• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.100-101
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• 2021

In Korea, which has entered an aging society, 87% of the elderly population suffers from chronic diseases such as dementia and stroke, of which Alzheimer's dementia accounts for 71.3% of all dementia. In this paper, labeling verification was performed to review the error problem of deep learning results divided by Alzheimer's dementia MRI image into three stages.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.5
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• pp.466-472
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• 2009

An acoustic leak monitoring system(ALMS) using acoustic emission(AE) technique was applied for leakage detection of nuclear power plant's pipeline which is operated in high temperature and pressure condition. Since this system only monitors the existence of leak using the root mean square(RMS) value of raw signal from AE sensor, the difficulty occurs when the characteristics of leak size and shape need to be evaluated. In this study, dual monitoring system using AE sensor and accelerometer was introduced in order to solve this problem. In addition, artificial neural network(ANN) with Levenberg.Marquardt(LM) training algorithm was also applied due to rapid training rate and gave the reliable classification performance. The input parameters of this ANN were extracted from varying signal received from experimental conditions such as the fluid pressure inside pipe, the shape and size of the leak area. Additional experiments were also carried out and with different objective which is to study the generation and characteristic of lamb and surface wave according to the pipe thickness.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.3
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• pp.238-243
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• 2008

Several experimental techniques for identifying the noise sources distributed over a moving vehicle have been developed recently and are used to design a low noise vehicle. The beamforming method, which uses phase information between several microphones to localize the source position, is proved to be one of the promising techniques applicable even under complicated test environments. In this study a beamforming algorithm is developed and applied to measure the dominant noise sources on a passenger car passing by. Unlike the acoustic signals from a stationary noise source, the sound generated from a moving source is distorted due to the Doppler effects. The information about the speed and relative position of the vehicle are used to eliminate the Doppler effects from the measured acoustic signal by using a de-Dopplerization algorithm. The noise generated from a moving vehicle can be grouped in many ways, however, tire noise and the noise generated from the engine are distinguishable at the speeds being tested.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1042-1049
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• 2000

Irradiation-induced volatile flavor compounds in irradiated (1, 3, 5, 10 kGy) beef were analyzed by liquid liquid continuous extraction (LLCE) and gas chromatography/mass spectrometry (GC/MS) methods. One hundred fifty volatile compounds were detected in irradiated beef. These compounds were composed mainly of 71 hydrocarbons, 35 aromatic compounds, 15 aldehydes, 7 ketones, 4 acids, 6 esters and 12 miscellaneous compounds. Among these, only 6 volatile compounds including (E) -2-hexenal, nonene, 2-nonenal, cyclodecene, dodecene and cyclododecene were detected as irradiation-induced volatile flavor compounds, comparing with unirradiated beef meat. However, 4 volatile compounds, such as cyclodecene (r=0.88), (E)-2-hexenal (r=0.85), nonene (r=0.74) and 2-nonenal (r=0.70), having a positive correlation coefficient with the increment of irradiation dose, were considered as marker compounds for detecting irradiation dosages in irradiated beef.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.498-509
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• 2023

Purpose: This paper proposes a method detecting the falling of a maintenance worker in the underground utility tunnel, by applying deep learning techniques using CCTV video, and evaluates the applicability of the proposed method to the worker monitoring of the utility tunnel. Method: Each rule was designed to detect the falling of a maintenance worker by using the inference results from pre-trained YOLOv5 and OpenPose models, respectively. The rules were then integrally applied to detect worker falls within the utility tunnel. Result: Although the worker presence and falling were detected by the proposed model, the inference results were dependent on both the distance between the worker and CCTV and the falling direction of the worker. Additionally, the falling detection system using YOLOv5 shows superior performance, due to its lower dependence on distance and fall direction, compared to the OpenPose-based. Consequently, results from the fall detection using the integrated dual deep learning model were dependent on the YOLOv5 detection performance. Conclusion: The proposed hybrid model shows detecting an abnormal worker in the utility tunnel but the improvement of the model was meaningless compared to the single model based YOLOv5 due to severe differences in detection performance between each deep learning model

• Journal of Yeungnam Medical Science
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• v.13 no.2
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• pp.279-294
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• 1996

