• Clean Technology
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• v.10 no.1
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• pp.37-45
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• 2004

This study examined the separation characteristics of some of the most commonly used disperse, reactive and acid dyes by nanofiltration membrane. The chemical characteristics of three major dye solutions such as chemical oxygen demand, total nitrogen, total organic carbon, color, suspended solids, total dissolved solids, conductivity were investigated in this work. Experiments showed that the types of dye had a significant effect on both permeate flux and rejection efficiencies mainly due to the differences among their chemical structures and natures. Especially, the nanofiltration of reactive dye solutions showed higher permeate flux, lower total dissolved solid rejection efficiency and higher organics rejection efficiency than those of disperse dye solutions.

• Journal of Digital Convergence
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• v.14 no.10
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• pp.173-181
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• 2016

The objective of this study is to subdivide the tactical considerations (METT+TC; Mission, Enemy, Terrain & Weather, Troops available, Time available, Civil considerations) through Delphi method and prioritize those via AHP (Analytic Hierarchy Process). Though it has been taken for granted that the tactical considerations were inevitable for decision making relating to military operations, their segmentation and priority have not been studied sufficiently in military. The data for Delphi method and AHP were based on interview with military experts and questionnaires answered by those. Six tactical considerations were segmented into 34 sub-considerations by Delphi, and Six tactical considerations and 34 sub-ones were prioritized through AHP in attack and defense aspects. If the research results will be embedded into database of automatic command and control system (e.g. ACTIS; Army Tactical Command Information System), effective decision-making process will get easier and faster.

• Atmosphere
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• v.25 no.1
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• pp.51-66
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• 2015

This study was conducted to perform various sensitivity experiments using WRF (Weather Research and Forecasting) model in order to determine the effects of terrains of the Korean Peninsula and the land-sea thermal contrast on the formation and development of the convergent cloud band for the cases of 1 February 2012. The sensitivity experiments consist of the following five ones: CNTL experiment (control experiment), and TMBT experiment, BDMT experiment and ALL experiment that set the terrain altitude of Taeback Mountains and Northern mountain complex as zero, respectively, and the altitude of the above-mentioned two mountains as zero, and LANDSEA experiment that set to change the Korean Peninsula into sea in order to find out the land-sea thermal contrast effect. These experiment results showed that a cold air current stemming from the Siberian high pressure met the group of northern mountains with high topography altitude and was separated into two air currents. These two separated air currents met each other again on the Middle and Northern East Sea, downstream of the group of northern mountains and converged finally, creating the convergent cloud band. And these experiments suggested that the convergent cloud band located on the Middle and Northern East Sea, and the cloud band lying on the southern East sea to the coastal waters of the Japanese Island facing the East Sea, were generated and developed by different dynamical mechanisms. Also it was found that the topography of Taeback Mountains created a warm air advection region due to temperature rise by adiabatic compression near the coastal waters of Yeongdong Region, downstream of the mountains. In conclusion, these experiment results clearly showed that the most essential factor having an effect on the generation and development of the convergent cloud band was the topography effect of the northern mountain complex, and that the land-sea thermal contrast effect was insignificant.

• KIISE Transactions on Computing Practices
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• v.24 no.2
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• pp.77-81
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• 2018

Many studies that improve the efficiency of data collection and a network's lifetime by using a mobile sink have been conducted using wireless sensor networks. If a drone is used as a mobile sink, the drone can collect data more efficiently than can existing mobile sinks operating on the ground because the drone can minimize the effects of obstacles and the terrain. In this paper, we propose a rendezvous node selection scheme which considers estimated drone's trajectory and data collection latency of sensor networks for reliable data collection, when a drone whose trajectory is not predetermined works with terrestrial wireless sensor networks. A selected rendezvous node on the ground collects data from the entire network and it sends then collected data to the drone via direct communication. We also verify that the proposed scheme is more reliable than previous schemes without considering the drone's trajectory and data collection latency.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.767-775
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• 2016

Wood properties are affected by environmental factors such as soil, topography, rainfall, and climate change. The physical and mechanical properties of Quercus glauca were analyzed in order to investigate the relationship between wood properties and forest stand characteristics related to regions and forest origins. Physical and mechanical properties of wood were influenced by region. And no significant difference was observed between natural and artificial forests with respect to wood quality properties. Therefore, these findings are expected to be useful as fundamental data for silviculture practices of these species for wood quality.

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.439-457
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• 1993

The present study was undertaken to classify and describe the forest vegetation on Imha-dam area, located at the northern part of Kyungsang-pookdo, Korea by the phytosociological method of the Z-M school. The field investigations were carried out in 60 plots around the dam area from May 1, 1991 to October 10, 1992. The vegetation data obtained were classified by the table comparison method. As a result, the following vegetation units were recognized: A. Pinus densiflova community A-a. Miscanthus sinensis group A-b. Carex humilzs group A-c. Typical group B. Quercetum variabili-serratae Kobayashi, Muranaga et Takeda 1976 C. Robinin pseudo-acacia-Conzmeli~ta comnzultis community D. Larix leptolepis community The vascular plant species of these forest communities consist of 63 families, 144 genera, 191 species and 30 varieties. Also the relationship of the vegetation units with their environments such as altitude, slope, topography and soil condition was discussed here. On the basis of the floristic composition, life-form spectrum and soil analysis, a sere for the forest vegetation was proposed as follows: Rohinia pseitdo-acacia-Conz~neli~za communis community and Larix leptolepis community $\rightarrow$ Pinus densiflora community $\rightarrow$ Quercetunz variahili-serratae $\rightarrow$ Quercus mongolica community. Lastly, relating to the nature conservation of dam area, some of plans were discussed.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.1
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• pp.183-194
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• 2010

