• Journal of the Korean Society of Combustion
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• v.8 no.3
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• pp.24-30
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• 2003

A convolution algorithm combined with Fourier transformation has been applied to the tomographic reconstruction of asymmetric soot structure to identify the local soot volume fraction distribution. Line-of-sight integrated data from light extinction measurement with multi-angular scanning formed basic information for the deconvolution. Multi-peak following interpolation technique was applied to obtain the effect of increasing number of scanning angles. Height-by-height reconstructed soot volume fraction distribution was compared with laser-induced incandescence signals.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.1
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• pp.144-158
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• 2012

A higher spatial resolution is preferable to support the accuracy of detailed climate analysis in urban areas. Airborne LiDAR (Light Detection And Ranging) and satellite (KOMPSAT-2, Korea Multi-Purpose Satellite-2) images at 1 to 4 m resolution were utilized to produce digital elevation and building surface models as well as land cover maps at very high(5m) resolution. The Climate Analysis Seoul(CAS) was used to calculate the fractional coverage of land cover classes in built-up areas and thermal capacity of the buildings from their areal volumes. It then produced analyzed maps of local-scale temperature based on the old and new input data. For the verification of the accuracy improvement by the precise input data, the analyzed maps were compared to the surface temperature derived from the ASTER satellite image and to the ground observation at our detailed study region. After the enhancement, the ASTER temperature was highly correlated with the analyzed temperature at building (BS) areas (R=0.76) whereas there observed no correlation with the old input data. The difference of the air temperature deviation was reduced from 1.27 to 0.70K by the enhancement. The enhanced precision of the input data yielded reasonable and more accurate local-scale temperature analysis based on realistic surface models in built-up areas. The improved analysis tools can help urban planners evaluating their design scenarios to be prepared for the urban climate.

• Korean Journal of Remote Sensing
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• v.39 no.5_4
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• pp.1155-1164
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• 2023

Currently, the National Forest Inventory (NFI) collects tree information by human, so the range and time of the survey are limited. Research is actively being conducted to extract tree information from a large area using aerial Light Detection And Ranging (LiDAR) and aerial photographs, but it does not reflect the characteristics of forest areas in Korea because it is conducted in areas with wide tree spacing or evenly spaced trees. Therefore, this study proposed a methodology for generating Digital Surface Model (DSM), Digital Elevation Model (DEM), and Canopy Height Model (CHM) images using aerial LiDAR, extracting the tree height through the local Maxima, and calculating the Diameter at Breath Height (DBH) through the DBH-tree height formula. The detection accuracy of trees extracted through the proposed methodology was 88.46%, 86.14%, and 84.31%, respectively, and the Root Mean Squared Error (RMSE) of DBH calculated based on the tree height formula was around 5cm, confirming the possibility of using the proposed methodology. It is believed that if standardized research on various types of forests is conducted in the future, the scope of automation application of the manual national forest resource survey can be expanded.

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.21-33
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• 2020

Purpose: The objective of this research is to classify snowfall area types with consideration of past regional snowfall characteristics and times for the effective local snow removal response systems of 229 local government districts. Method: This research first collected snowfall data of South Korea meteorological stations, and classified regional types using successive snowfall time. This research finally produced GIS maps using regional type information of snowfalls by applying GIS analysis methods. Result: This research provides five types of snowfall regions including 'frequent heavy snowfall regions', 'frequent light snowfall regions', 'rare heavy snowfall regions', 'average snowfall regions', and 'rare light snowfall regions' based on analysis results. Conclusion: Results of this research can be used as basic information for regional demand estimations of snow removal equipments, materials, vehicles, and personnel for the efficient snow removal response systems.

• Korean Institute of Interior Design Journal
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• v.16 no.4
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• pp.81-88
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• 2007

The research made a study of the spatial characteristics of $m\'{e}diath\'{e}ques$ based on the twelve case studies of the BMVRs constructed with the financial support of the government since 1992 in France. The $m\'{e}diath\'{e}que$ is the community center for local residents to collect information, to have relationship with others and to shape public opinions. Thus it should have easy accessibility, liberal flow plan and the diversity of the newest information. The architectural elements to offer these faculties are summarized as follows. Firstly, the $m\'{e}diath\'{e}que$ as the public facility should have the easy flow plan and the high recognition for visitors. Second, it should be the efficient space for both managers and visitors. thus, it should not need more managers or have the difficulty to move. Third, it should be planed to support the change of the form of information and the needs of the visitors. It, therefore, should have the wide space with no wall and divide the space by movable furnitures. Lastly, it should be the space with the natural light, and it does not need the special artificial lights like museums. It is considered that the planning of the $m\'{e}diath\'{e}que$ should be from the four principles. Additionally, the program of the $M\'{e}diath\'{e}que$ should reflect the each local traits.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.4
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• pp.392-397
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• 2022

We present the structural and optical properties of Au@TiO₂ core-shell microsphere structure prepared by a hydrothermal synthesis method. As a way to improve the efficiency of organic solar cells, the Au@TiO₂ core-shell microsphere was synthesized to use the local surface plasmon resonance (LSPR) phenomenon. The synthesized results were confirmed to have the Au@TiO₂ core-shell structure using a high-resolution transmission electron microscopy. An absorption was observed to occur at 527 nm belonging to the visible light region using a visible light spectroscopy, which supports the LSPR phenomenon. We suggest that the Au@TiO₂ core-shell microsphere is highly likely to be applied to organic solar cells including dye-sensitized solar cells. In addition, we expect it to be widely used not only in the energy but also in the bio as well as in the environmental fields.

