• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.1-7
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• 2020

As of 2018, Steel slag was generated approximately 24.23 million tons. Howeve, except blast furnace slag, steel slag is a typical by-product which does not have a clearly defined purpose in recycling. Thus, countries around the world are putting great efforts into developing a purpose for the recycling of steel slag. The vast habitat foundation of marine life has been destroyed due to recent reckless marine development and environment pollution, resulting in intensification of the decline of marine resources, and a solution to this issue is imperative. In order to propose a method to recycle large amounts of by-product slag into a material that can serve as an alternative to natural aggregate, the engineering properties and applicability for each mixing factor of environment friendly porous concrete as a material for the composition of seawater purification were in this study. Regarding the nutrient elution properties, it was clear that the nutrients continuously flowed out up to an immersion time by 8 months in natural seawater; the nitrogenous fertilizer displayed excellent elution properties in this regard.

• FLOWER RESEARCH JOURNAL
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• v.18 no.2
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• pp.110-116
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• 2010

This text was analyzed and investigated the vegetation and floristic composition by ordination and classification of phytosociological method, to evaluate the species composition and community structure of Cymbidium goeringii group in Korean islets. In habitat of 33 plots, the mean altitude was 65.9m, the direction was the southeast slope, the mean slope was 7.9%. The coverage of Cymbidium goeringii was 4.5%. The appearing plants with the Cymbidium goeringii was the total 102 taxa, and it was the kind of trees 68 taxa (66.7%), herbs 34 taxa (33.3%), evergreen plants 36 taxa (35.3%) and deciduous plants 66 taxa (64.7 %) respectively. The frequency of appearing plant was the highest in the Eurya japonica (48.5%), followed by Pinus thunbergii (45.5%), Smilax china (36.4%), Carex lanceolata (33.3%), Hedera rhombea (33.3%), Machilus thunbergii (30.0%), Styrax japonicus (30.3%) and Pinus densiflora (27.3%), respectively. The vegetation of tree layer in Cymbidium goeringii group was classified into Pinus thunbergii community, Pinus densiflora community, Castanopsis sieboldii community and Quercus variabilis community. Pinus densiflora community showed a strong combination with Cymbidium goeringii group in Korean islets. Pinus thunbergii community among communities was combined with Castanopsis sieboldii community, and Pinus densiflora community and Quercus variabilis community were combined.

• Journal of agriculture & life science
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• v.46 no.3
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• pp.27-36
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• 2012

The purpose of this study was to investigate the structure of the vegetation on the trail of Hallyeo Marine & Coastal National Park. Twenty six $10{\times}10m$ plots were established along the Jisimdo trail. The vascular plants were surveyed from March 2011 to October 2011. Camellia japonica was a major woody species in the study area, while Pinus thunbergii and Zanthoxylum ailanthoides were co-dominant tree species. There were positive correlations between Distylium racemosum and Ligustrum japonicum var. japonicum; Callicarpa japonica var. luxurians and Eurya japonical; Actinodaphne lancifolia and Cinnamomum japonicum; A. lancifolia and Machilus japonica. Positive correlations were found between A. lancifolia and P. thunbergii; Z. ailanthoides and C. japonicum. Species diversity (H') was ranged from 0.51907 to 1.0217, and was relatively low compared to those of same national parks. 10 populations of Milletia japonica which are rare and endemic species, were recorded from the list of rare and endemic species of the Ministry of Environment near by ammo dumps, this study recommend the long term habitat monitoring of the species.

• Korean Journal of Remote Sensing
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• v.21 no.3
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• pp.189-211
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• 2005

