• Korean Journal of Plant Taxonomy
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• v.42 no.2
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• pp.116-125
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• 2012

The distribution, vegetation characteristics and an assessment of the conservation status of the Korea endemic species Coreanomecon hylomeconoides Nakai were investigated to collect biological basic data to formulate a conservation strategy. According to the distribution map of C. hylomeconoides based on the literature, specimen information, and local field surveys, natural populations of C. hylomeconoides are intensively distributed in the Southern regions of the peninsula, around Gyeongsangnam-do and Jeollanan-do. C. hylomeconoides was distributed in the middle and low slope adjacent to a valley. The altitude ranged from 227 m to 744 m, with inclinations of $5-10^{\circ}$. As a result of a vegetation survey within natural populations, a total of 238 taxa were identified from 29 quadrates in 8 natural populations. The importance value of C. hylomeconoides is 25.34% based on the coverage and frequency of the herbaceous layer with in the populations. The species diversity of the occurrence of the species in 8 natural populations was 1.52, while the averages of species evenness and the dominance values were calculated to be 0.83 and 0.17, respectively. As a result of assessing the conservation status through IUCN Red List criteria, C. hylomeconoides was evaluated as Near Threatened (NT). Conservation strategies are also discussed for the sustainable conservation of C. hylomeconoides.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.180-187
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• 2013

The dinger in solar generation is the amount of sunlight which the solar cells absorb. Various types of solar trackers, which rotate themselves in order to make the solar cells face the sun as much as possible, have been developed, and especially the method of tracking with two axes has greatly contributed in increasing the generation amount at work sites. Among theses 2-axis solar trackers, the inclination-dependent 2-axis solar tracker are widely utilized for its advantages of requiring less initial investment and easy maintenance due to a solid structure. However, the drawback is that the generation efficiency is relatively low because of the structural restriction that limits the rotation angle, thus making it less efficient when tracking the sun. This paper proposes a method to increase the generation efficiency of the inclination-dependent 2-axis solar tracker. It also contains the derived equations needed for precise controlling along with a method to keep tracking with the other axis even when one has reached its angle limit. To confirm that the proposed method increases the amount of incidence onto the solar cells, formulas needed for operation on the proposed method and tracking the exact position of the sun are derived, and applying this to the quarterly data of Korea Astronomy and Space Science Institute it shows maximum over 11.1% more incidence compared to existing methods.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.145-181
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• 2013

General aviation is an integral part of civil aviation and involves the widest range of aviation segments except commercial aviation. Featured with different operational procedures and practices to satisfy the economic needs and safety requirements of a sovereign state, general aviation tends to be regulated by an individual state. The last three decades have seen exponential growth of commercial air transport in China, but its general aviation sector has remained disproportionally underdeveloped. With the deepening of the reform of low-altitude airspace, the sector is poised for a radical change and rapid growth. However, legislation governing general aviation activities in China is distorted causing inconsistency and confusions in their application and implementation. This paper aims to analyse China's prevailing legislation regulating general aviation activities. It first discusses the various definitions adopted by ICAO and its member states and reviews the development of general aviation in the US, EU, Australia and China. It then examines the sources of China's general aviation laws, e.g. Chicago Convention and its annexes, and Chinese domestic legislature which covers legislation, laws, directives, rules and procedures. The paper continues to analyse and establish the deficiencies of its prevailing legal framework by pointing out the following: variation of definitions in different regulations, inconsistency of principles in existing laws and regulations, legal vacuum concerning government subsidy, environment protection, safety and security, and other operational areas such as aerial club, sightseeing, and search and rescue. In this process, the paper argues that a coherent, consistent and systematic legal framework is required in order to ensure fair competition and safety for a healthy, progressive and sustainable general aviation growth. Suggestions for rectification and improvement are proposed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.1
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• pp.10-18
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• 2017

