• Title/Summary/Keyword: Pearson correlation

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Correlation analysis of traffic and crack in concrete lining (교통량과 콘크리트 라이닝 균열 상관관계 분석)

  • Gyu-Phil Lee
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.25 no.5
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    • pp.345-355
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    • 2023
  • An analysis of covariance and Pearson correlation coefficient were performed to identify the relationship between both variables: traffic volume and crack. For this, it was carried out to analyse 216 tunnel inspection/diagnosis results with respect to the traffic. As a result, it has been proven that traffic volume and cracks in concrete linings are highly correlated. Therefore, it is recommended to consider traffic volume in planning of preemptive maintenance such as crack repair, etc.

Estimation of the Exhaust Characteristics of Biodiesel Used in Diesel Engine (디젤엔진에서 바이오디젤의 배기가스 특성 평가)

  • Baek, Seok Heum;Yoon, Jeong Hwan;Jung, Woo Sung;Ha, Hyeong Soo;Chung, Sung Sik;Yeom, Jeong Kuk
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.2
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    • pp.129-137
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    • 2014
  • In this study, the characteristics of exhaust gas as a function of the biodiesel mixing ratio were investigated. Diesel and waste oil were used for preparing mixed fuel, and the ratios of the mixed fuel were varied in the BD3~BD100 range. The injection pressures(${\Delta}p_{inj}$) was considered as an experimental variable and was set to 400 bar, 600 bar, 800 bar, 1000 bar, and 1200 bar. Furthermore, for quantitatively analyzing the characteristics of exhaust gas(NOx and Soot), the concepts of Pearson correlation coefficient and Spearman rank-order correlation coefficient based on statistics were introduced. Consequently, it was found that the correlation of the emission of NOx and Soot is linear, and the Pearson and Spearman coefficients are -0.732 and -0.724, respectively, under all analysis conditions. Especially, for the injection pressure of 800 bar, a simultaneous reduction in NOx and Soot emission is possible by controlling the biodiesel mixing ratio. This is because the correlation coefficients of NOx and Soot emissions were nearly 0, as the Pearson correlation coefficient was -0.089.

Correlation between Instrument on Pattern Identification for Depression and Psychological Tests by Statistical Analysis (통계적 분석을 통한 우울증 변증도구와 심리검사의 상관성 연구)

  • Kim, Hwan;Lee, Hun-Soo;Lee, Eun Jung;Park, Joon-Ho;Kang, Wee-Chang;Jung, In Chul
    • Journal of Oriental Neuropsychiatry
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    • v.27 no.3
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    • pp.131-146
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    • 2016
  • Objectives: This study was performed to determine the correlation between Instrument on Pattern Identification for Depression and Psychological tests by Pearson Correlation Coefficient and Regression analysis.Methods: Two assessors carried out the evaluation using the instrument on pattern identification for depression. They also performed the following psychological tests: Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), State-Trait Anger Expression Inventory (STAXI), the Temperament and Character Inventory (TCI), Insomnia Severity Index (ISI_Total), Self-disclosure Inventory, subjective well-being Inventory, Health perception Inventory, and Personality Assessment Inventory (PAI). A total of 167 participants who got HAM-D score over 12 were targeted for the evaluation. Our research team carried out Pearson correlation coefficient analyses and regression analysis between pattern identification for depression and Psychological tests. We listed the results by descending order and interpreted the results.Results: Pearson correlation analysis revealed the following results: 1) Stagnation of Liver Gi was associated with BDI (0.60) and STAI (0.55); 2) Dual Deficiency of the Heart and Spleen was associated with BDI (0.60), ISI_Total (0.52), and STAI (0.42); 3) Relieving stagnation of Phlegm-Gi was associated with BDI (0.65), STAI (0.54), and Subjective well-being inventory (−0.52); 4) Gi-deficiency Mingled with sputum was associated with BDI (0.50), ISI_Total (0.40), and STAI (0.395); 5) Stagnant Gi transforming into fire was associated with BDI (0.56), STAI_TR (0.51), and Health perception Inventory (−0.458); 6) Yin-Deficiency with Effulgent Fire was associated with BDI (0.55), ISI_total (0.54), and STAI (0.41).Conclusions: Through correlation analysis between Instrument on Pattern Identification for Depression and Psychological tests, we could suggest a System for Oriental Medical Diagnosis for Depression.

Determination of effective parameters on surface settlement during shield TBM

  • Kim, Dongku;Pham, Khanh;Park, Sangyeong;Oh, Ju-Young;Choi, Hangseok
    • Geomechanics and Engineering
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    • v.21 no.2
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    • pp.153-164
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    • 2020
  • Tunnel excavation in shallow soft ground conditions of urban areas experiences inevitable surface settlements that threaten the stability of nearby infrastructures. Surface settlements during shield TBM tunneling are related to a number of factors including geotechnical conditions, tunnel geometry and excavation methods. In this paper, a database collected from a construction section of Hong Kong subway was used to analyze the correlation of settlement-inducing factors and surface settlements monitored at different locations of a transverse trough. The Pearson correlation analysis result revealed a correlation between the factors in consideration. Factors such as the face pressure, advance speed, thrust force, cutter torque, twin tunnel distance and ground water level presented a modest correlation with the surface settlement, while no significant trends between the other factors and the surface settlements were observed. It can be concluded that an integrated effect of the settlement-inducing factors should be related to the magnitude of surface settlements.

