• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.10
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• pp.877-886
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• 2016

A validation study is conducted for the conceptual design and performance analysis of UH-60A Black Hawk in order to establish the conceptual design and performance analysis techniques for conventional helicopters using a single main rotor and a tail rotor. As a tool for conceptual design and analysis, NDARC(NASA Design and Analysis of Rotorcraft) is used for the present study. The conceptual design for UH-60A is successfully validated as compared with the target values. Then, various performance analyses in hover and forward flight are conducted for the UH-60A model obtained from the present design work, and they are compared well with the wind tunnel test, flight test, and previous analyses using various analysis tools. Through this validation work, the conceptual design and performance analysis techniques for the conventional helicopter are appropriately established.

• The Journal of Internal Korean Medicine
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• v.35 no.4
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• pp.519-531
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• 2014

Objectives: Diabetic nephropathy is the most common cause of end stage renal disease. Transforming growth factor (TGF)-${\beta}1$, type IV collagen, advanced glycation end-products (AGEs), and angiotensin II type 1 receptor (AT1) are the main factors of diabetic nephropathy. We investigated the effects of Prunus on renal function and histopathological changes of diabetic nephropathy rat model induced by unilateral nephrectomy and streptozotocin. Methods: Diabetes was induced in male Sprague-Dawley rats ($290{\pm}10g$) by injecting streptozotocin (55 mg/kg) into the tail vein after unilateral nephrectomy. Rats were divided into 3 groups (n=6): normal, control, and Prunus. After 8 weeks of oral administration of Prunus extract on the Prunus group from 3 days after streptozotocin injection, we checked weight, 24 hrs urine, blood biochemistry and renal tissue to evaluate renal function and histopathological changes by examining parameters including albuminuria, BUN, creatinine, cholesterol, low density lipoprotein (LDL), triglyceride, TGF-${\beta}1$, type IV collagen, AGEs, and AT1. We also measured mRNA expression of TGF-${\beta}1$, type IV collagen, AGEs, and AT1 by Real Time polymerase chain reaction (RT-PCR). Results: Prunus decreased the amount of 24 hrs proteinuria, and inhibited histopathological changes of diabetic nephropathy including the expression and accumulation of TGF-${\beta}1$, type IV collagen and AGEs which could promote development of diabetic nephropathy. Prunus also inhibited mRNA expression of TGF-${\beta}1$, type IV collagen. Conclusions: These findings suggest that Prunus might protect the renal function and inhibit the development of renal injury by regulating factors including TGF-${\beta}1$, type IV collagen, AGEs, except AT1, so Prunus can be used for diabetic patients to prevent the progression of diabetic nephropathy.

• Toxicological Research
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• v.24 no.1
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• pp.59-68
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• 2008

N-ethyl-N-nitrosoures (ENU) is effective in inducing hypermorphic mutation as well as hypomorphic and antimorphic mutations. Therefore, this mutagen is used to the production of mutant in the mice. In order to perform an effective ENU mutagenesis using BALB/cAnN mice, determination of optimal dosage and dosage regimen of ENU is necessary. And this study tried to develop a suitable screening method and searched for novel and various mutants as model animals in phenotypedriven ENU mutagenesis. We have carried out dosage regimen for mutagenizing dose of 200 mg/kg ENU in the BALB/c mice. Total screened mice were 30,133. As the results of Esaki and Cho's Phenotype Screening, we got 2,516 phenotypic and behavior abnormalities in $G_1,\;G_2\;and\;G_3$ mice. One hundred thirty five $G_1$ phenodeviants were tested for inheritance and 16 dominant mutants were discovered. Forty two recessive mutants were also found in tested 201 micropedigrees. Early-onset mutant mice included the dysmorphology of face, eye, tail, limb, skin, and foot and abnormal behavior like circling, swimming, head tossing, stiff-walking, high cholesterol level, and tremor etc. In this study we could effectively screen $G_3$ recessive mutants. The frequent and concise early-onset screening before weaning will be available for ENU mutagenesis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1694-1698
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• 2004

