• Korean Journal of Plant Taxonomy
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• v.45 no.3
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• pp.213-220
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• 2015

To elucidate the origin and patterns of establishment of insular plants on Ulleungdo Island, maternally inherited chloroplast DNA, which is useful for tracing seed movements, was used. Fagus multinervis, an endemic species that dominated broadleaf deciduous forests on Ulleungdo Island, is an excellent model for such a study. To understand the diversity and spatial distribution of the chloroplast haplotypes of F. multinervis, nucleotide sequences of the psbA-trnH region were determined from 144 individuals sampled throughout the island. Results of a phylogenetic analysis of the region with close relatives of F. multinervis suggest that F. multinervis is sister to a clade of F. japonica and F. engleriana. No haplotype variation was found within F. multinervis. This remarkably low cpDNA haplotype diversity is in contrast to the findings of previous allozyme studies of F. multinervis populations that showed high genetic diversity on Ulleungdo Island. Repeated colonization during the early stage of establishment via birds that migrated from a source area where the F. multinervis cpDNA haplotype was geographically structured may have resulted in the observed pattern of haplotype diversity. Alternatively, long-distance dispersal of seeds of the progenitor of F. multinervis via birds or typhoons to Ulleungdo may have been a single event, whereas the immigration of pollen from the mainland likely occurred frequently. Comparative phylogeographic studies of other species endemic to Ulleungdo Island and their close relatives on the neighboring mainland are necessary for a more complete understanding of the evolution of the island's native species.

• Journal of Wetlands Research
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• v.7 no.2
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• pp.121-132
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• 2005

To classify the surface sedimentary facies using IKONOS image collected over Hwangdo tidal flat in Cheonsu Bay, the optical reflectance was compared for characterizing various sedimentary environments such as grain size, tidal channel pattern and area ratio of surface remnant water. The intertidal DEM (Digital Elevation Model) was generated by echo-sounder for analyzing the relationship between IKONOS image and sedimentary environments including topography. The boundary of the optical reflectance between mud-mixed facies and sand facies was distinct, and discrimination of the associated sandbar feature was also possible. The mud-mixed facies coupled with intricate tidal channels is confined to the relatively hi호 topography of Hwangdo tidal flat. The boundary between mud and mixed flat was indistinct in IKONOS optical reflectance but it would have a difference in the area ratio of surface remnant water. The dark area in the image represented the well developed sand facies having a lot of surface remnant water due to the relatively low surface topography. The overall accuracy of characterizing the surface sediment facies by maximum likelihood classification method was 86.2 %. These results demonstrate that high spatial resolution satellite imagery such as IKONOS coupled with knowledge of grain size, surface remnant water and tidal channel network can be effectively used to characterize the surface sedimentary facies (mud, mixed and sand) network of the tidal flat environments.

• Journal of Cadastre & Land InformatiX
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• v.47 no.1
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• pp.127-142
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• 2017

The purpose of this study is to examine the status of urbanization of Namyangju-Si from 2001 till 2008, analyze the correlation of the change of surrounding land use according to the change of accessibility and analyze the correlation of the change of land use. Based on the result from correlation analysis, I simulated from the view point of interactions between agents of land use and transportation accessibility by using MAS. I tried to forecast, based on space, the change of surrounding land use caused by the change of accessibility. I conducted landscape analysis by using a land registration map. Also, I conducted GIS analysis statistical analysis simulation analysis of traffic data, land use data in order to analyze the correlation of the change of surrounding land use according to the change of accessibility. I could find out a certain pattern that new roads and railroads causes the within 500m adjacent land to change into urban land use, which led me to construct a system through which land use changing phenomenon can be expected according to the change of accessibility. It is expected that it can make the best use of selecting the location where new transportation facilities are constructed.

