• 제어로봇시스템학회논문지
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• 제12권7호
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• pp.631-636
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• 2006

In this paper, an algorithm of time series function forecasting using GMDH(group method of data handling) algorithm that gives more weight to the recent data is proposed. Traditional methods of GMDH forecasting gives same weights to the old and recent data, but by the point of view that the recent data is more important than the old data to forecast the future, an algorithm that makes the recent data contribute more to training is proposed for more accurate forecasting. The average error rate of electric power demand forecasting by the traditional GMDH algorithm which does not use data weighting algorithm is 0.9862 %, but as the result of applying the data weighting GMDH algorithm proposed in this paper to electric power forecasting demand the average error rate by the algorithm which uses data weighting algorithm and chooses the best data weighting rate is 0.688 %. Accordingly in forecasting the electric power demand by GMDH the proposed method can acquire the reduced error rate of 30.2 % compared to the traditional method.

• 한국대기환경학회지
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• 제28권3호
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• pp.261-272
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• 2012

In this study, climate variability was predicted by the Weather Research and Forecasting (WRF) model under two different scenarios (current trends scenario; SC1 and managed scenario; SC2) for future urban growth over the Seoul metropolitan area (SMA). We used the urban growth model, SLEUTH (Slope, Land-use, Excluded, Urban, Transportation, Hill-Shade) to predict the future urban growth in SMA. As a result, the difference of urban ratio between two scenarios was the maximum up to 2.2% during 50 years (2000~2050). Also, the results of SLEUTH like this were adjusted in the Weather Research and Forecasting (WRF) model to analysis the difference of the future climate for the future urbanization effect. By scenarios of urban growth, we knew that the significant differences of surface temperature with a maximum of about 4 K and PBL height with a maximum of about 200 m appeared locally in newly urbanized area. However, wind speeds are not sensitive for the future urban growth in SMA. These results show that we need to consider the future land-use changes or future urban extension in the study for the prediction of future climate changes.

• 산업경영시스템학회지
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• 제20권44호
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• pp.243-255
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• 1997

Forecasting the future values of an observed time series is an important problem in many areas, including economics, traffic engineering, production planning, sales forecasting, and stock control. The purpose of this paper is aimed to discover the more efficient forecasting model through the parameter estimation and residual analysis among the quantitative method such as Winters' exponential smoothing model, Box-Jenkins' model, and Kalman filtering model. The mean of the time series is assumed to be a linear combination of known functions. For a parameter estimation and residual analysis, Winters', Box-Jenkins' model use Statgrap and Timeslab software, and Kalman filtering utilizes Fortran language. Therefore, this paper can be used in real fields to obtain the most effective forecasting model.

• 물과 미래
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• 제26권4호
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• pp.117-125
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• 1993

A flood -flow management system model of river basin has been developed in this study. The system model consists of the observation and telemetering system, the rainfall forecasting and data-bank system, the flood runoff simulation system, the dam operation simulation system, the flood forecasting simulation system and the flood warning system. The Multivariate model(MV) and Meterological-factor regression model(FR) for rainfall forecasting and the Streamflow synthesis and reservoir regulation(SSARR) model for flood runoff simulation have been adopted for the development of a new system model for flood-flow management. These models are calibrated to determine the optimal parameters on the basis of observed rainfall, streamflow and other hydrological data during the past flood periods. The flood-flow management system model with SSARR model(FFMM-SR,FFMM-SR(FR) and FFMM-SR(MV)), in which the integrated operation of dams and rainfall forecasting in the basin are considered, is then suggested and applied for flood-flow management and forecasting. The results of the simulations done at the base stations are analysed and were found to be more accurate and effective in the FFMM-SR and FFMM0-SR(MV).

• 한국조사연구학회:학술대회논문집
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• 한국조사연구학회 2000년도 춘계학술대회 조사연구의 방법론적 쟁점
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• pp.15-34
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• 2000

지난 4월 13일에 실시된 16대 총선에서 방송사와 조사기관들이 공동으로 조사하여 발표한 선거예측조사에서 많은 오류가 발생하여 선거예측에 대한 신뢰성에 큰 타격을 받았다. 이에 향후 선거예측조사의 신뢰성을 회복하고 보다 정확한 예측을 위해 기 발표된 예측조사내용을 다각도로 심층분석하여 조사의 오류가 발생한 원인을 살펴보고 이들 오류를 줄이는 방안들을 제시하였다. 아울러 이번에 처음으로 실시된 출구조사에 대한 문제점과 개선안도 함께 살펴보았다.

