• Journal of the Korean Data and Information Science Society
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• 제28권6호
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• pp.1511-1520
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• 2017

본 연구는 과학과 전투훈련 자료를 분석하여 작전 및 군사훈련 방법을 향상하고 필요한 군사교리를 검증하기 위한 것이다. 우리는 과학화 전투훈련 중 대대급 공격작전에 대해 개별 전투원이 공격작전간 개인 화기를 이용하여 적을 중상 이상의 전투불능 상태로 만든 인원수를 반응변수로 둔다. 본 연구의 반응변수는 영이 지나치게 많이 관측되어 전통적인 일반화 선형모형에서 분석이 제한된다. 우리는 과대산포 및 영이 과도하게 관측된 점을 고려하여 영과잉 회귀모형과 허들 회귀모형을 자료에 적합하여 분석한다. 우리의 분석 결과는 대한민국 육군의 보병대대와 같은 소부대의 다양한 작전 및 전술적 요인에 대한 분석과 전술제대의 군사교리 검증함에 있어 적절한 참고자료로 활용될 수 있다.

• 응용통계연구
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• 제24권5호
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• pp.951-961
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• 2011

본 논문에서는 제로팽창 음이항(ZINB) 회귀모형에서 회귀계수에 대한 추론방법으로 마코프체인몬테카를로(MC MC) 기법을 이용한 베이지안 추론방법을 제안하였다. 본 연구에서 고려한 ZINB 회귀모형은 반응변수의 평균뿐만 아니라 제로팽창확률에 대한 회귀모형을 고려한 것으로서 Jang, et al.(2010)의 연구를 확장한 것이다. 아울러 실제사례에 본 연구에서 제안한 베이지안 추론방법을 적용하고 과대산포를 허용하지 않는 제로팽창 포아송(ZIP) 회귀모형과 적합결과를 DIC를 이용하여 비교하였다. 실제 사례분석 결과 ZINB 회귀모형의 DIC가 ZIP모형보다 작게 나타나 ZINB 회귀모형이 ZIP 회귀모형보다 잘 적합되었음을 알 수 있었다.

• Journal of Preventive Medicine and Public Health
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• 제31권1호
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• pp.82-90
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• 1998

A large number of studies have indicated associations between particulate air pollution and daily mortality. Daily measurements of total suspended particulates (TSP) by high volume air sampler were matched to daily death counts supplied by the National Statistics Office, Korea. All deaths, except deaths from accidents, occurred at Ulsan from 1 January 1991 to 31 December 1994 were considered in the poisson regression analysis. The multiple regression models were used to investigate a main effects of air particulate pollution controlling for $SO_2$ levels, air temperature, relative humidity, seasonal variation, and calendar year. The results indicated that the effects of TSP, $SO_2$, temperature, and relative humidity were not significantly associated with all cause mortality. It could, however, be emphasized that the size of the parameter estimate of TSP was very similar to that of previous studies. An increase in particulates of $100{\mu}g/m^3$ was associated with a 3% increase in mortality. This relationship was observed at TSP levels well below the current National Ambient Air Quality Standard of $150{\mu}g/m^3$ in Korea as well.

• 한국도로학회논문집
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• 제13권1호
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• pp.13-19
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• 2011

본 연구의 목적은 가로구간 사고특성을 분석하고 주 야간 사고모형을 개발하는데 있다. 이를 위해 청주시 가로구간 24개 도로를 연구대상으로 2007년 사고 자료를 이용한다. 연구의 주요결과는 다음과 같다. 첫째, 가로구간의 주간 사고건수가 야간 사고건수보다 많았지만, 사고율에서는 야간사고율이 높은 것으로 분석되었다. 둘째, 4개의 사고모형이 개발되었으며, 이들은 통계적으로 모두 유의한 것으로 분석되었다. 마지막으로, 모형에 채택된 독립변수를 활용하여 주 야간 사고모형의 차이가 비교 분석되었다.

• 터널과지하공간
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• 제23권3호
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• pp.212-218
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• 2013

풍화된 응회암 시험편을 모사하기 위하여 최고 예열온도를 200, 400, 600($^{\circ}C$)로 한 예열시험편을 제작하였다. 각 예열시험편에 대한 실내시험을 통해 비중, 흡수율, 탄성파속도, 일축압축강도, 압열인장강도, 탄성계수, 포아송비, 슬레이크 내구성 지수를 측정하였다. 암석에 열을 가하는 경우 물성의 열화가 발생하는 것으로 나타났으나 예외적으로 슬레이크 내구성 지수는 별로 영향을 받지 않는 것으로 평가되었다. P-파 속도와 일축압축강도, 압열인장강도, 탄성계수, 흡수율 간에는 상당한 상관성이 있는 것으로 해석되었으며, P-파 속도를 알면 일축압축강도, 압열인장강도, 탄성계수, 흡수율을 추정할 수 있는 회귀식을 도출하였다.

