• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.772-775
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• 2006

Muilti-dimensional feature vector matching algorithm uses multiple features such as intensity, gradient, variance, first or second derivative of a pixel to find correspondence pixels in stereo images. In this paper, we proposed a new method for adjusting automatically the weight of feature in multi-dimensional feature vector matching considering sharpeness of a pixel in feature vector distance curve. The sharpeness consists of minimum and maximum vector distances of a small window mask. In the experiment we used IKONOS satellite stereo imagery and obtained accurate matching results comparable to the manual weight-adjusting method.

• 한국전기전자재료학회논문지
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• 제25권4호
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• pp.321-327
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• 2012

To evaluate whether or not their product is in conformity with its drawing, today's factories manufacturing rubber and/or plastic products use manual process. In manual conformity inspection process, a person decides conformity as comparing drawing to image of product with his eyes. The manual process is tedious and time-consuming in addition that it is impossible to automatically record various informations related to inspection. To solve such problems, this paper proposes automatic drawing conformity inspection system based on computer vision technologies such as image feature matching and bilinear interpolation. The test results show that proposed system is a lot faster when comparing with manual system.

• 한국안전학회지
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• 제37권1호
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• pp.41-48
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• 2022

Bridge engineering documents have essential contents that must be referenced continuously throughout a structure's entire life cycle, but research related to the quality of the contents is still lacking. XML schema matching is an excellent technique to improve the quality of stored data; however, it takes excessive computing time when applied to documents with many contents and a deep hierarchical structure, such as bridge engineering documents. Moreover, it requires a manual parametric study for matching elements' weight factors, maintaining a high matching accuracy. This study proposes an efficient weight-factor determination method based on an artificial neural network (ANN) model using the simplified XML schema-matching method proposed in a previous research to reduce the computing time. The ANN model was generated and verified using 580 data of document properties, weight factors, and matching accuracy. The proposed ANN-based schema-matching method showed superiority in terms of accuracy and efficiency compared with the previous study on XML schema matching for bridge engineering documents.

• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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• pp.2393-2398
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• 2012

Objectives: The purpose of this study was to evaluate the geometric accuracy of thoracic anatomic landmarks as target surrogates of intrapulmonary tumors for manual rigid registration during image-guided radiotherapy (IGRT). Methods: Kilovolt cone-beam computed tomography (CBCT) images acquired during IGRT for 29 lung cancer patients with 33 tumors, including 16 central and 17 peripheral lesions, were analyzed. We selected the "vertebrae", "carina", and "large bronchi" as the candidate surrogates for central targets, and the "vertebrae", "carina", and "ribs" as the candidate surrogates for peripheral lesions. Three to six pairs of small identifiable markers were noted in the tumors for the planning CT and Day 1 CBCT. The accuracy of the candidate surrogates was evaluated by comparing the distances of the corresponding markers after manual rigid matching based on the "tumor" and a particular surrogate. Differences between the surrogates were assessed using 1-way analysis of variance and post hoc least-significant-difference tests. Results: For central targets, the residual errors increased in the following ascending order: "tumor", "bronchi", "carina", and "vertebrae"; there was a significant difference between "tumor" and "vertebrae" (p = 0.010). For peripheral diseases, the residual errors increased in the following ascending order: "tumor", "rib", "vertebrae", and "carina"; There was a significant difference between "tumor" and "carina" (p = 0.005). Conclusions: The "bronchi" and "carina" are the optimal surrogates for central lung targets, while "rib" and "vertebrae" are the optimal surrogates for peripheral lung targets for manual matching of online and planned tumors.

• 한국측량학회지
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• 제14권1호
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• pp.9-16
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• 1996

본 연구에서는 상호표정과 사진기준점측량을 위한 새로운 매칭방법을 제안하였다. 이 방법은 수작업에 의한 점이사와 관측을 대신하여 디지탈 항공사진에서 연결점과 접합점으로 사용할 수 있는 공액점들을 매칭한다. 제안된 매칭방법에는 다음과 같은 세 가지의 독특한 단계가 포함되어 있다. 첫째 단계는 interest point를 찾고 이들을 매칭후보점으로 사용한다. 둘째 단계는 중복찰영된 서상에서 표준상관계수법에 의해 양방향으로(왼쪽에서 오른쪽으로 오른쪽에서 왼쪽으로) 매칭을 실시한다. 세째 단계는 양매칭방향에서 일치성이 있는 쌍들을 선택한다. 제안된 매칭방법에 기초한 컴퓨터 프로그램을 개발하고, 전면지상기준점측량을 실시한 디지탈 항공사진을 이용하여 제안된 방법을 사용하였을 때의 신뢰성과 위치정확도를 조사하기 위한 시험을 하였다. 시험 결과 제안된 매칭방법은 다른 매칭방법보다 불량하게 매칭된 쌍들을 제거하는 데 더 효과적이었으며 , 따라서 이 방법을 상호표정 및 사진기준점측량에 사용할 경우 매우 매우 신뢰성이 높다.