This study was carried out to develop a Korean language version of Zung's self-rating anxiety scale(SAS) from august, 1994 to September, 1996. The subjects consisted of 205 normal control subjects from the general population group, and 97 subjects with anxiety disorders. These 97 subjects were chosen from a group by the structured clinical interview for DSM-IV of in patients and out patients. Both normal control subjects and anxiety disorder subjects were drawn utilizing a cluster of sampling methods. In order to analyze the data on anxiety scores, Pearson's product moment correlation coefficient method was carried out, as well as reliability, factor analysis and discriminant function analysis, utilizing the SPSS/PC+ program. The results obtained were as follows: The mean average of the total anxiety scores were 32.36 + 6.35 for the normal control subjects and 50.53 + 7.67 for anxiety disorder subjects. Test-retest reliability(coefficient r=0.98, p < 0.001), and internal consistency(coefficient r=0.96, p < 0.001) were satisfactory. Factor analysis using oblique technique rotation yielded four factors. The normal control subjects scored higher concerning the symptoms such as sweating, restlessness, apprehension, insomnia and dyspnea, and lower for faintness, mental disintegration, paresthesia, dizziness and tremor. On the other hand, for the anxiety disorders, apprehension, restlessness, sweating, dyspnea and insomnia scored higher, and lower for faintness, paresthesia, nightmare, dizziness and tremor.

• The korean journal of orthodontics
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• v.25 no.2 s.49
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• pp.153-163
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• 1995

In this study, Receiver Operating Characteristic(ROC) analysis was used to evaluate the ability of cephalometric measurements to identify patients with Class III malocclusions. ROC analysis is the method for determining the validity of a diagnostic measure and for evaluating the relative value of diagnostic tests. The sample consisted of 496 patients with malocclusion. Class III malocclusion is defined as the dental relationship for which The mesiobuccal groove of the lower first molar is deviated mesially from the mesiobuccal cusp of the upper first molar. Of the total sample of 496 patients, 245 had Class III malocclusions. 16 cephalometric measurements were selected, each of which was treated as a diagnostic test. The ROC curves were generated for each cephalometric measurement with intervals of $1.0^{\circ}$ for angular measurements, 1.0mm for linear measurements. The area under the ROC curves was measured for direct comparison among different diagnostic tests. The results were as follows; 1. The 'Wits' appraisal was found to be a better diagnostic criterion for the presence of Class III malocclusion than any other commonly'used cephalometric measurement. 2. AB plane angle, ANB angle, App-Bpp distance, AF-BF distance, APDI, Distance of point A and Pog to N perpendicular, maxillomandibular differential had high diagnostic value. 3. Cephalometric measurements which evaluate the position of the mandible had moderate diagnostic value. 4. Cephalometric measurements related to the maxilla discriminated least between patients with and without Class III malocclusion.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.22.4-22.4
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• 2011

위성항법시스템에서 위성 신호의 이상 발생 시 신속하게 위성시계의 고장 유무를 판단할 수 있도록 실시간 위성 시계 이상감지 시스템을 구축하였다. 위성 시계는 시스템 성능에 직접적인 영향을 미치는 핵심 요소로서 고장이나 이상 발생 시 측정치에 매우 큰 영향을 미칠 수 있다. 특정 위성 시계에 고장이나 이상이 발생한 경우 사용자들이 해당 위성의 측정치를 사용하지 않도록 가능한 빨리 이를 감지하고 공지할 수 있어야 한다. 현재 GPS의 경우 시스템 자체만으로는 위성 상태 정보가 적절한 시간 내에 제공되지 못하므로, 사용자가 직접 위성 신호의 사용 유무를 판단할 수 있는 위성 상태 감시 기능이 필요하다. 이 논문에서는 위성 시계 이상 발생 시 이를 실시간으로 감지할 수 있도록 한국항공우주연구에서 구축한 실시간 위성 시계 이상 감지 시스템에 대해 소개하고자 한다. 시스템 구현을 위해 적용한 방법은 크게 세 단계로 나뉠 수 있다. 첫 번째, 실시간으로 수신한 GPS 이중 주파수 측정치로부터 반송파 스무딩 필터를 적용하여 위성 시계 바이어스를 추정한다. 두 번째, 위성 위치 및 시계 정보의 실시간 적용을 위해 항법력보다 성능이 뛰어난 IGS Ultra-rapid 예측 정보를 활용한다. 마지막으로 위성시계 바이어스 추정치와 예측치를 비교하여 시계 이상 유무를 판별한다. 실제 위성 시계 이상이 발생한 위성의 측정치를 적용하여 시스템에 대한 검증시험을 수행하였고, 10 나노 초 수준의 위성 시계도약 현상이 발생한 위성의 감지를 통해 시스템의 성능을 확인하였다. 이는 항공항법분야와 같이 고성능의 위치 정보를 요구하는 응용분야에 신뢰성 있는 위성 정보 제공을 위해 활용될 수 있다.

