• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.59
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• pp.105-118
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• 2000

The rise in population and the increase of urbanization and industrial growth has resulted in an ever-increasing volume of municipal solid waste that must be regularly collected, transported, and ultimately disposed of. Therefore, over the last decade the public, commercial and legislative awareness of environmental issues has been increased dramatically on earth particularly some industrial countries which has a shortage of landfill capacity. A quality, cost and delivery lead-time are usually considered as the competitive factors for each industry. However, the concepts of environmental issue are emerging common terms and concerns more seriously. More attention than ever is being focused on the recycling and source reduction techniques to reduce the total volume of waste. Unfortunately, however, a shortage of landfill capacity and increasing disposal cost requests a fundamental solution about the environmental issue. That is the remanufacturing which allow manufacturers to minimize waste, production cost and to turn end-of-life product into a profitable product. The objectives of this research were to growth the remanufacturing system by suggesting issues and implementation methods for the remanufacturing. In order to accomplish these objectives, we introduced backgrounds of appearance and benefits of the remanufacturing.

• Journal of the Korean Geophysical Society
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• v.7 no.3
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• pp.161-170
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• 2004

Examples of GPR survey results at a variety of archaeological sites are presented. Several new analyses which include static corrections for the tilt of the GPR antenna are shown for imaging of burial mounds with significant topography. Example archaeological site plans developed from GPR remote sensing of Roman and Japanese sites are given. The first completely automated GPR survey, using only Global Positioning Satellite navigation to create 3D data volumes, is employed for a site in Louisiana to detect lost graves of the Choctaw Indian Tribe.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2385-2387
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• 2002

종래 도로상의 차량검지기들은 기후변화 및 도로환경의 변화, 물리적인 변화에 영향을 받아 감지의 정확도가 떨어져 신뢰도 높은 교통정보를 생성하기가 어렵고, 제품의 가격이 고가이며, 설치 및 유지, 보수에 많은 비용과 인력이 요구된다. 본 연구에서는 종래의 차량 검지기가 지니는 문제점들을 해결하여 어떠한 환경하에서도 신뢰성 있는 차량 주행정보를 제공하며 동시에 유지, 보수 비용이 저렴한 검지기로서 AMR(Anisotropic Magneto-Resistive) 센서를 이용하여 도로상의 차량 이동에 따른 지구자기장(Earth Magnetic Field) 변화를 감지하고 차량의 이동상태를 파악하는 교통량 계측장치를 제시한다.

• Journal of Soil and Groundwater Environment
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• v.27 no.4
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• pp.49-62
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• 2022

The magnesium and iron-based layered double hydroxide (Mg-Fe LDH) was synthesized by the co-precipitation process and the bead type LDH (BLDH, 5~6 mm in diameter) was manufactured by using the Mg-Fe LDH and the starch as a binder. To evaluate the feasibility of the BLDH as the As stabilizer in the soil, various experiments were performed and the As stabilization efficiency of the BLDH was compared to that of powdered type LDH (PLDH, <149 ㎛ in diameter). For the As sorption batch experiment, the As sorption efficiency of both of the PLDH and the BLDH showed higher than 99%. For the stabilization experiment with soil, the As extraction reducing efficiency of the PLDH was higher than 87%, and for the BLDH, it was higher than 80%, suggesting that the BLDH has similar the feasibility of As stabilization for the contaminated soil, compared to the PLDH. From the continuous column experiments, when more than 7% BLDH was added into the soil, the As stabilization efficiency of the column maintained at over 91% for 7 pore volume flushing (simulating about 21 months of rainfall) and slowly decreased down to 64% after that time (to 36 months) under the non-equilibrium conditions. Results suggested that more than 7% of BLDH added in As-contaminated soil could be enough to stabilize As in soil for a long time. The main As fixation mechanisms on the LDH were also identified through the X-ray fluorescence (XRF), the X-ray diffraction (XRD), and the Fourier transform infrared (FT-IR) analyses. Results showed that the LDH has enough of an external surface adsorption capacity and an anion exchange capability at the interlayer spaces. Results of SEM/EDS and BET analyses also supported that the Mg-Fe LDH used in this study has sufficient porous structures and outer surfaces to fix the As. The reduction of carbonate (CO₃^2-) and sulfate (SO₄^2-) anions in the LDH after the reaction between As and the LDH was observed through the FT-IR, the XRF, and the XRD analyses, suggesting that the exchange of some of these anions with the arsenate (H₂AsO₄^- or HAsO₄^2-) occurs at the LDH interlayers during the stabilization process in soil.

