• Journal of the Korean Society for information Management
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• v.22 no.3 s.57
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• pp.213-232
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• 2005

The purpose of this study is to determine factors affecting text difficulty and to model objective formulas which measure readability scores. Some readability-related factors such as total number of letters, total number of syllables, total number of unique syllables, total number of sentences and total number of paragraphs were found through correlation analysis. Some regression equations with these factors as their variables were produced through regression analysis. A model estimating readability score from total number of unique syllables was a good formula, while a model with two factors, total number of unique syllables and new syllable occurrence ratio, was a better enhanced one. The readability score represents detailed level so we can recommend students read texts corresponding to their reading levels.

• Proceedings of the KOR-KST Conference
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• 2007.11a
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• pp.315-322
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• 2007

신호교차로 교통사고는 90년대 이후 도시가 발달하고 산업이 고도화됨에 따라 교통 혼잡 문제와 함께 심각한 사회문제로 대두되고 있다. 특히 신호교차로의 교통사고는 인적요인, 차량요인, 환경적 요인 등이 복합적으로 작용하여 발생하는데, 교통량의 집중과 도로의 기하구조, 운전자 과실 등이 교통사고의 주요 인자로 작용하고 있다. 본 연구에서 교통사고 예측모형을 개발하기 위해서 2003년부터 2006년도까지 실제 경기도의 신호교차로에서 발생한 교통사고자료를 기초로 하였다. 구체적으로는 시내가 아닌 지방부 성격을 지닌 일반국도를 대상으로 하였다. 지방부 일반국도의 신호교차로 교통사고 분석에 단순통계분석과 다중회귀분석을 사용하였다. 사고와 관계가 높은 신호주기, 방향별 접근 교통량, 회전교통량 둥과 같은 도로, 교통, 운영조건들로 변수를 정하여 교통사고 예측모형을 도출하였다. 본 연구에서는 도로조건, 교통조건, 운영조건들과 사고와의 관계를 이용하여 경기도 일반국도의 신호교차로 교통사고예측모형을 개발하였고, 이는 지방부 성격을 지닌 교차로에 적용이 가능하다고 판단된다.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.133-138
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• 2001

Increased base cation loss and Al mobilization, a consequence of soil acid neutralization responses, are common in air polluted areas showing forest decline. The prediction models of acid neutralization responses were developed by using indicators of soil acidification level(pH, and base saturation) in order to assess the forest soil sensitivity to acidification. The soil acidification level was greatest in Namsan followed by Kanghwa, Ulsan, and Hongcheon, being contrary to regional total $ANC_H$ pattern through soil columns leached with additional acid ($16.7mmol_c\;H^+/kg$), Both base exchange and Al dissolution were main acid neutralization processes in all study regions. There were low base exchange and high Al dissolution in the regions of the low total $ANC_H$. The $ANC_M$ by sulfate adsorption was greatest in Hongcheon compared with other regions even though the AN rate was very low as 6.4%. Coefficients of adjusted determination of simple and multiple regression models between soil acidification level indicators and the acid neutralization responses were more than 0.52(p<0.04) and 0.89(p<0.01), respectively. The result suggests that soil pH and base saturation are available indicators for predicting the acid neutralization responses. These prediction models could be used as an useful method to measure forest soil sensitivity to acidification.

• The Korean Journal of Applied Statistics
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• v.31 no.2
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• pp.217-228
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• 2018

Since the real estate reporting system was first introduced, about 2 million real estate transaction per year have been reported over the last 10 years with an increasing demand for real estate price estimates. This study looks at the applicability and superiority of the regression-kriging method to derive effective real transaction prices estimation on the location where information about real transaction is unavailable. Several issues on predicting the real estate price are discussed and illustrated using the real transaction reports of Jinju, Gyeongsangnam-do. Results have been compared with a simple regression model in terms of the mean absolute error and root square error. It turns out that the regression-kriging model provides a more effective estimation of land price compared to the simple regression model. The regression-kriging method adequately reflects the spatial structure of the term that is not explained by other characteristic variables.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.1-10
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• 2013

This study was conducted to investigate that bus information was used as an information of travel speed. To determine the travel speed on the road, bus information and the information collected from the point detector and the interval detection installed were compared. If bus information has the function of traffic information detector, can provide the travel speed information to road users. To this end, the model of recognizing the traffic patterns is necessary. This study used simple moving-average method, simple exponential smoothing method, Double moving average method, Double exponential smoothing method, ARIMA(Autoregressive integrated moving average model) as the existing methods rather than new approach methods. This study suggested the possibility to replace bus information system into other information collection system.

