151 results
Search Results
2. Predicting Energy Generation in Large Wind Farms: A Data-Driven Study with Open Data and Machine Learning.
- Author
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Paula, Matheus, Casaca, Wallace, Colnago, Marilaine, da Silva, José R., Oliveira, Kleber, Dias, Mauricio A., and Negri, Rogério
- Subjects
WIND power plants ,MACHINE learning ,WIND power ,ARTIFICIAL intelligence ,WIND forecasting ,RANDOM forest algorithms ,WIND speed - Abstract
Wind energy has become a trend in Brazil, particularly in the northeastern region of the country. Despite its advantages, wind power generation has been hindered by the high volatility of exogenous factors, such as weather, temperature, and air humidity, making long-term forecasting a highly challenging task. Another issue is the need for reliable solutions, especially for large-scale wind farms, as this involves integrating specific optimization tools and restricted-access datasets collected locally at the power plants. Therefore, in this paper, the problem of forecasting the energy generated at the Praia Formosa wind farm, an eco-friendly park located in the state of Ceará, Brazil, which produces around 7% of the state's electricity, was addressed. To proceed with our data-driven analysis, publicly available data were collected from multiple Brazilian official sources, combining them into a unified database to perform exploratory data analysis and predictive modeling. Specifically, three machine-learning-based approaches were applied: Extreme Gradient Boosting, Random Forest, and Long Short-Term Memory Network, as well as feature-engineering strategies to enhance the precision of the machine intelligence models, including creating artificial features and tuning the hyperparameters. Our findings revealed that all implemented models successfully captured the energy-generation trends, patterns, and seasonality from the complex wind data. However, it was found that the LSTM-based model consistently outperformed the others, achieving a promising global MAPE of 4.55%, highlighting its accuracy in long-term wind energy forecasting. Temperature, relative humidity, and wind speed were identified as the key factors influencing electricity production, with peak generation typically occurring from August to November. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. A Machine Learning-Based Ensemble Framework for Forecasting PM 2.5 Concentrations in Puli, Taiwan.
- Author
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Yin, Peng-Yeng, Yen, Alex Yaning, Chao, Shou-En, Day, Rong-Fuh, and Bhanu, Bir
- Subjects
PLANT mortality ,PLANT species ,CLIMATE change ,AUTOREGRESSION (Statistics) ,PREDICTION models ,FORECASTING - Abstract
Forecasting of PM
2.5 concentration is a global concern. Evidence has shown that the ambient PM2.5 concentrations are harmful to human health, climate change, plant species mortality, etc. PM2.5 concentrations are caused by natural and anthropogenic activities, and it is challenging to predict them due to many uncertain factors. Current research has focused on developing a new model while overlooking the fact that every single model for PM2.5 prediction has its own strengths and weaknesses. This paper proposes an ensemble framework which combines four diverse learning models for PM2.5 forecasting in Puli, Taiwan. It explores the synergy between parametric and non-parametric learning, and short-term and long-term learning. The feature set covers periodic, meteorological, and autoregression variables which are selected by a spiral validation process. The experimental dataset, spanning from 1 January 2008 to 31 December 2019, from Puli Township in central Taiwan, is used in this study. The experimental results show the proposed multi-model framework can synergize the advantages of the embedded models and obtain an improved forecasting result. Further, the benefit obtained by blending short-term learning with long-term learning is validated, in surpassing the performance obtained by using just single type of learning. Our multi-model framework compares favorably with deep-learning models on Puli dataset. It also shows high adaptivity, such that our multi-model framework is comparable to the leading methods for PM2.5 forecasting in Delhi, India. [ABSTRACT FROM AUTHOR]- Published
- 2022
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4. Tri-XGBoost model improved by BLSmote-ENN: an interpretable semi-supervised approach for addressing bankruptcy prediction.
- Author
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Smiti, Salima, Soui, Makram, and Ghedira, Khaled
- Subjects
BANKRUPTCY ,ARTIFICIAL intelligence ,RECEIVER operating characteristic curves ,DATA science ,FORECASTING - Abstract
Bankruptcy prediction is considered one of the most important research topics in the field of finance and accounting. The rapid increase of data science, artificial intelligence, and machine learning has led researchers to build an accurate bankruptcy prediction model. Recent studies show that ensemble methods perform better than traditional machine learning models for predicting corporate failure, especially with highly imbalanced datasets. However, the black box property of these techniques remains challenging to interpret the result and generate corporate classes without any explanation. To this end, we propose to build an accurate and interpretable classification model that generates a set of prediction rules for output. Tri-eXtreme Gradient Boosting (Tri-XGBoost), a semi-supervised technique, is recommended in this paper. The proposed method combines Borderline-Smote (BLSmote) based on Edited Nearest Neighbor (ENN) sampling techniques with three different XGBoost methods as weak classifiers (gbtree, gblinear, and dart). First, the resampling techniques are used to produce more representative synthetic data and balance the distribution of the datasets. To this end, BLSmote is applied to increase the proportion of instances in the minority class (bankrupt data). Then, ENN is used to eliminate the noisy samples from both classes. In addition, the most crucial features that increase predictive accuracy are chosen using XGBoost. Finally, in order to make the model more understandable for both applicants and experts, our result is presented as "IF–THEN" rules. Our proposed model is validated using the imbalanced Polish and Taiwan bankruptcy datasets. Our obtained results demonstrate that our suggested model performs better than the existing models based on the area under the ROC curve (AUC), F1-score, and G-mean performance measures. Our proposed model significantly improves classification accuracy, which is greater than 95% for Polish datasets and more than 93% for Taiwanese dataset in terms of AUC, G-mean and F1-score. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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5. Short-Term Traffic Flow Intensity Prediction Based on CHS-LSTM.
- Author
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Zhao, Lei, Wang, Quanmin, Jin, Biao, and Ye, Congmin
- Subjects
TRAFFIC flow ,FORECASTING ,INTELLIGENT transportation systems ,CLUSTER analysis (Statistics) ,HIERARCHICAL clustering (Cluster analysis) ,TRAFFIC engineering ,EUCLIDEAN distance - Abstract
Short-term traffic flow prediction is an important basis of intelligent transportation systems. Its accuracy directly affects the performance of traffic control and induction. To improve prediction accuracy, in this paper, a traffic flow prediction model is proposed by combining hierarchical agglomerative clustering (HAC), standardized Euclidean distance (SED), and a long short-term memory network (LSTM). The proposed model is called the CHS-LSTM model. In this model, HAC is used to carry out cluster analysis on the original traffic flow data sample set of target detection sections. Based on the results of cluster analysis, traffic flow data are divided into several categories. For different categories of traffic flow, SED is used to calculate the spatial correlation of the road network where the target sections are located, and the K sections most relevant to the target detection sections are used in the construction of an input data matrix for LSTM. The prediction result with the minimum root-mean-square error is regarded as the final prediction result. The electronic toll collection data of Taiwan are used as the fundamental data in this paper to verify the performance and effectiveness of the CHS-LSTM model. The experimental results indicate that the CHS-LSTM model can effectively improve the prediction accuracy of LSTM. Moreover, compared with well-known models generally used for predicting the intensity of traffic flow, our proposed model also shows its superiority. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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6. A parallel-series hybridization of seasonal intelligent based statistical model for demand forecasting.
