• Journal of the Korean Statistical Society
• /
• v.36 no.1
• /
• pp.77-91
• /
• 2007

This paper considers development of noninformative priors for the familial data when the families have equal number of offspring. Several noninformative priors including the widely used Jeffreys' prior as well as the different reference priors are derived. Also, a simultaneously-marginally-probability-matching prior is considered and probability matching priors are derived when the parameter of interest is inter- or intra-class correlation coefficient. The simulation study implemented by Gibbs sampler shows that two-group reference prior is slightly edge over the others in terms of coverage probability.

• Journal of Environmental Health Sciences
• /
• v.47 no.1
• /
• pp.64-77
• /
• 2021

Objective: Biological monitoring of trace elements in human blood samples has become an important indicator of the health environment. The purpose of this study was to detect and evaluate multiple metal items in blood samples based on ICP-MS, to perform comparative evaluation with the existing analysis method, and to develop and verify a new method. Methods: 100 μL of whole blood from 80 healthy subjects was used to analyze ten metals (Sb, tAs, Cd, Pb, Mn, Hg, Mo, Ni, Se, Tl) using ICP-MS. Verification of the analysis method included calculation of linearity, accuracy, precision and detection limits. In addition, a comparative test with the conventional graphite furnace atomic absorption spectroscopy (GF-AAS) method was performed. In the case of Pb, Cd, and Hg in whole blood, cross-analysis between Pb, Cd, and Hg analysis methods was performed to confirm the difference between the existing method and the new method (ICP-MS). Results: The coefficient of determination (R2) was 0.999 or higher in seven items and 0.995 or higher in three items. The Pb result showed that Pearson's correlation coefficient was very high at 0.983, and the intraclass correlation coefficient was 0.966. The Cd result showed that Pearson's correlation coefficient was 0.917 between the existing method and the new analysis concentration value. Its intraclass correlation coefficient was 0.960, and there was no significant difference between the two groups. Hg had a low correlation at 0.687, and the intraclass correlation coefficient was 0.761, which was lower than that of Pb and Cd. The intra-day and inter-day accuracy of Pd and Cd were satisfactory, but Hg did not meet the criteria for both accuracy and precision when compared with the conventional analysis method. Conclusion: This study can be meaningful in that it proposes a more efficient and feasible analysis method by verifying a blood heavy metal concentration experiment using multiple simultaneous analyses. All samples were processed and analyzed using the new ICP-MS. It was confirmed that the agreement between the two methods was very high, with the agreement between the current and new methods being 0.769 to 0.998. This study proposes an efficient simultaneous methodology capable of analyzing multiple elements with small samples. In the future, studies of various applications and the reliability of ICP-MS analysis methods are required, and research on the verification of accurate, precise, and continuous analysis methods is required.

• Journal of the Korean Data and Information Science Society
• /
• v.15 no.4
• /
• pp.743-752
• /
• 2004

In this paper, we develop the Bayesian model selection procedure using the reference prior for comparing two nested model such as the independent and intraclass models using the distance or divergence between the two as the basis of comparison. A suitable criterion for this is the power divergence measure as introduced by Cressie and Read(1984). Such a measure includes the Kullback -Liebler divergence measures and the Hellinger divergence measure as special cases. For this problem, the power divergence measure turns out to be a function solely of $\rho$, the intraclass correlation coefficient. Also, this function is convex, and the minimum is attained at $\rho=0$. We use reference prior for $\rho$. Due to the duality between hypothesis tests and set estimation, the hypothesis testing problem can also be solved by solving a corresponding set estimation problem. The present paper develops Bayesian method based on the Kullback-Liebler and Hellinger divergence measures, rejecting $H_0:\rho=0$ when the specified divergence measure exceeds some number d. This number d is so chosen that the resulting credible interval for the divergence measure has specified coverage probability $1-{\alpha}$. The length of such an interval is compared with the equal two-tailed credible interval and the HPD credible interval for $\rho$ with the same coverage probability which can also be inverted into acceptance regions of $H_0:\rho=0$. Example is considered where the HPD interval based on the one-at- a-time reference prior turns out to be the shortest credible interval having the same coverage probability.

