• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.166-173
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• 1985

The multiple ear and tiller line (MET), which was selected from a local maize collection and has been selected for earliness by selfing for five generations, was compared its plant characteristics with four U.S. leading hybrids. 1. The general plant growth was a little retarded by poor soil fertility and structure. 2. The fresh weight of the MET line was about 97.8% of the U.S. check varieties. 3. The dry weight of the MET line was also about 94.5% of the check U.S. hybrids (1,695 kg / 10a.). 4. The tillering and eating habits of the MET line had contributed toward increasing fresh and dry weight of the MET line. 5. The average plant height of the MET line was much less than those of the check varieties, due to the selfing depression manifested by the MET line, (234.7cm. of the MET vs 250.7cm. of the check) 6. Apparent differences of disease resistance was observed among varieties studied. The degree of plants infected with the black stripe mosaic virus was over 20% for the check U.S. hybrids, while less than 5% of the MET line was infected with the disease. 7. The grain yield per 10 a of the MET line was far below the check hybrids due to the inbreeding depression of the MET line. However, the kernel number per unit area of the MET line with small size kernel was much greater than that of the check hybrids. The 100 kernel weight of the MET line was around 10 grams. 8. The average fresh and dry matter weight of the three ($sorghum{\times}sudan$ grass) varieties was very much alike with those of the MET line. 9. In conclusion, the use of the MET line for silage production may have dual adventages because of its low seed price and of its small size kernels, which may reduce the amount of seeds required for planting in an unit area.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.299-310
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• 1994

Intraspecific clonal interactions have important influences on a population structure of the cellular slime mold (CSM). This study was to investigate whether or not evolutionary change in a population could be induced by clonal competition, and to elucidate how various clones in a population evolve in a homogeneous environment of laboratory culture. The characteristic clones of Polysphondylium pallidum which had different resource consumption rates (RCR) and mating types I and II were selected for study. Investigation was conducted for 4 experimental time interval $(T_0-T_4)$; one experimental time interval took almost 10-14 days from inoculation to havest of fruiting bodies. Two sets of 50 clones were cultured from 50 clones at To, and RCR variations of the population were compared between $(T_0\;and\;T_4)$ for each set of clones. Each clone of the CSM had a diverse resource consumption rate, or growth rate, in a homogeneous and limited Cerophyl agar plate despite the passage of 48-56 generations from the beginning of the experiment. Diverse clones with different growth rate could coexist in one site of the homogeneous agar plate as well as heterogeneous soil microenvironment. When there was high clonal diversity of RCR, a clone in a population had high chances to encounter other clones with resultant increased clonal competition. In one set, 26 of 37 clones of mating type I were changed to mating type Il for the 4 experimental time intervals, which indicated that the rate of competitive exclusion among clones during total experiment from $(T_0\;to\;T_4)$ was 0.703. In another set, 31 of 37 clones of mating type I were changed to mating type II , having the rate of competitive exclusion 0.838. The frequency of each of mat~ng types changed by 0.93-1.29% in each successive generation. The competitive exclusion among clones occurred by 1.26-1.75% when approximately $2.6{\times}10^8$ bacterial cells were provided as food and thereafter one generation of myxamoebae of CSM elapsed at room temperature. This finding implicated that in the vegetative state of P, pallidurn there was 1.26-1.75% probabil~ty of evolutionary change per generation changing from one clone to another clone.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.11-19
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• 2011

