• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제23회 추계학술대회 논문집
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• pp.43-46
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• 2004

에너지원으로써 압축공기만을 사용하는 공기역학 점화기의 주요 구성요소 중 노즐부에 관한 실험 연구로써 노즐로 초음속 노즐과 스파이크 노즐을 사용하여 각각의 구조적인 특성을 소개하고 최대 가열온도를 주요 성능 특성으로 하여 고찰한 실험결과를 나타내고 있다. 초음속 노즐은 기존의 음속노즐의 사용에 비해 동일한 유량으로 보다 높은 온도에 더 마르고 도달하며, 스파이크 노즐의 사용을 통해 작동유량의 넓은 변화범위에서도 근 성능저하 없이 사용할 수 있는 특성을 확인할 수 있다.

• 한국정보기술학회 영문논문지
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• 제9권1호
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• pp.103-113
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• 2019

Motivation: Polymerized actin-based cytoskeletal structures are crucial in shape, dynamics, and resilience of a cell. For example, dynamical actin-containing ruffles are located at leading edges of cells and have a significant impact on cell motility. Other filamentous actin (F-actin) bundles, called stress fibers, are essential in cell attachment and detachment. For this reason, their mechanistic understanding provides crucial information to solve practical problems related to cell interactions with materials in tissue engineering. Detecting and counting actin-based structures in a cellular ensemble is a fundamental first step. In this research, we suggest a new method to characterize F-actin wrapping fibers from confocal fluorescence image stacks. As fluorescently labeled F-actin often envelope the fibers, we first propose to segment these fibers by diminishing an energy based on maximum flow and minimum cut algorithm. The actual actin is detected through the use of bilateral filtering followed by a thresholding step. Later, concave actin bundles are detected through a graph-based procedure that actually determines if the considered actin filament is enclosing the fiber.

• Journal of Ginseng Research
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• 제39권3호
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• pp.206-212
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• 2015

Background: Ginseng total saponin (GTS) contains various ginsenosides. These ginsenosides are widely used for treating cardiovascular diseases in Asian communities. The aim of this study was to study the effects of GTS on cardiac injury after global ischemia and reperfusion (I/R) in isolated guinea pig hearts. Methods: Animals were subjected to normothermic ischemia for 60 minutes, followed by 120 minutes of reperfusion. GTS significantly increased aortic flow, coronary flow, and cardiac output. Moreover, GTS significantly increased left ventricular systolic pressure and the maximal rate of contraction ($+dP/dt_{max}$) and relaxation ($-dP/dt_{max}$). In addition, GTS has been shown to ameliorate electrocardiographic changes such as the QRS complex, QT interval, and RR interval. Results: GTS significantly suppressed the biochemical parameters (i.e., lactate dehydrogenase, creatine kinase-MB fraction, and cardiac troponin I levels) and normalized the oxidative stress markers (i.e., malondialdehyde, glutathione, and nitrite). In addition, GTS also markedly inhibits the expression of interleukin-$1{\beta}$ (IL-$1{\beta}$), IL-6, and nuclear factor-${\kappa}B$, and improves the expression of IL-10 in cardiac tissue. Conclusion: These data indicate that GTS mitigates myocardial damage by modulating the biochemical and oxidative stress related to cardiac I/R injury.

• The Korean Journal of Physiology and Pharmacology
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• 제17권4호
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• pp.283-289
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• 2013

This study was designed to evaluate the protective effect of Korean red ginseng (KRG) against ischemia/reperfusion (I/R) injury in isolated guinea pig heart. KRG has been shown to possess various ginsenosides, which are the major components of Panax ginseng. These components are known naturally occurring compounds with beneficial effects and free radical scavenging activity. The heart was induced to ischemia for 60 min, followed by 120 min reperfusion. The hearts were randomly allocated into five groups (n=8 for each group): normal control (N/C), KRG control, I/R control, 250 mg/kg KRG group and 500 mg/kg KRG group. KRG significantly increased hemodynamics parameters such as aortic flow, coronary flow and cardiac output. Moreover, KRG significantly increased left ventricular systolic pressure (LVSP), the maximal rate of contraction (+dP/$dt_{max}$) and maximal rate of relaxation (-dP/$dt_{max}$). Also, treatment of KRG ameliorated electrocardiographic index such as the QRS, QT and RR intervals. Moreover, KRG significantly suppressed the lactate dehydrogenase, creatine kinase-MB fraction and cardiac troponin I and ameliorated the oxidative stress markers such as malondialdehyde and glutathione. KRG was standardized through ultra performance liquid chromatograph analysis for its major ginsenosides. Taken together, KRG has been shown to prevent cardiac injury by normalizing the biochemical and oxidative stress.

