http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A Study on the Improvement of EXPLOSION TEST on Blast-Proof Door
Sangho Baek J-INSTITUTE 2021 International Journal of Military Affairs Vol.6 No.2
Purpose: In this paper, the development direction of the blast-proof door verification test was suggested through analysis of the blast-proof door verification test that has been conducted so far. Blast-proof doors are protective equipment that withstands storm pressure from enemy weapons at the outermost part of the build-ing in case of emergency, and must be verified before installation. To ensure the durability and stability of the blast-proof door, the explosion-proof test of the blast-proof door has been conducted four times since 2016. Method: In the meantime, as domestic blast-proof door certified products came out through explosion-proof tests of blast-proof doors, it has opened the way for domestic blast-proof doors to be used instead of expensive overseas products in domestic protection facilities and evacuation facilities. Based on the progress of the last four demonstration tests and certification results, the opinions of the Korea Gas Safety Corporation, the De-fense Installations Agency, and explosion-proof door manufacturers were synthesized to derive improvements. In addition, the explosion-proof door certification procedure and certification standards were reviewed, and the explosion-proof door manufacturing process and documents submitted by the companies that applied for the certification test were reviewed. Results: As a result of reviewing the requests of the host organization and explosion-proof door manufac-turers in the process of preparing the demonstration test such as purchasing TNT, preparing the test site, con-ducting an explosion test, and issuing a certificate, the need for improvement in the implementation of the demonstration test was identified. Improvement needs were identified in the agency in charge of the demon-stration test, the verification method, the method of measuring the displacement of the explosion-proof door after the explosion, and the alternative method of the demonstration test. Conclusion: I suggested that the explosion-proof test of the blast-proof door be supervised by the military institution. Through this, it is expected that the work related to the explosion-proof test will be more efficiently controlled. Also I concluded that it is necessary to supplement the method of measuring the displacement of the blast-proof door, and consider implementing a reduced-scale explosion test. In addition, it is proposed to supplement and develop the blast-proof door blasting demonstration test through computer simulation using the empirical test data accumulated in the future. Once the explosion-proof test of the blast door is improved as suggested in the conclusions, it is clear that the result will be of benefit to the military, companies, and ulti-mately the people who will be provided with certified high-quality blast-proof doors and installed in the protec-tion facilities.
A Study on the Economical Design of Protection Facilities through EXPLOSION TEST and Simulation
Sangho Baek,Sukbong Kim J-INSTITUTE 2021 International Journal of Military Affairs Vol.6 No.4
Purpose: In this study, the possibility of economical design of a protective structure was presented based on explosion test data and computer simulation results on the safety of both a building and human bodies for the combat training building. Method: A training facility was built for soldiers to experience the vibration, pressure, and noise generated inside the building due to the explosion of the TNT. In the explosion proof test, 9lb of TNT, equivalent to the weight of a 4.2-inch mortar shell, was detonated in four places around the building, including the roof of the training building, the door, and the outside of the wall to determine the damage. Vibration, pressure and noise transmitted into the building were measured. After the explosion test, the damage to the building was examined through a rebound hardness test and visual inspection, and the impact on the human body was estimated by measuring the pressure at three spots inside the building. Afterwards, computer modeling and simulation was performed using High Explosion Damage & Injury Assessment Model(HExDAM) and simulation results were com-pared with explosion test measurements. Results: As a result of inspecting the structural damage of the building, there was no significant displacement of the structure and it was determined that there was no problem in using the building. The compressive strength of concrete was observed through Schmidt hammer, it showed 96% of the strength compared to the design strength(30MPa). The pressure inside the building was measured in the range between 0.063 and 0.488 kPa, which is a very small value that is harmless to the human body. According to computer simulation, the internal pressure increased as the wall thickness decreased. However, even if the wall thickness was reduced, the pressure delivered to the inside did not increase significantly, and it was still found to be harmless to the human body. Conclusion: Through the explosion test, it was confirmed that the structure and personnel inside the training building for combat field experience were safe enough against the explosive power of a 4.2-inch mortar shell. Computer simulations showed that there is room for reducing the thickness of the wall of the building, and the necessity of economical design was suggested by using computer simulation for designing protection facilities and military facilities.
