• 산업경영시스템학회지
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• 제28권3호
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• pp.1-9
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• 2005

We developed the logical methods to analyze economic impacts of standardization and cleared up effects of performing KS in micro and macro aspects. This study is performed through analysing foreign studies and results from surveys. The advanced methods performing standardization as a form of 'Korean industrial standards' are suggested here, which are based on results of this study. The major consequences of this study are followings. The micro economic impact is that each company gets 604.5 millions won a year through performing KS A and F(discount rate 4.5%) and 1.46 trillions won is the macro economic impact through performing total KS A and F, which comes to 0.245% of GDP.

• Structural Engineering and Mechanics
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• 제70권1호
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• pp.1-11
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• 2019

This study deals with a method based on the modified bivariate gamma function for reconstructions of dynamic behavior of delaminated composite plates subjected to impact loads. The proposed bivariate gamma function is associated with micro-genetic algorithms, which is capable of solving inverse problems to determine the stiffness reduction associated with delamination. From computing the unknown parameters, it is possible for the entire dynamic response data to develop a prediction model of the dynamic response through a regression analysis based on the measurement data. The validity of the proposed method was verified by comparing with results employing a higher-order finite element model. Parametric results revealed that the proposed method can reconstruct dynamic responses and the stiffness reduction of delaminated composite plates can be investigated for different measurements and loading locations.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1371-1382
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• 2016

MicroRNAs (miRNAs) are short non-coding RNAs that post-transcriptionally regulate expression of mRNAs in many biological pathways. Liver plays an important role in the feed efficiency of animals and high and low efficient cattle demonstrated different gene expression profiles by microarray. Here we report comprehensive miRNAs profiles by next-gen deep sequencing in Angus cattle divergently selected for residual feed intake (RFI) and identify miRNAs related to feed efficiency in beef cattle. Two microRNA libraries were constructed from pooled RNA extracted from livers of low and high RFI cattle, and sequenced by Illumina genome analyser. In total, 23,628,103 high quality short sequence reads were obtained and more than half of these reads were matched to the bovine genome (UMD 3.1). We identified 305 known bovine miRNAs. Bta-miR-143, bta-miR-30, bta-miR-122, bta-miR-378, and bta-let-7 were the top five most abundant miRNAs families expressed in liver, representing more than 63% of expressed miRNAs. We also identified 52 homologous miRNAs and 10 novel putative bovine-specific miRNAs, based on precursor sequence and the secondary structure and utilizing the miRBase (v. 21). We compared the miRNAs profile between high and low RFI animals and ranked the most differentially expressed bovine known miRNAs. Bovine miR-143 was the most abundant miRNA in the bovine liver and comprised 20% of total expressed mapped miRNAs. The most highly expressed miRNA in liver of mice and humans, miR-122, was the third most abundant in our cattle liver samples. We also identified 10 putative novel bovine-specific miRNA candidates. Differentially expressed miRNAs between high and low RFI cattle were identified with 18 miRNAs being up-regulated and 7 other miRNAs down-regulated in low RFI cattle. Our study has identified comprehensive miRNAs expressed in bovine liver. Some of the expressed miRNAs are novel in cattle. The differentially expressed miRNAs between high and low RFI give some insights into liver miRNAs regulating physiological pathways underlying variation in this measure of feed efficiency in bovines.

• 펄프종이기술
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• 제44권6호
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• pp.79-86
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• 2012

The aim of this general remarks is to introduce the results concerning the thermo physical, charging, developing and fusing characteristics of micro-encapsulated (MC) model toners in order to apply to the toner of electrophotographic system at the condition of a low temperature. In order to clarify the fusing mechanism of MC toner, rheological analysis of the toner was chosen. It was suggested that MC toner had a different fusing mechanism compared with non-MC toner. Some kinds of MC model toners showed a good result on adhesion test as well as cohesion test. Also, it was possible to get the good charging and development characteristic of MC toner for printing test with laser printer.

• Asian Journal of Atmospheric Environment
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• 제10권2호
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• pp.114-123
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• 2016

A change in chemical compositions of Asian dust (AD) particles can dramatically alter their optical properties, cloud-forming properties, and health effects. The present study was undertaken to evaluate this aging of AD particles by means of two complementary methods (i.e., the traditional spot test and the most advanced micro-PIXE analytical technique) for single particle analysis. Size-classified particles were sampled at the rural peninsula of Korea (Byunsan, 35.37N; 126.27E) during AD event and non-AD period in 2004. Sulfate was principally enriched on the particles in the size range of $7.65-10.85{\mu}m$ collected during AD event. The average number fraction of coarse particles ($>2.05{\mu}m$) containing chloride was 16.2% during AD event. Relatively low particles containing nitrate compared to those containing sulfate and chloride were found in AD event. Micro-PIXE elemental maps indicated that a large number of AD particles were internally mixed with man-made zinc. The highest peaks of EC and OC concentrations were appeared at $0.01-0.43{\mu}m$ particle aerodynamic diameter. High EC concentration in $PM_1$ was might be caused by the Saemangeum Seawall Project that was being conducted during our field measurement.

