• Journal of the Korean Data and Information Science Society
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• v.28 no.1
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• pp.87-98
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• 2017

The multivaiate empirical distribution function (MEDF) is defined in this work. The MEDF's expectation and variance are derived and we have shown the MEDF converges to its real distribution function. Based on random samples from bivariate standard normal distribution with various correlation coefficients, we also obtain MEDFs and propose two kinds of graphical methods to visualize MEDFs on two dimensional plane. One is represented with at most n stairs with similar arguments as the step function, and the other is described with at most n curves which look like bivariate quantile vector. Even though these two descriptive methods could be expressed with three dimensional space, two dimensional representation is obtained with ease and it is enough to explain characteristics of bivariate distribution functions. Hence, it is possible to visualize trivariate empirical distribution functions with three dimensional quantile vectors. With bivariate and four variate illustrative examples, the proposed MEDFs descriptive plots are obtained and explored.

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.422-428
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• 2011

This paper presents results from the theoretical analysis of the lateral load distribution for a railway bridge designed with PSC girders which is one of most popular types of bridge in Korea. Typically, 3 sets of intermediate cross beams within a span have been installed for lateral load distribution. In this paper, the effect on the lateral load distribution by the number of intermediate cross beams were examined by both simple grillage analysis and finite element method. This study showed that at least, one set of cross beams at midspan should be needed to ensure the proper load distribution. However, the effect of cross beams on the load distribution becomes not significant though more than one set of cross beams are installed. Therefore, only one set of cross beans at midspan is recommended for constructibility and economic efficiency.

• Journal of IKEEE
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• v.24 no.2
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• pp.385-391
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• 2020

Overcurrent and abnormal voltages in the distribution system can cause not only burden of power plant but also damage to customers. As a result, researches related to the distribution automation have been widely conducted by utilizing a real time digital simulation to improve the reliability of power supply through rapid failure handing, reduction of power failure intervals and failure recovery. However, the distribution automation systems using the real time digital simulator are expensive and limited to verify actual hardwares. Therefore, in this paper, an external hardware devices was developed based on the distribution system analysis results of the digital simulator. And real-time simulation and functional verification are implemented by the real feeder remote terminal units used in distribution automation. The effectiveness of the proposed system is verified through several experiments.

• Journal of the Korean Dietetic Association
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• v.26 no.4
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• pp.243-253
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• 2020

The purpose of this study was to set new guidelines for adenosine triphosphate (ATP) bioluminescence hygiene monitoring of distribution trays at children's foodservices. Five dietitians visited 223 foodservices (95 institutional, 128 small) to examine whether they adhered to the norms of 'Keeping distribution tray sanitary by washing/sanitizing' and 'Performing food distribution in a clean and appropriate way'. In this visit, dietitians swabbed 100 ㎠ area of the distribution trays twice, once for obtaining ATP measurements and the second time for Aerobic Plate Counts (APC) using 3M Petrifilm Plates. Chi-square test and ANOVA were applied using SPSS 23.0 software. SPSS 23.0 was used to conduct graphical and statistical analysis of the raw data of ATP measurements, which were further transformed by a Box-Cox transformation. The mean of APC from all the subjects inspected was 3.8×10²±2,102.0 CFU/100 ㎠. A total of 208 (93.3%) trays were observed within the acceptable limits of APC (Pass<5.0×10² CFU/100 ㎠). APCs taken at institutional foodservices showed significantly lower levels (1.4×10²±600.0 CFU/100 ㎠, P<0.01) compared to the small foodservices (5.5×10²±2,718.7 CFU/100 ㎠). No significant differences were observed between the two groups in ATP measurements and in the performance rate of 2 checklist items. As against the 93.3% APC adequacy from the total subjected inspection, total ATP adequacy (Pass≤300 RLU/100 ㎠) was only 71.7%. Therefore, more practical guidelines should be prepared for the assessment of the hygiene of distribution trays. In the graphical and statistical analysis, levels below 250 RLU/100 ㎠ was considered 'Pass', while equal to or greater than 350 RLU/100 ㎠ was considered 'Fail' for distribution trays.

