• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1154-1157
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• 2004

During normal machine operation, partial discharge(PD) measurements were performed with turbine generator analyzer(TGA) in imitation stator winding of high voltage motors. The motor was energized to 4.47kV, 6.67, respectively. Applied voltage to Imitation winding was used two voltage level, 4.47[KV]and 6.67[KV]. Motors having imitation stator winding were installed with 80pF capacitive couplers at the terminal box Case of PD Pattern regarding applied voltage phase angel, the PD patterns were displayed two dimensional and three dimensional. TGA summarizes each plot with two quantities such as the normalized quantity number(NQN) and the peak PD magnitude(Qm). As the result, we could discrimidate using TGA the difference of internal and surface discharge for imitation stator winding. We have used the other technique, in order to feature extraction of faulty signals on stator winding, Daubechies Discrete wavelet transform and Harmonics analysis(FFT) about faulty signals.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.9-17
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• 2017

This paper describes a process of developing commercial real time image recognition system with company. In this paper we will make a system that is combining an empirical kernel map method and conjugate least squares support vector machine in order to represent images in a low-dimensional subspace for real time image recognition. In the traditional approach calculating these eigenspace models, known as traditional PCA method, model must capture all the images needed to build the internal representation. Updating of the existing eigenspace is only possible when all the images must be kept in order to update the eigenspace, requiring a lot of storage capability. Proposed method allows discarding the acquired images immediately after the update. By experimental results we can show that empirical kernel map has similar accuracy compare to traditional batch way eigenspace method and more efficient in memory requirement than traditional one. This experimental result shows that proposed model is suitable for commercial real time image recognition system.

• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.127-132
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• 2014

This paper describes a robust speech recognition technique by reconstructing spectral components mismatched with a training environment. Although the cluster-based reconstruction method can compensate the unreliable components from reliable components in the same spectral vector by assuming an independent, identically distributed Gaussian-mixture process of training spectral vectors, the presented method exploits the temporal dependency of speech to reconstruct the components by introducing a hidden-Markov-model prior which incorporates an internal state transition plausible for an observed spectral vector sequence. The experimental results indicate that the described method can provide temporally consistent reconstruction and further improve recognition performance on average compared to the conventional method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.4
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• pp.890-895
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• 2005

Dynamic (On-line) signature verification system consists of preprocessing, feature extraction, comparison and decision process for internal processing, and registration and verification windows for the user interface. We describe an implementation and design for an advanced dynamic signature verification system. Also, we suggest the method of feature extraction, matching algorithm, efficient user interface and an objective criteria for evaluating the performance.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.112-116
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• 2004

On-line monitoring of fault discharge is an important approach for indicating the condition of electrical insulation of stator winding in high voltage motor. In this paper, several key aspects of on-line monitoring system are discussed, involving the characteristics of fault discharge of stator winding in high voltage motor, spectrum analysis of four simulation fault signals, feature extraction of internal fault discharge from apply voltage to breakdown. The study of the partial discharge activities allows to highlight the ageing stage in the winding fault under test. During the life of the winding insulation fault, the shape of PD signal change relating to the ageing stage. The ageing of stator winding insulation fault of high voltage motor is investigated based on the characteristics of partial discharge pulse distribution and statistical parameters, such as maximum, skewness and kurtosis using discrete wavelet transform coefficients.

• Tuberculosis and Respiratory Diseases
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• v.77 no.4
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• pp.178-183
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• 2014

Here, we report a case of pulmonary paragonimiasis that was improved with initial anti-tuberculosis (TB) therapy but confused with reactivated pulmonary TB. A 53-year-old Chinese female presented with a persistent productive cough with foul smelling phlegm and blood streaked sputum. Radiologic findings showed subpleural cavitary consolidation in the right upper lobe (RUL). Bronchoscopic and cytological examination showed no remarkable medical feature. She was diagnosed with smear-negative TB, and her radiologic findings improved after receiving a 6-month anti-TB therapy. The chest CT scans, however, obtained at 4 months after completion of anti-TB therapy showed a newly developed subpleural consolidation in the RUL. She refused pathologic confirmation and was re-treated with anti-TB medication. Nevertheless, her chest CT scans revealed newly developed cavitary nodules at 5 months after re-treatment. She underwent thoracoscopic wedge resection; the pathological examination reported that granuloma caused by Paragonimus westermani. Paragonimiasis should also be considered in patients assessed with smear-negative pulmonary TB.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.184-192
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• 2022

Valve internal leakage is caused by damage to the internal parts of the valve, resulting in accidents and shutdowns of the piping system. This study investigated the possibility of a real-time leak detection method using the acoustic emission (AE) signal generated from the piping system during the internal leakage of a butterfly valve. Datasets of raw time-domain AE signals were collected and postprocessed for each operation mode of the valve in a systematic manner to develop a data-driven model for the detection and classification of internal leakage, by applying machine learning algorithms. The aim of this study was to determine whether it is possible to treat leak detection as a classification problem by applying two classification algorithms: support vector machine (SVM) and convolutional neural network (CNN). The results showed different performances for the algorithms and datasets used. The SVM-based binary classification models, based on feature extraction of data, achieved an overall accuracy of 83% to 90%, while in the case of a multiple classification model, the accuracy was reduced to 66%. By contrast, the CNN-based classification model achieved an accuracy of 99.85%, which is superior to those of any other models based on the SVM algorithm. The results revealed that the SVM classification model requires effective feature extraction of the AE signals to improve the accuracy of multi-class classification. Moreover, the CNN-based classification can be a promising approach to detect both leakage and valve opening as long as the performance of the processor does not degrade.

