• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.5
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• pp.432-441
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• 2007

Image processing methods for an extraction of a nuclear fuel rod image and visualization methods of the RGB color data were studied with a sectional image of spent fuel assembly. The fuel rod images could be extracted by using a histogram analysis, an edge detection and RGB rotor data. In these results, a size of the spent fuel assembly could be measured by using a histogram analysis method and a shape of the spent fuel rod could be observed by using an edge detection method. Finally, a various analyses were established for status of the spent fuel assembly by realized various 3D images for the color data in an image of a spent fuel assembly.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.10
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• pp.777-788
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• 2006

This paper describes a displacement mapping technique which represents protruded shapes on the surface of an object. Previous approaches for image-based displacement mapping can represent only shapes depressed from the polygon surface. The proposed technique can represent shapes protruded from the underlying surface in real-time. Two auxiliary surfaces which are perpendicular to the underlying surface are added along the boundary of the polygon surface, in order to represent the pixels which overflow over the boundary of the polygon surface. The proposed approach can represent accurate silhouette of protruded shape. It can represent not only smooth displacement of protruded shape, but also abrupt displacement such as perpendicular protrusion by means of adding the supplementary texture information to the steep surface of protruded shape. By per-pixel instructions on the programmable GPU this approach can be executed in real-time. It provides an effective solution for the representation of protruded shape such as high-rise buildings on the ground.

• Journal of Korea Multimedia Society
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• v.17 no.3
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• pp.342-352
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• 2014

This paper proposes an automatic segmentation method of cortical bone and trabecular bone and describes an implementation of structural analysis method of trabecular bone in micro-CT images. The proposed segmentation method extract bone region with binarization using a threshold value. Next, it finds adjacent contour lines from outer boundary line into inward direction and sets candidate regions of cortical bone. Next it remove cortical bone region by finding the candidate cortical region of which the average pixel value is maximum. We implemented the method which computes four structural indicators BV/TV, Tb.Th, Tb.Sp, Tb.N by using VTK(Visualization ToolKit) and sphere fitting algorithm. We applied the implemented method to twenty proximal femur of mouses and compared with the manual segmentation method. Experimental result shows that the average error rates between the proposed segmentation method and the manual segmentation method are less than 3% for the four structural indicatiors. This result means that the proposed method can be used instead of the combersome and time consuming manual segmentation method.

• Tunnel and Underground Space
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• v.14 no.5
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• pp.345-352
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• 2004

In a shotcrete support system, the cooperation of the ground and the shotcrete lining makes it possible to transfer the shear stress to the shotcrete lining, which is dedicated to form a stable structure. In this study, a homogeneous model ground with constant strength was produced by using gypsum and the tunnel was excavated with a top heading method under the definite initial stress. During the excavation, the stress in the ground around the tunnel and the deformation of shotcrete lining were measured, The tensile stress was generated in tangential direction in the ground near the tunnel and in the shotcrete lining due to tunnel excavation. This shows the unified behavior of the ground and shotcrete lining, which is the most typical characteristic of the shotcrete support. As a result, the rates of in-situ stress during the excavation at a top boundary line was 9% and at top arch heading 15%. It was 48% right after excavating the heading and 94% before cutting the bench.

• Spatial Information Research
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• v.3 no.2
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• pp.91-102
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• 1995

The purposes of this paper are to find ways to detect ecotone between two eco'||'&'||'not;systems, measure the width and size of ecotone around the Mt. Pukhansan National Park, and investigate environmental impacts, if any, on the forest ecosystem of the park by human activities. Normalized Difference Vegetation Index(NDVI) derived from TM data and the ana'||'&'||'not;lytical capabilities of GIS are used to investigate characteristics of the ecotone, or the impact zone, of the park. Major findings of the study can be summarized as follows: First, it was found that ecotone of the park could be identified from NDVI -distance curves deri"ed by a series of buffering op'||'&'||'not;erations. Second, NDVIs of all three years of the national park are about 14 percent higher than surrounding areas. Third, width of ecotone were found to be closely related to phenology, adjacent land use, environmental degradation, etc. Third, ecotone of the study area was nearly douvled during 1985-1993 period, which might be caused by heavy trampling of visitors. Thus it can be concluded that further studies are needed to find exact causes of the deterioration of plant communities of the ecotone of the park.

