• Title/Summary/Keyword: correlation coefficients

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Study on the Relationship between Health Risk Behaviors of Rural Residents by Regional Scale (지역 규모에 따른 농촌주민의 건강위험행동 관계 연구)

  • Seungyeon Cho
    • Journal of agricultural medicine and community health
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    • v.49 no.2
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    • pp.111-120
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    • 2024
  • Objective: This study aimed to analyze the correlation between factors affecting health risk behaviors of rural residents according to regional scale. Methods: Restricted-access data from the 2016~2021 Korea National Health and Nutrition Examination Survey and the multivariate probit model were used. As for health risk behaviors, smoking, drinking, lack of aerobic exercise, low level of healthy eating index, unvaccination, and non-participation in health examination were considered. Results: Controlling for individuals' socio-demographic characteristics, in general, correlation coefficients between unobservable factors affecting health risk behaviors were significant. However, the magnitude and statistical significance of the correlation coefficients varied by regional scale (dong/eup/myeon). This suggests that rural residents engage in health risk behaviors due to their different characteristics compared with urban dwellers, which also varies by whether residents are located in eup or myeon area. Conclusion: It is necessary to differentiate health care services between urban and rural areas in terms of type of service and programs based on the relationship between unobservable factors affecting each type of health risk behaviors.

Design of the LSF Parameter Quantizer for the Wideband Speech Codec (광대역 음성 부호화기용 선 스펙트럼 주파수 계수 양자화기 설계)

  • 지상현;강상원;윤병식
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.4
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    • pp.29-34
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    • 2001
  • In this paper, we designed an LSF coefficient quantizer of the wideband speech codec that can produce high quality speech service. For the efficient LSF coefficient quantizer, the interframe correlation was used. Also we separately quantized the LSF coefficients with high and low interframe correlation. Predictive pyramid vector quantizer (PVQ) was used for quantizing the LSF coefficients with high interframe correlation, and PVQ was used for quantizing the LSF coefficients with low interframe correlation. Experiments show that the proposed UF quantizer can quantize LSF information in 40 bits/frame, with an average spectral distortion (SD) of 1 dB and less than 3.87% frames having SD greater than 2 dB.

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Comparative Evaluation of Gravimetric Measurement Methods for Suspended Particles in Indoor and Outdoor Air (실내.외 공기 중 부유먼지 측정방법 상호간의 비교평가 - 중량법을 대상으로)

  • 백성옥;박지혜;서영교
    • Journal of Korean Society for Atmospheric Environment
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    • v.18 no.4
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    • pp.285-295
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    • 2002
  • In this study, several types of gravimetric methods (such as high, medium, low, and ultra low volume sampling methods) were applied to determine suspended particulate matter concentrations in both ambient and indoor environments. Comparative evaluations were undertaken with SPM data obtained using a variety of samplers (TSP, PM10, and PM4.0) at different sampling flow rates. Correlation coefficients between TSP and PM10 concentrations measured at different flow rates fell in the range of 0.73∼0.94 (n=40). In addition, correlation coefficients for PM concentrations measured by different TSP samplers were in the range of 0.90∼0.95 (n=36 or n=38), while 0.77∼0.91 (n=38) for PM10 samplers. Correlation analysis was also conducted on indoor monitoring data that were measured using ultra-low-volume samplers at both different or identical flow rates. The correlation coefficients were in the range of 0.98∼0.99 (n=38) between TSP and TSP and 0.92∼0.94 (n=38) between TSP and PM10. The mean ratio for high volume PM10 to TSP concentration that was monitored at identical flow rates in the ambient air appeared to be 0.72. The mean ratios of PM10 to TSP and PM4.0 to TSP observed with identical flow rates at indoor environments were 0.47 and 0.40. The results of this study may provide empirical information concerning the compatability of aerosol data obtained by gravimetric sampling methods at different flow rates.

Influence of Seedling Weight on Agronomic Characters and Their Relation with Bolting in Angelica gigas Nakai (참당귀 묘 중양별 생육특성과 추대와의 관계)

  • 안상득;유창연;조동하
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.39 no.5
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    • pp.426-430
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    • 1994
  • To establish the proper size of seedling of A. gigas, different weight of seedlings were used for this study. Agronomic characters including plant height, number of leaf, leaf length, number of inflorescence, fresh weight and rate of bolting of the aerial parts, root length, root diameter, number of lateral root and root weight of the underground parts were determined and correlation coefficients among them were estimated. Growth of A. gigas showed the significant vigor for all the characters of the aerial parts along with increasing of seedling weight, but root weight in yield decreased in proportion to increasing of seedling weight due to lignification of the root tissue. When the smaller seedlings were transplanted, bolting rates decreased to about 16% as compared with the traditional size of seedlings. Correlation coefficients between aerial and root characters in A. gigas were negative, and the characters such as plant height, number of leaf, number of inflorescence and fresh weight per plant showed highly significant correlation with the rate of bolting which is one of the characters having great influence on yield.

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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.

Response Spectrum Analysis of Floor Structure Subjected to Group Dynamic Loads (복수의 동적하중을 받는 바닥판 구조물의 응답스펙트럼 해석)

  • Kim, Tae-Ho;Han, Duck-Jeon
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.1
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    • pp.57-67
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    • 2008
  • In general, the response spectrum analysis(RSA) method is wifely used for seismic analysis of building structures, and the time history analysis(THA) is applied for computation of structural vibration caused by equipments, machines and moving loads, etc. However, compared with the RSA method, the THA method is very complex, difficult and time consuming. In this study, the maximum responses for the vertical vibration are calculated conveniently by the RSA method. At first, the process for the RSA in excitation is proposed, and the maximum modal responses are combined by CQC and SRSS methods. Also, the responses obtained by the two modal combination methods are compared to the responses by the THA. And the correlation coefficients for human activities is proposed, and the RSA responses obtained by used to the correlation coefficients are calculated. Finally, results of the proposed method are compared with those of the time history analysis and correlation coefficients should be considered for the RSA of floor structure subjected to group dynamic loads.

