• Journal of the Korean Data and Information Science Society
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• 제17권4호
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• pp.1151-1160
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• 2006

The similarity weight, the pearson's correlation coefficient, which is used in the recommender system has a weak point that it cannot predict all of the prediction value. The similarity weight, the vector similarity, has a weak point of the high MAE although the prediction coverage using the vector similarity is higher than that using the pearson's correlation coefficient. The purpose of this study is to suggest how to raise the prediction coverage. Also, the MAE using the suggested method in this study was compared both with the MAE using the pearson's correlation coefficient and with the MAE using the vector similarity, so was the prediction coverage. As a result, it was found that the low of the MAE in the case of using the suggested method was higher than that using the pearson's correlation coefficient. However, it was also shown that it was lower than that using the vector similarity. In terms of the prediction coverage, when the suggested method was compared with two similarity weights as I mentioned above, it was found that its prediction coverage was higher than that pearson's correlation coefficient as well as vector similarity.

• 한국잠사곤충학회지
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• 11호
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• pp.73-80
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• 1970

This study was carried out in order to investigate the correlation among test items of export raw silk. The results obtained from the study are summarized as follows. 1. The highest correlation was between evenness and low evenness in case of the filaments made of autumn cocoons and the coefficient of correlation was 0.854. 2. Among following items, viz.; evenness and cleanness, neatness and low neatness and elongation and cohesion, the correlation phisically was not acknowledged, but the coefficients of correlation were high figures. 3. Poor correlation existed between following items, viz.; size deviation and maximum deviation, evenness and low evenness, neatness and low neatness, cleanness and low neatness. 4. It is considered that the high correlation exists between tenacity and elongation, but in this study the correlation existed among some items. 5. In this study it is a new fact that the correlation between neatness and cohesion as well as low neatness and tenacity existed enough highly. 6. As a conclusion the independence of ten items tested at present was acknowledged.

• 한국전자파학회논문지
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• 제26권4호
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• pp.349-356
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• 2015

본 논문은 LTE Band 5(824~894 MHz)에서 모노폴 타입과 슬롯 타입을 적용하여 저상관도를 갖는 MIMO(Multiple-Input Multiple-Output) 안테나 설계를 제안한다. 두 안테나 사이의 상관도 성능을 향상시키기 위하여 설치되는 그라운드의 특성 모드 이론에 기초하여 안테나의 형태를 서로 다르게 제작하였다. 논문에서 제안하는 MIMO 안테나는 각각 PIFA와 슬롯 안테나로 구성되어 있고, 두 개 모두 PIFA(Planar Inverted F Antenna)로 제작한 경우와 상관도 성능을 비교하였다. 서로 다른 구조의 두 개의 PIFA 타입으로 제작된 MIMO 안테나의 평균 상관 계수는 0.71로 매우 높았으나, 본 논문에서 제안된 MIMO 안테나는 0.17로 상관도 특성이 매우 낮아짐을 확인할 수 있었다.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2006년도 추계 학술발표회 논문집
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• pp.119-128
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• 2006

The similarity weight, the pearson's correlation coefficient, which is used in the recommender system has a weak point that it cannot predict all of the prediction value. The similarity weight, the vector similarity, has a weak point of the high MAE although the prediction coverage using the vector similarity is higher than that using the pearson's correlation coefficient. The purpose of this study is to suggest how to raise the prediction coverage. Also, the MAE using the suggested method in this study was compared both with the MAE using the pearson's correlation coefficient and with the MAE using the vector similarity, so was the prediction coverage. As a result, it was found that the low of the MAE in the case of using the suggested method was higher than that using the pearson's correlation coefficient. However, it was also shown that it was lower than that using the vector similarity In terms of the prediction coverage, when the suggested method was compared with two similarity weights as I mentioned above, it was found that its prediction coverage was higher than that pearson's correlation coefficient as well as vector similarity.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.1306-1310
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• 2009

The roughness coefficients were estimated by the Manning's equation for the measured stage and flow velocity of Bocheong stream basin in Kum river. The relationships between the estimated roughness coefficients and the geomorphologic factors were formulated by the linear, logarithmic, exponential and power type function, thereafter correlation equations were presented. The correlation analysis was performed between the measured stream length and the basin area of Bocheong stream basin by the linear, logarithmic, exponential and power type function, and correlation equation for the stream length was given. The roughness coefficient has strong correlationship with stream slope, but low correlation coefficients with stream length and basin area. For the correlationship with the roughness coefficients and the stream slope, the logarithmic type function has the smallest correlation coefficient, on the other hand, the exponential type function has the largest correlation coefficient. For the relationship between the stream length and the basin area, the correlation coefficient of the logarithmic type function shows the smallest value, linear type function shows the largest value.

