• Journal of The Korean Association For Science Education
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• v.13 no.2
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• pp.210-218
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• 1993

Scientific literacy for all became a new goal and introducing STS issues into science curriculum shows new trends in science education. The educational importance of natural environment of a region is increasing because it can serve as a vehicle to meet the new goal and trends of science education. The opportunity to learn about Korean natural environment in schools was investigated. The characteristics and unique patterns of Korean natural environment are not well reflected in the intended curriculum. School teachers mostly believe that education of Korean natural environment will greatly contribute to the students' learning of the subject matter they teach and environmental problems. However, they have limited opportunity to teach Korean natural environment. Various elective courses dealing with our natural environment should be provided in schools, especially for non-science majors. Out-of-school activities and facilities for Korean natural environment should be made available.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.451-453
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• 1996

There is a question, 'Which is beautiful, a flower or a star?'. Its answer is different from one person .to another. It is only a matter of what one is interested in. It is very difficult for most school pupils, who will have non-scientific jobs, to understand science courses taught currently in school, because each science (physics, chemistry, biology, and earth science) is independently taught from the other sciences. Therefore, their knowledge of sciences obtained during their school period does not significantly help their understanding of global environmental problems. I am proposing that several scientific stories should be prepared to connect all the related scientific phenomena in order to give those pupils ideas in understanding global environmental problems. I believe that astronomy is able to play an important role in this context.

• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.261-266
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• 2009

The angular dispersion-type non-scanning Fabry-Perot was applied to an ethanol-water mixture in order to investigate its acoustic properties such as the sound velocity and the absorption coefficient. The scattered light from the mixture was analyzed by using the charge-coupled-device area detector, which made the measurement time much shorter than that obtained by using the conventional scanning tandem multi-pass Fabry-Perot interferometer. The sound velocity showed a deviation from ultrasonic sound velocities at low temperatures accompanied by the increase in the absorption coefficient, indicating acoustic dispersion due to the coupling between the acoustic waves and some relaxation process. Based on a simplified viscoelastic theory, the temperature dependence of the relaxation time was obtained. The addition of water molecules to ethanol reduced the relaxation time, consistent with dielectric measurements. The present study showed that the angular dispersion-type Fabry-Perot interferometer combined with an area detector could be a very powerful tool in the real-time monitoring of the acoustic properties of condensed matter.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.6
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• pp.805-813
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• 2013

In this study, molecular size distribution of natural organic matter (NOM) after ozonation was measured and its effect on adsorption capacity of activated carbon was investigated. According to the results, the molecular size of NOM was limitedly changed. Specifically, the molecular size of NOM between 5,000 to 10,000 Da were slightly decreased with increasing ozone doses. The adsorption capacity after ozonation was evaluated using Freundlich isotherm with ideal adsorbed solution theory (IAST) which simulated the multi components adsorption. Further, mini-column test was conducted. The Freundlich constant, K was reduced after ozonation and the non-adsorbable fraction was increased with ozonation. However, no correlation between K and ozone doses was found. The present study also agreed with the correlation between adsorption capacity and pore size characteristics of activated carbon.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.700-703
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• 2003

The test method of ASTM E 756 and KS D 0076 to estimate vibration-damping properties is compared. Comparison method depending on specimen support, exciting method and calculation method for loss factor is used. Half-power bandwidth method and vibration decay method is used in the calculation method for loss factor, and Young's modulus is decided by geometric character and density for specimen and resonance frequency. Vibration measurement sensor is compared by using non-contact displacement detector, velocity detector and accelerometer. This paper is also presented the matter which is able to cause error in the measurement

• Korean Journal of Veterinary Pathology
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• v.3 no.2
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• pp.73-76
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• 1999

The tissue distribution and cellular localization of viral antigen in the brain of aborted fetus with bovine viral diarrhea virus(BVDV) infection was studied; BVDV antigens was detected in spleen, kidney, lung, eyelid as well as brain. In the brain, the virus was recognized in neurons and non-neuronal cells in the cerebellum and cerebrum. Many cells in the superficial layer and occasional Purkinje cells had BVDV antigens. As well, BVDV was also found in the perivascular cells, vascular endothelial cells and smooth muscle cells in the vessels and neuroglial cells in the white matter. This finding suggests that BVD virus favors infect progenitor cells in the brain, notably in the superficial layer of cerebellum, and damage normal development of cerebellum, which leads to cerebellar hypoplasia.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.673-677
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• 2002

Cellular-phone payment system is a new innovating technology emerged in Korea since fool. Previous studies concerning the electronic payment system are usually about the payment process itself, so they focused on the matter such as security or the robustness of the process. The study from the angle of behavioral science seldom exists. This article Identifies which characteristic of the cellular-phone payment service affects to the user status (user, non-users). To do this, we used perceptual 4 characteristics in Roger's Technology Acceptance Model with one additional characteristic-security.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.24.4-25
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• 2009

We have investigated the radiational fields through a hydrodynamical stellar model atmosphere. Stellar convection zone is the extremely turbulent region composed of partly ionized compressible gases in high temperature. Moreover, super-adiabatic layers are the transition region in energy transport from convection to radiation. Therefore, opacities and thermodynamic properties due to interaction of matter and radiational fields vary significantly with depth. In order to describe radiational fields accurately, the Opacity Distribution Function (ODF) and the Accelerated Lambda Iteration (ALI) have been applied to hydrodynamic medium. As the first result of our radiative transfer, we present time-dependant variation of radiational fields and thermodynamic structures. Our non-gray transfer model has been compared with the conventional Eddington Approximation. Detailed information of radiational fields and thermodynamic properties will provide deeper insight of physical processes inside stellar atmospheres.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.87-88
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• 2011

High absorptance of lightweight aggregate make a hard product, work, quality management ect. for making low absorptance property, lightweight aggregate is coated by an organic matter and that way remarkably showed to decrease the absorptance by pre-study. but first, we would need a check to fit into the concrete which both fresh concrete and hardened concrete. In this study, mechanical property change of coated lightweight aggregate concrete was analysed by compared experiment with coated lightweight aggregate concrete and non-coated aggregate concrete.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.1
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• pp.24-35
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• 2013

A cell formation approach based on cluster analysis is developed for the configuration of manufacturing cells. Cell formation, which is to group machines and parts into machine cells and the associated part families, is implemented to add the flexibility and efficiency to manufacturing systems. In order to develop an efficient clustering procedure, this paper proposes a cluster analysis-based approach developed by incorporating and modifying two cluster analysis methods, a hierarchical clustering and a non-hierarchical clustering method. The objective of the proposed approach is to minimize intercellular movements and maximize the machine utilization within clusters. The proposed approach is tested on the cell formation problems and is compared with other well-known methodologies available in the literature. The result shows that the proposed approach is efficient enough to yield a good quality solution no matter what the difficulty of data sets is, ill or well-structured.