• Journal of Preventive Medicine and Public Health
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• 제54권5호
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• pp.352-359
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• 2021

Objectives: The aim of this study was to examine the geographic distribution of diabetes mortality in Japan and identify socioeconomic factors affecting differences in municipality-specific diabetes mortality. Methods: Diabetes mortality data by year and municipality from 2013 to 2017 were extracted from Japanese Vital Statistics, and the socioeconomic characteristics of municipalities were obtained from government statistics. We calculated the standardized mortality ratio (SMR) of diabetes for each municipality using the empirical Bayes method and represented geographic differences in SMRs in a map of Japan. Multiple linear regression was conducted to identify the socioeconomic factors affecting differences in SMR. Statistically significant socioeconomic factors were further assessed by calculating the relative risk of mortality of quintiles of municipalities classified according to the degree of each socioeconomic factor using Poisson regression analysis. Results: The geographic distribution of diabetes mortality differed by gender. Of the municipality-specific socioeconomic factors, high rates of single-person households and unemployment and a high number of hospital beds were associated with a high SMR for men. High rates of fatherless households and blue-collar workers were associated with a high SMR for women, while high taxable income per-capita income and total population were associated with low SMR for women. Quintile analysis revealed a complex relationship between taxable income and mortality for women. The mortality risk of quintiles with the highest and lowest taxable per-capita income was significantly lower than that of the middle-income quintile. Conclusions: Socioeconomic factors of municipalities in Japan were found to affect geographic differences in diabetes mortality.

• 한국도로학회논문집
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• 제14권6호
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• pp.121-129
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• 2012

PURPOSES : Traffic accidents at intersections have been increased annually so that it is required to examine the causations to reduce the accidents. However, the current existing accident models were developed mainly with non-linear regression models such as Poisson methods. These non-linear regression methods lack to reveal complicated causations for traffic accidents, though they are right choices to study randomness and non-linearity of accidents. Therefore, to reveal the complicated causations of traffic accidents, this study used structural equation methods(SEM). METHODS : SEM used in this study is a statistical technique for estimating causal relations using a combination of statistical data and qualitative causal assumptions. SEM allow exploratory modeling, meaning they are suited to theory development. The method is tested against the obtained measurement data to determine how well the model fits the data. Among the strengths of SEM is the ability to construct latent variables: variables which are not measured directly, but are estimated in the model from several measured variables. This allows the modeler to explicitly capture the unreliability of measurement in the model, which allows the structural relations between latent variables to be accurately estimated. RESULTS : The study results showed that causal factors could be grouped into 3. Factor 1 includes traffic variables, and Factor 2 contains turning traffic variables. Factor 3 consists of other road element variables such as speed limits or signal cycles. CONCLUSIONS : Non-linear regression models can be used to develop accident predictions models. However, they lack to estimate causal factors, because they select only few significant variables to raise the accuracy of the model performance. Compared to the regressions, SEM has merits to estimate causal factors affecting accidents, because it allows the structural relations between latent variables. Therefore, this study used SEM to estimate causal factors affecting accident at urban signalized intersections.

• 산업공학
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• 제15권1호
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• pp.64-72
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• 2002

Broaching machine is widely used for machining inner shaped slots in the work-pieces, and provides vertical motion (usually hydraulically powered) between tool and work-piece. In this study, we modelled the tool life process and investigated economic tool life of broaching machine. Tool life process is divided into wear-process and succeeding failure process. Wear process is defined as machining wear and failure process as 'chipping' occurred by random shock. We modelled wear process as linear regression function for products amounts and assumed failure process as Poisson process. Economic tool life is defined as the number of lots which minimizes average tool related cost per lot and analyzed by using age replacement policy technique. As tool-related cost factors, we consider tool replacement cost, tool maintenance cost and quality costs of products. The results of this study can be applied to analyze life process of general machining tools.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2017년도 추계학술대회
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• pp.27-29
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• 2017

Container terminals in Northern Vietnam have recorded an impressive development in recent years. This development, however, also raises a fierce competition among local container terminals to attract customers. Beside the handling charges, the vessels' waiting cost is also an important factor that drive the opinion of users in choosing appropriate terminal. This research plans to estimate the waiting cost in different container terminals in Northern Vietnam by building regression equation that describe the relationship between the rate of throughput/capacity and waiting cost/TEU. Queuing theory with the application of Poisson distibution is used to estimate the waiting time of arrival vessels and uncertainty theory is applied to estimate the vessel's daily expenses. Previous studies suggested two different formation of the equation and according to the research results, cubic equation is more suitable in the given case. The research results are also useful for further research which require calculation of waiting cost per TEU in each container terminal in Northern Vietnam.

• International Journal of Human Ecology
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• 제14권2호
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• pp.41-51
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• 2013

This study investigated how family capital was associated with the working memory of young school-aged children from immigrant families in the United States using the New Immigrant Survey. Family capital was identified as economic, human, cultural, and social capital, and children's working memory was measured by the Digit Span scores. Poisson regression analysis was used for examining the sample of 428 children from the New Immigrant Survey. Results indicated that cultural capital within the home was positively associated with the working memory of young school-aged children whereas economic, human, and social capital was not. Implications and limitations of the study are also discussed.