• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.2
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• pp.73-82
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• 2000

본연구의 목적은 반복하중을 받는 철근콘크리트 교량 교각의 비선형 이력거동을 해석적으로 예측하는 것이다 이를 위해서 반복적인 횡하중이 작용하는 경우에 실험결과와 일치하는 교각의 하중-변위 이력곡선을 도출하고자 수정된 trilinar 이력거동모델을 이용하였다 철근과 콘크리트의 비선형 거동특성과 각 하중단계에 따른 교각의 중립축을 구하여 소성힌지부의 모멘트와 변형률을 구하고 반복하중하에서의 강성의 변화를 해석적으로 모형화하기 위하여 각기 다른 강성을 갖는 5가지 지선을 갖춘 형태의 이력거동모델식을 제안하였다 본 연구에서는 실험적으로 구한 하중-변위 이력곡선을 이용하여 축하중비 주철근비 및 구속철근비에 따른 강도감소지수와 강성감소지수의 영향을 회귀분석을 이용하여 일반식으로 제안하였다 새로운 이력거동 해석 모델을 프로그램 SARCF III에 적용함으로써 기존 철근콘크리트 교각에 강도 및 강성감소 현상을 정확하게 예측하였다

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.665-666
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• 2008

본 연구는 학습 성취도 예측을 통한 완전학습 시스템을 연구하는데 그 목적이 있다. 학급 내의 95%의 학생들이 학습 과제의 90% 이상을 완전히 학습해 내는 것이 완전학습이다. 그러나 개인의 수준차로 인한 완전학습 도달 시간이 상이하고, 그 도달 시간을 파악하기가 어려우므로 현실적으로 완전학습에 도달하기란 쉬운 일이 아니다. 본 연구에서는 이러한 현실적인 어려움을 극복하고자 학생들의 과거 현재 학습 성취 데이터를 분석하여, 미래 학습 성취도를 예측함으로써 보충학습이 필요한 학생을 미리 선별하고, 학생별 특성과 수준에 맞는 보충학습 자료 제공을 통한 재학습 유도로 정해진 기간 내에 단계별(단원별, 학기별)로 완전학습에 도달할 수 있도록 하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.126-139
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• 2011

In the traditional four-step travel demand models, each step is sequentially conducted following the model estimation at the previous step. The accuracy of the following model is partly dependent on whether the model at the former stage was properly established or not. Therefore, trip generation, which is the first step in this conventional model, has great effects on the modeling process and forecasting results. Linear regression models for trip generation of Seoul Metropolitan Area might increase the forcasting errors, since a variety of land-use characteristics are not considered. Hence, in this study, zonal factors such as socioeconomic and land use variables are included to improve the elaboration of trip generation. Comparing the %RMSE with the existing models, which contain bigger errors in the zones highly based on the secondary and tertiary industries than residence-based, the trip generation models including those variables seem more appropriate overall.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.3
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• pp.233-243
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• 2008

A tunnel behavior predicted in the investigation and design stage is often different from its actual behavior due to mainly the complexity of ground conditions. In a tunnel construction, therefore, it is necessary to ensure the stability of the tunnel by predicting the behaviors of the ground and the supports through observations and measurements, and modifying immediately excavation and reinforcing methods when necessary. To do so, it is important to be able to predict the final tunnel behavior based on the initial tunnel behavior as early as possible. In this study, the correlations were obtained between the initial and the final convergence by analyzing statistically the convergence measurement data, collected from two domestic road tunnels under construction using NATM. In order to estimate the unknown displacements, occurred during the period between the excavation and the first measurement, two methods were used - one is the method by means of regression analysis using a modified exponential function and the other the method by a simple linear regression analysis using the data measured within the distance from tunnel face equal to the tunnel diameter (D). Finally, the relationships were obtained between the initial and final convergence, including the non-measured displacements estimated from the two different methods, by performing linear regression analyses. The regression analysis results showed that there are clear linear relationships between the initial and final convegence and the difference between the two linear regression equations was not that large for when using the exponential function and the simple linear function to estimate the non-measured displacements.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.137-142
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• 2006

Cost and duration is important factors which directly affect profit therefore must be forecasted correctly to accomplish success of projects. So construction company uses EVMS(Earned Value Management System) to forecast final cost and duration. But previous forecasting model has low accuracy because of its linear forecasting method and can't reflect characteristic of company and project and changes as each progress. This paper presents cost and duration forecasting model using the slope prediction of cost and duration as each progress to reflect the various characteristics of construction industry. EVMS data of 23 road construction projects was used to make up regression analysis equation of slope forecasting model.

