• Journal of the Korea Society of Computer and Information
• /
• v.11 no.1 s.39
• /
• pp.45-53
• /
• 2006

Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, Goel-Okumoto and Yamada-Ohba-Osaki model was reviewed, proposes the $x^2$ reliability model, which can capture the increasing nature of the failure occurrence rate per fault. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on SSE, AIC statistics and Kolmogorov distance, for the sake of efficient model, was employed. Analysis of failure using real data set, SYS2(Allen P.Nikora and Michael R.Lyu), for the sake of proposing shape parameter of the $x^2$ distribution using the degree of freedom, was employed. This analysis of failure data compared with the $x^2$ model and the existing model using arithmetic and Laplace trend tests, Kolmogorov test is presented.

• Journal of the Korean Data and Information Science Society
• /
• v.27 no.2
• /
• pp.373-380
• /
• 2016

Even though Likert type data is ordinal scale, many researchers who regard Likert type data as interval scale adapt as parametric methods. In this research, simulations have been used to find out a proper analysis of Likert type data. The locations and response distributions of five point Likert type data samples having diverse distribution have been evaluated. In estimating samples' locations, we considered parametric method and non-parametric method, which are t-test and Mann-Whitney test respectively. In addition, to test response distribution, we employed Chi-squared test and Kolmogorov-Smirnov test. In this study, we assessed the performance of the four aforementioned methods by comparing Type I error ratio and statistical power.

• Journal of the Korean Data Analysis Society
• /
• v.20 no.6
• /
• pp.2813-2827
• /
• 2018

Progressive censoring schemes have become quite popular in reliability study. Under progressive censored data, however, some units can be failed between two points of observation with exact times of failure of these units unobserved. For example, loss may arise in life-testing experiments when the failure times of some units were not observed due to mechanical or experimental difficulties. Therefore, multiply progressive censoring scheme was introduced. So, we derives a maximum likelihood estimator of the parameter of exponential distribution. And we introduced the goodness-of-fit test statistics using order statistic and Lorenz curve. We carried out Monte Carlo simulation to compare the proposed test statistics. In addition, real data set have been analysed. In Weibull and chi-squared distributions, the test statistics using Lorenz curve are more powerful than test statistics using order statistics.

• The korean journal of orthodontics
• /
• v.52 no.3
• /
• pp.165-171
• /
• 2022

Objective: This cross-sectional study aimed to investigate the characteristics of malocclusions in scoliotic patients through clinical examinations. Methods: Fifty-eight patients with idiopathic scoliosis (IS) and 48 patients with congenital scoliosis (CS) participated in the study. A randomly selected group of 152 orthopedically healthy children served as the control group. Standardized orthodontic and orthopedic examination protocols were used to record the occlusal patterns and type of scoliosis. Assessments were made by three experienced orthodontists and a spinal surgery team. The differences in the frequency distribution of occlusal patterns were evaluated by the chi-squared test. Results: In comparison with patients showing IS, patients with CS showed a higher incidence of Cobb angle ≥ 45° (p = 0.020) and included a higher proportion of patients receiving surgical treatments (p < 0.001). The distribution of the Angle Class II subgroup was significantly higher in the IS (p < 0.001) and CS (p = 0.031) groups than in the control group. In comparison with the healthy controls, the CS and IS groups showed significantly higher (p < 0.05) frequencies of asymmetric molar and asymmetric canine relationships, upper and lower middle line deviations, anterior deep overbite, unilateral posterior crossbite, and canted occlusal plane, with the frequencies being especially higher in CS patients and to a lesser extent in IS patients. Conclusions: Patients with scoliosis showed a high frequency of malocclusions, which were most obvious in patients with CS.

