• Magazine of the Korean Society of Agricultural Engineers
• /
• v.34 no.1
• /
• pp.66-77
• /
• 1992

A prototype probabilistic approach to thickness design for asphalt pavement surface course was developed using first-order second moment probability model. The tensile strain (load effect) developing at the bottom of surface layer due to the wheel load and the critical strain (resistance) of asphalt concrete were used as random variables for pavement reliability analysis. Based on the parameters for load effect and resistance data collected from reference and field, simulated data were generated by Monte Carlo method for reliability evaluation of the pavement for a typical rural highway. Thickness of pavement surface course was defined in terms of target reliability of the pavement, growth factor of traffic, design life of pavement and resistance of the asphalt concrete to be placed on the pavement. According to these rationales, prototype thickness design chrats were sugested through example studies. From these, similar design charts can be developed for many pavements if appropriate data and target reliability are determined.

• Proceedings of the KIEE Conference
• /
• 1998.07e
• /
• pp.1617-1619
• /
• 1998

In the nation, 154kV XLPE cable with an insulation thickness of 23mm have been used for transmission lines. The thickness is designed by old parameters which were determined by Kreuger, Oudin et al. in 1960s. By the way, the manufacturing technology has been developed. Especially in extruding and curing process we are using a triple common extruding head and applying gas-curing process. It allows the quality of XLPE cable improved. The paper evaluates the AC minimum insulation breakdown strength of XLPE power cable using model table. We can verify the uplifted insulation quality. And we expects the cable insulation thickness to be reduced applying the new parameter to the cable insulation design.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2006.03a
• /
• pp.89-96
• /
• 2006

Recently, many researches on the dissipation of excess pore pressure in liquefied sand grounds have been performed to evaluate post-liquefaction behaviors of structures. In this paper. centrifuge tests were performed to simulate liquefaction behaviors of prototype soil. The evaluation model of solidified layer thickness was developed to simulate non-linear variation of solidified layer thickness with time. Also, the dissipation of excess pore pressure in liquefied sand was evaluated by applying the solidification theory and the consolidation theory. The developed model gives a good estimation of the solidified layer thickness and the time history of excess pore pressure.

• Steel and Composite Structures
• /
• v.11 no.3
• /
• pp.183-205
• /
• 2011

This paper presents the results of an investigation into the post-buckling behaviour and ultimate strength of imperfect corroded steel plates used in ship and other marine-related structures. A series of elastic-plastic large deflection finite element analyses is performed on randomly corroded steel plates. The effects of general corrosion on both sides of the plates are introduced into the finite element models using a random thickness surface model. The effects on plate compressive strength as a result of parametric variation of the corroded surface geometry are evaluated. A proposal on the effective thickness is concluded in order to estimate the ultimate strength and explore the post-buckling behaviour of randomly corroded steel plates under uniaxial compression.

• Journal of radiological science and technology
• /
• v.43 no.6
• /
• pp.469-473
• /
• 2020

Breast cancer is growing rapidly year by year and has the highest incidence since 2001. As a result, the interest in mammography for early detection of breast cancer is increasing. However, mammography is accompanied by radiation exposure and therefore it is necessary to reduce exposure dose through appropriate test conditions. The significance of this study is that breast dose studies, which were limited to ordinary women, were applied to breast implant patient. Using MCNP simulation, the phantom with prosthesis inserted was developed to compare dose by tube voltage by pressure thickness. In addition phantom without prostheses has higher dose than phantom with prostheses. If these results were used as basic data, it would be possible to recommend test condition guideline only for breast implant patients.

• Design & Manufacturing
• /
• v.17 no.3
• /
• pp.61-66
• /
• 2023

In this study, we developed a simulation methodology for a technology that rapidly cools molds by directly spraying them with CO₂ in its liquefied gaseous state. Initially, a simulation verification process was conducted using ANSYS Fluent's heat transfer analysis based on temperature values measured in prior research experiments, ensuring a comparable temperature could be calculated. Subsequently, the validated analysis method was employed to evaluate design factors that exert the most significant influence on cooling. An evaluation was conducted based on three factors: part thickness, mold thickness, and the melting temperature of material. Using a full factorial design approach, a total of 27 analyses were completed and subsequently calculated through analysis of means. The impact assessment was carried out based on the temperature values at the product's core. The results indicated that the thickness of the mold had the highest influence, while the melting temperature of material had the least.