This research gives weight to establish practical improvement based on analysis of the landscape ecological character and value to realize the importance of small wetland and stream in cultivated areas functioning as a residual landscape element in rural landscape and to deal with ecological depression effectively. The results of summary are as follows. 1) The results of landscape ecological character analysis of wetlands biotop in total of 7 sites, for example, size of surface in site 5 was widely formed about $10,600m^2$, which was assessed satisfactory in terms of slope of waterfront, width of hedgerow, vegetation condition of composition and so on. Also, The number of flexibility showed 2 in site 8-1, the highest, and morphological diversity showed 1.47, the highest. 2) The results of problem analysis of wetland biotop, most of wetlands are analyzed that the width of hedgerow was below 1m. Also, the 4 wetlands in site 8 are appeared that hard to live slope vegetation in there because of slope of waterfronts are above $45^{\circ}$. 3) The results of landscape ecological character analysis of stream in total of 6 sites, for example, width of waterfront in site 4 showed 55m, the widest, and investigated consist of natural ingredients such as soil, rock, gravel. However, width of waterfront in site 2-2 showed 4m, the narrowest, and inclined angle of slope was formed a right angle. 4) The results of problem analysis of stream, width of waterfront hedgerow in site 2-1 showed about 5m, which was very narrower than width of waterfront, and toxic chemicals discharged from near cultivated area without any filtering. Also, all areas of site 2-2 was formed concrete, and was assessed dissatisfactory in terms of capacity of nature purification, flood control, habitat living space because of straight stream. 5) Based on the result above landscape ecological character and problem analysis, main improvement guidelines are set in terms of shape, vegetation, topography in case of wetlands, and which are set in terms of vertical, horizontal structure in case of stream.

• Journal of Environmental Impact Assessment
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• v.26 no.1
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• pp.27-43
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• 2017

The objectives of the study were to evaluate fish compositions, endangered species, community structure, physical habitat, and general water quality for a preliminary environmental impact assessment of Jeokbyeok River on the road construction between two regions. Total number of species and total number of individuals, based on CPUE, were 23 and 1186, respectively. The endangered species (I, II) as the legal protection species were Pseudopungtungia nigra (79 samples) Gobiobotia brevibarba) (5) Gobiobotia macrocephala (2), indicating a requiring of endangered species conservation. In the meantime, exotic species and ecological disturbing species such as Micropterus salmoides and Lepomis macrochirus, were not present, indicating a well conserved area. According to fish community analysis, values of species diversity index were high (range: 0.788 - 1.030), and the dominance index were low (range: 0.097 - 0.183), indicating that the fish community in this area was maintained well without high dominacne by specific species. Also, fish analysis on tolerance guilds and trophic guilds showed that the proportions of sensitive species were largely exceeded the proportions of the tolerant species, while the proportions of insectivore species were largely exceeded the proportions of the omnivore species. This outcome suggests that the ecosystem was well maintained in terms of tolerance and trophic compositions (food chain). Ecological health, based on the multi-metric fish model of Fish Assessment Integrity (FAI), reflected those fish conditions. In other words, values of FAI model averaged 82.4, which means a "good condition" in the criteria of ecological health by the Minstry of Environment, Korea. In addition, general water quality and physical habitat analyses showed that the system was in good condition. Under these conditions, if the road constructions between the two regions happen in the future, inorganic suspended solids may increase in the waterbody, and this may result in indirect or direct influences on the physical habitats and food chain as well as fish compositions, so the ecological protections and prevention strategy from the soil erosion are required in the system.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.2
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• pp.2262-2275
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• 1971

Fourteenes rervoirs maintained by the local land improvement associations in the province of Chullabuk-Do and 20 reservoir maintained by thos in the province of Chullanam-Do, were surveyed in connection with a correction between storage capacity and sediment deposit. In addition to this survey, 3,347 of small reservoir, that lie scattered around in the above-mentioned two provinces were investigated by using existing two provinces were investigated by using existing records pertaining to storage capacity in the office of City and country, respectively. According to this investigation the following comclusions are derived. 1. A sediment deposition rate is high, being about $10.63m^3/ha$ of drainage area, and resulting in the average decreasc of storage capaity by 27.5%. This high rate of deposition coule be mainly attributed to the serve denudation of forests due to disorderly cuttings of trees. Easpecially, in small reservoir, an original average design storage depth of 197mm in irrigation water depth is decreased to about 140mm. 2. An average unit storage depth of 325.6mm as the time of initial construction is decreased to 226mm at present. This phenomena causes a greater shortage irrigation water, since it was assumed that original storage quantity was already in short. 3. Generally speaking, seepage rates through dam abutment intakepipe, etc, are high due to insufficient maintenance and management of reservoir. 4. It is recommended that sediment deposit should be dredged when a reservoir is dry in drought. 5. Farmers usually waste excessive irrigation water. 6. Water saving methods should be practiced by applying only necessary water for growing stage of rice. 7. In are as where water defficiency for irrigation is severe, a soil moisture content should be kept at about 70% by applying water once in several days. 8. Tube wells should be provided so as to exploit ground water and subsurface current below stream bed as much as possible. 9. If an intake weir was constructed, a water collection well should be built for the use in drought. 10. Water conservation should be forced by converting devastated forests contained in the drainage area of reservoir to protected forests so as to take priority of yrefor estation, gully control, the prohibition of disorderly cutting of trees, etc. 11. Collective rice nurseries should be adopted, and it should be recommended that irrigation water for rice nurseries is supplied by farmer themselves. 12. Sediment desposit in reservoir should be thoroughly dreged so as to secure a original design storage capacity. 13. The structure of overflow weir should be automatic so as to freely control flood level and not to increase dam height.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.219-232
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• 2012