Korean Red Pine (Pinus densiflora) has been protected and used as the most ecologically and socio-culturally important tree species in Korea. However, as dieback of Korean red pines has occurred in the protected area of the forest genetic resources. The aims of this study is to identify causes for dieback of pine tree by investigating topographical characteristics of pine tree dieback and its correlation to meteorological factors. We extracted the dead trees from the time series aerial images and analyzed geomorphological characteristics of dead tree concentration area. As a result, 1,956 dead pine trees were extracted in the study region of 2,600 ha. Dieback of pine trees was found mostly in the areas with high altitude, high solar radiation, low topographic wetness index, south and south-west slopes, ridgelines, and high wind exposure compared to other living pine forest area. These areas are classified as high temperature and high drought stress regions due to micro-climatic characteristics affected by topographic factors. As high temperature and drought stress are generally increasing with climate change, we can evaluated that a risk of pine tree dieback is also increasing. Based on these geomorphological characteristics, we developed a pine tree dieback risk map using Maximum Entropy Model (MaxEnt), and it can be useful for establishing Korean red pine protection and management strategies.

• Journal of the Korean Geographical Society
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• v.45 no.4
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• pp.431-443
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• 2010

The morphometric characteristics of 13 alluvial fans in the southern parts of the Korean Peninsula are studied and relationships between their distributions and causes are discussed by comparing them with 690 alluvial fans in Japan, Taiwan and the Philippines. The relationships between the surface gradient of alluvial fans and source basin area, the surface gradient and the relief ratio of the source basin, and the source basin area and the relief ratio were investigated. The alluvial fans in South Korea have typical characteristics of the Asian fans, although their frequency and density are relatively low, and the size and the relief ratio of their source basins are relatively small and steep, respectively. Moreover 36 major Korean river basins without alluvial fans tend to have lower altitude and relief ratios. Contrary to the argument by Blair and McPherson, the natural depositional gaps on the gradient of alluvial fans were not found. The Gyeongju alluvial fan is probably a fluvial fan with gentle gradient, whereas the other Korean fans seem to be debris-flow related on the base of their gradients.

• The Journal of Engineering Geology
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• v.1 no.1
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• pp.19-37
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• 1991

The geology of the northwestern Cheju Island consist of Pleistocene to Holocene volcanic rocks which could be devided into basalt layers, the Sungsan Formation composed mainly of volcaniclastic debris exposed along the shoreline, and more than 30 cinder cones. Columnar joints and vesicles are dominant in the basalts of the Pyeosunri and the Sihungri basalt Formations. Volcaniclast and clay layers are intercalated in basaltic layers. When volcaniclast of the interlayers would be swept away by ground water and some caves of channel shape would be formaed. Overlying lavas cracked by columnar joints could be easily destroyed, collapsed and/or sunk. Geomechananical nature of the rocks such as strength may be controlled by the vesicularity(size, shape, and orientation of the vesicles) of the rocks. On the basis of vesicularity as a factor of strength, the effective strength ratio(Ke) could be calculated as Ke=0.3-0.72, in which the smaller Ke value reflects the lower in internal stress. In the studied area, the strength of the rocks tends to decrease as increasing in altitude of provenance of the rocks. The rocks in the area show relatively low values in angle of failure strength($\phi$) ranging from 10$^{\circ}$ to 30$^{\circ}$. In conclnsion, the rocks in question, majority of which the critical value exceeds 0.33, belong to the unstable rocks in the aspect of engineering geology.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.1
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• pp.30-36
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• 2001

Schisandra nigra Max. has been cultivated far a medical use as well as food. It is an endemic species which has a unique habitat at the altitude of 600-1,400 m in Cheju island. In this study, three natural populations of S. nigra were investigated by using of starch-gel electrophoresis to determine the extent and distribution of genetic diversity. Except 2 monomorphic locus (Mdh-2 and Pgi-1), 4 of the 6 isozyme locus (Idh, Mdh-2, Mnr, and Pgi-2), verified from 4 isozymes, revealed polymorphism in the three populations of S. nigra. The mean number of allele per locus was 1.7 and the percentages of polymorphism loci were 38.9% at 95% level and 50% at 99% level respectively. The observed and estimated heterozygosities were 0.141 and 0.147 respectively. Although plants which were in the face of crisis and distributed in the restricted area, have been known to the very low degree of genetic variation, S. nigra showed higher genetic variation than others. Genetic variation was mostly allocated within population and individuals than that among populations. The result of Wright's F analysis estimates of $F_{IT}$ and $F_{IT}$ showed that S. nigra population revealed Hardy-Weinberg steady state.

