• The korean journal of orthodontics
• /
• v.31 no.2 s.85
• /
• pp.283-300
• /
• 2001

With socioeconomic development and change of esthetic recognition, the demand for orthodontic treatment and number of orthodontic patients has been increasing so rapidly. And frequency of malocclusion was changed. So this study was done in an attempt to provide an epidemiologic study so that we can accomodate their orthodontic needs adequately and to obtain the reliable quantitative information regarding the characteristics of orthodontic patients. Distribution and trends were examined in 3,070 malocclusion patients who had been examined and diagnosed at Department of Orthodontics, Dental Hospital, Chosun University over 10 year-period from 1990 to 1999. The results were as follows : 1. The number of patients per year was increasing trend and higher visiting rate in female(56.5%) than in male(43.5%). 2. Age distribution had shown 7${\sim}$ 12 year-old group being the largest(37.9%) and each percentage of 13${\sim}$18, 19${\sim}$24, above-19, 0${\sim}$6 year${\sim}$old group was 32.0%, 19.6%, 7.1%, 3.4%. 3. Hellman dental age IVa which is completion of the permanent dentition showed the highest percentage in male and female. 4. Geographic distribution showed a majority of patients in Kwang Ju(71.0%). Group within the distance 10km from Chosun Dental Hospital was 56.3% and group within 20km was 14.7%. 5. Anterior cross bite showed the highest percentage in chief complaints and percentage of Mn. prognathism and protrusion of Mx. teeth was 12.6%, 12.2%. 6. Distribution in the types of malocclusion according to the Angle's classification had shown; 38.9% for Class I, 20.7% for Class II division 1, 2.0% for Class III division 2, 38.4% for Class III. 7. In the dental vertical dysplasia according to the Angle's classification, deep bite was the most frequent in Class II div.1 and div. 2(24.3%, 56.7%) and open bite in Class III(21.4%). 8. In the skeletal sagittal dysplasia, 39.3% of skeletal Class II was due to the undergrowth of the mandible and 46.3% of skeletal Class III was due to the overgrowth of the mandible. 9. Distribution in orthodontic treatment acceding to the extraction and nonextraction had shown 66.9% for nonextraction case, 33.1% for extraction case, and four first bicuspids have been extracted in the highest percentage(38.6%). 10. Patients who had orthognathic surgery comprised 7.9%, with an increasing trend.

• The korean journal of orthodontics
• /
• v.22 no.3 s.38
• /
• pp.691-701
• /
• 1992

Over recent 20 years, with socioeconomic development and change of recognition of the population, more people are concerned about their health and appearance. To obtain the change of frequency of malocclusion and the demand for orthodontic treatment, with this trend, 2460 freshmen and students of Yonsei Univ. in 1991, aged from 18 to 21 were examined excluding 187 students who have history of orthodontic treatment, 86 students who are undergoing treatment, 39 students who have too much missing teeth to classify. After analize the frequency of malocclusion and the demand for orthodontic treatment, following results was obtained. 1. Sex ratio in the prevalence of malocclusion was $91.7\%/90.8\%$, male to female, so there was no sex predilection. 2. With regard to Angle's Classification, each percentage of Class I, Class II div. 1, Class II div. 2 and Class III was $61.6\%,\;11.3\%,\;1.9\%\;and\;16.7\%$. 3. Of Class I malocclusion, percentage of crowding was 53.2, this occupied the largest part of single findings and prevalent findings in combinations were also crowding - crossbite and crowding - Protrusion. 4. Of Class I malocclusion, over the portion of$95\%$, Bialveolar Protrusion have arised alone. 5. The distribution of Demands for orthodontic treatment of malocclusion were $41.3\%$ in males, and $51.3\%$ in females.