• Journal of the Korean earth science society
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• v.35 no.2
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• pp.104-114
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• 2014

The variation of acidity, conductivity, and ion components in precipitation depending on the dominant wind direction was investigated from January, 2009 to December 2009 in Busan, Korea. Both southwesterly and northeasterly winds were dominant in Busan area. The volume-weighted mean acidity showed pH 7, and the high conductivity indicated 200 ${\mu}scm^{-1}$ in westerly wind. The volume-weighted mean equivalent concentration showed higher value of $K^+$ and $Cl^-$ in all wind directions. The composition ratio of $NO{_3}^-/SO{_4}^{2-}$ showed over 3 in northerly wind. The neutralization factors have been found to have higher value for potassium ion in northeasterly, easterly, southwesterly, and westerly winds compared with different wind directions, which indicated significant neutralization of acidic components over the region by potassium. Also, the concentration of sea salt has been found over 800 ${\mu}sm^{-3}$ in northeasterly and southwesterly winds. Air masses passing through Manchuria, Inner Mongolia plateau, China, and Russia in spring, autumn, and winter covered Busan, Korea in northerly, westerly, and northwesterly winds. However, air masses passing through the ocean in summer covered Busan, Korea in easterly, northeasterly, and southwesterly winds. Therefore, the variation of acidity, conductivity, and ionic components contained in precipitation shows each seasonal characteristics with prevailing wind systems between the continental and coastal area in Busan, Korea.

• Ocean and Polar Research
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• v.43 no.4
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• pp.307-320
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• 2021

Udo Rhodolith Beach is a small-scale, mixed sand-and-gravel beach embayed on the N-S trending rocky coast of Udo, Jeju Island, South Korea. This study analyzes the short-term topographic changes of the beach during the extreme storm conditions of four typhoons from 2016 to 2020: Chaba (2016), Soulik (2018), Lingling (2019), and Maysak (2020). The analysis uses the topographic data of terrestrial LiDAR scanning and drone photogrammetry, aided by weather and oceanographic datasets of wind, wave, current and tide. The analysis suggests two contrasting features of alongshore topographic change depending on the typhoon pathway, although the intensity and duration of the storm conditions differed in each case. During the Soulik and Lingling events, which moved northward following the western sea of the Jeju Island, the northern part of the beach accreted while the southern part eroded. In contrast, the Chaba and Maysak events passed over the eastern sea of Jeju Island. The central part of the beach was then significantly eroded while sediments accumulated mainly at the northern and southern ends of the beach. Based on the wave and current measurements in the nearshore zone and computer simulations of the wave field, it was inferred that the observed topographic change of the beach after the storm events is related to the directions of the wind-driven current and wave propagation in the nearshore zone. The dominant direction of water movement was southeastward and northeastward when the typhoon pathway lay to the east or west of Jeju Island, respectively. As these enhanced waves and currents approached obliquely to the N-S trending coastline, the beach sediments were reworked and transported southward or northward mainly by longshore currents, which likely acts as a major control mechanism regarding alongshore topographic change with respect to Udo Rhodolith Beach. In contrast to the topographic change, the subaerial volume of the beach overall increased after all storms except for Maysak. The volume increase was attributed to the enhanced transport of onshore sediment under the combined effect of storm-induced long periodic waves and a strong residual component of the near-bottom current. In the Maysak event, the raised sea level during the spring tide probably enhanced the backshore erosion by storm waves, eventually causing sediment loss to the inland area.

