• The Korean Journal of Applied Statistics
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• v.27 no.3
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• pp.419-430
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• 2014

An accurate prediction of electricity supply and demand is important for daily life, industrial activities, and national management. In this paper electricity sales is predicted by time series modelling. Real data analysis shows the transfer function model with cooling and heating days as an input time series and a pulse function as an intervention variable outperforms other time series models for the root mean square error and the mean absolute percentage error.

• The Korean Journal of Applied Statistics
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• v.30 no.5
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• pp.719-731
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• 2017

In September 2010, the Korea government increased the speed limit on the Gyeongbu Expressway (Cheonan IC.-Yangjae IC) from 100 to 110 km per hour. This paper considers ARIMA-Intervention model to analyze the effects of the speed limit change on the incidences of traffic accidents and injuries. In addition, in order to investigate the effects more clearly, we also analyze the difference between the two lines of Cheonan IC-Yangjae IC and Busan IC-Cheonan IC. As a result, we observe that the numbers of accidents and injuries have increased after the speed limit change. The increases are strikingly distinctive in comparison to other lines (Busan IC-Cheonan IC) where there have been no changes in the maximum speed limit.

• International Area Studies Review
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• v.13 no.3
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• pp.361-383
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• 2009

This study extends theoretically the expected utility model of trade-conflict developed by Polacheck if a third country is involved, and analyses empirically how trade between North Korea and China affects to the political conflict between South and North Korea. The results of empirical analysis show that North Korea's exports to South Korea and China do not affect the conflict or cooperative relations between South and North Korea. But North Korea's imports from South Korea and China affect to the conflict between South and North Korea: increasing of North Korea's imports to South Korea reduce conflict between South and North Korea, but increasing of North Korea's imports to China increase conflict between South and North Korea.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.4
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• pp.18-26
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• 2015

This study is a fundamental research to suggest a forecasting model for short-term railway passenger demand focusing on major lines (Gyeungbu, Honam, Jeonla, Janghang, Jungang) of Saemaeul rail and Mugunghwa rail. Also the author tried to verify the potential application of the proposed models. For this study, SARIMA model considering characteristics of seasonal trip is basically used, and daily mean forecasting models are independently constructed depending on weekday/weekend in order to consider characteristics of weekday/weekend trip and a legal holiday trip. Furthermore, intervention events having an impact on using the train such as introduction of new lines or EXPO are reflected in the model to increase reliability of the model. Finally, proposed models are confirmed to have high accuracy and reliability by verifying predictability of models. The proposed models of this research will be expected to utilize for establishing a plan for short-term operation of lines.

• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.222-233
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• 2010

This paper aims at predicting the BDI from Jan. to Dec. 2010 using such econometric techniues of the univariate time series as stochastic ARIMA-type models and Hodrick-Prescott filtering technique. The multivariate cause-effect econometric model is not employed for not assuring a higher degree of forecasting accuracy than the univariate variable model. Such a cause-effect econometric model also fails in adjusting itself for the post-sample. This article introduces the two ARIMA models and five Intervention-ARIMA models. The monthly data cover the period January 2000 through December 2009. The out-of-sample forecasting performance is compared between the ARIMA-type models and the random walk model. Forecasting performance is measured by three summary statistics: root mean squared error (RMSE), mean absolute error (MAE) and mean error (ME). The RMSE and MAE indicate that the ARIMA-type models outperform the random walk model And the mean errors for all models are small in magnitude relative to the MAE's, indicating that all models don't have a tendency of overpredicting or underpredicting systematically in forecasting. The pessimistic ex-ante forecasts are expected to be 2,820 at the end of 2010 compared with the optimistic forecasts of 4,230.

• Korean Journal of Health Psychology
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• v.16 no.3
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• pp.609-622
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• 2011

The purpose of this study is to investigate the causality between life satisfaction and domain satisfactions. For this study, data were collected from 207 respondents. They completed World Health Organization Quality of Life Assessment Instrument - Brief (WHOQOL-BREF) which is self-report questionnaire asking about life satisfaction and domain satisfactions. For data analysis, the verification procedure by autoregressive crosslagged modeling of structural equation was used. The analysis results of measures showed the causal relation between the two variables, that is, domain satisfactions acted as cause of life satisfaction. There were discussions on the issues about the analysis method of the autoregressive crosslagged modeling, the implications of the results, and the limits of the research. This study ascertained the intervention direction between life satisfaction and domain satisfactions to promote life satisfaction.

