• Proceedings of the KOSOMBE Conference
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• v.1994 no.05
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• pp.139-141
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• 1994

• 한국연소학회:학술대회논문집
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• 2000.05a
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• pp.76-84
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• 2000

A numerical study was conducted for the investigation of thermal choking process in a model scramjet engine based on the experimental results at the Australian National University. The results of numerical simulation showed that thermal choking process could be related to the interaction between hypersonic flow and fuel-air mixing process. Especially, we could make sure that turbulent mixing was most important parameter to the thermal choking process.

• KCID journal
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• v.9 no.2
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• pp.51-58
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• 2002

The purpose of this study is to construct a Water Quality Management System (WQMS) for the Saemangeum watershed based on the linkage of water quality model, i .e. QUALfE, and GIS database to estimate water quality effectively in this area. There are three

• Electric Engineers Magazine
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• s.273
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• pp.32-36
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• 2005

최근 일부 선진국을 중심으로 대용량 전력제어용 반도체 소자와 제어기술의 발달로 인해 전력전자 반도체 소자인 IGBT(Insulated Gate Bi-polar Transistors) 등을 사용한 승강압형 컨버터 방식으로 동기발전기 계자전류를 제어하는 특이한 모델이 발전기 출력전압을 보다 속응성있게 제어함은 물론, 신뢰성 있고 안정적으로 제어 할 수 있는 방법으로 등장함에 따라 이에 대한 기술적 연구가 진행되고 있다. 이에 따라 본 고에서는 발전기 제어시스템의 개요, 국내외 기술개발 동향과 개발시스템의 구성, 주요기능 그리고 발전소 현장 적용 전에 시스템의 신뢰도 확보를 위해 전동발전기(M-G Set)를 이용한 시스템의 모의시험 결과와 향후 발전기 제어시스템의 발전 전망 등을 그회에 걸쳐 기술한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.373.1-373
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• 2002

Impact is the most common type of dynamic loading conditions that give rise to impulsive forces and affects the vibrational characteristics of mechanical systems. Since the impact force and response are measured indirectly through the sensors, it is difficult to predict the impact force and acceleration. In this study, contact force model based on the Hertz law is proposed in order to predict the impact force correctly. (omitted)

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.668-676
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• 1992

For the purpose of optimizing poly-l3-hydroxybutyrate (PHB) production from Alcaligenes eutrophus, two-stage fed-batch culture was adopted. In this system, specifk growth rate was maximized during the first stage whereas specific production rate was maximized during the second stage. The optimal concentrations of glucose and ammonium chloride were 16.6 and 0.54 g/I in the growth stage and 20.0 and 0.07 g/l in the production stage, respectively. Proportional feedback control considering time lag was suggested for PHB production process and a simulator was developed for real-time control purpose.

• Journal of Korean Medicine Rehabilitation
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• v.28 no.1
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• pp.19-31
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• 2018

Objectives The object of this study was to investigate the antioxidative and antiinflammatory effects of Jinmu-tang extract (JMT) on the Monosodium iodoacetate (MIA)-induced rat osteoarthritis. Methods To investigate the antioxidant capacities of JMT, we measured the total polyphenol and flavonoid, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-Azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity. To evaluate the antioxidative and antiinflammatory effects of JMT, the rats were divided into 5 groups (n=8). Normal group was not induced by MIA and treated at all (N), control group was induced by MIA and not treated at all (Con), positive control group was induced by MIA and orally administered indomethacin 5 mg/kg (Indo) and experimental groups were induced by MIA and orally administered JMT 100 mg/kg (JMT100) and JMT 200 mg/kg (JMT200) for 4 weeks. The changes of anti-type II collagen antibody in serum, heme oxygenase-1 (HO-1), phosphorylated inhibitor of ${\kappa}B{\alpha}$ ($p-I{\kappa}B{\alpha}$), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and tumor necrosis factor alpha ($TNF-{\alpha}$) in knee joint tissue and histopathological observation (Hematoxylin & Eosin and Safranin-O stain) were measured. Results Total polyphenol and flavonoid levels of JMT were $26.90{\pm}0.33mg/g$ and $6.02{\pm}0.34mg/g$. $IC_{50}$ of L-ascorbic acid and JMT of DPPH radical scavenging activity were $1.35{\pm}0.07{\mu}g/ml$ and $52.95{\pm}0.97{\mu}g/ml$. $IC_{50}$ of L-ascorbic acid and JMT of ABTS radical scavenging activity were $3.18{\pm}0.02{\mu}g/ml$ and $91.49{\pm}1.74{\mu}g/ml$. In serum, the anti-type II collagen antibody levels of JMT100 and JMT200 groups were decreased significantly. In knee joint tissue, the HO-1 level of JMT200 was increased significantly. The $p-I{\kappa}B{\alpha}$ and $TNF-{\alpha}$ levels of JMT200 were decreased significantly. The COX-2 and iNOS levels of JMT groups were decreased significantly. In histopathological observation, in comparison with Con, synovial tissue, cartilage and proteoglycan of JMT100 and JMT200 were well preserved. Conclusions According to the results, It is considered that JMT has antioxidant and antiinflammatory effects for MIA-induced rat osteoarthritis, so it could be applied to osteoarthritis treatment.