The purpose of this study was to find characteristics of $Pinus$ $densiflora$ forests in previous records and cultural landscape regions and to establish a management method for recovery of $P.$ $densiflora$ landscape. A total of 16 landscape paintings were analyzed to study $P.$ $densiflora$ forests in Inwangsan(Mt.) shown in figure data. As a result of analyzing figure data, $P.$ $densiflora$ $forests$ were found to be distributed mainly in the ridge line of east slope side of Inwangsan(Mt.) from landscape paintings of Jung Seon, Jang Si Heung and Gang Hee Un. In order to analyze the landscape of $P.$ $densiflora$ forests shown in photograph data on Inwangsan(Mt.), photographs of Inwangsan(Mt.) since late 1800s were searched and a total of 24 photographs were used for analysis. As a result of photographic analysis, $P.$ $densiflora$ forests were found to be distributed mainly in the low area and ridge line of western slope side of Inwangsan(Mt.). As a result of analyzing the distribution status of 10 cultural heritages of Inwangsan(Mt.), cultural heritages in the mountain were mainly established with rocks and $P.$ $densiflora$ forests as the background and are establishing their landscape not only as a form of cultural heritage but also including the natural landscape in the background. A method of restoring cultural landscape of P. densiflora forests was necessary. As a result of analyzing 26 rock beds of Inwangsan(Mt.), most of $P.$ $densiflora$ forests were distributed nearby rock beds since the past. Among such regions, restoration and management of introduced species in the accumulated soil regions to $P.$ $densiflora$ forests were deemed necessary. As a result of analyzing current vegetation of $P.$ $densiflora$ forest areas of the past, 51.87% of areas maintained $P.$ $densiflora$ forest and 25.80% were changed to artificial forests. Most of low areas of the mountain were turned into urban area (10.16%). Management type for restoration of $P.$ $densiflora$ landscape of Inwangsan(Mt.) was classified into preservation, $P.$ $densiflora$ restoration and maintenance. Preservation management was configured as $P.$ $densiflora$ distribution and rocky area distribution. The targets of $P.$ $densiflora$ restoration were indigenous broad-leaf trees, vegetation areas with introduced species and damaged regions within the mountain. The targets of maintenance were urban area in the low area of Inwangsan(Mt.) and military base at the top of the mountain.

• International Journal of Highway Engineering
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• v.8 no.2 s.28
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• pp.63-74
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• 2006

During the construction of circular underground pipe, the non-proper compaction along the pipe and the decrease of compaction efficiency have been the main problems to induce the failure of underground pipe or facility. The use of CLSM (controlled low strength materials) should be one of the possible applications to overcome those problems. In this research, the full-scaled field test and the numeric analysis using PENTAGON-3D FEM program were carried out for three different cases on the change of backfill materials, including the common sand, the soil from construction site, and the CLSM. From the full-scaled test in field, the use of in-situ CLSM as backfill materials reduced the vertical and lateral deformation of the pipe, as well as the deformation of the ground surface. The main reason for reducing the deformation would be the characteristics of the CLSM, especially self-leveling and self-hardening properties. The measured earth pressure at the surround of the corrugated pipe using the CLSM backfills was the smaller than the other cases, and the absolute value was almost zero. Judging from the full-scaled field test and FEM analysis, the use of CLSM as backfill materials should be one of the best choices reducing the failure of the underground pipes.

