• Economic and Environmental Geology
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• v.38 no.4 s.173
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• pp.369-380
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• 2005

This study describes image-based approach for efficient and objective evaluation method of the rock slope stability. Three-dimensional rock slope model was reconstructed by processing stereo digital images. The model provided fundamental information for geospatial analysis of the rock slope. Methods to extract three-dimensional information about discontinuity on the rock slope and to estimate roughness of the rock surfaces were suggested. The results show that stereo digital images have potential to provide information for both quantitative and qualitative analysis of rock slope. In addition, visualization of the results increases efficiency and benefit in evaluating rock slope stability.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.2
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• pp.137-150
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• 2010

A meso-urban meteorological model (Urbanized MM5; uMM5) with urban canopy parameterization (UCP) was applied to the high-resolution simulation of meteorological fields in a complex coastal urban area and the assessment of urban impacts. Multi-scale simulations with the uMM5 in the innermost domain (1-km resolution) covering the Busan metropolitan region were performed during a typical sea breeze episode (4~8 August 2006) with detailed fine-resolution inputs (urban morphology, land-use/land-cover sub-grid distribution, and high-quality digital elevation model data sets). An additional simulation using the standard MM5 was also conducted to identify the effects of urban surface properties under urban meteorological conditions. Results showed that the uMM5 reproduced well the urban thermal and dynamic environment and captured well the observed feature of sea breeze. When comparison with simulations of the standard MM5, it was found that the uMM5 better reproduced urban impacts on temperature (especially at nighttime) and urban wind flows: roughness-induced deceleration and UHI (Urban Heat Island)-induced convergence.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2011.04a
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• pp.251-263
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• 2011

This study was carried out in order to investigate the effect of pre-coating layer on top-coating layer. The coated paper with five different formulations were prepared. The properties of coated paper were measured and correlation between pre and top-coated layer was evaluated. Paper gloss was increased with addition of clay and GCC that has smaller particle size. Roughness was decreased with using smaller particle GCC, clay and talc. The highest thickness was obtained with talc. Brightness and whiteness of pre-coated layer were affected to top-coated layer. GCC 60 shows the highest and ununiform water adsorption during 1sec. The adsorption was higher with increasing coated weight. Talc shows the excellent water adsorption properties due to its wettability. These results indicate that final printability and properties of top coating layer can be controlled with adjusting pre-coating layer.

• Journal of the Korean institute of surface engineering
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• v.52 no.6
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• pp.310-315
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• 2019

The use of a silicon carbide (SiC)-based composite ceramic layer for the mold of a curved cover glass was demonstrated. The stress of SiC/VDR/graphite-based mold structure was evaluated via finite element analysis. The results revealed that the maximum tensile stress primarly occured at the edge region. Moreover, the stress can be reduced by employing a relatively thick SiC coating layer and, therefore, layers of various thicknesses were deposited by means of chemical vapor deposition. During growth of the layer, the orientation of the facets comprising the SiC grain became dominant with additional intense SiC(220) and SiC(004). However, the roughness of the SiC layer increased with increasing thickness of the layer and. Hence, the thickness of the SiC layer needs to be adjusted by values lower than the tolerance band of the curved cover glass mold.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.287-295
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• 2017

This paper provides a mathematical approach for estimating flood risks due to the effects of climate change by developing a one dimensional (1D) hydraulic model for the mountainous river reaches located close to the Yeongwol thermal power plant. Input data for the model, including topographical data and river discharges measured every 10 minutes from July $1^{st}$ to September $30^{th}$, 2013, were imported to a 1D hydraulic model. Climate change scenarios were estimated by referencing the climate change adaptation strategies of the government and historical information about the extreme flood event in 2006. The down stream boundary was determined as the friction slope, which is 0.001. The roughness coefficient of the main channels was determined to be 0.036. The results show the effectiveness of the riverbed widening strategy through the six flooding scenarios to reduce flood depth and flow velocity that impact on the power plant. In addition, the impact of upper Namhan River flow is more significant than Dong River.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.1
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• pp.32-39
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• 2013

