• Proceedings of the KIEE Conference
• /
• 2003.07c
• /
• pp.1759-1761
• /
• 2003

Recently, the development of diagnosis technique with high confidence is important on power equipment, for this reason is use for measurement and analysis of PD with prior appearance of insulation breakdown In this paper, we presents the analysis of trouble signal to use ${\Phi}$-Q method which display 2D and 3D Equipment of simulation has made independently DS for 170kV GIS of one phase with same on field. The detected signal through the sensor of Induction and Acoustic Emission is classified to use characteristic neural network algorithm and then it is analysis.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.744-745
• /
• 2007

변압기를 진단하는 분석 요소 중 흔히 사용하는 방법으로 유중가스분석을 이용하는 방식을 많이 사용하고 있다. 유중가스 분석은 변압기 내 Oil이 열과 Arc등에 의해 화학적으로 변화된 것을 측정하여 열화 정도를 추정하는 방식이지만 신속한 검출 및 위치추정이 불가능하다는 단점이 있다. 신속한 검출이 되지 않으면 신속한 보고가 이루어 질 수 없으므로 변압기 교체시점을 맞추지 못하여 사고로 인한 막대한 피해보상이 발생한다. 이런 단점을 보완하기 위해 변압기내 부분방전 및 Arc에 의해 발생하는 부분방전신호를 초음파 대역에서 검출하여 열화 및 위치를 추정할 수 있는 초음파 분석이 필요하게 되었고 실험을 통해 변압기에 대한 분석, 진단을 시행하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11a
• /
• pp.400-405
• /
• 2005

The diagnosis of mechanical load and of power transmission system failures is usually carried out through mechanical signals such as vibration signals, acoustic emissions, motor speed envelope. If the mechanical load comes from an electrical machine the mechanical failures could be detected previously. Mechanical rotor imbalances and rotor eccentricities are reflected in electric, electromagnetic and mechanical quantities. Therefore, many surveillance schemes apply to the Fourier spectrum of a line current in order to monitor the motor condition. Due to the interaction of the currents and voltages, both these current harmonics are also reflected by a single harmonic component in the frequency spectrum of the electric power. Motor Current Signature Analysis is the usuful technique to assess machine electrical condition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.11a
• /
• pp.866-869
• /
• 2004

Power transformers, air-intakes and stacks in the urban combined power plant are main noisy sources. Because of Inhabitant complaint by abnormal noise transferred from the power plant. the noise was investigated at power plant and uptown area. The result of diagnosis made the acoustic resonance phenomenon by 580Hz's combustion dynamic pressure with the standing wave mode of sound fields in exhaust passageway of gas turbine into main noise source of public complain. The abnormal noise is caused by the resonance exhaust noise transferred through stacks of power plant.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.6 no.1
• /
• pp.9-15
• /
• 1995

Bowing of the vocal cords may be due to aging. atrophy. bilateral superior laryngeal nerve paralysis. injudicious vocal cord surgery, of an idiopathic cause. The bowing usually produces a dysphonia characterized by breathiness due to air escape : however, it can produce aphonia. This report reviews vocal function after surgical correction of bowing of the vocal cords for diagnosis and management. The vocal function of 13 patients with sulcus vocalis and 12 patients with vocal cord atrophy was evaluated with the use of a test battery of multidimensional evaluation items. The voice was improved postoperatively in most patients. The voice improvement was reflected objectively in maximum phonation time, mean air flow rate during phonation, stroboscopic findings. sound pressure level range and fundamental frequency range of phonation, and results of acoustic analyses of tape-recorded voice. The vocal function after surgical correction of the sulcus vocalis and vocal cord atrophy was improved postoperatively in most patient, but the results were not satisfactory.

• The Journal of Korean Medicine
• /
• v.24 no.4
• /
• pp.64-70
• /
• 2003

Background and Purpose : Allergic rhinitis is a well-known, relatively controllable chronic disease. Although a number of methods for treating allergic rhinitis have been tried, many patients have not been satisfied with their treatment. Therefore, this study tried to evaluate the effect of a cooperative system of Oriental and Western medicine and to develop a new diagnosis protocol for treatment of allergic rhinitis. Methods : We measured improvement rate and acoustic rhinometry after the allergeninduction test and performed a filter paper test as a nonspecific hypersensitivity test with 60 patients who are allergic to house dust mite. Patients were divided into two groups, one treated with Western medicine only and one treated with both Western and Oriental herbal medicine. For the group with Western medicine only, antihistamine for one week and local steroid medicine for two weeks were prescribed. For the group with combined medicine, Oriental herbal medicine was prescribed according to the patient s constitution, along with Western medicine. After all treatments, the above tests were re-performed and the improvement rate was compared. Results and Conclusion : We observed better results in the group treated with both Western and Oriental herbal medicines, comparing improvement rate and the alteration of total nasal volume through acoustic rhinometry after the allergen induction test. In the filter paper test, there was no significant difference between the two groups. In conclusion, we showed the additive effect of Oriental herbal medicine without any severe side effects compared with treatment with Western medicine only. In this study, we set only two patient groups, but further study is required to create various experimental groups and compare among them. We suggest that it might enhance understanding of the improved effect of Oriental herbal medicine in the therapy of allergic rhinitis.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.17 no.2
• /
• pp.127-132
• /
• 2006