• The Korean Journal of Applied Statistics
• /
• v.27 no.1
• /
• pp.89-102
• /
• 2014

In this study, we analyze the effect on the smoking status in the Seoul Metropolitan area using a multilevel logistic model with Community Health Survey data from the Korea Centers for Disease Control and Prevention. Intraclass correlation coefficient (ICC), profiling analysis and two types of predicted value were used to determine the appropriate multilevel analysis level. Sensitivity, specificity, percentage of correctly classified observations (PCC) and ROC curve evaluated model performance. We showed the applicability for multilevel analysis allowed for the possibility that different factors contribute to within group and between group variability using survey data.

• Journal of Korean Physical Therapy Science
• /
• v.8 no.1
• /
• pp.917-921
• /
• 2001

The purpose of this study was to examine the difference in measurements of passive range of motion(PROM) of shoulder when motions are assessed in sitting, as compared with supine and the intratester and intertester reliabilities for goniometric measurements of shoulder PROM using two different sizes of goniometers. * A thesis submitted to the committee of Graduate School of Public Health, Chungnam National University in partial fulfillment of the requirements for the degree of Master of Public Health conferred in February 2001. Fifty one adult male subjects were measured three times, in random order, for the six shoulder motions(flexion, extension, abduction, adduction, external rotation, and internal rotation) while sitting and supine by three different therapists. Data were analyzed to determine intraclass correlation coefficients (ICCs) and paired "t" values between trials for measurements with different goniometer and betweensitting and supine trials. There was statistical difference in measurement of shoulder motion between supine and sitting position and no statistical difference in goniometric type. The intratester intraclass correlation coefficients (ICCs) for all motions ranged from .87 to .98. The ICCs for the intertester reliability of PROM measurements of all shoulder motion ranged from .26 to .89. These findings suggest that reliable measures of PROM of the shoulder can be obtained using standard goniometry in a proper position.

• The Korean Journal of Applied Statistics
• /
• v.32 no.1
• /
• pp.15-27
• /
• 2019

The reliability of the data means the overall consistency of the measurement results. Methods for evaluating reliability have been continuously studied because it affects the results of the statistical analysis. Cronbach's ${\alpha}$ coefficient or intraclass correlation coefficient is used for reliability evaluation; however, these measures cannot be applied to data consisting of three-dimensional coordinates to represent an object. In this study, we propose a measure to evaluate the reliability of three dimensional shapes based on statistical shape analysis that is made possible by extracting the shape information from the measured three dimensional coordinates and decomposing the shape variation.

• Korean Journal of Applied Biomechanics
• /
• v.12 no.2
• /
• pp.245-257
• /
• 2002

The purpose of this study was to develop a simple, valid, and reliable instrument for measuring forward flexion of trunk-hip joint. The subject included 44 females for sports major of volunteers at D. Women's University. In establishing the validity, objectivity the reliability of the new flexibility test(NF-test) for trunk-hip joint, Takei- flexometer(modified Leighton flexometer) was administered as the reference instrument, and test-retest method was utilized with the best scores. Intraclass correlation coefficient was obtained to use two way-mixed effect model and this value was average measure. The Pearson product correlation coefficient of L in this study were; the new flexibility test and Takei-flexometer as the reference tool correlated r = .962 in the first test, r = .960 in the second test. The intraclass correlation coefficient of the new flexibility test between in the initial test and in the retest were R = .994 for L, R =.993 for Y, and the intraclass correlation coefficient of the new flexibility test between L and Y were R =.985 in the initial test, and R =.986 in the retest. Based on the above findings, the following conclusions are presented. It was found the new flexibility test (NF test) was a valid, reliable, objective tool for measuring forward flexion of trunk-hip joint, and possible to be recommended as he test for measuring trunk-hip flexibility in the field.

