• Journal of applied mathematics & informatics
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• 제7권2호
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• pp.493-506
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• 2000

Recently the first author and his coworker report a new finite element method for the Poisson equations with homogeneous Dirichlet boundary conditions on a polygonal domain with one re-entrant angle [7], They use the well-known fact that the solution of such problem has a singular representation, deduced a well-posed new variational problem for a regular part of solution and an extraction formula for the so-called stress intensity factor using tow cut-off functions. They use Fredholm alternative an Garding's inequality to establish the well-posedness of the variational problem and finite element approximation, so there is a maximum bound for mesh h theoretically. although the numerical experiments shows the convergence for every reasonable h with reasonable size y imposing a restriction to the support of the extra cut-off function without using Garding's inequality. We also give error analysis with similar results.

• 대한전자공학회논문지TE
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• 제39권1호
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• pp.37-45
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• 2002

본 논문은 차량계기판에서 벌브를 인식하기 위한 새로운 특징을 제안한다. 대부분의 모델기반 물체 인식에서 사용되는 특징으로는 물체의 다각형 근사점이 있다. 이러한 특징을 이용한 정합방식을 차량계기판의 벌브와 같은 작은 물체에 적용하며, 정합율이 낮다. 이러한 정합율을 높이기 위해서 본 논문에서는 새로운 특징을 제안한다. 제안된 특징은 물체화소의 원분포와 물체의 중심에서 경계선까지의 거리비이다. 본 논문에서는 이러한 세 개의 특징을 모두 같이 이용하기 위해서 새로운 결정함수를 정의한다. 실험 결과는 다각형 근사점을 이용한 정합방식과 3개의 특징을 모두 이용한 정합방식에서의 정합이 되지 않은 물체수로 비교를 한다.

• 한국정밀공학회지
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• 제15권12호
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• pp.7-13
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• 1998

In this paper, an automatic ball-stud inspection system has been developed using the computer-aided vision system. Index table has been used to get the rapid measurement and multi-camera has been used to get the high resolution in physical system. Camera calibration was suggested to perform the reliable inspection. Image processing and data analysis algorithms for ball stud inspection system have been investigated and were performed quickly with high accuracy. As a result, inspection system of a ball stud could be used with a high resolution in real time.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.1120-1123
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• 1995

In this paper, an automatic B/STUD inspection system has been developed using the computer aided vision system. Index Table has been used to get the rapid measurement and multi-camera has been used to get the high resolution in mechanical system. Camera calibration was suggested to perform the reliable Inspection. Image processing and data analysis algorithms for B/STUD inspection system has been investigated and were performed quickly with high accuracy. As a result, Inspection system of a B/STUD can be measured with a high resolution in real time.

• 전자공학회논문지B
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• 제28B권11호
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• pp.866-875
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• 1991

In this paper, multi pulse excited-linear predictive coding (MPE-LPC), where the correlation eliminated residual signal is modeled by a few pules, is shown to be effective for the compression of electrocardiogram (ECG) data, and a more efficient scheme for a faithful reconstruction of ECG is proposed. The reconstruction charateristic of QRS's and P.T waves is improved using the adaptive pulse allocation (APA), and the compression ratio (CR) can be changed by controlling the mumber of modeling pulses. The performance of the proposed method was evaluated using 10 normal and 10 abnormal ECG data. The proposed method had a better performance than the variable threshold amplitude zone time epoch coding (AZTEC) algorithm and the scan-along polygonal approximation (SAPA) algorithm with the same CR. With the CR in kthe range of 8:1 to 14:1, we could compress ECG data efficiently.

• 전자공학회논문지B
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• 제31B권8호
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• pp.119-128
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• 1994

In this paper we propose a new method for the recognition of 2-D partially occluded objects. The border of the object is transformed to a curve in arc length-accumulated interior angle plane. The transformed curve of an image is partitioned so that each segment is bounded by the concave interior angles. In order to tolerate shape distortion due to the polygonal approximation of the boundary of the object a group of feature points of the input image are matched with those of model views. The estimation method for positions and orientations of the identified objects objects is presented.