• Korean Journal of Ecology and Environment
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• v.49 no.1
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• pp.11-21
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• 2016

Cymbidium kanran Makino is being threatened in its own habitats due illegal collecting and habitat changes by vegetation growth along historical landuse change. In this study, we established habitat restoration model for conservation of C. kanran based on ecological diagnosis. Through exploration to Jeju Island in 2014 and 2015, we identified 27 unknown habitats of C. kanran and in there, abiotic variables and vegetation structure and composition were quantified. Altitudinal distribution of C. kanran was between 200 m~700 m a.s.l. and compared to distribution in 2004, Area of Occupation (AOO) decreased at 82%. Specific habitat affinity was not observed by evenly found in mountain slope and valley and summergreen and evergreen broadleaved forests, but likely more abundant in valley habitats with higher soil and ambient moisture. Total of 96 individual of C. kanran was observed with an average density of $942.6individuals\;ha^{-1}$. The plants showed relatively short leaf length (average=$10.7cm{\pm}1.1cm$) and small number of pseudo bulbs ($1.2{\pm}0.2$). Flowering and fruiting individuals were not observed in field. C. kanran was classified into endangered plant species as CR (Critically Endangered) category by IUCN criteria. Phenotypic plasticity of C. kanran was likely support to sustain in more shaded habitat environment and recent habatat changes to closed canopy and low light availability may exhibit negatively effects to C. kanran's life history. Restoring C. kanran habitat should create open environment as grassland and low woody species density.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.651-660
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• 2007

Acid drainage has been recognized as an environmental concern in abandoned mine sites for long time. Recently, the environmental and structural damage by acid drainage is a current issue in construction sites in Korea. Here, the author introduces the type of damages by acid drainage in construction sites and emphasizes the importance of geoscience discipline in solving the problem. Metasedimentary rock of Okcheon group, coal bed of Pyeongan group, Mesozoic volcanic rock. and Tertiary sedimentary and volcanic rocks are the major rock types with a high potential for acid drainage upon excavation in Korea. The acid drainage causes the acidification and heavy metal contamination of soil, surface water and groundwater, the reduction of slope stability, the corrosion of slope structure, the damage on plant growth, the damage on landscape and the deterioration of concrete and asphalt pavement. The countermeasure for acid drainage is the treatment of acid drainage and the prevention of acid drainage. The treatment of acid drainage can be classified into active and passive treatments depending on the degree of natural process in the treatment. Removal of oxidants, reduction of oxidant generation and encapsulation of sulfide are employed for the prevention of acid drainage generation.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.1
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• pp.28-35
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• 2020

This study aims to analyze restoration techniques of traditional garden sites targeted Korean, Chinese, Japanese palace garden. Restoration was divided into the restore foundation and restore individual elements depending on the residual state of the actual garden features. And derived characteristics that should be considered by conservation techniques. The results are as follows; First, the Wanfo Pavilion Area in Beihai Park where the foundation and foundation stones were restored based on the relevant literature and comparative analysis. The Archaeological Site in Gwanbuk-ri, Buyeo restored only the remaining structures of the ponds, waterways and large buildings among the areas where the excavation was completed. The Second Daigokuden Garden in Heijokyo Palace restored building sites and foundation, and installed poles and piles so that the area of the Second Daigokuden Garden could be known. Second, Donggung Palace and Wolji Pond, Gyeongju where the restoration of individual elements was made, preemptively restored the remains of traditional gardens based on pond garden estuaries and feedbacks that were confirmed through initial excavation. Huanghuazhen Area in Yuanmingyuan Garden was restored based on Western copper plate prints and related records, but further data found after the restoration confirmed that it was restored differently than it is now. East Palace Garden in Heijokyo Palace covered existing features with soil and restored buildings on them. Typical garden elements such as landscape stone and waterways were preserved and exposed. Third, foundation restore is a case in which the base is identified through the current state of the traditional garden site, it is important to restore the foundation first and secure the territoriality when there is no restoration plan for the elevation structure or size of the garden relics. Restoration of individual garden elements requires careful examination of the literature by limiting the restoration of objects that can be restored through the examination of the literature for each element, such as some buildings or facilities in the traditional garden site.