• Journal of Ginseng Research
• /
• v.9 no.2
• /
• pp.204-212
• /
• 1985

Lipid and fatty acid compositions of the bound lipids in Panax quinquefolium (Korea, Japan and China), Panax quinquefolium (America, Canada) and Panax notoginseng (China) were studied by means of silicic acid column chromatography, thin-layer chromatography and gas-liquid chromatography. The could lipid contents in various ginsengs were 0.29 to 0.48%, in which neutral lipid fractions were 63.6 to 67.3%, glycolipid fractions 21.9 to 25.7% and phospholipid fractions 7.7 to 12.4%. The content compositions of neutral lipid fractions were lower and those of glycolipid and phospholipid fractions were higher in the bound lipids than in the free lipids from the various ginseng. The major components were fatty acids, diglycerides and free sterols in neutral lipid fractions, monogalactosyl diglyceride, sterol glucoside and esterified steryl g1ycoside in glycolipid fractions and phosphatidyl glycerol, phosphatidyl ethanolamine and phosphatidic acid in phosphoipid fractions. Seventeen fatty acids were analyzed in the four bound lipid fractions from the various ginsengs and main fatty acids were linoleic acid, palmitic acid and oleic acid. Total saturated fatty acid and palmitic acid contents were higher and total unsaturated fatty acid and linoleic acid contents lower in the total bound lipids than in the total free lipids from the various ginsengs.

• Transactions of Materials Processing
• /
• v.12 no.6
• /
• pp.588-596
• /
• 2003

The relationships between evolution of microstructure and mechanical properties of porous Al-3Si-2Mg-2Cu alloy after the foaming and various heat treating were investigated. The foamed alloy having various densities were manufactured by powder compact foaming and heat treated. Then compression test was performed with deformation rate of 0.5/s. The ultimate compression strength was not changed after solution heat treatment but the flow curve after ultimate strength showed very smooth and uniform plateau region. This change of flow curve means that the deformation mechanism is altered from brittle fracture to ductile deformation and the energy absorption property of Al foam is dramatically improved. The improvement of energy absorption without any detriment of mechanical properties is due to that the very brittle precipitation like Al-Cu and Al-Mg was uniformly dissolved in Al matrix after solution heat treatment. And various mechanical properties of Al alloy porous material were improved by 40% with aging of $200^{\circ}C$ and 50min. These improvements are ascribe to the various fine precipitates like $\Omega$ and $\theta$'.

• Journal of Mechanical Science and Technology
• /
• v.19 no.8
• /
• pp.1662-1669
• /
• 2005

Boiling heat transfer characteristics of a two-phase closed thermosyphons with various helical grooves are studied experimentally and a mathematical correlation is developed to predict the performance of such thermosyphons. The study focuses on the boiling heat transfer characteristics of two-phase closed thermosyphons with copper tubes having 50, 60, 70, 80, 90 internal helical grooves. A two-phase closed thermosyphon with plain copper tube having the same inner and outer diameter as those of grooved tubes is also tested for comparison. Water, methanol and ethanol are used as working fluid. The effects of the number of grooves, various working fluids, operating temperature and heat flux are investigated experimentally. From these experimental results, a mathematical model is developed. In the present model, boiling of liquid pool in the evaporator is considered for the heat transfer mechanism of the thermosyphons. And also the effects of the number of grooves, the various working fluids, the operating temperature and the heat flux are brought into consideration. A good agreement between the boiling heat transfer coefficient of the thermosyphon estimated from experimental results and the predictions from the present mathematical correlation is obtained. The experimental results show that the number of grooves, the amount of the working fluid and the various working fluids are very important factors for the operation of thermosyphons. Also, the thermosyphons with internal helical grooves can be used to achieve some inexpensive and compact heat exchangers in low temperature.