• Journal of KIISE:Software and Applications
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• v.29 no.3
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• pp.167-179
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• 2002

In this paper, we propose a new acoustic model for characterizing segmental features and an algorithm based upon a general framework of hidden Markov models (HMMs) in order to compensate the weakness of HMM assumptions. The segmental features are represented as a trajectory of observed vector sequences by a polynomial regression function because the single frame feature cannot represent the temporal dynamics of speech signals effectively. To apply the segmental features to pattern classification, we adopted segmental HMM(SHMM) which is known as the effective method to represent the trend of speech signals. SHMM separates observation probability of the given state into extra- and intra-segmental variations that show the long-term and short-term variabilities, respectively. To consider the segmental characteristics in acoustic model, we present segmental-feature HMM(SFHMM) by modifying the SHMM. The SFHMM therefore represents the external- and internal-variation as the observation probability of the trajectory in a given state and trajectory estimation error for the given segment, respectively. We conducted several experiments on the TIMIT database to establish the effectiveness of the proposed method and the characteristics of the segmental features. From the experimental results, we conclude that the proposed method is valuable, if its number of parameters is greater than that of conventional HMM, in the flexible and informative feature representation and the performance improvement.

• The Journal of Internal Korean Medicine
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• v.27 no.1
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• pp.208-220
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• 2006

Objective: Eosinophils are typically characterized by a bilobar nucleus with highly condensed chromatin and cytoplasm containing two major types of granules, specific and primary granules, and lipid bodies. The role of inflammation in asthma and other allergic diseases of the airways is widely appreciated, and airway inflammation is now included as a defining feature of asthma. The importance of the presence of eosinophils in the airways of patients with fetal asthma has long been recognized, but the mechanism by which these cells are recruited and retained in the lungs are only now being elucidated. Eotaxin is a potent and specific eosinophil chemoattractant that is mobilized in the respiratory epithelium after allergic stimulation. Methods : Water extracts of Armeniacae Amarum Semen(AAS) and pulmonary epithelial cell lines A549(alveolar typeII epithelial cells) and human eosinophils were used. Cytotoxic effects of AAS and MIS assay were estimated, as well as the effects of AAS on chemokines from prestimulated A549 cells by sandwich ELISA and RI-PCR. Chemotaxis assay was conducted on prestimulated eosinophils treated with AAS. Results : In this study it is demonstrated that $TGF-{\alpha}$, IL-4 and $IL-1{\beta}$ induced the accumulation of chemokine mRNAs in the alveolar epithelial cell lines A549 in dose-dependent manner. Eotaxin and IL-8 were inhibited by AAS in dose-dependent manner(p<0.05). Eosinophil migration was inhibited at high concentrations of AAS(p<0.05). Conculusions : These findings are indicative of suppression of eotaxin and IL-8, and suggest that this is accomplished through AAS treatment. This raises the possibility that AAS is of therapeutic value in diseases such as asthma.

• Tuberculosis and Respiratory Diseases
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• v.41 no.2
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• pp.152-157
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• 1994

Histiocytosis-X is a tenn used to define three diseases with similar morphologic characteristics : Letterer-Siwe diseae, Hand-Schuller-Christian disease and Eosinophilic granuloma. In general, they differ in terms of their age of onset, severity of clinical course and site of involvement. Eosinophilic granuloma typically is seen in young adults. Eosinophilic granuloma is diagnosed in the presense of diffuse pulmonary infiltrate, bony involvement. However, the pulmonary radiologic findings of eosinophilic granuloma are variable accordinary to stage of disease. therefore pathologic diagnosis of involving site is essential for confirmative diagnosis of eosinophilic grananuloma. Pathologically. the three disease are characterized by granulomatous infiltration of alveolar septa and bronchial walls and often involvement of bone. The hallmark of this disease is proliferation of the Langerhans' cell. The identifying feature is the X-body or Birbeck granule that is present in Langerhans' cells and histiocytic cells found in the lung of EG patient. We report a case of bilatera1, recurrent and spontaneous pneumothoraces in a 21 year old man with pulmonary histiocytosis-X, which is confirmed by eosinophilc granuloma in bone marrow biopsy and ultrastructural examination in cells obtained from BAL.