• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.2
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• pp.55-59
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• 2011

Mong Hsu rubies from Myanmar include typically the dark core and blue patch but most of the previous research has merely focused on the dark core. This work is aimed to understanding clearly the characteristic of the dark core and blue patch of Mong Hsu rubies. It was found from the FTIR analysis that the dark core and blue patch region showed the absorption peaks of boehmite ($1986\;cm^{-1}$), diaspore ($2115\;cm^{-1}$) and water ($3400{\sim}3900\;cm^{-1}$) but the absorption peaks of O-H stretching ($3309\;cm^{-1}$ and $3078\;cm^{-1}$) were found only in blue patch region. The UV-VIS-NIR analysis of the dark core region revealed the stronger absorption of $Cr^{3+}$ at 405 and 554 nm compared to the blue patch region. In range of 600~800 nm, the UV absorption characteristic at 659, 675 and 693 nm assigned to $Cr^{3+}$ of core group samples is distinct from that of blue patch. The SEM-EDS examinations disclosed the existence of lots of micro-cracks and pores in the core regions compared to blue patch region.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.8
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• pp.2298-2315
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• 2024

This paper introduces a method aimed at diagnosing the presence or absence of lesions by detecting anomalies in Chest X-ray images. The proposed approach is based on the PatchCore anomaly detection method, which extracts a feature vector containing location information of an image patch from normal image data and calculates the anomaly distance from the normal vector. However, applying PatchCore directly to medical image processing presents challenges due to the possibility of diseases occurring only in specific organs and the presence of image noise unrelated to lesions. In this study, we present an image alignment method that utilizes affine transformation parameter prediction to standardize already captured X-ray images into a specific composition. Additionally, we introduce a region-specific abnormality detection method that requires affine-transformed chest X-ray images. Furthermore, we propose a method to enhance application efficiency and performance through feature map hard masking. The experimental results demonstrate that our proposed approach achieved a maximum AUROC (Area Under the Receiver Operating Characteristic) of 0.774. Compared to a previous study conducted on the same dataset, our method shows a 6.9% higher performance and improved accuracy.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.4
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• pp.53-63
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• 2013

The purpose of this study is to analyze impacts of the forest fragmentation caused by development project. Furthermore, to investigate the applicability of landscape indicator when 'Feasibility of forest land conversion to other use' is conducted. The study site was consisted of golf course development and road construction. It is to compare before and after impacts of areal and linear development. As for the methods, selecting landscape indices, clustered into 3 Categories have been utilized. Category I was concerned with 'size of forest patches', II as 'shape of forest patches', and III as 'Core Area' These were calculated by FRAGSTATS, the program for analyzing fragmentation. The results showed that linear development caused more fragmented than areal development projects. Also, patch size, patch shape and core area are related to impacts of development, while Patch size decreased, patch shape and core area increased after development. Therefore, it is necessary to minimize the impacts of forest by considering fragmentation when development project is planned.

• Journal of Environmental Impact Assessment
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• v.11 no.3
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• pp.117-127
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• 2002

This study tested the usefulness of landscape indices for quantifying forest fragmentation due to linear development projects. Research was carried out in the middle-upper Nakdong River watershed, which has been affected by the expressway building, or national road-widening. Landscape indices were calculated from the forest cover maps before and after road-building using FRAGSTATS 3.1. We could successfully demonstrate the forest fragmentation based on landscape indices; (1) patch size decreased, and edge density and patch density increased (2) roads simplified patch shapes, especially in the larger patches, (3) patch core area size decreased, and core area density increased, (4) the distance increased between the focal patch and each of the other patches within the search radius (=1km) as a result of roads. We suggest several important needs for future researches, including continued investigation of scaling issues, development of indices that measure specific components of spatial pattern, and study of the relationships between forest fragmentation and ecological processes.

• Journal of Korean Society of Rural Planning
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• v.21 no.4
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• pp.27-33
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• 2015

Forest ecosystem is considered as an important stepping stone to minimize the impact of climate change. However, the rapid urbanization has caused fragmentation of forest ecosystem. The fragmentation of forest patch results in edge effect which brings about adverse impacts on forest function and structure. Degradation of forest ecosystem decreases carbon sequestration because edge effect reduces productivity. Therefore, we analyzed the impact of forest edge effect on forest ecosystem carbon stock change in Seongnam-si, Gyeonggi-do. We used connectivity analysis to determine forest edge and core area. The field study sites were selected with considering forest age, density, class and soil type. Secondly, forest carbon stock was calculated with allometric equation. The soil carbon stock was derived from Walkely-Black method. Lastly, Mann-Whitney test was conducted to validate differences between carbon stock in edge and core area. As a result of study, the connectivity analysis was effective to determine forest edge and core. The core and edge of forest patch showed different composition of tree species and soil properties. Carbon stock per tree in the edge area was lower than that in the core area. However, the difference of soil organic carbon content between the edge and core were relatively small. This assessment can be applied for the conservation of forest patch as well as quantitative assessment on the forest carbon stock change caused by fragmentation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.1
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• pp.18-24
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• 2003

A three node triangular element with drilling rotations incorporating improved higher-order zig-zag theory(HZZT) is developed to analyze the vibration of pretwisted composite plates with embedded damping layer. Shear force matching conditions are enforced along the interfaces between the embedded damping patch and the border patch by matching the shear forces of the embedded damping patch to the shear forces of the adjacent border patch. The natural frequencies and modal loss factors are calculated for cantilevered pretwisted composite blade with damping core with the present triangular element, and compared to experiments and MSC/NASTRAN using a layered combination of plate and solid elements.

