• The Korean Journal of Applied Statistics
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• v.29 no.4
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• pp.657-678
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• 2016

This study deals with the effect of online word-of-mouth (OWOM) variables on the box office. From the result of statistical analysis on 276 films with audiences of more than five hundred thousand released in the Korea from 2012 to 2015, it can be seen that the variables showing the size of OWOM (such as the number of the portal movie rater, blog, and news after release) are associated more with the box office than the portal movie rating showing the direction of OWOM as well as variables showing the inherent properties of the film such as grade, nationality, release month, release season, directors, actors, and distributors.

• Journal of agricultural medicine and community health
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• v.46 no.3
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• pp.171-185
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• 2021

배경: 2015년 한국의 중동호흡기증후군 유행에서 지역간 치명률의 차이는 극명하였다. 이 연구는 대전 클러스터와 다른 지역 간의 치명률의 관련된 일반적 특성 및 역학적 요인을 밝히고저 하였다. 방법: 입원병원 소재지를 기준으로 대전과 타 지역으로 구분하여 관련변수에 따른 카이제곱검정 및 피셔정확검정 등으로 분석하였다. 대전과 다른 지역의 치명률(CFR)의 차이와 관련된 요인을 분석하기 위하여 단변량 및 다변량 로지스틱 회귀분석를 실시하였다. 결과: 모형 I에서는 65세 이상 연령군일수록 7.12배(95% CI 2.33-21.8)(p=0.001), 동반질환이 있는 경우 10.29배(95% CI 2.94-36.06)(p<0.001), 잠복기가 7일 이하인 경우가 8.55배(95% CI 2.54-26.7), 입원기간이 17일 이하인 경우 10.08배(95% CI 2.99-31.9)(p<0.001) 등이었으며, 모형 II에서는 65세 이상 연령군일수록 5.34배(95% CI 1.65-17.2)(p=0.005), 잠복기가 7일 이하인 경우가 6.70배(95% CI 1.96-22.89), 입원기간이 17일 이하인 경우 8.90배(95% CI 2.59-30.6)(p=0.001), 동반질환에서 암의 경우에서 7.15배(95% CI 1.64-31.14)(p=0.009) 등이었다. 결론: 2015년 한국 중동호흡기증후군 유행에서 대전 클러스터의 높은 치명율은 연령(≥65세), 동반질환(특히 암), 잠복기(≤7일), 입원기간(≤17일) 등이 유의한 변수로 도출되었다.

• Journal of Digital Convergence
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• v.21 no.2
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• pp.17-25
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• 2023

The purpose of this study was to analyze the characteristics of elderly motorcycle accidents according to data from elderly inpatients to prepare prevention measures for the elderly against injury in motorcycle accidents. Chi-squared test, independent sample t-test, and canonical correlation analysis were performed on the Korea Disease Control and Prevention Agency's National Hospital Discharge In-depth Injury Survey data from 2015 to 2019, from which the records of 1,384 elderly inpatients hospitalized because of motorcycle accidents were obtained. intracranial injury(S06) was the most common care and treatment characteristic for both age groups. The most frequent injury site was the head and neck, and the most frequent injury type was a fracture. The above findings show that prevention education and policy formulation at the national level are necessary to identify and manage the factors of elderly motorcycle accidents. This study provides basic data for developing measures and policies to prevent and reduce injuries, making it significant for public health causes.

• Journal of Wetlands Research
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• v.10 no.2
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• pp.173-178
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• 2008

The habitat composition in the Han-river estuary, where white-naped crane(Grus vipio; endangered migrating bird) spend winter, was analysed by the geographic information system(GIS). And the habitat use pattern of white-naped crane collected by satellite tracking method was analysed. The % composition of seven habitat categories of land cover classification was compared for the buffers of radii 100 m, 200 m, 500 m, and 1 km, respectively, around the white-naped crane position point(n=228), and the statistical analysis was done using chi-square test. The results showed no selective use of habitat area by white-naped crane in the buffers of 100 m, 200 m and 500 m, but showed clear selection of habitat use (p < 0.05) in the case of 1 km buffer.

• Journal of the Korean Data and Information Science Society
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• v.20 no.1
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• pp.1-9
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• 2009

Let us consider that the variance function in regression model has a discontinuity/change point at unknown location. Yu and Jones (2004) proposed the local polynomial fit to estimate the log-variance function which break the positivity of the variance. Using the local polynomial fit, Huh (2008) estimate the discontinuity point of the log-variance function. We propose a test for the existence of a discontinuity point in the log-variance function with the estimated jump size in Huh (2008). The proposed method is based on the asymptotic distribution of the estimated jump size. Numerical works demonstrate the performance of the method.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1125-1128
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• 2013

본 논문에서는 여성들의 개별 패션 선호도로부터 패션 선호 패턴을 분석하고 이를 이용하여 고객에게 맞는 의류를 추천하는 모바일 의류 추천 시스템을 제안한다. 패선 선호관련 설문조사로부터 대응표본 T-검정 방법을 이용하여 선호 특성과 의류와의 유효한 관계를 찾고, 이를 바탕으로 선호 특성에 따른 의류 분류 기준을 작성하였으며, 카이제곱 검정 방법을 통해 선호 특성과 의류 사이의 연관성을 파악하고 선호 특성에 따른 선호 의류 추천을 위한 규칙을 도출하였다. 이러한 규칙을 활용하여 각 사용자의 구입의사 및 패선 선호 특성에 따른 의류를 추천해 주는 시스템을 구현하였으며, 이에 대한 만족도를 조사한 결과 10 점 만점에 7.1 점으로 나타났다. 본 논문에서 제안한 모바일 의류 추천 시스템을 통해 사용자는 선호 의류를 추천 받을 수 있으며, 이로부터 제품의 정보 부족으로 발생하였던 모바일 쇼핑의 문제점을 해결할 수 있을 것이다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.102-102
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• 2023