• Journal of Information Processing Systems
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• 제13권1호
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• pp.174-183
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• 2017

In this paper, we propose a novel feature for recognizing handwritten Odia numerals. By using polygonal approximation, each numeral is segmented into segments of equal pixel counts where the centroid of the character is kept as the origin. Three primitive contour features namely, distance (l), angle (${\theta}$), and arc-tochord ratio (r), are extracted from these segments. These features are used in a neural classifier so that the numerals are recognized. Other existing features are also considered for being recognized in the neural classifier, in order to perform a comparative analysis. We carried out a simulation on a large data set and conducted a comparative analysis with other features with respect to recognition accuracy and time requirements. Furthermore, we also applied the feature to the numeral recognition of two other languages-Bangla and English. In general, we observed that our proposed contour features outperform other schemes.

• 한국정보과학회논문지:시스템및이론
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• 제27권3호
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• pp.245-254
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• 2000

본 논문은 LOD 메쉬 생성을 위한 이산 곡률을 이용한 새로운 오차 척도를 제안한다. 메쉬의 간략화를 위한 이산 곡률은, 부드러운 곡면 추정의 과정 없이 꼭지점 중심의 표면각과 표면적, 이면각 등 의 기하학적 속성만을 이용하여 계산되는 곡률로서, 표면의 특징을 잘 표현하고 있다. 그러므로 이산 곡률에 기반한 새로운 이산 곡률 오차 척도는 원래 모델의 기하학적 형상을 최대로 유지하여 간략화 모델의 정확성을 증가 시키고, 전역 오차 척도로 사용될 수 있다. 또한, 본 논문에서는 LOD 모델을 간략화 비율이 아닌, 오차 척도를 기준으로 생성할 것을 제안한다. 왜냐 하면 LOD는 원래 모델과 각 단계의 간략화된 모델 사이의 근접도에 따라 나누어진 단계를 뜻하기 때문이다. 따라서 이산 곡률 오차 척도는 기존의 오차 척도에 비해 비교적 많은 수학적 연산이 필요하나, 각 단계의 LOD 모델이 원래 모델의 형상을 잘 유지하면서 간략화 비율이 아닌 상세도의 차이를 가지도록 효과적으로 LOD를 생성, 제어할 수 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권1호
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• pp.358-377
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• 2015

In this paper, we propose a novel approach for trajectory recovery. Our system uses a triangulation procedure for skeletonization and graph theory to extract the trajectory. Skeletonization extracts the polyline skeleton according to the polygonal contours of the handwritten characters, and as a result, the junction becomes clear and the characters that are touching each other are separated. The approach for the trajectory recovery is based on graph theory to find the optimal path in the graph that has the best representation of the trajectory. An undirected graph model consisting of one or more strokes is constructed from a polyline skeleton. By using the polyline skeleton, our approach accelerates the process to search for an optimal path. In order to evaluate the performance, we built our own dataset, which includes testing and ground-truth. The dataset consist of thousands of handwritten characters and word images, which are extracted from five handwritten documents. To show the relative advantage of our skeletonization method, we first compare the results against those from Zhang-Suen, a state-of-the-art skeletonization method. For the trajectory recovery, we conduct a comparison using the Root Means Square Error (RMSE) and Dynamic Time Warping (DTW) in order to measure the error between the ground truth and the real output. The comparison reveals that our approach has better performance for both the skeletonization stage and the trajectory recovery stage. Moreover, the processing time comparison proves that our system is faster than the existing systems.

• 정보과학회 논문지
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• 제44권11호
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• pp.1194-1208
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• 2017

잡음제거에 많이 사용되는 평균 스무딩 방법은 곡률이 큰 코너와 잡음을 구분하지 못하므로 코너와 같은 특징점이 이동하거나 없어질 수 있고, 또한 곡선의 수축(shrinking)으로 곡선 내의 면적 오차가 커지는 문제점들이 있다. 이 논문에서는 입력곡선을 다각형 근사화하고 근사화된 다각형의 정보를 스무딩에 이용하여 이 문제점들을 완화시키는 방법을 제안한다. 제안된 방법은 근사화된 다각형과 입력곡선간의 오차와 다각형의 꼭짓점 각도를 이용하여 입력곡선의 각 점마다 개별적으로 스무딩 가중치를 정한다. 이 때 각 점의 가중치는 스무딩 후 점의 이동거리가 그 지역의 잡음크기의 평균에 가까워지도록 정해진다. 제안된 방법으로 잡음이 추가된 곡선을 스무딩하면 스무딩된 곡선이 잡음이 없는 원래곡선에 근접함을 실험으로 확인할 수 있다. 또한 크기가 작은 폐곡선들에 대해 스무딩의 정도를 늘여도 제안된 방법은 기존의 평균 스무딩 방법에 비해 곡선의 면적 축소가 많지 않다.