• 음성과학
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• 제10권2호
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• pp.249-258
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• 2003

This study attempted to examine a speaker identification method using difference sum and correlation coefficient determined from a pair of intensity level matrices of band-pass-filtered numeric sounds produced by ten female speakers of similar age and height. Subjects recorded three digit numbers at a quiet room at a sampling rate of 22 kHz on a personal computer. Collected data were band-pass-filtered at five different band ranges. Then, matrices of five intensity levels at 100 proportional time points were obtained. Pearson correlation coefficients and the sum of absolute intensity differences between a pair of given matrices were determined within and across the speakers. Results showed that very high correlation coefficient and small difference sum generally occurred within each speaker but some individual variation was also observed. Thus, the matrix pair with a higher coefficient and a smaller difference sum was averaged to form each individual's model. Comparison among the speakers yielded generally low coefficients and large differences, which suggests successful speaker identification, but among them there were a few cases with very high coefficients and small differences. Future studies will focus on finer band ranges and additional spectral parameters at some peak points of the intensity contour at a low frequency band.

• 대한한의진단학회지
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• 제10권2호
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• pp.104-120
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• 2006

Background : Pulse-respiration ratio has been used for estimating subject's status in oriental medicine. Pulse and respiration is strongly associated with autonomic nerve system. But there is no research about correlation between pulse-respiration ratio and autonomic nerve system. Objectives : We performed this study to know correlation between pulse-respiration ratio and HRV(heart rate variability) that shows autonomic nerve system status well and to clarify clinical meaning of pulse-respiration ratio. Methods : After subject's 10 minutes rest, we measured subject's ECG, respiration pattern and HRV. In this research, subject's number is 95(Male 50/Female 45). We calculated pulse-respiration ratio from ECG and respiration pattern. Then, we analyzed correlation between pulse-respiration ratio and HRV parameters in all subjects, 2 group divided by Wan-Maek(P-R ratio 4.28). We tried to compare HRV parameters among Wan-Maek, Sak-Maek and Ji-Maek group. Correlation analysis between pulse-respiration Ratio and Pulse rate, respiration rate is performed. Finally correlation analysis between Respiration and HRV parameters in all subjects, 2 group divided by Wan-Maek(4.28) is studied. Results : 1. Mean pulse-respiration is 4.10${\pm}$0.67, Mean pulse rate is 68.06${\pm}$7.82bpm, Mean respiration rate is 16.81${\pm}$2.72 times per minute in all subjects. 2. Correlation analysis between pulse-respiration ratio and HRV parameters of high pulse-respiration ratio group is not significant. But, in low pulse-respiration ratio group, HFnorm(correlation coefficient 0.306, p= 0.018), lnHF (0.308, p=0.002) is significantly correlated with pulse-respiration ratio. 3. Comparison of HRV parameters among Wan-Maek, Sak-Maek and Ji-Maek Group is not significant. 4. Pulse-respiration ratio is more affected by respiration rate(correlation coefficient-0.17, p=0.000) than pulse rate (correlation coefficient 0.396, p=0.000). 5. Correlation analysis between respiration rate and HRV parameters of high pulse-respiration ratio group is not significant. But, in low pulse-respiration ratio group, HFnorm (correlation coefficient -0.327, p=0.011), LF/HF(0.346, p=0.007), lnHF (-0.355, p=0.006) are significantly correlated with respiration rate. Conclusion : Pulse-respiration ratio and parasympathetic index has positive correlation. The closer Wan-Maek, The higher parasympathetic index in low pulse-respiration ratio group. Respiration rate is more related with pulse-respiration ratio than pulse rate. Respiration is negatively correlated with autonomic parameters. And the slower respiration, the higher parasympathetic index in low pulse-respiration ratio group.