• The Korean Journal of Pain
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• v.20 no.1
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• pp.8-14
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• 2007

Background: Anticonvulsants and antidepressants are adjuvant analgesic drugs that are used widely for treating chronic neuropathic pain syndromes. The combined analgesic effect of gabapentin and milnacipran was investigated with a rat neuropathic pain model. Methods: The rat neuropathic pain model was made by ligating the spinal nerves (L5 and L6). An intrathecal catheter was inserted into the subarachnoid space. Tactile allodynia was tested with the up-down method using von Frey hair. We determined the antiallodynic effect of intraperitoneal (I.P.) and intrathecal (I.T.) gabapentin. The combined effect of I.P. gabapentin (50 mg/kg) and milnacipran (0, 10 and 30 mg/kg) was investigated. Results: Intraperitoneal and intrathecal administration of gabapentin increased the threshold for tactile allodynia (the ED50 was 60.6 mg/kg and $45.5{\mu}g$, respectively). Co-administration of I.P. milnacipran increased the antiallodynic effect of I.P. gabapentin in a dose-dependent fashion. Conclusion: The combined administration of milnacipran and gabapentin may increase the total analgesic effect during treatment of neuropathic pain.

• Journal of Korean Academy of Nursing
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• v.40 no.4
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• pp.580-588
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• 2010

Purpose: The purpose of this study was to examine effects of decreased locomotor activity on mass, Type I and II fiber cross-sectional areas of ipsilateral and contralateral hindlimb muscles 21 days after establishing the Parkinson's disease rat model. Methods: The rat model was established by direct injection of 6-hydroxydopamine (6-OHDA, 50 ${mu}g$) into the left substantia nigra after stereotaxic surgery. Adult male Sprague-Dawley rats were assigned to one of two groups; the Parkinson's disease group (PD; n=17) and a sham group (S; n=8). Locomotor activity was assessed before and 21 days after the experiment. At 22 days after establishing the rat model, all rats were anesthetized and soleus and plantaris muscles were dissected from both ipsilateral and contralateral sides. The brain was dissected to identify dopaminergic neuronal death of substantia nigra in the PD group. Results: The PD group at 21 days after establishing the Parkinson's disease rat model showed significant decrease in locomotor activity compared with the S group. Weights and Type I and II fiber cross-sectional areas of the contralateral soleus muscle of the PD group were significantly lower than those of the S group. Conclusion: Contralateral soleus muscle atrophy occurs 21 days after establishing the Parkinson's disease rat model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.347-349
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• 2014

Model verification and validation (V&V) is a current research topic to build computational models with high predictive capability by addressing the general concepts, processes and statistical techniques. The hypothesis test for validity check is one of the model validation techniques and gives a guideline to evaluate the validity of a computational model when limited experimental data only exist due to restricted test resources (e.g., time and budget). The hypothesis test for validity check mainly employ Type I error, the risk of rejecting the valid computational model, for the validity evaluation since quantification of Type II error is not feasible for model validation. However, Type II error, the risk of accepting invalid computational model, should be importantly considered for an engineered products having high risk on predicted results. This paper proposes a technique named as the response-adaptive experimental design to reduce Type II error by adaptively designing experimental conditions for the validation experiment. A tire tread block problem and a numerical example are employed to show the effectiveness of the response-adaptive experimental design for the validity evaluation.