This paper makes an effort to compare the recently evolved soft classification method based on Linear Spectral Mixture Modeling (LSMM) with the traditional hard classification methods based on Iterative Self-Organizing Data Analysis (ISODATA) and Maximum Likelihood Classification (MLC) algorithms in order to achieve appropriate results for mapping, monitoring and preserving valuable coastal wetland ecosystems of southern India using Indian Remote Sensing Satellite (IRS) 1C/1D LISS-III and Landsat-5 Thematic Mapper image data. ISODATA and MLC methods were attempted on these satellite image data to produce maps of 5, 10, 15 and 20 wetland classes for each of three contrast coastal wetland sites, Pitchavaram, Vedaranniyam and Rameswaram. The accuracy of the derived classes was assessed with the simplest descriptive statistic technique called overall accuracy and a discrete multivariate technique called KAPPA accuracy. ISODATA classification resulted in maps with poor accuracy compared to MLC classification that produced maps with improved accuracy. However, there was a systematic decrease in overall accuracy and KAPPA accuracy, when more number of classes was derived from IRS-1C/1D and Landsat-5 TM imagery by ISODATA and MLC. There were two principal factors for the decreased classification accuracy, namely spectral overlapping/confusion and inadequate spatial resolution of the sensors. Compared to the former, the limited instantaneous field of view (IFOV) of these sensors caused occurrence of number of mixture pixels (mixels) in the image and its effect on the classification process was a major problem to deriving accurate wetland cover types, in spite of the increasing spatial resolution of new generation Earth Observation Sensors (EOS). In order to improve the classification accuracy, a soft classification method based on Linear Spectral Mixture Modeling (LSMM) was described to calculate the spectral mixture and classify IRS-1C/1D LISS-III and Landsat-5 TM Imagery. This method considered number of reflectance end-members that form the scene spectra, followed by the determination of their nature and finally the decomposition of the spectra into their endmembers. To evaluate the LSMM areal estimates, resulted fractional end-members were compared with normalized difference vegetation index (NDVI), ground truth data, as well as those estimates derived from the traditional hard classifier (MLC). The findings revealed that NDVI values and vegetation fractions were positively correlated ($r^2$= 0.96, 0.95 and 0.92 for Rameswaram, Vedaranniyam and Pitchavaram respectively) and NDVI and soil fraction values were negatively correlated ($r^2$ =0.53, 0.39 and 0.13), indicating the reliability of the sub-pixel classification. Comparing with ground truth data, the precision of LSMM for deriving moisture fraction was 92% and 96% for soil fraction. The LSMM in general would seem well suited to locating small wetland habitats which occurred as sub-pixel inclusions, and to representing continuous gradations between different habitat types.

• Korean Journal of Remote Sensing
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• v.22 no.6
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• pp.575-579
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• 2006

The land use in suburban area has been changed rapidly due to the urban expansion in Korea during the last few decades. And such land use changes result in various environmental problems such as biodiversity decrease, habitat fragmentation, air pollution and urban heat island. Remote Sensing (RS) and Geographical Information Systems (GIS) can be used for land cover change detection to understand the impact and trend of the land use change. Change detection is the process of identifying differences in the state of an object or phenomenon by observing it at different times and it can provide quantitative and comparative information for the land use/cover change. RS is less expansive than field survey for producing land use maps, and can be accessed quickly and repetitively for large area. Also it can be used for change detection using multi-temporal land use/cover by accumulated data. Therefore, the purpose of this study is to detect and quantitatively evaluate urban land cover change in urban stream watershed area for the last few decades and ultimately to provide the basic data for urban land use planning and management.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.1-1
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• 2016

Many of the world's large ecosystems are severely stressed due to population growth, water quality and quantity problems, vulnerability to flood and drought, and the loss of native species and cultural resources. Consequences of climate change further increase uncertainties about the future. These major societal challenges must be addressed through innovations in governance, policy, and ways of implementing management strategies. Science and engineering play a critical role in helping define possible alternative futures that could be achieved and the possible consequences to economic development, quality of life, and sustainability of ecosystem services. Science has advanced rapidly during the past decade with the emergence of science communities coalescing around 'Grand Challenges' and the maturation of how these communities function has resulted in large interdisciplinary research networks. An example is the River Experiment Center of KICT that engages researchers from throughout Korea and the world. This trend has been complemented by major advances in sensor technologies and data synthesis to accelerate knowledge discovery. These factors combine to allow scientific debate to occur in a more open and transparent manner. The availability of information and improved communication of scientific and engineering issues is raising the level of dialogue at the science-policy interface. However, severe challenges persist since scientific discovery does not occur on the same timeframe as management actions, policy decisions or at the pace sometimes expected by elected officials. Common challenges include the need to make decisions in the face of considerable uncertainty, ensuring research results are actionable and preventing science being used by special interests to delay or obsfucate decisions. These challenges are explored in the context of examples from the United States, including the California Bay-Delta system. California transfers water from the wetter northern part of the state to the drier southern part of the state through the Central Valley Project since 1940 and this was supplemented by the State Water Project in 1973. The scale of these activities is remarkable: approximately two thirds of the population of Californians rely on water from the Delta, these waters also irrigate up to 45% of the fruits & vegetables produced in the US, and about 80% of California's commercial fishery species live in or migrate through the Bay-Delta. This Delta region is a global hotspot for biodiversity that provides habitat for over 700 species, but is also a hotspot for the loss of biodiversity with more than 25 species currently listed by the Endangered Species Act. Understanding the decline of the fragile ecosystem of the Bay-Delta system and the potential consequences to economic growth if water transfers are reduced for the environment, the California State Legislature passed landmark legislation in 2009 (CA Water Code SS 85054) that established "Coequal goals of providing a more reliable water supply for California and protecting, restoring, and enhancing the Delta ecosystem". The legislation also stated that "The coequal goals shall be achieved in a manner that protects and enhances the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place." The challenges of integrating policy, management and scientific research will be described through this and other international examples.