- Author
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Bahrami, Maryam, Khashei, Mehdi, and Amindoust, Atefeh
- Subjects
DEMAND forecasting ,STATISTICAL models ,BOX-Jenkins forecasting ,SEASONS ,TIME series analysis - Abstract
Purpose: The purpose of this paper, because of the complexity of demand time series and the need to construct a more accurate hybrid model that can model all relationships in data, is to propose a parallel-series hybridization of seasonal neural networks and statistical models for demand time series forecasting. Design/methodology/approach: The main idea of proposed model is centered around combining parallel and series hybrid methodologies to use the benefit of unique advantages of both hybrid strategies as well as intelligent and classic seasonal time series models simultaneously for achieving results that are more accurate for the first time. In the proposed model, in contrast of traditional parallel and series hybrid strategies, it can be generally shown that the performance of the proposed model will not be worse than components. Findings: Empirical results of forecasting two well-known seasonal time series data sets, including the total production value of the Taiwan machinery industry and the sales volume of soft drinks, indicate that the proposed model can effectively improve the forecasting accuracy achieved by either of their components used in isolation. In addition, the proposed model can achieve more accurate results than parallel and series hybrid model with same components. Therefore, the proposed model can be used as an appropriate alternative model for seasonal time series forecasting, especially when higher forecasting accuracy is needed. Originality/value: To the best of the authors' knowledge, the proposed model, for first time and in contrast of traditional parallel and series hybrid strategies, is developed. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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7. Interactive tool for clustering and forecasting patterns of Taiwan COVID-19 spread.
- Author
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Ashouri, Mahsa and Phoa, Frederick Kin Hing
- Subjects
STATISTICAL smoothing ,COVID-19 ,WEB-based user interfaces ,MEDICAL research personnel ,DEMAND forecasting ,HIERARCHICAL clustering (Cluster analysis) ,FORECASTING - Abstract
The COVID-19 data analysis is essential for policymakers to analyze the outbreak and manage the containment. Many approaches based on traditional time series clustering and forecasting methods, such as hierarchical clustering and exponential smoothing, have been proposed to cluster and forecast the COVID-19 data. However, most of these methods do not scale up with the high volume of cases. Moreover, the interactive nature of the application demands further critically complex yet compelling clustering and forecasting techniques. In this paper, we propose a web-based interactive tool to cluster and forecast the available data of Taiwan COVID-19 confirmed infection cases. We apply the Model-based (MOB) tree and domain-relevant attributes to cluster the dataset and display forecasting results using the Ordinary Least Square (OLS) method. In this OLS model, we apply a model produced by the MOB tree to forecast all series in each cluster. Our user-friendly parametric forecasting method is computationally cheap. A web app based on R's Shiny App makes it easier for practitioners to find clustering and forecasting results while choosing different parameters such as domain-relevant attributes. These results could help in determining the spread pattern and be utilized by medical researchers. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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8. Financial Distress Prediction of Cooperative Financial Institutions—Evidence for Taiwan Credit Unions.
- Author
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Kang, Chien-Min, Wang, Ming-Chieh, and Lin, Lin
- Subjects
CREDIT unions ,FINANCIAL institutions ,BUSINESS forecasting ,MARKET volatility ,FORECASTING - Abstract
In response to relatively little evidence on the determinants of the financial distress in cooperative financial institutions (e.g., Credit Unions), this paper proposes a distress indicator of Merton Distance to default (Merton DD), which was constructed with a z-score, possessed improved predictive capability, but reducing equity volatility. This model possesses the advantages of both hazard and modified Merton DD model, which could timely reflect market volatility and predict when distress would occur. As a demonstration, we applied this model to forecast the financial distress of credit unions in Taiwan. The results can provide more information to researchers. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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9. The Effects of CSR Report Mandatory Policy on Analyst Forecasts: Evidence from Taiwan.
- Author
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Tseng, Tzu-Yun and Shih, Nien-Su
- Subjects
SOCIAL responsibility of business ,DISCLOSURE laws ,FORECASTING ,SOCIAL accounting - Abstract
The Taiwanese government altered its corporate social responsibility (CSR) report management policy from voluntary disclosure and assurance of CSR reports to partial mandatory disclosure and partial mandatory assurance. This paper examines this policy's effects on analyst forecast. The empirical results showed that the mandatory disclosure policy on CSR reports significantly increased analyst forecast accuracy and reduced analyst forecast dispersion. Furthermore, the study found that analyst forecast accuracy was further increased when CSR reports were forced to undergo accountant assurance than those without mandatory accountant assurance which means that the mandatory assurance policy on CSR reports significantly further increased analyst forecast accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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10. Model Establishment of Cross-Disease Course Prediction Using Transfer Learning.
- Author
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Ying, Josh Jia-Ching, Chang, Yen-Ting, Chen, Hsin-Hua, and Chao, Wen-Cheng
- Subjects
DEEP learning ,MEDICAL technology ,ARTIFICIAL intelligence ,TIME series analysis ,PREDICTION models ,FORECASTING - Abstract
In recent years, the development and application of artificial intelligence have both been topics of concern. In the medical field, an important direction of medical technology development is the extraction and use of applicable information from existing medical records to provide more accurate and helpful diagnosis suggestions. Therefore, this paper proposes using the development of diseases with easily discernible symptoms to predict the development of other medically related but distinct diseases that lack similar data. The aim of this study is to improve the ease of assessing the development of diseases in which symptoms are difficult to detect, and to improve the utilization of medical data. First, a time series model was used to capture the continuous manifestations of diseases with symptoms that could be easily found at different time intervals. Then, through transfer learning and attention mechanism, the general features captured were applied to the predictive model of the development of diseases with insufficient data and symptoms that are difficult to detect. Finally, we conducted a comprehensive experimental study based on a dataset collected from the National Health Insurance Research Database in Taiwan. The results demonstrate that the effectiveness of our transfer learning approach outperforms state-of-the-art deep learning prediction models for disease course prediction. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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- View/download PDF
11. Performance Evaluation and Forecasting for High School Admission Through School-Based Assessment in Taiwan.
- Author
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Wen-Tsung Lai
- Subjects
SCHOOL admission ,FORECASTING ,HIGH schools ,HIGH school seniors ,TIME series analysis - Abstract
Purpose: The purpose of this study is to evaluate why school-based assessment cannot be considered to compare the sequence of senior high school admissions that exceed the quota. Method: The study sample comprises 1,650 graduates whose Basic Competency Test (BCTEST) were considered for their high school admission in Taiwan during 2009--2013. The statistical forecasting methods used are fuzzy time series and self-regression. Result: The result is that the development trend of every student is considered by using the forecasting scores of fuzzy time series with the 17 stages of interval fuzzy scores. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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12. Transportation energy demand forecasting in Taiwan based on metaheuristic algorithms.