• Journal of Chest Surgery
• /
• v.27 no.9
• /
• pp.752-758
• /
• 1994

From July 1983 to December 1992, 145 patients with mitral valvular disease underwent open heart surgery at Chonbuk National University Hospital. Of these patients, 89 patients[61.4%] required mitral valve replacement. 56 patients [38.6 %] had mitral valve repair. There were 32 women and 24 men and the mean age was 34.3 years[range 6 years to 62 years].There were 23 cases of pure mitral stenosis, 19 cases of mitral regurgitation and 14 cases of mixedmitral valvular disease. The mean duration of symptom was 4.53 years and mean mitral valvularorifice diameter[in cases of pure stenosis and mixed mitral valvular lesion] was 0.96 cm. According to the NYHA classification, the distribution of patients preoperatively was as follows; class IIa, 15 patients; class lib, 17 patients; class III, 22 patients; class IV, 2 patients. Four patients[7%] had an embolic history preoperatively. 24 patients[ 43 %] were in atrial fibrillation. In cases of pure mitral stenosis, the technique used included open mitral commissurotomy[21atients], open mitral commissurotomy with mitral annuloplasty[2 patients]. In mixed mitral valvular disease, open mitral commissurotomy[ll patients] and open mitral commissurotomy with mitral annuloplasty[l patient] were performed. In cases of mitral regurgitation, mitral annuloplasty[5 patients], mitral valvuloplasty[6 patients], mitral annuloplasty with valvuloplasty [3 patients] and ring annuloplasty [5 patients] were performed.There was one perioperative death related to acute renal failure and sepsis. One late death was occurred related to heart failure after 10 months postoperatively. One patient required reoperation due to restenosis and no embolic episode was occured. After operation, 34 patients were in NYHA functional class I, 20 patients were in class IIa.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.7
• /
• pp.1008-1013
• /
• 2014

The use of antimicrobial agents for additives or therapeutics is strongly associated with a prevalence of antimicrobial resistance in commensal Enterobacteriaceae. We aimed to characterize integrons in Enterobacteriaceae isolates obtained from chicken cecums in Korea. Moreover, the correlation between integron gene cassettes and antimicrobial resistance was also investigated. A total of 90 isolates the belonged to Enterobacteriaceae were recovered from chickens grown at Gyeongsang and Chungcheong provinces in Korea. Antimicrobial susceptibility tests were performed by the disk diffusion method. PCR and DNA sequencing were also performed to characterize the gene cassette arrays of the integrons. Of the 90 Enterobacteriaceae isolates tested, 39 (43.3%) and 10 (11.1%) isolates carried class 1 and 2 integrons, respectively. Whereas the class 2 integron did not contain gene cassettes, the class 1 integrons carried seven different gene cassette arrays. The class 1 integrons harbored genes encoding resistant determinants to aminoglycosides (aadA1, aadA2, and aadA5), trimethoprim (dfrA1, dfrA12, dfrA17, and dfrA32), lincosamides (linF), and erythromycin (ereA). Moreover, the presence of a class 1 integron was significantly related to a high resistance rate of antimicrobial agents, such as spectinomycin and trimethoprim. We confirmed that diverse class 1 integrons were widely distributed in Enterobacteriaceae isolates from chickens and directly contributed to the resistance to diverse antimicrobial agents in Korea.

• Communications for Statistical Applications and Methods
• /
• v.28 no.6
• /
• pp.595-610
• /
• 2021

Recently a few articles have derived robust first-order rotatable and D-optimal designs for the lifetime response having distributions gamma, lognormal, Weibull, exponential assuming errors that are correlated with different correlation structures such as autocorrelated, intra-class, inter-class, tri-diagonal, compound symmetry. Practically, a first-order model is an adequate approximation to the true surface in a small region of the explanatory variables. A second-order model is always appropriate for an unknown region, or if there is any curvature in the system. The current article aims to extend the ideas of these articles for second-order models. Invariant (free of the above four distributions) robust (free of correlation parameter values) second-order rotatable designs have been derived for the intra-class and inter-class correlated error structures. Second-order rotatability conditions have been derived herein assuming the response follows non-normal distribution (any one of the above four distributions) and errors have a general correlated error structure. These conditions are further simplified under intra-class and inter-class correlated error structures, and second-order rotatable designs are developed under these two structures for the response having anyone of the above four distributions. It is derived herein that robust second-order rotatable designs depend on the respective error variance covariance structure but they are independent of the correlation parameter values, as well as the considered four response lifetime distributions.