Although space-borne satellites are useful in obtaining information all around the world, they cannot observe at a suitable time and place. In order to overcome these limitations, an airborne remote sensing system was developed in this study. It is composed of a SAR sensor and a thermal infrared sensor. Additionally GPS, IMU, and thermometer/hygrometer were attached to the plane for radiometric and geometric calibration. The brightness of SAR image varies depending on surface roughness, and capillary waves on the sea surface, which are easily generated by sea winds, induce the surface roughness. Thus, sea surface wind can be estimated using the relationship between quantified SAR backscattering coefficient and the sea surface wind. On the other hand, thermal infrared sensor is sensitive to measure object's temperature. Sea surface temperature is obtained from the thermal infrared sensor after correcting the atmospheric effects which are located between sea surface and the sensor. Using these two remote sensing sensors mounted on airplane, four test flights were carried out along the west coast of Korea. The obtained SAR and thermal infrared images have shown that these images were useful enough to monitor coastal environment and estimate marine meteorology data.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.9
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• pp.572-576
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• 2017

A hybrid transparent electrode was fabricated with graphene and silver nanowires (Ag NWs). Three different processes were used to fabricate the hybrid electrode. Measurements of the sheet resistances, transmittances, and surface roughnesses of the hybrid electrodes were used to identify the optimal fabrication process. The surface roughness of the hybrid electrodes with Ag NWs embedded in a transparent polymer matrix was significantly lower than that of the other hybrid electrodes. A hybrid electrode fabricated by transferring graphene onto Ag NWs after spin-coating the Ag NWs onto the substrate showed the lowest sheet resistance. The transmittance of the hybrid electrodes was comparable to that of Ag NW electrodes.

• International Journal of Ocean System Engineering
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• v.2 no.4
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• pp.200-208
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• 2012

Surge overflow may cause damage on earthen levees. Levee strengthened on the levee crest and landward-side slope can provide protection against the erosion damage induced by surge overflow. In this paper, surge overflow of a roller compacted concrete RCC strengthened levee was studied in a purely Lagrangian and meshless approach, the smoothed particle hydrodynamics (SPH) method. After verifying the developed model with analytical solution and comparing the results with full-scale experimental data, the roughness and erosion parameters were calibrated. The water thickness, flow velocity, and erosion depth at crest, landward-side slope and toe were calculated. The characteristics of flow hydraulics and erosion on the RCC strengthened levee are given. The results indicate that the RCC strengthened levee can resist erosion damage for a long period.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.223-238
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• 2002

This paper presented on an environment estimation of cutting fluid which is a mouse model of acute bacterial rhinosinusitis using cutting fluid in grinding and cutting. Above results will be remarked the necessity of friendly environmental cutting skill when it had used in workshop. The results of a mouse experimental using cutting fluid showed that it are occurred to the respiratory organs sickness. Also cutting fluid are occurred to hurtfulness a person when it used to grinding and cutting in workshop. Also, the results of grinding experiments in avitation materials showed that surface roughness are superior to more emulsion type oil than vegetable type oil according to increase of the depth of cut. Grinding force are similar to both emulsion type oil and vegetable type oil.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.1051-1054
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• 2002

Environmentally conscious machining and technology have been taking more and more important position in machining process. Since cutting fluid has some impact on environment, many researches are being carried out to minimize the use of cutting fluid. It can be Increased the environmental pollution through not using coolant any more or minimizing it. In this study, the cooling effects of cutting methods using the compressed cold air, dry cutting and cutting fluid will investigate in the blade machining. In order to examine the characteristics of cutting and tool in the environmentally conscious machining, this work investigates experimentally the degree of tool wear, cutting force and characteristics of surface roughness in relation to machining conditions and cooling methods.