• The Korean Journal of Applied Statistics
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• v.22 no.6
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• pp.1167-1176
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• 2009

Few studies have investigated the quantitative relationship between port ownership structure and port efficiency with mixed results. This paper therefore contributes to the empirical literature by investigating the impact of port privatization on port efficiency using sample data drawn from the world's major ports. Moreover, this study applies the Bayesian approach to estimate the impact of port ownership on port efficiency. We fit Bayesian stochastic frontier model which is introduced by Griffin and Steel (2007) by WinBUGS. World's 25 main ports data are used for analysis. Based on MCMC sampling, we estimate parameters of the model and efficiency index of each ports. Moreover, we add estimates from package Frontier 4.1c in order to compare them with Bayesian results.

• The Korean Journal of Applied Statistics
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• v.26 no.3
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• pp.453-470
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• 2013

In this paper, we consider a Bayesian analysis of the dose-effect relationship of cadmium to evaluate a benchmark dose(BMD). For this purpose, two dose-response curves commonly used in the toxicity study are fitted based on Bayesian methods to the data collected from the scientific literature on cadmium toxicity. Specifically, Bayesian meta-analysis and hierarchical modeling build an overall dose-effect relationship that use a piecewise linear model and Hill model, where the inter-study heterogeneity and inter-individual variability of dose and effect such as gender, age and ethnicity are accounted. Estimation of the unknown parameters is made by using a Markov chain Monte Carlo algorithm based user-friendly software WinBUGS. Benchmark dose estimates are evaluated for various cut-offs and compared with different tested subpopulations with with gender, age and ethnicity based on these two Bayesian hierarchical models.

• Communications for Statistical Applications and Methods
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• v.21 no.2
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• pp.135-145
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• 2014

The present study surveys Bayesian modeling structure for inferences about transition probabilities of Markov chain. The motivation of the study came from the data that shows transitional behaviors of emotionally disturbed children undergoing residential treatment program. Dirichlet distribution was used as prior for the multinomial distribution. The analysis with real data was implemented in WinBUGS programming environment. The performance of the model was compared to that of alternative approaches.

• Journal of Acupuncture Research
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• v.24 no.4
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• pp.13-23
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• 2007

Objectives : The aim of the present study was to assess the effects of Sa-am acupuncture (Damjeonggyeok) on autonomic nervous system in night nurses by heart rate variability. Methods : Five night nurses were divided into two groups. We checked their HRV once after sleeping for night and 5 times after working for night, 4 times after operation. We operate Sa-am acupuncture (Damjeonggyeok) and sham acupuncture twice by turns for group A and in reverse order for group B. We checked responses of HRV change after operations. Statistical analysis was performed by using the SPSS Win. Ver. 13.0 for analysis about correlation between data, and Baysian analysis using WinBUGS(Ver. 1.4) for comparison between Sa-am acupuncture (Damjeonggyeok) and sham acupuncture. Results : The median overall decrease for difference in responses of low-frequency power in normalized units (LF (NU)) was -16.56 (-28.88, -6.446), the median overall increase for difference in responses to high-frequency power in normalized units (HF (NU)) was 16.25 (8.104, 28.6) and for the median overall decrease for difference in responses to the ratio of low- to high-frequency power (LF/HF) was -1.846 (-3.922, -0.069), 95% credibility intervals being shown in brackets. VAS of stress was correlated with LF (NU) and HF (NU), LF/HF (p<0.0l). Conclusion : Sa-am acupuncture (Damjeonggyeok) might have sympatholytic and parasympathomimetic effects.

• Proceedings of the Korean Association for Survey Research Conference
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• 2006.06a
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• pp.131-159
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• 2006

This paper consider multinomial group testing which is concerned with classification each of N given units into one of k disjoint categories. In this paper, we propose exact Bayesian, approximate Bayesian, bootstrap methods for estimating individual category proportions using the multinomial group testing model proposed by Bar-Lev et al (2005). By the comparison of Mcan Squre Error (MSE), it is shown that the exact Bayesian method has a bettor efficiency and consistency than maximum likelihood method. We suggest an approximate Bayesian approach using Markov Chain Monte Carlo (MCMC) for posterior computation. We derive exact credible intervals based on the exact Bayesian estimators and present confidence intervals using the bootstrap and MCMC. These intervals arc shown to often have better coverage properties and similar mean lengths to maximum likelihood method already available. Furthermore the proposed models are illustrated using data from a HIV blooding test study throughout California, 2000.

• Journal of Acupuncture Research
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• v.25 no.3
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• pp.1-17
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• 2008

Objectives : This study was designed to evaluate the effect of moving cupping therapy on the edema of paretic hand in stroke patients. Methods : The subjects were stroke patients with flaccid hemiplegia. Each subject's routine therapy program was maintained throughout single subject ABAB design. During the first week, baseline data were gathered. During the second and fourth week, intervention was provided(total 20minutes of moving cupping therapy, from contralateral to ipsilateral, distal to proximal). During third and fifth week, data were gathered with treatment withdrawn. Edema was measured with hand volumeter and measuring tape. Basically Bayesian analysis was performed using WinBUGS(ver. 1.4), for addition, visual graph and mean score were also presented for comparison between treatment(moving cupping therapy) and non-treatment. Results : The visual graph and mean score showed decrease in edema during the treatment weeks. Overall decrease in edema by moving cupping therapy was verified significantly by using Bayesian ana-lysis(95% credibility intervals). Conclusions : This study suggests that moving cupping therapy could be applicable for reducing post-stroke hand edema. Further research would be needed to establish guidelines for use.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4839-4842
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• 2014

