• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.327-335
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• 1999

A batch process in which transfer bars are rolled in single bar units involves many problems in terms of quality, yield and threading stability. The endless rolling process is an effective solution to such problems. In this, study, an analysis model is proposed to calculate the distribution of normal stress in endless rolling process. The model was examined by comparing with the result of experiment. A device using the spring is developed for improving the welding quality.

• 대한산업공학회지
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• 제27권2호
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• pp.135-139
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• 2001

A process control procedure is suggested when screening inspection is performed with a surrogate variable correlated with the performance variable. Assuming bivariate normal distribution for the performance and screening variable, the procedure is designed on the basis of the time required for detecting process shift.

• 품질경영학회지
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• 제27권1호
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• pp.18-34
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• 1999

This paper is a brief review of the different procedures that are available for fitting theoretical distributions to data. The use of each technique Is illustrated by reference to a distribution system which including the Pearson, Johnson and Burr functions. These functions can be used to calculate percent out of specification. Therefore, in this paper a new method for estimating a measure of process capability for Gamma distributed variable data proposed using the percentage nonconforming. Process capability indices combines with the percentage nonconforming Information can be used to evaluate more accurately process capability.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 1999년도 춘계공동학술대회:정보화시대의 지식경영
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• pp.46-46
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• 1999

• Kyungpook Mathematical Journal
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• 제18권2호
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• pp.189-193
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• 1978

• 한국수산과학회지
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• 제12권3호
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• pp.167-173
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• 1979

생물학적 고정막(biological fixed-film)을 이용한 REMSMAS공법이 개발되었다. REMSMAS 공법에서 유기물질 제거속도에 관한 수학적 model는 CMAS공법과는 많은 차이점이 있었으며, 유기물질 제거속도에 대한 동력학적 해석은 screen media에 부착된 활성미생물과 부유상태의 미생물에 근거를 두어 해석하였다. 단일폭기 CMAS공법은 steady-strate에 도달된 후 연속적으로 공칭체류시간이 4.5, 6, 9.5 및 12시간으로 운전되었고 REMSMAS 공법은 공칭체류시간이 6시간 및 12시간으로 운전되었으며 운전초기는 nonsteady-state상태였다. 또한 시수는 원액을 약 18배 희석하여 COD값이 950mg/l, BOD값이 450mg/l 되도록 하였다. 부유상태의 미생물에 근거를 둔 설계인자들은 단일폭기 CMAS공법 의하여 구하여 졌으며 이 값들은 REMSMAS공법의 유기물 제거속도에 대한 동력학적 상수를 구하는 이용되었다. 단일폭기 CMAS공법에서 얻어진 $Y_2,\;K_d,(\mu_{max})_s\;and\;K_s$ 및 $K_s$값은 각각 0.78, 0.27/hr, 1.1/hr, 95mg/l였다. REMSMAS공법에서 단위표면적당 유기물 부하량상수 값은 $9.1mg/cm^2-day$였고 포화상수(Kg)값은 평균 53.5mg/l였다. REMSMAS공법은 steady-state 운전될 때는 유기물 제거율은 단일폭기 CMAS법 보다 높게 나타났으나 한계운전 기일에 도달됨에 따라 감소 한다.

• Applied Microscopy
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• 제29권3호
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• pp.315-321
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• 1999

12주령 랫트의 정상 비골골절의 치유과정을 이해하고, 난소적출 후 비골골절의 치유과정과 난소적출 후 비골골절의 치유에 미치는 $1\alpha$, 25 dihyoxycholecalciferol의 영향을 알아보고자 실험을 실시한 결과 다음과 같은 결론을 얻었다. 비골의 골절은 골절유발 후 5주에 성숙된 신생골 조직으로 충만되어 조직형태학적으로 완전한 치유가 이루어졌다. 난소적출 후 골절의 치유는 정상골절의 치유보다 지연되었으나, $1\alpha$, 25 dihydroxycholecalciferol 투여 결과 골절유발 후 5주에 성숙된 신생골 조직으로 골절단이 충만되어 정상상태의 골절과 비슷하게 치유가 되었다. 이상의 결과를 종합해보면 랫트의 난소를 적출하여 여성호르몬의 결핍을 유발하면 난소적출 후 7주에는 골다공증이 발생되고, 골다공증은 정상상태의 골절에 비하여 약 1주일 이상 골절의 치유를 지연시켰으며, $1\alpha$, 25 dihydroxycholecalciferol을 투여하였을 경우 정상상태의 골절치유와 비슷한 경과를 나타내어 $1\alpha$, 25 dihydroxycholecalciferol은 골다공증성 골절의 치료에 있어서 효과있는 치료제라는 결론을 내릴 수 있었다.

