• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.576-576
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• 2016

치수경제성분석, 투자우선순위 및 시설물 규모결정 등의 의사결정과정에서 실무에서는 다차원 홍수피해산정법(MD-FDA)을 현재까지 널리 사용 중이다. 2004년에 개발된 MD-FDA는 대상지역의 자산규모를 행정구역 경계 최소단위인 "읍면동"을 기준으로 계산하여 취합하고, 대상자산이 위치가능한 토지이용정보를 토지피복도로부터 확인하여, 읍면동내 토지이용공간면적을 기준으로 자산정보를 분배(분해)하는 방식으로 이루어진다. 그러나 읍면동 단위의 공간적인 범위는 상당한 면적의 공간적 경계이기 때문에, 이를 평균적인 밀도데이터로 분배 시 공간적인 자산분포에 대해 정밀도를 담보할 수 없다. 이에 본 연구는 행정구역경계인 "읍면동"과 비교할 때 평균적으로 1/30의 면적을 가지는 집계구 단위의 센서스 공간정보자료를 이용하여 방법론을 개선하였고, 이를 MD-FDA 분석체계를 근간으로 센서스자료와 관계된 자료들 간의 연계 및 전체적인 분석과정을 정립하였다. 본 연구에서 제안한 방법을 경기도 동두천시를 대상으로 적용하여 기존 방법에 의한 피해액과 그 차이를 비교하였고, 도로명전자지도의 실제 건물객체 자료(.shp)를 기준으로 오차율을 확인한 결과, 기존 방식에 비해 정밀도가 월등히 향상된 것을 확인할 수 있었다.

• Korean Journal of Remote Sensing
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• v.16 no.3
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• pp.199-209
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• 2000

This study improves the feature tracking method (FTM) in estimating the ocean current vectors from the sequential AVHRR satellite imageries by adding the objective algorithm in defining the edges and boundaries of the oceanic eddies and fronts. It was implemented by using the Sobel operator. The Sobel operator has been proved to be in effective filter in detecting the edges of any object on the image. In estimating the current vectors on the edges defined by the Sobel operator, center coordinates of the Pattern and Search tiles need to be determined by the investigator. The objective feature tracking method combined with maximum cross correlation method (MCC) is turned out to be very efficient and fast, since it uses only parts of the image containing the objects instead of searching the entire image. In the validation with the in situ ADCP measurements of currents in the East Sea, the estimated current speed values are around 35% lower than and current directions are deviated by $34^{\circ}$ from ADCP current vectors. The results are regarded as improved ones compared to the previous investigators'.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.3
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• pp.105-111
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• 2009

In this paper, we propose a locally adaptive image restoration method based on nonlinear extrapolation in frequency domain. In general, the conventional method causes ringing artifacts on the object boundary. To solve this problem, we introduce an improved restoration method which considers textures of an image block. In the proposed method, a blurred image is divided into several blocks, and each block is classified into three groups; simple, one edge, and complex blocks according to the contained texture. Depending on the classification result, adaptive nonlinear extrapolation is applied to each block in a blurred image. Experimental results show that the proposed algorithm can achieve higher quality image in both subjective and objective views as compared with the conventional method.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.1
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• pp.38-46
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• 2004

Image segmentation is the task which partitions the image into meaningful regions and considered to be one of the most important steps in computer vision and image processing. Image segmentation is also widely used in object-based video compression such as MPEG-4 to extract out the object regions from the given frame. Watershed algorithm is frequently used to obtain the more accurate region boundaries. But, it is well known that the watershed algorithm is extremely sensitive to gradient noise and usually results in oversegmentation. To solve such a problem, we propose an image segmentation method which is robust to noise by using stabilized inverse diffusion equation (SIDE) and is more efficient in segmentation by employing multiresolution approach. In this paper, we apply both the region projection method using labels of adjacent regions and the region merging method based on region adjacency graph (RAG). Experimental results on noisy image show that the oversegmenation is reduced and segmentation efficiency is increased.

• Journal of the Korea Society of Computer and Information
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• v.12 no.3
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• pp.131-136
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• 2007

This paper proposes a new approach to eliminate the reflectance component for the detection of text in color images. Color images, printed by color printing technology, normally have an illumination component as well as a reflectance component. It is well known that a reflectance component usually obstructs the task of detecting and recognizing objects like texts in the scene, since it blurs out an overall image. We have developed an approach that efficiently removes reflectance components while preserving illumination components. We decided whether an input image hits Normal or Polarized for determining the light environment, using the histogram which consisted of a red component. We were able to go ahead through the ability to extract by reducing the blur phenomenon of text by light because reflection component by an illumination change and removed it and extracted text. The experimental results have shown a superior performance even when an image has a complex background. Text detection and recognition performance is influenced by changing the illumination condition. Our method is robust to the images with different illumination conditions.

