• The Korean Journal of Applied Statistics
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• v.16 no.2
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• pp.377-393
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• 2003

Several confidence interval estimates for the difference of two binomial proportions were introduced. Bootstrap confidence interval is also suggested. We examined the over estimation property of approximate intervals and under estimation trend of exact intervals for the difference of proportions. We compared these confidence intervals based on the average coverage probability, expected width and skewness measure. Particularly actual coverage probability were calculated by using the prior distribution of parameters. Monte Carlo simulation for small sample size is conducted. Some interesting contour plots of average coverage probability and marginal plots for several interval estimates are presented.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.5948-5971
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• 2019

Estimating loss rates with the packet traces captured from some point in the middle of the network has received much attention within the research community. Meanwhile, existing intermediate-point methods like [1] require the capturing system to capture all the TCP traffic that crosses the border of an access network (typically Gigabit network) destined to or coming from the Internet. However, limited to the performance of current hardware and software, capturing network traffic in a Gigabit environment is still a challenging task. The uncaptured packets will affect the total number of captured packets and the estimated number of packet losses, which eventually affects the accuracy of the estimated loss rate. Therefore, to obtain more accurate loss rate, a method of strengthening packet loss measurement from the network intermediate point is proposed in this paper. Through constructing a series of heuristic rules and leveraging the binomial distribution principle, the proposed method realizes the compensation for the estimated loss rate. Also, experiment results show that although there is no increase in the proportion of accurate estimates, the compensation makes the majority of estimates closer to the accurate ones.

• Journal of the Korean Data and Information Science Society
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• v.23 no.1
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• pp.53-61
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• 2012

There are cases when the sample size is determined based not only on the significance level but also on on the power or type II error. In this paper, we implemented the sample size and the power calculation when both the significance level and power for testing means in normal distributions and proportions in binomial distributions. The implementation is available on a web site. Alternately, we also calculate the power for a given effect size, type I error probability and sample size.

• Journal of agricultural medicine and community health
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• v.14 no.1
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• pp.44-53
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• 1989

The distribution pattern of Clonorchis sinensis metacercaria in Pseudorasvora parva population and correlation between P. parva and metacercaria of C. sinensis were studied. The surveved areas were Chomanpo and Bulamdong, Kim-Hae Gun which were endemic area of clonorchiasis, and wansa, Sa-Chon Gun, Souh Kyong-Sang Do. The results are as follows: 1) The areas of Chornanpo and Wansa showed high infectivity in 99-100% of infection rate and 282-308 of average infection number per-fish. But the area of Bulamdong showed relatively. low infectivity in 95.8% of infection rate and 44 of average infection number. 2) The distribution patterns of C. sinensis metacercaria in P. parva population which were collected in Chomanpo and Wansa were shown Poisson distribution and the distribution pattern in Bulamdong showed mid-pattern of shifting over from Poisson distribution to Negative binomial distribution. 3) The correlation between P. parva length and average number of C. sinensis metacercaria in the present studied areas represented as direct proportion relationship.

• The Korean Journal of Applied Statistics
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• v.19 no.1
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• pp.171-181
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• 2006

The Wald confidence interval has been considered as a standard method for the difference of proportions. However, the erratic behavior of the coverage probability of the Wald confidence interval is recognized in various literatures. Various alternatives have been proposed. Among them, Agresti-Caffo confidence interval has gained the reputation because of its simplicity and fairly good performance in terms of coverage probability. It is known however, that the Agresti-Caffo confidence interval is conservative. In this note, a confidence interval is developed using the weighted Polya posterior which was employed to obtain a confidence interval for the binomial proportion in Lee(2005). The resulting confidence interval is simple and effective in various respects such as the closeness of the average coverage probability to the nominal confidence level, the average expected length and the mean absolute error of the coverage probability. Practically it can be used for the interval estimation of the difference of proportions for any sample sizes and parameter values.

• Korea Trade Review
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• v.44 no.2
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• pp.109-126
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• 2019

Import refusals can be considered a new method of non-tariff barriers. This study aims to analyze reputation spillover effects on fish and fishery products imported from ASEAN countries to the U.S. FDA. The supply of aquatic products is not stable due to various factors such as reduction of fish stocks and climate change. Fish is a basic food ingested directly, but there are many ways to control the safety of aquatic products. ASEAN countries account for about 20% of U.S.imports in fish and fishery products. For Southeast Asian countries, fish and fishery products comprise a high proportion of exports revenue. Despite the large share of exports to the U.S., Southeast Asia countries have been receiving many import refusals from the United States. In this study, a theoretical model for examining import refusals is suggested using the negative binomial counting process. The reputation spillover effect, was divided into two spillover effects of 'neighbor reputation' and 'sector reputation'. Results show that there exists a neighbor reputation spillover effect. It can be said if there was a import refusal of the same product from neighboring countries in the preceding year, the home country have a possibility to experience import refusals of the same product. Therefore, it is interpreted that neighboring countries have good standard compliance can help home countries to effectively reach the target markets. Our findings have a important policy implication for ASEAN exporters of fish and fishery products.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.84-92
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• 2019

The deterioration of the urban heat environment due to climate change and the occurrence of heat-related diseases have emerged as one of the major social problems. This has led to more research on climate change, including heat waves, but it is mainly focused on climate factors. However, the urban heat island phenomenon accelerates the summer heat wave, and the increasing trend of heat-related patients in urban areas suggests the impact of the city's environment. Thus, this study analyzed the effects of physical and social characteristics of urban areas on heat-related patients in Seoul and Gyeonggi-do. The analysis showed that the ratio of the total area of residential, commercial and industrial facilities, the main source of heat energy locality, among the land use statuses, was not statistically significant, but the road area and the green area were found to have a positive and negative The population density and the percentage of people aged 65 or older, the percentage of people living alone and the proportion of people receiving basic living were all shown to be significant, with only the ratio of elderly living alone and the ratio of population density having negative effects. The results of the study can be used to develop urban policy alternatives related to local warming patients.

