• Title/Summary/Keyword: linear correlation coefficient

검색결과 768건 처리시간 0.031초

상관성 분석을 통한 침입수 발생 영향인자 분석 (Factor analysis on infiltration using correlations)

  • 류재나;오재일;최익훈
    • 상하수도학회지
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    • 제25권2호
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    • pp.185-192
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    • 2011
  • Pearson's correlation was used to determine relations between infiltration and affecting factors using flow monitoring data measured in 24 areas with different characteristics. Factors showed relatively high correlations than others were indexed to determine infiltration rates of the study area. Among 8 factors(service area, sewer length, sewer diameter, multiplier of sewer length and diameter, number of manholes, population, number of properties, number of households) tested, the multiplier of sewer length and diameter, the number of population and the number of household in each service area indicated higher correlation coefficient(>0.8) than others. The goodness of fitness of linear regressions between infiltration and the factors followed the order: sewer length and diameter(0.68)> population(0.65)> number of household(0.60). Infiltration rates calculated by the multiplier of sewer length and diameter, the number of population and the number of household in each service area were 0.046~1.0396 $m^{3}/d{\cdot}mm-km$, 0.0917~1.7355 $m^{3}/capita{\cdot}d$, 0.196~4.529 $m^{3}/household {\cdot}d$ respectively. After sewerage rehabilitation work of the area, the infiltration rates calculated by above factors with high correlations are expected to be used for comparing effectiveness of the work once they are estimated under the same flow measuring conditions.

근골격계 만성통증 환자의 통증신념과 통증정도, 대처양상 및 통증생활방해정도와의 관계 (Relationships among the Pain Belief, Pain Coping, and Pain Disability of Patients with Chronic Musculoskeletal Pain)

  • 최성남;김정화
    • 재활간호학회지
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    • 제15권1호
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    • pp.30-38
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    • 2012
  • Purpose: The purpose of this study was to understand the degree of pain belief in musculoskeletal patients, and to identify the correlation with chronic pain, pain coping and pain disability. Methods: A total of 203 inpatients or outpatients with chronic pain in orthopedics agreed voluntarily to participate in this study and answer a questionnaire. Data were analyzed using SPSS/WIN 17.0 program with descriptive statistics, t-test, ANOVA, Scheffe test, Pearson's correlation coefficient, and simple linear regression. Results: The degree of pain belief in this study showed statistically significant differences depending on their age, education, job, health status, and pain duration. Among the variables correlating with pain belief in this study, there were positive correlations between pain and pain disability, pain and passive coping, pain belief and passive coping, pain belief and pain, pain belief and pain disability. The strongest correlation was passive coping and pain disability. Conclusion: From the results of this study, we concluded that it is necessary to develop the nursing intervention which can help reducing negative pain belief in patients with chronic musculoskeletal pain. Also we need to enhance the ways of coping to active or chronic pains for controlling them effectively.

섬유 근접센서를 이용한 복약 여부 평가에 관한 연구 (A Study of Medication Adherence Using Textile Proximity Sensor)

  • 호종갑;왕창원;민세동
    • 전기학회논문지
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    • 제65권7호
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    • pp.1257-1262
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    • 2016
  • The purpose of this study is to evaluate whether to take a medicine based on a measuring data using textile proximity sensor. We developed a proximity sensor of ring type using conductive textile, and acquired a data in accordance with the quantity of each pills. To evaluate our approach, we designed an experimental protocol that is counting pills subtracting the one which contains range of 0 T(Tablet, 4,100mg) from 20 T. And, The experiments were performed a nine times in the same way. In order to remove a noise and smoothen data, data preprocessing were performed using resampling method and moving average filter which has ten points. Then, we calculated a linear trend line equation, and analyzed a correlation between pill quantity and trend line equation. As a results, correlation coefficient was shown at 0.833 through using a Spearman's correlation method and we could be determined that data was continuos decreases when take a medicine.

Relationship of Phenolic Compounds and Free-radical Scavenging Activity in Black and Red Rice Extract

  • Hu, Gao-Sheng;Xu, Kai-Xiu;Jeong, Soon Jae;Kim, Doh-Hoon
    • 한국육종학회지
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    • 제42권2호
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    • pp.129-138
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    • 2010
  • Total phenolic content, total anthocyanin content and antioxidant activity were analyzed from rice samples collected in Korea, Japan and China. The results showed that the total phenolic content and free-radical scavenging activity differed significantly in these rice lines. The correlation between content and activity was subsequently investigated. The results showed that in black rice, anthocyanin was the major phenolic component and that both phenolic content and anthocyanin content were closely correlated with free-radical scavenging activity. Reverse Phase High Performance Liquid Chromatography (RP-HPLC) data showed that cyanidin-3-O-glucoside and peonidin-3-O-glucoside composed about 90% of the total anthocyanin content in black rice and in red rice. In the red rice extract, the total phenolic content produced a high correlation coefficient with antioxidant activity but correlated very poorly with the total anthocyanin content. The $OD_{458}$ and the $OD_{500}$ values which represent the proanthocyanidin content of the rice extract, produced high correlation coefficients with antioxidant activity and total phenolic content. These results suggest that the $OD_{458}$ and the $OD_{500}$ values can be used to evaluate the quality of red rice. In addition, based on the data obtained, a competitive accumulation model of anthocyanin and proanthocyanidin in black and red rice was proposed.