• 한국인터넷방송통신학회논문지
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• 제20권3호
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• pp.147-152
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• 2020

야구배제문제(BEP)는 잔여경기를 모두 승리하더라도 리그전에서 최다승 팀이 되지 못하는 팀들을 잔여경기 진행없이 경기에서 배제시키고 시즌을 조기 종료시키는 문제이다. 이 문제는 최대흐름-최소절단 정리를 적용하여 해를 구하고자 하였다. 그러나 이 방법은 어느 한 팀이 아닌 다수의 팀을 배제할 수 있는 경우 반복적으로 망을 구성해 최소절단을 구하는 문제점을 갖고 있다. 본 논문에서는 승리한 경기 수와 잔여 경기 수 합 오름차순으로 정렬시켜, 하위 성적 1/2팀들을 배제 후보 팀 집합 K로 설정하고, 이 팀을 배제할지 여부를 결정하는 부분집합 R이 존재 유무를 판단하는 가장 쉽고 단순하면서도 빠른 계산 방법을 제시하였다. 제안된 알고리즘을 다양한 실험 데이터에 적용한 결과 모든 데이터에 존재하는 모든 배제 팀을 빠르고 정확하게 결정할 수 있었다.

• 한국산학기술학회논문지
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• 제15권3호
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• pp.1294-1298
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• 2014

향후 제작 될 솔레노이드 구조의 방향을 제시하고자 실험 및 유동 특성에 대한 비교 분석 연구가 진행 되어졌다. 실험값과 해석값의 비교 분석은 ANSYS CFD와 전자식 측정 기구를 이용하여 수행하였다. 구조의 3D 모델링은 CATIA V5R18을 이용하였으며, 유동구간의 격자 생성은 ICEM CFD 프로그램을 사용하였다. 유동해석 분석은 수치해석 프로그램인 ANSYS CFD를 이용하여 실험값에 대한 검증이 진행되었다. 실험값을 통해 정밀 필터구간에서 나타난 유량은 $0-10{\ell}/min$ 으로 나타났으며 유동해석결과 최대 $0.18{\ell}/min$로 나타났다. 유동 해석 결과와 실험값의 비교분석을 통해 유동환경에 보다 효율적인 솔레노이드 구조를 제시 할 수 있었다.

• 대한통합의학회지
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• 제2권3호
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• pp.65-73
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• 2014

Purpose: The purpose of this study was to identify the effect of a kinesio tape on inspiratory muscle training(IMT) to improve muscle strength, endurance and pulmonary function. Methods: Healthy 20 males were divided into IMT group (control group) and IMT with tape group (experimental group). The same IMT program was applied to both groups using the Respifit S for four weeks, three times a week, a total 12 times. To exprimental group, kinesio tape was applied on the inspiratory agonist diaphragm and the accessory inspiratory muscle scalene, sternocleidomastoid, pectoralis minor. The inspiratory pulmonary muscle strength was measured by the maximal inspiratory pressure (PI max) and minute volume (MV) using the Respifit S and the pulmonary function were measured peak expiratory flow (PEF), forced vital capacity (FVC), forced expiratory volume in 1sec (FEV1), FEV1/FVC using the Spirometer and compared before and after. Results: Results showed that the PI max in the two groups increased significantly and experimental group increased more effectively than that of control group. However, only MV showed a significant increase in experimental group but was not significantly different between the two groups. PEF and FEV1/FVC are significantly increased in both groups, but they did not make much difference between two groups, and the FVC for the two groups did not increase significantly. FEV1 increased significantly only with control group, but did not make a difference with experimental group. Conclusion: These result show that the PI max value for experimental group increased significantly than that of control group. Therefore kinesio tape maximizes inspiratory muscle exercise effect on muscle strength improvement. However, because of the short experimental period and difficulty in subject control, increase values of the others did not show a significant difference. In other words, kinesio tape did not show maximizing the inspiratory muscle exercise effect to improve endurance and pulmonary function.

