• Computers and Concrete
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• v.25 no.5
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• pp.411-425
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• 2020

In this paper, the shell material has been taken as functionally graded material and their material quantity is located by the exponential volume fraction law. Moreover, the impact of ring supports around the shell circumference has been examined for their various positions along the shell axial length. These rings support restraints the radial displacement in the transverse direction. While the axial modal deformation functions have been estimated by characteristic beam functions and nature of materials used for construction of cylindrical shells. The fundamental natural frequency of cylindrical shell of parameter versus ratios of length- and height-to-radius for a wide range has been reported and investigated through the study. In addition, by increasing height-to-radius ratio resulting frequencies also increase and frequencies decrease on ratio of length-to-radius. Though the trends of frequency values of both ratios are converse to each other with three different boundary conditions. Also it is examined the position of ring supports with length-to radius ratio, height-to-radius ratio and varying the exponent of volume fraction. MATLAB software package has been utilized for extracting shell frequency spectra. The obtained results are confirmed by comparing with available literature.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.1
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• pp.135-145
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• 1996

Order of stress singularities at bonded Edge Corners with two or three dissimilar isotropic Materials is analyzed. The problem is formulated by Mellin transform and characteristic equation is obtained as a determinant of matrix considering boundary conditions. Roots of characterictic equation are determinde by numerical calculations with ward method, from which the order of stress sigularities is obtained. Applying the results to the electronic packaging, the order of stress singularities is obtained. Applying the results to the electronic packaging, the order of stress singularities at bounded edge corners is calculated as a various bouned edge angle with given material combinations. Comparing the results, the optimal material combinaitons of bounded edge corners and bouned edge angle to reduce stress singularity could be determined. It suggests that the results are used to the basic design of electronic packaging reducing the stress singularity.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.435-435
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• 2011

The electronic structure and various physical properties of CeO2, Ce2O3, PrO2, and Pr2O3 have been studied from the framework of Ab-initio by the all-electron projector-augmented-wave (PAW) method, as implemented VASP (Vienna Ab-initio Simulation Package). The generalized gradient approximation (GGA) with effective U (Ueff) has been used to explain the strong on-site Coulomb repulsion among the localized Ce 4f electrons. The dependence of selected observables of these materials on the Ueff parameter has been scrutinized. The studied properties contain lattice constants, density of states, and reaction energies of CeO2, Ce2O3, PrO2, and Pr2O3. For CeO2 and PrO2, the GGA(PBE)+U results are in good agreement with experimental data whereas for the computational calculationally more demanding Ce2O3 and Pr2O3 both approaches give comparable accuracy. This results represent that by choosing an appropriate Ueff it is possible to reliably describe structural and electronic properties of CeO2, Ce2O3, PrO2, and Pr2O3, which enables modeling of oxygen reduction reaction processes involving ceria-based materials.

• Korean Journal of Materials Research
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• v.4 no.3
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• pp.334-338
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• 1994

This report details the microscopic aspects of grain boundary cracking in Pb-Sn eutecticduring displacement-controlled mechanical tests performed over a range of low frequency ($10^{-3}-10^{-5}$/s)and moderate strain range (0.2 - 1 %) where is the most technologically relevant to solder jointssubjected to thermal cycling. It is shown that intergranular cracking begins with the appearance ofcrack-like features (CLF's), which can be seen due in part because they are associated with grainboundary sliding, and is able to be described by certain stages of isolated crack growth. In the initialstages CLF's are not ture cracks but instead what I shall call "proto-cracks" where grain boundarysliding begins to damage the gram boundary at the surface. At some point during the initiation stagesonce proto-cracks become ture cracks, they develop into isolated cracks and the growth of isolatedcracks is eventually accomplished by coalescence, resulting in 5 stages of cracking.ing in 5 stages of cracking.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.2
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• pp.29-36
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• 2007

This study was concerned about mobile web-service of a VMI in the SCM system. The VMI would be a main module part of the SCM and regarded as very important thing on supply chain. Therefore, it was essential to react in real time of materials production and situation of used auto-part in procurement company. We could find an affordable method to realize the VMI in a web service. The web service has made inter relevant enterprise easy to collaborate because of supporting most operating system and frame-work. Moreover, the use of a mobile tools was guaranteed a product recording and requirement of materials to real time in a rapid changing of production environments. The result of this research was very useful to apply the VMI system in medium and small sized auto parts company. This web service package has programmed the Visual Studio Dot Net 2003 and the MS SQL 2000 as database.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.3
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• pp.458-469
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• 1997

This study was to compare the tensile bond strength and flexibility of four different soft liners(Coe-Soft, Soft Relining, Soft-Liner, Dura Base Soft) before & after thermocycling. Each soft liner was bonded to denture base resin block, and measured the tensile bond strength and modulus of elasticity using Universal testing machine. The mean value of tensile bond strength and modulus of elasticity for each experimental groups were statistically processed by SPSS(Statistical Package of Social Science). The obtained results were as follows : 1. Dura Base Soft had the highest tensile bond strength and Coe-Soft had the lowest tensile bond strength. 2. Coe-Soft had the lowest modulus of elasticity, and Dura Base Soft had the highest modulus of elasticity. 3. Thermocycling had no effects on the tensile bond strength and modulus of elasticity of all the soft liners. 4. The failure modes of Coe-Soft, Soft Relining, Soft Liner were mainly cohesive failure, and that of Dura Base Soft were mainly adhesive failure.

