Results : Intracellular fluid, protein mass, fat mass, percent body fat and fat distribution were significantly higher in severely obese children with an obesity index of more than 150 percent compared with those with an index of less than 150 percent. Peak expiratory flow rate(PEFR) was significantly lower in severely obese children with obesity index of more than 150 percent compared with those with less than 150 percent($241.7{\pm}14.6L/sec$ vs $276.8{\pm}64.3L/sec$). PEFR, forced expiratory flow 25 percent($FEF_{25}$), mid expiratory flow rate(MEFR), forced expiratory flow 50 percent($FEF_{50}$), forced expiratory volume in 1st second($FEV_1$) and forced vital capacity(FVC) were decreased in 37.0 percent, 14.8 percent, 14.8 percent, 11.1 percent, 3.7 percent and 3.7 percent of obese children, respectively. Conclusion : PEFR was significantly decreased in obese children. Pulmonary function test must be performed in severely obese children and more extended study is needed in other age groups.

• Journal of Gastric Cancer
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• v.8 no.1
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• pp.35-39
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• 2008

Purpose: This study was aimed to evaluate the efficacy and safety of of intravenous iron sucrose ($Venoferrum^{(R)}$) for treating the perioperative anemic gastrectomy patients. Materials and Methods: From September 2006 to February 2007 at Seoul National University Hospital, the gastrectomy patients who displayed perioperative anemia (7.0 g/dl $\leq$ hemoglobin levels (Hb) < 11.0 g/dl) and who were admitted or visited the outpatient clinic of the Department of surgery, were divided into two groups. The preoperative (${\leq}\;2{\sim}3$ weeks before gastrectomy) or postoperative ($\geq$ 1 month after gastrectomy) patients without evidence of acute bleeding were included into Group 1. The immediate postoperative (< 1 month after gastrectomy) patients with stable vital signs were included into Group 2. The age, gender, diagnosis, Hb, hematocrit (Hct), mean corpuscular volume (MCV), serum ferritin (SF), total iron binding capacity (TIBC), serum iron and reticulocyte counts (RC) were evaluated before and after intravenous iron sucrose administration. The adverse effects of drugs were investigated. Results: The number of patients of group 1 and group 2 was 79 and 46, respectively. In group 1, there was a statistically significant difference in the Hb, Hct, MCV, SF, RC and TIBC with each mean change of 1.3 g/dl, 4.1%, 3.1ft, 195 ng/ml, 0.2% and -86.4 ug/dl, respectively. In group 2, there was a statistically significant difference in the Hb, Hct, MCV, SF and RC with each mean change of 1.8 g/dl, 6.1%, 3.4fl, 260 ng/ml and 0.3%, respectively. Two patients (1.6%) suffered local thrombophlebitis as an adverse effect. Conclusion: Intravenous iron sucrose for the perioperative anemia of gastrectomy patients was efficacious in the short period without significant adverse effects.

• Tuberculosis and Respiratory Diseases
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• v.71 no.5
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• pp.328-334
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• 2011

Background: Chronic obstructive pulmonary disease (COPD) is a major cause of chronic morbidity and mortality throughout the world and is the only major disease that is continuing to increase in both prevalence and mortality. The second Korean National Health and Nutrition Survey revealed that the prevalence of COPD in Korean subjects aged ${\geq}45$ years was 17.2% in 2001. Further surveys on the prevalence of COPD were not available until 2007. Here, we report the prevalence of spirometrically detected COPD in Korea, using data from the fourth Korean National Health and Nutrition Survey (KNHANES IV) which was conducted in 2007~2009. Methods: Based on the Korean Statistical Office census that used nationwide stratified random sampling, 10,523 subjects aged ${\geq}40$ years underwent spirometry. Place of residence, levels of education, income, and smoking status, as well as other results from a COPD survey questionnaire were also assessed. Results: The prevalence of COPD (defined as forced expiratory volume in 1 sec/forced vital capacity <0.7 in subjects aged ${\geq}40$ years) was 12.9% (men, 18.7%; women, 7.5%). In total, 96.5% of patients with COPD had mild-to-moderate disease; only 2.5% had been diagnosed by physicians, and only 1.7% had been treated. The independent risk factors for COPD were smoking, advanced age, and male gender. Conclusion: The prevalence of COPD was 12.9% in the KNHANES IV data. Most patients with COPD were undiagnosed and untreated. Based on these results, a strategy for early COPD intervention is warranted in high risk subjects.