• Proceedings of the KSRS Conference
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• v.1
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• pp.512-515
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• 2006

Forest stand height and volume are important indicators for management purpose as well as for the environmental analysis. Shuttle Radar Topography Mission (SRTM) is backscattered over forest canopy and DSM can be acquired from such scattering characteristic, while National Elevation Dataset (NED) provides bare earth elevation data. The difference between SRTM and NED is estimated as tree height, and it is correlated with forest parameters, it is correlated with forest parameters, including average DBH, Trees per acre, net BF per acre, and total Net MBF. Especially, among them, net Board Foot(BF) per acre is the index that well represents forest volume. The Project site was Douglas-fir dominating plantation area in the western Washington an the northern Oregon in the U.S. This study shows a relationship of high correlation between the forest parameters and the product from SRTM, NED, and ETM+. This research performs multi regression analysis and regression tree algorithm, and can get more improved relationship between several parameters.

• Geophysics and Geophysical Exploration
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• v.6 no.2
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• pp.101-107
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• 2003

3D seismic travel-time tomography algorithm baled on Fresnel volume was developed and its feasibility was investigated by the numerical experiments. To testify the field applicability of the developed algorithm, frequency characteristics and way coverage of the crossholel seismic raw data were investigated and 3D velocity tomogram cube with about 8m spatial resolution was obtained. When compared this 3D velocity cube with the conventional 2D ray tomogram, two results were matched well. We concluded that 3D seismic tomography algorithm developed in this study has enough potential to the field application.

• Korean Journal of Remote Sensing
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• v.22 no.5
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• pp.427-431
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• 2006

Forest stand height and volume are important indicators for management purpose as well as for the environmental analysis. Shuttle Radar Topography Mission (SRTM) is backscattered over forest canopy and DSM can be acquired from such scattering characteristic, while National Elevation Dataset (NED) provides bare earth elevation data. The difference between SRTM and NED is estimated as tree height, and it is correlated with forest parameters, it is correlated with forest parameters, including average DBH, Trees per acre, net BF per acre, and total Net MBF. Especially, among them, net Board Foot(BF) per acre is the index that well represents forest volume. The Project site was Douglas-fir dominating plantation area in the western Washington an the northern Oregon in the U.S. This study shows a relationship of high correlation between the forest parameters and the product from SRTM, NED, and ETM+. This research performs multi regression analysis and regression tree algorithm, and can get more improved relationship between several parameters.

• Magazine of the Korean Society of Agricultural Engineers
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• v.25 no.4
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• pp.29-37
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• 1983

This study was carried out not only to prepare available materials that can be utilized in basic planning of irrigation reservoirs, but also to contribute to the study on countermeasures for reasonable irrigation water development in Korea in the future, through the investigation for the structural characteristics of reservoirs and their change trend by an epoch. During this study 123 sites of sample reservoirs were analysed in their dimensions of physical constituent factors. The physical characteristics and their change trends revealed by this study are summarized as follows: 1. For the irrigation earth dam in Korea the correlation between dam volume (v) and dam height & length (H$^2$L) can be described as the formula of v=1. 434H2L~17, 300 (r=0. 933), from which embankment amount is assumed to be quickly estimated under determined dam height and length of the proposed reservoir. 2. The ratio of dam volume to dam height & length ranges approximately from 0.5 to 3 (1.7 in average), that of storage capacity to dam volume 2 to 10 (8.4 in average), that of irrigation area to full water surface area 5 to 20 (13 in average) and that of catchment area to irrigation area 2 to 5 (4 in average). Though correlation between dam volume and dam height & length is high, that between others is relatively low. 3. Average storage depth ranges approximately from 4m to l0m (6.6m in average), unit storage capacity 0. 4m to 0. 8m (0.54 in average) and shape factor of dam 5 to 20 (10.5 in average). 4. The more recently planned the reservoirs were, the less storage capacity, dam volume, full water surface and dam shape factor they have. 5. The more recently planned the reservoirs were, the larger storage depth and unit storage capacity they have.