• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.5
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• pp.952-964
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• 1992

The interaction of natural convection and radiation heat transfer in a two dimensional square enclosure containing absorbing, emitting and linear anisotropically scattering gray medium is numerically analyzed. P-1 and P-3 approximation is introduced to calculate radiation heat transfer. The effects of scattering albedo, wall emissivity, scattering anisotropy, and optical thickness on the characteristics of the flow and temperature field and heat transfer are investigated. Temperature and velocity profiles depend a great deal on the scattering albedo, and the importance of this effect increases with decrease in albelo. Planck number is another important parameter in radiation heat transfer. The increase in scattering albedo increases convection heat transfer and decreases radiation heat transfer at hot wall. However, the increase in scattering albedo decreases both convection and radiation heat transfer at cold wall. The increase in optical thickness decreases radiation heat transfer. The scattering anisotropy has important effects on the radiation heat transfer only. The highly forward scattering leads to an increase of radiation heat transfer whereas the highly backward scattering leads to an decrease of radiation heat transfer. The effect of scattering anisotropy decreases when reducing the wall emissivity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3014-3021
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• 2015

Shell-tube heat exchanger is widely applied in industrial field by easily manufacturing as to various size and flow patterns. In this study, by changing baffle's cut direction, tilt angle and rotational angle as well as by using SST (Shear Stress Transport) $k-{\omega}$ turbulence model in ANSYS FLUENT v.14, the heat transfer rate and pressure drop characteristics of inner shell will be analyzed to improve heat transfer ability. As a result of analysis, heat transfer performance according to cut direction of baffle has been improved with vertical model B and angle $45^{\circ}$ model C than horizontal model A. In addition, the tilt $10^{\circ}$ of the baffle and rotational angle $0^{\circ}-90^{\circ}-180^{\circ}-270^{\circ}$ of model D showed better result in heat transfer rate and pressure drop.

• Tribology and Lubricants
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• v.32 no.3
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• pp.101-105
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• 2016

Trap effect of groove is evaluated in a lubricating system using computational fluid dynamics (CFD) analysis. The simulation is based on the standard k-ε turbulence model and the discrete phase model (DPM) using a commercial CFD code FLUENT. The simulation results are also capable of showing the particle trajectories in flow field. Computational domain is meshed using the GAMBIT pre-processor. The various grooves are applied in order to improve lubrication characteristics such as reduction of friction loss, increase in load carrying capacity, and trapping of the wear particles. Trap effect of groove is investigated with variations in cross-sectional shape and Reynolds number in this research. Various cross-sectional shapes of groove (rectangular, triangle, U shaped, trapezoid, elliptical shapes) are considered to evaluate the trap effect in simplified two-dimensional sliding bearing. The particles are assumed to steel, and defined a single particle injection condition in various positions. The “reflect” boundary condition for discrete phase is applied to the wall boundary, and the “escape” boundary condition to “pressure inlet” and “pressure outlet” conditions. The streamlines are compared with particles trajectories in the groove. From the results of numerical analysis in the study, it is found that the cross-sectional shapes favorable to the creation of vortex and small eddy current are effective in terms of particle trapping effect. Moreover, it is found that the Reynolds number has a strong influence on the pattern of vortex or small eddy current in the groove, and that the pattern of the vortex or small eddy current affects the trap effect of the groove.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.5
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• pp.1150-1157
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• 1988

Two-dimensional turbulent plane jet which is under the pressure gradient in the transverse direction is studied numerically. Full Navier-Stokes equations are used to correctly account for the pressure variation in the transverse direction. Using the standard k-.epsilon. turbulence model as a closure relationship, a time marching procedure gives the velocity field. The temperature fields are obtained for two different cases : (1) Hot jet is issued into the cold still air, and (2) Hot jet is issued into the surrounding across which exists a temperature difference. The velocity and temperature fields along with other flow and heat-transfer characteristics for two different pressure gradients are presented. A simple formula that relates the jet trajectory to the pressure gradient is also proposed. The mass flux in the longitudinal direction and the jet halfwidth seem insensitive to the pressure gradient. However, the pressure gradient increases the heat flux in the longitudinal direction as well as in the transverse direction.

• Journal of The Korea Institute of Healthcare Architecture
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• v.25 no.1
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• pp.17-27
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• 2019

Purpose: Clinical laboratory in hospital has taken a great role in protection of chronic disease. as well as diagnosis and treatment, And laboratory layout has been considered by the management and laboratory section more than the function and workflow. Methods: So this study figures out the workflows of laboratory sections in the recently upgraded Laboratory Medicine, and searches the functional relationships and spatial block diagram between each disciplines as follows. Literature review and expert adviser has been conducted. Results: 1) Laboratory type of Laboratory Medicine is divided into routine and specialized laboratory according to the workflow by automated or specialized test. 2) The general workflow consists of specimen collection, specimen classification, test by discipline, test report, and specimen disposal. 3) Though the function of each laboratory section is very complicated and specific, the characteristics and the workflow can be shown in detail by each lab through [Figure 4], [Figure 5], [Figure 6], [Figure 7], and [Figure 8]. 4) Functional relationship diagram can be displayed to the adjacency and relation between each laboratory and support spaces. 5) The spatial block diagram could be presented as shown in [Figure 10], in which the emergency lab lay in front side, routine lab in the central open area, and specialized lab in the behind side. Implications: This study can be used as a useful data in planning and designing a Laboratory Medicine Department.