• Journal of Korea Multimedia Society
• /
• v.25 no.6
• /
• pp.886-893
• /
• 2022

Outlier detection refers to the task of detecting data that deviate significantly from the normal data distribution. Most outlier detection methods compute an outlier score which indicates the degree to which a data sample deviates from normal. However, setting a threshold for an outlier score to determine if a data sample is outlier or normal is not trivial. In this paper, we propose a binary prediction method for outlier detection based on spectral clustering and one-class SVM ensemble. Given training data consisting of normal data samples, a clustering method is performed to find clusters in the training data, and the ensemble of one-class SVM models trained on each cluster finds the boundaries of the normal data. We show how to obtain a threshold for transforming outlier scores computed from the ensemble of one-class SVM models into binary predictive values. Experimental results with high dimensional text data show that the proposed method can be effectively applied to high dimensional data, especially when the normal training data consists of different shapes and densities of clusters.

• Journal for History of Mathematics
• /
• v.13 no.1
• /
• pp.1-14
• /
• 2000

The first part of this thesis discusses the Pearson's Curve Family which gives $\beta$distribution, $\Gamma$-distribution, $X^2$-distribution and t-distribution. The second part of this thesis gives some brief process of calculations for normal distribution density and t-distribution density by the 7-th type Curve of Pearson's Curve Family. Finally, a conclusion arrives that Student(Gosset) could not find out his famous 'Student's t-distribution' without his attending of 'Pearson's Differential Equation' class taught by Pearson himself when he was a senior student. However, if he had got a professorship at the Pearson Statistics Laboratory, the University of London, then he could not have found 'Student's t-distribution' for small sampling technique of modern statistics.

• The Pure and Applied Mathematics
• /
• v.11 no.1
• /
• pp.51-61
• /
• 2004

We find an easier formula to compute Hausdorff and packing dimensions of a subset composing a spectral class by local dimension of a self-similar measure on a self-similar Cantor set than that of Olsen. While we cannot apply this formula to computing the dimensions of a subset composing a spectral class by local dimension of a quasi-self-similar measure on a self-similar set on the way to a perturbed Cantor set, we have a set theoretical relationship between some distribution sets. Finally we compare the behaviour of a quasi-self-similar measure on a self-similar Cantor set with that on a self-similar set on the way to a perturbed Cantor set.

• Journal of Environmental Science International
• /
• v.8 no.3
• /
• pp.281-286
• /
• 1999

This study was conduced to examine the monthly and seasonal variation of $SO_2$, TSP, $O_3$ concentration in Dongsamdong, Pusan coastal area. And the characteristics of air pollution of this area was compared to Kwangbokdong in Pusan and Taehadong in Ullungdo. Monthly mean concentration of $SO_2$ and TSP showed lower than Kwangbokdong, $O_3$ was higher than Kwangbokdong. In case of $SO_2$, seasonal variation of Dongsamdong was remarkabler thn Kwangbokdong and the concentration difference of early morning and daytime was higher than Kwangbokdong. Taehadong showed very lower concentration as background area. In case of TSP, Dongsamdong was lower concentration and smaller diurnal change than Kwangbokdong, Taehadong showed very lower concentration as backgound area. In case of $O_3$, Dongsamdong was 10ppb higher than Kwangbokdong at daytime maximum concentration, diurnal change of concentration was higher, too. In case of frequency distribution of concentration, $SO_2$, and TSP at Dongsamdong showed higher frequency in low concentration class and $O_3$ showed in high concentration class as compared with Kwangbokdong.

• Communications for Statistical Applications and Methods
• /
• v.14 no.2
• /
• pp.287-299
• /
• 2007

We consider a multiclass queue where queued customers are served in their order of arrival at a rate which depends on the customer type. By using the asymptotic results obtained by Dabrowski et al. (2006) we calculate the sharp asymptotics of the stationary distribution of the number of customers of each class in the system and the distribution of the number of customers of each class when the total number of customers reaches a high level before emptying. We also obtain a fast simulation algorithm to estimate the overflow probability and compare it with the general simulation and asymptotic results.