• Journal of Broadcast Engineering
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• v.20 no.3
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• pp.398-407
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• 2015

Compressive sensing (CS) has drawn much interest as a novel sampling technique that enables sparse signal to be sampled under the Nyquitst/Shannon rate. By noting that the block-based CS can still keep spatial correlation in measurement domain, this paper proposes to adapt sampling rate of each block in frame according to its characteristic defined by edge information. Specifically, those blocks containing more edges are assigned more measurements utilizing block-wise correlation in measurement domain without knowledge about full sampling frame. For natural image, the proposed adaptive rate allocation shows considerable improvement compared with fixed subrate block-based CS in both terms of objective (up to 3.29 dB gain) and subjective qualities.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.6
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• pp.101-108
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• 1998

An efficient approach to recognize occluded objects is to detect a number of essential features on the boundary of the unknown shape. The salient points including corner points, tangential points and inflection points are detected by the relation of neighboring pixels of each pixel on the boundaries. Corner points are usually detected in the curvature function and tangential points and inflection points are detected by median filtering the curvature function to avoid the effect of quantization noise as corner points is not sufficient to represent an object with lines and arcs. Then, these salient points are used as features for object matching. Discrete Hopfield Neural Network is used for object matching. Experimental results show that the matching result using salient points is better than those of using corner points only when an object consists of lines and arcs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1686-1694
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• 2014

In this paper, a new scheme to recognize a finger shape in the depth image captured by Kinect is proposed. Rigid transformation of an input finger shape is pre-processed for its robustness against the shape angle of input fingers. After extracting contour map from hand region, observing the change of contour pixel location is performed to calculate rotational compensation angle. For the finger shape recognition, we first acquire three pixel points, the most left, right, and top located pixel points. In the proposed algorithm, we first acquire three pixel points, the most left, right, and top located pixel points for the finger shape recognition, also we use geometrical features of human fingers such as Euclidean distance, the angle of the finger and the pixel area of hand region between each pixel points to recognize the finger shape. Through experimental results, we show that the proposed algorithm performs better than old schemes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.422-428
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• 2011

In this paper, we introduce system and channel modeling for an underwater ad hoc acoustic network with n regularly located nodes， and then analyze capacity scaling laws based on the model. A narrow-band model is assumed where the carrier frequency is allowed to scale as a function of n. In the network, we characterize in attenuation parameter that depends on the frequency scaling as well as the transmission distance. A cut-set upper bound on the throughput scaling is then derived in extended networks having unit node density. Our result indicates that the upper bound is inversely proportional to the attenuation parameter, thus resulting in a power-limited network. Furthermore, we describe an achievable scheme based on the simple nearest-neighbor multi-hop (MH) transmission. It is shown under extended networks that the MH scheme is order-optimal for all the operating regimes expressed as functions of the attenuation parameter.

• Journal of Navigation and Port Research
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• v.26 no.5
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• pp.517-524
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• 2002

This study aims to analyse the actual conditions of Korean fishing boat being seized in Japan's EEZ and to provide the countermeasures against that problem. According to the analysis of that actual conditions, Korean fishermen are trespassing Japan's EEZ in which fishery resources are abundant because of exhaustion of fishery resources and polluted water in Korean coastal sean. In the past, That behavior was not illegal. Now, however, it became illegal with the effectuation of the United National Conventions on the Law of the Sea(1994) and the Korean-Japanese Fisheries Agreement(1999). In order to resolve that problem on a long-term basis, it is necessary to turn over national fishery policy, to provide fishing people with other means of living, and to establish the Korean-Japanese cooperation system of fishery management. Most of all, it is urgent to mitigate and remit a penalty which was executed in Japan, to amplify personal and material resources need to guide and control fishery, and to construct a close cooperation system between the National Maritime Policy Agency and the Ministry of Maritime and Fisheries Affairs.