• Korean Journal of Environment and Ecology
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• v.11 no.4
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• pp.486-492
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• 1998

The forests of Osaek-Taech'ongbong-Shinhungsa district in Soraksan National Park was studied to investigate forest structure of tree strata in relation to aspect and altitude of the slope. Excepting the main ridge area which has tyoical environmental condition, tree siwe in canopy of the wouthern slope was smaller, density in canopy of the southern slope was higher and species diversity in tree stratum of the southern slope was lower as compared those of the northern slope of same elevation belts. Elevation trend was found for forest structure of the southern slope where geographical features were similar among elevation belts. With incleasing elevation of the southern slope, basal area of canopy and understory increased. With increasing elevation of the southern slope, importance values of Quercus mongolica, Styrax obassia, and Lindera obtusiloba decreased while those of Pinus koraiensis, Betula ercani, Acer tschonoskii var. rubripes and Rhododendron schlippenbachii increased. According to cluster and ordination analysis, the studied forests was classifide into Quercus mongolica community at the low, middle and high elevation belts of the southern slope and the low and middle elevation belts of the northern slope, Betula ermani community at the elevation belt of the northern slope, and Abies koreana community at the top area.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.6
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• pp.1-8
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• 2009

Detecting entry and exit zones in a view covered by multiple cameras is an essential step to determine the topology of the camera setup, which is critical for achieving and sustaining the accuracy and efficiency of multi-camera surveillance system. In this paper, a graph theoretic clustering method is proposed to detect zones using data points which correspond to entry and exit events of objects in the camera view. The minimum spanning tree (MST) is constructed by associating the data points. Then a set of well-formed clusters is sought by removing inconsistent edges of the MST, based on the concepts of the cluster balance and the cluster density defined in the paper. Experimental results suggest that the proposed method is effective, even for sparsely elongated clusters which could be problematic for expectation-maximization (EM). In addition, comparing to the EM-based approaches, the number of data required to obtain stable outcome is relatively small, hence shorter learning period.

• Journal of the Korean Chemical Society
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• v.60 no.4
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• pp.239-244
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• 2016

We investigated the structures and electronic properties of Cu_mSiO_m+1 clusters with m = 0 - 7. For these clusters, we replaced a Cu atom in the copper oxide clusters with a Si atom. The B3LYP functional and LANL2DZ basis set were used for optimization of the molecular structures of all neutral and charged clusters. The bond distances, bond angles, and Mulliken charges were calculated to study the structural properties. In addition, in order to understand the electronic properties, we examined the ionization energies, electronic affinities, and second differences in energies.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.846-853
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• 1995

In order to study electronic structures for locally disordered systems, we have developed a first-principle self-con-sistent-spin-polarized real space band method (TB-LMTO-R), which combines the tight-binding(TB) linear-muffin-tin orbital(LMTO) band rrethod and the recursion(R) rrethod. The TB-LMTO-R rrethod has been applied to fer-romagnetic bec Fe, hcp Co, and fcc Ni. With varying cluster sizes, recursion coefficients, and the order of the TB-Hamiltonian, we have calculated the local density of states(LDOS) and magnetic moments. It is found that the calculation with 5,000 atoms cluster, 40 continued fractions, and the second-order TB-Hamiltonian yields a conver¬gent result in agreement with those from the conventional LMTO. In this way, we have demonstrated a physical transparency of the TB-LMTO-R method as a real space description.

• The Journal of the Korea Contents Association
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• v.19 no.6
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• pp.359-367
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• 2019

As a strategy for strengthening local competitiveness, efficient use of regional assets is becoming more and more important. The key to regional identity and competitiveness is local assets. The purpose of this study is to derive the priority region for development by evaluating local assets. The analysis methods used in this study are Geographic Information System analysis, Big Data Trend analysis, and Analytic Hierarchy Process analysis. To assess the potential of local assets, the preference of assets, historical value, cluster of resources, wide-area transport accessibility, and population density were set as analysis indicators and itemized weights were applied using AHP to reflect the importance of each item. As a result of analyzing Yeongju city in Gyeongsangbuk-do, eight major points such as Buseoksa Temple, Sosu Seowon, Huibangsa Temple, Punggi Hot Spring Resort, Punggi Station, National Center for Forest Therapy, Yeongju east region and Museom Village were derived.

