• Journal of the Korean Home Economics Association
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• v.47 no.3
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• pp.67-77
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• 2009

This study developed a model economic education program for young children related to Korean seasonal customs. The model was developed via literature reviews and survey research concerning teachers’' recognition of ‘'early childhood economic education’', consultations with professionals in the field, and testing and modifying the program. The goals of the model program were: teaching children to understand basic economic concepts, helping children to develop an economic attitude that emphasizes interdependence, and acknowledging the importance of eco-friendly economic values. The model includes three educational areas and 21 content areas including understanding the concept of exchange, sharing and cooperation, and circulation with nature. This study also developed 37 early childhood economic education activities using the teaching and learning methods of experiencing nature, virtual experience, real life experience, and traditional games experience.

• Korea-Australia Rheology Journal
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• v.15 no.3
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• pp.109-115
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• 2003

Rheometry testing and the DSC measurement of five thermotropic liquid crystalline polymers (TLCP) have been carried out. The dynamic viscosities of the five TLCPs show a typical shear-thinning behaviour obeying the power-law with the power indices from 0.2 to 0.3. When these TLCPs are heated above the melting temperatures determined by the DSC measurements, the dynamic viscosities first rapidly decrease by 2～3 orders of magnitude then level off, finally increase gradually with the further increasing of temperature. The steady shearing exhibited the same behaviour as the dynamic shearing, but serious edge fracture of material slippage out of the plates occurred. The abnormal temperature dependence of the viscosities can be explained by the nematic-isotropic transition. By using the concept of activation energy, we propose a simple model which can fit the shear-thinning behaviour quite well and predict qualitatively correct temperature effects.

• Transactions of Materials Processing
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• v.21 no.3
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• pp.172-178
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• 2012

We performed a shot peening test and used a 2-D finite element model which predicts the compressive residual stress distribution below the material's surface. In this study, the concept of 'impact cycle' is introduced to account for the irregularity in the shot's impact position during testing. The impact cycle was imbedded in the finite element model. In the shot peening test, shot bombarded a type-A Almen strip surface with different impact velocities. To verify the proposed finite element model, we compared the deformed cross sectional shape of the Almen strips with the shapes computed by the proposed finite element model. Good agreement was noted between measurements and the finite element model predictions. With the verified finite element model, a series of finite element simulations was conducted to compute the residual stress distribution below the material's surface and the characteristics of these distributions are discussed.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.51-59
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• 2004

The geological research as a part of HLW disposal program in Korea is carried out to provide necessary data for the establishment of the reference repository system in term of design and safety assessment in the crystalline rock terrains. Six deep boreholes were drilled to obtain hydrogeological and hydrochemical data from Jurassic granites in the Yuseong area, Korea. The core observation, televiewer logging and hydraulic testing were carried out during and after drilling and multi-packer system were installed in the boreholes of 500m depth for hydraulic and hydrochemical monitoring including environmental isotopes. The integration of hydrogeochemical and hydrodynamic data would be built greater confidence for the understanding of groundwater system in fractured rock mass. This geoscientific program could be possible to suggest a general guideline to develop the reference disposal concept of high-level radioactive waste in Korea.

• Structural Engineering and Mechanics
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• v.53 no.3
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• pp.429-442
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• 2015

The measurement from the indentation process depends on the amount of pile-up or sink-in around the contact impressions. In this paper, finite element concept is utilized to study the pile-up and sink-in behaviour for the wide range of materials with different young's modulus, yield stresses, strain-hardening exponents and coefficient of friction values. The exact indentation model is created by using the two dimensional axisymmetrical model for simulating the spherical indentation process on the lines of Taljat and Pharr (2004) work. The result shows that during spherical indentation process the amount of pile-up is greatly influenced by the strain hardening exponents in addition to other material properties and depth of penetration. The numerical results from the finite element analysis are also validated using the exact multilinear material properties obtained from the tensile testing for the materials like mild steel, brass and aluminium.

• Structural Engineering and Mechanics
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• v.59 no.6
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• pp.1071-1094
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• 2016

We employ the so-called problem-dependent linked interpolation concept to develop two cubic 4-node quadrilateral plate finite elements with 12 external degrees of freedom that pass the constant bending patch test for arbitrary node positions of which the second element has five additional internal degrees of freedom to get polynomial completeness of the cubic form. The new elements are compared to the existing linked-interpolation quadratic and nine-node cubic elements presented by the author earlier and to the other elements from literature that use the cubic linked interpolation by testing them on several benchmark examples.

• Journal of Environmental Science International
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• v.14 no.1
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• pp.1-8
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• 2005

CFD code are used for numerically testing a new concept of large space air control system. A workshop with air-conditioners products lines and air-conditioned by several floor type air-containers is tested. The whole room air distribution is controlled by boosters installed in a middle height horizontal plane. First, calculated results are compared with measured data to confirm the validity and applicability of the prediction method. Next, the method is applied to case studies heating seasons. Results under some operating conditions show effectiveness in avoid the temperature stratification in winter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.236-239
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• 2002

The electron-atom collision studies has been essentially use\ulcorner for testing and developing suitable theories of the scattering and collision processes, and for providing a tool for obtaining detailed information on the structure of the target atoms and molecules and final collision products. And, the development of that has also been strongly motivated by the need for electron collision data in such fields as laser physic and development, astrophysics, plasma devices, upper atmospheric processes and radiation physics. Therefore, we explains the concept and the principle of determination of the electron collision cross sections for atoms and molecules by using the present electron swarm method.

• The Magazine of the IEIE
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• v.29 no.3
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• pp.41-48
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• 2002

This paper presents a basic concept of lab-on-a-chip systems and their advantages in chemical and biological analyses. In addition, magnetic bead-based immunoassay on a microfluidic system is also presented as a typical example of lab-on-chip systems. Rapid and low volume immunoassays have been successfully achieved on the demonstrated lab-on-a-chip using magnetic beads, which are used as both immobilization surfaces and bio-molecule carriers. Total time required for an immunoassay was less than 20 minutes including sample incubation time, and sample volume wasted was less than $50{\mu}l$ during five repeated assays. Lab-on-a-chip is becoming a revolutionary tool for many different applications in chemical and biological analysis due to its fascinating advantages (fast and low cost) over conventional chemical or biological laboratories. Furthermore, simplicity of lab-on-a-chip systems will enable self-testing capability for patients or health consumers overcoming space limitation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.494-501
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• 2003

Web casting has become an important opportunity to apply the user-centered concept to broadcasting because it provides real-time interactive service through time and space. It is also necessary to have a new understanding about user who is not a passive viewer any more but an active user. The amount and quality of contents are also important, but usability is a competitive factor as well as the fundamental customer services that have user best experience at the site. Nevertheless most of web casting sites show the low level of usability. In this study we had a comparative evaluation among these sites, MBC, KBS and SBS, which are the representative broadcasting systems. The tests were carried out as heuristic evaluation and usability testing. We analyzed causes and problems of web usability for customer satisfaction and reliability exaltation, and expected the basic knowledge of developing and improving sites.