- Author
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Lashgari, Ali, Hosseinzadeh, Hasan, Khalilzadeh, Mohammad, Milani, Bahar, Ahmadisharaf, Amin, and Rashidi, Shima
- Subjects
DEMAND forecasting ,ENERGY consumption ,CURVE fitting ,ENERGY futures ,GROWTH rate - Abstract
A new methodology is suggested in this study to provide optimum forecasting of the future transportation energy demand in Taiwan. The paper introduces a new improved version of Emperor Penguin Optimizer (IEPO) to provide an optimal and suitable forecasting model. The forecasting was based on three different models including linear, exponential, and quadratic where their coefficients have been optimized using the suggested IEPO algorithm which is based on considering the population, the GDP growth rate, and the total annual vehicle-km. The study considers two different scenarios based on curve fitting and projection data. The results indicate that the RMS value for the TED forecasting based on the proposed IEPO algorithm applied to the linear, exponential, and Quadratic for training are 0.0452, 0.0461, and 0.0492, respectively and for testing are 0.0456, 0.0596, and 0.0642, respectively. This shows better results of the optimized exponential method's efficiency. Simulation results showed high efficiency for the proposed IEPO-based transportation energy demand forecasting based on all of the employed models for decision-making in ROC. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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13. Significant wave height forecasting using WRF-CLSF model in Taiwan strait.
- Author
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Ma, Jinshan, Xue, Honghui, Zeng, Yindong, Zhang, Zhenchang, and Wang, Qicong
- Subjects
NUMERICAL weather forecasting ,STRAITS ,WIND forecasting ,WAVES (Fluid mechanics) ,CONVOLUTIONAL neural networks ,COASTAL engineering ,FORECASTING - Abstract
Short-term hourly reliable prediction of significant wave height is an important research topic in coastal engineering. Many researchers have carried out in-depth studies in many ocean regions. Generally, most of this work is implemented through numerical models. However, as for numerical models, with the increase of hourly prediction duration, the accumulation of wave randomness leads to the poor prediction effect. In this paper, four buoy stations in the Taiwan Strait are taken as the research objects. We propose a significant wave height prediction algorithm, which combines numerical weather prediction model WRF and deep-learning model, called WRF-CLSF(Convolution-LSTM-FC). WRF can forecast 24-h wind speed in real-time, based on a variety of interpretable physical mechanisms. CLSF aims to extract the information of historical wind-wave interaction scale and the trend of wind-wave coherence, with the help of convolution operation and the time series model(LSTM), respectively. In the experiment, the proposed model was compared with the state-of-the-art prediction model. The results show that WRF-CLSF has an outstanding prediction effect at four buoy observation stations along with the Taiwan Strait. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
14. Initiative climate, psychological safety and knowledge sharing as predictors of team creativity: A multilevel study of research and development project teams.
- Author
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Liu, Yuwen, Keller, Robert T., and Bartlett, Kenneth R.
- Subjects
INFORMATION sharing ,RESEARCH & development projects ,FORECASTING ,ORGANIZATIONAL learning ,INDIVIDUALIZED instruction - Abstract
This paper examines from a multilevel perspective the contributions of initiative climate, psychological safety and knowledge sharing to team creativity in research and development (R&D) project teams. We propose and test an organizational learning contingency model of creativity, reflecting on how initiative climate interacts with employees' psychological safety in influencing knowledge sharing and teams' creative performance, by collecting data from 352 employees comprising 88 R&D teams in Taiwan at two time points and from two sources, team members and team leaders. Results indicated that knowledge sharing acts as a mediator in the relationship between initiative climate and team creativity. Results also supported the cross‐level moderation effect of initiative climate on the relationship between psychological safety and knowledge sharing behaviour. We also made the interesting but unhypothesized findings that tenure differentiation and education diversity both negatively influenced team creativity and go on to discuss both theoretical and practical implications of our research. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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15. Student Enrollment and Teacher Statistics Forecasting Based on Time-Series Analysis.
- Author
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Yang S, Chen HC, Chen WC, and Yang CH
- Subjects
- Humans, Taiwan, Time Factors, Forecasting methods, School Teachers statistics & numerical data, Schools, Students statistics & numerical data
- Abstract
Education competitiveness is a key feature of national competitiveness. It is crucial for nations to develop and enhance student and teacher potential to increase national competitiveness. The decreasing population of children has caused a series of social problems in many developed countries, directly affecting education and com.petitiveness in an international environment. In Taiwan, a low birthrate has had a large impact on schools at every level because of a substantial decrease in enrollment and a surplus of teachers. Therefore, close attention must be paid to these trends. In this study, combining a whale optimization algorithm (WOA) and support vector regression (WOASVR) was proposed to determine trends of student and teacher numbers in Taiwan for higher accuracy in time-series forecasting analysis. To select the most suitable support vector kernel parameters, WOA was applied. Data collected from the Ministry of Education datasets of student and teacher numbers between 1991 and 2018 were used to examine the proposed method. Analysis revealed that the numbers of students and teachers decreased annually except in private primary schools. A comparison of the forecasting results obtained from WOASVR and other common models indicated that WOASVR provided the lowest mean absolute percentage error (MAPE) and root mean square error (RMSE) for all analyzed datasets. Forecasting performed using the WOASVR method can provide accurate data for use in developing education policies and responses., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this paper., (Copyright © 2020 Stephanie Yang et al.)
- Published
- 2020
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16. Forecasting dengue and influenza incidences using a sparse representation of Google trends, electronic health records, and time series data.
- Author
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Rangarajan P, Mody SK, and Marathe M
- Subjects
- Brazil epidemiology, Electronic Health Records, Humans, Incidence, Internet trends, Mexico epidemiology, Models, Statistical, Population Surveillance methods, Singapore epidemiology, Taiwan epidemiology, Thailand epidemiology, Time Factors, United States epidemiology, Dengue epidemiology, Forecasting methods, Influenza, Human epidemiology
- Abstract
Dengue and influenza-like illness (ILI) are two of the leading causes of viral infection in the world and it is estimated that more than half the world's population is at risk for developing these infections. It is therefore important to develop accurate methods for forecasting dengue and ILI incidences. Since data from multiple sources (such as dengue and ILI case counts, electronic health records and frequency of multiple internet search terms from Google Trends) can improve forecasts, standard time series analysis methods are inadequate to estimate all the parameter values from the limited amount of data available if we use multiple sources. In this paper, we use a computationally efficient implementation of the known variable selection method that we call the Autoregressive Likelihood Ratio (ARLR) method. This method combines sparse representation of time series data, electronic health records data (for ILI) and Google Trends data to forecast dengue and ILI incidences. This sparse representation method uses an algorithm that maximizes an appropriate likelihood ratio at every step. Using numerical experiments, we demonstrate that our method recovers the underlying sparse model much more accurately than the lasso method. We apply our method to dengue case count data from five countries/states: Brazil, Mexico, Singapore, Taiwan, and Thailand and to ILI case count data from the United States. Numerical experiments show that our method outperforms existing time series forecasting methods in forecasting the dengue and ILI case counts. In particular, our method gives a 18 percent forecast error reduction over a leading method that also uses data from multiple sources. It also performs better than other methods in predicting the peak value of the case count and the peak time., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
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17. Recurrent Neural Network Based Short-Term Load Forecast with Spline Bases and Real-Time Adaptation.