• Journal of Oriental Neuropsychiatry
• /
• v.25 no.4
• /
• pp.351-358
• /
• 2014

Objectives: This study was performed to evaluate the reliability and validity of the instrument of oriental medical evaluation for Hwa-byung. Methods: 97 participants diagnosed with Hwa-byung divided into 5 pattern identifications by the instrument on pattern identifications for Hwa-byung were tested by the instrument of oriental medical evaluation for Hwa-byung twice a week. Results: The intraclass correlation coefficient of the test-retest analysis of oriental medical evaluation for Hwa-byung had over moderate agreement. The intraclass correlation coefficient of test-retest analysis of evaluation index of symptoms had moderate agreement for the total symptoms, and fair agreement for the physical and mental symptoms. The validity analysis of the instrument represented a positive correlation in the pattern identification of stagnation of liver Gi, malfunction of gallbladder due to phlegm stagnation, and disharmony between heart and kidneys. Conclusions: The results showed that the reliability analysis of the instrument of oriental medical evaluation for Hwa-byung showed over moderate agreement, and validity analysis represented a positive correlation except for the pattern identification of flare-up of liver fire and deficiency of both Gi and blood.

• Physical Therapy Rehabilitation Science
• /
• v.7 no.2
• /
• pp.61-66
• /
• 2018

Objective: Patellofemoral pain syndrome (PFPS) is a condition that is characterized by patellar discomfort or pain that is aggravated during certain activities such as ascending/descending stairs. The Patellofemoral Disability Index (PDI) was developed to assess the effect of pain on functional activities in individuals with PFPS. The objectives of the current study were to determine the internal consistency, test-retest reliability, and validity of this index. Design: Cross-sectional study. Methods: Forty-one subjects who had PFPS with a mean age of $28.8{\pm}5.0years$ and a mean body mass index of $25.6{\pm}4.7kg/m^2$ participated in the study. All subjects were concurrently enrolled in a clinical trial for which they were instructed to complete hamstring-resistance exercises for 4 weeks. Over the course of the intervention, they completed both the PDI and the Oswestry Disability Index (ODI) at baseline after two weeks, and after four weeks. Pearson correlation coefficient was used to assess the criterion validity. Cronbach's ${\alpha}$ was used to examine the internal consistency. Intraclass correlation coefficients with 95% confidence interval were computed to examine test-retest reliability. Results: Subjects' responses within both the PDI and the ODI yielded Pearson correlation coefficient values that were positive and highly significant (range, 0.73-0.97; p<0.001). There was a high level of internal consistency (Cronbach's ${\alpha}{\geq}0.8$), with the exception of stair climbing (Cronbach's ${\alpha}=0.65$). Intraclass correlation ranged from 0.87 to 0.92, indicating high levels of test-retest reliability. Conclusions: The PDI is a valid, reliable, and feasible method of assessing pain and functional ability in patients with PFPS.

• International Journal of Internet, Broadcasting and Communication
• /
• v.10 no.3
• /
• pp.65-72
• /
• 2018

The purpose of this study was to assess the intra-tester and inter-tester reliability and validity of elbow flexion range of motion using a smart phone used by the general public. Thirty-one general people participated in this study. The range of motion in active elbow flexion was measured with a goniometer and smart phone over two times by two observers. The intra-taster and inter-tester reliability were evaluated using the intraclass correlation coefficient(ICC). The validity was measured by Pearson's correlation coefficient. The intra-observer reliability was good in all measured items ICC>0.900. The inter-observer reliability was high with ICC>0.806. All correlation coefficients of android app and goniometer were greater than 0.868 and showed a significant positive correlation (p<0.01). The range of motion measurement with a smart phone showed acceptable reliability. Therefore, using a smartphone to measure the range of motion of the elbow joint could provide convenience and economic benefits.