• Journal of the Korean Vacuum Society
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• v.7 no.s1
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• pp.57-77
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• 1998

Heteroepitaxial $Y_2O_3$ films were grown on a Si(111) substrate by ionized cluster beam deposition(ICBD) in ultra high vacuum, and its qualities such as crystllitnity, film stress, and morphological characteristics were investigated using the various measurement methods. The crystallinity was investigated by x-ray diffraction (XRD) and reflection high energy electron diffraction (RHEED). Interface crystallinity was also examined by Rutherford backscattering spectroscopy(RBS) channeling, transmission electron microscopy(TEM). The stress of the films was measured by RBS channeling and XRD. Surface and interface morphological characteristics were investigated by atomic force microscopy (AFM) and x-ray scattering method. Comparing the interface with the surface characteristics, we can conclude that many defects at the interface region were generated by interface reaction between the yttrium metal and SiO2 layer and by ion beam characteristic such as shallow implantation, so that they influenced the film qualities. The film quality was dominantly depended on the characteristic temperature range. In the temperature range from $500^{\circ}C$ to $600^{\circ}C$, the crystallinity was mainly improved and the surface roughness was drastically decreased. On the other hand, in the temperature range from $600^{\circ}C$ to $700^{\circ}C$, the compressive stress and film density were dominantly increased, and the island size was more decreased. Also the surface morphological shape was transformed from elliptical shape to triangular. The film stress existed dominantly at the interface region due to the defects generation.

• Journal of Veterinary Science
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• v.25 no.1
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• pp.13.1-13.9
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• 2024

Background: Foot-and-mouth disease (FMD) is a highly contagious viral disease in livestock that has tremendous economic impact nationally. After multiple FMD outbreaks, the South Korean government implemented a vaccination policy for efficient disease control. However, during active surveillance by quarantine authorities, pig farms have reported an insufficient antibody positivity rate to FMD. Objective: In this study, the spatial and temporal trends of insufficiency among pig farms were analyzed, and the effect of the number of government veterinary officers was explored as a potential preventive factor. Methods: Various data were acquired, including national-level surveillance data for antibody insufficiency from the Korea Animal Health Integrated System, the number of veterinary officers, and the number of local pig farms. Temporal and geographical descriptive analyses were conducted to overview spatial and temporal trends. Additionally, logistic regression models were employed to investigate the association between the number of officers per pig farm with antibody insufficiency. Spatial cluster analysis was conducted to detect spatial clusters. Results: The results showed that the incidence of insufficiency tended to decrease in recent years (odds ratio [OR], 0.803; 95% confidence interval [95% CIs], 0.721-0.893), and regions with a higher density of governmental veterinary officers (OR, 0.942; 95% CIs, 0.918-0.965) were associated with a lower incidence. Conclusions: This study implies that previously conducted national interventions would be effective, and the quality of government-provided veterinary care could play an important role in addressing the insufficient positivity rate of antibodies.

• Ocean and Polar Research
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• v.27 no.3
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• pp.299-309
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• 2005