• Journal of the Korean Institute of Navigation
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• v.13 no.1
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• pp.21-53
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• 1989

In the past twenty years, there has been a rapid increase in the volume of traffic in Korea due to the Korean great growth of the Korean economy. Since transformation provides an infrastructure vital to economic growth, it becomes more and more an integral part of the Korea economy. The importance of coastal shipping stands out in particular, not only because of the expansion limit on the road network, but also because of saturation in the capacity of rail transportation. In spite of this increase and its importance, coastal shipping is falling behind partly because it is givenless emphasis than ocean-going shipping and other inland transportation systems and partly because of overcompetition due to excessive ship tonnage. Therefore, estimating and planning optimum ship tonnage is the first take to develop Korean coastal shipping. This paper aims to estimate the optimum coastal ship tonnage by computer simulation and finally to draw up plans for the ship tonnage balance according to supply and demand. The estimation of the optimum ship tonnage is peformed by the method of Origin -Destimation and time series analysis. The result are as follows : (1) The optimum ship tonnage in 1987 was 358, 680 DWT, which is 54% of the current ship tonnage (481 ships, 662, 664DWT) that is equal to the optimum ship tonnage in 1998. this overcapacity result is in excessive competition and financial difficulties in Korea coastal shipping. (2) The excessive ship tonnage can be broken down into ship types as follows : oil carrier 250, 926 DWT(350%), cement carrier 9, 977 DWT(119%), iron material/machinery carrier 25, 665 DWT(117%), general cargo carrier 17, 416DWT(112%). (3) the current total ship crew of 5, 079 is more than the verified optimally efficient figure of 3, 808 by 1271. (4) From the viewpoint of management strategy, it is necessary that excessive ship tonnage be reduced and uneconomic outdated vessels be broken up. And its found that the diversion into economically efficient fleets is urgently required in order to meet increasing annual rate in the amounts of cargo(23, 877DWT). (5) The plans for the ship tonnage balance according to supply and demand are as follows 1) The establishment of a legislative system for the arrangement of ship tonnage. This would involve; (a) The announcement of an optimum tonnage which guides the licensing of cargo vessels and ship tonnage supply. (b) The establishment of an organization that substantially arrangement tonnage in Korea coastal shipping. 2) The announcement of an optimum ship tonnage both per year and short-term that guides current tonnage supply plans. 3) The settlement of elastic tariffs resulting in the protect6ion of coastal shipping's share from other tonnage supply plans. 4) The settlement of elastic tariffs resulting in the protection of coastal shipping's share from other transportation systems. 4) Restriction of ocean-going vessels from participating in coastal shipping routes. 5) Business rationalization of coastal shipping company which reduces uneconomic outdated vessels and boosts the national economy. If we are to achieve these ends, the followings are prerequisites; I) Because many non-licensed vessels are actually operating and threatening the safe voyage of the others in Korea coastal routes, it is necessary that those ind of vessels be controlled and punished by the authorities. II) The supply of ship tonnage in Korean coastal routes should be predently monitored because most of the coastal vessels are to small to be diverted into ocean-going routes in case of excessive supply. III) Every ship type which is engaged in coastal shipping should be specialized according to the characteristics of its routes as soon possible.