• Journal of Life Science
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• v.19 no.9
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• pp.1299-1303
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• 2009

The purpose of this study was to analyse the gait characteristics of stroke patients walking on a Zebris system, through quantitative three-dimensional biomechanical analysis. They underwent a continuous rehabilitation training program (RTP). A comparison was made between 3 month and 6 month RTP participants. Their ages were between 60 and 65. The data were analyzed by t-test. The result of comparative analysis of the two groups can be summarized as below. Temporal-spatial data, sagittal plane angular kinematics data, and peak ground reaction force and max pressure data showed that there were no significant differences between the 3 month RTP group and the 6month RTP group (Table 2, Table3, Table 4). It can be suggested that patients with hemiplegia after stroke can improve their walking function through continuous RTP participation.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.506-525
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• 2007

Incision into bedrock channel is the primary control of landform evolution, but research into bedrock incision process stagnated for long time. Due to the scaling problem of the application of results from flume studies to bedrock channel, there is a strong need to simulate the bedrock incision process with more realistic models. As a part of investigation into controls of bedrock channel incision, three-dimensional changes of rock surface with abrasion was investigated with physical modelling. 18 rock plates were abraded with various sediment particle size and sediment load and abraded surfaces of the plates were scanned with high resolution 3-D scanner. To identify the spatial pattern of erosion of the rock plates, various methods were used. There was no synthetic or holistic method that showed all features of bedrock plate produced by abrasion, so each plate was analyzed using some available methods. Contour maps, shaded relief maps and profiles show that abrasion concentrated on the centre of plate (cross profile) and upstream and downstream edges (longitudinal profile) and eroded area extended inwards. It also found that the cracks and boundaries of forming materials easily eroded than other parts. Changing patterns of surface roughness were investigated with profiles, regression analysis and spectral analysis. Majority of plates showed decrease in small-scale roughness, but it depends on microstructures of the plates rather than general hardness or other factors. SEM inspection results supported this idea.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.29-34
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• 2003

Dispersion pattern for adult citrus red mite (CRM), Panonychus citri (McGregor) using by Taylor's power law (TPL) and Iwao's patchiness regression (IPR) was determined to develop a monitoring method on citrus orchards, on Jeju, in Autumn season, during 2001 and 2002.CRM population was sampled by collecting leaves and fruits. The relationships of CRM adults between leaf and fruit were analyzed by different season. The regression equation for CRM adults between leaf (X) and fruit (Y) was ln(Y+1) : 1.029 ln(X+1) ( $r^2$ : 0.80). The density of CRM was higher on fruit than on leaf according to fruit maturing level. TPL provided better description of mean-variance relation-ship for the dispersion indices compared to IPR. Slopes and intercepts of TPL from leaf and fruit samples did not differ between sample units and surveyed years. Fixed-precision levels (D) of a sequential sampling plan were developed using Taylor's power law parameters generated from adults of CRM in leaf sample. Sequential sampling plans for adults of CRM were developed for decision making CRM population level based on the different action threshold levels (2.0,2.5 and 3.0 mites per leaf) with 0.25 precision. The maximum number of trees and required number of trees sampled on fixed sample size plan on 2.0,2.5 and 3.0 thresholds with 0.25 precision level were 19, 16 and 15 and their critical values T$_{critical}$ at were 554,609 and 659, respectively. were 554,609 and 659, respectively.

• Atmosphere
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• v.23 no.4
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• pp.527-538
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• 2013

In this study, climate over Korea based on the Historical scenario induced by HadGEM2-AO is simulated by WRF. For this purpose, a system that can be used be for numerical integration over the Far East Asian area of the center of the Korean Peninsula with 12.5 km-horizontal resolution was set-up at "Haebit", the early portion of KMA Supercomputer Unit-3. Using the system, the downscaling experiments were conducted for the period 1979-2010. The simulated results of HadGEM2-AO and WRF are presented in terms of 2 m-temperature and precipitation during boreal summer and winter of Historical for the period 1981~2005, compared with observation. As for the mean 2 m-temperature, the general patterns of HadGEM2-AO and WRF are similar with observation although WRF showed lower values than observation due to the systematic bias. WRF reproduced a feature of the terrain-following characteristics reasonably well owing to the increased horizontal resolution. Both of the models simulated the observed precipitation pattern for DJF than JJA reasonably, while the rainfall over the Korean Peninsula in JJA is less than observation. HadGEM2-AO in DJF 2 m-temperature and JJA precipitation has warm and dry biases over the Korean Peninsula, respectively. WRF showed cold bias over JJA 2 m-temperature and wet bias over DJF precipitation. The larger bias in WRF was attributed to the addition of HadGEM2-AO's bias to WRF's systematic bias. Spatial correlation analysis revealed that HadGEM2-AO and WRF had above 0.8 correlation coefficients except for JJA precipitation. In the EOF analysis, both models results explained basically same phase changes and variation as observation. Despite the difference in mean and bias fields for both models, the variabilities of the two models were almost similar with observation in many respects, implying that the downscaled results can be effectively used for the study of regional climate around the Korean Peninsula.

