• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.366-374
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• 2009

To determine the optimum operating conditions of the indented cylinder length grader based on varietal characteristics, broken rice removal capabilities were measured on the milled rice of 41 varieties at different conditions consisted of 3 types of indented cylinders with different indent-opening diameters and 3 different collecting-angles of broken rice. The broken rice removal capabilities were swayed by the indent's opening diameter and depth as well as the angle of the collecting trough of broken rice on the point of instrument, and by the kernel length and width as well as 1000 grain weight of milled rice on the point of rice variety. When the angle of broken rice collecting-trough reached to near the horizontal center line of the indented cylinder on the direction of upward turning side, which was referred $0^{\circ}$ in this paper, the amount of rice collected in trough increased, whereas the loss of head rice also increased. Considering the removal rate of broken rice as well as loss of head rice, it was thought that the suitable angle of trough for broken rice collecting was located $5^{\circ}$ to $15^{\circ}$ depending on varietal characteristic and indent opening diameter. It was thought that 4.2 mm or more of indent opening diameter was recommendable for the rice varieties having heavier 1000 grain weight than 22.3g, as well as larger sizes than 2.9 and 5.2 mm in width and length of rice kernel, respectively; 3.8 mm for the small-sized thin kernels, and a proper diameter between 3.8 and 4.2 mm for short to middle kernels. The varieties with relatively shorter length compared to width of kernel were more difficult to separate the broken rice than the opposite ones. For effective separation of that, it seems that some specific indent shapes such as wider opening and shallow depth etc. are required. When the broken rice content were excessively high, wider diameters of indent openings than specified sizes were thought to be the better.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.619-628
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• 2009

LiDAR has capability of rapid data acquisition and provides useful information for reconstructing surface of the Earth. However, Extracting information from LiDAR data is not easy task because LiDAR data consist of irregularly distributed point clouds of 3D coordinates and lack of semantic and visual information. This thesis proposed methods for automatic extraction of buildings and 3D detail modeling using airborne LiDAR data. As for preprocessing, noise and unnecessary data were removed by iterative surface fitting and then classification of ground and non-ground data was performed by analyzing histogram. Footprints of the buildings were extracted by tracing points on the building boundaries. The refined footprints were obtained by regularization based on the building hypothesis. The accuracy of building footprints were evaluated by comparing with 1:1,000 digital vector maps. The horizontal RMSE was 0.56m for test areas. Finally, a method of 3D modeling of roof superstructure was developed. Statistical and geometric information of the LiDAR data on building roof were analyzed to segment data and to determine roof shape. The superstructures on the roof were modeled by 3D analytical functions that were derived by least square method. The accuracy of the 3D modeling was estimated using simulation data. The RMSEs were 0.91m, 1.43m, 1.85m and 1.97m for flat, sloped, arch and dome shapes, respectively. The methods developed in study show that the automation of 3D building modeling process was effectively performed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.4 s.346
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• pp.67-74
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• 2006

We present the design of a radiometer in W-band which operates simultaneously with a single antenna configured FMCW radar. We choose a total power radiometer(TPR) which shares an antenna and a front-end with the radar for miniaturizing the system. We separate the radiometer signal from the radar signal using a diplexer in IF band. Because the radiometer has an unwanted transmitter section due to the common use of the MMW front-end with the radar, some additional noise signals caused by the transmitter degrade the sensitivity of the radiometer system. To compensate the degradation of sensitivity, we use matching circuits and a diode detector configured as the voltage doubler. Through some experiments, we have verified that the designed radiometer system has good performances in detecting metal targets tying at several hundred meters.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.1
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• pp.28-34
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• 2005

We review three methods of separating soil respiration into root and soil microbial contribution: (1) component integration, (2) root exclusion, and (3) isotopic method. Among these methods, component integration and root exclusion are most commonly used. Root respiration contribution to soil respiration estimated by the root exclusion method is higher than those by other two methods. Trenching has little environmental disturbances in soil or on surface of site compared to other methods in root exclusion such as root removal and gap formation. Isotopic method has an advantage over other methods because of minimal soil and root disturbances, but this method is costly and requires techniques for the complex analysis. Trenching seems to be an appropriate in situ method for calculating component contributions to soil respiration with minimum disturbances in site. However, the method overestimates the contribution of microbial respiration because of root decay, and realistic results could be obtained by estimating root decay or avoiding large roots in trenched plots.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.971-976
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• 2011

This paper presents the design concepts of a protector for a launch-reconnaissance robot that is to be deployed for data-collection in hazardous regions. The protector protects the reconnaissance robot inside from shock induced during the process of launch, flight, and landing. Since the outer shells of the protector are automatically opened wide by the unlocking mechanism during the landing stage, the reconnaissance robot can easily exit the protector and move around to carry out its mission. We carefully simulated a finite-element model of the protector with the robot and compared the results with the actual dynamic behavior of the system. Shock- response tests using a droptable showed that the proposed protector filled with silicon material successfully attenuated external shock.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.387-397
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• 2009