• Journal of Korea Game Society
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• v.6 no.2
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• pp.45-50
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• 2006

In order to generate a photo-realistic synthesized image, we should reconstruct light environment by 3D analysis of scene. This paper presents a novel method for identifying the positions and characteristics of the lights-the global and local lights-in the real image, which are used to illuminate the synthetic objects. First, we generate High Dynamic Range(HDR) radiance map from omni-directional images taken by a digital camera with a fisheye lens. Then, the positions of the camera and light sources in the scene are identified automatically from the correspondences between images without a priori camera calibration. Types of the light sources are classified according to whether they illuminate the whole scene, and then we reconstruct 3D illumination environment. Experimental results showed that the proposed method with distributed ray tracing makes it possible to achieve photo-realistic image synthesis. It is expected that animators and lighting experts for the film and animation industry would benefit highly from it.

• Transactions on Electrical and Electronic Materials
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• v.14 no.3
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• pp.160-163
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• 2013

We investigated the effect of light intensity and wavelength of a solar cell device by using photoconductive atomic force microscopy (PC-AFM). The $POCl_3$ diffusion doping process was used to produce a p-n junction solar cell device based on a Poly-Si wafer and the electrical properties of prepared solar cells were measured using a solar cell simulator system. The measured open circuit voltage ($V_{oc}$) is 0.59 V and the short circuit current ($I_{sc}$) is 48.5 mA. Also, the values of the fill factors and efficiencies of the devices are 0.7% and approximately 13.6%, respectively. In addition, PC-AFM, a recent notable method for nano-scale characterization of photovoltaic elements, was used for direct measurements of photoelectric characteristics in local instead of large areas. The effects of changes in the intensity and wavelength of light shining on the element on the photoelectric characteristics were observed. Results obtained through PC-AFM were compared with the electric/optical characteristics data obtained through a solar simulator. The voltage ($V_{PC-AFM}$) at which the current was 0 A in the I-V characteristic curves increased sharply up to 1.8 $mW/cm^2$, peaking and slowly falling as light intensity increased. Here, $V_{PC-AFM}$ at 1.8 $mW/cm^2$ was 0.29 V, which corresponds to 59% of the average $V_{oc}$ value, as measured with the solar simulator. Also, while light wavelength was increased from 300 nm to 1,100 nm, the external quantum efficiency (EQE) and results from PC-AFM showed similar trends at the macro scale, but returned different results in several sections, indicating the need for detailed analysis and improvement in the future.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.9
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• pp.1151-1162
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• 1999

The effects of radial heat and $H_2O$ diffusion on the evolution of silica particles in coflow diffusion flames have been studied experimentally. The evolution of silica aggregate particles in coflow diffusion flames has been measured experimentally using light scattering and thermophoretic sampling techniques. The measurements of scattering cross section from $90^{\circ}$ light scattering have been utilized to calculate the aggregate number density and volume fraction using with combination of measuring the particle size and morphology through the localized sampling and a TEM image analysis. Aggregate or particle number densities and volume fractions were calculated using Rayleigh-Debye-Gans and Mie theory for fractal aggregates and spherical particles, respectively. Flame temperatures and volumetric differential scattering cross sections have been measured for different flame conditions such as inert gas species, $H_2$ flow rates, and burner injection configurations to examine the relation between the formation of particles and radial $H_2O$ diffusion. The comparisons of oxidation and flame hydrolysis have also been made for various $H_2$ flow rates using $N_2$ or $O_2$ as a carrier gas. Results indicate that the role of oxidation becomes dominant as both carrier gas($O_2$) and $H_2$ flow rates increases since the radial heat diffusion precedes $H_2O$ diffusion in coflow flames used in this study. The effect of carrier gas flow rates on the evolution of silica particles have also been studied. When using $N_2$ as a carrier gas, the particle volume fraction has a maximum at a certain carrier gas flow rate and as the flow rate is further increased, the hydrolysis reaction Is delayed and the spherical particles finally evolves into fractal aggregates due to decreased flame temperature and residence time.

• Korean Journal of Human Ecology
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• v.15 no.4
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• pp.659-667
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• 2006

The purpose of this study is to identify the combinated factors of leaf mustard kimchi which confer the highest utility on tourists, and to establish the relative factors of importance in terms of tourists' contribution to total utility to their tour purpose. Conjoint model, $X^2$ analysis, Max. Utility model, BTL model, Logit model, K-means cluster analysis, and one-way ANOVA analysis are used for this study. The findings from this study are as follows: First, the Pearson's R and Kendall's tau($\tau$) statistics shows that the model fits the data well to the tourists' visit purpose. Second, when they choose a sightseeing place, tourists' taste for food renowned in the local area is a very important factor. Third, the leaf mustard kimchi some tourists most prefer has light red color and mild taste, and they buy it in a shaped packing, at a cheap price and directly at the kimchi factory. The leaf mustard kimchi the other tourists most prefer has light red color and highly pungent taste, and they buy it in a shaped packing, at a cheap price and directly at the kimchi factory. Fourth, by the results of BTL model and Logit Model analysis, some tourists most prefer an experimental model of leaf mustard kimchi which has light red color and mild taste. They want to buy it in a shaped packing, at a cheap price and directly at the kimchi factory. The other tourists most prefer an experimental model of leaf mustard kimchi which has light red color and highly pungent taste. They want to buy it in a shaped packing, at a cheap price and directly in the kimchi factory. Finally, the writer hopes this study will provide the kimchi marketers with some insights into the types of popular leaf mustard kimchi designs that could be successfully developed.