• 한국노년학
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• v.37 no.1
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• pp.173-200
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• 2017

This study is designed to verify the actual effect on the prevention of the elderly suicide of the integrated crisis intervention service which has been widely provided across all local communities in Gyeonggi-province focusing on the integrated crisis intervention model developed for the prevention of elderly suicide. The integrated crisis intervention model for the local communities and its manual were developed for the prevention of elderly suicide by integrating the crisis intervention theory which contains local community's integrated system approach and the stress vulnerability theory. For the analysis of the effect, the geriatric depression and suicidal ideation scale was adopted and the data was collected as follows; The data was collected from 258 people in the first preliminary test. Then, it was collected from the secondary test of 184 people after the integrated crisis intervention service was performed for 6 months. The third collection of data was made from 124 people after 2 or 3 years later using the backward tracing method. As for the analysis, the researcher used the R Statistics computing to conduct the test equating, and the vertical scaling between measuring points. Then, the researcher conducted descriptive statistics analysis and univariate analysis of variance, and performed multi-level modeling analysis using Bayesian estimation. As a result of the study, it was found out that the integrated crisis intervention model which has been developed for the elderly suicide prevention has a statistically significant effect on the reduction of elderly suicide in terms of elderly depression and suicide ideation in the follow-up measurement after the implementation of crisis intervention rather than in the first preliminary scores. The integrated crisis intervention model for the prevention of elderly suicide was found to be effective to the extent of 0.56 for the reduction of depression and 0.39 for the reduction of suicidal ideation. However, it was found out in the backward tracing test conducted 2-3 years after the first crisis intervention that the improved values returned to its original state, thus showing that the effect of the intervention is not maintained for long. Multilevel analysis was conducted to find out the factors such as the service type(professional counseling, medication, peer counseling), characteristics of the client (sex, age), the characteristics of the counselor(age, career, major) and the interaction between the characteristics of the counselor and intervention which affect depression and suicidal ideation. It was found that only medication can significantly reduce suicidal ideation and that if the counselor's major is counseling, it significantly further reduces suicidal ideation by interacting with professional counseling. Furthermore, as the characteristics of the suicide prevention experts are found to regulate the intervention effect on elderly suicide prevention in applying integrated crisis intervention model, the primary consideration should be given to the counseling ability of these experts.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1517-1521
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• 2007

현재 우리나라의 경우는 국가하천이나 주요 지방하천에 대해서는 환경부 등 지방자치단체에서 측정망을 통해서 꾸준히 수질자료가 축적되고 있으나 농촌유역의 소하천 수질개선 사업을 위해 필요한 수질관련 자료는 거의 없다. 최근에 와서 수질 정보 시스템의 개발 및 수질 오염 모니터링을 위한 측정망의 확충 등과 같은 관리체계의 개선에 대한 노력이 활발히 진행되고 있으나 이에 소요되는 재원문제 등으로 채취빈도나 분석항목이 크게 미흡하다. 특히 조사가 유역이 크고 복잡한 복합유역을 대상으로 하기 때문에 자연히 오염물질 유출에 미치는 변수가 너무 많이 개입되므로 해석자체가 특정유역에 제한되기 마련이다. 따라서 본 과업에서는 농촌 소하천 유역을 대상으로 실측 수질-유량 상관분석을 통한 수문모형을 구축하였고 국립환경과학원에서 수계오염총량관리기술지침(2004)에서 제시한 토지계의 발생부하 원단위를 이용하여 SWAT 모형을 보정하였다. 보정된 모형을 이용하여 소유역별 1년(12개월) 오염물질 부하량 및 강우유출량을 산정하였으며, 현장실측을 통해 산정된 유달부하량과 모의 부하량과의 비를 이용한 유달율을 산정하였다.

• Korean Journal of Social Welfare
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• v.64 no.1
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• pp.79-100
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• 2012

The predominant concern of the study consist in: (1) the direct effect of social commitment on teachers' intervention efficacy for helping both victims and offenders in school violence situation; (2) the indirect effects of both teachers' perceptions of offenders and victims, and fairness of school regulations on teachers' intervention efficacy. Research is based on a survey conducted with 351 teachers(84 males and 267 females) from 10 middle schools located in different districts of the city of Daegu. In order for subjects to verify research questions, structural equation models in teachers' intervention efficacy for helping both victims and offenders were explored. In order to verify the difference between mediators' effect, along with total indirect effect and each individual mediator's effects, bias-corrected bootstrapping analysis by using Mplus were employed. The major findings of the study supported the significance on direct effect of social commitment, and indirect effect of both fairness of school regulations and teachers' perceptions toward offenders and victims, on teachers' intervention efficacy. However, the indirect effect of fairness of school regulations(.025) was far outweighed by teachers' perceptions(.224) toward offenders and victims. In conclusion, the above findings claim our attention in that they provide a range of practical implications for teachers and other related professionals including school workers who are engaged in helping out both victims and offenders in school violence situation.

• Journal of the Korean Data and Information Science Society
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• v.27 no.3
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• pp.725-732
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• 2016

This study analyzes the number of Jeju-bound tourists according to travellers' purposes. We classify the travellers' purposes into three categories: "Rest and Sightseeing", "Leisure and Sport", and "Conference and Business". To see an impact of MERS outbreak occurred in May 2015 on the number of tourists, we fit seasonal ARIMA-Intervention model to the monthly arrivals data from January 2005 to March 2016. The estimation results show that the number of tourists for "Leisure and Sport" and "Conference and Business" were significantly affected by MERS outbreak whereas arrivals for "Rest and Sightseeing" were little influenced. Using the fitted models, we predict the number of Jeju-bound tourists.