• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.3
• /
• pp.129-134
• /
• 2004

To analyze the performance of the gas circuit breaker(GCB), the flow field variables such as temperature, pressure and density should be evaluated accurately In the puffer chamber of puffer type GCB, the pressure rise may Exceed 20 bar and in this range of high pressure, $SF_6$ gas deviates the ideal gas property. Therefore, the real gas property of $SF_6$ should be taken into consideration for the accurate analysis of flow field. This paper presents the analysis technique of cold gas flow in GCB employing the real gas state equation of SF6. The FVFLIC method is Employed to solve the axisymmetric Euler equation. To reduce the computational effort of real gas state equation, the relationship between density and pressure is approximated by the polynomial at the temperature of 300K. The proposed method is applied to the test GCB model and simulation results show good agreement with the experimental ones.

• Korean Journal of Human Ecology
• /
• v.14 no.5
• /
• pp.821-832
• /
• 2005

The purpose of this study is to investigate bathing habits and behaviors, and to find out consumers' needs for washcloth, which in this case refers to Korean exfoliating cloth for bathing purpose. Subjects of this study were females of 20s to 50s living in urban area. Four hundred and twenty-six (426) women were interviewed with a structured questionnaire. Data were analyzed by ANOVA, factor analysis, correlation analysis, MDS. The results of this study are briefly summarized as follows: The most popular bathing type was shower (84.9%). Personal hygiene was one of the commonest purpose of bathing, and other purposes included health maintenance, stress alleviation, and beauty in order. Dimensions of consumer needs for washcloth were extracted from factor analysis as following properties: tactile, tough, aesthetic, constructive, and hygienic. The preference for washcloth type was related to skin type. "Non-skin damage property" was the most important parameter to choose washcloth and the other parameters included massage effect, tactile property, foaming property, and easy-to-use property.

• Journal of Adhesion and Interface
• /
• v.6 no.4
• /
• pp.12-17
• /
• 2005

Natural fiber/phenolic biocomposites with chopped henequen fibers treated at various levels of electron beam irradiation (EBI) were made by means of a matched-die compression molding method. The interfacial property was explored in terms of interfacial shear strength measured by a single fiber microbonding test. The thermal properties were studied in terms of storage modulus, tan ${\delta}$, thermal expansion and thermal stability measured by dynamic mechanical analysis, thermomechanical analysis and thermogravimetric analysis, respectively. The result showed that the interfacial and thermal properties depend on the treatment level of EBI done to the henequen fiber surfaces. The present result also demonstrates that 10 kGy EBI is most preferable to physically modify the henequen fiber surfaces and then to improve the interfacial property of the biocomposite, supporting earlier results studied with henequen/poly (butylene succinate) and henequen/unsaturated polyester biocomposites.

• The Journal of Engineering Geology
• /
• v.5 no.3
• /
• pp.301-308
• /
• 1995

In this study, a stochastic finite element method is proposed with a view to consider rock property variations in the analysis of structural behavior on underground caverns. Here, the Monte carlo simulation technique, which has been widely used in probabilistic applications in many engineering fields, is applied for the analysis of the effect rock property distribution. Using the newly developed computer program based on the above - mentioned method, the underground opening in biaxial stress field is analyzed considering the effect of material property variation.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.3
• /
• pp.74-79
• /
• 2010

Automotive industries are interested in material development with low weight and recycling. Grommet is made from EPDM at rubber and used as an automotive component. The nonlinear material properties of rubber are important to predict the behaviors of rubber product. This study concerns material property test to achieve stress-strain curve. Curve fitting is carried out to obtain the nonlinear material constant. The nonlinear material constants of rubber are used for the nonlinear finite element analysis. The results of finite element analysis is executed to predict the behavior property of grommet.