Interpersonal Relationship and the Influencing Factors in Nursing Students (간호대학생의 대인관계 및 관련요인)

  • Lee, Mi-Ryon;Nam, Mun-Hee
    • Journal of Digital Convergence
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    • v.12 no.6
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    • pp.509-517
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    • 2014
  • The objective of this study was to investigate the degree of interpersonal relationship in nursing students according to their characteristics. This descriptive correlation study conducted visit-surveys with organized questionnaires and sampled 306 nursing students. Data was analyzed by t-tests, ANOVA, Pearson's correlation coefficients and multiple regression analysis using SPSS/WIN 14.0. Findings revealed that; 1) the degree of interpersonal relationship in nursing students according to their characteristics were significantly different in age and grade; 2) Pearson's correlation revealed a significant association among interpersonal relationship, family function and self-differentiation; 3) multiple regression analysis showed self-differentiation and family function significantly influenced interpersonal relationship in nursing students. Based on the findings of this study, nursing professionals should provide proper program of interpersonal relationship related to self-differentiation and family function.

Development and Validation of Computerized Semiquantitative Food Frequency Questionnaire for Koreans with High-Risk of Hypercholesterolemia

  • Kim, Hyung-Sook;Lee, Kyoungsin;Park, Haymie
    • Journal of Community Nutrition
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    • v.6 no.1
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    • pp.35-41
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    • 2004
  • Cardiovascular disease has the highest mortality rate in South Korea. Previous studies have reported that serum cholesterol level relates to intake of dietary fat and cholesterol. Therefore, in this study we developed a semiquantitative food frequency questionnaire (FFQ) for Koreans with a high-risk of hypercholesterolemia and to validate the FFQ. Semiquantitative FFQ, which includes 160 food items, reflects intakes of energy, fat, saturated fatty acid (SFA), monounsaturated fatty acid (MUPA), polyunsaturated fatty acid (PUPA) and cholesterol. We chose food items from the previous study of our research group (Suh 1999) which reported a nutritional status of Korean adults with normocholesterolemia, borderline and hypercholesterolemia. To validate the FFQ, we compared the results of the FFQ with those of a 3-day food record using a paired t-test. In addition, we calculated Pearson's and Spearmen's correlation coefficients. Intakes assessed by the FFQ and a 3-day food record were classified into quartile and the degree of agreement was obtained. Fifty-five participants responded for the validation study by completing both the FFQ and a 3-day food record. Pearson's correlation coefficients between estimated intakes by respective methods for energy, fat, SF A, MUPA, PUPA and cholesterol were 0.32,0.41,0.37,0.41,0.37 and 0.21, respectively. Spearman's correlation coefficients of energy, fat, SF A, MUPA, PUPA, cholesterol were 0.31, 0.44, 0.39, 0.46, 0.46, and 0.37, respectively. Nutrient densities in 1000kcal were compared. Pearson's correlation coefficient of cholesterol density increased and other values were similar with original values. The average degree of agreement was 67% that intakes of energy, fat, SF A, MUPA, PUPA and cholesterol assessed by the FFQ and 3-day food records were classified within the same and the adjacent quartile. On the average, 8% were misclassified into the extreme opposite quartile. The average of weighted kappa was 0.46. In conclusion, the FFQ developed in this study is considered to be a reliable tool to assess nutrient intakes for Koreans with a risk of hypercholesterolemia because the FFQ reflects the intakes of energy, fat, SFA, MUFA, PUPA, and cholesterol.

Mapping Poverty Distribution of Urban Area using VIIRS Nighttime Light Satellite Imageries in D.I Yogyakarta, Indonesia