• 대한물리치료과학회지
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• 제18권3호
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• pp.53-61
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• 2011

Purpose : his study was to analyze the reliability and validity on Oswestry Low Back Pain Disability Index (OLBPDI) in patients with low back pain. Methods : The sample consisted of 211 patients who had received treatments at the physical therapy units of 3 medical institutions from February to December 2008 in Andong city. Questionnaires on the OLBPDI were recruited by 6 physical therapists. The internal structure and reliability of the scales were evaluated by means of item-internal consistency(Cronbach's alpha coefficient:${\alpha}$), item-discriminant validity, Pearson's relation coefficient. Results : An average of patients's age was 41.1 years. The range of OLBPDI subscales were .93~.94 in Cronbach's ${\alpha}$. The internal consistency reliability of total item-each item were also internally consistent with Cronbach's ${\alpha}$ range of .94~.95(Pearson's correlation coefficient range: .62~.89). However, high correlation were obtained among 10 items(.67~.83), therefore the item-discriminant validity was a little low. Conclusion: In conclusion, the results reported here confirm the reliability of the OLBPDI scales in patients with low back pain. The collection of information on the level of disability due to low back pain using this instrument was acceptable to patients. A further prospective multi-center study will be necessary to prove the reliability and validity.

• 산업기술연구
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• 제28권B호
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• pp.81-89
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• 2008

This paper is results of investigating the dominant factors influencing to coefficient of consolidation in horizontal direction of Korean marine clays and their correlations through literature review. From the results of analyzing data obtained from field tests such as piezocone penetration and dilatometer tests as well as laboratory tests, coefficient of consolidation in the horizontal direction was found to increase with increase of stiffness index of soil while it decreases with the increase of dissipation time of pore pressure developed during field tests. In general, the coefficient of consolidation in the horizontal direction tends to increase with increase of undrained shear strength and preconsolidation pressure although correlation between them are relatively low. Friction ratio has a high correlation with coefficient of consolidation in the horizontal direction in case of friction ratio being greater than 1.0. For methods of estimating coefficient of consolidation in the horizontal direction with different testing device, values obtained from methods of P2-logt and DMT-A with dilatometer were quite similar to values from piezocone penetration test. Consistency of soil is quite proportional to coefficient of consolidation in the horizontal direction. Clear correlation between coefficients of consolidation in the horizontal and the vertical directions could not be found. coefficient of consolidation in the horizontal direction estimated from the results of field test tends to be 1.13~3.11 times greater than that obtained from laboratory tests.

• 정보처리학회논문지B
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• 제17B권1호
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• pp.9-14
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• 2010

본 논문에서는 다중 센서를 선택하는 냄새 인식 시스템에서 최적의 센서 조합을 선택하기 위하여 통계적 분석 기반의 센서 사이의 상관계수를 이용하는 방법을 제안한다. 제안하는 센서 결정 방법은 금속 산화물 반도체(Metal Oxide Semiconductor : MOS) 센서 어레이를 사용하여 냄새 데이터를 획득한 후 획득한 냄새의 상관도를 기반으로 적합한 센서를 결정한다. 우선 측정 대상이 유사한 MOS 가스센서 중 응답의 크기가 작고 변화가 낮은 센서를 제외하여 총 16개의 센서를 선별한다. 입력되는 냄새로부터 16개의 센서를 사용하여 냄새 DB를 구축하고 각 센서별 상관계수를 계산한 후 상관도가 낮은 센서를 선택한다. 선택된 센서는 유사한 응답 특성을 갖는 센서를 제거한 것이며 제안한 방법으로 최적의 센서를 결정 할 수 있다. 제안된 센서 결정 방법의 성능 평가를 위해 꽃 냄새 인식 시스템에 적용하였다. 상관계수를 이용한 꽃 냄새 인식 시스템에 제안한 방법을 적용한 결과로 16개의 센서를 사용할 경우 95.67%의 인식률을 보이는 반면 제안한 센서 결정 방법을 적용한 꽃 냄새 인식 시스템은 6개를 사용한 경우 94.67%, 8개의 센서를 사용한 경우 96%의 인식률을 도출하는 것을 확인하였다.