• 대기
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• 제34권2호
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• pp.177-185
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• 2024

As increasing global interest in renewable energy due to the ongoing climate crisis, there is a growing need for efficient technologies to manage such resources. This study focuses on the predictive skill of daily solar power generation using weather observation and forecast data. Meteorological data from the Korea Meteorological Administration and solar power generation data from the Korea Power Exchange were utilized for the period from January 2017 to May 2023, considering both inland (Daejeon) and coastal (Busan) regions. Temperature, wind speed, relative humidity, and precipitation were selected as relevant meteorological variables for solar power prediction. All data was preprocessed by removing their systematic components to use only their residuals and the residual of solar data were further processed with weighted adjustments for homoscedasticity. Four models, MLR (Multiple Linear Regression), RF (Random Forest), DNN (Deep Neural Network), and RNN (Recurrent Neural Network), were employed for solar power prediction and their performances were evaluated based on predicted values utilizing observed meteorological data (used as a reference), 1-day-ahead forecast data (referred to as fore1), and 2-day-ahead forecast data (fore2). DNN-based prediction model exhibits superior performance in both regions, with RNN performing the least effectively. However, MLR and RF demonstrate competitive performance comparable to DNN. The disparities in the performance of the four different models are less pronounced than anticipated, underscoring the pivotal role of fitting models using residuals. This emphasizes that the utilized preprocessing approach, specifically leveraging residuals, is poised to play a crucial role in the future of solar power generation forecasting.

• 한국시스템다이내믹스연구
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• 제15권3호
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• pp.37-59
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• 2014

This paper is to study dynamics of populations of religions. As human population is a crucial source of social dynamics, the religious population is a driving force that changes political and cultural landscape of society. Although many christian scholars have reported important causal factors in changing population of christian world, there are few studies on the dynamics of religious population in system dynamics. This paper interprets these dynamic mechanisms in terms of feedback loops and constructs a basic system dynamic model to forecast future trend of religious population in Korean society.

• 기술사
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• 제37권4호
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• pp.55-59
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• 2004

Exploitation of the ocean's deep water has brought humanity a wealth of treasures for centuries. Even so, it can confidently be forecast that the Ocean will be far more important to future generations than it has ever been in the past. Although many researchers endeavor to explore oceans, the ocean holds the crucial elements for maintaining a growing industrialized population in search of raw materials. This requires careful study and selection of innovations that will provide future generations and raw materials with an unlimited renewable and non-pollution energy and raw materials source with advantageous side benefits.

• Asia pacific journal of information systems
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• 제9권1호
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• pp.1-16
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• 1999

There is a controversy over the necessity of information intermediaries in virtual market. This study tried to suggest several reasons why they would still flourish in virtual market. It also tried to find out their roles and to forecast their role changes in the future on the basis of Delphi analysis. Though an exploratory study, this can shed some lights on the future studies related to information intermediaries and virtual market.

• 산업경영시스템학회지
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• 제13권21호
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• pp.11-18
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• 1990

Because of the descent trend of the recent oil price and the ascent elements of the manufacturing price of public coal. the future demand of public coal is very obscured. In this paper, forecast the public coal demand by the regression analysis method reflected the policy and economic index of alternative energies.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2005년도 춘계학술대회 논문집
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• pp.479-485
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• 2005

최근 RFID 기술의 급속한 확산은 기존 인식매체의 한계를 극복하고, 기업 및 산업 전반에 새로운 혁신을 가져올 것으로 예상된다. 특히 항만물류산업의 경우 RFID 기술이 적용될 경우 많은 파급효과를 가져올 것으로 예상된다. 우리나라에서는 정부의 각종 시범사업을 통해 RFID 기술을 항만물류산업에 도입하고 있으나 현실적인 개선과제 및 기술도입 전략 등에 대한 연구 부족 등으로 많은 어려움을 겪고 있다. 본 연구에서는 기존 문헌 조사와 현업 설문 분석을 통해 단위 업무별 RFID 기술도입을 위한 우선순위를 선정하여 기술도입을 위한 로드맵을 제시하고자 한다. 향후 본 연구는 항만물류산업의 RFID 기술도입에 성공적인 가이드라인이 될 것이라 기대된다.