• Journal of Preventive Medicine and Public Health
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• v.24 no.1 s.33
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• pp.37-44
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• 1991

In the plywood manufacturing factory established in 1979, female 3 workers who had exposed to adhesives containing formaldehyde for more than 48 months of duration suffered from eye, nasal, oral, throat and skin irritation and dyspnea as chief complaints. The actual level of the exposure to formaldehyde were not estimated when the exposed workers started to have above symptoms. The environmental monitoring of workplace was measured on April 25, 1990, and the concentration of formaldehyde revealed 0.2 ppm, however the exhaustive ventilatory system was already installed at that time. Twenty six subjects from entire factory were examined by questionnaire, physical examination and spirometry, etc. on August 22, 1990. Significant difference was observed in symptoms and signs of nasal, oral and throat irritation between the exposed group with longer duration and that with short duration. When the exposed group with longer duration was compared to the group of nonexposed, symptoms and signs of nasal, oral, throat and skin irritaion, chest tightness and dullness were significantly increased in the former group. The results of the spirometric test showed that the forced vital capacity and the forced expiratory volume at 1 second were decreased among the exposed group with longer duration but not significant.

• Journal of Preventive Medicine and Public Health
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• v.28 no.1 s.49
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• pp.43-57
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• 1995

In order to study the effect of welding fume exposure upon the pulmonary function test, we examined 131 shielded arc welding workers, and 152 $CO_2$ arc welding workers as cases and 177 control workers for their general characteristics, and forced vital capacity (FVC), forced expiratory volume in one second $(FEV_{1.0})$, forced expiratory volume in one second as a percent of FVC $(FEV_{1.0}%)$, and maximal mid-expiratory flow (MMF) were obtained from the spirogram. In shielded arc welding group and $CO_2$ arc welding group, FVC, $FEV_{1.0},\;FEV_{1.0}%$, and MMF were significantly decreased than control group, especially marked in the MMF finding. The distribution of workers below normal range was as follows. in the shielded arc welding group, 2 workers(1.5%) for FVC, 17 workers(13.0%) for $FEV_{1.0}$, 5 workers(3.8%) for $FEV_{1.0}%$, 28 workers(21.4%) for MMF, and in the $CO_2$ arc welding group, 3 workers(2.0%) for FVC, 25 workers(16.4%) for $FEV_{1.0}$, 8 workers(5.3%) for $FEV_{1.0}%$, and 37 workers(24.3%) for MMF, and significant increase by exposure duration was found in MMF. The distribution of workers who had ventilation impairment was as follows: 5 workers(3.8%) for obstructive type, 2 workers(1.5%) for restrictive type in the shielded arc welding group, and 7 workers(4.6%) for obstructive type, 2 workers(1.3%) for restrictive type, and 1 worker(0.6%) was combined type of the $CO_2$ arc welding group. In the respect of these results, the significant pulmonary function and ventilatory impairment were observed in welding fume exposed workers who had not abnormal finding in chest X-ray, and MMF considered as the most sensitive pulmonary function index by welding fume exposure. Therefore even if it is hard to doing pulmonary function test in the first health examination of workers according to the Industrial Safety Health Act in the welding fume exposure workers, it is desirable to consider doing PFT. Also evaluating the ventilation impairment, it is necessary, to observe the change of MMF that marker of effort-independent portion.

• Clinical and Experimental Pediatrics
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• v.45 no.5
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• pp.588-595
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• 2002

Purpose : The incidence of obesity has increased in Korea recently. Obesity leads to higher risks of hypertension, hyperlipidemia and insulin resistance. It also leads to risks of respiratory complications. This study was performed to see the effects of obesity on children's pulmonary functions and on developed bronchospasm after exercise loading according to their obesity degrees. Methods : 257 obese children and 150 non-obese children were enrolled. Obese children were divided into 3 groups by the obesity degrees. Pre- and post-exercise loading $FEV_1$(forced expiratory volume at one second), FVC(forced vital capacity) and PEFR(peak expiratory flow rate) were checked in all subjects. The percent predicted values of each parameter was compared according to obesity degrees and the differences between pre-exercise and post-exercise values. Results : The percent predicted value of $FEV_1$, FVC decreased only in the severe obesity group compared with those in the control group. However percent predicted PEFR declined according to obesity degrees. The percent predicted value of $FEV_1$, FVC and PEFR after exercise loading were much lower than those before exercise loading in all groups. Conclusion : As the degree of obesity was higher, the percent predicted value of pulmonary function was lower. And after exercise loading, as the degree of obesity was higher, the reduction of percent predicted value of pulmonary function was larger. Therefore the pulmonary function in obese children must be observed carefully. Further studies on the effects of pulmonary functions in obese children are necessary.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.746-753
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• 1998