• 약학회지
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• 제41권6호
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• pp.829-836
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• 1997

Studies on the effect of quinones on cardiac function has been conducted with normal hearts. But not with injured hearts, I.e. ischemia/reperfusion-injured heart. Quinone compounds are known to produce oxygen free radicals during metabolism, and for this reason, quinones are implicated in the aggravation of ischemia/reperfusion injury or cardioprotection, as in the case of ischemic preconditioning depending on the experimental conditions. The present study was carried out to examine the effect of 2-chloro-3-(4-cyanophenylamino)-1.4-naphthoquinone (NQ-Y15) on cardiac function of ischemic/reperfused and normal rat hearts. In isolated perfused hearts, various functional parameters such as left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (EDP) and maximum positive and negative dP/dt ($[\pm}dP/dt_{max}$), time to contracture, heart rate (HR) and coronary flow rate (CFR) were measured before and 30 min after dosing and following 25 min ischemia/30min reperfusion. NQ-Y15 increased LVDP, +dP/$d_{max}$and -dP/$dt_{min}$ by 18%. 30%, and 40%, respectively. There were no significant changes in other haemodynamic parameters. After ischemia/reperfusion injury, pretreatment with NQ-Y15 induced a significant decrease in LVDP and $[\pm}dP/dt_{max}$, but an increase in EDP. LDH-release was not significantly increased. These results suggested that NQ-Y15 may augment the ventricular contractility but it makes hearts more vulnerable to ischemia/reperfusion injury.

• 약학회지
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• 제36권3호
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• pp.259-268
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• 1992

A procedure for the determination of KR-30075 and its metabolites in plasma and urine by high performance liquid chromatography is described. For the study of pharmacokinetic properties of KR-30075, a new PDE III inhibitor, the plasma concentration and urinary excretion after an oral administration of KR-30075 (4 mg/kg) in the male rat (Sprague Dawley) were determined by high performance liquid chromatography. The best extraction efficiency of KR-30075 and KR-30072 is obtained with ethyl ether adjusted to pH 4.0. Retention times of both KR-30072 and KR-30075 were within 5 min and resolution was complete at the flow rate of 1.0 ml/min. The sensitivity and specificity of this HPLC assay appears to be satisfactory for the pharmacokinetic study of KR-30075 and its metabolites. One-compartment open model with first-order absorption was applied to evaluate the pharmacokinetic parameters of KR-30075 according to Minimum AIC Estimation. $T_{max}$ was 1 hr, $C_{max}$ was $0.789{\pm}0.31\;{\mu}g/ml$ and elimination half $T_{1/2}$ was 6.31 min after oral administration of 4 mg/kg KR-30075 to male rats.

• 한국의류학회지
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• 제40권2호
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• pp.305-314
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• 2016

This paper investigated the applicable possibility of PTT and wool staple fibers to the air vortex system as high quality yarns for a high emotional and comfort garment. It was found that the tactile hand of vortex yarn knitted fabrics was harsher than ring and compact yarns knitted fabrics. It was observed that formability and sewability of air vortex yarn knitted fabrics seemed worse than ring and compact yarns due to low tensile and compressional resilience and high bending and shear hysteresis of air vortex yarn knitted fabrics. It revealed that wicking and drying rates of air vortex yarn knitted fabric were better than ring and compact yarns; in addition, the heat keepability of vortex yarn knitted fabric was higher than ring and compact yarns due to low thermal conductivity and max heat flow rate ($Q_{max}$). Any difference of thermal shrinkage between air vortex and ring yarn knitted fabrics was not shown, but pilling characteristic of air vortex yarn knitted fabric was superior. However, it was shown that wicking, drying, thermal property and pilling characteristics of air vortex yarn knitted fabric were superior due to air vortex yarn structure with parallel fibers in the core part and periodical and fasciated twists in the sheath part of the yarns.