• Food preservation and processing industry
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• v.7 no.2
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• pp.33-36
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• 2008

차는 차나무 잎을 가공한 것으로 녹차 등의 비발효차, 우롱차 등의 반발효차, 홍차 등의 발효차로 분류된다. 우롱차, 홍차 등의 발효는 미생물이 관여하는 발효가 아니고 찻잎에 존재하는 효소에 의한 반응을 이용하므로 효소 발효차로 불리운다. 반발효차는 $10{\sim}65%$ 발효도 그리고 발효차는 85% 이상의 발효도 제품으로 통상 정의되나 발효정도를 판단할 수 있는 기준이 설정되어 있지 않아 발효도 100%에 해당되는 위치를 구명하여 발효차 발효정도 판별 기준으로 활용하고자 발효과정 중 일어나는 성분과 색조의 변화를 검토하였다. 적색도(a 값)와 황색도(b 값)는 위조 및 유념 과정에서부터 색을 띠기 시작하여 발효 진행과 함께 증가하여 발효 시작 일정시간 후 최고점에 도달하고 이후 감소를 보였다. 가시영역의 녹차와 홍차의 스펙트럼에서 가장 큰 차이를 보인 420 nm 흡광도 값은 발효 진행과 함께 증가되어 일정시간 후 최고점에 도달하고 이후 감소를 보였다. 찻잎 성분 중 카테킨류는 5종이 검출되었는데 발효 진행과 함께 모두 급격히 감소하였다. 그러나 카페인은 발효 진행과 관계없이 거의 일정 수준을 유지하여 카페인은 효소 발효에 의해 변환되지 않는 성분으로 확인되었다. 4종의 테아플라빈류는 발효 0%에 해당하는 녹차에는 검출되지 않았으나 발효 진행과 함께 생성됨이 확인되었다. 테아플라빈류는 4종이 검출되었는데 이중 생성량이 많은 것은 TF3,3'G와 TF3G 순이었으며 이 성분들은 발효의 진행과 함께 일정시간 후 최고점에 도달하고 이후 감소를 보였다. 발효차 제조과정 중 발효에 의해 생성되는 적색과 황색 그리고 420 nm의 흡광도 값 그리고 발효에 의해 생성되는 TF3,3'G와 TF3G 생성 최고점에 이르는 발효시간이 일치함이 발견되었다. 이 최고점은 발효도 100%에 해당하는 위치로 판단된다.

• Journal of Yeungnam Medical Science
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• v.7 no.2
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• pp.89-96
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• 1990

The purpose of this article was to determine the discriminant function analysis of the Korean Wechsler Intelligence Scale(KWIS) for 110 normal controls and 98 schizophrenics. Of special interest was to verify the clinical discriminant power of two subtests of the KWIS(Vacabulary and Digit Symbols) and Zung' s Self-rating Anxiety Scale(SAS). Four major hypotheses were postulated. The normal control group would show higher scores than the schizophrenics ; mean scores on both Vocabulary and Digit Symbol. The mean difference in Digit Symbol between the two groups would be greater than that in the Vacabulary. There would be no significant relation among Digit Symbol. Vacabulary. and Anxiety. The most powerful discriminant power would be expected from subtest of Digit Symbol. The mean discriminant scores were - 1.34425 for the control subjects. 1.34425 for the schizophrenics. The correctly discriminated percentage was 89.1% for the control subjects. 90.8% for the schizophrenics. From the findings it was concluded that both Digit Symbol and Vocabulary scales had strong diagnostic value but the former was more powerful than the latter. However. the Anxiety scales had less diagnostic value.