• The Korean Journal of Applied Statistics
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• v.26 no.4
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• pp.611-622
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• 2013

Mudholkar and Tian (2002) proposed an entropy-based test of fit for the inverse Gaussian distribution; however, the test can be applied to only the composite hypothesis of the inverse Gaussian distribution with an unknown location parameter. In this paper, we propose an entropy-based goodness-of-fit test for an inverse Gaussian distribution that can be applied to the composite hypothesis of the inverse Gaussian distribution as well as the simple hypothesis of the inverse Gaussian distribution with a specified location parameter. The proposed test is based on the probability integration transformation. The critical values of the test statistic estimated by simulations are presented in a tabular form. A simulation study is performed to compare the proposed test under some selected alternatives with Mudholkar and Tian (2002)'s test in terms of power. The results show that the proposed test has better power than the previous entropy-based test.

• Journal of Distribution Science
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• v.17 no.5
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• pp.103-111
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• 2019

Purpose - This paper aims to examine a spirituality's impact on the posttraumatic interpersonal relationships of family violence with a structural equation model(SEM). This article starts with the research idea that family violence experience bring about negative emotion in terms of interpersonal relationship leading to the distribution of negative affect in social relationship. The research question of this study pinpoints on how family violence experience affects interpersonal relationship problems and how spirituality affects interpersonal relations problems. Based on the idea, we attempts to deal with spirituality's impact as a driving factor of transforming the distribution of negative affect. Research design, data, and methodology - The structural equation modelling(SEM) is employed as a analysis method of this study. SEM provides a chiefly cross-sectional statistical modelling method, and moreover it allows multiple variables to be associated with a latent variable in this analysis. 300 samples from Seoul, Gyeonggy and Gangwon are selected in the survey. We chose available 271 among them. Results - The results verify that trauma have placed an negative impact on personal relations. The study results also shows that the more serious get the degree of family violence trauma, the worse become interpersonal relationship problems. What is more interesting is that the degree of trauma's impact on interpersonal relation problems in male is higher than that of trauma's impact in female. It is mainly attributed to the fact that women are superior to men in terms of empathy ability and interpersonal relationship orientation. It can be noted that the well-managed spirituality will be able to make a great contribution towards reducing the degree of trauma caused by interpersonal relationships. Conclusions - The study results demonstrates that family violence have negative impacts on spirituality, while spirituality have an positive impacts on reduction the problems of interpersonal relationship. It has been found out that family violence trauma may cause negative affectivity in personal relations, which can distribute negative impacts regarding interpersonal relationship in society. This study also supports that spirituality will be able to function well as a helper, which may reduce the distribution of negative affect in society.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.39-46
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• 2001

In this paper we propose a new method that can be estimation the spectral power distribution of the light source from three-band images. the light source is estimated by dividing the reflected spectral power distribution of the maximum achromatic region(L(λ)) by the corresponding surface reflectance(Ο(λ)). In order to obtain reflected spectral power distribution of the maximum achromatic region from three-bend images, a modified gray world assumption algorithm is adapted. And the maximum surface reflectance is estimated using the principal component analysis method along with achromatic population. The achromatic population is created from a set of given Munsell color chips whose chroma vector is less than threshold. Cumulative contribution ratio of principal components from the first to the third for classified achromatic population was about 99.75%. The reconstruction of illumination spectral power distribution by using achromatic population and three-band digital images captured under various light source was examined, and evaluated by RMSE between the original and reconstructed illumination spectral power distribution. This work was supported by grant No (2000-1-30200-005-3) from the Basic Research Program of the Korea Science & Engineering Foundation.