• 한국콘텐츠학회논문지
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• 제6권6호
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• pp.1-8
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• 2006

본 연구에서는 인쇄회로기판을 위한 자동 광학 검사시스템에서 핵심적인 기능인 보정 데이타 산출을 위한 기하학적 특징 기반 방법을 제안하였다. 현재 적용되고 있는 자동 광학 검사 시스템에서는 보정데이타 산출을 위해 작업자가 직접 수작업으로 모델을 설정하고 있고, 검사영상에 기하학적인 변화가 있는 경우 비검사영역이 생기는 등 문제가 발생되고 있다. 이는 검사 작업의 신뢰성에 영향을 미치게 됨은 물론 검사 처리 시간을 지연시키는 요인이 된다. 제안된 방법은 주어진 PCB 영상으로부터 기하학적인 모양이 적합한 모델을 자동으로 선정할 수 있고, 기하학적인 모델 매칭 기법을 통해 신뢰성 있는 보정데이타를 산출할 수 있다. 제안된 방법의 사용으로 검사 시스템을 보다 편리하게 사용할 수 있고, 수작업에 의한 모델설정으로 발생되는 불필요한 시간을 절약할 수 있다. 또한, 기하학적인 변화량에 관계없이 보정데이타 산출이 가능하고, 잘못된 모델 선정 등 부정확한 보정데이터의 사용시 발생되는 문제점을 해결할 수 있는 장점을 갖는다.

• 전자공학회논문지A
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• 제33A권5호
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• pp.203-211
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• 1996

This paper describes CAD tools for the construction of image database in IC chip analysis CAD system. For IC chip analysis by high-resolution microscopy, the image database is essential to manage more than several thousand images. But manual database construction is error-prone and time-consuming. In order to solve this problem, we develop a set of CAD toos that include image grabber to capture chip images, image editor to make the whole chip image database from the grabbed images, and image divider to reconstruct the database that consists of evenly overlapped images for efficient region search. we also develop an interactive pattern matching method for user-friendly image editing, and a heuristic region search method for fast image division. The tools are developed with a high-performance graphic hardware with JPEG image comparession chip to process the huge color image data. The tools are under the field test and experimental resutls show that the database construction time can be redcued in 1/3 compared to manual database construction.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.518-523
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• 2002

Nowadays the Rational Function Model (RFM), an abstract sensor model, is substituting physical sensor models for highly complicated imaging geometry. But RFM is algorithm to be required many Ground Control Points (GCP). In case of RFM of the third order, At least forty GCP are required far RFM generation. The purpose of this study is to research more efficient algorithm on GCP and accurate algorithm similar to RFM. The Polynomial Camera Model is relatively accurate and requires a little GCP in comparisons of RFM. This paper introduces how to generate Polynomial Camera Model and fundamental algorithms for construction of 3-D topographic data using the Polynomial Camera Model information in the Kompsat stereo pair and describes how to generate the 3-D ground coordinates by manual matching. Finally we tried to extract height information for the whole image area with the stereo matching technique based on the correlation.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.542-542
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• 2002

Geometric correction is a critical step to remove geometric distortions in satellite images. For correct geometric correction, Ground Control Points (GCPs) have to be chosen carefully to guarantee the quality of corrected satellite images. In this paper, we present an automatic approach for geometric correction by constructing GCP Chip database (GCP DB) that is a collection of pieces of images with geometric information. The GCP DB is constructed by exploiting Landsat's nadir-viewing property and the constructed GCP DB is combined with a simple block matching algorithm for efficient GCP matching. This approach reduces time and energy for tedious manual geometric correction and promotes usage of Landsat images.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.223-226
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• 1998

The control objective of steam generator water level in the secondary circuit of a nuclear power plant is to regulate the water level at the desired set point. The dynamics of steam generators is non-linear in nature. The task of modelling such plant is very difficult and especially so when plant operating conditions change frequently. In these reasons, conventional PI gains over all pover range will not work efficiently and a manual control is generally used in low power operation. Therefore the robust H$\infty$ controller design method should be required. In this paper, we design the robust H$\infty$ controller for water level control of steam generator using a mixed H$\infty$ optimization with model-matching method. Firstly we choose the desired model that has good disturbance rejection performance. Secondly we design a stabilizing controller to keep the model-matching error small and also provide sufficiently large stability margin against additive perturbations of the nominal plant.