Background : Cigarette smoking is closely related to both lung cancer and chronic obstructive pulmonary disease. The incidence of lung cancer is higher in patients with obstructive ventilatory impairment than in patients without obstructive ventilatory impairment regardless of smoking. So, obstructive ventilatory impairment is suspected as an independent risk factor of lung cancer. Methods: For the evaluation of the role of obstructive ventilatory impairment as a risk factor of lung cancer, a total of 73 cases comprising 47 cases of malignant and 26 benign solitary pulmonary nodule were analyzed retrospectively. A comparative study of analysis of forced expiratory volume curves and frequencies of obstructive ventilatory impairment were made between cases with malignant and benign nodules. Results: In comparison of vital capacity and parameters derived from forced expiratory volume curve between two groups. VC, FVC and $FEV_1$ were not significantly different. whereas $FEV_1/FVC%$ and FEF 25-75% showed a significant decrease in the cases with malignant nodule. The frequency of obstructive ventilatory impairment determined by pulmonary function test was significantly higher in the cases with malignant nodule(23.4%) than in benign nodule(3.8%). When the risk for lung cancer was examined by the presence or absence of obstructive ventilatory impairment using the logistic regression analysis, the unadjusted relative risk for the lung cancer of obstructive ventilatory impairment was 17.17. When the effect of smoking and age were considered, the relative risk was to 8.13. Conclusion: These findings suggest that an obstructive ventilatory impairment is a risk factor of lung cancer.

• Tuberculosis and Respiratory Diseases
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• v.47 no.6
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• pp.836-842
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• 1999

Background: Mixed obstructive and restrictive pattern of spirometry can not be concluded in the presence of true restrictive disorders because pure obstructive disorders can also show reduced vital capacity. However, it is not known how many patients with mixed spirometric pattern really have restrictive disorders in Korea whose pattern of pulmonary diseases is somewhat different from foreign countries. To answer this question, I performed this study and tried to answer it according to diseases in addition. Method: Test results from 413 patients who undergone both spirometry and lung volume measurements on the same visit from August 1, 1998 to July 31, 1999 were included. Spirometry data were classified as mixed obstructive-restrictive pattern when spirometry showed '$FEV_1/FVC$<70% (<65% if age$\geq$60)' and FVC<80% of predicted value'. TLC by the method of nitrogen washout was considered as gold standard to diagnose restrictive disorders in which TLC is less than 80% of predicted value. Results: Out of 404 patients who could be evaluated, 58 had mixed pattern of spirometry. 58 patients were suffered from airway diseases(39 patients) such as COPD(22 patients, 38%), asthma(11, 19%), bronchiectasis (6,10%), and sequelae of pulmonary tuberculosis(15, 26%) or other diseases(4,7%). Only 18 out of 58(31%) were confirmed to have true restrictive disorders by TLC. The proportion of true restrictive disorders was different according to diseases, 20.5%(8/39patients) in patients with airway diseases and 53.3%(8/15) with sequelae of pulmonary tuberculosis(p<0.05). Conclusion: Many patients whose spirometry showed mixed pattern didn't have restrictive disorders but had pure obstructive disorders. This was true for more patients with airway diseases. Therefore it would be prudent that lung volume be tested to diagnose restrictive disorders in patients with mixed spirometric pattern.