- Author
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Yuan, Tzu-Lun, Jiang, Dian-Sheng, Huang, Shih-Yun, Hsu, Yuan-Yu, Yeh, Hung-Chih, Huang, Mong-Na Lo, and Lu, Chan-Nan
- Subjects
RECURRENT neural networks ,MOVING average process ,METEOROLOGICAL services ,FORECASTING - Abstract
Short-term load forecast (STLF) plays an important role in power system operations. This paper proposes a spline bases-assisted Recurrent Neural Network (RNN) for STLF with a semi-parametric model being adopted to determine the suitable spline bases for constructing the RNN model. To reduce the exposure to real-time uncertainties, interpolation is achieved by an adapted mean adjustment and exponentially weighted moving average (EWMA) scheme for finer time interval forecast adjustment. To circumvent the effects of forecasted apparent temperature bias, the forecasted temperatures issued by the weather bureau are adjusted using the average of the forecast errors over the preceding 28 days. The proposed RNN model is trained using 15-min interval load data from the Taiwan Power Company (TPC) and has been used by system operators since 2019. Forecast results show that the spline bases-assisted RNN-STLF method accurately predicts the short-term variations in power demand over the studied time period. The proposed real-time short-term load calibration scheme can help accommodate unexpected changes in load patterns and shows great potential for real-time applications. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
18. An occurrence based regime switching model to improve forecasting.
- Author
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Huarng, Kun-Huang
- Subjects
SWITCHING diodes ,FORECASTING ,STOCK exchanges ,VALUATION ,STOCK price indexes ,TIME series analysis - Abstract
Purpose – The purpose of this paper is to propose an occurrence-based model to improve the forecasting of regime switches so as to assist decision making. Design/methodology/approach – This paper proposes a novel model where occurrences of relationships are taken into account when forecasting. Taiwan Stock Exchange Capitalization Weighted Stock Index is taken as the forecasting target. Findings – Due to the consideration of occurrences of relationships in forecasting, the out of sample forecasting is improved. Practical implications – The proposed model can be applied to forecast other time series for regime switches. In addition, it can be integrated with other time series models to improve forecasting performance. Originality/value – The empirical results show that the proposed model can improve the forecasting performance. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
19. Status and forecast of leprosy in the still endemic province of Formosa in northern Argentina.
- Author
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Arnaiz, María R., Iglesias, Mónica S., Franco, José I., Arzamendia, Lucila, Santini, María S., and Recalde, Hugo C.
- Subjects
HANSEN'S disease ,AGE groups ,FORECASTING ,TIME series analysis ,DISEASE eradication ,BURULI ulcer - Abstract
Background: The province of Formosa, Argentina, is endemic for leprosy. In the present paper, we assessed the trend (T, 2002–2016 time series) and the forecast for 2022 of new case detection rate (NCDR) and determined the spatial distribution of new cases detected (NCD) of leprosy. Methodology/Principal findings: This is a descriptive observational study of 713 NCD of leprosy from provincial medical records between January 2002 and December 2016. The whole dataset from the provincial medical record was used to independently estimate the NCDR trends of the general population, age groups, sexes and Departments. This same database was used to estimate the NCDR forecast of the general population for 2022, applying a dynamic linear model with a local linear trend, using the MCMC algorithm. The NCDR was higher in men (p<0.05), increased with age (0.20, 8.17, 21.04, and 29.49 for the 0–14, 15–44, 45–64 and over 65-year-old age groups, respectively; p<0.05) and showed a downward trend (negative values) of estimated slopes for the whole province and each Department. Bermejo Department showed the highest (T:-1.02, 95%CI: [-1.42, -0.66]) and Patiño the lowest decreasing trend (T:-0.45, 95%CI: [-0.74, -0.11]). The NCDR trend for both sexes was similar (T:-0.55, 95%CI: [-0.64, -0.46]), and age groups showed a decreasing trend (S
15-44 :-103, S45-64 :-81, S>65 :-61, p<0.05), except for the 0–14 age group (S:-3, p>0.05), which showed no trend. Forecasts predicted that leprosy will not be eliminated by 2022 (3.64, 95%CI: [1.22, 10.25]). Conclusions/Significance: Our results highlight the status of leprosy in Formosa and provide information to the provincial public health authorities on high-risk populations, stressing the importance of timely detection of new cases for further elimination of the disease in the province. Author summary: Leprosy, a neglected tropical disease, is a public health problem in northern Argentina, causing permanent damage, stigmatization and discrimination. The Program for the Control of Leishmaniasis and Leprosy in Formosa province (PCLyLF) is responsible for the diagnosis and treatment of the disease and the active search for household contacts. The present study aimed to determine the spatial distribution of new cases of leprosy and the status of the disease using new case detection rate (NCDR) as the main epidemiological indicator. We determined the NCDR trends (2002–2016 time series) of the general population, age groups, sexes and Departments, and the NCDR forecast for the province by 2022. Our results indicated that leprosy was spread throughout Formosa, with higher rates in men and in patients over 65 years old. The NCDR showed a downward trend in the whole province and in each Department. The Departments of Bermejo and Matacos had the highest decreasing trend and the Department of Patiño the lowest one. Future projections show that leprosy will not be eliminated by 2022. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
20. Financial distress prediction model: The effects of corporate governance indicators.
- Author
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Chen, Chih‐Chun, Chen, Chun‐Da, and Lien, Donald
- Subjects
CORPORATE governance ,PREDICTION models ,FINANCIAL ratios ,FORECASTING ,DYNAMIC models - Abstract
This paper constructs a financial distress prediction model that includes not only traditional financial variables, but also several important corporate governance variables. Using data from Taiwan, the empirical results show that the best in‐sample and out‐of‐sample prediction models should combine the financial variables with the corporate governance variables. Moreover, the prediction accuracy is higher for the models using dynamic distress threshold values than those with tradition threshold values. Most financial ratios, except for the debt ratio, are higher in financially sound companies than in financial distressed ones. With regard to the corporate governance variables, we find that the CEO/Chairman duality may not result in the outbreak of financial distress, but higher equity pledge ratios of managers (shareholding ratios by board members and insiders) positively (negatively) correlate with financial distress. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
21. COMPARING THE FORECASTING ACCURACY OF PREDICTION MARKETS AND POLLS FOR TAIWAN'S PRESIDENTIAL AND MAYORAL ELECTIONS.
- Author
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Chen-yuan Tung, Tzu-Chuan Chou, Jih-wen Lin, and Hsin-yi Lin
- Subjects
PREDICTION markets ,INDUSTRIAL surveys ,ELECTIONS ,FORECASTING ,PUBLIC opinion polls - Abstract
This paper devises a methodology to compare the accuracy of prediction markets and polls. The data of the Exchange of Future Events (xFuture) for Taiwan's 2006 mayoral elections and 2008 presidential election show that the prediction markets outperform the opinion polls in various indices of accuracy. In terms of the last forecast before the election date, the accuracy of the prediction markets is 3 to 10 percent higher than that of the opinion polls. When comparing the accuracy of historical forecasts, the prediction markets outperform the polls in 93 to 100 percent of the cases. Moreover, the average accuracy of the prediction markets is 9 to 10 percent higher than that of the polls, with a standard deviation more than 2 percent less than that of the polls. To examine the robustness of these comparisons, this paper conducts two tests including daily forecast and normalized accuracy, and finds that the prediction markets successfully pass the tests with a significantly better accuracy than the polls. [ABSTRACT FROM AUTHOR]
- Published
- 2011
22. The Analysis of the Trend of Foreign Students Coming to Taiwan for Higher Education and the Marketing Strategy.
- Author
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Hsiao Ching-Mei and Wang Su-Man
- Subjects
FOREIGN students ,FORECASTING ,HIGHER education ,MARKETING strategy ,EXECUTIVE advisory bodies - Abstract
This paper applies grey forecast model to predict the number of foreign students coming from Asia, America, Europe, Oceania and other regions to Taiwan for higher education in the future. It also uses a viewpoint of service marketing to analyze the students' development in the future. The research outcomes can provide references of planning international alternating of higher education to higher education organizations and executive bodies. [ABSTRACT FROM AUTHOR]