• Steel and Composite Structures
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• v.32 no.5
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• pp.671-686
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• 2019

Active control of solar panels with honeycomb core and carbon nanotube reinforced composite (CNTRC) facesheets for smart structures using piezoelectric patch sensor and actuator to reduce the amplitude of vibration is a lack of the previous study and it is the novelty of this research. Of active control elements are piezoelectric patches which act as sensors and actuators in many systems. Their low power consumption is worth mentioning. Thus, deriving a simple and efficient model of piezoelectric patch's elastic, electrical, and elastoelectric properties would be of much significance. In the present study, first, to reduce vibrations in composite plates reinforced by carbon nanotubes, motion equations were obtained by the extended rule of mixture. Second, to simulate the equations of the system, up to 36 mode shape vectors were considered so that the stress strain behavior of the panel and extent of displacement are thoroughly evaluated. Then, to have a more acceptable analysis, the effects of external disturbances (Aerodynamic forces) and lumped mass are investigated on the stability of the system. Finally, elastoelectric effects are examined in piezoelectric patches. The results of the present research can be used for micro-vibration suppression in satellites such as solar panels, space telescopes, and interferometers and also to optimize active control panel for various applications.

• Journal of Information Processing Systems
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• v.13 no.5
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• pp.1183-1202
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• 2017

Image restoration has been carried out by texture synthesis mostly for large regions and inpainting algorithms for small cracks in images. In this paper, we propose a new approach that allows for the simultaneous fill-in of different structures and textures by processing in a wavelet domain. A combination of structure inpainting and patch-based texture synthesis is carried out, which is known as patch-based inpainting, for filling and updating the target region. The wavelet transform is used for its very good multiresolution capabilities. The proposed algorithm uses the wavelet domain subbands to resolve the structure and texture components in smooth approximation and high frequency structural details. The subbands are processed separately by the prioritized patch-based inpainting with isophote energy driven texture synthesis at the core. The algorithm automatically estimates the wavelet coefficients of the target regions of various subbands using optimized patches from the surrounding DWT coefficients. The suggested performance improvement drastically improves execution speed over the existing algorithm. The proposed patch optimization strategy improves the quality of the fill. The fill-in is done with higher priority to structures and isophotes arriving at target boundaries. The effectiveness of the algorithm is demonstrated with natural and textured images with varying textural complexions.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.5
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• pp.56-63
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• 2007

This study used the nearest feature model to connect forest patches within the western Geum River Basin. Due to many different forest patch sizes, 3 alternative methods were tested to determine the best way to establish an ecological network with forest patches. Alternative 1 used all forest patches to determine whether patches were large enough. Alternative 2 used forest patches over 10 ha in size. Alternative 3 used natural conservation indices to select forest patches containing better qualities in the natural conservation level. As a result 635 out of 724 patches of over 10 ha were selected for comparison. Alternative 1 showed that forest patches of less than 10 ha were outliers interrupting the establishment of the ecological network. They generated an unnecessary ecological network to link core areas to comparison features. The ecological network was improved by using forest patches greater than 10 ha in size(Alternative 2). Each comparison feature was much more hierarchically connected to core areas in Alternative 2 than in Alternative 1. Forest patches filtered by natural conservation indices were useful for obtaining the best ecological network. Alternative 3 clearly showed the connections in the ecological network between core areas and forest.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.3
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• pp.29-44
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• 2016

The purpose of this study is to quantitatively and visually analyze the degree of green biotope fragmentation caused by road construction and other development work using FRAGSTATS and GUIDOS tool. Moreover, linking of the endangered species research, we mapped "Biotope Fragmentation Map" of Daejeon-city. The findings of the study are summarized as follows: First, as the result of FRAGSTATS, landscape indices : number of patch(NP), mean patch size (MPS), edge length(TE), mean nearest neighbor distance(MNN), edge shape(LSI) showed meaningful change from fragmentation. Moreover, the result of GUIDOS analysis, middle core-small core-bridge-branch-edge-islet-perforation showed increase of area percentage without large core. Lastly, analysis result of 'Biotope Fragmentation Map' revealed that changing site of large core's size appeared eighteen-site and designated as the special protection area appeared forty-one site. As the result of the two data, overlapping areas that showed both change of core size and revealed special protection areas revealed four site. For example, five species of endangered species appeared on the NO. 4 site in 'Biotope Fragmentation Map'. The findings of this study as summarized above are considered to play an important role in basic data preventing green biotope fragmentation at the planned level from various development work.