• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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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.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.2
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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.

• Journal of Korean Society for Quality Management
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• v.27 no.1
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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.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.46-46
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• 1999

• Kyungpook Mathematical Journal
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• v.18 no.2
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• pp.189-193
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• 1978

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.167-173
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• 1979

It is preented the removable moving screen media-activated sludge (REMSMAS) process by using the biological fixed-film systems. The substrate removal kinetic difference between the aeration-only completed mixing activated sludge (CMAS) process and REMSMAS process were observed. The substrate removal kinetics were developed based on the attached and suspended microbial growths. The units of the aeration-only CMAS process were continously operated with the normal detention time of 4.5, 6, 9.5 and 12 flours studies after steady-state condition and the operating of the REMSMAS units conducted with the normal detention time of 6 and 12 hours studies in nonsteady-state condition. The feed solution was diluted 18 times to the raw starch wastewater in of order to maintain the proper COD (950mg/l) and BOD (450mg/l) concentration. Design parameters related to the suspended microbial growths were caculated by the equations used in the aeration-only CMAS model and these parameters used to evalute the kinetic constants in the REMSMAS process. The kinetic constant values of $Y_2,\;K_d,(\mu_{max})_s\;and\;K_s$ from Monod equations were respectively 0.78, 0.027/hr, 1.1/hr and 95mg/l in the aeration-only CMAS process. The value of the aera capacity (F) appeared to be $9.1\;mg/cm^2-day$ and the mean value of the saturation constant $(K_g)$ appeared to be 53.5 mg/l in the REMSMAs process. Also, the substrate removal .ate of the REMSMAS process was higher than that of the normal activated sludge process when this system was operated in steady-state condition. However, the rate was reduced as the critical operating day was approached.

• Applied Microscopy
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• v.29 no.3
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• pp.315-321
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• 1999

Vitamin D is one of important factors involved in the regulation of bone metabolism. In osteoporosis, the therapeutic effect of vitamin D on the healing process of fracture has still been controversial. These studies were designed to understand the healing process of normal fibular fracture and the therapeutic effects of $1\alpha$, 25 dihydroxycholecalciferol on the osteoporotic fracture in rats. The simple transverse fractures of rat fibulae were produced with a rotating diamond saw. The histological and ultrastructural changes of rats were observed. The histological and ultrastructural studies revealed the healing of the fibular fracture in the 5th week after simple transverse fracture. The osteoporosis impaired more the healing of osteoporotic fibular fracture than normal non-osteoporotic fibular fracture. The healing process of osteoporotic fracture was facilitated by the treatment with $1\alpha$, 25 dihydroxycholecalciferol, however, was delayed more than the healing process of normal fracture. These results suggest that $1\alpha$, 25 dihydroxycholecalciferol was effective for reducing the deleterious effects of osteoporosis in fracture healing.

• Journal of Physiology & Pathology in Korean Medicine
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• v.33 no.5
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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.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.18 no.4
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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.

• Journal of environmental and Sanitary engineering
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• v.23 no.4
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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.