• 암석학회지
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• 제27권1호
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• pp.49-66
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• 2018

화산위험지도 작성은 1960년대 과학 탐구의 초점이 되었다. Dwight Crandell과 Don Mullineau는 '과거는 미래의 열쇠이다'라는 관점으로 재해위험 매핑에 대한 지질학적 접근 방법을 개척했다. 세인트 헬렌즈산의 위험도 평가와 가까운 미래의 분출 예측에 대한 1978년 발간물, 그리고 1980년 대규모 분화로 화산위험 평가의 유용성이 입증되었고 화산 과학의 이 영역에서 거대한 성장이 시작되었다. 1980년대의 위험한 지역을 식별하기 위해 위험지역 이해 프로세스의 수치 모델을 개발하고 사용하기 시작했으며, 1990년대 후반부터 확산되었다. 수치모의 모델 산출물은 화산의 지질학적 지식에 의해 강조될 때 가장 유용하고 정확하다. 화산위험지도는 장기간의 무조건적인 화산 재해 위험을 묘사하는지, 어느 정도의 위험을 가진 모든 지역을 보여주는지, 화산이 불안정 또는 분화 위기 시에 개발되어 현재의 감시, 관찰 및 예보 정보를 고려한 지도로 크게 분류할 수 있다.

• 유통과학연구
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• 제17권10호
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• pp.41-48
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• 2019

Purpose - This study investigates whether financial analysts consider the intangible investment implicit in selling, general, and administrative (SG&A) expenditures to forecast firms' future earnings. Research design, data, and methodology - Using 52,609 U.S. firm-year observations spanning 1984-2016, this study examines the association between the Intangible investment implicit in SG&A expenditures and properties of analysts' earnings forecasts. To estimate the Intangible investment of SG&A, I decompose SG&A excluding R&D and advertising expenditures into maintenance and investment components following Enache and Srivastava (2017). Results - The main results show that analysts' earnings forecast errors and dispersion in analysts' forecasts increase with the intangible investment derived from SG&A because the investment component of SG&A affects future earnings and the uncertainty of those earnings. However, these results are weakened in the wholesale and retail industries where firms have a higher level of investment component of SG&A. I attribute the weaker results to low R&D expenditures in those industries. Conclusion - This study indicates that financial analysts incorporate the intangible investment of SG&A into their earnings forecasts differently across firms and industries. Furthermore, this study supports the argument for the separate reporting of the investment nature of SG&A from other operating expenses such as maintenance nature of SG&A.

• 응용통계연구
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• 제28권3호
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• pp.467-475
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• 2015

정확한 수요예측은 수입관리(RM)에서 중요한 요소이다. 기 출발편 예약 데이터는 미래 출발편의 수요를 예측하는데 이용되는데, 이 중 일부 데이터에는 예약 요청이 거부된 경우가 포함된다. 거부된 예약 요청은 통계학적 관점에서 중도절단된 것으로 해석될 수 있으며, 이러한 중도절단된 수요를 복원하는 것은 미래 출발편의 참수요 예측을 위해 중요한 사안이다. 현재까지 여러 복원방법들이 소개되었으며, Expectation Maximization 방법이 가장 우수하다고 알려져있다. 본 연구에서는 중도절단된 자료를 복원할 수 있는 회귀모형 기반의 새로운 수요복원 방법을 제시하였다. 그리고 모의실험을 통해 제안된 새로운 방법의 성능을 RM에서 대표적으로 사용되는 두 가지 복원방법들과 비교하였다.

• 한국항해항만학회지
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• 제35권4호
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• pp.343-349
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• 2011

The forecasting of container volume which is the basis of port logistics facilities expansion has a great influence on development of an port. Based on this importance, various previous studies have presented methodology on container volume forecasting. The results of many previous studies pointed out the limitations of future forecasting based on past container volume and emphasized that more various factors should be considered to compensate this. Taking notice of this point, this study forecasted future container volume by using ARIMA model, time series analysis and System Dynamics (SD) method, a dynamic analysis technique and performed the comparative review with the forecast of the Ministry of Land, Transport and Maritime affairs. Recently with rapid changes in economic and social environment, the non-linear change tendency for forecasting container traffic is presented as a new alternative to the country.