• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2008년도 학술대회
• /
• pp.229-232
• /
• 2008

This study presents a numerical procedure to optimize the shape of stepped circular pin-fins to enhance turbulent heat transfer. The KRG method is used as an optimization technique with Reynolds-averaged Navier-Stokes analysis of fluid flow and heat transfer with shear stress transport turbulent model. The objective function is defined as a linear combination of heat transfer and friction loss related terms with a weighting factor. Ten training points are obtained by Latin Hypercube Sampling for two design variables. Optimum shape has been successfully obtained with the increased objective function.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2008년 추계학술대회논문집
• /
• pp.229-232
• /
• 2008

This study presents a numerical procedure to optimize the shape of stepped circular pin-fins to enhance turbulent heat transfer. The KRG method is used as an optimization technique with Reynolds-averaged Navier-Stokes analysis of fluid flow and heat transfer with shear stress transport turbulent model. The objective function is defined as a linear combination of heat transfer and friction loss related terms with a weighting factor. Ten training points are obtained by Latin Hypercube Sampling for two design variables. Optimum shape has been successfully obtained with the increased objective function.

• Journal of Ginseng Research
• /
• 제44권6호
• /
• pp.790-798
• /
• 2020

Background: Beneficial effects of Korean Red Ginseng (KRG) on polycystic ovarian syndrome (PCOS) remains unclear. Methods: We examined whether pretreatment (daily from 2 hours before PCOS induction) with KRG extract in water (KRGE; 75 and 150 mg/kg/day, p.o.) could exert a favorable effect in a dehydroepian-drosterone (DHEA)-induced PCOS rat model. Results: Pretreatment with KRGE significantly inhibited the elevation of body and ovary weights, the increase in number and size of ovarian cysts, and the elevation of serum testosterone and estradiol levels induced by DHEA. Pretreatment with KRGE also inhibited macrophage infiltration and enhanced mRNA expression levels of chemokines [interleukin (IL)-8, monocyte chemoattractant protein-1), proinflammatory cytokines (IL-1β, IL-6), and inducible nitric oxide synthase in ovaries induced by DHEA. It also prevented the reduction in mRNA expression of growth factors (epidermal growth factor, transforming growth factor-beta (EGF, TGF-β)) related to inhibition of the nuclear factor kappa-light-chain-enhancer of activated B cell pathway and stimulation of the nuclear factor erythroid-derived 2-related factor 2 pathway. Interestingly, KRGE or representative ginsenosides (Rb1, Rg1, and Rg3(s)) inhibited the activity of inflammatory enzymes cyclooxygenase-2 and iNOS, cytosolic p-IκB, and nuclear p-nuclear factor kappa-light-chain-enhancer of activated B in lipopolysaccharide-induced RAW264.7 cells, whereas they increased nuclear factor erythroid-derived 2-related factor 2 nuclear translocation. Conclusion: These results provide that KRGE could prevent DHEA-induced PCOS via antiinflammatory and antioxidant activities. Thus, KRGE may be used in preventive and therapeutic strategies for PCOS-like symptoms.

• Journal of Ginseng Research
• /
• 제38권4호
• /
• pp.256-263
• /
• 2014

Background: Korean Red Ginseng (KRG) is known to have antianxiety properties. This study was conducted to investigate the anxiolytic effects of KRG extract (KRGE) during ethanol withdrawal (EW) and the involvement of the mesoamygdaloid dopamine (DA) system in it. Methods: Rats were treated with 3 g/kg/d of ethanol for 28 d, and subjected to 3 d of withdrawal. During EW, KRGE (20 mg/kg/d or 60 mg/kg/d, p.o.) was given to rats once/d for 3 d. Thirty min after the final dose of KRGE, anxiety-like behavior was evaluated in an elevated plus maze (EPM), and plasma corticosterone (CORT) levels were determined by a radioimmunoassay (RIA). In addition, concentrations of DA and 3,4-dihydroxyphenylacetic acid (DOPAC) in the central nucleus of the amygdala (CeA) were also measured by high performance liquid chromatography (HPLC). Results: The EPM test and RIA revealed KRGE inhibited anxiety-like behavior and the over secretion of plasma CORT during EW. Furthermore, the behavioral effect was blocked by a selective DA D2 receptor (D2R) antagonist (eticlopride) but not by a selective DA D1 receptor (D1R) antagonist (SCH23390). HPLC analyses showed KRGE reversed EW-induced decreases of DA and DOPAC in a dose-dependent way. Additionally, Western blotting and real-time polymerase chain reaction (PCR) assays showed that KRGE prevented the EW-induced reductions in tyrosine hydroxylase (TH) protein expression in the CeA and TH mRNA expression in the ventral tegmental area (VTA). Conclusion: These results suggest that KRGE has anxiolytic effects during EW by improving the mesoamygdaloid DA system.

