• Journal of The Korean Astronomical Society
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• v.48 no.1
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• pp.75-82
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• 2015

We use a volume-limited sample of quasars in the Sloan Digital Sky Survey (SDSS) DR7 quasar catalog to identify quasar groups and address their statistical significance. This quasar sample has a uniform selection function on the sky and nearly a maximum possible contiguous volume that can be drawn from the DR7 catalog. Quasar groups are identified by using the Friend-of-Friend algorithm with a set of fixed comoving linking lengths. We find that the richness distribution of the richest 100 quasar groups or the size distribution of the largest 100 groups are statistically equivalent with those of randomly-distributed points with the same number density and sky coverage when groups are identified with the linking length of $70h^{-1}Mpc$. It is shown that the large-scale structures like the huge Large Quasar Group (U1.27) reported by Clowes et al. (2013) can be found with high probability even if quasars have no physical clustering, and does not challenge the initially homogeneous cosmological models. Our results are statistically more reliable than those of Nadathur (2013), where the test was made only for the largest quasar group. It is shown that the linking length should be smaller than $50h^{-1}Mpc$ in order for the quasar groups identified in the DR7 catalog not to be dominated by associations of quasars grouped by chance. We present 20 richest quasar groups identified with the linking length of $70h^{-1}Mpc$ for further analyses.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.24 no.3
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• pp.27-36
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• 2011

Objective : The purpose of this clinical research was to analyze the correlation between disease severity and disease specific quality of life adjusted by general quality of life measure in adult patients with atopic dermatitis attending Wonkwang Univ. Sanbon Oriental Medical Center. Methods : A total of 35 patients participated in atopic dermatitis clinical trial from June 1st, 2010 to June 30th, 2011 were included in this study. SCORing Atopic Dermatitis(SCORAD) index, Dermatologic Life Quality Index(DLQI), Health Utility Index III(HUI-III) and EuroQoL 5-Dimension(EQ-5D) have been estimatied. Baseline statistical analysis and normality test were done by using Student t-test, Shapiro-Wilk test and ladder test. Pearson analysis and Spearman analysis were conducted to examined the correlation of each variables. Hierachial regression analysis was performed using related variables. Statistical significance was achieved if the probability was less than 5%. Results : There were statistically significance between DLQI and SCORAD index, and also between DLQI and EQ-5D. However there was no significant between DLQI and HUI-III. In the hierachial regression analysis, after adjusting for demographic variables (gender, age) and general quality of life (EQ-5D), SCORAD index significantly predict the intensity of disease specific quality of life (DLQI). Conclusions : We confirmed the correlation between SCORAD index and DLQI, and developed the inference for regression equation of DLQI using SCORAD index, EQ-5D and demographic variables.

• The Korean Journal of Applied Statistics
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• v.21 no.4
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• pp.615-620
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• 2008

In engineering experiments, 'Sometimes Pooling Rules' to remove insignificant terms from the model has been implemented to increase the power of detecting the small size of main effects when the preliminary test of higher order interaction effects declare to be insignificant. In this note, we review the sometimes pooling rules in the literature and also study the probability of the length of 95% confidence interval of ${\mu}_1-{\mu}_2$ of the comparison of two independent samples being shorter than that of the paired comparison at the various level of significance ${\alpha}_1$ of the preliminary test and the insufficient number of blocks n in [2,13], given the block effects being pooled to the error term. This study supports that the sometimes pooling results in the power improvement of the main effects.

• Journal of Korean society of Dental Hygiene
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• v.9 no.3
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• pp.403-414
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• 2009

Objectives : This research aimed at investigating middle school students' knowledge and behavior of oral hygiene according to the knowledge level of parents on this ground, provide basic data for establishing a more effective school and home oral hygiene education program for students. Methods : Students were selected from four secondary schools in J city by convenience sampling, which is non probability sampling; then, the final analysis was performed on 272 self-administered questionnaires. For statistical analysis, SPSS 10.0 for Windows was used to carry out frequency analysis and chi-square test at the 0.05 significance level in determining statistical significance. Results : 1. 50.0% had periodontal disease caused by 'weak periodontal', in the case of the father of academic ability was middle school graduated. 2. Showed lowly what is behavior prevention as regularly oral examination for the oral health, in the case of the parents's academic ability was low(in the case of the mother's academic ability was middle school graduated, 34.5% received regular oral examination every three months). 3. In the case of, the father and mother of academic ability was middle school graduated showed 50%, 44.8% about the teeth never important in the life. 4. In the case of, the father and mother of academic ability was middle school graduated showed 37.5%, 31.0% about time for the tooth brushing is under 1 minute per one time. Conclusions : It's very important for middle school student's oral health that the oral health education and oral hygiene attitude in their home. especially middle school student's attitude was controlled by parents' knowledge level. This like basic data will be useful in establishing program of school oral health and individual oral hygiene attitude in their home.