- Published
- 2009
23. Analysis of interpolation algorithms for the missing values in IoT time series: a case of air quality in Taiwan.
- Author
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Yen, Neil Y., Chang, Jia-Wei, Liao, Jia-Yi, and Yong, You-Ming
- Subjects
TIME series analysis ,AIR quality ,INTERPOLATION algorithms ,MISSING data (Statistics) ,ARTIFICIAL neural networks ,DATA mining ,FORECASTING - Abstract
Missing values are common in the Internet of Things (IoT) environment for various reasons, including regular maintenance or malfunction. In time-series prediction in the IoT, missing values may have a relationship with the target labels, and their missing patterns result in informative missingness. Thus, missing values can be a barrier to achieving high accuracy of prediction and analysis in data mining in the IoT. Although several methods have been proposed to estimate values that are missing, few studies have investigated the comparison of interpolation methods using conventional and deep learning models. There has thus far been relatively little research into interpolation methods in the IoT environment. To address these problems, this paper presents the use of linear regression, support vector regression, artificial neural networks, and long short-term memory to make time-series predictions for missing values. Finally, a full comparison and analysis of interpolation methods are presented. We believe that these findings can be of value to future work in IoT applications. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
24. Rolling Grey Prediction of Taiwan IC Design Industry.
- Author
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Shih-Chi Chang and Hsiao-Cheng Yu
- Subjects
PREDICTION models ,MATHEMATICAL models ,FORECASTING ,INTEGRATED circuit layout - Abstract
In this paper, we constructed the Rolling Grey Forecasting Model (RGM) predict Taiwan IC design industry production to compare with ITRI's forecasting results. We explored enhancing the forecasting accuracy by selecting the p-value, one parameter RGM(1,1). To enhance the forecasting accuracy, this paper proposes a simple method determine the appropriate p-value. The forecasting results of a modified RGM(I,1) are superior to ITRI's forecast, showing that a modified RGM(1,1) is the appropriate model for forecasting IC design industry production. [ABSTRACT FROM AUTHOR]
- Published
- 2004
25. End-of-life photovoltaic modules: A systematic quantitative literature review.
- Author
-
Mahmoudi, Sajjad, Huda, Nazmul, Alavi, Zahraossadat, Islam, Md Tasbirul, and Behnia, Masud
- Subjects
LITERATURE reviews ,REVERSE logistics ,WASTE management ,GEOGRAPHICAL research ,TREND analysis ,REMANUFACTURING - Abstract
• A critical analysis of existing review papers are provided. • Geographical research distribution and gaps on End of life PV modules are depicted. • The scientific landscape of EoL PV panels by publication is mapped. • Bibliometric details of the papers in EoL PV management are tabulated. • Patents trend analysis on the treatment procedures of EoL PV modules is presented. PV modules which are installed worldwide have a defined lifetime for useful service after which the panels become End-of-Life (EoL) products. An enormous amount of obsolete solar PV modules will be added to the waste stream in the near future. Hence, the EoL photovoltaic waste stream could cause an appalling problem in the future if a holistic management strategy is not considered. Despite the vast research on photovoltaic technology, little is known about the perspective of how the EoL PV modules will be handled. The current study systematically investigates global research on EoL PV modules to identify gaps for further exploration. The review reveals that most of the research concentrates on the recovery and recycling of PV panels. Also, the vast majority of the research is mostly carried out in laboratory-scale. The geographical distribution of the studies was concentrated on 15 countries including the USA, Italy, and Taiwan, the latter of which has produced the most publications. Life-cycle-assessment and reverse logistics (RL) are two critical aspects of PV waste management and have only recently received attention from researchers, with 11 and six papers respectively. There are still many countries which have not attempted to forecast their EoL solar-panel waste stream and develop recycling infrastructure. Based on review findings, the future research must be focused on forecasting the PV waste streams, development of recycling technologies, reverse logistics and the policies of individual PV consumer countries. Finally, this study develops a foundation for future research on Photovoltaic waste management to build upon. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
26. 我國經濟成長率與其構成項目 近十年在「定基法」衡量下的 當季預測績效綜合評析
- Author
-
徐士勛
- Subjects
PUBLIC spending ,CONSUMPTION (Economics) ,BUSINESS cycles ,GROWTH rate ,FORECASTING ,EARNINGS forecasting - Abstract
Copyright of Taiwan Economic Forecast & Policy is the property of Institute of Economics, Academia Sinica, Taiwan Economic Forecast & Policy and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
27. Social media popularity and election results: A study of the 2016 Taiwanese general election.
- Author
-
Zhang, Xiaodong
- Subjects
ELECTIONS ,MAYORAL elections ,SOCIAL media ,REGRESSION analysis - Abstract
This paper investigates the relationship between candidates’ online popularity and election results, as a step towards creating a model to forecast the results of Taiwanese elections even in the absence of reliable opinion polls on a district-by-district level. 253 of 354 legislative candidates of single-member districts in Taiwan’s 2016 general election had active public Facebook pages during the election period. Hypothesizing that the relative popularity of candidates’ Facebook posts will be positively related to their election results, I calculated each candidate’s Like Ratio (i.e. proportions of all likes on Facebook posts obtained by candidates in their district). In order to have a measure of online interest without the influence of subjective positivity, I similarly calculated the proportion of daily average page views for each candidate’s Wikipedia page. I ran a regression analysis, incorporating data on results of previous elections and available opinion poll data. I found the models could describe the result of the election well and reject the null hypothesis. My models successfully predicted 80% of winners in single-member districts and were effective in districts without local opinion polls with a predictive power approaching that of traditional opinion polls. The models also showed good accuracy when run on data for the 2014 Taiwanese municipal mayors election. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
28. Week-ahead daily peak load forecasting using genetic algorithm-based hybrid convolutional neural network.
- Author
-
Ying-Yi Hong, Yu-Hsuan Chan, Yung-Han Cheng, Yih-Der Lee, Jheng-Lun Jiang, and Shen-Szu Wang
- Subjects
- *
PEAK load , *CONVOLUTIONAL neural networks , *RECURRENT neural networks , *CASCADE connections , *BIDDING strategies , *FORECASTING - Abstract
Daily peak load forecasting is crucial for the operation of bulk power systems, including economic dispatch and unit commitment. It is also essential for peak load shaving and load management in distribution systems. In power markets, peak load forecasting helps participants develop bidding strategies. This paper proposes a new method, using a hybrid convolutional neural network (CNN) that is cascaded with a fully-connected network, for making week-ahead daily peak load forecasts. The proposed method uses three loops to obtain the optimal CNN: The outer loop performs crossover/mutation operations and tournament selection to produce chromosomes to optimize the network topology and hyperparameters (such as kernel size) of the hybrid CNN by genetic algorithms; the middle loop deals with the order of chromosomes; the inner loop optimizes the synaptic weights and parameters (e.g. values of a kernel) using Adam optimizer. Daily peak load data and corresponding meteorological data for Taiwan are explored. Simulation results show that the proposed method outperforms the traditional CNN, multi-layer neural network, recurrent neural network, support vector regression and vector autoregressive moving average model. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