• Journal of Korean Society of Transportation
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• v.30 no.6
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• pp.37-46
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• 2012

The number of traffic accidents caused by elderly drivers over the age of 65 has surged over the past ten years from 37,000 to 274,000 cases. The proportion of elderly drivers' accidents has jumped 3.1 times from 1.2% to 3.7% out of all traffic accidents, and traffic safety organizations are pursuing diverse measures to address the situation. Above all, connecting safety measures with an in-depth research on behavioral and physical characteristics of elderly drivers will prove vital. This study conducted an empirical research linking the driving characteristics and traffic accidents by elderly drivers based on the Driving Aptitude Test items and traffic accident data, which enabled the measurement of behavioral characteristics of elderly drivers. In developing the Influence Model, we applied the zero-inflated Poisson (ZIP) regression model and selected an accident prediction model based on the Bayesian Influence in regards to the ZIP regression model and the zero-inflated negative binomial (ZINB) regression model. According to the results of the AAE analysis, the ZIP regression model was more appropriate and it was found that three variables? prediction of velocity, diversion, and cognitive ability? had a relation of influence with traffic accidents caused by elderly drivers.

• Journal of The Korean Society of Emergency Medicine
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• v.29 no.5
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• pp.423-429
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• 2018

Objective: Falling is a common cause of head injury in preschool aged children. We investigated the characteristics of mild head injuries caused by falling and the association between body weight and occurrence of traumatic brain injuries (TBI). Methods: This retrospective observational study was conducted on head-injured preschool-aged children that visited the emergency department from January 2012 to December 2015. Characteristics such as age, sex, weight, free fall height, floor type, and presence of TBI, as defined as cerebral hemorrhage or skull fracture, were investigated. We calculated body weight percentiles by calibrating age and weight and categorized them into four quartile ranges. We grouped all included cases into two groups according to the presence of TBI. The characteristics of the two groups were compared by using chi-square test, and the association with TBI was investigated by using binomial logistic regression. Results: A total of 701 children were included, and TBI was observed in 95 children. Children with TBI were younger. The proportion of children with TBI was higher in the third and fourth quartiles of the body weight group as well as according to soft floor and fall from high height (${\geq}1m$). The odds of soft floor being associated with TBI was higher than the odds for hard floor (odds ratio, 2.734; 95% confidence interval [CI], 1.597-4.680). The odds of high height (${\geq}1m$) being associated with TBI was higher than that for low height (odds ratio, 2.306; 95% CI, 1.155-4.601), and the odds ratio for the weight percentile group was 1.228 (95% CI, 1.005-1.499). Conclusion: Prevalence of TBI after falling in preschool-aged children might be associated with high fall-height and body weight quartiles.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1143-1153
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• 1998

Background : Recent outbreaks of pulmonary disease due to drug-resistant strains of Mycobacterium Tuberculosis have resulted in significant morbidity and mortality in patients worldwide. We reviewed our experience to evaluate the effects of pulmonary resection on the management of multidrug-resistant tuberculosis. Method : A retrospective review was performed of 41 patients undergoing pulmonary resection for multidrug-resistant tuberculosis between January 1993 and December 1997. We divided these into 3 groups according to the radiologic findings : (1) patients who have reasonably localized lesion (Localized Lesion Group ; LLG) (2) patients who have cavitary lesions after pulmonary resection on chest roentgenogram (Remained Cavity Group : RCG) (3) patients who have Remained infiltrative lesions postoperatively (Remained infiltrative group : RIG). We evaluated the negative conversion rate after resection and overall response rate of the groups. Then they were compared with the results of the chemotherapy on the multi drug-resistant tuberculosis which has been outcome by Goble et al. Goble et al reported that negative conversion rate was 65% and overall response rate, 56% over a mean period of 5.1 months. Results : Seventy five point six percent were men and 24.4% women with a median age of 31 years (range, 16 to 60 years). Although the patients were treated preoperatively with multidrug regimens in an effort to reduce the mycobacterial burden, 22 of 41 were still sputum culture positive at the time of surgery. 20 of 22 patients(90.9%, p<0.01) responded which is defined as negative sputum cultures within 2 months postoperative. Of 26 patients with the sufficient follow up data, 19 have Remained sputum culture negative for a mean duration of 25.7 months (73.1%, p<0.05). The bulk of the disease was manifest in one lung, but lesser amounts of contralateral disease were demonstrated in 15, consisted of 8 in RIG and 7 in RCG, of 41. 12 of 12 patients (100%, p<0.01) who were sputum positive at the time of surgery in LLG converted successfully. 14 of 15 patients (93.3%, p<0.05) with the follow up have completed treatment and not relapsed for a mean period of 25. 7 months. The mean length of postoperative drug therapy of LLG was 12.2 months. In RIG, postoperative negative conversion rate was 83.3% which was not significant statistically. There was a statistical significance in overall response rate (100%, p<0.05) of RIG for a mean period of 24.4 months with a mean length of postoperative chemotherapy, 11.8 months. In RCG a statistically lower overall response rate (14.3%, p<0.01) has been revealed for a mean duration of follow up, 24.2 months. A negative conversion rate of RCG was 75% which was not significant statistically. Conclusion : Surgery plays an important role in the management of patients with multidrug-resistant Mycobacterium tuberculosis infection. Aggressive pulmonary resection should be performed for resistant Mycobacterium tuberculosis infection to avoid treatment failure or relapse. Especially all cavitary lesions on preoperative chest roentgenogram should be resected completely. If all of them could not be resected perfectly, you should not open the thorax.