• Korean Journal of Head & Neck Oncology
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• v.13 no.1
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• pp.30-34
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• 1997

Objectives: Calcification of the thyroid nodule has been reported to have a close relationship with differentiated thyroid carcinoma, however there are limited studies on the relationship between the calcified thyroid nodule and thyroid malignancy. The authors studied the clinical significance of calcification within the thyroid nodule. Materials and Methods: There were total of 60 patients who underwent surgery for calcified thyroid nodules which were identified from plain neck X-ray, ultrasound and computed tomography during the period January 1991 to June 1996 at the Department of Otorhinolaryngology-Head and Neck Surgery of Korea University Hospital. Six patients were not included because of recurrence and previous thyroid surgery. Histopathologic and radiologic analysis was done on the remaining 54 patients. Results: Results showed that 25 of 54 cases(46%) to be malignant histopathologically. Of the 25 malignant cases, papillary carcinoma was the most common with 22 cases followed by 2 cases of undifferentiated carcinoma and I case of medullary carcinoma. Statistically high incidence of malignancy was observed when the consistency of calcified thyroid nodule was solid, shape of calcification was irregular and inhomogenous, and adhesion of calcified thyroid nodule to the regional structure was present. Conclusion: The probability that a thyroid nodule is malignant has been reported to be 3­20%. However, about half of the thyroid nodules with calcification found to be malignant on this study, calcification of the thyroid nodule can be used as a guideline for detecting thyroid malignancy.

• Korean Journal of Logic
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• v.20 no.1
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• pp.21-67
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• 2017

In this paper, I critically examine Sartorio's (2006) argument for disjunctive cause, and put forth disjunctive causal structure in a different way. I show that the disjunctive causal structure meets not just what Sartorio means to claim but also our understanding of causal responsibility. First, I introduce Sartorio's argument for disjunctive cause. Second, I critically discuss Sartorio's responses to the criticisms of her arguments for disjunctive cause, and propose another problem with her arguments. Finally, I explicate in a different way Sartorio's disjunctive cause in terms of disjunctive causal structure founded on moderate variables, causal interaction, and probability trajectory. I notice, regarding the disjunctive causal structure, the role of causal interaction of cause events with moderate variables. I reveal, regarding the disjunctive causal structure, the significance of indetermination of cause events and effect events for our understanding of causal responsibility. I show that the disjunctive causal structure guides us more convincingly to assign causal responsibility to an agent. I come to three conclusions. First, there is no disjunctive cause event Sartorio argues for. Second, propensities of events to be causally connected to an effect event constitute disjunctive relation. Third, we should notice indetermination of cause events and effect events while assigning causal responsibility to an agent.

• Journal of Wetlands Research
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• v.6 no.4
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• pp.45-57
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• 2004

This study analyzed the effect of land-use enhancement benefits with the flood safety which it is not quantified in the flood damage analysis, Korea. The land-use enhancement benefits mean the enhancement of land-use value according to the rise of flood safety of the protected area by the flood control projects and we performed the analysis of land-use enhancement benefits with the publicly announced land price which can objectively represent the land-use value of a specific area. We verified the statistical significance of the floating rate of land price according to the effects of flood control projects and the characteristics of a river through the analysis of variance. As a result of the verification, the increase of land-use value was represented by the net annual average floating rate of land price. The flood safety was classified as flood damage potential and flood prevention capacity. The flood damage potential was classified according to the rate of urbanization and flood prevention capacity was represented by the conditional annual non-exceedance probability obtained from the frequency analysis with uncertainty for the flood discharge. The study areas were small urban cities and we calculated the conditional annual non-exceedance probabilities of 200-year flood event for the levees constructed with the conditions of 10- and 50-year design frequency. The result was shown that the net annual average floating rate of land price would be raised nearly 5 times for 10%-increase of the conditional annual non-exceedance probability in small city areas.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.1
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• pp.147-155
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• 2015