• Journal of Broadcast Engineering
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• v.7 no.3
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• pp.229-237
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• 2002

Natural synthesis of real and virtual images is a key technology in mixed reality. For this purpose, we propose an efficient dense disparity estimation algorithm and a synthesis algorithm considering features of stereo images. Dense disparities are estimated hierarchically from the low to high resolution images. In the process, the region-dividing-bidirectional-matching algorithm makes matching process efficient and keeps the reliability of the estimated disparities, and dense disparities are assigned considering edge information. finally, mixed reality stereo images are synthesized by comparing depth data of real and virtual Images. Computer simulation shows that the proposed algorithms estimate very stable disparity vectors with sharp edge and synthesize natural stereo mixed reality images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6A
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• pp.497-502
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• 2012

In this paper, we present an immersive videoconferencing system that enables gaze correction between users in the internet protocol TV (IPTV) environment. The proposed system synthesizes the gaze corrected images using the depth estimation and the virtual view synthesis algorithms as one of the most important techniques of 3D video system. The conventional processes, however, causes several problems, especially temporal inconsistency of a depth video. This problem leads to flickering artifacts discomforting viewers. Therefore, in order to reduce the temporal inconsistency problem, we exploit the joint bilateral filter which is extended to the temporal domain. In addition, we apply an outlier reduction operation in the temporal domain. From experimental results, we have verified that the proposed system is sufficient to generate the natural gaze-corrected image and realize immersive videoconferencing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11A
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• pp.1880-1888
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• 2001

In wireless communication systems, transmission errors degrade the reconstructed image quality severely. Among various techniques which reduce the degradation, the error concealment technique yields good performance without overheads and the modification of the encoder. In this paper, we have proposed the technique for recovering the corrupted motion vector using the edge direction of blocks which surround the corrupted block, when the video information is compressed by H.263 standard. We uses the property that each object in video sequences shows the same motion. For the estimation of edge directions, the first AC coefficients of blocks are used. Extensive simulation results show that the proposed technique yields good performance with a reduced computational complexity.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.2
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• pp.103-119
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• 2023

Since the Korean government has decided to apply the policy of BIM (Building Information Modeling) to the entire construction industry, it has experienced a positive trend in adoption and utilization. BIM can reduce workloads by building model objects into libraries that conform to standards and enable consistent quality, data integrity, and compatibility. In the domestic architecture, civil engineering, and the overseas landscape architecture sectors, many BIM library standardization studies have been conducted, and guidelines have been established based on them. Currently, basic research and attempts to introduce BIM are being made in Korean landscape architecture field, but the diffusion has been delayed due to difficulties in application. This can be addressed by enhancing the efficiency of BIM work using standardized libraries. Therefore, this study aims to provide a starting point for discussions and present a classification system for objects and attribute information that can be referred to when creating landscape libraries in practice. The standardization of landscape BIM library was explored from two directions: object classification and attribute information items. First, the Korean construction information classification system, product inventory classification system, landscape design and construction standards, and BIM object classification of the NLA (Norwegian Association of Landscape Architects) were referred to classify landscape objects. As a result, the objects were divided into 12 subcategories, including 'trees', 'shrubs', 'ground cover and others', 'outdoor installation', 'outdoor lighting facility', 'stairs and ramp', 'outdoor wall', 'outdoor structure', 'pavement', 'curb', 'irrigation', and 'drainage' under five major categories: 'landscape plant', 'landscape facility', 'landscape structure', 'landscape pavement', and 'irrigation and drainage'. Next, the attribute information for the objects was extracted and structured. To do this, the common attribute information items of the KBIMS (Korean BIM Standard) were included, and the object attribute information items that vary according to the type of objects were included by referring to the PDT (Product Data Template) of the LI (UK Landscape Institute). As a result, the common attributes included information on 'identification', 'distribution', 'classification', and 'manufacture and supply' information, while the object attributes included information on 'naming', 'specifications', 'installation or construction', 'performance', 'sustainability', and 'operations and maintenance'. The significance of this study lies in establishing the foundation for the introduction of landscape BIM through the standardization of library objects, which will enhance the efficiency of modeling tasks and improve the data consistency of BIM models across various disciplines in the construction industry.

• The KIPS Transactions:PartB
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• v.16B no.4
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• pp.299-308
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• 2009

AAM(Active Appearance Model) is an algorithm to extract face feature points with statistical models of shape and texture information based on PCA(Principal Component Analysis). This method is widely used for face recognition, face modeling and expression recognition. However, the detection performance of AAM algorithm is sensitive to initial value and the AAM method has the problem that detection error is increased when an input image is quite different from training data. Especially, the algorithm shows high accuracy in case of closed lips but the detection error is increased in case of opened lips and deformed lips according to the facial expression of user. To solve these problems, we propose the improved AAM algorithm using lip feature points which is extracted based on a new lip detection algorithm. In this paper, we select a searching region based on the face feature points which are detected by AAM algorithm. And lip corner points are extracted by using Canny edge detection and histogram projection method in the selected searching region. Then, lip region is accurately detected by combining color and edge information of lip in the searching region which is adjusted based on the position of the detected lip corners. Based on that, the accuracy and processing speed of lip detection are improved. Experimental results showed that the RMS(Root Mean Square) error of the proposed method was reduced as much as 4.21 pixels compared to that only using AAM algorithm.