• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.365-370
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• 2009

The aim of this study was to investigate the vegetation types of Minarimot, in Jeju Islands. The vegetation types were classified by the Z-M school method and cluster analysis. The vegetation in Minarimot was classified into 6 communities and 2 subcommunities: Persicaria thunbergii-Isachne globosa community (vegetation type: A), Scirpus tribangulatus-Eleocharis manillata var. cyclocarpa community (B) (Aneilema keisak subcommunity (B-1) and Caldesia parnassifolia-Potamogeton distinctus subcommunity (B-2)), Eleocharis kuroguwai community (C), Phragmites communis community (D), Scirpus tabernaemontani community(E) and Typha orientalis community (F). These communities were grouped into three main categories according to cluster analysis. The community (A) established at the edge of the wetland which has the driest condition was distinguished as Group I, while the community (B) emerged in the submerged zone was distinguished as Group III. The Group II was designated as the communities (C, D, E, F) between Group I and III, whose communities were occasionally submerged. The result of principal coordinate analysis (PCoA) appeared that the different vegetation established along the wetland were depending on water environment such as water depth and the period submerged.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.1 s.120
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• pp.79-87
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• 2007

The objective of this study was to delineate forest patches in the cities around the Geum-buk mountains at the north of the Geum River using multiplesatellite remote sensing data. Landsat visible and near-infrared satellite images obtained at multiple dates in the growing season were used to create a forest distribution map. Fragstats 3.3 was used to get the landscape indices delineating the distribution of forest patches. Additional ground truth data was used to assess the accuracy of the classification. Factor analysis was used to get the 26 landscape indices clustered into 4 factors. Factor I was labeled as' size of forest patches', factor II as 'fragmentation of forest patches', factor III as 'shape of forest patches', and factor IV as 'complexity of forest patches'. Factor I described large patches and their core area, while others did small patches and their shape and complexity. Cities including Cheonan, Gongju, Cheongyang, and Boryeong near the main ridge of the Geumbuk Mtns. had a small number of large-sized forest patches. However, cities including Taean, Seosan, Dangjin, Hongseong near the ridge of the western Geumbuk Mtns. had a large number of small-sized forest patches. Finally, this study showed that the region near the coast line in Chung-nam province has various types of forest patches having an irregular forest edge due to the elevation and slope lower than the one of the region far from the coast line which is near the ridge of the Geum-buk Mountains. Remote sensing data were useful to understand the distribution of forest patches, and landscape indices could be keys to delineate the relationship between forest patches. And the factor analysis, which simplified 26 landscape indices into 4 landscape patterns allowed us to understand the distribution and relationship of forest patches in an easy way.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.7
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• pp.1371-1378
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• 2017

In this paper, we present an upsampling technique for depth map image using selective bilateral weights and a color weight using laplacian function. These techniques prevent color texture copy problem, which problem appears in existing upsamplers uses bilateral weight. First, we construct a high-resolution image using the bicubic interpolation technique. Next, we detect a color texture region using pixel value differences of depth and color image. If an interpolated pixel belongs to the color texture edge region, we calculate weighting values of spatial and depth in $3{\times}3$ neighboring pixels and compute the cost value to determine the boundary pixel value. Otherwise we use color weight instead of depth weight. Finally, the pixel value having minimum cost is determined as the pixel value of the high-resolution depth image. Simulation results show that the proposed algorithm achieves good performance in terns of PSNR comparison and subjective visual quality.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.9-17
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• 2003

In this paper we proposea method for estimating the bandwidth in next-generation If network. Especially, we concentrate on the edge routers accommodating the VoIP connections as well as a group of data connections. Bandwidth dimensioning is carried out at call level and packet level for voice traffic in the next-generation IP network. The model incorporates the statistical estimation approach at a call level for obtaining the number of voice connections simultaneously in the active mode. The call level model incorporates a statistical technique to compute the statistics of the number of active connections such as the mean and variance of the simultaneously connected calls in the network. The packet level model represents a load map for voice and data traffic by using non-preemptive M/G/1 queuing model with strict priority for voice over data buffer, From the proposed traffic model, we can derive a graph for upper bounds on the traffic load in terms of bandwidth for voice and data connections. Via numerical experiments we illustrate the implication of the work.

• International Journal of Concrete Structures and Materials
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• v.7 no.2
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• pp.95-110
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• 2013

We report various synchrotron radiation laboratory based techniques used to characterize cement based materials in nanometer scale. High resolution X-ray transmission imaging combined with a rotational axis allows for rendering of samples in three dimensions revealing volumetric details. Scanning transmission X-ray microscope combines high spatial resolution imaging with high spectral resolution of the incident beam to reveal X-ray absorption near edge structure variations in the material nanostructure. Microdiffraction scans the surface of a sample to map its high order reflection or crystallographic variations with a micron-sized incident beam. High pressure X-ray diffraction measures compressibility of pure phase materials. Unique results of studies using the above tools are discussed-a study of pores, connectivity, and morphology of a 2,000 year old concrete using nanotomography; detection of localized and varying silicate chain depolymerization in Al-substituted tobermorite, and quantification of monosulfate distribution in tricalcium aluminate hydration using scanning transmission X-ray microscopy; detection and mapping of hydration products in high volume fly ash paste using microdiffraction; and determination of mechanical properties of various AFm phases using high pressure X-ray diffraction.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.4
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• pp.381-390
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• 2010

