• Biomolecules & Therapeutics
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• 제5권1호
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• pp.12-22
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• 1997

Intravenous and oral acute toxicity tests in ICR mice and SD rats and percutaneous acute toxicity tests in SD rats and NZW rabbits were conducted to evaluate the toxicity of DA-5018 and DA-5018 cream, respectively Clinical signs observed in mice and rats after the administration of DA-5018 were similar regardless of administration route. The observed clinical signs were jumping, wild running, lacrimation, ataxia, reddening of extremities and ears, ventral or lateral recumbency, respiratory distress, cyanosis, convulsion and death. Pulmonary enlargement and hemorrhage were observed in the animals died immediately after the dosing of DA-5018. At terminal necropsy, pulmonary enlargement and hemorrhage, corneal opacity and focal scabbing and depilation around nose were seen. LD$_{50}$ Values of DA-5018 are 11.5 mg/kg (mice, male), 12.6 mg/kg (mice, female), 88.3 mg/kg (rat, male) and 73.2 mg/kg (rat, female) in oral toxicity tests and 11.0 mg/kg (mice, male), 18.7 mg/kg (mice, female), 0.12 mg/kg (rat, male) and 0.32 mg/kg (rat, female) in i.v. toxicity tests. In the percutaneous acute toxicity tests of DA-5018 cream, no deaths occured in all the tested groups during 14-day observation period. There were also no abnormalities in the general conditions, body weight changes and on necropsy findings in all groups. LD$_{50}$ values of 0.1 ~0.9% DA-5018 creams in male and female rats and rabbits are >2000 mg/kg./kg.

• 한국응용과학기술학회지
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• 제4권2호
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• pp.7-13
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• 1987

A preliminary investigation was performed to evaluate the possibility of partially replacing palm oil and beef tallow by rapeseed oil for frying oils of instant Ramyon manufacturing. The AOM stability of rapeseed oil was inferior than of palm oil, but was comparable to that of beef tallow. When rapeseed oil was blended with palm oil or beef tallow, the AOM stability of the blended oil was improved. As far as AOM stability is concerned, best results were obtained with a blending ratio of 3 part of rapeseed oil to 7 part of palm oil and a ratio of 4 part of rapeseed oil to 6 part of beef tallow. These blended rapesee oils was retarded the formation of conjugated dienes and polymers during heating. The antioxidative effects on the stabilities of AOM and thermal in blended rapeseed oils showed that TBHQ was superior to tocopherols and a mixture of BHA and BHT was inferior.

• Progress in Superconductivity
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• 제4권2호
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• pp.176-179
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• 2003

A lot of efforts have been focused on the optimization of PIT parameters for Bi-2223/Ag wire. Bi-2223 superconducting wires with 55 filaments were fabricated by stacking, drawing process. Before rolling process, round wires were pre -annealed at 760 - 820 $^{\circ}C$ and low oxygen partial pressure. We confirmed that pre-annealing step was to transform Bi-2212 orthorhombic structure from Bi-2212 tetragonal structure and to reduce the formation of second phases. However Bi-2223 phases also were formed at higher than 76$0^{\circ}C$ of pre-annealing temperature. The engineering critical current densities (Je) of Bi-22231Ag tapes were sintered at low oxygen partial pressure were higher than t hat of the wires sintered at air. We could achieve 6500 A/${cm}^2$ of Je for the tape that was initially kept at slightly higher temperature than that of normal heat treatment.

• Journal of Advanced Marine Engineering and Technology
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• 제15권1호
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• pp.85-95
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• 1991

All physical systems are nonlinear to some degree. The examples are relay, backlash, deadzone, saturation element and so on. In the linear control system design, it is useful method to restrict the nonlinearity to the linearity of system over the operation range. It is worth noting that nonlinearities may be intentionally introduced in to a system. A simple of an intentional non-linearity is the Bang-Bang controller which uses the On-Off relay. In this paper, an angular position servosystem made of a DC servomotor controlled by a microcomputer is discribed. Authors use two methods in the design of controller. The one is linear controller designed by the optimal feedback control theory only and the other is nonlinear controller designed by On-Off relay with optimal feedback control theory. To do the real time control, the controller is designed by using 16bit personal computer and A/D.D/A converter(12bit) is used in order to convert the signal. According to this way, the results from real time control are as follows. 2) Under the On-Off controller with hysterisis the influence of disturbance is considerably smaller than the linerar controller. 3) An increase in the sampling period has a destabilizing effect. 4)In the controller performance, the response time of the On-Off controller is longer than that of the linear controller. To close, we note that the On-Off controller with hysterisis is more attractive than the linear controller in the presence of the input limit.