• Journal of Korea Water Resources Association
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• v.52 no.spc2
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• pp.865-873
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• 2019

The purpose of this study is to develop and apply a river space restoration framework considering various functions of river basin system. In particular, we will present sustainable river basin management directions by quantifying the effect of improving the aquatic ecosystem through the restoration of river space. For this purpose, the present problems are derived from functional aspects of the river basin, and the river area restoration framework linked with the individual outcome indicators is constructed to evaluate the restoration effect by each function. The ecological impact of restoration of river area was quantitatively analyzed by introducing ecotope concept. As a result of the comparison of restoration effects by creating three kinds of river area restoration scenarios, the construction of suitable habitat such as backswamp in the expanded area has shown favorable results in expanding biodiversity. The diversity evaluation of ecotope in conjunction with the hydraulic and hydrological characteristics of the year will not only provide the expected effects of restoration of river space but will also serve as a criterion about post-project monitoring for outcome evaluation.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.552-564
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• 2019

The purpose of this study was to investigate vegetation characteristics of evergreen broad-leaved forests in the area of Duryunsan Provincial Park, where the deciduous broad-leaved trees and evergreen broad-leaved trees are mixed and thus had a high botanical value. To investigate the vegetation characteristics, we installed 40 quadrats with an area of $100m^2$ each for survey and analysis. Haenam-gun, where the Duryunsan Provincial Park is located, is a warm-temperate forest region. The meteorological data for the past 40 years showed a coldness index of $-8^{\circ}C$, a monthly warmth index of $109.2^{\circ}C$, and annual mean precipitation of 1,310.5mm, indicating it is an ideal habitat for the distribution of evergreen broad-leaved forest. The results of community classification based on TWINSPAN showed three categories of vegetation communities in the surveyed region: Quercus acuta community-I, Q. acuta community-II, and Neolitsea sericea-Aphananthe aspera community. In the evergreen broad-leaved forest in the Duryunsan Provincial Park, Q. acuta dominant in the canopy were expanding their presence in the understory. In addition to the Q. acuta, N. sericea and Cinnamomum yabunikkei, which are evergreen broad-leaved trees of the canopy, were found in all layers. The deciduous broad-leaved trees such as Q. variabilis, Q. serrata, and Carpinus tschonoskii were culled, and the transition to Q. acuta evergreen broad-leaved trees was ongoing. N. sericea community appeared locally. The species diversity index of N. sericea-A. aspera community was lower at 1.0798 than that of Q. acuta Community-I at 1.3208 and Q. acuta Community-II at 1.4916.

• Ecology and Resilient Infrastructure
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• v.6 no.3
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• pp.154-162
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• 2019

Lateral connectivity between the channel and the floodplains has been damaged by the levee construction and channelization in most streams of South Korea. The purpose of this study was to develop a technique for easily and remotely assessing lateral connectivity using GIS in the streams and to evaluate the effectiveness of the assessment method by applying it to Cheongmi-cheon Stream, a representative stream in the central Korean Peninsula. The metrics of the lateral connectivity assessment are composed of (1) existence of remaining wetlands and (2) land use property as a habitat quality of the former floodplain outside the levee and (3) existence of levee barrier, (4) connectivity to the stream and (5) connectivity to the upland natural habitats as a connectivity from the channel through floodplain to the upland forest. According to the result of applying the assessment method to Cheongmi-cheon Stream, the lateral connectivity was severely damaged due to the levee construction and land use change in the former floodplain. The GIS-based assessment of the lateral connectivity developed in this study is expected to be used as a useful tool for identifying limitations of current connectivity in various attempts to restore lateral connectivity in riparian ecosystems.

• Korean Journal of Plant Resources
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• v.13 no.3
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• pp.243-248
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• 2000

This study was conducted to evaluate the effects of weed control and lodging reduction in the cultivation of buckwheat. The effect of weed control was significant. In the herbicide plot, nevertheless, grain yield and plant height were more decreased than habitual and vinyl mulching plots. Therefore, the application of herbicide was considered unnecessary in buckwheat cultivation having short growth period. In the habitual plot, dominant weed species are Digitaria sanguinalis, Erigeron annuus, E. canadensis, Setaria viridis, and Stellaria alsine var. undulata. On the effect of plant dwarf agent, C.C.C. and TIBA, plant height became shorter than habitual plot but the grain yield decreased. The latter tip pinching time, the less in grain yield which indicate tip pinching is ineffective in grain yield and lodging reduction. Among the wild species and cultivars of Fagopyrum, F. urophyllum was differentiated into xylem and phloem tissues indicating woody plant. Stem hardness of this species was the hardest as 625,110,000 dyne/cm$^2$which is at least 3.5 times harder than F. esculentum cv. Suwon #12. Therefore, it needs that the woody habitat gene of F. urophyllum is transfered into other cultivars in buckwheat breeding strategy.