• Journal of the Korean Data and Information Science Society
• /
• v.22 no.6
• /
• pp.1241-1250
• /
• 2011

In this paper, we develop noninformative priors for the log-normal distributions when the parameter of interest is the common mean. We developed Jeffreys' prior, th reference priors and the first order matching priors. It turns out that the reference prior and Jeffreys' prior do not satisfy a first order matching criterion, and Jeffreys' pri the reference prior and the first order matching prior are different. Some simulation study is performed and a real example is given.

• Journal of the Korean Data and Information Science Society
• /
• v.23 no.3
• /
• pp.605-616
• /
• 2012

This article deals with the problem of testing on the common mean of several normal populations. We propose Bayesian hypothesis testing procedures for the common normal mean under the noninformative prior. The noninformative prior is usually improper and yields a calibration problem that makes the Bayes factor to be defined u to a multiplicative constant. So we propose the default Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. Simulation study and an example are provided.

• Communications for Statistical Applications and Methods
• /
• v.1 no.1
• /
• pp.57-74
• /
• 1994

This paper deals with the estimation problems of a common mean of several independent normal populations with unknown variances, based on random samples of equal size. The authors suggest a promising approach and a new estimator to improve Graybill-Deal estimator further. By Monte Carlo simulation study, the efficiency of new estimator is compared with that of Graybill-Deal estimator.

• Journal of the Korean Data and Information Science Society
• /
• v.15 no.1
• /
• pp.59-74
• /
• 2004

The paper considers the Bayesian interval estimation for the common mean of several normal populations. A Bayesian procedure is proposed based on the idea of matching asymptotically the coverage probabilities of Bayesian credible intervals with their frequentist counterparts. Several frequentist procedures based on pivots and P-values are introduced and compared with Bayesian procedure through simulation study. Both simulation results demonstrate that the Bayesian procedure performs as well or better than any available frequentist procedure even from a frequentist perspective.

• The Korean Journal of Applied Statistics
• /
• v.3 no.2
• /
• pp.79-89
• /
• 1990

For selecting a subset of k normal populations containing the one with the largest mean, a Bayes-$P^*$ selection procedure is considered when the common variance is unknown. Performance of the Bayes-$P^*$ selection procedure is compared with a well known classical procedure through a simulation study. Some frequentist's characteristics of Bayes-$P^*$ procedure are also studied.

• Imaging Science in Dentistry
• /
• v.37 no.2
• /
• pp.79-82
• /
• 2007

Purpose: The purpose of this study was to investigate whether panoramic radiographs were useful in predicting osteoporosis. Materials and Methods: 50 postmenoposal women between the age of 41.8 and 78.5 were classified as normal and osteoporosis groups according to the bone mineral density of lumbar vertebrae. Panoramic radiographs were taken. Age, body mass index, remaining mandibular teeth, mandibular cortical thickness and morphology, and fractal dimensions at periapical areas of mandibular first molars were evaluated to differentiate the two groups. Results: The age of osteoporotic group was statistically significantly higher than that of normal group (p<0.05), but not the body mass index or number of remaining mandibular teeth. The mean fractal dimension of osteoporotic group was $1.391{\pm}0.085$, and was significantly lower than that of the normal group, which was $1.523{\pm}0.725$ (p<0.01). Thick mandibular cortical thickness was common in normal group, whereas thin or very thin mandibular cortical thickness was common in osteoporotic group and the difference was significant (p < 0.05). C2 pattern was common in normal group followed by C1, whereas C2 was common in osteoporotic group followed by C3. The difference was statistically significant (p< 0.0 1). Conclusion: Age, mandibular cortical thickness and shape, fractal dimension on panoramic radiographs were useful in predicting osteoporosis.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.9 no.1
• /
• pp.5-10
• /
• 1998

Voice rehabilitation is very important concerning in laryngectomees. Esophageal speech is a common and widely used method of voice restoration. But, until now there is no reliable data which shows the aerodynamic characteristics of esophageal speech. In order to evaluate the vocal quality of normal laryngeal and esophageal speech, several aerodynamic parameters were measured in 13 adults with normal laryngeal voice and 2 excellent esophageal speakers using Aerophone II voice function analyzer. The examined parameters were maximal flow rate, mean airflow rate, subglottic pressure, vocal efficiency, glottic resistance, maximal phonation time and mean sound pressure level. In vocal efficiency, there is no difference between two groups, but in other parameters, marked differences were showed in esophageal speakers, especially mean resistance. Results indicates that esophageal speakers make the efficient voices with poor aerodynamic condition, comparing with normal laryngeal speakers.

• Journal of the Korean Statistical Society
• /
• v.22 no.1
• /
• pp.71-81
• /
• 1993

Among k independent normal populations with unknown means and a common unknown variance, the problem of detecting the population with the largest absolute value of mean is considered. This problem is formulated in a manner close to the framework of testing hypotheses, and the maximum error probability and the minimum power are considered. The power charts necessary to determine the sample size are provided. The problem of detecting the population with the smallest absolute value of mean is also considered.

• The Journal of Pediatrics of Korean Medicine
• /
• v.21 no.2
• /
• pp.1-12
• /
• 2007

Objectives : Allergic children have known to have multiple behavior problems. Among them, attentional ability disorder is one of the most common problems. This study is to examine relationship between learning ability and allergic rhinitis by analyzing EEG status of children. Methods : We analyzed cognitive functions of two different children groups; 21 children with allergic rhinitis and 19 normal children with CANS 3000(Central & Autonomic Nervous System, LAXTHA Inc., Korea), cognitive functions assessment program by EEG. Results : 1. According to mean active EEG rhythm of Theta, Alpha, SMR, M-beta, there were no significant difference between allergic rhinitis and the normal group. 2. According to mean active EEG rhythm of right H-beta, Gamma wave allergic rhinitis group's value was significantly higher than that of the normal group. 3. According to mean cognitive strength, response, concentration, left / right brain activity and learning ability score, there were no significant difference between allergic rhinitis and the normal group. 4. According to mean workload score, allergic rhinitis group's value was significantly higher than that of the normal group. Conclusions : It is likely that allergic rhinitis group, which showed relatively high frequency EEG rhythm, is more fragile to stress and less active on mental processing. Along side with physical examination, psychological assessment should also be conjugated on treating children with allergic rhinitis.

• Women's Health Nursing
• /
• v.25 no.2
• /
• pp.207-218
• /
• 2019

Purpose: To compare reproductive health promoting behaviors (RHPBs) of infertile women with those of normal women and identify effects of RHPB on infertility. Methods: A total of 148 females (73 infertile women and 75 normal women) were enrolled in this study. Measurements included their general characteristics and RHPB using self-report questionnaires. Data were analyzed with descriptive statistics, ${\chi}^2$ test, ANCOVA, and hierarchical logistic regression using SPSS. Results: There were significant difference in incomes, number of family, number of term deliveries, and number of abortions according to infertility diagnosis. Mean duration of infertility was 32.16 months. Only 12.32% women had known cause of infertility. The most common cause of infertility was unknown. Mean RHPB score was 3.98 for infertile women and 4.41 for normal women. In logistic regression, total RHPB (odds ratio [OR], 0.21) and safe sex of RHPB (OR, 0.66) were significant factors influencing infertility. Infertile women's total RHPB and subcategories of RHPB (safe sex behavior and sexual transmitted disease [STD] prevention) were lower than those of normal women. Conclusion: For infertility women, RHPB-related intervention programs are needed, especially information about safe sex behavior and STD prevention.