• Earthquakes and Structures
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• v.11 no.6
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• pp.1143-1164
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• 2016

Time Delay of Arrival (TDOA) estimation methods based on correlation function analysis play an important role in the micro-seismic event monitoring. It makes full use of the similarity in the recorded signals that are from the same source. However, those methods are subjected to the noise effect, particularly when the global similarity of the signals is low. This paper proposes a new approach for micro-seismic monitoring based on cross wavelet transform. The cross wavelet transform is utilized to analyse the measured signals under micro-seismic events, and the cross wavelet power spectrum is used to measure the similarity of two signals in a multi-scale dimension and subsequently identify TDOA. The offset time instant associated with the maximum cross wavelet transform spectrum power is identified as TDOA, and then the location of micro-seismic event can be identified. Individual and statistical identification tests are performed with measurement data from an in-field mine. Experimental studies demonstrate that the proposed approach significantly improves the robustness and accuracy of micro-seismic source locating in mines compared to several existing methods, such as the cross-correlation, multi-correlation, STA/LTA and Kurtosis methods.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.8
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• pp.1068-1076
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• 2001

The relations between wall pressure fluctuations and near-wall streamwise vortices are investigated in a spatially-developing turbulent boundary layer using the direct numerical simulation. The power spectra and two-point correlations of wall pressure fluctuations are presented to validate the present simulation. Emphasis is placed on the identification of the correlation between wall pressure fluctuations and streamwise vorticities. It is shown that wall pressure fluctuations are directly linked with the upstream streamwise vortices in the buffer region of the turbulent boundary layer. The maximum correlation occurs with the spanwise displacement from the location of wall pressure fluctuations. The conditionally-averaged vorticity field and the quadrant analysis of Reynolds shear stress indicate that the sweep events due to streamwise vortices generate positive wall pressure fluctuations, while negative wall pressure fluctuations are created beneath the ejection events and vortex cores. The instantaneous flow field and time records reveal that the rise of high wall pressure fluctuations coincide with the passages of the upstream streamwise vortices.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.219-222
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• 2006

최근 들어 ATSC-DTV의 미래형 핵심기술로 손꼽히고 있는 송신기 식별기술(TxID ; Transmitter Identification)이 새로운 신기술로 대두되고 있으며, 이에 대한 구현성 검증은 현재 활발하게 논의 중인 재생중계기(EDOCR)와 연계된 단일주파수망(SFN; Single Frequency Network)기술의 실용화를 위한 핵심적 역할을 한다고 볼 수 있다. 하지만 종래의 TxID기술은 긴 주기의 워터마킹용 확산코드를 사용하므로 수신기 입장에서 하드웨어 부피가 크게 증가되는 문제점을 갖고 있다. 따라서 본 논문에서는 TxID 수신기 하드웨어 부피를 크게 경감시킬 수 있는 새로운 Decimated Correlation 기법을 이용한 DTV TxID 수신 신호의 효율적인 신호처리 기법을 제시하였으며, 모의실험을 통한 성능평가를 통해 제안한 알고리즘의 유용성을 입증하였다.

• Research in Community and Public Health Nursing
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• v.16 no.4
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• pp.488-497
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• 2005

Purpose: This study examined the relation of BMI to lipid metabolism and health promoting behavior in middle-aged women. Methods: The subjects were 113 women between 40 to 60 years of age. The data was collected from April 2003 to July 2004. BMI was measured using body composition analyzer and lipid metabolism were measured using automatic biochemical analyzer. Health promoting behavior was collected using a structured questionnaire. The SPSSWIN(10.0 version) program was used to analyze the data and get the descriptive statistics and Pearson's correlation coefficients. Results: BMI was negatively correlated with HDL-c and positively correlated with triglyceride, but there was no significance between BMI and total cholesterol. There was no significance of correlation between BMI and total health-promoting behavior. Conclusion: This study showed that BMI is meaningful in the identification of the high risk women to prevent HDL-c & triglyceride metabolism disturbance, but additional research is needed to study the correlation between BMI and health promoting behaviors in middle-aged women.

• Journal of Korean Clinical Nursing Research
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• v.17 no.2
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• pp.215-227
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• 2011

Purpose: This research was done to identify relationships among job stress, fatigue, job satisfaction, and commitment to organization in emergency department nurses. Methods: Research participants were 513 nurses who worked in the emergency department of 17 tertiary centers and 28 secondary hospitals. Data collection for this descriptive correlational study was done from May to July 2010 using self report questionnaires, and analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficient with the SAS 9.2 program. Results: There were statistically significant differences in organizational commitment according to age, religion, total clinical experience, emergency department experience, current position, frequency of night shift, average sleep hours, wage level, numbers of beds in unit, and reason for working. A positive correlation was found between job stress and fatigue, and between job satisfaction and commitment to organization for the emergency department nurses and a negative correlation between job stress and Job satisfaction, and fatigue and Job satisfaction. Conclusion: Results of this research indicate that job stress in emergency department nurses was the principal variable affecting job satisfaction and commitment to organization along with fatigue. Appropriate stress management strategies based on identification of job stress for these nurses should lead to development of improved management of nursing manpower and a reduction in stress.

• Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.282-293
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• 2023

Nile perch and Nile tilapia are major commercial species in Uganda, and thus require continuous production. However, their production is impacted by anthropogenic activities such as fishing in breeding habitats. The aim of this study was to identify and characterize Nile perch and Nile tilapia fish breeding habitats on Lake Kyoga. Water quality, lake bottom, fish and vegetation type samples were collected from 20 sites in April of 2021 and 2022. Key informant interviews were conducted with experienced fishermen at five fish landing sites. The water quality parameters indicated significant difference within the sites using analysis of variance. Sandy and muddy bottom types were equally spread at 40% each by use of a pie chart. Fish gonads showed no significant difference among the 20 sites. Bivariate correlation analysis of the vegetation types indicated a strong negative correlation with Nile perch while Nile tilapia had a positive correlation. Principal component analysis of the water quality, fish gonads and habitat vegetation components cumulatively contributed 82.5% in characterizing a fish breeding habitat. Four sites for Nile perch and four sites for Nile tilapia were characterized as breeding sites on Lake Kyoga and are recommended for mapping and gazettement as breeding habitats for sustainable fisheries management.

• Journal of Broadcast Engineering
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• v.11 no.1 s.30
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• pp.100-106
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• 2006

In this paper, we proposed a TxID(Transmitter Identification) system using ZCD (Zero Correlation Duration) code as interference-cancelled spread codes for single frequency network of ATSC terrestrial DTV broadcasting. ZCD codes are simply implemented and have ZCD characteristics. Then, Proposal system can fundamentally solve interference problems caused by ICI(Inter Code Interference) and MPI(Multi-Path Interference) which happens in TxID system using spread coding method. Also, those can cancel truncated error which happens at watermarking for TxID since those can remove its period. In this paper, we identified the availability of TxID system applying interference-cancelled ZCD codes by analyzing DER (Detection Error Rate) which is simulated in various interference environments such as AWGN, ICI, and MPI.

• The Journal of Internal Korean Medicine
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• v.41 no.4
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• pp.624-643
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• 2020

Objectives: The aim of this study was to analyze the correlation between Ryodoraku and two pattern-identification questionnaires in patients with Burning Mouth Syndrome (BMS). Methods: The study participants were 30 patients with BMS who visited the Oral Diseases Clinic of Kyung Hee Oriental Medicine Hospital from June to November, 2019. The Ryodoraku test and two pattern-identification questionnaires were administered to all patients. Measurements included the average Ryodoraku score, which is called the Total Average (TA), and each score on the Ryodoraku point scale. The degree of Yin-deficiency, Qi-stagnation, and pain were assessed with the Yin-deficiency Questionnaire (YDQ), Qi-stagnation Questionnaire (QSQ), and Visual Analogue Scale (VAS), respectively. Results: The average TA score was 29.90. The LF5 (p=0.013) and RF5 (p=0.016) scores were lower than the TA scores, and the RH5 (p=0.020) and RH6 (p=0.006) scores were higher than the TA scores. A negative correlation was detected between the YDQ scores and the LH1 (r=-0.366, p=0.046), LH2 (r=-0.507, p=0.004), LH3 (r=-0.374, p=0.042), RH1 (r=-0.361, p=0.050), RH2 (r=-0.403, p=0.027) points. The LF5 (p=0.050) and RF2 (p=0.048) scores were lower in the patients with Qi-stagnation patients than without Qi-stagnation. Conclusions: Our results suggest that low TA and Ryodoraku scores on LF5 and RF5 and high Ryodoraku scores on RH5 and RH6 could be quantitative indicators for the diagnosis of BMS. The LH1, LH2, LH3, RH1, RH2, LF5, and RF2 scores could also be an indicators for diagnosis of Yin-deficiency and Qi-stagnation in patients with BMS.

• The Journal of Internal Korean Medicine
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• v.35 no.2
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• pp.157-174
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• 2014

Objectives : The aims of this study were to evaluate the diagnostic values of tongue coating thickness and sterno-costal angle as the quantitative diagnostic indicators in functional dyspepsia. Methods : We surveyed 60 functional dyspepsia patients recruited by the clinical trial, 'Clinical Trial for Evaluation on Availability of tongue diagnosis system (CTS-1000) : a Pilot study'. The patients were classified into three groups according to Rome III criteria for functional dyspepsia, and categorized into five groups according to Instrument of pattern identification for functional dyspepsia. Nepean dyspepsia index-Korean version (NDI-K) score, tongue coating thickness (percentage of tongue coating by tongue diagnosis system (CTS-1000), and weight of tongue coating by microbalance), sterno-costal angle, duration of illness and body mass index (BMI) were investigated. Results : Among the 5 types by instrument of pattern identification for functional dyspepsia, a significant difference of percentage of tongue coating was found. Percentage of tongue coating and weight of tongue coating showed significant correlation with total NDI-K score. Sterno-costal angle showed strong positive correlation with BMI and also showed significant difference between the non-overweight (BMI<23, n=32) and overweight ($BMI{\geq}23$, n=28) groups. Conclusions : Tongue coating thickness showed its potential as a new quantitative diagnostic indicator of functional dyspepsia. Further studies on the sterno-costal angle are anticipated to evaluate its potential as a new quantitative diagnostic indicator.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.1
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• pp.70-76
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• 2002

In this paper, we proposed a personal identification algorithm using the iris region which has discriminant features. First, we acquired the eye image with the black and white CCD camera and extracted the iris region by using a circular edge detector which minimizes the search space for real center and radius of the iris. And then, we localized the iris region into several circles and extracted the features by filtering signals on the perimeters of circles with one dimensional Gabor filter We identified a person by comparing ,correlation values of input signals with the registered signals. We also decided threshold value minimizing average error rate for FRR(Type I)error rate and FAR(Type II)error rate. Experimental results show that proposed algorithm has average error rate less than 5.2%.