• The Plant Pathology Journal
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• v.34 no.5
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• pp.381-392
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• 2018

Clavibacter michiganensis subsp. michiganesis (Cmm) is a quarantine-worthy pest in $M{\acute{e}}xico$. The implementation and validation of new technologies is necessary to reduce the time for bacterial detection in laboratory conditions and Raman spectroscopy is an ambitious technology that has all of the features needed to characterize and identify bacteria. Under controlled conditions a contagion process was induced with Cmm, the disease epidemiology was monitored. Micro-Raman spectroscopy ($532nm\;{\lambda}$ laser) technique was evaluated its performance at assisting on Cmm detection through its characteristic Raman spectrum fingerprint. Our experiment was conducted with tomato plants in a completely randomized block experimental design (13 plants ${\times}$ 4 rows). The Cmm infection was confirmed by 16S rDNA and plants showed symptoms from 48 to 72 h after inoculation, the evolution of the incidence and severity on plant population varied over time and it kept an aggregated spatial pattern. The contagion process reached 79% just 24 days after the epidemic was induced. Micro-Raman spectroscopy proved its speed, efficiency and usefulness as a non-destructive method for the preliminary detection of Cmm. Carotenoid specific bands with wavelengths at 1146 and $1510cm^{-1}$ were the distinguishable markers. Chemometric analyses showed the best performance by the implementation of PCA-LDA supervised classification algorithms applied over Raman spectrum data with 100% of performance in metrics of classifiers (sensitivity, specificity, accuracy, negative and positive predictive value) that allowed us to differentiate Cmm from other endophytic bacteria (Bacillus and Pantoea). The unsupervised KMeans algorithm showed good performance (100, 96, 98, 91 y 100%, respectively).

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.581-587
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• 2013

The amounts of carbon (C), nitrogen (N) and phosphorus (P) in relation to dry weight (D.W.) were measured in zooplankton from the large four rivers (Han R., Geum R., Yeongsan R. and Seomjin R.) during 2004~2008. The stoichiometry of total zooplankton in four river systems was highly variable. The ranges of average C, N and P-contents were $70{\sim}620mgC\;mg^{-1}$ D.W., $7.1{\sim}85.5{\mu}gN\;mg^{-1}$ D.W. and $2.5{\sim}7.4{\mu}gP\;mg^{-1}$ D.W., respectively. The mean C :N: P atomic ratios reflected large spatial differences. The C : P and N : P ratios of the zooplankton community ranged from 38 to 392 : 1 and from 4 to 65 : 1 in all sampling sites. Self-Organizing Map (SOM) was applied to the survey data, and the study sites were clearly classified into 3 clusters. Clustering was largely affected by the distribution pattern of C, N, P-contents, which is related with characteristics of river systems on the basis of stoichiometry.

• Korean Journal of Plant Taxonomy
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• v.43 no.4
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• pp.274-284
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• 2013

This study presents a survey on the bryophytes in Dongbaek-dongsan located at Seonheul Gotjawal on the north-eastern face of Mt. Halla in Jeju Island, Korea. A total of 85 taxa belonging to the Bryophyta (22 families 44 genera 62 species), Marchantiophyta (12 families 16 genera 23 species) were found. Among them, 3 moss species, Diphyscium perminutum Takaki, Racomitrium japonicum Dozy & Molk., and Isopterygium minutirameum (M$\ddot{u}$. Hal.) A. Jaeger. were new additions to the bryophyte flora of Korea. The liverwort index was 27.0%. Predominant life-form was weft. The rates for the bryophytes dominating in mesic to hygric sites were higher than for the bryophytes mainly observed in xeric habitats. We considered that the composition and distribution of species are affected by the different environmental factors according to the evergreen broad-leaved forests, wetlands and exposed spaces. Moreover, the rocks were the substrate type that play a major role in providing the micro-habitats for bryophytes in this area. Particularly, the bryophytes of swamps in this area were very unique and various for its limited space and showed plant communities with mosaic spatial pattern, along with vascular plants. We suggest more detailed and comprehensive studies on the swamps where endemic fern Mankyua chejuense B. -Y. Sun, M. H. Kim & C. H. Kim inhabits to provide valuable information for the conservation and restoration of the species and habitats.