29. A quantile regression forecasting model for ICT development.
- Author
-
Yu, Tiffany Hui-Kuang
- Subjects
QUANTILE regression ,ECONOMIC forecasting ,INFORMATION & communication technologies ,WAGE differentials ,LEAST squares ,LINEAR programming - Abstract
Purpose – Because quantile regression gets more popular and provides more comprehensive interpretations, it is important to advance quantile regression for forecasting. By extending the convention quantile regression, the purpose of this paper is to propose a quantile regression-forecasting model to forecast information and communication technology (ICT) development. Design/methodology/approach – This paper proposes an approach to forecasting based on quantile regression method. Findings – Via quantile information criterion, the proposed approach can identify whether the independent variables are predictable. For those which are predictable, the proposed approach can be used to forecast these variables. Practical implications – The proposed approach is used to forecast ICT development. It can also be used to forecast other problem domains. Originality/value – Based on the empirical results, the proposed approach advances the application of quantile regression model to forecast. The applicability of quantile regression model is greatly enhanced. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
30. Corporate Misconduct Prediction with Support Vector Machine in the Construction Industry.
- Author
-
Wang, Ran, Lee, Chia-Jung, Hsu, Shu-Chien, and Lee, Cheng-Yu
- Subjects
SUPPORT vector machines ,FORECASTING ,MACHINERY industry ,CONSTRUCTION industry ,FALSIFICATION of data ,LOGISTIC regression analysis ,CONSTRUCTION industry personnel - Abstract
Corporate misconduct may lead to severe economic loss and even fatal injuries to workers and residents in the construction industry. Previous studies have proven that board composition in organizations can be related to illegal business behaviors. By analyzing board composition data from 45 publicly listed construction companies in Taiwan, this paper provides a tool for predicting corporate misconduct (CM). A support vector machine (SVM) was used to construct such a prediction model, and a logistic regression model was used as a benchmark to assess the performance of the established SVM model. The established SVM model achieved an accuracy rate of 72.22% for predicting the occurrence of CM when applied to all observations in the sample, with a rate of 90% accuracy in predicting misconduct by companies found guilty of doing so in the sample, thus performing better than the logistic regression model. The developed model yields new insights on previous research and can guide stakeholders to reduce the risk of illegal business acts occurring in the construction industry. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
31. Forecasting Trading-Session Return Volatility in Taiwan Futures Market: A Periodic Regime Switching with Jump Approach.
- Author
-
Lai, Yi-Hao, Wang, Yi-Chiuan, and Chang, Yu-Ching
- Subjects
VOLATILITY (Securities) ,MARKET volatility ,FUTURES market ,FORECASTING ,INVESTMENT risk ,INVESTMENT management ,JUMP processes - Abstract
This study develops a novel periodic regime-switching model (the PRS model) to improve the forecasting of stock market volatility by accounting for the information from non-trading and trading periods, including regular trading and after-hour trading. Empirical analysis of the Taiwan Futures Exchange (TAIFEX) demonstrates the significant improvements of the PRS model in both in-sample and out-of-sample periods. Our results also show that the introduction of after-hour trading sessions has provided valuable information for volatility forecasting in subsequent regular trading sessions, emphasizing the importance of considering diverse information flows across different trading and non-trading times. The PRS model effectively captures the dynamics of non-trading and trading sessions and the influence of unusual news arrivals and jumps on market volatility, contributing to investment and risk management strategies. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Hypothesis testing for performance evaluation of probabilistic seasonal rainfall forecasts.
- Author
-
Cheng, Ke-Sheng, Yu, Gwo‑Hsing, Tai, Yuan-Li, Huang, Kuo-Chan, Tsai, Sheng‑Fu, Wu, Dong‑Hong, Lin, Yun-Ching, Lee, Ching-Teng, and Lo, Tzu-Ting
- Subjects
DISTRIBUTION (Probability theory) ,SEASONS ,SUMMER ,FORECASTING ,RAINFALL ,HYPOTHESIS - Abstract
A hypothesis testing approach, based on the theorem of probability integral transformation and the Kolmogorov–Smirnov one-sample test, for performance evaluation of probabilistic seasonal rainfall forecasts is proposed in this study. By considering the probability distribution of monthly rainfalls, the approach transforms the tercile forecast probabilities into a forecast distribution and tests whether the observed data truly come from the forecast distribution. The proposed approach provides not only a quantitative measure for performance evaluation but also a cumulative probability plot for insightful interpretations of forecast characteristics such as overconfident, underconfident, mean-overestimated, and mean-underestimated. The approach has been applied for the performance evaluation of probabilistic season rainfall forecasts in northern Taiwan, and it was found that the forecast performance is seasonal dependent. Probabilistic seasonal rainfall forecasts of the Meiyu season are likely to be overconfident and mean-underestimated, while forecasts of the winter-to-spring season are overconfident. A relatively good forecast performance is observed for the summer season. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. TAIEX Forecasting Using Fuzzy Time Series and Automatically Generated Weights of Multiple Factors.
- Author
-
Chen, Shyi-Ming, Chu, Huai-Ping, and Sheu, Tian-Wei
- Subjects
STOCK exchanges ,FUZZY sets ,STATISTICAL correlation ,STOCK price indexes - Abstract
In this paper, we present a new method to forecast the Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) using fuzzy time series and automatically generated weights of multiple factors. The proposed method uses the variation magnitudes of adjacent historical data to generate fuzzy variation groups of the main factor (i.e., the TAIEX) and the elementary secondary factors (i.e., the Dow Jones, the NASDAQ and the M1B), respectively. Based on the variation magnitudes of the main factor TAIEX and the elementary secondary factors of a particular trading day, it constructs the occurrence vector of the main factor and the occurrence vectors of the elementary secondary factors on the trading day, respectively. By calculating the correlation coefficients between the numerical data series of the main factor and the numerical data series of each elementary secondary factor, respectively, it calculates the relevance degree between the forecasted variation of the main factor and the forecasted variation of each elementary secondary factor. Based on the correlation coefficients between the numerical data series of the main factor and the numerical data series of each elementary secondary factor on a trading day, it automatically generates the weights of the occurrence vector of the main factor and the occurrence vector of each elementary secondary factor on the trading day, respectively. Then, it calculates the forecasted variation of the main factor and the forecasted variation of each elementary secondary factor on the trading day, respectively, to obtain the final forecasted variation on the trading day. Finally, based on the closing index of the TAIEX on the trading day and the final forecasted variation on the trading day, it generates the forecasted value of the next trading day. The experimental results show that the proposed method outperforms the existing methods. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
34. Multiregion Short-Term Load Forecasting in Consideration of HI and Load/Weather Diversity.
- Author
-
Chu, Wen-Chen, Chen, Yi-Ping, Xu, Zheng-Wei, and Lee, Wei-Jen
- Subjects
HEATING load ,HUMIDITY ,HEAT index ,ARTIFICIAL neural networks ,REGRESSION analysis ,WEATHER forecasting - Abstract
The ultimate goal of an electric utility is to create maximum profit while maintaining reliability and security of the power supply. The operation and control of power system is sensitive to system demand. Therefore, improvements in load-forecasting accuracy will lead to cost savings and enhance system security. Due to Taiwan's distinct climate characteristics, it is difficult to obtain satisfactory load-forecasting results by treating the whole island as a single region. In addition, weather factors, such as temperature, relative humidity, and the Heat Index (HI) (a human-perceived equivalent temperature) may also affect load-consumption patterns. This paper proposes a multiregion short-term load-forecasting methodology, taking into account the HI to improve load-forecasting accuracy in Taiwan Power Company's (Taipower's) system. The results show that adopting the HI as a parameter can effectively improve the accuracy if the temperature of the region under investigation is above 27 ^\circ\C (80 ^ \circ\F). By considering both the load/weather diversity and the HI, further improvements to the load forecasting for the Taipower system during summer can be achieved. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