• Journal of Animal Science and Technology
• /
• v.44 no.4
• /
• pp.377-382
• /
• 2002

This study was carried out for the simultaneous genetic evaluation of swine breeds from the seedstock farms in Korea. The performance tested production records of 96,842 heads and the litter records of 90,396 litters from 1995 to 2001 were analyzed to estimate the breeding values and the breed effects of days to 90kg, daily gain, back fat thickness, loin muscle area, lean meat percent, total litter size and number born alive from Landrace, Yorkshire and Duroc. Estimated breed effects of traits had shown the characteristics of the breeds. Landrace was superior in back fat thickness and lean meat percent to other breeds. Yorkshire had shown good performance in lean meat percent, loin muscle area, total litter size and number born alive. Duroc was superior to the other breeds in days to 90kg and daily gain. Conclusively, the multi-breed genetic evaluation would result in higher connectedness and provide convenience for the routine genetic evaluation process of swine performance and reproduction test.

• Journal of the Society of Naval Architects of Korea
• /
• v.38 no.1
• /
• pp.72-85
• /
• 2001

A study for the structural strength evaluation on the doubler plate subjected to the biaxial in-plane compression has been performed through the systematic evaluation process. In order to estimate the proper static strength of doubler plate, elasto-plastic large deflection analysis is introduced including the contact effect between main plate and doubler. The characteristics of stiffness and strength variation are discussed based on their results. A1so, in order to compare the doubler structure with the original strength of main plate without doubler, a simple formula for the evaluation of the equivalent flat plate thickness is derived based on the additional series analysis of flat plate structure. Using this derived equation, the thickness change of a equivalent flat plate is analyzed according to the variation of various design parameters of doubler plate and some design guides are suggested in order to maintain the original strength of main plate without doubler reinforcement. Finally, correlation between derived equivalent flat plate formula and the developed buckling strength formulas by author et a1. is discovered and these relations are formulated for the future development of simple strength evaluation formula of doubler plate structure.

• Restorative Dentistry and Endodontics
• /
• v.41 no.3
• /
• pp.159-166
• /
• 2016

The purpose of this review was to suggest practical criteria for the clinical translucency evaluation of direct esthetic restorative materials, and to review the translucency with these criteria. For the evaluation of reported translucency values, measuring instrument and method, specimen thickness, background color, and illumination should be scrutinized. Translucency parameter (TP) of 15 to 19 could be regarded as the translucency of 1 mm thick human enamel. Visual perceptibility threshold for translucency difference in contrast ratio (${\Delta}CR$) of 0.07 could be transformed into ${\Delta}TP$ value of 2. Translucency differences between direct and indirect resin composites were perceivable (${\Delta}TP>2$). Universal and corresponding flowable resin composites did not show perceivable translucency differences in most products. Translucency differed significantly by the product within each shade group, and by the shade group within each product. Translucency of human enamel and perceptibility threshold for translucency difference may be used as criteria for the clinical evaluation of translucency of esthetic restorative materials.

• Journal of radiological science and technology
• /
• v.41 no.2
• /
• pp.115-122
• /
• 2018

We aims to perform comparative analysis on the dose area and image qualities varying on the slice thickness when using Automatic Exposure Controller (AEC) and manual exposure; thus, it wants to suggest a measure to reduce exposure dose by setting the optimal examination condition for each slice thickness. The method was to set the thickness as Thin, Normal, and Heavy adult and evaluate the dose area, spatial resolution, low contrast resolution, Signal to Noise Ratio (SNR) and Contrast to Noise Ratio (CNR) according to each slice thickness by using the AEC and the manual exposure controller. The dose area according to each slice thickness all increased both when using the AEC and the manual exposure. However, the manual exposure showed lower dose area product than the AEC. Spatial resolutions and low contrast resolutions were all observed to be higher than the evaluation standard. Also, the SNR and CNR of each thickness all increased when using the AEC. When using the manual exposure, SNR and CNR increased in all cases other than the Heavy Adult. Consequently, the Thin and Normal Adult showed dose reduction about 2 times when using the manual exposure controller, while ensuring the image quality. Heavy adult was able to maintain good image quality by using AEC.