벤포드 법칙(Benford's Law)은 실생활에서 관찰되는 수치 데이터를 첫 자리 숫자에 따라 분류할 때 첫 자리의 숫자가 커질수록 그 분포가 점차 감소되는 현상을 말한다. 이러한 벤포드 법칙은 일반식으로 도출하여 다양한 자릿수로 확장하여 적용할 수 있는 연구결과가 제시되었으며, 회계학, 사회과학, 물리학, 컴퓨터과학, 생물학 등 다방면의 수치 자료에서 그 유효성이 확인되고 있다. 자릿수의 관찰빈도를 분석하는 것만으로 많은 양의 실생활 데이터에서 빠르고 쉽게 데이터 조작여부를 탐지하거나 1차적인 데이터 품질검사에 효과적으로 활용되고 있다. 본 연구에서는 다학제적 연구의 측면에서 수학·물리적 법칙인 벤포드 법칙을 일유량 등 다양한 수문학 측정자료에 적용하여 그 적용가능성을 확인하고 자료의 불균질성과 신뢰성을 빠르게 탐지할 수 있는 방법론을 제시하고자 한다. 수문자료는 공인심의를 통해 자료의 신뢰도를 확보하고 있으나 확정·배포까지 약 2년이 소요되어 활용기간 단축에 대한 사용자 요구가 지속되고 있는 실정이다. 따라서 본 연구에서는 분석대상 데이터의 자릿수 관찰빈도가 벤포드 법칙에 의한 예상자릿수 빈도를 따르는지 여부에 대한 가설을 설정하고 카이제곱 검정 또는 Kolmogorov-Smirnov(K-S) 검정 등을 통해 적합도에 대한 통계적 유의미함을 분석함으로써 대략적으로나마 빠르고 쉽게 측정자료의 신뢰성을 판단할 수 있다. 본 연구는 다양한 학문과의 결합을 통한 새로운 접근을 시도함으로써 빅데이터 시대에 효과적으로 수자원의 개발, 관리 및 운영의 의사결정을 하는데 도움이 될 수 있을 것으로 판단된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.460-471
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• 2019

The aim of this study was to examine the scale and market share of Chinese's research facility & equipment in the domestic research equipment market of basic and analytical science field for analyzing the difference of the number and amount of construction by year of acquisition, national research facility equipment standard classification code, and type of institution based on the information of the research equipment invested by the Korean government for the past 14 years. In addition, we analyzed the correlation among the year of acquisition, equipment standard classification code, and type of institution variables. As of January 1 2019, from 2005 to 2018, 50 Chinese's research facilities & equipments (main equipment with a construction cost of 30 million won or more) built in the basic and analytical science fields were selected for this study and their number of construction, amount of construction, year of acquisition, type of institution, and standard classification code were analyzed. Differences of the number and amount of construction with-in and by year of acquisition, standard classification code, and type of institution were tested using a single sample Chi-square test, Mann-Whitney U test, and Kruskal-wallis test. The correlation among the three variables was analyzed by using the Chi-square test of cross-tabulation analysis. And there was a statistically significant correlation among the year of acquisition, standard classification code, and type of institution (p<.05). Compared to the 2000s, in the 2010s, high-priced Optical Electronics/Video Equipment was installed at private universities, private enterprises, and government-affiliated research institute. Therefore, the domestic construction status of Chinese's research facility & equipment in the basic science and analytical science field is less than that of the domestic ones, but the number and the amount of construction are increasing statistically. So it is necessary for the government to be able to recognize the possibility that the Chinese's research facility and equipment can encroach on the domestic research industry market and to prepare related provision.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.815-824
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• 2013

Traditional Pearson chi-squared test is not appropriate for the data collected by the complex sample design. When one uses the traditional Pearson chi-squared test to the complex sample categorical data, it may give wrong test results, and the error may occur not only due to the biased variance estimators but also due to the biased point estimators of cell proportions. In this study, the design based consistent Wald test statistics was derived for k-population homogeneity test, and the traditional Pearson chi-squared test statistics was partitioned into three parts according to the causes of error; the error due to the bias of variance estimator, the error due to the bias of cell proportion estimator, and the unseparated error due to the both bias of variance estimator and bias of cell proportion estimator. An analysis was conducted for empirical results of the relative size of each error component to the Pearson chi-squared test statistics. The second year data from the fourth Korean national health and nutrition examination survey (KNHANES, IV-2) was used for the analysis. The empirical results show that the relative size of error from the bias of variance estimator was relatively larger than the size of error from the bias of cell proportion estimator, but its degrees were different variable by variable.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.17-25
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• 2009

The goal of this study is to develop Logistic regression model by accident location(entry section, exit section, inside intersection and pedestrian crossing section). Based on the accident data of Chungbuk Provincial Police Agency(2004$\sim$2005) and the field survey data, the geometric elements, environmental factor and others related to traffic accidents were analyzed. Developed models are all analyzed to be statistically significant(chi-square p=0.000, Nagelkerke $R^2$=0.363$\sim$0.819). The models show that the common factors of accidents are the traffic volume(ADT), distant of crossing and exclusive left turn lane, and the specific factors are the minor traffic volume(inside intersection model) and U-turn of main road(pedestrian crossing model). Hosmer & Loineshow tests are evaluated to be statistically significant(p$\geqq$0.05) except the entry section model. The correct classification rates are also analyzed to be very predictable(more than 73.9% to all models).