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Health-related Quality of Life Instrument With 8 Items for Use in Patients With Type 2 Diabetes Mellitus: A Validation Study in Korea

  • Kim, Juyoung;Lee, Hyeon-Jeong;Jo, Min-Woo
    • Journal of Preventive Medicine and Public Health
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    • v.55 no.3
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    • pp.234-242
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    • 2022
  • Objectives: This study assessed the validity and reliability of the Health-related Quality of Life Instrument with 8 Items (HINT-8) in patients with diabetes. HINT-8 is a newly-developed, generic health-related quality of life (HRQoL) instrument. Methods: Three HRQoL instruments-HINT-8, EuroQoL 5-Dimension 5-Level (EQ-5D-5L), and Short Form Health Survey version 2.0 (SF-36v2)-were provided to 300 patients with diabetes visiting a tertiary hospital for follow-up visits in Korea. The HRQoL scores obtained using the HINT-8 were evaluated for subgroups with known differences based on demographics and diabetes-related characteristics (known-group validity). The mean scores of the instruments were compared between groups segmented by their responses to the HINT-8 (discriminatory ability). Correlation coefficients of the HINT-8 with other instruments were calculated (convergent and divergent validity). The Cohen kappa and intra-class correlation coefficient (ICC) were also evaluated (test-retest reliability). Results: The average HINT-8 indexes were lower among women, older, and less-educated subjects. Subjects who did not list any problems on the HINT-8 had significantly higher HRQoL scores than those who did. The correlation coefficients of the HINT-8 with the EQ-5D-5L index and EuroQoL visual analogue scale were 0.715 (p<0.001) and 0.517 (p<0.001), respectively. The correlation coefficients between the HINT-8 index and the scores of 8 domains of the SF-36v2 ranged from 0.478 (p<0.001) to 0.669 (p<0.001). The Cohen kappa values for the HINT-8 ranged from 0.268 to 0.601, and the ICC of the HINT-8 index was 0.800 (95% confidence interval [CI], 0.720 to 0.860). Conclusions: This study showed that the HINT-8 is a valid and reliable HRQoL instrument for patients with diabetes.

Correlation of response spectral values in Japanese ground motions

  • Jayaram, Nirmal;Baker, Jack W.;Okano, Hajime;Ishida, Hiroshi;McCann, Martin W. Jr.;Mihara, Yoshinori
    • Earthquakes and Structures
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    • v.2 no.4
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    • pp.357-376
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    • 2011
  • Ground motion models predict the mean and standard deviation of the logarithm of spectral acceleration, as a function of predictor variables such as earthquake magnitude, distance and site condition. Such models have been developed for a variety of seismic environments throughout the world. Some calculations, such as the Conditional Mean Spectrum calculation, use this information but additionally require knowledge of correlation coefficients between logarithmic spectral acceleration values at multiple periods. Such correlation predictions have, to date, been developed primarily from data recorded in the Western United States from active shallow crustal earthquakes. This paper describes results from a study of spectral acceleration correlations from Japanese earthquake ground motion data that includes both crustal and subduction zone earthquakes. Comparisons are made between estimated correlations for Japanese response spectral ordinates and correlation estimates developed from Western United States ground motion data. The effect of ground motion model, earthquake source mechanism, seismic zone, site conditions, and source to site distance on estimated correlations is evaluated and discussed. Confidence intervals on these correlation estimates are introduced, to aid in identifying statistically significant differences in correlations among the factors considered. Observed general trends in correlation are similar to previous studies, with the exception of correlation of spectral accelerations between orthogonal components, which is seen to be higher here than previously observed. Some differences in correlations between earthquake source zones and earthquake mechanisms are observed, and so tables of correlations coefficients for each specific case are provided.

Correlation Among Items of Mechanical Tests in Raw Silk (생사기계검사 항목간의 상관관계)

  • 김영진;정지현;조동옥;이덕노
    • Journal of Sericultural and Entomological Science
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    • no.11
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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.

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Correlation Analysis of Aerodynamic Forces acting on Tall Buildings with Various Side Ratios (다양한 변장비를 가진 고층건축물에 작용하는 풍력의 상관 분석)

  • Kim, Wonsul;Yoshida, Akihito;Tamura, Yukio
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.2
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    • pp.153-160
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    • 2015
  • The objective of this study is to construct the TPU aerodynamic database with wind tunnel test data of overall wind loads and responses on tall buildings. In this study, wind tunnel tests were conducted to investigate characteristics of wind forces and the effect of wind load combination by cross-correlation analysis among along-wind overturning moment, across-wind overturning moment and torsional moment on a tall building with various side ratios(D/B=0.33, 0.50, 0.77, 0.83, 0.91, 1.0, 1.1, 1.2, 1.3, 2.0 and 3.0) for different terrain roughnesses. The results of wind tunnel tests were compared with those of past literatures. As a result, there was no significant effects of changing of terrain roughnesses on moment coefficients and power spectral densities of across-wind overturning moment coefficients and torsional moment coefficients with various side ratios. Further, these results were good agreement with those of past literatures. From cross-correlation analysis, the across-wind overturning moment coefficients were highly correlated with the torsional moment coefficients. The results of this study will be helpful for practical designers in preliminary design stage.