• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.116-123
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• 1990

Most algorithms utilized the horizontal epipolar lines for solving the correspondence problem in 3-D computer vision. However, the requirement is very difficult to be satisfied in real situations. In this paper, we propose a binocular-stereo matching algorithm, based on line matching method, which does not require the horizontal epipolar lines of the extreme pixels of a given line segment and two circles whose radius is equal to the maximum disparity. And we use the features including the direction of line segments, edge strength and cross-correlation for line matching. The experimental results show that the proposed algorithm can be a useful tool for solving the correspondence problem in 3-D computer vision.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.1
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• pp.657-666
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• 2009

In GIS area, many line simplification algorithms are studied among generalization methods used for making the building data in the form of digital map from the original line data. On the other hand, there are few studies on the simplification algorithm considering the drawing rules of the digital map in Korea. In this paper, the line simplification algorithm based on the drawing rules is proposed as the methodology to create or update the building data of digital map by extracting the building outline from the CAD data used in construction. To confirm the usefulness of the algorithm, this algorithm and four other effective and general line simplification algorithms (e.g., Douglas-Peucker algorithm) are applied to the same building outlines. Then, the five algorithms are compared on five criteria, the satisfaction degree of the drawing rules, shape similarity, the change rate of the number of points, total length of lines, and the area of polygon. As a result, the proposed algorithm shows the 100% of satisfaction degree to the drawing rules. Also, there is little loss in four other mentioned criteria. Thus, the proposed algorithm in this paper is judged to be effective in updating the building data in digital map with construction drawings.

• 한국전산유체공학회:학술대회논문집
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• 2002.10a
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• pp.95-102
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• 2002

Studies of the numerical characteristics of implicit upwind schemes, such as upwind ADI, Line Gauss-Seidel(LGS) and Point Gauss-Seidel(LU) algorithms, for preconditioned Navier-Stokes equations ate performed. All the algorithms are expressed in approximate factorization form and Von Neumann stability analysis and convergence studies are made. Preconditioning is applied for efficient convergence at low Mach numbers and low Reynolds numbers. For high aspect ratio computations, the ADI and LGS algorithms show efficient and uniform convergence up to moderate aspect ratio if we adopt viscous preconditioning based on min- CFL/max- VNN time-step definition. The LU algorithm, on the other hand, shows serious deterioration in convergence rate as the grid aspect ratio increases. Computations for practical applications also verify these results.

• 전자공학회논문지 IE
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• v.45 no.3
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• pp.13-19
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• 2008

In this paper, we propose a new IPC(Interlace to Progressive Conversion) method based on ELA(EDge Line based Average) interpolation using detecting the reliable edge direction. Existing ELA algorithms execute linear interpolation using edge direction without considering noises. In noisy images, these algorithms degrade quality because if interpolation based on the wrong edge direction. Out scheme is able to solve the problem of existing ELA algorithms in noisy images. First, filter a noisy pixel and estimate sizes of the noiseless orginal pixed and the noise, repectively. Then, considering the size of the noise, calculate weights of ELA and vertical interpolation. If noises exist after IPC, these could be eliminated by post filtering. The experimental results show that our proposed algorithm has about $1{\sim}2$ dB better performance than those of existing ELA algorithms.

• Proceedings of the Acoustical Society of Korea Conference
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• 1991.06a
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• pp.38-41
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• 1991

RLS algorithms are required for applications to adaptive line enhancers, adaptive equalizers for voiceband telephone and HF modems, and wide-badn digital spectrum mobile raio in which their convergence time and tracking speed are significant. The fast QR RLS algorithm satisfies above the requirements. Its computational complexity is linearly proportional to the tap number of a filter, N and its performance remains numerically stable. From the result of simumulation, the fast QR RLS algorithm represented Cioffi is better than gradient based algorithm in its initial performance when being applied to an adaptive line enhancer for cancelling noise.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.945-948
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• 2000

The coupling properties of supermodes guided by grating-assisted directional couplers (GADCs) can be phrased in rigorous modal theory. Such a modal solution for TE modes expressed by simple electrical transmission-line networks is utilized to analyze the power distribution of GADCS with three guiding channels. In particular, the modal transmission-line theory can serve as a template for computational algorithms that systematically evaluate the coupling efficiency that are not readily obtained by other methods.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.35-41
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• 2008

Recently needs for the convergence of CAD and GIS data are increasing, and many studies on converting two systems to each other are being carried out. In this study, to revise and update the building data of digital map using CAD data for construction, the outline of building is abstracted from the CAD data and the outline is generalized to the same level of detail with the building data of digital map. Several line simplification algorithms to generalize the outline are adopted and compared, especially at the view of satisfaction to the drawing rule for digital map. Douglas-Peucker algorithm, Lang's algorithm, Reumann-Witkam algorithm, and Opheim algorithm are applied as the line simplification method. To evaluate the results of these algorithms, visual assessment and variation ratio of the number of points, total length of lines, the area of polygon, and satisfaction ratio to the drawing rule of digital map are analyzed. The result of Lang algorithm and Douglas-Peucker algorithm show superior satisfaction ratio. But general satisfaction ratio is 50~60% for all algorithm. Therefore there seems to be a limit to use these algorithms for the simplification method to update the building data in digital map and it is necessary to develop line simplification algorithm which satisfy the drawing rule well.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.7
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• pp.1311-1328
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• 2011

We re-render a photographic image as a simulated pencil drawing using two independent line integral convolution (LIC) algorithms that express tone and feature lines. The LIC for tone is then applied in the same direction across the image, while the LIC for features is applied in pixels close to each feature line in the direction of that line. Features are extracted using the coherent line scheme. Changing the direction and range of the LICs allows a wide range of pencil drawing style to be mimicked. We tested our algorithm on diverse images and obtained encouraging results.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1321-1324
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• 2004

Unbalanced systems, such as distribution systems, have difficulties in fault locations due to single-phase laterals and loads. In this paper, a novel fault location algorithm is suggested for a line to line faults using inverse theorem of matrix on electric power lines. The fault location for balanced systems has been studied using the current distribution factor, by a conventional symmetrical transformation, but that for unbalanced systems has not been investigated due to their high complexity The proposed algorithms overcome the limit of the conventional algorithm using the conventional symmetrical transformation, which requires the balanced system and are applicable to any electric power system but are particularly useful for unbalanced distribution systems. The simulation results oriented by the real distribution system are presented to show its effectiveness and accuracy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2299-2318
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• 2019

Location-aware networks are of great importance for both civil lives and military applications. Methods based on line-of-sight (LOS) measurements suffer sever performance loss in harsh environments such as indoor scenarios, where sensors can receive both LOS and non-line-of-sight (NLOS) measurements. In this paper, we propose a data association (DA) process based on the expectation maximization (EM) algorithm, which enables us to exploit multipath components (MPCs). By setting the mapping relationship between the measurements and scatters as a latent variable, coefficients of the Gaussian mixture model are estimated. Moreover, considering the misalignment of sensor position, we propose a space-alternating generalized expectation maximization (SAGE)-based algorithms to jointly update the target localization and sensor position information. A two dimensional (2-D) circularly symmetric Gaussian distribution is employed to approximate the probability density function of the sensor's position uncertainty via the minimization of the Kullback-Leibler divergence (KLD), which enables us to calculate the expectation step with low computational complexity. Moreover, a distributed implementation is derived based on the average consensus method to improve the scalability of the proposed algorithm. Simulation results demonstrate that the proposed centralized and distributed algorithms can perform close to the Monte Carlo-based method with much lower communication overhead and computational complexity.