• Korean Institute of Interior Design Journal
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• v.17 no.3
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• pp.94-101
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• 2008

The purpose of this study was to analyze the preference of living room furniture and to suggest Korean brand furniture design guideline. Subjects consisted of 171 residents aged up 20 years old in Seoul and Kyung-ki. area. The data were analyzed using the SPSS statistical package. The results of descriptive statistics, factor analysis, t-test and $x^2$-test are presented. The result of this study showed as fallows; 1) Livingroom funiture design with considering family life behavior were needed. 2) Modernizing traditional elements(motives and pattern) were preferred to duplicating traditional elements. 3) In furniture materials, easy to maintaining and cleaning and environmentally-sound materials as solid wood were highly appraised. Also, functional and harmonious furniture design with interior or other furniture were needed. So, modular-system furniture for livingroom would fulfill user's needs which are function, harmony and conciseness. 4) Elegant, easy, unique, functional, and simple design for livingroom were highly appraised. Considering these results, it is necessary to develop more on the modernized traditional furniture based on the various needs of users. These results provide a practical guideline for the development of the Korean brand design for livingroom furniture design.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.345-345
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• 2007

ZnS/$Na_3AlF_6$/ZnS/Cu multi-layered thin film were simulated by EMP. EMP is a comprehensive software package for the design and analysis of optical thin film. ZnS and $Na_3AlF_6$ was selected as a high refractive index material and low refractive index material And Cu was selected as mid reflective material. Optical properties including color effect were systematically studied in terms of different low refractive index materials thickness. $Na_3AlF_6$ were changed 0.25, 0.5, 0.75, $1.0{\lambda}$. The thin film showed $0.25{\lambda}$ : blue, purple / $0.5{\lambda}$ : yellow $0.75{\lambda}$ : blue, purple, red / $1.0{\lambda}$ : yellow, green, blue, purple. It was becaused by different optical thickness of $Na_3AlF_6$. The maximum of optical interference by refractive layer.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.2
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• pp.255-269
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• 2023

Compared to operational wastes, nuclear power plant (NPP) decommissioning wastes are generated in larger quantities within a short time and include diverse types with a wider range of radiation characteristics. Currently used 200 L drums and IP-2 type transport containers are inefficient and restrictive in packaging and transporting decommissioning wastes. Therefore, new packaging and transport containers with greater size, loading weight, and shielding performance have been developed. When transporting radioactive materials, radiological safety should be assessed by reflecting parameters such as the type and quantity of the package, transport route, and transport environment. Thus far, safety evaluations of radioactive waste transport have mainly targeted operational wastes, that have less radioactivity and a smaller amount per transport than decommissioning wastes. Therefore, in this study, the possible radiation effects during the transport from NPP to disposal facilities were evaluated to reflect the characteristics of the newly developed containers and decommissioning wastes. According to the evaluation results, the exposure dose to transport workers, handling workers, and the public was lower than the domestic regulatory limit. In addition, all exposure dose results were confirmed, through sensitivity analysis, to satisfy the evaluation criteria even under circumstances when radioactive materials were released 100% from the container.

• Journal of environmental and Sanitary engineering
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• v.20 no.2 s.56
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• pp.39-46
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• 2005

This study was Performed to survey and evaluate the contents of Plasticizers such as DEP(diethyl phthalate), DPrP(di-n-Phthalate), DBP(di-n-butyl Phthalate), DPP(di-n-pentyl Phthalate), DCHP(dicyclohexyl phthalate), BBP (butylbenzyl phthalate), DEHP(di-(2-ethylhexyl) phthalate) and DEHA(di-(2-ethylheryl) adipate), which are suspected as endocrine disruptors, in food and drug PVC packaging. Tested samples were 5 food wraps, 35 food containers, 40 food and drug packages(type of tablet and capsule) in Gyeonggi-Do area. The contents of DEHA in wrap were 188.9g/kg, 203.1g/kg, 238.4g/kg, 290.9g/kg and 308.3g/kg, respectively, while the other plasticizers were not detected. DEHP was used in 4 samples of food containers and DEHP contents were 4.7g/kg, 30.7g/kg, 35.8g/kg and 53.4g/kg, respectively. In food and drug packaging materials(type of tablet and capsule), the plasticizers were not detected.