Background and Objectives : Functional dysphonia is a voice disturbance in the absence of structural or neurologic laryngeal pathology characterized by voluntary misuse of laryngeal muscles. The present report reviews clinical characteristics of 25 patients with functional dysphonia. Materials and Method : We analyzed medical records, perceptual and acoustic analysis of voice samples, aerodynamic studies and laryngoscopy. Results : There was no sex or age predilection. Eighty four percent of patients presented sudden onset of symptoms and 76% had specific events at the onset. Most patients showed breathy or strained voice and various degree of vocal fold insufficiency with supraglottic compensatory contractions. Acoustic analysis revealed non-diagnostic, but mean flow rate was lower than normal in all cases. All patients responded to voice therapy except for 4 patients who were tort to follow up. Mean number of voice therapy sessions required to get responses is 1.9 sessions. Conclusion : We concluded that patients with functional dysphonia responded very well to short-term voice therapy and should be included in differential diagnosis in patients with dysphonia cannot be explained by structural or neurologic etiology.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.28 no.2
• /
• pp.106-111
• /
• 2017

Background and Objectives : The purpose of this study was to investigate the criterion-related concurrent validity of two standardized auditory-perceptual assessments and the Acoustic Voice Quality Index (AVQI) for measuring dysphonia severity in patients with vocal cord paralysis (VCP). Materials and Methods : Total 210 patients with VCP and 236 normal voice subjects were asked to sustain the vowel [a:] and to read aloud the Korean text "Walk". A 2 second mid-vowel portion of the sustained vowel and two sentences (with 26 syllables) were recorded. And then voice samples were edited, concatenated, and analyzed according to Praat script. Two standardized auditory-perceptual assessment (GRBAS and CAPE-V) were performed by three raters. Results : The VCP group showed higher AVQI, Grade (G) and Overall Severity (OS) values than normal voice group. And the correlation among AVQI, G, and OS ranged from 0.904 to 0.926. In ROC curve analysis, cutoff values of AVQI, G, and OS were <3.79, <0.00, and <30.00, respectively, and the AUC of each analysis was over .89. Conclusion : AVQI and auditory evaluation can improve the early screening ability of VCP voice and help to establish effective diagnosis and treatment plan for VCP-related dysphonia.

• The Journal of the Korea Contents Association
• /
• v.18 no.1
• /
• pp.108-116
• /
• 2018

The purpose of this study was to investigate the relationship between the differences in the acoustic measurements (AVQI) and the auditory-perceptual assessments (GRBAS, CAPE-V) of the normal and vocal fold nodules. For this purpose, Total 335 voice samples were analyzed acoustically and three raters performed auditory-perceptual assessments. in the results, AVQI, G, and OS scores of the normal group were lower than those of the vocal fold nodules group. The correlations between the G scale and the OS scale were highly correlated, and the correlation between the AVQI, and auditory-perceptual results (G and OS) was also high value. The threshold values for discriminating AVQI, G, and OS between the two groups were ${\leq}4.06$, ${\leq}1$, and ${\leq}26$, respectively, and the predictive diagnostic power was 0.840, 0.860, and 0.848. In conclusion, AVQI and auditory-perceptual evaluation can improve potentiality the screening of vocal fold nodules and help to determine the diagnosis and treatment plan of voice disorders.

• Journal of the Institute of Convergence Signal Processing
• /
• v.23 no.2
• /
• pp.84-90
• /
• 2022

Machine tool state monitoring is a process that automatically detects the states of machine. In the manufacturing process, the efficiency of machining and the quality of the product are affected by the condition of the tool. Wear and broken tools can cause more serious problems in process performance and lower product quality. Therefore, it is necessary to develop a system to prevent tool wear and damage during the process so that the tool can be replaced in a timely manner. This paper proposes a method for diagnosing five tool states using a deep learning-based hierarchical convolutional neural network to change tools at the right time. The one-dimensional acoustic signal generated when the machine cuts the workpiece is converted into a frequency-based power spectral density two-dimensional image and use as an input for a convolutional neural network. The learning model diagnoses five tool states through three hierarchical steps. The proposed method showed high accuracy compared to the conventional method. In addition, it will be able to be utilized in a smart factory fault diagnosis system that can monitor various machine tools through real-time connecting.