Baek, Youngbin,Seo, Dong Kyun,Choi, Jong Ho,Lee, Byeongho,Kim, Yong Hyup,Park, Seung Min,Jung, Jungwoo,Lee, Sangho,Yoon, Jeyong Taylor Francis 2016 Desalination and Water Treatment Vol.57 No.58
<P>Carbon nanotube (CNT) membranes are considered as next-generation membranes for desalination. Among the various types of CNT membranes, vertically aligned (VA) CNT membranes provide rapid water transport. However, when the water permeability of VA CNT membranes are compared with those of the commercial membrane, the VA CNT membranes only showed slightly higher water permeability due to their low pore densities. Additionally, the applicability of VA CNT membranes for desalination has been limited due to their larger pore sizes. Herein, we improved VA CNT membranes in terms of the desalination potential, flux enhancement, and scale-up. For the desalination potential, graphene oxide (GO) or polyamide (PA) were coated on a VA CNT membrane as a selective layer, which showed approximately 40-65% NaCl rejection, respectively. A pretreatment polyelectrolyte coating for a GO-coated VA CNT membrane increased the water permeability by approximately 50%. For the flux enhancement, the water permeability of a VA CNT membrane was nearly doubled when the VA CNT forest was mechanically densified by half. Finally, an enlarged VA CNT forest (2 x 2 cm(2)), sequential VA CNT forests (1 x 1 cm(2)) in a large cast, and an assembly of the VA CNT membrane were suggested as scale-up approaches.</P>
Recovery of Metal from ASR by the Corona Electrostatic Separation Method
( Insang Jung ),( Sangho Baek ),( Hoseok Jeon ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 3RINCs초록집 Vol.2015 No.-
This study was performed on the metal recovery from the ASR(Automobile Shredder Residues) using Corona Electrostatic Separator. The results of experiment are shown as the recovery and grade(metal content) of the metal obtained from ASR as a function of variations of size of fractures, electric voltage of electrode, rotor speed of separator and number of separation. As a result, it appears that the recovery and grade of metal are 80% and 46%, respectively at the optimum conditions of fracture size of minus 2mm, rotor speed of 60 rpm, electric voltage of 40 kV dc and one time separation. Finally, however, it results that the increase of number of separation attains the better recovery and grade of metal such as 90% and 50%, respectively at 4 time separations.
Kwoun Oh-Ig,Baek Sangho,Lee Hyongki,Sohn Hong-Gyoo,Han Uk,Shum C. K. The Korean Society of Remote Sensing 2005 大韓遠隔探査學會誌 Vol.21 No.1
We construct improved geocentric digital elevation model (DEM), estimate tidal dynamics and ice stream velocity over Sulzberger Ice Shelf, West Antarctica employing differential interferograms from 12 ERS tandem mission Synthetic Aperture Radar (SAR) images acquired in austral fall of 1996. Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry profiles acquired in the same season as the SAR scenes in 2004 are used as ground control points (GCPs) for Interferometric SAR (InSAR) DEM generation. 20 additional ICESat profiles acquired in 2003-2004 are then used to assess the accuracy of the DEM. The vertical accuracy of the OEM is estimated by comparing elevations with laser altimetry data from ICESat. The mean height difference between all ICESat data and DEM is -0.57m with a standard deviation of 5.88m. We demonstrate that ICESat elevations can be successfully used as GCPs to improve the accuracy of an InSAR derived DEM. In addition, the magnitude and the direction of tidal changes estimated from interferogram are compared with those predicted tidal differences from four ocean tide models. Tidal deformation measured in InSAR is -16.7cm and it agrees well within 3cm with predicted ones from tide models. Lastly, ice surface velocity is estimated by combining speckle matching technique and InSAR line-of-sight measurement. This study shows that the maximum speed and mean speed are 509 m/yr and 131 m/yr, respectively. Our results can be useful for the mass balance study in this area and sea level change.