This paper describes a procedure of the map-based localization for mobile robots by using a sensor fusion technique in structured environments. A combination of various sensors with different characteristics and limited sensibility has advantages in view of complementariness and cooperation to obtain better information on the environment. In this paper, for robust self-localization of a mobile robot with a monocular camera and a laser structured light sensor, environment information acquired from two sensors is combined and fused by a Bayesian sensor fusion technique based on the probabilistic reliability function of each sensor predefined through experiments. For the self-localization using the monocular vision, the robot utilizes image features consisting of vertical edge lines from input camera images, and they are used as natural landmark points in self-localization process. However, in case of using the laser structured light sensor, it utilizes geometrical features composed of corners and planes as natural landmark shapes during this process, which are extracted from range data at a constant height from the navigation floor. Although only each feature group of them is sometimes useful to localize mobile robots, all features from the two sensors are simultaneously used and fused in term of information for reliable localization under various environment conditions. To verify the advantage of using multi-sensor fusion, a series of experiments are performed, and experimental results are discussed in detail.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.5
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• pp.39-60
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• 2018

National parks are designated for the purpose of maintenance, conservation and utilization of different habitats. Therefore, it is necessary to select habitats of a high value as a protected area in order to balance conservation and development. However, the existing national park boundary adjustment and new designation criteria only focused on the endangered species and protected area, without proper evaluation of the habitat value of actual species. Therefore, this study aims to quantitatively evaluate habitat function in terms of biodiversity and habitat value, so that it can be referred to for the designation and boundary adjustment of national parks. We assessed species diversity and habitat values for each of the habitat types, for mammals only, as they are able to choose preferred habitats. In order to evaluate biodiversity, we used Maxent to derive species richness map and used InVEST's Habitat quality model to evaluate habitat value. As a result of evaluation, species richness was high in the national park boundary area. Also, even if the same edge is adjacent to the development area depending on the land cover, the species richness is low. Compared with Wolaksan and Sobaeksan National Park, the species richness and habitat value of the northern area, which is connected with other forests, were higher than those of the southern area where roads were developed. Therefore, it is expected that the use of the result of this study for the national park boundary adjustment and management will enhance the function of the national park as a habitat.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.307-316
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• 2004

This study examined the cause of the wrinkle defect which is frequently encountered in wire rod rolling of low carbon steel$(C0.08\~0.13wt.\%)$. Even a small defect on the surface of rolled bars can easily develop into fatal cracks during cold heading process of low carbon steel, and it is therefore necessary to minimize inherent defects on the surface of hot rolled bars. Hot rolling process of low carbon steel was analyzed to identify the cause of the wrinkle defect in conjunction with FE analysis. The integrated analysis revealed that the wrinkle defect initiated in the first stage of rolling, and it was at the billet edge where severe deformation and drastic temperature drop were present. To elucidate the micro-mechanical mechanism of the wrinkle defect, hot compression tests were carried out at various temperatures and strain rates using Gleeble-3800. The surface profile of the each other compressed specimens was compared, and rough surface lines were observed at relatively low temperatures. Those surface defects can develop into wrinkles during multi-pass rolling. To control the wrinkle defect in rolling, it is necessary to design an adequate caliber which can minimize the loss of ductility, and thereby prevent flow localization. To use the result of this study fur other steels, the quantitative measure of the wrinkle defect and flow localization parameter should be proposed.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.4
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• pp.411-421
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• 2001

The generalized symmetry transform evaluates symmetry without segmentation and extracts regions of interest in an image by combining locality and reflectional symmetry The demand that the symmetry transform be local is reflected by the distance weight function. When calculating large regions-of-interest, we should select a large standard deviation of distance weight function. But such a large standard deviation makes the execution time increase in the second power of r, which is a radius of search area. In this paper we propose modified scan line based GST with selectively directional attention to improve time complexity The symmetry map of our proposed GST is found to be very similar to that of the existing GST. However the computation time of the proposed GST increases linearly with respect to r because our proposed GST evaluates symmetry between a pair of edge pixels along the scan lines. The GST computation decreases considerably when the proposed GST is peformed with selectively directional attention in case of large r. Several experiments in this paper demonstrate the time efficiency and the usefulness of our proposed GST.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.9
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• pp.89-95
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• 2015

In this paper, we propose a real-time two-dimensional bar code detection system even at long range using a vision technique. We first perform short-range detection, and then long-range detection if the short-range detection is not successful. First, edge map generation, image binarization, and connect component labeling (CCL) are performed in order to select a region of interest (ROI). After interpolating the selected ROI using bilinear interpolation, a location symbol pattern is detected as the same as for short-range detection. Finally, the symbol pattern is arranged by applying inverse perspective transformation to localize bar codes. Experimental results demonstrate that the proposed system successfully detects bar codes at two or three times longer distance than existing ones even at indoor environment.