35. An efficient forecasting model based on an improved fuzzy time series and a modified group search optimizer.
- Author
-
Lee, Chin-Ling, Kuo, Shye-Chorng, and Lin, Cheng-Jian
- Subjects
FORECASTING ,TIME series analysis ,STOCK price indexes - Abstract
This paper presents a prediction model based on an improved fuzzy time series (IFTS) and a modified group search optimizer to effectively solve forecasting problems. IFTS can accurately predict whether subsequent predicted data will increase or decrease according to ratio value in the fuzzy logical relationship. In addition, the modified group search optimizer is used to adjust the length of an interval. The proposed prediction model is also used to forecast the enrollments of the University of Alabama the enrollments of a university of technology in central Taiwan, and the Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) Experimental results show that the proposed model obtains the smallest prediction error than those of other methods. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
36. Mapping the montane cloud forest of Taiwan using 12 year MODIS-derived ground fog frequency data.
- Author
-
Schulz, Hans Martin, Li, Ching-Feng, Thies, Boris, Chang, Shih-Chieh, and Bendix, Jörg
- Subjects
CLOUD forests ,FOREST mapping ,MOUNTAIN ecology ,LANDSAT satellites - Abstract
Up until now montane cloud forest (MCF) in Taiwan has only been mapped for selected areas of vegetation plots. This paper presents the first comprehensive map of MCF distribution for the entire island. For its creation, a Random Forest model was trained with vegetation plots from the National Vegetation Database of Taiwan that were classified as “MCF” or “non-MCF”. This model predicted the distribution of MCF from a raster data set of parameters derived from a digital elevation model (DEM), Landsat channels and texture measures derived from them as well as ground fog frequency data derived from the Moderate Resolution Imaging Spectroradiometer. While the DEM parameters and Landsat data predicted much of the cloud forest’s location, local deviations in the altitudinal distribution of MCF linked to the monsoonal influence as well as the Massenerhebung effect (causing MCF in atypically low altitudes) were only captured once fog frequency data was included. Therefore, our study suggests that ground fog data are most useful for accurately mapping MCF. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
37. A Method of Multi-Stage Reservoir Water Level Forecasting Systems: A Case Study of Techi Hydropower in Taiwan.
- Author
-
Tsao, Hao-Han, Leu, Yih-Guang, Chou, Li-Fen, and Tsao, Chao-Yang
- Subjects
WATER levels ,WATER power ,FUZZY neural networks ,FLOOD control ,WATER supply ,FORECASTING - Abstract
Reservoirs in Taiwan often provide hydroelectric power, irrigation water, municipal water, and flood control for the whole year. Taiwan has the climatic characteristics of concentrated rainy seasons, instantaneous heavy rains due to typhoons and rainy seasons. In addition, steep rivers in mountainous areas flow fast and furiously. Under such circumstances, reservoirs have to face sudden heavy rainfall and surges in water levels within a short period of time, which often causes the water level to continue to rise to the full level even though hydroelectric units are operating at full capacity, and as reservoirs can only drain the flood water, this results in the waste of hydropower resources. In recent years, the impact of climate change has caused extreme weather events to occur more frequently, increasing the need for flood control, and the reservoir operation has faced severe challenges in order to fulfil its multipurpose requirements. Therefore, in order to avoid the waste of hydropower resources and improve the effectiveness of the reservoir operation, this paper proposes a real-time 48-h ahead water level forecasting system, based on fuzzy neural networks with multi-stage architecture. The proposed multi-stage architecture provides reservoir inflow estimation, 48-h ahead reservoir inflow forecasting, and 48-h ahead water level forecasting. The proposed method has been implemented at the Techi hydropower plant in Taiwan. Experimental results show that the proposed method can effectively increase energy efficiency and allow the reservoir water resources to be fully utilized. In addition, the proposed method can improve the effectiveness of the hydropower plant, especially when rain is heavy. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
38. Impact of the COVID-19 Pandemic on the Revenue of the Catering Industry: Taiwan as an Example.
- Author
-
Hsin-Chieh Wu, Tin-Chih Toly Chen, and Syuan Yu Wang
- Subjects
COVID-19 pandemic ,CATERING services ,BUSINESS revenue ,BUSINESS planning ,RANDOM forest algorithms - Abstract
Due to the impact of the COVID-19 pandemic, people have reduced eating out, resulting in a severe drop in the revenue of the catering industry. Health risks have become a major factor affecting the revenue of this industry. Predicting the revenue of the catering industry during the COVID-19 pandemic will not only allow practitioners to adjust their business strategies, but also provide a reference for governments to formulate relief measures. To this end, this study proposes a fuzzy big data analytics approach in which random forests, recursive feature elimination, fuzzy c-means, and deep neural networks are jointly applied. First, random forests and recursive feature elimination are used to select the most influential factors. The data is then divided into clusters by fuzzy c-means. Subsequently, a deep neural network is built for each cluster to make predictions. The prediction results of individual clusters are then aggregated to improve prediction accuracy. The proposed methodology has been applied to forecast the revenue of the catering industry in Taiwan. The results of the experiment showed that the impact of new deaths on the revenue of the catering industry was far greater than the number of newly diagnosed COVID-19 cases. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. A novel rainfall forecast model using GNSS observations and CAPE in Singapore.
- Author
-
Liu, Zhuoya, Wen, Yi, Zhang, Xun, Wang, Mian, Xiao, Shuzhou, Chen, Yuan, and He, Lin
- Subjects
- *
GLOBAL Positioning System , *PRECIPITABLE water , *RAINFALL , *STANDARD deviations , *FORECASTING - Abstract
Precipitable water vapor (PWV) and zenith total delay (ZTD) are highly correlated indicators used for forecasting rainfall effectively. These two factors are widely used when establishing qualitative and quantitative rainfall forecast models. Another indicator, however, convective available potential energy (CAPE), is also highly correlated with the occurrence of rainfall, but has not been combined with PWV or ZTD in previous studies. Therefore, a novel rainfall forecast model based on support vector regression that combines CAPE and Global Navigation Satellite System (GNSS)-derived PWV is proposed in this paper. Moreover, annual, seasonal scales, and hourly autocorrelation for predictors were also considered, and wavelet coherence (WTC) was introduced to further reveal the correlation relationships between CAPE, PWV and rainfall in both time and frequency domains. Hourly PWV, CAPE, temperature (T) and rainfall over a time span of three years were collected from four stations in Singapore and Taiwan to evaluate the performance of the proposed model. The root mean square error (RMSE) and mean absolute error (MAE) between the measured and forecasted rainfall were calculated for each year and averaged. Subsequently, the average RMSE and MAE were determined for the annual seasonal rainfall. The annual average RMSE value was 0.71 mm and the average annual seasonal RMSE value was 0.69 mm. The annual average MAE value was 0.21 mm and the annual seasonal was 0.22 mm. The average correlation coefficient (R2) for the annual value was 0.94 and the annual seasonal R2 value was 0.93. These results indicate that the forecast accuracy at the seasonal scale is basically consistent with annual scale. Additionally, a measure called comparable RMSE (CRMS) was introduced to evaluate the forecasting accuracy across all grades of rainfall. This analysis showed that the accuracy of moderate rainfall (MR) and heavy rainfall (HR) forecasts is similar, but slight rainfall (SR) forecasts are the most accurate among seasons and schemes. • A short-term rainfall forecast method is proposed using convective available potential energy (CAPE) and GNSS-derived PWV. • The forecast accuracy of seasonal scales is consistent with annual scale. • Results showed that the forecast accuracy of moderate rainfall and heavy rainfall were comparable while that of slight rainfall was highest. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. Bayesian Forecasting of Bounded Poisson Distributed Time Series.