Research on Security Threats for SMEs by Workplace in the COVID-19 Environment

  • Kim, Woo-Su;Lim, Heon-Wook
    • International Journal of Advanced Culture Technology
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    • 제10권2호
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    • pp.307-313
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    • 2022
  • Although telecommuting of SMEs has been activated due to the COVID-19 phenomenon, the security model for this is insufficient. Accordingly, the study was divided into threats centered on smartphones and threats centered on smartphone users. As a result of the study, one-third of SMEs are working from home. At this company with 100 employees, more than 50% of them work from home.and In the metal, machinery and chemical industries with factories, 20% of them work from home. As a result of analyzing the correlation between telecommuting according to the presence or absence of a factory, the correlation coefficient (r=-.385) has a clear linear relationship. And, as a result of the regression analysis, the R-squared value was 0.148, so companies with factories are highly related to telecommuting. In other words, we found that SMEs with factories do not want to work from home. In addition, as a result of analyzing the level of security threats, there were great concerns about theft, hacking, and phone taking during remote work. As limitations of the study, there were difficulties in selecting SMEs from the population in a non-face-to-face work environment, and there were limitations in the questionnaire items for deriving a non-face-to-face work environment.

Artificial neural network model using ultrasonic test results to predict compressive stress in concrete

  • Ongpeng, Jason;Soberano, Marcus;Oreta, Andres;Hirose, Sohichi
    • Computers and Concrete
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    • 제19권1호
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    • pp.59-68
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    • 2017
  • This study focused on modeling the behavior of the compressive stress using the average strain and ultrasonic test results in concrete. Feed-forward backpropagation artificial neural network (ANN) models were used to compare four types of concrete mixtures with varying water cement ratio (WC), ordinary concrete (ORC) and concrete with short steel fiber-reinforcement (FRC). Sixteen (16) $150mm{\times}150mm{\times}150mm$ concrete cubes were used; each contained eighteen (18) data sets. Ultrasonic test with pitch-catch configuration was conducted at each loading state to record linear and nonlinear test response with multiple step loads. Statistical Spearman's rank correlation was used to reduce the input parameters. Different types of concrete produced similar top five input parameters that had high correlation to compressive stress: average strain (${\varepsilon}$), fundamental harmonic amplitude (A1), $2^{nd}$ harmonic amplitude (A2), $3^{rd}$ harmonic amplitude (A3), and peak to peak amplitude (PPA). Twenty-eight ANN models were trained, validated and tested. A model was chosen for each WC with the highest Pearson correlation coefficient (R) in testing, and the soundness of the behavior for the input parameters in relation to the compressive stress. The ANN model showed increasing WC produced delayed response to stress at initial stages, abruptly responding after 40%. This was due to the presence of more voids for high water cement ratio that activated Contact Acoustic Nonlinearity (CAN) at the latter stage of the loading path. FRC showed slow response to stress than ORC, indicating the resistance of short steel fiber that delayed stress increase against the loading path.

A Pilot Study on Hip Bone Mineral Densities Estimation from Forearm CBCT images

  • Ko, Hoon;Lee, Chang-Hoon;Jeong, Kwanmoon;Lee, Myeung Su;Nam, Yunyoung;Yoon, Kwon-Ha;Lee, Jinseok
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권12호
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    • pp.6054-6068
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    • 2017
  • In this paper, we defined the relative cross-sectional area of forearm cortical bone and investigated its correlation with hip bone mineral density values of total femur, femoral neck, femoral trochanter, femoral inter-trochanter and femoral ward's triangle, respectively. Based on the correlations, we established a linear transformation between the relative cross-sectional area of forearm cortical bone and each hip bone BMD. We obtained forearm images using CBCT and hip bone BMDs using dual-energy X-ray absorptiometry (DXA) for 28 subjects. We also investigated the optimal forearm region to provide the strongest correlation coefficient. We used the optimized forearm region to establish each linear transformation to estimate BMD values for total femur, femoral neck, femoral trochanter, femoral inter-trochanter and femoral ward's triangle from the relative cross-sectional area of forearm cortical bone, respectively. We observed the strong correlations with total femur (r=0.889), femoral neck (r=0.924), femoral trochanter (r=0.821), femoral inter-trochanter (r=0.867) and femoral ward's triangle (r=0.895), respectively. The strongest correlation was observed in the forearm mid-shaft regions. Our results suggest that the hip bone BMD values can be simply estimated from forearm CBCT images in a convenient sitting position without X-ray exposure on a hip including genital organs, and may be useful for screening osteoporosis.

