• 한국연소학회:학술대회논문집
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• 1998.10a
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• pp.1-8
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• 1998

Waste combustion above a grate is the core process of incineration systems, stability of which should be guaranteed for emission minimization. However, complicated reactions and heat and mass transfer phenomena make understanding the process difficult. One dimensional bed combustor with a numerical combustion model is utilized to investigate the combustion process of the bed, using cubic wood particles as a simulated fuel. Bed combustion behavior is characterized with apparent flame propagation speed, which has close relationship with air supply rate and chemical and physical characteristics of the fuel. Base on the availability of oxygen, two distinct reaction zone is identified; the oxygen-limited and the reaction-limited zone leading to the extinction by excessive convection cooling. The numerical modeling shows good agreement with the experimental results. The transient bed combustion behavior of local temperature and oxygen consumption rate is adequately reproduced. The numerical model is extended to model the waste bed combustion of a commercial incineration plant, which shows meaningful results as well.

• Structural Engineering and Mechanics
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• v.59 no.1
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• pp.123-132
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• 2016

Many military and commercial aging aircrafts flying beyond their design life may experience severe crack and corrosion damage, and thus lead to catastrophic failures. In this paper, were used in a finite element model to evaluate the effect of corrosion on the adhesive damage in bonded composite repair of aircraft structures. The damage zone theory was implemented in the finite element code in order to achieve this objective. In addition, the effect of the corrosion, on the repair efficiency. Four different patch shapes were chosen to analyze the adhesive damage: rectangular, trapezoidal, circular and elliptical. The modified damage zone theory was implemented in the FE code to evaluate the adhesive damage. The obtained results show that the adhesive damage localized on the level of corrosion and in the sides of patch, and the rectangular patch offers high safety it reduces considerably the risk of the adhesive failure.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2011.04a
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• pp.147-152
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• 2011

The purpose of this study is to find out the commercialization cause of 2nd class residential area in urban center as basic research to protect urban residential area against the pressure of commercialization. Through the research that are based on literature, field survey and urban planning map, it analysed the commercialization cause of selected two sites under similar urban condition ; to be a nearby subway station and to be a famous commercial street in site, etc. The consequences of this study are summarized as follows ; First the distance between subway station and residential block and residential commercialization are in inverse proportion each other. Second, the corner lot of a block and the access street directly connected collector street are very important factors to spread commercialization to residential area. Finally, nevertheless first and second results, there is square zone which is very high rate of commercialization within one regardless the distance between subway and residential block. the maximum range of square zone is assumed about 250 meter based on case study.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.497-504
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• 2002

The purpose of this study is to analyze thermal cycles and to investigate microstructures of heat affected zones for a low alloy carbon steel pipe under a multipass weld. The commercial finite element code SYSWELD is used to compute thermal cycles during multipass weld. The numerical results such as thermal cycles and size of heat affected zone are compared with those of the experiment and the two results show a good agreement. In addition, the microstructure and hardness are investigated from the weldment in detail. The weakest location is founded at intercritical region near the base metal.

• Journal of the Korea Furniture Society
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• v.20 no.4
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• pp.281-289
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• 2009

This research examined the technical feasibility of composite that had two layers of fiberglass reinforcement to enhance the load carrying capacity of lumber. Specimens were prepared from standard lumber made of thinning crop trees such as Larix kaempferi, Pinus koraiensis, and P. rigida. Results indicated that bending properties, hardness, and wood screw withdrawal load of low density lumber from the P. koraiensis increased as the number of layers of fiberglass reinforcement increased. Composite produced by VARTM method showed the MOE increased in all specimens, while the MOR differed on the location, whether the 2-layers of FRP is put on tensile zone or compressive zone. The MOR of high density lumber from Larix kaempferi and P. rigida decreased when they placed into tensile zone, but low density lumber from P. koraiensis increased in same location. The bending toughness only increased high density lumber of Larix kaempferi as the number of layers of fiberglass reinforcement increased. The technique developed by this study may increase an opportunity to use small diameter log with low density for commercial purposes.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.51-58
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• 2003

A cycle simulation method is developed by coupling a commercial code, Ricardo's WAVE, with the SENKIN code from CHEMKIN packages to predict combustion characteristics of an HCCI engine. By solving detailed chemical kinetics the SENKIN code calculates the combustion products in the combustion chamber during the valve closing period, i.e. from IVC to EVO. Except the combustion chamber during the valve closing period the WAVE code solves thermodynamic status in the whole engine system. The cycle simulation of the complete engine system is made possible by exchanging the numerical solutions between the codes on the coupling positions of the intake port at IVC and of the exhaust port at EVO. This method is validated against the available experimental data from recent literatures. Auto ignition timing and cylinder pressure are well predicted for various engine operating conditions including a very high ECR rate although it shows a trend of sharp increase in cylinder pressure immediate after auto ignition. This trend is overpredicted especially for EGR cases, which may be due to the assumption of single-zone combustion model and the limit of the chemical kinetic model for the prediction of turbulent air-fuel mixing phenomena. A further work would be needed for the implementation of a multi-zone combustion model and the effect of turbulent mixing into the method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.4
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• pp.351-357
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• 2022