Background: Although the Cox's proportional hazard model is the popular approach for survival analysis to investigate significant risk factors of cancer patient survival, it is not appropriate in the case of log-term disease free survival. Recently, cure rate models have been introduced to distinguish between clinical determinants of cure and variables associated with the time to event of interest. The aim of this study was to use a cure rate model to determine the clinical associated factors for cure rates of patients with breast cancer (BC). Materials and Methods: This prospective cohort study covered 305 patients with BC, admitted at Shahid Faiazbakhsh Hospital, Tehran, during 2006 to 2008 and followed until April 2012. Cases of patient death were confirmed by telephone contact. For data analysis, a non-mixed cure rate model with Poisson distribution and negative binomial distribution were employed. All analyses were carried out using a developed Macro in WinBugs. Deviance information criteria (DIC) were employed to find the best model. Results: The overall 1-year, 3-year and 5-year relative survival rates were 97%, 89% and 74%. Metastasis and stage of BC were the significant factors, but age was significant only in negative binomial model. The DIC also showed that the negative binomial model had a better fit. Conclusions: This study indicated that, metastasis and stage of BC were identified as the clinical criteria for cure rates. There are limited studies on BC survival which employed these cure rate models to identify the clinical factors associated with cure. These models are better than Cox, in the case of long-term survival.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.231-239
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• 2015

A Poisson model is the first choice for counts data. Quasi Poisson or negative binomial models are usually used in cases of over (or under) dispersed data. However, these models might be unsuitable if the data consist of excessive number of zeros (zero inflated data). For zero inflated counts data, Zero Inflated Poisson (ZIP) or Zero Inflated Negative Binomial (ZINB) models are recommended to address the issue. In this paper, we further considered a situation where zero inflated data are spatially correlated. A mixed effect model with random effects that account for spatial autocorrelation is used to fit the data.

• Korean Journal of Acupuncture
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• v.25 no.2
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• pp.125-141
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• 2008

Objective : The aim of this study is to investigate the curative effect of Bee Venom Acupuncture Therapy for pain and limited R.O.M (range of motion) of shoulder in stroke patients. Methods : The subjects of this study were 6 patients with shoulder pain in stroke sequelae. Routine Oriental Medical programs (Acupunture, moxibustion, herbal medicine and physical therapy) were maintained for each subject throughout this study. Single subject ABABAB design was adopted. Each period was 4 days as a rule. Only during the treatment period, Bee Venom Acupuncture Therapy was provided as intervention at the acupoints of LI15(Gyeonu),　TE14(Gyeollyo), GB21(Gyeonjeong), LI14(Bino). The change of pain was measured with a Visual Analogue Scale(VAS). The pain threshold was measured using pressure algometer at the same acupoints where Bee Venom Acupuncture Therapy was provided. And the R.O.M of shoulder joint (flexion, extension, abduction, adduction, external rotation, internal rotation) was measured as well. Analysis was performed by Bayesian analysis using WinBUGS for the comparison of treatment(Bee Venom Acupuncture Therapy) and non-treatment. Results : The median overall improvement for difference in VAS was -2.219(-3.213, -1.175), for difference in external rotation of shoulder R.O.M was 9.992(-2.298, 18.49), for difference in tenderness score of LI14(Bino) by pressure algometer was 5.05(0.6283, 7.762). 95% credibility intervals being shown in brackets. However, the median overall improvement for difference in the other measurements was not significant. Conclusion : This study suggests that Bee Venom Therapy may be applicable to decrease pain and improve R.O.M of shoulder in hemiplegia patients with stroke. Further elaborated single subject designs need to be accumulated to confirm the effects of Bee Venom Acupunture Therapy on shoulder pain in patients with stroke sequelae.

• Journal of Acupuncture Research
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• v.30 no.3
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• pp.39-49
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• 2013

Objectives : The purpose of this study is to assess the effect of Taegeuk acupuncture on reducing mental stress by analyzing heart rate variability in Soeumin. Methods : Six Soeumin-diagnosed men participated in this study. They were randomly divided into group A and group B. Each participant went through 4 sessions every week with 1 week of washout period in between each session. HRV was measured three times at every session; at baseline, after administering mentally stressful circumstances and after applying Soeumin Taegeuk acupuncture or Soyangin Taegeuk acupuncture. This study was designed as a crossover clinical trial. Group A participants were treated with two sets of Soeumin Taegeuk and Soyangin Taegeuk acupuncture treatment in respective order (i.e. Soeumin Taegeuk - Soyangin Taegeuk - Soeumin Taegeuk - Soyangin Taegeuk acupuncture treatment). Group B participants were treated with reverse-ordered acupuncture treatment (i.e. Soyangin Taegeuk - Soeumin Taegeuk - Soyangin Taegeuk - Soeumin Taegeuk acupuncture treatment ). Bayesian analysis was performed by using WinBUGS(Ver. 1.4.3) for comparison between Soeumin Taegeuk acupuncture and Soyangin Taegeuk acupuncture. Results : Overall, Soeumin Taegeuk acupuncture tends to reduce LF/HF ratio, LF, HF, LF(Norm) and increase HF(Norm) more than Soyangin Taegeuk acupuncture, but the difference was not statistically significant. In one participant, however, Soeumin Taegeuk acupuncture reduced LF/HF ratio, LF(Norm) and increased HF(Norm) more than Soyangin Taegeuk acupuncture, and the difference was stastatistically significant. Conclusions : This study suggests that Soeumin Taegeuk acupuncture might be an effective means of stabilizing mental stress-induced imbalance of autonomic nervous system for Soeumin.