• MALSORI
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• no.52
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• pp.133-144
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• 2004

The quality of narrowband speech can be enhanced by the bandwidth extension technology. This paper proposes a mixed excitation and an energy compensation method based on Gaussian Mixture Model (GMM). First, we employ the mixed excitation model having both periodic and aperiodic characteristics in frequency domain. We use a filter bank to extract the periodicity features from the filtered signals and model them based on GMM to estimate the mixed excitation. Second, we separate the acoustic space into the voiced and unvoiced parts of speech to compensate for the energy difference between narrowband speech and reconstructed highband, or lowband speech, more accurately. Objective and subjective evaluations show that the quality of wideband speech reconstructed by the proposed method is superior to that by the conventional bandwidth extension method.

• Journal of Korea Multimedia Society
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• v.15 no.12
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• pp.1442-1448
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• 2012

The problem of Metal Area Segmentation (MAS) in X-ray CT images is a very hard task because of metal artifacts. This research features a practical yet effective method for MAS in X-ray CT images that exploits both projection image and reconstructed image spaces. We employ the Relevant Neighbor Area (RNA) idea [1] originally developed for projection image inpainting in order to create a novel feature in the projection image space that distinctively represents metal and near-metal pixels with opposite signs. In the reconstructed result of the feature image, application of a simple thresholding technique provides accurate segmentation of metal areas due to nice separation of near-metal areas from metal areas in its histogram.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.155-161
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• 2009

Any classification process using SAR images presupposes the reduction of multiplicative speckle noise, since the variations caused by speckle make it extremely difficult to distinguish between neighboring classes within the feature space. This paper focus an argument of effective filter for preserving the weak boundaries by using the proposed method. To reduce speckle noise without blurring the edges of reconstructed image use wavelet-based sigma filter. As a result, the edge information of reconstructed image reduce blurring. Simulation results show that proposed method gives a better subjective quality than conventional methods for the speckle noise.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.86-91
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• 2008

Purpose: The performance of rhinoplasty on the patient who has already undergone unsatisfactory results or complications after augmentation rhinoplasty is a challenging surgical problem. Because the dead space is remained after removal of the foreign body and the thickness of the skin is not even, the deformity would be more conspicuous if the nose is reconstructed again with hard implant only or autogenous cartilage. In these cases, the autogenous fascia can be used to get a good result. We present our clinical experience of secondary rhinoplasty using Scarpa's fascia of lower abdomen. Methods: Thirty-two patients underwent the procedure from March of 2002 to February of 2007. Nine patients were reconstructed with Scarpa's fascia only, eighteen patients were reconstructed with silicone implant and fascia, and five patients were reconstructed with cartilage and fascia for secondary rhinoplasty. Results: There were no major complications. Most of the patients were satisfied with the results. The deviation of the silicone implant and postoperative hypertrophic scar of the donor site were seen in one case each. Postoperative absorption of fascia were seen in two cases using Scarpa's fascia only. Conclusion: Secondary rhinoplasty using Scarpa's fascia is very useful method which offers a minimized donor site scar, low complication rate, shorter operation time and patient satisfaction and prevents the alopecia caused by the harvest of temporalis fascia.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.3
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• pp.253-258
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• 2004

To get accurate information about the defect from the test signal, NDT engineers should have a good knowledge on forward problems. Such knowledge is usually obtained by a lot of testing experiences. Another why of obtaining such knowledge is to build a database containing lots of defect information and their corresponding signals. However, the archiving of raw test data would require a lot of storage space. In this paper, an economic way of storing signals is studied by using Fourier descriptors. Instead of saving raw signal data, Fourier descriptors are saved and the storage spare is reduced. Of course, the defect signal can be reconstructed from the stored descriptors. By using differential ECT signals produced by numerical modeling and experiment, the savings of 85% from the original signal and $57{\sim}65%$ from the filtered signal in the storage space were confirmed. The similarity of the reconstructed signal and the original signal was also demonstrated. This Fourier descriptor approach could contribute significantly in building differential signal databases.

• Journal of Astronomy and Space Sciences
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• v.24 no.2
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• pp.167-178
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• 2007

We analysis the structure of Song $I-y\u{o}ng's$ Armillary Clock, a Korean National Treasure (No. 230) that is displayed at Korea University Museum. This Armillary Clock is only one remained in east Asia, but does not working because some parts had been broken away. We measured this remains and reconstructed a working model of the astronomical armillary sphere system of the his armillary clock, which system is consisted of Solar and lunar moving devices.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.4
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• pp.69-74
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• 2004

In this paper, we propose a novel method for improving defect-detection performance based on reconstruction of line-scan camera images using both the projection profiles and color space transform. The proposed method consists of RGB region segmentation, representative value reconstruction using the tracing system, and Y image reconstruction using color-space transformation. Through experiments it is demonstrated that the performance using the reconstructed image is better than that using aerial image for LCD surface inspection.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.173-176
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• 2001

Several dielectric as well as conducting cylinders buried in the lossy half space are reconstructed from the scattered fields measured along the interface between the air and the lossy ground. Iterative inversion method by using the hybrid optimization algorithm combining the genetic and the Levenberg-Marquardt algorithm enables us to find the positions, the sizes, and the medium parameters such as the permittivities and the conductivities of the buried cylinders as well as those of the background lossy half space. Illposedness of the inversion caused by the errors in the measured scattered fields are regularized by filtering the evanescent modes of the scattered fields out.

• Journal of Astronomy and Space Sciences
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• v.20 no.2
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• pp.153-162
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• 2003

Recently, we have reconstructed LX-200 12inch telescope system for tracking and observing man-made space object. Motor, motor driver and motion controller were up-graded for getting faster respond characteristic and active control available. Also, command signal was offered to the PID controller into motor driver as computed real orbiting information of objects using PC, and it's control period of command signal was reduced to the 20ms. As the result, slew speed of the mount system was in proved up to $18^{\circ}/sec$ and respond speed of the system was faster than that of commercial system. Also, flipping state of image observed could be minimized by the up-graded system.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.282-282
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• 2000

The analysis of the radiation effect on matter has been performed using stochastic methods. Recently, It was discovered that the detector pulses of radiation can be analysed using deterministic method that utilizes the chaotic behaviour with an attractor found in a noise region. We acquired a time series for pulse tram of Am-241 using scintillation detector and reconstructed a phase space, then performed new analysis for the radiation detection signal by applying embedding theory, Lyapunov exponent, correlation dimension, autocorrelation dimension, and power spectrum.