In this study, a direction for deregulation that can increase the use of drones in the field of spatial information is presented. Regulations and administrative procedures for drone operation showed similar procedures in Japan, the United States, and Korea, such as reporting flight equipment, driver's license, and prohibition of flying within a specific flight zone. In the United States, policies to encourage the use of commercial drones have been implemented, and Japan has slightly tightened regulations on drone operation to protect the Olympics and important national facilities. As a result of the study, in the area where drone operation is restricted for geospatial data construction, Korea was setting the largest area, and GIS analysis showed that Korea's drone flight restricted area was more than 19.4% of the country's land area. In order to increase the utilization of drones in the construction and utilization of spatial information in the future, it is necessary to reset the drone flight restriction zone and reduce the area of the drone flight restriction zone. In addition, it was found that Korea is the only country that has formal and specific regulations on geospatial information security management. In order to increase the construction of geospatial information using drones, it is necessary to ease GSD (Ground Sample Distance)regulations.

• Korean Journal of Optics and Photonics
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• v.23 no.6
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• pp.255-263
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• 2012

In this paper, we designed a tabletop display which enables two viewers each to see a different image simultaneously within his/her defined viewing zone. In order to construct the designed viewing zones, we found the basic design conditions for a parallax barrier with a commercial LCD panel. As the viewing zones for two viewers are formed with only two view-point design, the interval between the center positions of each viewing zone and the width of each viewing zone are small compared to designed values. We analyzed the primary cases, introduced two modified design methods to enlarge the interval and the width of the viewing zones, and simulated their characteristics. As designed with six unit view-point and each viewing zone of each viewer is formed with a merged view-point, we found that adequate interval and width of viewing zones can be made, and we verified it in comparison with the tabletop display module that we fabricated.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.104-113
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• 2005

This landscape design proposal was presented for a competition for mixed-use development project by project financing in Asan Baebang which was held by the Korea National Housing Corporation in July of 2005. The site is a center of Asan Baebang New Town Development District and has a commercial area of $57,929m^{2}$. Design guidelines and judging criteria of this competition were to build a symbolic center and cultural core for district, to elevate positive image and identity of Asan New Town by attractive place making, to link with separated block in the site and regional context, and to make environmentally sustainable design by creating an attractive waterfront of Jang Jae stream passing through the site. This is the most important condition for the design. Therefore, the authors developed design concept and strategy within the guidelines and this conditions. The schema of the design was introduced by the water in the site. To evolve design concept, we reinterpreted water and context in the site combining with landscape design strategy. So the proposal set the main design concept as 'all that is solid melt into water' as if Marshall Berman said. By doing that, design concept of the proposal evolved as follows: 'extension' of water and greer, 'a joint' of space,'newness' of experience, 'breath' of consensus with each other. The spatial concept of this project was developed by expressing five theme spaces; eco zone, entertainment zone, art zone, culture zone, leisure zone. These theme spaces were consecutively placed along the pedestrian path and to consists of vertical layer in each level and diverse design technique and spatial effects are used.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.244-251
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• 2015

BACKGROUND: Recent studies have described the importance of bacteria that can degrade polycyclic aromatic hydrocarbons (PAHs). Here we screened bacterial isolates from commercial gasoline for PAH degraders and characterized their ability to degrade PAHs, lipids and proteins as well as their enantioselective epoxide hydrolase activity, salt tolerance, and seawater survival. METHODS AND RESULTS: One hundred two bacteria isolates from commercial gasoline were screened for PAH degraders by adding selected PAHs on to the surface of agar plates by the sublimation method. A clear zone was found only around the colonies of PAH degraders, which accounted for 13 isolates. These were identified as belonging to Bacillus sp., Brevibacterium sp., Micrococcus sp., Corynebacterium sp., Arthrobacter sp., and Gordonia sp. based on 16S rRNA sequences. Six isolates belonging to Corynebacterium sp., 3 of Micrococcus sp., Arthrobacter sp. S49, and Gordonia sp. H37 were lipid degraders. Arthrobacter sp. S49 was the only isolate showing high proteolytic activity. Among the PAH-degrading bacteria, Arthrobacter sp. S49, Brevibacterium sp. S47, Corynebacterium sp. SK20, and Gordonia sp. H37 showed enantioselective epoxide hydrolase activity with biocatalytic resolution of racemic styrene oxide. Among these, highest enantioselective hydrolysis activity was seen in Gordonia sp. H37. An intrinsic resistance to kanamycin was observed in most of the isolates and Corynebacterium sp. SK20 showed resistance to additional antibiotics such as tetracycline, ampicillin, and penicillin. CONCLUSION: Of the 13 PAH-degraders isolated from commercial gasoline, Arthrobacter sp. S49 showed the highest lipid and protein degrading activity along with high active epoxide hydrolase activity, which was the highest in Gordonia sp. H37. Our results suggest that bacteria from commercial gasoline may have the potential to degrade PAHs, lipids, and proteins, and may possess enantioselective epoxide hydrolase activity, high salt tolerance, and growth potential in seawater.