• STI Policy Review
• /
• v.4 no.2
• /
• pp.1-18
• /
• 2013

As the value and role of intellectual property increases in our knowledge-based economy, countries around the world have exerted various efforts to secure, utilize, and protect their intellectual property. The present study diagnoses the level of IP infrastructure of major OECD countries and analyzes their characteristics and impact. According to the diagnosis, the US, Switzerland, and Germany form a leading group followed by the mid-level countries of Korea, Ireland, Australia, and France, with Spain and Italy in the bottom group. In contrast to Korea's competitiveness in S&T and R&D infrastructures, its competitiveness in IP infrastructure is lower than the OECD average. This is thought to be due to Korea's IP infrastructure being hastily formed under the influence of international pressures rather than having been gradually built up by internal needs. A TFP analysis of the impact of IP infrastructure on economic growth shows IP infrastructure positively influences economic growth. Though this analysis is limited due to inability to secure sufficient data and indicators, it is a useful guide for understanding the nature and key characteristics of IP infrastructure.

• Journal of Wind Energy
• /
• v.14 no.4
• /
• pp.43-49
• /
• 2023

We have studied biofouling in Korea's offshore wind farms by using image analysis through monitoring and surface energy analysis. To observe the biofouling characteristics, samples were fabricated using Micron extra 2 and PropOne, which have a self-polishing property, and Hempathane HS 55610, which is used in substructure coatings. The manufactured samples were installed at the bottom of a ladder in a substructure, and monitored for 10 months. The most biofouling occurred in the sample without the self-polishing property, and algae, barnacles and corallinales were observed. The surface energy analysis used the Owens-Wendt-Rabel and Kaelble (OWRK) model, which uses the contact angles of two standard fluids. As a result of calculating the surface energy using contact angle measurement, the sample without the self-polishing property showed the highest value. This result was consistent with the biofouling incidence observed through monitoring.

• Progress in Superconductivity and Cryogenics
• /
• v.20 no.1
• /
• pp.1-10
• /
• 2018

The improvement of critical current properties of $REBa_2Cu_3O_{7-x}$ (REBCO) coated conductors by introducing artificial pinning centers (APCs) is examined with respect to the field-angle anisotropy, high-field performance and relaxation property with time. Nano-rods along the c-axis introduced by PLD method and isotropic nano-particles introduced by TFA-MOD method are treated. The theoretical analysis is also shown to understand the effect of APCs quantitatively. The effects of superconducting layer thickness that influences the high-field performance and relaxation property are also discussed. It is shown that the upper critical field, which is another important factor to determine the high-field property, can be improved by introduction of APCs through electron scattering at interfaces with the superconducting matrix. The optimum critical current property can be obtained by properly designing the morphology and number density of APCs and the superconducting layer thickness.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.1190-1193
• /
• 2004

The purpose of this study is to evaluate the possibility of identifying joint damping property through commercially available isokinetic ergometer (BIODEX). The proposed method is to estimate the damping torque of the knee joint from the difference between the external joint torque for maintaining isokinetic movement and the gravity torque of the lower leg. The damping torque was estimated at various joint angular velocities, from which the damping property would be derived. Measurement setup was composed of the BIODEX system with an external force sensor and Labview system. Matlab was used in the analysis of the damping property. The experimental result showed that the small variation in angular velocity due to acceleration and deceleration of the crank arm resulted in greater change of inertial torque than the damping torque, so that the estimation of damping property from the isokinetic movement is difficult.

• Journal of the Korea Furniture Society
• /
• v.26 no.4
• /
• pp.398-408
• /
• 2015

Though the physical environment of life through technological evolution has rapidly improved, the quality of life due to a variety of undesirable environmental issues has been seriously damaging. This study has tried to suggest the positive & sustainable direction of space design which can contribute to improving the quality of human lives by reviving 'place property' which a site itself has, trying to analyze the recycling space which the sustainability has been applied to in a true sense. For this cause, we've tried to draw four 'methods of realizing place property' such as meeting a site, understanding a site, finding the identity of a site, and adding novelty to a site through advanced research. I've tried to suggest the design direction for reviving space which can relieve the artificial aspect of design with pursuing the co-existence with nature on the foundation of realizing 'place property' through case analysis selected on the basis of this, and can express the 'sustainability' through environment-friendly space structures & high efficiency of its function.