• Journal of the Korean Data and Information Science Society
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• v.28 no.3
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• pp.617-624
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• 2017

The production of cabbage, which is mainly cultivated in open field, varies greatly depending on weather conditions, and the price fluctuation is largely due to the presence of a substitute crop. Previous studies predicted the production of cabbage using actual weather data, but in this study, we predicted the wholesale price using unstructured agricultural meteorological data on the web. From January 2009 to October 2016, we collected documents including the cabbage on the portal site, and extracted keywords related to weather in the collected documents. We compared the forecast wholesale prices of simple models and unstructured agricultural weather models at the time of shipment. The simple model is AR model using only wholesale price, and the unstructured agricultural weather model is AR model using unstructured agricultural weather data additionally. As a result, the performance of unstructured agricultural weather model was has been found to be more accurate prediction ability.

• Communications for Statistical Applications and Methods
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• v.18 no.1
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• pp.23-34
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• 2011

Property auctions have become a new method for real estate investment because the property auction market grows in tandem with the growth of the real estate market. This study focused on the statistical model for predicting bid price rates which is the main index for participants in the real estate auction market. For estimating the monthly bid price rate, we proposed a new method to make up for the mean of regions and terms as well as to reduce the prediction error using a decision tree analysis. We also proposed a linear regression model to predict a bid price rate for individual auction property. We applied the proposed model to apartment auction property and tried to predict the bid price rate as well as categorize individual auction property into an auction grade.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.81-90
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• 2009

The safety management of a road network comprises four basic inter-related components：identification of sites(black spot) requiring safety investigation, diagnosis of safety problems, selection of feasible treatments for potential treatment candidates, and prioritization of treatments given limited budgets(Persaud, 2001). Identification process of selecting black spot is very important for efficient investigation of sites. In this study, the accident prediction model for EB method was developed by using accident data and geometric conditions of black spots selected from four-leg signalized intersections in In-cheon City for three years (2004-2006). In addition, by comparing the rank nomination technique using EB method to that by using accident counts, we managed to show the problems which the existing method have and the necessity for developing rational prediction model. As a result, in terms of total number of accidents, both the counts predicted by existing non-linear regression model and that by EB method have high good of fitness, but EB method, considering both the accident counts by sites and total number of accident, has better good of fitness than non-linear poison model. According to the result of the comparison of ranks nominated for treatment between two methods, the rank for treatment of almost sites does not change but SeoHae intersection and a few other intersections have significant changes in their rank. This shows that, with the technique proposed in the study, the RTM problem caused by using real accident counts can be overcome.

• KDI Journal of Economic Policy
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• v.21 no.3_4
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• pp.63-104
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• 1999

본 연구는 외환위기 발생 이후 취해진 고금리정책이 이후의 환율안정에 기여하였는가를 살펴보고 있다. 완전 변동환율제도로 이행된 1997년 12월 이후의 일별자료를 대상으로 표준적인 시계열모형을 사용하여 분석한 주요 결과는 금리상승이 환율의 평가절상을 유도하였다는 것이다. 축약형모형(reduced form regression)에서 나타난 환율의 금리에 대한 탄력성은, 부도율과 같은 위험(risk)변수를 통제한 단순회귀방정식뿐 아니라 VAR모형에서도 1을 소폭 상회하는 정도의 추정치를 얻을 수 있었다. 이러한 결과는 비록 외환위기 이후 환율안정화의 가장 큰 원동력이 외환유동성의 회복이었음에도 불구하고, 외환유동성이 회복될 때까지 단기적으로는 고금리정책이 환율안정화를 위하여 부분적으로 기여하였음을 시사한다고 할 수 있을 것이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.349-356
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• 2021

Since the 1960s, traffic infrastructure, such as bridges, has increased rapidly in Korea as urbanization and industrialization progressed due to economic growth. As the scale of the bridge becomes larger, stability analysis of the superstructure of the bridge is being conducted actively, but scour stability analysis for the substructure of the bridge has not been conducted sufficiently. This study is a basic investigation to prevent large-scale disasters caused by scouring in bridge piers. A simple linear regression model was used to analyze the scour depth calculated through seventeen scour depth calculation formulae, and the scour depth measured through hydraulic model experiments. As a result, the Coleman (1971) formula was the best method among the scour depth calculation formulae, and the Froehlich (1987) formula was the most effective method for calculating the scour depth. In addition, a review using a simple regression model confirmed that the scour depth calculation formulae of CSU (1993), Coleman (1971), and Froehlich (1987) can predict a similar scour depth by reflecting domestic stream characteristics. This study can calculate the scour depth reflecting the environmental conditions of Korea in future stream design.