• Progress in Superconductivity and Cryogenics
• /
• v.16 no.1
• /
• pp.27-31
• /
• 2014

2G HTS tapes are widely used for various electric machines. In addition, stacked or parallel connected HTS tapes are essentially used to raise transport current level for large capacity electric machines. Therefore, critical current characteristic of stacked tapes need to be studied. Recently developed 2G HTS tapes are fabricated with various defects doping so that tapes possess pinning center to improve the critical current characteristic. During this process, the critical current is determined minimum value in not perpendicular magnetic field but a specific magnetic field angle according to the reported research. However, the effects of magnetic field angle to critical current of multi-stacked 2G HTS tapes have not been examined. In this paper, field coil which is a race-track coil wound by using an HTS tape with iron-core was fabricated to apply angle adjustable magnetic field to the 2G HTS tape samples. We measured critical current of single and multi-stacked two tapes that have different characteristic depending on various magnetic field angle and magnitude in liquid nitrogen environment. Furthermore, results of single and multi-stacked tapes were compared and analyzed.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2003.11a
• /
• pp.83-86
• /
• 2003

With the opening of digital broadcast services and development of wire/wireless Internet, the current multimedia broadcasting is provided for has various services. The user will be provided lots of various content through the various channel and media. Content provider and consumer want the various service using content with the better quality which is fit to user preference. For transmitting this content in the limited transmission channel capacity, it needs to transmit the highly compressed content which user wants. The content of 3D mesh model-based on MPEG-4 enables the various content service that provides the lower capacity and the better quality, and Targeting service enables just provide the contents that user more wants and likes. The adaption of Java application program and 3D program can provide the content service utilizing 3D mesh model, so content provider and consumer can share the more information about the content. This paper has presented the study on the targeting service using compression of 3D mesh model-based on MPEG-4 and the adaptation of Java application program using it

• Proceedings of the Korea Water Resources Association Conference
• /
• 2018.05a
• /
• pp.448-448
• /
• 2018

In this study, the regression models (Load ESTimator and eight-parameter model) were evaluated to estimate instantaneous pollutant loads under various criteria and optimization methods. As shown in the results, LOADEST commonly used in interpolating pollutant loads could not necessarily provide the best results with the automatic selected regression model. It is inferred that the various regression models in LOADEST need to be considered to find the best solution based on the characteristics of watersheds applied. The recently developed eight-parameter model integrated with Genetic Algorithm (GA) and Gradient Descent Method (GDM) were also compared with LOADEST indicating that the eight-parameter model performed better than LOADEST, but it showed different behaviors in calibration and validation. The eight-parameter model with GDM could reproduce the nitrogen loads properly outside of calibration period (validation). Furthermore, the accuracy and precision of model estimations were evaluated using various criteria (e.g., $R^2$ and gradient and constant of linear regression line). The results showed higher precisions with the $R^2$ values closed to 1.0 in LOADEST and better accuracy with the constants (in linear regression line) closed to 0.0 in the eight-parameter model with GDM. In hence, based on these finding we recommend that users need to evaluate the regression models under various criteria and calibration methods to provide the more accurate and precise results for pollutant load estimations.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.33 no.5
• /
• pp.282-287
• /
• 2019

In this study, we investigated the anti-obesity effects of various mixtures of Atractylodes macrocephala (AM) and Amomum villosum (AV) water extracts on high-fat diet (HFD) induced mouse model. We classified five groups as follows; control, HFD, HFD + AM extracts : AV extracts (100mg/kg) (1:1), HFD + AM extracts : AV extracts (100mg/kg) (2:1), HFD + AM extracts : AV extracts (100mg/kg) (3:1). Oral administration of various mixtures of AM and AV extracts for 6 weeks inhibited HFD-induced increases of body, liver and epididymal fat weights. Also, lipid profiles including LDL cholesterol were improved by various mixtures of AM and AV extracts treatment compared with HFD-fed group. Lipogenesis-related genes such as acetyl coA carboxylase (ACC) and fatty acid synthase (FAS) in liver changed in a favorable way for lipid biosynthesis by HFD compared to control, but various mixtures of AM and AV extracts-treated groups did not. Our results show that various mixtures of AM and AV extracts can prevent HFD-induced obesity in mice and suggests that the mechanisms are involved in expressions and modifications of lipogenesis-related genes such as ACC and FAS in liver.

