• Korean Chemical Engineering Research
• /
• v.57 no.4
• /
• pp.475-483
• /
• 2019

Special chemical warfare agents are lethal gases that attack the human respiratory system. One of such gases are blood agents that react with the irons present in the electron transfer system of the human body. This reaction stops internal respiration and eventually causes death. The molecular sizes of these agents are smaller than the pores of an activated carbon, making chemical adsorption the only alternative method for removing them. In this study, we carried out a Computational Fluid Dynamics simulation by passing a blood agent: cyanogen chloride gas through an SG-1 gas mask canister developed by SG Safety Corporation. The adsorption bed consisted of a Silver-Zinc-Molybdenum-Triethylenediamine activated carbon impregnated with copper, silver, zinc and molybdenum ions. The kinetic analysis of the chemical adsorption was performed in accordance with the test procedure for the gas mask canister and was validated by the kinetic data obtained from experimental results. We predicted the dynamic behaviors of the main variables such as the pressure drop inside the canister and the amount of gas adsorbed by chemisorption. By using a granular packed bed instead of the Ergun equation that is used to model porous materials in Computational Fluid Dynamics, applicable results of the activated carbon were obtained. Dynamic simulations and flow analyses of the chemical adsorption with varying gas flow rates were also executed.

• Journal of Pharmacopuncture
• /
• v.4 no.1
• /
• pp.123-124
• /
• 2001

Purpose. Free radicals are implicated in the pathophysiology of aging, ischemic injury and neurodegenerative disorders. To deform]no whether Hominis Placenta extract prevents $H_2O_2$-induced apoptosis, we have performed morphological and biochemical analyses for the detection of apoptotic phenomena in the pineal tumor cell line $PGT-{\beta}$ We have also peformed cytochemical and immunocytochemical analyses for the detection of changes in nitric oxide synthase (NOS) activity and estimated the expression . of apoptotic genes using reverse transcription-polymerase chain reaction (RT-PCR) Methods. $PGT-{\beta}\;cells$ were pretreated with Hominis Placenta extracts $(0,\;10^{-2}\;{\mu}g/ml)$ for 2 hours and then exposed to $H_2O_2\;(0,\;50\;{\mu}M)$ for 3 hours. Appearance of apoptotic characteristics were monitored using 4, 6-diamidino-2-phenylindole dihydrochloride (DAPI) staining assay, terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay and flow cytometric analysis. NOS activity was measured by NADPH-diaphorase cytochemistry. Expression of inducible NOS (iNOS) and nuclear factor kappa B (NF k B) was assessed via immunocytochemistry. The expression of apoptotic genes was examined by RT-PCR. Results. After 3 flours of exposure to $H_2O_2$, it was shown that $PGT-{\beta}\;cells$ treated with $H_2O_2(50\;{\mu}M)$ exhibit classical apoptotic features and increases in NOS activity and caspase-3 expression. Treatment with Hominis Placenta extract resulted in a reduced occurrence of apoptotic features. DAPI staining, TUNEL and flow cytometric assays revealed decreases in the occurrence of nuclear fragmentation and in the sub-Gl fraction in the $PGT-{\beta}\;cells$ treated with Hominis Placenta extract. Cells treated with Hominis Placenta extract also showed lower activity of NADPH-diaphorase and immunoreactivities of both iNOS and NF k B than those of $H_2O_2$-treated cells which were not treated with Hominis Placenta extract. By RT-PCR, it was shown that the level of caspase-3 mRNA was derreased In the cells treated with Hominis Placenta . extract. Conclusions. This study shows that Hominis Placenta extract prevents $H_2O_2$-induced apoptosis in $PGT-{\beta}\;cells$; inhibitions of iNOS and caspnse-3 are possible mechanisms of the protection against apoptosis.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.28 no.3
• /
• pp.217-240
• /
• 2017

The purpose of this study was to investigate the semantic network analysis to understand image contents and to examine the degree to which words, word clusters contributed to the formation of semantic map within image contents. For this research, from 1993 until 2016 the field of the image contents were collected for a total of 2,624 cases papers. The word appeared in Title analyzed the social network by using the R program of Big Data. The results were as follows: First, The field of image contents is based on researches related to 'image', 'media' and 'contents'. Second, there is a three-step flow ('education' -> 'media' -> 'contents') of research in the field of image contents. Third, researches related to 'broadcasting', 'digital', 'technology', and 'production' were continuously carried out. Finally, There were new research subjects for each regime.