  • KHAIRUNNISAH;Arie Wahyu WIJAYANTO;Setia, PRAMANA
    • Asian Journal of Business Environment
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    • v.13 no.2
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    • pp.9-20
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    • 2023
  • Purpose: This study aims to map the spatial distribution of poverty using nighttime light satellite images as a proxy indicator of economic activities and infrastructure distribution in D.I Yogyakarta, Indonesia. Research design, data, and methodology: This study uses official poverty statistics (National Socio-economic Survey (SUSENAS) and Poverty Database 2015) to compare satellite imagery's ability to identify poor urban areas in D.I Yogyakarta. National Socioeconomic Survey (SUSENAS), as poverty statistics at the macro level, uses expenditure to determine the poor in a region. Poverty Database 2015 (BDT 2015), as poverty statistics at the micro-level, uses asset ownership to determine the poor population in an area. Pearson correlation is used to identify the correlation among variables and construct a Support Vector Regression (SVR) model to estimate the poverty level at a granular level of 1 km x 1 km. Results: It is found that macro poverty level and moderate annual nighttime light intensity have a Pearson correlation of 74 percent. It is more significant than micro poverty, with the Pearson correlation being 49 percent in 2015. The SVR prediction model can achieve the root mean squared error (RMSE) of up to 8.48 percent on SUSENAS 2020 poverty data.Conclusion: Nighttime light satellite imagery data has potential benefits as alternative data to support regional poverty mapping, especially in urban areas. Using satellite imagery data is better at predicting regional poverty based on expenditure than asset ownership at the micro-level. Light intensity at night can better describe the use of electricity consumption for economic activities at night, which is captured in spending on electricity financing compared to asset ownership.

The Study of Emission Characteristics of Biodiesel Fuel in Diesel Engines

  • Yeom, Jeong-Kuk
    • Journal of Power System Engineering
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    • v.19 no.1
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    • pp.56-63
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    • 2015
  • In this study, the exhaust characteristics of the diesel engine for the change of the mixing ratio of biodiesel fuel were quantitatively analyzed by using the numerical analysis method. As the fuel used in the experiment, the diesel and biodiesel(waste oil, soybean oil), the mixed fuel BD2(Diesel only), BD3, BD5, BD20, BD50 and BD100 were used. The injection pressure($p_{inj}$) was set to 400bar, 600bar, 800bar, 1000bar and 1200bar as the experimental variable. Also the concept of the standard deviation, Pearson's correlation coefficient and Spearman rank-order correlation coefficient based on the statistics was introduced in order to analyze the exhaust characteristics of the quantitative NOx and Soot according to the injection pressure and the mixing ratio variation of biodiesel blending fuel. It is considered that as a result of studies, for the waste oil, NOx and Soot can be simultaneously reduced through control of the mixing ratio at the regions of $p_{inj}=400bar$ and $p_{inj}=600bar$, and the Soot can be reduced without affecting on the emission of NOx at more than $p_{inj}=800bar$. For the soybean oil, NOx and Soot can be simultaneously reduced at $p_{inj}=400bar$ and the Soot can be reduced without affecting on the emission of NOx at $p_{inj}=600bar$.

Job Stress, Burnout, Nursing Organizational Culture and Turnover Intention among Nurses (간호사의 직무스트레스, 소진, 간호조직문화 및 이직의도)

  • Yeun, Young-Ran
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.4981-4986
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    • 2014
  • The aim of this study was to identify how job stress, burnout and nursing organizational culture affect the turnover intention of nurses. The participants were 198 nurses from two general hospitals. The data was analyzed using descriptive statistics, Pearson correlation analysis, and stepwise multiple regression using the SPSS/PC 18.0 program. The turnover intention had a positive correlation with job stress (r=.59, p<.001), burnout (r=.64, p<.001), and a negative correlation with the nursing organizational culture (r= -34, p<.001). The predictors of the turnover intention were job demand, insufficient job control, interpersonal conflict, emotional exhaustion, and depersonalization. The results of the study can be used to develop a program for reducing nurses' turnover intention.

Reliability and Validity of the Korean Western Ontario and McMaster Universities(WOMAC) Osteoarthritis Index in Patients with Osteoarthritis of the Knee (퇴행성 슬관절염 환자에 대한 한글판 WOMAC Index의 신뢰도와 타당성에 관한 연구)

  • Ko, Tae-Sung;Kim, Seong-Yeol;Lee, Jong-Soo
    • Journal of Korean Medicine Rehabilitation
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    • v.19 no.2
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    • pp.251-260
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    • 2009
  • Objectives : To investigate reliability and validity of Korean translation of Western Ontario and McMaster Universities(WOMAC) osteoarthritis index. Methods : The reliablity, construct validity of the Korean WOMAC Index in the patient of knee osteoarthritis was investigated. Test-retest reliability was quantified with pearson's correlation coefficient and intraclass correlation coefficient. Internal consistency was quantified with Cronbach's ${\alpha}$. and construct validity with pearson's correlation coefficient by correlating of the Visual Analog Scale(VAS). Results : Test-retest reliability of Korean WOMAC Index for pain was 0.76 to 0.95, stiffness was 0.89 to 0.94, and physical function was 0.71 to 0.95. Intraclass correlation coefficient for pain was 0.76 to 0.94, stiffness was 0.54 to 0.89, and physical function was 0.70 to 0.95. Internal consistency were 0.94 and 0.94 for the first and second time, respectively. Construct validity for pain was 0.79, for stiffness was 0.66, and physical function was 0.67. Conclusions : The Korean translation of Western Ontario and McMaster Universities(WOMAC) osteoarthritis index is reliable, valid assessment tool in knee osteoarthritis.