MODIS 자료를 이용한 한반도에서의 가강수량 장기변화 분석 (Long-term variability of Total PrecipitableWater using a MODIS over Korea)

  • 권채영;이다래;이경상;서민지;성노훈;최성원;진동현;김홍희;한경수
    • 대한원격탐사학회지
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    • 제32권2호
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    • pp.195-200
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    • 2016
  • 수증기는 다양한 규모의 대기 순환을 유도하고 온실효과의 약 60%를 설명하는 중요한 기후 변수이다 (Karl and Trenberth, 2003). 본 연구의 목적은 Terra/Aqua 위성의 Moderate Resolution Imaging Spectroradiometer (MODIS) 센서를 통해 생산된 총 가강수량 (Total Precipitable Water, TPW) 자료의 장기적인 변화를 분석하고 강수 및 기온 실측자료와의 비교를 통해 TPW의 변화가 한반도를 포함한 동아시아 지역의 기후에 미치는 영향을 정량적으로 파악하고자 하는 것이다. 따라서 본 연구에서는 TPW와 강수 및 기온과의 상관을 알아보기 위하여 선형회귀분석을 실시하였고 TPW와 강수 및 기온의 주기 변화 양상을 분석하기 위하여 조화분석을 실시하였다. 선형회귀분석 결과 TPW와 강수 및 기온과의 상관성이 높게 나타났다(TPW-기온의 결정계수 (determination coefficient, $R^2$): 0.94, TPW아노말리-기온 아노말리의 결정계수: 0.8, TPW-강수량의 결정계수: 0.73, TPW아노말리-강수량 아노말리의 결정계수: 0.69). 조화분석 결과 2년에서 5년 사이의 다년주기 성분 중에서 TPW와 강수량 모두 3.5년 주기성분에서 진폭의 기여도가 높게 나타났으며 TPW와 강수량의 3.5년 주기 성분의 위상이 유사한 시기에 나타났다.

안벽 앞에 설치된 진동수주형 파력발전장치의 반사율과 추출효율과의 상관관계 (Correlation of Reflection Coefficient and Extracted Efficiency of an Oscillating Water Column Device in Front of a Seawall)

  • 조일형;김정록
    • 한국해안·해양공학회논문집
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    • 제32권4호
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    • pp.242-251
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    • 2020
  • 본 연구에서는 직립 안벽 앞에 설치된 2차원 진동수주형 파력발전장치의 추출효율과 반사율을 규칙파와 불규칙파에 대하여 살펴보고 둘 사이의 상관관계를 조사하였다. 해석이론으로 선형포텐셜 이론에 기반을 둔 고유함수전개법을 사용하였다. 공기실이 완전 개방되었을 때 입사파에 의한 산란문제와 공기실이 닫혀 있을 때 공기실내의 변동압력에 의한 파의 방사문제를 풀어 공기실 내부의 유량을 구하고, 이를 공기실내의 공기 흐름에 대한 연속방정식에 대입하여 변동압력을 구한다. 추출파워가 최대가 되는 최적 터빈계수를 적용하여 진동수주형 파력발전장치의 최대 추출효율과 반사율을 규칙파와 불규칙파에 대하여 구하였다. 파랑에너지를 효율적으로 흡수하도록 설계된 진동수주형 파력발전장치는 동시에 반사파를 줄이는데 기여하였다.

The Correlation between the Degree of Enophthalmos and the Extent of Fracture in Medial Orbital Wall Fracture Left Untreated for Over Six Months: A Retrospective Analysis of 81 Cases at a Single Institution

  • Sung, Yun Sik;Chung, Chan Min;Hong, In Pyo
    • Archives of Plastic Surgery
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    • 제40권4호
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    • pp.335-340
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    • 2013
  • Background In patients with medial orbital wall fracture, predicting the correlation between the degree of enophthalmos and the extent of fracture is essential for deciding on surgical treatment. We conducted this retrospective study to identify the correlation between the two parameters. Methods We quantitatively analyzed the correlation between the area of the bone defect and the degree of enophthalmos on computed tomography scans in 81 patients with medial orbital wall fracture who had been left untreated for more than six months. Results There was a significant linear positive correlation between the area of the medial orbital wall fracture and the degree of enophthalmos with a formula of E=0.705A+0.061 (E, the degree of enophthalmos; A, the area of bone defect) (Pearson's correlation coefficient, 0.812) (P<0.05). In addition, that there were no cases in which the degree of enophthalmos was greater than 2 mm when the area of the medial orbital wall fracture was smaller than $1.90cm^2$. Conclusions Our results indicate not only that 2 mm of enophthalmos corresponds to a bone defect area of approximately $2.75cm^2$ in patients with medial orbital wall fracture but also that the degree of enophthalmos could be quantitatively predicted based on the area of the bone defect even more than six months after trauma.