We hope to evaluate the effects of Sabaek-san for the bronchial asthma using assesment on the metrix metalloproteinase-9(MMP-9) after Sabaek-san was intravenously administered OVA-sensitized and -challenged mice. Seventy-two female mice, 8-10 weeks of age and free of murine specific pathogens, were used. Of the seventy-two mice, twenty-four mice were not sensitized and forty-eight mice were sensitized by intraperitoneal injection of OVA. Of the sensitized mice, twenty-four mice didn't administrate Sabaek-san and twenty-four administrated Sabaek-san. Mice were sensitized on days 1 and 14 by intraperitoneal injection of 20 fig OVA. On days 21, 22 and 23 after the initial sensitization, the mice were challenged for 30 minutes with an aerosol of 1% OVA in saline. Sabaek-san administered 200㎎/㎏ in the tail of the mouse, one time per day, for 7 days, beginning 14 days after first sensitization. Bronchoalveolar lavage was performed 72 hours after the last challenge, and total cell numbers in the BAL fluid were count. Also, level of MMP-9 in the BAL fluid were measured by Enzyme immunoassays and Western blot analysis. Enzyme immunoassay revealed that MMP-9 levels in the BAL fluids significantly increased 72 h after OVA inhalation compared with levels in the control group. After administration of the Sabaek-san, the levels of the MMP-9 in BAL fluids 72 h after OVA inhalation reduced dramatically. Western blot analysis revealed that MMP-9 levels increased in the all mice which were challenge with OVA without administered Sabaek-san compared the normal mouse. However, in the groups of the administered Sabaek-san, the MMP-9 level markedly decreased. Sabaek-san might be effect the treatment of the bronchial asthma as a inhibition of the MMP-9.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.6
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• pp.1475-1478
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• 2003

Purpose : We hope to evaluate the effectiveness of Citri Reticulatae Viride Pericarpium for the bronchial asthma using assesment on the vascular endothelial growth factor after Citri Reticulatae Viride Pericarpium was intravenously administered OVA-sensitized and -challenged mice. Material and methods: Eleven female mice, 8-10 weeks of age and free of murine specific pathogens, were used. Of the eleven mice, one mouse was not sensitized and ten mice were sensitized by intraperitoneal injection of OVA. Of the sensitized mice, three mice didn't administrate Citri Reticulatae Viride Pericarpium and seven mice administrated Citri Reticulatae Viride Pericarpium. Mice were sensitized on days 1 and 14 by intraperitoneal injection of 20 ㎍ OVA. On days 21, 22, and 23 after the initial sensitization, the mice were challenged for 30 minutes with an aerosol of 1 % OVA in saline. Citri Reticulatae Viride Pericarpium administered 200mg/kg in the tail of the mouse, one time per day, for 7 days, beginning 14 days after first sensitization. Bronchoalveolar lavage was performed 72 hours after the last challenge, and level of VEGF in the BAL fluid were measured by Western blot analysis. Results: Western blot analysis revealed that VEGF protein levels were increased in the all three mice which were challenge with OVA without administered Chung-pi compared the normal mouse. However, in the groups of the administered Chung-pi, the VEGF protein level markedly decreased in six of seven mice. Conclusion : Citri Reticulatae Viride Pericarpium might be effect the treatment of the bronchial asthma as a inhibition of the VEGF.

• The Korean Journal of Applied Statistics
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• v.20 no.2
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• pp.291-311
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• 2007

With a series of unexpected huge losses in the financial markets around the world recently, especially in the insurance market with extreme loss cases such as catastrophes, there is an increasing demand for risk management for extreme loss exposures due to high unpredictability of those risks. For extreme risk management, to make a maximum use of the information concerning the tail part of a loss distribution, EVT(Extreme Value Theory) modelling nay be the best to analyze extreme values. The Extreme Value Theory is widely used in practice and, especially in financal markets, EVT modelling is getting popular to analyBe the effects of extreme risks. This study is to review the significance of the Extreme Value Theory in risk management and, focusing on analyzing insurer's risk capital, extreme risk is measured using the real fire loss data and insurer's specific amount of risk capital is figured out to buffer the extreme risk.