• 한국정보시스템학회:학술대회논문집
• /
• 한국정보시스템학회 2003년도 춘계학술대회
• /
• pp.219-239
• /
• 2003

지난 몇 년간 인터넷의 확산과 더불어 기업 환경에는 많은 변화가 있었다. 그 중 하나가 전자적인 형태로 접근할 수 있는 정보 양의 급증이라 할 수 있다. (Martin White, 2000 : 신학철, 2001) E-business 환경에서 이처럼 정보의 양이 급증함에 따라 정보의 효율적인 활용은 기업의 주요 경쟁원천이 되고 있다. 정보의 중요성을 깨달은 기업들은 운영효율성 증가를 위해 백오피스시스템과 프론트오피스시스템 등에 많은 투자를 했다. (안승용, 2001) 하지만 새로운 정보시스템 도입 시 레거시시스템과의 통합을 고려하지 않아 업무효율성 향상을 위한 정보기술이 역으로 업무수행을 저해하는 결과를 초래했다. (Jaydip, 2002) 예컨대 기업의 각 시스템간에 정보의 일관성이 결여되어 있고, 필요한 정보 역시 기업내 여러 시스템에 산재되어 있어 정보의 이용 면에서 효율성이 떨어지는 문제에 직면하게 된 것이다 따라서 기업은 각 시스템에 산재해 있는 정보사용의 효율성을 놀이기 위해 기업 내 다양한 정보시스템간 통합의 필요성을 인식함에 따라 이전까지 분산 환경이던 IT환경이 점차 기업정보포탈(Enterprise Information Portal: EIP)같은 통합 환경으로 바뀌게 되었다. (KRG Report, 2002) EIP는 현재와 E-business를 준비하는 기업에 중요한 관심사항으로 떠오르고 있으며 현재 IBM, MS 같은 글로벌 기업 뿐 아니라 다수의 국내 업체들도 통합 솔루션 시장 진출해 경쟁을 벌이고 있다. 본 논문에서는 EIP의 개념을 살펴보고 기존의 정보시스템과 EIP 관련 연구를 기반으로 새롭게 부상하고 있는 EIP의 성과를 시스템 품질과 정보품질로 측정하여 이들 요인이 EIP사용자의 직무성과에 미치는 영향에 관해 연구하였다. 본 논문은 EIP를 도입한 기업을 대상으로 EIP성과에 대한 연구를 진행하여 EIP를 도입하거나 구현중인 기업에게 적합한 경영관리적 방향을 제시할 수 있을 것이다.

• 대한한의학회지
• /
• 제27권3호
• /
• pp.1-13
• /
• 2006

The purpose of this study was to investigate the anti-obesity effects of crude saponin (CS) in Korean red ginseng (KRG) on rats fed a high fat (HF) diet. Methods: Male Sprague-Dawley (SD) rats were divided into a normal diet group and a high-fat (HF) diet group. The HF diet group became obese from being fed a HF diet over five weeks. The normal diet group were fed a normal diet. Each CS group of the normal diet group and HF diet group was administered CS (200 mg/kg, i.p.) for three weeks, the control group of both types was administered normal saline (1ml/kg, i.p.) instead of CS. Each group had 5 rats. Results: After administration of CS, the body weight, food consumption, adipose tissues, and expression of appetite peptides such as leptin and neuropeptide-Y (NPY) were investigated in the HF diet group as well as the normal diet group. Administration of CS reduced body weight, food intake, and fat content in the HF and normal diet groups. After CS administration, NPY expression and leptin were lower in the HF diet group. Conclusions: Our results suggest that CS may be useful in the treatment of obesity, especially of type qixu (氣虛).