• Korean Journal of Human Ecology
• /
• v.19 no.3
• /
• pp.537-553
• /
• 2010

Culture represents forms of life appeared in various dimensions. Advertisements which represent these forms of life show the most important social and cultural phenomenon. The necessity of research on the cultural characteristics of society has been raised because the effectiveness of advertisement could have been varied depending on the cultural value. Moreover, within a society, values reflected by advertisements tend to vary in different eras. Thus, this study aims to clarify the differences between cultural values from different eras through an analysis of cultural characteristics and symptoms with consideration of the time flow. This study also examines the meanings of cultural characteristics highlighted by the study. For the investigation, two Korean women's magazines were selected, from 1955 to 2008. Data were analyzed using chi-squared test which was conducted with Crosstab using the PASW statistics 17.0 Program. The results were as follows: there were changing aspects from traditional values to modern values by years. Additionally, each period was described using several keywords. The keywords were divided by decade: in the '50s keywords were 'lifestyle change', 'material value increase' and the 'challenge to traditional values', in the '60s keywords were 'American culture acceptance', 'material success', in the '70s keywords were 'the rise of nonmaterial value', 'rationalism' and 'egalitarianism', in the '80s 'individualism', 'Life style and culture group differentiation', 'conspicuous consumption', in the '90s 'globalization', 'emphasis on personality sensitivity', 'health-oriented', 'improve the quality of life', while in the '00s keywords were 'spread of digital life', 'rational consumption patterns', 'the 3rd distribution'. Through the research, important changes in the cultural characteristics of Korea were observed. Furthermore, we may be able to think of the most effective way of advertising by identification of the cultural characteristics of the society.

• The Journal of Advanced Prosthodontics
• /
• v.5 no.3
• /
• pp.351-358
• /
• 2013

PURPOSE. This retrospective study analyzed the distribution of the dental implants with regards to age and gender of the patients and type of indication for the implant therapy, as well as the location, dimension and type of the implants. MATERIALS AND METHODS. The data of demographics (age and gender), type of indication for implant therapy, anatomical location, dimensions (length and diameter) and type (bone and tissue level) of 1616 implants were recorded from patient charts between January 2000 and January 2010. Descriptive statistics were analyzed using a chi-squared test for demographic parameters, type of indication, tooth position, anatomical location, implant dimensions and type (${\alpha}$=.05). RESULTS. The patient pool comprised of 350 women and 266 men, with a mean age of $52.12{\pm}13.79$ years. The difference in n% of the implants of the age groups was statistically significant between the types of indications. The difference in the position of the implants was statistically significant between the n% of the implants of all age groups. Gender did not significantly vary, except that the diameter of the implants was significantly higher for the standard diameter implants in males. The difference between the implant positions was statistically significant when considered according to indication. The relationship between implant length and anatomical location was statistically significant. CONCLUSION. The indication for dental implant use is age dependent and the type and size of the implant seems to be strongly related to the location of the implant.

• The Korean Journal of Food And Nutrition
• /
• v.28 no.4
• /
• pp.612-619
• /
• 2015

The present study was designed to investigate health-related life habits, food preference, body composition for proper dietary habits, health promotion of communities in Incheon area. The effects of personal characteristics and health-related life habits such as gender, age, having breakfast, smoking, drinking, and exercise were analyzed using a surveying. 961 community subjects (262 males and 699 females) were investigated using a questionnaire and Inbody. Data were analyzed by descriptive statistics, chi squared test, and one-way ANOVA (analysis of variation) with SPSS/WIN 21.0. The result of gender distribution showed there were 262 males and 699 females, and with respect to the effect of gender on health-related life habits, smoking, drinking, and exercise showed significant differences (p < 0.05), whereas having breakfast was not significantly difference (p>0.05). Therefore, the present provide evidence of a relationship between health-related life habits and gender. Regarding the effect of BMI on health-related life habits, exercise showed significant differences (p < 0.05), whereas smoking, drinking, and having breakfast were not significantly difference (p>0.05). Thus, the present study also provides evidence of a relationship between health-related life habits and BMI. Our analysis shows that food preference and body composition were significant different from health-related life habits such as smoking, drinking, exercise, and having breakfast (p < 0.05). Our analysis showed that body composition was significant differences from health related habits such as smoking, drinking, exercise, and breakfast (p < 0.05). In conclusion, the present study suggests that diet guidelines support and improve health promotion designed by communities.