A suitability analysis for marine afforestation was carried out on physical items based on slop rate, bottom sediment, light intensity, velocity, and wave at north Geomoon waters in Korea. The data from each physical item were changed to a GSDM (Gridded Spatial Distribution Map) using Kriging interpolation. A GSDM grid includes information, and each grid was given a SI (suitability index) of 3 grades(SI of first suitability was 100, SI of second suitability was 50, and non-suitability had no SI). According to the analysis results of all overlaid GSDM, first suitability had 500 SI, and suitability area was 0.25ha. Second and third suitability had 400~450 SI, and suitability area was 2.36ha, 1.80ha, respectively. Therefore, the results suggest that reefs installed for marine afforestation should be anti-slip types against steep slope, and the target species need to include algae with low compensation light intensity in second and third suitability.

• The Korean Journal of Ecology
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• v.23 no.3
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• pp.255-266
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• 2000

생물권보전지역으로 지정된 점봉산의 온대낙엽수림(참나무 성숙림)에서 임상초본식물의 공간분포를 정량화하고, 이들의 공간분포에 미치는 미소환경요인의 영향을 파악하였다. 대부분의 임상초본식물들은 영구 방형구내 미소지소간에 큰 변이를 나타내었다. 초봄에 출현하는 임상초본식물중 공간의존도가 높은 식물은 현호색, 애기나리 및 노랑제비꽃이었고, 가을에 출현하는 임상초본식물중 공간의존도가 높은 식물은 벌깨덩굴, 쌀새 및 도라지모시대이었다. 초봄에 출현하는 홀아비바람꽃과 얼레지 그리고 가을에 출현하는 도라지모시대와 쌀새의 공간의존거리가 상대적으로 짧은 편이었다. 초봄에 출현하는 노랑제비꽃, 애기나리 및 얼레지는 관목이 적고, 낙엽층이 얇으며,토심이 깊고, 토양수분함량, 유기물함량 및 염기성양이온함량이 상대적으로 적은 생육지를 선호하였고, 애기앉은부채 와 현호색은 관목이 밀집하고, 낙엽층이 두꺼우며, 토심이 얇고, 유기물함량, 토양수분함량 및 영양염류함량이 높은 생육지를 선호하였다. 오리방풀은 빛조건이 좋고, 낙엽층이 두꺼우며, 토양수분함량과 영양염류가 풍부한 생육지를 선호하였고, 단풍취, 대사초, 개별꽃, 참취, 쌀새 및 도라지모시대는 토심이 깊고, 낙엽층이 얇으며, 토양수분함량과 영양염류함량이 상대적으로 적은 생육지를 선호하였다. 본 참나무 성숙림에서 토양수분함량, 유기물함량 및 영양염류함량은 바람, 미소지형 및 관목의 밀집정도에 의해 공간적으로 재배치되는 낙엽층 두께에 의해 영향을 받고 있기 때문에 초봄과 가을에 관찰되는 임상초본식물의 공간분포는 낙엽층의 불균등한 분포에 의해 가장 큰 영향을 받고 있는 것으로 추정되었다.

• Journal of the Korean Data and Information Science Society
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• v.28 no.5
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• pp.1133-1144
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• 2017

Cluster analysis with meteorological data allows to segment meteorological region based on meteorological characteristics. By the way, meteorological observed data are not adequate for cluster analysis because meteorological stations which observe the data are located not uniformly. Therefore the clustering of meteorological observed data cannot reflect the climate characteristic of South Korea properly. The clustering of $5km{\times}5km$ gridded data derived from a numerical model, on the other hand, reflect it evenly. In this study, we analyzed long-term grid data for temperatures and precipitation using cluster analysis. Due to the monthly difference of climate characteristics, clustering was performed by month. As the result of K-Means cluster analysis is so sensitive to initial values, we used initial values with Ward method which is hierarchical cluster analysis method. Based on clustering of gridded data, cluster of meteorological stations were determined. As a result, clustering of meteorological stations in South Korea has been made spatio-temporal segmentation.

• Journal of Environmental Impact Assessment
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• v.7 no.1
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• pp.49-61
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• 1998

Zoning areas within national parks in Korea are classified into Natural Preservation Zone(NPZ). Natural Environment Zone(NEZ), Settlement Zone(SZ) and Mass Facility Zone(MFZ) based on the Natural Park Act Large-scale development which might cause permanent destruction of natural resources are being done in NEZ which covers 90% of the total natural park area. Thus it is necessary to examine National Park Act which refers the authorized criteria and development activities of NEZ. However, the current environmental impact statement(EIS) does not cover the full impact of the development inside the national park area. Based on these concepts, the study examines the appropriate resources to distinguish the NPZ and NEZ in Mt. Teogyu National Park, then compare the distribution of resource characteristics between two area by using GIS. Through this study, the conclusions are as follows; (1) In terms of scenic resource analysis, the current NPZ does not meet the criteria on the National Park Act Rather, most of the resources which should be located within the NPZ are located within the NEZ. (2) In terms of elevation analysis, Mt. Teogyu National Park, most of NPZ are located on high altitude which is more than l,200m above the mean sea level. Therefore, it shows the elevation is the only criteria for distinguishing NPZ and NEZ. (3) In terms of Degree of Green Naturality(DGN), the second forest areas, the eighth grade of DGN in Mt. Teogyu National Park are distributed much more in the NEZ than NPZ. (4) After examining five factors - scenic resources, elevation, slope and DGN, vegetation- it was found out that zoning of Mt. Teogyu National Park is not adequatly designated. Zoning of national parks should be accomplished based on the precise inventory of the current resources.