• Journal of the Korean Society of Groundwater Environment
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• v.7 no.3
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• pp.116-124
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• 2000

Geochemical and isotopic analyses were carried out to investigate hydrochemical characteristics, source of carbon species in the carbonated waters in South Korea. Most Korean carbonated waters from different geologic settings are characterized by a Ca-HCO$_3$type with a relatively low pH range from 5.3 to 6.3 (avg. 6.0). The concentrations of cations and anions in the carbonate waters are in the order of Ca$^{2＋}$>Na$^{＋}$>Mg$^{2＋}$>Si$^{4＋}$>Fe$^{2＋}$>K$^{＋}$ and HCO$_3$$^{－}$>SO$_4$$^{2－}$>Cl$^{－}$, respectively. The HCO$_3$$^{－}$ ion is more enriched in the carbonated water from the sedimentary rock and granitic rock of Mesozoic age in the Gyungsang basin(GII) and the Precambrian metamorphic rock and Jurassic granitic rocks of the Gyunggj massif in the Gangwon province(GⅠ) than those of the meta-sedimentary rock and granite in the Ogcheon zone(GⅢ). Based on the oxygen and hydrogen isotopic data, the carbonated waters are derived from the meteoric water, showing apparent latitude and altitude effects. The $delta$$^{13}$C values of carbon species in the carbonated water are in between -6.23 and 0.0 $textperthousand$, suggesting inorganic source of carbon originated from the carbonate mineral and carbonate rock in the aquifer.

• Journal of Wetlands Research
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• v.15 no.1
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• pp.71-78
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• 2013

An exceptional case of inhabitation of a Sphagnum sp. was firstly confirmed at abandoned paddy terrace (APT) wetland in Ansan. Water sampling for analyzing of physicochemical conditions including nutrients such as NP, $Ca^{2+}$ and $Mg^{2+}$ was performed and the vegetation map for distribution of Sphagnum sp., topographical map, and flora list for companion species were made at field in June 2011. From the results, the Sphagnum sp. in the study site was identified as S. palustre and it covered about 8% of the wetland cover of 3,200 $m^2$. Most distributions of S. palustre were observed at tussock structures as micro-topography by sedges and grasses within a wetland (74%) and the shaded slope area under Pinus densiflora's canopy in wetland boundary (26%). Despite that APT in Ansan is relatively lower wetland in altitude than high moors, the contents of calcium ($0.45{\pm}0.2$) and magnesium ($1.48{\pm}0.6$) ion which are critical limiting factors for Sphagnum spp. were very low levels as well as NP ($PO_4$-P, $0.02{\pm}0.0$; $NO_3$-N, $0.25{\pm}0.3$; $NH_4$-N, $0.06{\pm}0.1$) and it could enable the inhabitation of S. palustre in lower APT.

• Journal of Korean Society on Water Environment
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• v.22 no.3
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• pp.431-436
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• 2006

This study was conducted in the summer of 2005 in Shindong-myeon, Chuncheon-si, Gangwon-do to assess the quality of drinking water and to evaluate their potential pollutants. Ninety four water samples were collected from three classes of water supplies such as simple piped water, supplied own water and others (Supplied local water). Most residents used simple piped water (72.63%). 31.25% residents thought the water quality was bad and landfill was the main source of pollution that affected water quality. To correspond this perception, water quality was measured according to Drinking Water Quality Standard. The general bacteria, coliforms, and $NO_3-N$ exceeded the standard but the water qualities in these four areas were suitable for Drinking Water Quality Standard. The simple piped water showed low mean concentration of excess rate compared to supplied own piped water except general bacteria. Hardness, pH, and $NO_3-N$ showed significantly higher effects on drinking water quality. To evaluate the effect of effluent from landfill, water quality was measured according to distance and altitude. However, there was no effect of landfill effluent. To find out the effect of rainfall, we compared water quality of the year 2003 with that of 2005. The result showed significant differences in hardness and $NO_3-N$ concentration. This study confirmed that $NO_3-N$, coliforms, and general bacteria are main pollutant of water supply in rural community. Therefore, it is necessary to regularly maintain simple piped water supply, supplement sewer facilities, and educate residents about public health risk associated with drinking water in rural area.