• Imaging Science in Dentistry
• /
• v.43 no.1
• /
• pp.25-30
• /
• 2013

Purpose: This study was performed to determine the prevalence of bifid mandibular condyles (BMCs) in asymptomatic and symptomatic temporomandibular joint (TMJ) subjects with no traumatic history, and to assess their impact on clinical and radiographic manifestations of TMJ. Materials and Methods: A total of 3,046 asymptomatic and 4,378 symptomatic patients were included in the study. Cone-beam computed tomography (CBCT) images were reviewed for bifid condyles. T-tests were used to compare the frequency of BMCs when stratified by symptom, gender, and side. In BMC patients, the clinical features of pain and noise, osseous changes, and parasagittal positioning of the condyles were compared between the normally shaped condyle side and the BMC side using chi-squared tests. Results: Fifteen (0.49%) asymptomatic and 22 (0.50%) symptomatic patients were found to have BMCs. Among the bilateral cases, the number of condyles were 19 (0.31%) and 25 (0.29%), respectively. No statistically significant differences were found between asymptomatic and symptomatic patients, between female and male patients, or between the right and left sides (p>0.05). Compared with the normally shaped condyle side, the BMC side showed no statistically significant differences in the distribution of pain and noise, parasagittal condylar position, or condylar osseous changes, with the exception of osteophytes. In the symptomatic group, osteophytes were found more frequently on the normally shaped condyle side than the BMC side (p<0.05). Conclusion: BMCs tended to be identified as an incidental finding. The presence of BMC would not lead to any TMJ symptoms or cause osseous changes.

• The Journal of the Acoustical Society of Korea
• /
• v.20 no.2
• /
• pp.3-9
• /
• 2001

In this paper, a random number generator for simulation of speech-waveform coders was designed. A random number generator having a desired probability density function and a desired power spectral density is discussed and experimental results are presented. The technique is based on Sondhi algorithm which consists of a linear filter and a memoryless nonlinearity. Several methods of obtaining memoryless nonlinearities for some typical continuous distributions are discussed. Sondhi algorithm is analyzed in the time domain using the diagonal expansion of the bivariate Gaussian probability density function. It is shown that the Sondhi algorithm gives satisfactory results when the memoryless nonlinearity is given in an antisymmetric form as in uniform, Cauchy, binary and gamma distribution. It is shown that the Sondhi algorithm does not perform well when the corresponding memoryless nonlinearity cannot be obtained analytically as in Student-t and F distributions, and when the memoryless nonlinearity can not be expressed in an antisymmetric form as in chi-squared and lognormal distributions.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.33 no.5
• /
• pp.295-301
• /
• 2019

The purpose of this study is to assess potential effects of the effects of Korean Medicine treatments on condyloma. Retrospective study of 194 patients with diagnosed condyloma in Saengki Korean Medicine Clinic from October 2013 to September 2018 was done. Patients were treated with Korean Medicine treatments such as herbal treatment, pharmacopuncture and moxibustion. The data has been analyzed by chi-squared distribution and t-test. A total of 194 patients were 148 males and 46 females. In the aspect of diagnosis, newly diagnosed patients were 96 and recurrent patients were 98. After the treatment, in the light of size complete clearances were 110 patients, partial clearances were 63 and non responses were 21. And in the light of number complete clearances were 110 patients, partial clearances were 68 and non responses were 16. In complete clearance group, the relation among the treatment period, sex, age, and the site of wart showed statistically significant. There were 3 recurrences of warts in the 6 months of follow-up observation for 110 of clearance group. No major side effects related to the treatment were found. As the result of t-test shows, the Korean Medicine treatment we had applied revealed as statistically effective on both number(t=11.471, p<.001) and size(t=11.951, p<.001) of the wart. The result of this study suggests that additional treatment of Korean medicine such as acupuncture and moxibustion treatment could be effective on condyloma patients.