• Journal of the Korean Data and Information Science Society
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• v.23 no.6
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• pp.1173-1181
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• 2012

In order to suggest the basic resources of mathematics education to the specialized high school, we investigate the attitude of students about mathematics education. Questionnaires survey was carried on 654 students and we use the statistical analysis such as chi-square test, gamma, generalized linear model, Anova, regression. Several result can be derived from the questionnaire analysis. There are differences between the general and specialized high school students in the interest, pre-learning ability etc. The specialized school students think the usefulness of mathematics more importantly, while the general school students think more closely related to their course.

• Journal of the Korean Data and Information Science Society
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• v.25 no.6
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• pp.1283-1291
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• 2014

In this paper, we propose forward stagewise algorithm when data are very large or coming in batches sequentially over time. In this situation, ordinary boosting algorithm for large scale data and data batch stream may be greedy and have worse performance with class noise situations. To overcome those and apply to large scale data or data batch stream, we modify the forward stagewise algorithm. This algorithm has better results for both large scale data and data batch stream with or without concept drift on simulated data and real data sets than boosting algorithms.

• Fire Science and Engineering
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• v.28 no.2
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• pp.69-75
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• 2014

This study derives the factors which affect the occurrence of arson from statistical data (population, economic, and social factors) by multiple regression analysis. Multiple regression analysis applies to 4 forms of functions, linear functions, semi-log functions, inverse log functions, and dual log functions. Also analysis respectively functions by using the stepwise progress which considered selection and deletion of the independent variable factors by each steps. In order to solve a problem of multiple regression analysis, autocorrelation and multicollinearity, Variance Inflation Factor (VIF) and the Durbin-Watson coefficient were considered. Through the analysis, the optimal model was determined by adjusted Rsquared which means statistical significance used determination, Adjusted R-squared of linear function is scored 0.935 (93.5%), the highest of the 4 forms of function, and so linear function is the optimal model in this study. Then interpretation to the optimal model is conducted. As a result of the analysis, the factors affecting the arson were resulted in lines, the incidence of crime (0.829), the general divorce rate (0.151), the financial autonomy rate (0.149), and the consumer price index (0.099).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.497-502
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• 2020

For the Navy to acquire the desired vessels in time, it is necessary to plan the schedule accurately for warships. On the other hand, until now, there has been only a subjective prediction of the period of warship construction through a survey by a group of experts. No academic studies have been conducted based on actual data. Therefore, this study presents a model for predicting the construction period of a warship through linear regression based on actual data. Experts first identified the factors that can affect the warship construction period. Actual data of the factors were collected, and regression analysis was performed to estimate the ship construction period. As a result, the key factors selected that influence the construction period of a ship were the number of operational test items, number and type of equipment, and the number and type of R&D equipment. The resulting regression model revealed 96.5% accuracy in terms of internal validity.

• Culinary science and hospitality research
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• v.16 no.2
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• pp.49-63
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• 2010

The purpose of this study is to investigate how menu management effect on job efficiency at a hotel restaurant. Target standardization amount is needed to set for effective menu management to give quality menu toward customers to do that bring effective job efficiency. The survey is conducted to employees who are working at hotel restaurant. To verify the hypotheses, set this study up frequency analysis, reliability analysis, factor analysis, and linear regression analysis. The collected questionnaires were analyzed through statistical package SPSS WIN 12.0. Moreover, adjusting regression analysis using multiplying matrix was carried to obtain the results of effectiveness. The results show that menu management is required to apply the target amount of standardization in order to increase the job efficiency. At a menu planning phase, managers are expected to compose menu after having full consultation with employees. During the process, the target standardization amount can play a key role to improve job efficiency. Conclusively, to get effective customer service performance, it is necessary to set the target amount standardization if you are considering a trend and taste of customers who should be kept being adjusted or supplemented in line with a trend.