• 콘크리트학회논문집
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• 제17권5호
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• pp.857-868
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• 2005

This paper deals with the accumulated damage in concrete structures due to the cyclic freeze-thaw as an environmental load. The cyclic ice body nucleation and growth processes in porous systems are affected by the thermo-physical and mass transport properties, and gradients of temperature and chemical potentials. Furthermore, the diffusivity of deicing chemicals shows significantly higher value under cyclic freeze-thaw conditions. Consequently, the disintegration of concrete structures is aggravated at marine environments, higher altitudes, and northern areas. However, the properties of cyclic freeze-thaw with crack growth and diffusion of chloride ion effects are hard to be identified in tests, and there has been no analytic model for the combined degradations. The main objective is to determine the driving force and evaluate the reduced strength and stiffness by freeze-thaw. For the development of computational model of those coupled deterioration, micro-pore structure characterization, pore pressure based on the thermodynamic equilibrium, time and temperature dependent super-cooling with or without deicing salts, nonlinear-fracture constitutive relation for the evaluation of internal damage, and the effect of entrained air pores (EA) has been modeled numerically. As a result, the amount of ice volume with temperature dependent surface tensions, freezing pressure and resulting deformations, and cycle and temperature dependent pore volume has been calculated and compared with available test results. The developed computational program can be combined with DuCOM, which can calculate the early aged strength, heat of hydration, micro-pore volume, shrinkage, transportation of free water in concrete. Therefore, the developed model can be applied to evaluate those various practical degradation cases as well.

• Asian Journal of Atmospheric Environment
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• 제5권1호
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• pp.56-63
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• 2011

Quantifying the solute composition of a cloud droplet (or a whole droplet) is an important task for understanding formation processes and heating/cooling rates. In this study, a combination of droplet fixation and SR-XRF microprobe analysis was used to visualize and quantify elements in a micro-scale droplet. In this study, we report the preliminary outcome of this experiment. A spherical micro-scale droplet was successfully solidified through exposure to ${\alpha}$-cyano-acrylate vapor without affecting its size or shape. An X-ray microprobe system equipped at the beam line 37XU of Super Photon ring 8 GeV (SPring-8) was applied to visualize and quantify the elemental composition in an individual micro-scale droplet. It was possible to reconstruct 2D elemental maps for the K and Cl contained in a microdroplet that was dispensed from the 10-ppm KCl standard solution. Multi-elemental peaks corresponding to X-ray energy were also successfully resolved. Further experiments to determine quantitative measures of elemental mass in individual droplets and high-resolution X-ray microtomography (i.e., 3D elemental distribution) are planned for the future.

• 산업경영시스템학회지
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• 제8권12호
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• pp.79-87
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• 1985

Environmental approach places the focus on a cause-and-effect relationship between the external environments and the internal business conditions. But that approach is an attempt to describe the characteristics of environmental constraints. W.J. Abernathy, K.B. Clark, and A.M. Kantrow attribute the Japanese carmaker's success to superiority in the manufacturing plant, especially in their process systems and work force management. They provide a paradigm for discussions of manufacturing competitiveness comparison. The structure of the paradigm has two main distinctions. The first is the division between analysis and prescription of a macro sort and those of a micro sort, the second is the division between analysis and prescription based on hardware and those based on software.

• Nuclear Engineering and Technology
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• 제44권1호
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• pp.43-52
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• 2012

To compute a permeability coefficient along a rough fracture that takes into account the fracture geometry, this study performed detailed measurements of fracture roughness using a confocal laser scanning microscope, a quantitative analysis of roughness using a spectral analysis, and a homogenization analysis to calculate the permeability coefficient on the microand macro-scale. The homogenization analysis is a type of perturbation theory that characterizes the behavior of microscopically inhomogeneous material with a periodic boundary condition in the microstructure. Therefore, it is possible to analyze accurate permeability characteristics that are represented by the local effect of the facture geometry. The Cpermeability coefficients that are calculated using the homogenization analysis for each rough fracture model exhibit an irregular distribution and do not follow the relationship of the cubic law. This distribution suggests that the permeability characteristics strongly depend on the geometric conditions of the fractures, such as the roughness and the aperture variation. The homogenization analysis may allow us to produce more accurate results than are possible with the preexisting equations for calculating permeability.

• Geomechanics and Engineering
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• 제30권1호
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• pp.67-73
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• 2022

In this study, the fiber orientation distribution (FOD) is investigated using both micro-CT (computerized tomography) and image analysis of physically cut specimens prepared from Polyvinyl Alcohol (PVA) fiber reinforced cemented Toyoura sand. The micro-CT images of the fiber reinforced cemented sand specimens were visualized in horizontal and vertical sections. Scans were obtained using a frame rate of two frames and an exposure time of 500 milliseconds. The number of images was set to optimize and typically resulted in approximately 3000 images. Then, the angles of the fibers for horizontal sections and in vertical section were calculated using the VGStudio MAX software. The number of fibers intersecting horizontal and vertical sections are counted using these images. A similar approach was used for physically cut specimens. The variation of results of fiber orientation between micro-CT scans and visual count were approximately 4-8%. The micro-CT scans were able to precisely investigate the fiber orientation distribution of fibers in these samples. The results show that 85-90% of the PVA fibers are oriented between ±30° of horizontal, and approximately 95% of fibers have an orientation that lies within ±45° of the horizontal plane. Finally, a comparison of experimental results with the generalized fiber orientation distribution function 𝜌(θ) is presented for isotropic and anisotropic distribution in fiber reinforced cemented Toyoura sand specimens. Experimentally, it can be seen that the average ratio of the number of fibers intersecting the finite area on a vertical plane to number of fibers intersecting the finite area on a horizontal plane (N^V_tot/N^H_tot) cut through a sample varies from 2.08 to 2.12 (an average ratio of 2.10 is obtained in this study). Based up on the analytical predictions, it can be seen that the average N^V_tot/N^H_tot ratio varies from 2.13 to 2.17 for varying n values (an average ratio of 2.15).