Physical activity has been increased with increased leasure time. Specifically, due to our mountainous geographical benefits, people actively participate in hiking and climbing as regular daily activities. Thus, more stable and comfortable hiking boots are required to walk on uneven and sloped rocky surface for a long period of time. 5 male subjects were recruited for testing planter pressure patterns of four different conditions(barefoot, classic hiking boot, stiffness 60 and stiffness 65). Tested hiking boots(stiffness 60 and stiffness 65) consists of the multiple pieces of outsoles as they are designed for a better shock absorption. In the results, some positive aspects of stiffness 60 and stiffness 65 such as wide contact area and powerful propulsive patterns at take off was observed compared to the classic hiking boots. Therefore, biomechanical development of hiking related clothes and footwear as well as equipment would be beneficial for people who enjoy hiking to maximize their quality of activities.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.5
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• pp.479-493
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• 2016

LiDAR(Light Detection and Ranging) data acquired from ALS(Airborne Laser Scanner) has been intensively utilized to reconstruct object models. Especially, researches for 3D modeling from LiDAR data have been performed to establish high quality spatial information such as precise 3D city models and true orthoimages efficiently. To reconstruct object models from irregularly distributed LiDAR point clouds, sensor calibration, noise removal, filtering to separate objects from ground surfaces are required as pre-processing. Classification and segmentation based on geometric homogeneity of the features, grouping and representation of the segmented surfaces, topological analysis of the surface patches for modeling, and accuracy assessment are accompanied by modeling procedure. While many modeling methods are based on the segmentation process, this paper proposed to extract key points directly for building modeling without segmentation. The method was applied to simulated and real data sets with various roof shapes. The results demonstrate feasibility of the proposed method through the accuracy analysis.

• Journal of Environmental Impact Assessment
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• v.33 no.2
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• pp.74-83
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• 2024

This study aims to estimate roadkill occurrences and investigate influential factors in Chungcheongnam-do, contributing to the establishment of roadkill prevention measures. By comprehensively considering weather, road, and environmental information, machine learning was utilized to estimate roadkill incidents and analyze the importance of each variable, deriving primary influencing factors. The Gradient Boosting Machine (GBM) exhibited the best performance, achieving an accuracy of 92.0%, a recall of 84.6%, an F1-score of 89.2%, and an AUC of 0.907. The key factors affecting roadkill included average local atmospheric pressure (hPa), average ground temperature (℃), month, average dew point temperature (℃), presence of median barriers, and average wind speed (m/s). These findings are anticipated to contribute to roadkill prevention strategies and enhance traffic safety, playing a crucial role in maintaining a balance between ecosystems and road development.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.723-729
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• 2016

This study compared fin-tube and parallel-flow heat pipes for their sensible heat exchange rate, heat recovery amount, and air-side pressure drop. Tests were done with different refrigerant charging rates of 40-60% vol. and air flow rates of 300-1,400. The sensible heat exchange rate was highest for both types of heat pipes at a working fluid charge of 40% vol. and low flow rate. For the parallel-flow heat pipe, the 60% vol. charge is too high and results in a low sensible heat exchange rate. The reason is that the thicker liquid film of the tube wall deteriorates the heat transfer effect. Hence, the optimal charging rate is 40 to 50% vol. The evaporator heat pipe has a larger air-side pressure drop than the condenser section heat pipe. The reason is considered to be condensation water arising from the evaporator surface. Compared to the fin-tube heat pipe, the parallel-flow heat pipe showed better performance with a working fluid charging rate of 48%, volume of 41%, and an air-side pressure drop about 37%.

• Korean Journal of Remote Sensing
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• v.30 no.1
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• pp.109-126
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• 2014

We improved the Land Surface Emissivity (LSE) data (Kongju National University LSE v.2: KNULSE_v2) over the Communication, Ocean and Meteorological Satellite (COMS) observation region using recent(2009-2012) Moderate Resolution Imaging Spectroradiometer (MODIS) data. The surface emissivity was derived using the Vegetation Cover Method (VCM) based on the assumption that the pixel is only composed of ground and vegetation. The main issues addressed in this study are as follows: 1) the impacts of snow cover are included using Normalized Difference Snow Index (NDSI) data, 2) the number of channels is extended from two (11, 12 ${\mu}m$) to four channels (3.7, 8.7, 11, 12 ${\mu}m$), 3) the land cover map data is also updated using the optimized remapping of the five state-of-the-art land cover maps, and 4) the latest look-up table for the emissivity of land surface according to the land cover is used. The updated emissivity data showed a strong seasonal variation with high and low values for the summer and winter, respectively. However, the surface emissivity over the desert or evergreen tree areas showed a relatively weak seasonal variation irrespective of the channels. The snow cover generally increases the emissivity of 3.7, 8.7, and 11 ${\mu}m$ but decreases that of 12 ${\mu}m$. As the results show, the pattern correlation between the updated emissivity data and the MODIS LSE data is clearly increased for the winter season, in particular, the 11 ${\mu}m$. However, the differences between the two emissivity data are slightly increased with a maximum increase in the 3.7 ${\mu}m$. The emissivity data updated in this study can be used for the improvement of accuracy of land surface temperature derived from the infrared channel data of COMS.