• 한국정밀공학회지
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• 제14권3호
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• pp.98-106
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• 1997

In this paper, a new method of position synchronizing control is proposed for multi-axes driving system. The proposed position synchronizing control system is constituted with speed and synchronizing controller. The speed controller is aimed at the following to speed reference. Furthermore, it is designed to guarantee low sensitivity under some disturbance as well as robustness against model uncertainties using $H_{\infty}$technique. The synchronizing controller is designed to keep minimizing the position error using PID control law which is considered to reduce the dimension of transfer function in the control system. Especially, the proposed method can be easily conducted by controlling only slave axis speed, because it, has variable structure which is decided to master and slave axis by the sign of synchronizing error. Therfore, the master axis which is smaller influenced than another axes by disturbance can be controlled without reducing or increasing its speed for precise position synchronization. The effectiveness of the proposed method is sucessfully confirmed through many experiments.s.

• 한국연소학회지
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• 제20권3호
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• pp.35-42
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• 2015

Investigating coal combustion in a large-scale boiler using computational fluid dynamics (CFD) requires a combination of flow and reaction models. These models include a number of rate constants which are often difficult to determine or validate for particular coals or furnaces. Nonetheless, CFD plays an important role in developing new combustion technologies and improving the operation. In this study, the model selection and rate constants for coal devolatilization, char conversion, and turbulent reaction were evaluated for a commercial wall-firing boiler. The influence of devolatilization and char reaction models was found not significant on the overall temperature distribution and heat transfer rate. However, the difference in the flame shapes near the burners were noticeable. Compared to the coal conversion models, the rate constant used for the eddy dissipation rate of gaseous reactions had a larger influence on the temperature and heat transfer rate. Based on the operation data, a value for the rate constant was recommended.

• 대한한의학회지
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• 제37권3호
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• pp.123-130
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• 2016

설하 점액류 1례와 하마종 2례를 각각 담열(痰熱)과 어열(瘀熱)로 변증하여 온담탕과 도홍사물탕을 처방해 호전을 보였으며, 장기 관찰에서 재발하지 않아 한약 치료가 구강 점액류 치료의 대안이 될 수 있으리라 판단된다.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.372-379
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• 1991

E.coli ATCC 21990의 aminoglycoside-3'-phosphotransferase(APH(3'))의 신속하고 간편한 정량적 방법을 TLC densitometry를 이용하여 확립하였다. APH(3') 반응생산물인 3' 위치에 인산화된 kanamycin B(3'PKMB)는 silica gel plate에서 cnloroform-methanol-method-ammonia water (3:4:3) 전개용매로 반응물에서 분리되었고, 3'PKMB의 양은 ninhydrin으로 발색 후 densitometry로 측정하였다. APH(3')의 densitometric TLC assay는 좋은 정량적 결과와 재현성을 보였고, 3'-PKMB에 대한 감도는 1.56nmol이었으며 많은 시료의 분석이 한번의 실시로 가능하였다. 이 방법은 aminoglycoside 항생제의 불활화 효소 분석에 응용이 가능하리라 여겨진다.

• 한국동물위생학회지
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• 제15권2호
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• pp.109-120
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• 1992

330 Samples of the slaughtered cattle heart muscle were collected from the abattoirs of five regions in Kangwon - do to reveal the frequency of sarcocystis infections during January through December in 1991. The samples were inspected for bradyzoites by the trypsin digestion technique and the possitive samples were fed to dogs and cats for the detection of sporocysts shed in the feces. The results obtained were summarized as follows : 1. The infection rate of bovine Sarcocystis investigated from 330 samples was 43.6%. 2. It revealed that the infection rate of Sarrocystis increased gradully with the advance in the age, 14.5% in below two years, 26.1% in the three years, 30% in four years, 54.7% in five years, 74.4% in six years, 90% in seven years and 100% in older than eight years. 3. The cyst walls detected out from the heart muscles were less than l${\mu}{\textrm}{m}$ in thickness and the size of bradyzoites were $11.8{\times}2.8{\mu}m$ in average. 4. The size of sporocysts shed in the feces of dogs were $15.8{\times}9.8{\mu}m$ in average and the prepatent periods ranged from 12 to 16days. 5. Sarcorystis found in the bovine heart muscles were identified as Sascocystis cruzi ( Hasselman, 1923) , wenyon, 1926.

• 한국해양공학회지
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• 제13권3B호
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• pp.106-115
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• 1999

Modeling a discrete event system such as a sequential control system is difficult compared with a continuous system. Petri nets have been introduced as an analyzing and design tool for the discrete systems. One of the problems in its applications is that the model can not be analyzed easily in the case of large scale or complicated systems because of increase of the number of components of the system. To overcome this problem, some methods for dividing or reducing Petri nets have been suggested. In this paper, an approach for a hierarchical expression of Petri nets based on Sequential Function Chart(SFC) is proposed. A measuring tank system will be described as a typical kind of discrete systems. The system is modeled by sub Petri nets based on SFC in order to analyze and visualize efficiently about the dynamic behaviors of the system. Some numerical simulations using state equations are performed to prove the validity of the proposed method.