• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.927-928
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• 2008

In this paper, a interpolation error concealment algorithm of motion compensated interpolated frame for motion compensated frame rate conversion to reduce the block artifacts caused by failure of conventional motion estimation based on block matching algorithm is proposed. Experimental results show good performance of the proposed scheme with significant reduction of the block artifacts.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.213-214
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• 2006

To reduce the feedback overhead of predicted CSI (channel status information) of adaptive OFDM (orthogonal frequency division multiplexing), we use partial data of CSI and employ linear interpolation. Simulation results show estimated CSI and its MSE.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.363-364
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• 2007

In this paper, we present a novel motion-compensated interpolation technique for non-moving caption region to prevent the block artifacts due to the failure of conventional block-based motion estimation algorithm on the block is consist of non-moving caption and moving object. Experimental results indicate good performance of the proposed scheme with significantly reduced block artifacts on image sequence that include non-moving caption. Also the proposed method is simple and adequate for hardware implementation.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1610-1613
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• 2016

An analytical method for harmonic estimation of magnetization currents has been developed. The method is based on the results of the waveforms qualitative analysis. The calculation and the experimental results are compared. A good matching is observed.

• Communications for Statistical Applications and Methods
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• v.8 no.1
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• pp.15-27
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• 2001

One proposal is made for constructing nonparametric estimator of slope parameters in a regression model under symmetric error distributions. This estimator is based on the use of idea of Johns for estimating the center of the symmetric distribution together with the idea of regression quantiles and regression trimmed mean. This nonparametric estimator and some other L-estimators are studied by Monte Carlo.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.15-23
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• 2016

To support the telematics and infotainment services, vehicle-to-everything (V2X) communication requires a robust and reliable network. To do this, the 3rd Generation Partnership Project (3GPP) has recently developed V2X communication. For reliable communication, accurate channel estimation should be done. However, because vehicle speed is very fast, radio channel is rapidly changed with time. Therefore, it is difficult to accurately estimate the channel. In this paper, we propose the new linear minimum mean square error (LMMSE) channel interpolation scheme based on the Long Term Evolution (LTE) sidelink system in vehicle-to-vehicle (V2V) environments. In our proposed reduced decision error (RDE) channel estimation scheme, LMMSE channel estimation is applied in the pilot symbol, and then in the data symbol, smoothing and LMMSE channel interpolation scheme is applied. After that, time and frequency domain averaging are applied to obtain the whole channel frequency response. In addition, the LMMSE equalizer of the receiver side can reduce the error propagation due to the decision error. Therefore, it is possible to detect the reliable data. Analysis and simulation results demonstrate that the proposed scheme outperforms currently conventional schemes in normalized mean square error (NMSE) and bit error rate (BER).

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.11 no.3
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• pp.178-183
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• 2011

The deterministic annealing-based clustering algorithm is an EM-based algorithm which behaves like simulated annealing method, yet less sensitive to the initialization of parameters. Pairwise clustering is a kind of clustering technique to perform clustering with inter-entity distance information but not enforcing to have detailed attribute information. The pairwise deterministic annealing-based clustering algorithm repeatedly alternates the steps of estimation of mean-fields and the update of membership degrees of data objects to clusters until termination condition holds. Lacking of attribute value information, pairwise clustering algorithms do not explicitly determine the centroids or medoids of clusters in the course of clustering process or at the end of the process. This paper proposes a method to identify the medoids as the centers of formed clusters for the pairwise deterministic annealing-based clustering algorithm. Experimental results show that the proposed method locate meaningful medoids.

• Journal of the Optical Society of Korea
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• v.19 no.4
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• pp.390-396
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• 2015

We propose a partial occlusion removal method for computational integral imaging reconstruction (CIIR) based on the usage of the exemplar based inpainting technique. The proposed method is an improved version of the original linear inpainting based CIIR (LI-CIIR), which uses the inpainting technique to fill in the data missing region. The LI-CIIR shows good results for images which contain objects with smooth surfaces. However, if the object has a textured surface, the result of the LI-CIIR deteriorates, since the linear inpainting cannot recover the textured data in the data missing region well. In this work, we utilize the exemplar based inpainting to fill in the textured data in the data missing region. We call the proposed method the neighboring elemental image exemplar based inpainting (NEI-exemplar inpainting) method, since it uses sources from neighboring elemental images to fill in the data missing region. Furthermore, we also propose an automatic occluding region extraction method based on the use of the mutual constraint using depth estimation (MC-DE) and the level set based bimodal segmentation. Experimental results show the validity of the proposed system.

• Journal of the Korea Computer Graphics Society
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• v.30 no.3
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• pp.141-147
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• 2024

Progressive photon mapping is a widely adopted rendering technique that conducts a kernel-density estimation on photons progressively generated from lights. Its hyperparameter, which controls the reduction rate of the density estimation, highly affects the quality of its rendering image due to the bias-variance tradeoff of pixel estimates in photon-mapped results. We can minimize the errors of rendered pixel estimates in progressive photon mapping by estimating the optimal parameters based on gradient-based optimization techniques. To this end, we derived the gradients of pixel estimates with respect to the parameters when performing progressive photon mapping and compared our estimated gradients with finite differences to verify estimated gradients. The gradient estimated in this paper can be applied in an online learning algorithm that simultaneously performs progressive photon mapping and parameter optimization in future work.

• The Journal of the Acoustical Society of Korea
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• v.43 no.5
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• pp.529-535
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• 2024

This paper presents our research on automatic audio panning for media content production. Previously, tracking an audio was done manually. With the advent of the immersive audio era, the need for an automatic audio panning system has increased, yet no substantial research has been progressed to date. Therefore, we propose a computer vision-based human tracking and depth feature processing system which processes depth feature through using 2-dimensional coordinates and models 3-dimensional view transformation for automatic audio panning to ensure audiovisual congruence. Also, this system applies stage size estimation model which gets input as an image and extrapolates stage width and depth as meter unit. Since our system estimates stage sizes and directly applies them to view transformation, no additional depth data training is required. To validate the proposed system, we also conducted a pilot test with Unity based sample video. Our team expects that our system will enable automated audio panning, assisting many audio engineers.