• Journal of Ginseng Research
• /
• 제19권1호
• /
• pp.17-21
• /
• 1995

A study was designed to investigate the effectiveness of Korean Red Ginseng (ERG) as an oral agent for erectile dysfunction (EF), which was compared to that of placebo and trazodone. Patients who were believed to have EF of mild or non-organic etiologies, randomized into 3 groups to receive 600 mg KRG 3 times daily (group A), placebo (group B) and 25mg trazodone once a day after evening (group C). All agents were given orally. Ninety patients, composed of 30 in each group, were included and analyzed only when clinical follow-up could be achieved at the end of the study for at least 3 months. There were no significant differences(p>0.05) between each group in mean age (43.7 years), duration of EF (5.8 years), the state of marriage (married : 80 patients) and duration of marriage (18.2 years). In group A, the parameters such as rigidity and tumescence on erection, early detumescence, libido and patient's satisfaction were significantly more effective than that of other group (p<0.05). But there were no significant differences in the parameters such as the frequency of coitus, premature ejaculation and morning erection between 3 groups (p>0.05). The efficacy achieved with KGR (60%) was significantly higher (p<0.05) than that of placebo (30%) and trazodone (30%). There were no significant changes on level of serum testosterone and type of AVS-penogram in group A. No side effect was demonstrated in all patients.

• Smart Structures and Systems
• /
• 제32권1호
• /
• pp.61-81
• /
• 2023

This study presents an ensemble learning based Bayesian model updating approach for structural damage diagnosis. In the developed framework, the structure is initially decomposed into a set of substructures. The autoregressive moving average (ARMAX) model is established first for structural damage localization based structural motion equation. The wavelet packet decomposition is utilized to extract the damage-sensitive node energy in different frequency bands for constructing structural surrogate models. Four methods, including Kriging predictor (KRG), radial basis function neural network (RBFNN), support vector regression (SVR), and multivariate adaptive regression splines (MARS), are selected as candidate structural surrogate models. These models are then resampled by bootstrapping and combined to obtain an ensemble model by probabilistic ensemble. Meanwhile, the maximum entropy principal is adopted to search for new design points for sample space updating, yielding a more robust ensemble model. Through the iterations, a framework of surrogate ensemble learning based model updating with high model construction efficiency and accuracy is proposed. The specificities of the method are discussed and investigated in a case study.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.530-533
• /
• 2010

This paper presents numerical analysis and design optimization of various turbine blade cooling techniques with three-dimensional Reynolds-averaged Navier-Stokes(RANS) analysis. The fluid flow and heat transfer have been performed using ANSYS-CFX 11.0. A fan-shaped hole for film-cooling has been carried out to improve film-cooling effectiveness with the radial basis neural network method. The injection angle of hole, lateral expansion angle of hole and ratio of length-to-diameter of the hole are chosen as design variables and spatially averaged film-cooling effectiveness is considered as an objective function which is to be maximized. The impingement jet cooling has been performed to investigate heat transfer characteristic with geometry variables. Distance between jet nozzle exit and impingement plate, inclination of nozzle and aspect ratio of nozzle hole are considered as geometry variables. The area averaged Nusselt number is evaluated each geometry variables. A rotating rectangular channel with staggered array pin-fins has been investigated to increase heat transfer performance ad to decrease friction loss using KRG modeling. Two non-dimensional variables, the ratio of the eight diameter of the pin-fins and ratio of the spacing between the pin-fins to diameter of the pin-fins selected as design variables. A rotating rectangular channel with staggered dimples on opposite walls are formulated numerically to enhance heat transfer performance. The ratio of the dimple depth and dimple diameter are selected as geometry variables.

• 고려인삼학회:학술대회논문집
• /
• 고려인삼학회 1998년도 Advances in Ginseng Research - Proceedings of the 7th International Symposium on Ginseng -
• /
• pp.190-198
• /
• 1998

1 . Experimental study Preventive effect of Korea Red Ginseng (KPG) on hypertensive retinal arteriolosis in rabbits was studied. The results as follows: Blood pressure: Hypertensive group (B) was obviously raised up in comparing with that in normal group(A) and in hypertension + KRG group(C). Ocular fundus:Changes in B group including the retinal arteriospasm, crossing arterioveous, exudation and edema. But C group showed lightly. Light microscope: HE stained vascular damage in retina including thickness hyalimisation, execdates and edema Electron microscope: The endothelial cells were arranged irregularly, different shape and showed cytoplasm loose and vacuole. Immunohistochemistry: Ginseng can regulating endothelin-1, angiotension-ll, endothelium grow factor expre,j,iion and secreation in retinal blood clrultion. 2. ClinicAl Study 66 of hypertensive patients (42 men, 23 women,48-68 years old)and 20 normal person (7 men, 13 women,47-68 years old) were administrated(p.0.) by HRG (3g per day for 6 weeks). The results showed that marked effective rate and total effective rate were 53cyo and 60.6alo respectively and no severe side effects were found. The above results suggest that Ginseng have a difinite hypotensive effect and a role of preventing hyperfine sloe arteriosclerosis.