The community structure of meiobenthos was studied in the sediment of Kongfjorden, Spitsbergen of Svalbard Island in the Arctic Sea. Samples of meiobenthos were collected in August, 2003. Meiobenthic organisms were collected by SCUBA and van veen grab or acryl sub-corers 34mm in internal diameter, and were taken from upper sediment to a depth of 3cm at each station. A total of 26 meiofaunal groups were found in the sediment of Spitsbergen in Svalbard Island. Nematodes were the most dominant faunal group. Sarcomastigophorans, benthic harpacticoids, and nauplius larvae of crustaceans, were also important components of the meiobenthic community of Kongsfjorden. All of these low faunal groups were comprised of more than 90% of total meiobenthos at every station. The total density of meiobenthos at each station was highest at station MeG 6 $(3,583{\pm}1,137inds./10cm^2)$, and lowest at station $MeG9(28{\pm}1inds./10cm^2)$. Meiobenthos in general showed the highest density in the upper 1cm layer. This may be associated with food and oxygen supply to subsurface. Harpacticoids showed extreme preference at the surface and little presence in layers deeper than 2cm. These animals may be less resistant to oxygen deficiency, and nauplius also showed the same trend. However, in St. MeG 8 and 9, meiobenthos were dense at depths of more than 0-1cm, at especially at depths of 2-3m because of relatively easy penetration of oxygen. Based on the results of cluster analysis, three meiobenthos assemblages were distinguished: one was in the outer and two were in the inner fjord. Station SCU 5 was grouped with the meiobenthos assemblage located in the outer fjord. The outer ford community was characterised by : 1) a relatively low mean number of meiobenthos taxa, 2) a relatively high density of harpacticods and nauplius. One of the inner ford communities (a group of four nation: MeG 2, 3, 8, 9) was in the proximity of the glaciers. Specifically, it was characterised by : 1) a low mean number of meiobenthos taxa, 2) a low density. The other inner ford community was characterised by both a high density and great mean number of meiofaunal taxa.

• Korean Journal of Environment and Ecology
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• v.12 no.4
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• pp.373-380
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• 1999

The Byokryon-Daejangbong valley forest in Keumsan area at Hallyo-Haesang National Park was studied to investigate forest structure in relation to altitude and part of the slope. Forty-eight quadrats were set up in the valley forest along altitude of 200m to 650m and part of the slope. Density, mean DBH, and basal area of the canopy trees were 820~1873trees/ha, 10.7~14.6cm, and 17.7~22.2$\m^2$/ha, respectively. With increasing elevation mean DBH and basal area of tree stratum increased while density of tree stratum decreased. As elevation increased the importance values of Quercus mongolioa, Styrax japonica, Acer pseudo-sieboldiannum, and Sorbus alnifolia increased while those of Pinus thunbergii, Pinus densiflora, Prunus sargentii, Cornus kousa, and Eurya japonica decreased. The importance values of Fraxinus sieboldiana, Quercus variabilis, and Sorbus alnifolia increased as going from lower part to upper part of the slope. However, the opposite trend was found for the importance values of Styrax japonica, Lindera erythrocarpa, and Zelkova serrata, With incresing elevation number of species, species diversity, and evenness incresed and it was suggested that man interference was relatively severe. The range of similarity indices between elevation belts and between parts of the slope were 42.0~71.8% and 74.8~76.8%, respectively. According to importance values and cluster analysis, the studied valley forest was classified into four forest communities of Quercus serrata-Pinus densiflora community in low elevation belt, Carpinus laxiflora-deciduous tree species community in high elevation belt and lower and middle parts at middle elevation belt, Quercus variabilis-Carpinus laxiflora community in upper part at middle elevation belt, and Quercus mongolica-Styrax japonica community in top area. There were significantly positive correlation among Quercus serrata, Pinus densiflora, Pinus thunbergii, and Eurya japonica and among Carpinus laxiflora, Zelkova serrata, and Cornus walteri.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.4
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• pp.124-137
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• 2018

The main purpose of this study is to find the hotspots of crimes that occur frequently in the space and to derive the appropriate CCTV installation location. One of the characteristics of crime is clustered around past occurrence area, and these crimes are strongly correlated. It is also possible to find the cause of the clusters and the variables that affect the crime through the history of the crime. In addition to the traditional OLS model, spatial differential model including spatial autocorrelation and spatial error model were used to select the variables influencing the five major crime rate, the theft rate and the foreign resident rate. The variables affecting the Five major crimes were positive (+) sign for the welfare and the rate of the bar cluster rate, and negative (-) for the street density. The CCTV area occupies 46% of the hotspots based on the overlapping of the areas where the elderly people are crowded, the bar cluster, many multicultural families, and the areas with low density of street lamps. It turned out. Taking into account the current CCTV operation, the total number of new cases to cover the risk point was 89.