• The Korean Fashion and Textile Research Journal
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• v.21 no.4
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• pp.432-451
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• 2019

Companies and brands that practice sustainability pay attention to New Media due to its ability to build a sustainable relationship between companies and consumers. The need for research on specific roles, characteristics, and social media effects on eco-friendly advertising has had rapid growth in marketing programs for sustainable activities especially shown through social media. Information about sustainable fashion has spread to consumers through social media, and multifarious efforts have been made to attract the attention of youth. Despite the dramatic increase in eco-friendly marketing through social media as a part of sustainability, there is a lack of research on the major influences of emotional factors such as ad color and expression in social media. In this context, it is meaningful to identify relationships between emotional responses, advertising value and consumer behavior of sustainable fashion brands in Instagram and implement a suitable advertising type (color vs expression) for consumers. We used 366 responses for the final analysis. Data were analyzed by factor analysis, structural equation modeling using SPSS 18.0 and AMOS 18.0. The results of this study suggest that emotional responses, advertising value have a significant effect on the flow. This study expands on a previously limited research field by verifying consumer responses to image advertising on Instagram, rather than general sustainable fashion marketing. The study results also provide meaningful implications for a relation formation between customers and fashion brands vis-${\grave{a}}$-vis sustainable social media marketing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.8
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• pp.599-606
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• 2019

The pulse gun device is designed to identify the transverse pressure wave propagation/damping mechanism into the combustion flow field and in the combustion chamber according to the arrangement of multiple injectors. The manufactured pulse gun was tested to verify operability at the target combustion pressure and control of the pressure wave intensity. Gas nitrogen was used to pressurize the high-pressure tube and an OHP film of $100{\mu}m$ thickness was used for the diaphragm. To check the speed and intensity of the pressure waves, the dynamic and static pressure were measured using the pressure transducer. The performance test confirmed that the manufactured pulse gun can generate pressure waves with transverse characteristics that can be controled for strength depending on the supply pressure.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.2
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• pp.217-225
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• 2019

Objectives: The aim of this study is to evaluate the quality management systems of domestic asbestos survey and monitoring service providers and the relationships with the number of licenses or designations and sales performances. Methods: Data on quality management systems were collected by assessors who were assigned by the Korea Occupational Safety and Health Agency(KOSHA) during a pilot evaluation program for designated asbestos survey and monitoring service providers in 2016 using evaluation criteria developed by KOSHA. Basic characteristics, evaluated scores, and sales performance were gathered and statistically analyzed. Results: The median and arithmetic mean of the total scores were 0.64 and 0.66. Evaluation fields that scored highly with the highest percentages were sales performance, installation and availability of equipment, compliance with the mandatory minimum number of airborne samples, laboratory independence, and results of proficiency analytical testing, in that order. Evaluation fields that received low marks with the highest percentages were the training of personnel, blank field samples, calibration of flow rates, preliminary check and visual inspection of the work area prior to the clearance test, and review and approval of final reports, in that order. Comparison of normalized scores between service providers registered for asbestos and other tasks and those designated for only asbestos showed significant differences in their evaluated scores. Sales performance did not show a positive correlation with evaluated scores. Conclusions: The quality management systems of domestic asbestos survey and monitoring service providers were poor. High scores were recorded mostly in evaluation fields related to regulatory requirements. Low scores were recorded mostly in evaluation fields related to documentation and recordkeeping. Considering the low influence of quality on sales performance, the government needs to evaluate the quality management of asbestos survey and monitoring service providers and provide the results to public in order to address their low levels of quality management.

• Animal Bioscience
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• v.34 no.8
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• pp.1253-1270
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• 2021

Assessment of male fertility is based on the evaluation of sperm. Semen evaluation measures various sperm quality parameters as fertility indicators. However, semen evaluation has limitations, and it requires the advancement and application of strict quality control methods to interpret the results. This article reviews the recent advances in evaluating various sperm-specific quality characteristics and methodologies, with the help of different assays to assess sperm-fertility status. Sperm evaluation methods that include conventional microscopic methods, computer-assisted sperm analyzers (CASA), and flow cytometric analysis, provide precise information related to sperm morphology and function. Moreover, profiling fertility-related biomarkers in sperm or seminal plasma can be helpful in predicting fertility. Identification of different sperm proteins and diagnosis of DNA damage has positively contributed to the existing pool of knowledge about sperm physiology and molecular anomalies associated with different infertility issues in males. Advances in methods and sperm-specific evaluation has subsequently resulted in a better understanding of sperm biology that has improved the diagnosis and clinical management of male factor infertility. Accurate sperm evaluation is of paramount importance in the application of artificial insemination and assisted reproductive technology. However, no single test can precisely determine fertility; the selection of an appropriate test or a set of tests and parameters is required to accurately determine the fertility of specific animal species. Therefore, a need to further calibrate the CASA and advance the gene expression tests is recommended for faster and field-level applications.

• Journal of Naturopathy
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• v.10 no.1
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• pp.56-65
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• 2021

Purposes: This study is to examine the causes of limitations of modern western science and philosophy through Ayurvedic thought, and to seek the path of holism for the development of national healing projects. Methods: Therefore, it was inferred that the background of modern Western civilization and the reality of the national healing project would share the flow. In order to examine this, the difference between the East and West's 'recognition of the body and the mind' and the 'perspective on the origin of existence' was examined, and the characteristics of the Ayurvedic five-element novel were examined. Results: Through that process, the "mind and body dualism" in the West and the absence of the "empty element( 空 Śunya)" in Western four-element novels were pointed out as the cause of the limitations. In the sense that the 'empty element' is an invisible world and an immaterial world, it was concluded that the absence of justice was a limitation of Western civilization and a problem of the reality of the national healing project. Conclusions: I hope that this study will lead to continuous research on Ayurvedic ideology and research in the field of natural healing, thus contributing to the development of national healing projects and leading to health, well-being, and self-healing of the people.