• The Journal of Engineering Geology
• /
• v.29 no.3
• /
• pp.237-249
• /
• 2019

The roughness changes on a fracture surface were analyzed via a multi-stage compression test under high temperatures to assess how the cracks in a rock mass affect groundwater movement. The analyzed samples consist of coarse granitic rocks from approximately 40 and 270 m depth, and fine granitic rocks from 500 m depth. The compression test was conducted on $20{\times}40{\times}5mm$ samples using a loading system where the pressure increases in 10 MPa increments to 120 MPa. A high-resolution 3D confocal laser scanning microscope (CLSM) was used to observe the surface changes, including the roughness changes, at each pressure step. The roughness change was calculated based on the roughness factor. The experimental results indicate that the roughness of the fracture surface varies with rock type under the stepwise pressure conditions. These data provide a basis for predicting groundwater flow along rock fractures.

• Journal of the Society of Naval Architects of Korea
• /
• v.31 no.4
• /
• pp.73-81
• /
• 1994

The source and source/dipole distribution methods using 3-dimensional panel method have been widely used for ship motion analysis. When these methods are used, large errors in the predicted hydrodynamic coefficients are introduced around the irregular frequencies caused by the resonance of imaginary internal flow. Therefore, the irregular frequencies need to be removed for an accurate prediction of ship motion. This paper adopts 3-dimensional translating and oscillating Green function derived by Wu. The adaptive integration method, stretching transform and stationary phase method are used for the calculation of the calculation of Green function and the integral equation is derived by distributing the Green function n ship surface and inner free-surface. The condition of zero normal velocity, that is, wall condition on inner free-surface has been successfully used for the removal of irregular frequencies in oscillating problems. The calculations are carried out for series 60($C_B=0.7$) vessel and the results are compared with those of other theoretical analyses and experiment.

• PNF and Movement
• /
• v.21 no.3
• /
• pp.345-356
• /
• 2023

Purpose: The aim of this study was to investigate the effects of physical therapy combined with a virtual reality (VR) game on pain, quality of life (QOL), engagement, and knee function in post-knee-surgery patients. Methods: Twenty-four patients who had undergone knee surgery four weeks or more before the study were recruited. Two withdrew from the study during the four-week experimental period, and a total of 22 patients were included in the final analysis. Routine physical therapy consisting of electrostimulation (10 min.) and therapeutic massage (10 min.) was the base intervention for all groups. The experimental group (n = 10) was additionally exposed to a VR game intervention, while the control group (n = 12) underwent an intervention involving similar motions as the experimental intervention but with no VR. The intervention for the experimental group used the game Rig Fit Adventure on Nintendo switch. Both groups underwent their respective interventions 3 times a week (35 min. per session) for 4 weeks. Pain was assessed using the numeric rating scale (NRS), and QOL was assessed using the EuroQol five-dimensional five-level questionnaire (EQ-5D-5L). Engagement was assessed using the Korea flow state scale (K-FSS). Finally, knee movement and function were assessed based on knee flexion and extension, range of motion (ROM), and Western Ontario and McMaster Universities Arthritis Index (WOMAC). Results: After the four-week physical therapy, both groups showed significant reductions in pain (on the NRS), increased knee ROM (flexion), better WOMAC scores, and increased EQ-5D-5L scores (p < 0.05), with the experimental group showing significantly better improvements in EQ-5D-5L and K-FSS scores (p < 0.05). Conclusion: The results of this study confirm that a VR-game-integrated intervention is effective for improving pain, QOL, engagement, and knee function in post-knee surgery patients and that VR-game-integrated interventions could be therapeutic alternatives for patients bedridden for prolonged periods with little motivation for rehabilitation.