The existing field survey and aerial photography involve the waste of manpower and economic loss in the coastline survey. To minimize these disadvantages, the digitization for efficient coastline extraction was conducted in this study using the points extracted from the standard coastline of the approximate highest high water and the diverse satellite images (KOMPSAT-3, SPOT-5, Landsat-8 and Quickbird-2), and the comparative accuracy analysis was conducted. The differences between the standard coastline points of the approximate highest high water and the coastline of each satellite were smallest for KOMPSAT-3, followed by Quickbird-2, SPOT-5 and Landsat-8. The significant probability from between the multipurpose applications satellite and Quickbird-2 (significant probability two-tailed) was statistically significant at 1% significance level. Therefore, high-resolution satellite images are required to efficiently extract the coastline, and KOMPSAT-3, from which images are easily acquired at a low cost, will enable the most efficient coastline extraction without external support.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.121-126
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• 2013

Background: Significance of HPV infection and genic mutation of APC and K-ras in rectal cancer has been investigated but not clarified. The objective of our study was to investigate these parameters in patients with rectal cancer to analyze correlations with biological behaviour, to determine relationships among the three, and also to demonstrate survival prognosis effects. Methods: From December 2007 to September 2008, 75 rectal cancer cases confirmed by histopathology in the Tumor Hospital of Xinjiang Medical University were enrolled. The control group consisted of normal rectal mucous membrane taken simultaneously, a least 10 cm distant from the carcinoma fringe. HPV DNA, the MCR of APC and exon-1 of K-ras were detected by PCR and PCR-SSCP. All results were analyzed in relation to clinical pathological material, using chi-square and correlation analysis via SPSS.13 and Fisher's Exact Probability via STATA. 9.0. All 75 patients were followed up for survival analysis using Kaplan-Meier and Log-rank tests. Results: 55 out of 75 cases demonstrated gene HPV L1 while it was notdetected in normal rectal mucosa tissue. HPV infection was correlated with age and lymphatic metastasis (P<0.05) but not other characteristics, such as ethnicity, tumor size, histological type, tumor type, Duke's stage and infiltration depth. Some 43 cases exhibited APC genic mutation (57.3%) and 34 K-ras genic mutation (45.3%). APC genic mutation was correlated with gender(P<0.05), but not age, histological type, infiltration depth, lymphatic metastasis and Duke's stage. In 55 cases of rectal cancer with HPV infection, there were 31 cases with genic mutation of APC (56.4%) and 24 with genic mutation of K-ras (43.6%). For the 20 cases of rectal cancer with non-HPV infection, the figures were 12 cases (60%) and 10 (50.0%), respectively, with no significant relation. Survival analysis showed no statistical significance for K-ras genic mutation, APC genic mutation or HPV infection (P>0.05). However, the survival time of the patients with HPV infection was a little shorter than in cases without HPV infection. Conclusions: Our results suggest that HPV infection might be an important factor to bring about malignant phenotype of rectal cancer and influence prognosis. Genic mutation of APC and K-ras might be common early molecular events of rectal cancer, but without prognostic effects on medium-term or early stage patients with rectal cancer.

• Proceedings of the Korean Society for Information Management Conference
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• 2002.11a
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• pp.23-65
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• 2002

This study is to consider varying factors of internal/external informational and operational environments in libraries, and develop a new evaluation indicators for university libraries in digital environments. In order to do this research, the previous works have been investigated, and the Delphi study and our own analysis have been performed. The main research results are as follows. First, the results through the Delphi method that was to adopted to verify evaluation items and indicators determined by the literature review show that the repressed values for each evaluation category is greater than 3.00. overall average is 4.02. and standard deviation is ranged from 0.40 to 0.62 for each category. This means that the evaluation indicators are valid. Second, the factor analysis was performed to verify the construct validity of evaluation indicators. As a result. the cumulative variance of evaluation indicators consisting of 11 dimensions per factor is 72.733%. In turn, this result shows that the validity of these indicators is very reliable. Third, t-test and one way ANOVA are performed within significance probability 0.05 in order to verify differences in each librarians point of views for the degree of importance in evaluation indicators. The results show that these evaluation indicators are verified to be appropriate since there is no significant difference. Based on the Delphi study and our own analysis. we developed a new evaluation indicators that consists of 7 evaluation categories, 35 evaluation items, and 92 evaluation indicators.