• 한국시스템다이내믹스연구
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• 제10권1호
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• pp.61-76
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• 2009

We try to use system dynamics to forecast the demand/supply and price, also transportation fare for iron ore. Iron ore is very important mineral resource for industrial production. The structure for this system dynamics shows non-linear pattern and we anticipated the system dynamic method will catch this non-linear reality better than the regression analysis. Our model is calibrated and tested for the past 6 year monthly data (2003-2008) and used for next 6 year monthly data(2008-2013) forecasting. The test results show that our system dynamics approach fits the real data with higher accuracy than the regression one. And we have run the simulations for scenarios made by possible future changes in demand or supply and fare related variables. This simulations imply some meaningful price and fare change patterns.

• 한국안전학회지
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• 제32권3호
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• pp.83-89
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• 2017

A new technology has provided the nation, industry, society, and people with innovative and useful functions. National economy and society has been improved through this technology innovation. Despite the benefit of technology innovation, however, since technology society was sufficiently mature, the unintended side effect and negative impact of new technology on society and human beings has been highlighted. Thus, it is important to investigate a risk of new technology for the future society. Recently, the risks of the new technology are being suggested through a large amount of social data such as news articles and report contents. These data can be used as effective sources for quantitatively and systematically forecasting social risks of new technology. In this respect, this paper aims to propose a data-driven process for forecasting and assessing social risks of future new technology using the text mining, 4M(Man, Machine, Media, and Management) framework, and analytic hierarchy process (AHP). First, social risk factors are forecasted based on social risk keywords extracted by the text mining of documents containing social risk information of new technology. Second, the social risk keywords are classified into the 4M causes to identify the degree of risk causes. Finally, the AHP is applied to assess impact of social risk factors and 4M causes based on social risk keywords. The proposed approach is helpful for technology engineers, safety managers, and policy makers to consider social risks of new technology and their impact.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1996년도 추계학술대회발표논문집; 고려대학교, 서울; 26 Oct. 1996
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• pp.139-145
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• 1996

소봉제품에 대한 시장생산 모형을 만들기 위하여 과거 자료에서 마련된 수량화된 기초 자료를 통계적으로 분석하고 미래의 생산량을 예측하였다. 출고량에 의한 기초 자료의 통계분석 결과에서 여러 가지 계량적 시계열 분석 방법들 중 STEPAR 방법에 의한 예측 방법이 가장 우수한 것으로 나타났다. 통계분석의 결과로 나타난 출고량에 대한 예측값은 생산량을 결정하는 데 있어서 매우 중요한 정보이다. 각 소봉제품들에 대해서 미래의 생산량에 대한 예측값을 STEPAR 방법에 의하여 얻었다. 이 예측값들의 95% 신뢰 구간의 폭이 상당히 넓게 나왔다. 이를 개선하기 위하여 체계적인 데이터 베이스 시스템을 구축하고, 수요-생산-재고의 종합적인 관리를 하며, 이를 뒷받침하기 위한 통합 전산 시스템을 구축해야 할것이다.

• 한국위성정보통신학회논문지
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• 제9권4호
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• pp.53-56
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• 2014

위성시스템설계에서는 설계과정이 초기 설계부터 위성발사까지 약 5년 정도 소요되며, 방송위성수명은 15년 이상까지 될 수 있다. 지구의 온난화 현상은 장기적으로 지구상의 강우율을 점점 증가시키는 추세이다. 이러한 강우율 변화를 포용하기 위해서는 위성링크 설계단계에서 20년 후의 강우감쇠까지 고려하여야 한다. 이 논문에서는 위성방송서비스를 위한 미래의 강우율을 고려하기 위해서 예측용 시계열 시스템 모델을 연구하였다. 이 연구를 통하여 미래 20년 동안의 강우율은 지속적으로 증가할 수 있다는 것을 밝혔다.

• 산학경영연구
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• 제4권
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• pp.281-295
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• 1991

Nothing is more incorrect than forecasting. Nevertheless, forecasting is one of the most important business activities for the effective management. There has been rapid changes of the growth rate in every respect of the Korean hospitaity industry, especially the hotel industry, before and after the 88 Olympic Games. Therefore, the hoteliers shall be in need of more-than-ever accourate demand forecasting for the more systematic management and control. Under the above circumstances, this study suggested the best forecasting technique and method for the better sales and operations of the hotel rooms. The number of rooms sold is selected as a dependent variable of this study which is regarded as the best representative factor of measuring the growth rate of the rooms division performance of the hotels. The first step was to select the most verifiable independent variable diferently from the other countries or other areas of Korea. As a result, the number of foreign visitors was chosen. Empirical research, i.e. correlation and multiple regression analysis, shows that this independent variable has a strong relationship with the dependent variable told above. The second procedure was to estimate the number of rooms will be sold in 1991 on the basis of the formula calculated through the multiple regression analysis. Time series technique was conducted using the data of the number of foreign visitors by purpose of travel from 1987 to 1990. For the more correct forecasting, however, it would be desirable to adopt the data from 1989 considering the product or the industry life cycle. In addition, deeper analysis for the monthly or seasonal forecasting method is needed as a future research.