• 동의생리병리학회지
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• 제33권5호
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• pp.249-254
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• 2019

This study is aimed to refute against medical opponent's claim that Korean medicine does not conform to the conditions of science. Analyses and refutations against a journal treatise and a Facebook column formally written for a logical criticism and attack were conducted. As an example of the logic of the knowledge production process in Chinese medicine, 8 principle theory was exemplified in the Han danasty Classics "Neijing" and "Shanghanlun" at first. The knowledge was continuously revised and accumulated historically and then completed through Ming、Cheng period. The differential diagnosis and treatment theory is a logical process of forming knowledge through the process of abduction, deduction and induction begun from "Shanghanlun" succeeded to nowadays and it is essentially equaled with the process of experimental inference by Claude Bernard. Examples of normal science status based on Kuhn's scientific standards include the theory of 8 principle, differntial diagnosis of viscera and bowel, 3 yang and 3 yin diseases of "Shanghanlun" and warm disease theory. Examples of science lost or get its normal status by refutation following Popper's standards were cold damage theory and warm disease theory respectively. This allowed Chinese medicine to follow the general principles of science that form scientific knowledge and to correspond with the demarcation standards and concepts of science. However, as one of the conditions for becoming a science, Chinese medicine is partially lacking in terms of the interpretation of text language or the accordance with modern knowledge. Therefore methods are required to supplement this lack through multi-faceted research such as literature-based, theoretical and clinical studies.

• 한국지열·수열에너지학회논문집
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• 제18권4호
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• pp.12-21
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• 2022

Steam assisted gravity drainage(SAGD) is a process that drills well in the underground oil sands layer, injects hightemperature steam, lowers the viscosity of buried bitumen, and recovers it to the ground. Recently, direct contact steam generator(DCSG) is being developed to maximize steam efficiency for SAGD process. The DCSG requires high technology to achieve pressurized combustion and steam generation in accordance with underground pressurized conditions. Therefore, it is necessary to develop a combustion technology that can control the heat load and exhaust gas composition. In this study, process analysis of high-pressurized DCSG was conducted to apply oxygen enrichment technology in which nitrogen of the air was partially removed for increasing steam production and reducing fuel consumption. As the process analysis conditions, methane as the fuel and normal air or oxygen enriched air as the oxidizing agent were applied to high-pressurized DCSG process model. A simple combustion reaction program was used to calculate the property variations for combustion temperature, steam ratio and residual heat in exhaust gas. As a major results, the steam production efficiency of DCSG using the pure oxygen was about 6% higher than that of the normal air due to the reducing nitrogen in the air. The results of this study will be used as operating data to test the demonstration device.

• 환경위생공학
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• 제23권4호
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• pp.73-82
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• 2008

In this study, a dry single-phase anaerobic digestion process (Dranco system) was investigated to evaluate the optimum operational conditions. Several factors such as injection rate of organic waste, biogas production, $CH_4$ content in the biogas, pH of the sludge, $NH_3$-N and VFA concentration were investigated based on the operation of the digestion process for 2 months (short term) and 8 months (long-term). The operation results showed that a small quantity of food waste should be injected every week and that a 10% increase of the microorganism injection rate should be needed. However, normal operation was conducted after 11 weeks based on the designed quantity. The $CH_4$ content in the biogas was high at the beginning and the end of the food injection. However, it was low during week days. When the biogas production was high, the $CH_4$ concentration was low. The biogas production increased with an increase of the injection rate. $100m^3$/ton of biogas was produced from normal operation of the digestion process based on the designed quantity. The pH values of the digestion tank based on short-term operation ranged from 8 to 8.5. However, the pH values ranged from 7.45 to 8.15 after 4 weeks of long-term operation. The $NH_3$-N concentration of short-term operation ranged from 4,500 to 5,500 ppm and it gradually decreased to 2,000ppm after normal operation was commenced. For long-term operation, it was 5,000ppm initially and 3,800ppm after normal operation was commenced. The VFA concentration of sludge was less than 900ppm and 2,500ppm for short and long-term operations, respectively, after normal operation. Overall, the differences between sludge pH, $NH_3$-N and VFA concentrations may be due to the different types of microorganisms and the digestion ability of the microorganisms which exist in the accumulation of non digested organics. Moreover, it may be also caused by the type of food waste. Further investigation is needed to confirm these relationships.