• Journal of Fashion Business
• /
• v.25 no.4
• /
• pp.141-150
• /
• 2021

Recently, interest of consumers in home furnishing products has increased steadily because of the increased time spent at home due to COVID-19. Among them, carpets made of various materials and technologies are becoming popular interior item. Academic and industrial sectors agreed on the need to produce premium design carpets. Prior research on carpet design was mostly focused on patterns, history, with insufficient investigations on the type. Therefore, the purpose of this study was to provide basic data to develop premium design carpets by analyzing their expression types. To analyze expression types, this study covered about 400 design carpets surveyed on the websites of eight major carpet companies from January 2021 to March 2021. Based on the analysis results, the five expression types of are as follows. Firstly, the expression type was expressed in various atypical forms that was deviated from the formal form. Secondly, it was a type that improves visual and tactile effects through a variety of 3-D textures. Thirdly, it was a type of diversification of motifs, which was based on the works of artists and designers in various fields. Fourthly, it was a type that combines two or more different materials and techniques. Finally, it was a modular type that can be applied in various ways to various spaces. Based on the analysis results of this study, it is hoped that the data will be helpful to produce premium design carpets in Korea.

• Structural Engineering and Mechanics
• /
• v.71 no.5
• /
• pp.485-502
• /
• 2019

In this research, the nonlinear static, buckling and vibration analysis of viscoelastic micro-composite beam reinforced by various distributions of boron nitrid nanotube (BNNT) with initial geometrical imperfection by modified strain gradient theory (MSGT) using finite element method (FEM) are presented. The various distributions of BNNT are considered as UD, FG-V and FG-X and also, the extended rule of mixture is used to estimate the properties of micro-composite beam. The components of stress are dependent to mechanical, electrical and thermal terms and calculated using piezoelasticity theory. Then, the kinematic equations of micro-composite beam using the displacement fields are obtained. The governing equations of motion are derived using energy method and Hamilton's principle based on MSGT. Then, using FEM, these equations are solved. Finally the effects of different parameters such as initial geometrical imperfection, various distributions of nanotube, damping coefficient, piezoelectric constant, slenderness ratio, Winkler spring constant, Pasternak shear constant, various boundary conditions and three material length scale parameters on the behavior of nonlinear static, buckling and vibration of micro-composite beam are investigated. The results indicate that with an increase in the geometrical imperfection parameter, the stiffness of micro-composite beam increases and thus the non-dimensional nonlinear frequency of the micro structure reduces gradually.

• Smart Structures and Systems
• /
• v.24 no.4
• /
• pp.525-539
• /
• 2019

In this study, vibration characteristics of a gravity-based caisson-foundation breakwater system are investigated for ambient and geometric parameters such as various waves, sea levels, and foundation conditions. To achieve the objective, following approaches are implemented. Firstly, operational modal analysis methods are selected to identify vibration modes from output-only dynamic responses. Secondly, a finite element model of an existing caisson-foundation breakwater system is established by using a structural analysis program, ANSYS. Thirdly, forced vibration analyses are performed on the caisson-foundation system for two types of external forces such as controlled impacts and wave-induced dynamic pressures. For the ideal impact, the wave force is converted to a triangular impulse function. For the wave flow, the wave pressure acting on the system is obtained from wave field analysis. Fourthly, vibration modes of the caisson-foundation system are identified from the forced vibration responses by combined use of the operational modal analysis methods. Finally, vibration characteristics of the caisson-foundation system are investigated under various waves, sea levels, and foundations. Relative effects of foundation conditions on vibration characteristics are distinguished from that induced by waves and sea levels.