• Advances in Traditional Medicine
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• v.8 no.3
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• pp.243-251
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• 2008

The effect of alcoholic extracts of Costus specious (Family: Zingiberaceae) was evaluated in experimental models of pain and inflammation. Oral administration of 100, 200 and 300 mg/kg of C. specious extracts were used for the above study. Crude extracts of C. specious (300 mg/kg dose) showed maximum time needed for the response against thermal stimuli ($7.242\;{\pm}\;0.532\;s$) which is comparable to diclofenac sodium ($8.471\;{\pm}\;0.25\;s$) in the hot plate test. The MPH (Maximum Possible Analgesia) has been found to be 14.285 for 300 mg/kg dose of the crude extract while the MPH for diclofenac was 15.857 after 60 min of administration in the hot tail-flick method. The crude extract at 300 and 200 mg/kg doses showed significant reduction in acetic acid induced writhings in mice with a maximum effect of 59.661% reduction at 300 mg/kg dose which is comparable to standard diclofenac sodium (73.4%). Alcoholic extract of C. specious showed significant inhibition in serotonin and egg albumin induced hind paw oedema in rats at 100, 200 and 300 mg/kg of the crude extracts respectively (Serotonin induced edema 44.22; 53.75; 58.51%; egg albumin induced edema - 41.317; 53.892; 59.880% inhibition after 4 h respectively). The antiinflammatory effects showed by the extract were comparable to that of standard indomethacin 5 mg/kg (Serotonin induced edema 77.56%; egg albumin induced edema 77.844% inhibition after 4 h). These results suggest that the extract possesses both the anti-inflammatory and analgesic activity on mice and rat model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.8
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• pp.797-806
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• 2008

In a double-passage cascade apparatus, only two blades are installed in order to increase the accuracy of experimental result by applying bigger blade than the size of multi-blades on the same apparatus. However, this causes difficulties to make correct periodic condition. In this study, sidewalls are designed to meet periodic condition without removing the operating fluid or adjusting tail boards. Surface Mach number on the blade surface is applied to a responsible variable, and 12 design variables which are related with sidewall profile control are selected. A gradient-based optimization is adopted for wall design and CFX-11 is used for the internal flow computation. The computed result shows that it could obtain the same flow structure by modifying only the sidewalls of the double-passage cascade apparatus.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.77-77
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• 2003

Chimeric animals are referred to as an organism composed of tissues derived from more than one species. In order to examine if a pluripotency of embryonic stem cells can cross the limitation of a species, we tried to establish human-mouse chimeric animals. Human embryonic stem cells were genetically modified to express eGFP using eukaryonic expression vector pcDNA 3.1 (In Vitrogene) for an easy identification. After selection with neomycin, approximately 15 cells were implanted into mouse blastocoele cavity. Ten chimeric blastocysts were transferred to one of the uterine horn of 2.5 days pesudopregnent ICR female. Out of 272 blastocysts transferred to pseudopregnant recipients 20 live newborn were obtained after 20 days. When newborn were obtained, pups were quickly removed immersed into 4% PFA. By histological examination using fluorescent microscope, green fluorescence was observed from the liver, heart, and spleen in newborn mice. Three weeks after born, presence of eGFP sequence within mouse genome (tail and kidney) was reconfirmed by PCR. eGFP sequence was amplified from the progenies of the animal suggesting a genetic transmission of the transgene. These chimeric mice having human cells at the beginning of development, are expected to recognize human cells as “self”, therefore, human cells or tissues will be able to escape the immunological surveillance of the host if grafted into the animal. These animals will serve as a good model system for studying the graft rejection in tissue transplantation and the potential of the cells to work well in many human disease.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.303-314
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• 2004

In this paper we report some properties of inner magnetospheric structure inferred from the T01_s code, one of the latest magnetospheric models by Tsyganenko. We have constructed three average storms representing moderate, strong, and severe intensity storms using 95 actual storms. The three storms are then modelled by the T01_s code to examine differences in magnetic structure among them. We find that the magnetic structure of intense storms is strikingly different from the normal structure. First, when the storm intensity is large, the field lines anchored at dayside longitudinal sectors become warped tailward to align to the solar wind direction. This is particularly so for the field lines anchored at the longitudinal sectors from postnoon through dusk. Also while for the moderate storm the equatorial magnetic field near geosynchronous altitude is found to be weakest near midnight sector, this depression region expands into even late afternoon sector during the severe storm. Accordingly the field line curvature radius at the equator in the premidnight geosynchronous region becomes unusually small, reaching down to a value less than 500 km. We attribute this strong depression and the dawn-dusk asymmetry to the combined effect from the enhanced tail current and the westward expansion/rotation of the partial ring current.