• The Journal of the Acoustical Society of Korea
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• v.34 no.3
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• pp.227-233
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• 2015

In this paper, we propose music and voice separation using kernel sptectrogram models backfitting based on log-spectral amplitude estimator. The existing method separates sources based on the estimate of a desired objects by training MSE (Mean Square Error) designed Winer filter. We introduce rather clear music and voice signals with application of log-spectral amplitude estimator, instead of adaptation of MSE which has been treated as an existing method. Experimental results reveal that the proposed method shows higher performance than the existing methods.

• Journal of Powder Materials
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• v.12 no.4 s.51
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• pp.291-295
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• 2005

CdSe hollow sphere with average size of about 30-50 nm was synthesized from the mixed solution of cadmium chloride $(CdCl_2)$, sodium selenosulfate $(Na_2SeSO_3)$ and ethylenediamine(EDA, $H_2NCH_2CH_2NH_2$) at room temperature. The molar ratio of EDA to $Cd^{2+}$ showed the most significant effect on the morphology of CdSe hollow sphere. This paper will present and discuss the possible formation mechanism of CdSe hollow sphere based on the observation of morphological changes.

• Journal of Pharmaceutical Investigation
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• v.25 no.2
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• pp.117-123
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• 1995

For the effective administration of narcotic antagonist, the application of sustained release implantable systems with biodegradable polyphosphazene was examined. Using poly[(diethyl glutamate)-co-(ethyl glycinate) phosphazene], the implantable devices containing naloxone hydrochloride were prepared and in vivo implantation studies were carried out subcutaneously in rat and rabbit with this preparation for the biocompatibility and pharmacokinetics. The histological finding in rats at initial time period was the inflammation that occurred focally around the implants, but they were showed subsequent mild and limited chronic inflammations and the irreversible changes such as necrosis and degeneration of the muscle or connective tissues were not observed. Therefore the placebo and naloxone implants are considered to be biocompatible formulations histologically. In pharmacokinetic studies, the release of naloxone from the naloxone implants into blood plasma was maintained in 192 hours, but the initial burst effect was observed. If this problem was solved, the application for the narcotic antagonist sustained release systems can be expected.

• Journal of Korean Society of Steel Construction
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• v.20 no.2
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• pp.347-354
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• 2008

Steel plate-concrete (SC) structure has recently been used in nuclear power structure because of its construction efficiency. In this study, experimental and analytical study to investigate the behavior of the SC structure's wall slab connection was carried out. Experiments were performed for typical SC and RC connections in order to examine the basic difference between each structure. Finite element analysis was performed and the result of the analysis was found to closely reflect the experimental result. By varying the thickness of the shear plate and friction coefficients and the distance of applied load from the wall, the influence of the parameters on the joint strength and failure modes were examined. Finally, it was confirmed that the joint strength formula proposed in th this research gives conservative results.

• Korean Journal of Materials Research
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• v.24 no.4
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• pp.186-193
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• 2014

A thin Cu seed layer for electroplating has been employed for decades in the miniaturization and integration of printed circuit board (PCB), however many problems are still caused by the thin Cu seed layer, e.g., open circuit faults in PCB, dimple defects, low conductivity, and etc. Here, we studied the effect of heat treatment of the thin Cu seed layer on the deposition rate of electroplated Cu. We investigated the heat-treatment effect on the crystallite size, morphology, electrical properties, and electrodeposition thickness by X-ray diffraction (XRD), atomic force microscope (AFM), four point probe (FPP), and scanning electron microscope (SEM) measurements, respectively. The results showed that post heat treatment of the thin Cu seed layer could improve surface roughness as well as electrical conductivity. Moreover, the deposition rate of electroplated Cu was improved about 148% by heat treatment of the Cu seed layer, indicating that the enhanced electrical conductivity and surface roughness accelerated the formation of Cu nuclei during electroplating. We also confirmed that the electrodeposition rate in the via filling process was also accelerated by heat-treating the Cu seed layer.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.67-72
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• 2010

This paper presents biometrical driver verification system in car experiment through analysis of speech, and face information. We have used Mel-scale Frequency Cesptral Coefficients (MFCCs) for speaker verification using speech information. For face verification, face region is detected by AdaBoost algorithm and dimension-reduced feature vector is extracted by using principal component analysis only from face region. In this paper, we apply the extracted speech- and face feature vectors to an SVM kernel with Gaussian Mixture Models(GMM) supervector. The experimental results of the proposed approach show a clear improvement compared to a simple GMM or SVM approach.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.4
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• pp.33-38
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• 2009

This paper proposes an automatic equalizer control method in automobile audio system. The proposed method discriminates the music segment from the consecutive real-time audio stream of the radio and the equalizer is controlled automatically according to the classified genre of the music segment. For enhancing the accuracy of the music genre classification in real-time, timbre feature and rhythm feature extracted from the consecutive audio stream is applied to GMM(Gaussian mixture model) classifier. The proposed method evaluates the performance of the music genre classification, which classified various audio segments segmented from the audio signal of the radio broadcast in automobile audio system into one of five music genres.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.1
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• pp.81-87
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• 2013

In this paper, we propose a music search algorithm for automotive infotainment system. The proposed method extracts fingerprints using the high peaks based on log-spectrum of the music signal, and the extracted music fingerprints store in cloud server applying a hash value. In the cloud server, the most similar music is retrieved by comparing the user's query music with the fingerprints stored in hash table of cloud server. To evaluate the performance of the proposed music search algorithm, we measure an accuracy of the retrieved results according to various length of the query music and measure a retrieval time according to the number of stored music database in hash table.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.50-55
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• 2020

This study investigates the injection molding of a plastic rack gear and focuses on deflections in the part. The causes of deflections were found and resolved through a trade-off study by injection molding analysis. Based on a warpage analysis, the fiber orientation was found to be a dominant factor in the occurrence of deflections. Changes in the part design and various injection conditions were analyzed for their effects in reducing deflections. Based on the trade-off study, a new part bottom design, injection time, and melt temperature were recommended. A trial injection was done for the new plastic rack gear, and measurements showed that its flatness surpassed that of the original part and met the specified requirement. The short injection time, low melt temperature, and symmetric similar configuration of the part contributed to the reduction in deflections. Therefore, optimized gate design and injection conditions as well as a new part design were validated through injection molding analysis in this study.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.101-107
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• 2008

Due to increased interest in environmental friendly ecological development and restoration, civil appeals concerning various environmental and landscape problems are continuously being lodged in cases where open-pit limestone mines are situated in places with eminent natural landscape. In this study, with the open-pit limestone mines located in the Baekdu mountain range as a study area, intends to contribute in recognition of various environmental problems and in the promotion of a reasonable restoration plan through high quality geo-spatial information. And it is planning to establish a method for sustained monitoring of the limestone mining by building intelligent national land information of the study area through combining Airborne Laser Scanning and Terrestrial LiDAR based surveying.