• Journal of Korean society of Dental Hygiene
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• v.20 no.5
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• pp.743-752
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• 2020

Objectives: The objectives of this study were to investigate the distribution and level of periodontopathic bacteria with the general characteristics and oral health condition of the elderly. Methods: A total of 335 elderly individuals aged 65 years or older who lived in Ganghwa-gun, Incheon, were included in the study. Oral examination, investigation through a questionnaire, and collection of saliva were carried out. The collected saliva was analyzed for the distribution and levels of bacteria (red and orange complex bacteria) by real-time polymerase chain reaction. Statistical analyses were performed using chi-square test, t-test, one-way analysis of variance, and Pearson's correlation coefficient with SAS statistical software version 9.4. Results: Among the general characteristics, there were significant differences in the distribution of Porphyromonas gingivalis, Treponema denticola, and Parvimonas micra depending on sex, age, and dental visits (p<0.05). The number of remaining teeth and denture use were related to the distribution of periodontopathic bacteria, except T. denticola (p<0.05). Additionally, periodontitis was related to the distribution of P. gingivalis (p<0.05). As the number of remaining teeth increased, the copy number of red and orange complex bacteria also increased (p<0.05). Those individuals who did not use dentures and had periodontal disease had more periodontopathic bacteria (p<0.05). Conclusions: The distribution and copy number of periodontopathic bacteria in the elderly were more related to oral health condition than to general characteristics. In particular, the distribution and copy number of periodontopathic bacteria were higher in subjects with multiple remaining teeth, no dentures, and periodontal disease.

• Journal of Environmental Impact Assessment
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• v.21 no.4
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• pp.593-607
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• 2012

The Ministry of Environment have started the 'National Ecosystem Survey' since 1986. It has been carried out nationwide every ten years as the largest survey project in Korea. The second one and the third one produced the GIS-based inventory of species. Three survey methods were different from each other. There were few studies for species distribution using national survey data in Korea. The purposes of this study are to test species distribution models for finding the most suitable modeling methods for the National Ecosystem Survey data and to investigate the modeling results according to survey methods and taxonominal group. Occurrence data of nine species were extracted from the National Ecosystem Survey by taxonomical group (plant, mammal, and bird). Plants are Korean winter hazel (Corylopsis coreana), Iris odaesanensis (Iris odaesanensis), and Berchemia (Berchemia berchemiaefolia). Mammals are Korean Goral (Nemorhaedus goral), Marten (Martes flavigula koreana), and Leopard cat (Felis bengalensis). Birds are Black Woodpecker (Dryocopus martius), Eagle Owl (Bubo Bubo), and Common Buzzard (Buteo buteo). Environmental variables consisted of climate, topography, soil and vegetation structure. Two modeling methods (GAM, Maxent) were tested across nine species, and predictive species maps of target species were produced. The results of this study were as follows. Firstly, Maxent showed similar 5 cross-validated AUC with GAM. Maxent is more useful model to develop than GAM because National Ecosystem Survey data has presence-only data. Therefore, Maxent is more useful species distribution model for National Ecosystem Survey data. Secondly, the modeling results between the second and third survey methods showed sometimes different because of each different surveying methods. Therefore, we need to combine two data for producing a reasonable result. Lastly, modeling result showed different predicted distribution pattern by taxonominal group. These results should be considered if we want to develop a species distribution model using the National Ecosystem Survey and apply it to a nationwide biodiversity research.

• The Korean Journal of Applied Statistics
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• v.25 no.1
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• pp.101-114
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• 2012

In car insurance, the loss ratio is the ratio of total losses paid out in claims divided by the total earned premiums. In order to minimize the loss to the insurance company, estimating extreme quantiles of loss ratio distribution is necessary because the loss ratio has essential prot and loss information. Like other types of insurance related datasets, the distribution of the loss ratio has heavy-tailed distribution. The Peaks over Threshold(POT) and the Hill estimator are commonly used to estimate extreme quantiles for heavy-tailed distribution. This article compares and analyzes the performances of various kinds of parameter estimating methods by using a simulation and the real loss ratio of car insurance data. In addition, we estimate extreme quantiles using the Hill estimator. As a result, the simulation and the loss ratio data applications demonstrate that the POT method estimates quantiles more accurately than the Hill estimation method in most cases. Moreover, MLE, Zhang, NLS-2 methods show the best performances among the methods of the GPD parameters estimation.