• Journal of the Korean GEO-environmental Society
• /
• v.25 no.4
• /
• pp.21-28
• /
• 2024

In this study, a polyhedral domain decomposition method for Smoothed Particle Hydrodynamics (SPH) analysis is introduced. SPH which is one of meshless methods is a numerical analysis method for fluid flow simulation. It can be useful for analyzing fluidic soil or fluid-structure interaction problems. SPH is a particle-based method, where increased particle count generally improves accuracy but diminishes numerical efficiency. To enhance numerical efficiency, parallel processing algorithms are commonly employed with the Cartesian coordinate-based domain decomposition method. However, for parallel analysis of complex geometric shapes or fluidic problems under dynamic boundary conditions, the Cartesian coordinate-based domain decomposition method may not be suitable. The introduced polyhedral domain decomposition technique offers advantages in enhancing parallel efficiency in such problems. It allows partitioning into various forms of 3D polyhedral elements to better fit the problem. Physical properties of SPH particles are calculated using information from neighboring particles within the smoothing length. Methods for sharing particle information physically separable at partitioning and sharing information at cross-points where parallel efficiency might diminish are presented. Through numerical analysis examples, the proposed method's parallel efficiency approached 95% for up to 12 cores. However, as the number of cores is increased, parallel efficiency is decreased due to increased information sharing among cores.

• Journal of the Korean Institute of Gas
• /
• v.24 no.2
• /
• pp.1-8
• /
• 2020

Centrifugal pump is a facility that transfers energy to fluid through centrifugal force, which is usually generated by rotating the impeller at high speed, and is a major process facility used in many LNG production bases such as vaporization seawater pump, industrial water and fire extinguishing pump using seawater. to be. Currently, pumps in LNG plant sites are subject to operating conditions that vary depending on the amount of supply desired by the customer for a long period of time. Pumps in particular occupy a large part of the consumption strategy at the plant site, and if the optimum operation condition is not available, it can incur enormous energy loss in long term plant operation. In order to solve this problem, it is necessary to identify the performance deterioration factor through the flow analysis and the result analysis according to the fluctuations of the pump's operating conditions and to determine the optimal operation efficiency. In order to evaluate operation efficiency through experimental techniques, considerable time and cost are incurred, such as on-site operating conditions and manufacturing of experimental equipment. If the performance of the pump is not suitable for the site, and the performance of the pump needs to be reduced, a method of changing the rotation speed or using a special liquid containing high viscosity or solids is used. Especially, in order to prevent disruptions in the operation of LNG production bases, a technology is required to satisfy the required performance conditions by processing the existing impeller of the pump within a short time. Therefore, in this study, the rotation difference of the pump was applied to the ANSYS CFX program by applying the modified 3D modeling shape. In addition, the results obtained from the flow analysis and the curve fitting toolbox of the MATLAB program were analyzed numerically to verify the outer diameter correction theory.

• The KIPS Transactions:PartD
• /
• v.13D no.1 s.104
• /
• pp.67-74
• /
• 2006

The security requirements identification in the software development has received some attention recently. However, previous methods do not provide clear method and process of security requirements identification. We propose a process that software developers can build application specific security requirements from state transition diagrams at the security threat location. The proposed process consists of building model and identifying application specific security requirements. The state transition diagram is constructed through subprocesses i) the identification of security threat locations using security failure data based on the point that attackers exploit software vulnerabilities and attack system assets, ii) the construction of a state transition diagram which is usable to protect, mitigate, and remove vulnerabilities of security threat locations. The identification Process of application specific security requirements consist of i) the analysis of the functional requirements of the software, which are decomposed into a DFD(Data Flow Diagram; the identification of the security threat location; and the appliance of the corresponding state transition diagram into the security threat locations, ii) the construction of the application specific state transition diagram, iii) the construction of security requirements based on the rule of the identification of security requirements. The proposed method is helpful to identify the security requirements easily at an early phase of software development.

• Economic and Environmental Geology
• /
• v.53 no.1
• /
• pp.33-43
• /
• 2020

CO₂ geological storage is currently considered as the most stable and effective technology for greenhouse gas reduction. The saline formations for CO₂ geological storage are generally located at a depth of more than 800 m where CO₂ can be stored in a supercritical state, and an extensive impermeable cap rock that prevents CO₂ leakage to the surface should be distributed above the saline formations. Trough analysis of seismic and well data, we identified the basalt flow structure for potential CO₂ storage where saline formation is overlain by basalt cap rock around PZ-1 exploration well in the Southern Continental Shelf of Korea. To evaluate CO₂ storage capacity of the saline formation, total porosity and CO₂ density are calculated based on well logging data of PZ-1 well. We constructed a 3D geological grid model with a certain size in the x, y and z axis directions for volume estimates of the saline formation, and performed a property modeling to assign total porosity to the geological grid. The estimated average CO₂ geological storage capacity evaluated by the U.S. DOE method for the saline formation covered by the basalt cap rock is 84.17 Mt of CO₂(ranges from 42.07 to 143.79 Mt of CO₂).