- Author
-
Liu, Feng-Chi, Chen, Cathy W. S., and Ho, Cheng-Ying
- Subjects
AIR quality indexes ,FORECASTING ,CREDIT ratings ,POISSON distribution ,BAYESIAN field theory - Abstract
This research models and forecasts bounded ordinal time series data that can appear in various contexts, such as air quality index (AQI) levels, economic situations, and credit ratings. This class of time series data is characterized by being bounded and exhibiting a concentration of large probabilities on a few categories, such as states 0 and 1. We propose using Bayesian methods for modeling and forecasting in zero-one-inflated bounded Poisson autoregressive (ZOBPAR) models, which are specifically designed to capture the dynamic changes in such ordinal time series data. We innovatively extend models to incorporate exogenous variables, marking a new direction in Bayesian inferences and forecasting. Simulation studies demonstrate that the proposed methods accurately estimate all unknown parameters, and the posterior means of parameter estimates are robustly close to the actual values as the sample size increases. In the empirical study we investigate three datasets of daily AQI levels from three stations in Taiwan and consider five competing models for the real examples. The results exhibit that the proposed method reasonably predicts the AQI levels in the testing period, especially for the Miaoli station. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. A Global Solar Radiation Forecasting System Using Combined Supervised and Unsupervised Learning Models.
- Author
-
Wei, Chih-Chiang and Yang, Yen-Chen
- Subjects
SOLAR radiation ,GLOBAL radiation ,MACHINE learning ,SUPERVISED learning ,SOLAR energy ,SOLAR technology ,FORECASTING ,FUZZY neural networks ,EARTH stations - Abstract
One of the most important sources of energy is the sun. Taiwan is located at a 22–25° north latitude. Due to its proximity to the equator, it experiences only a small angle of sunlight incidence. Its unique geographical location can obtain sustainable and stable solar resources. This study uses research on solar radiation forecasts to maximize the benefits of solar power generation, and it develops methods that can predict future solar radiation patterns to help reduce the costs of solar power generation. This study built supervised machine learning models, known as a deep neural network (DNN) and a long–short-term memory neural network (LSTM). A hybrid supervised and unsupervised model, namely a cluster-based artificial neural network (k-means clustering- and fuzzy C-means clustering-based models) was developed. After establishing these models, the study evaluated their prediction results. For different prediction periods, the study selected the best-performing model based on the results and proposed combining them to establish a real-time-updated solar radiation forecast system capable of predicting the next 12 h. The study area covered Kaohsiung, Hualien, and Penghu in Taiwan. Data from ground stations of the Central Weather Administration, collected between 1993 and 2021, as well as the solar angle parameters of each station, were used as input data for the model. The results of this study show that different models offer advantages and disadvantages in predicting different future times. The hybrid prediction system can predict future solar radiation more accurately than a single model. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
42. Hybrid Post-Processing on GEFSv12 Reforecast for Summer Maximum Temperature Ensemble Forecasts with an Extended-Range Time Scale over Taiwan.
- Author
-
Nageswararao, Malasala Murali, Zhu, Yuejian, Tallapragada, Vijay, and Chen, Meng-Shih
- Subjects
ARTIFICIAL neural networks ,LONG-range weather forecasting ,SUMMER ,FORECASTING ,ATMOSPHERIC temperature ,DEEP learning ,GLOBAL warming - Abstract
Taiwan is highly susceptible to global warming, experiencing a 1.4 °C increase in air temperature from 1911 to 2005, which is twice the average for the Northern Hemisphere. This has potentially led to higher rates of respiratory and cardiovascular mortality. Accurately predicting maximum temperatures during the summer season is crucial, but numerical weather models become less accurate and more uncertain beyond five days. To enhance the reliability of a forecast, post-processing techniques are essential for addressing systematic errors. In September 2020, the NOAA NCEP implemented the Global Ensemble Forecast System version 12 (GEFSv12) to help manage climate risks. This study developed a Hybrid statistical post-processing method that combines Artificial Neural Networks (ANN) and quantile mapping (QQ) approaches to predict daily maximum temperatures (T
max ) and their extremes in Taiwan during the summer season. The Hybrid technique, utilizing deep learning techniques, was applied to the GEFSv12 reforecast data and evaluated against ERA5 reanalysis. The Hybrid technique was the most effective among the three techniques tested. It had the lowest bias and RMSE and the highest correlation coefficient and Index of Agreement. It successfully reduced the warm bias and overestimation of Tmax extreme days. This led to improved prediction skills for all forecast lead times. Compared to ANN and QQ, the Hybrid method proved to be more effective in predicting daily Tmax , including extreme Tmax during summer, on extended-range time-scale deterministic and ensemble probabilistic forecasts over Taiwan. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
43. Fuzzy forecasting based on fuzzy-trend logical relationship groups.
- Author
-
Chen SM and Wang NY
- Subjects
- Computer Simulation, Taiwan, Algorithms, Artificial Intelligence, Forecasting, Fuzzy Logic, Logistic Models, Models, Econometric, Pattern Recognition, Automated methods
- Abstract
In this paper, we present a new method to predict the Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) based on fuzzy-trend logical relationship groups (FTLRGs). The proposed method divides fuzzy logical relationships into FTLRGs based on the trend of adjacent fuzzy sets appearing in the antecedents of fuzzy logical relationships. First, we apply an automatic clustering algorithm to cluster the historical data into intervals of different lengths. Then, we define fuzzy sets based on these intervals of different lengths. Then, the historical data are fuzzified into fuzzy sets to derive fuzzy logical relationships. Then, we divide the fuzzy logical relationships into FTLRGs for forecasting the TAIEX. Moreover, we also apply the proposed method to forecast the enrollments and the inventory demand, respectively. The experimental results show that the proposed method gets higher average forecasting accuracy rates than the existing methods.
- Published
- 2010
- Full Text
- View/download PDF
44. Infiltration mechanism simulation of artificial groundwater recharge: a case study at Pingtung Plain, Taiwan.
- Author
-
Hsun-Huang Hsieh, Cheng-Haw Lee, Cheh-Shyh Ting, and Jung-Wei Chen
- Subjects
ARTIFICIAL groundwater recharge ,WATER seepage ,AQUIFERS ,FORECASTING ,HYDROGEOLOGY methodology - Abstract
This paper discusses the artificial groundwater recharge effect of high-infiltration basins. For this purpose, the hydrogeological parameters of the study area are collected to construct a conceptualized physical model. The TOUGH2 numerical simulation software is then used to simulate the infiltration behavior of an artificial recharge into an underground aquifer. Four wells (MW-1, MW-2, MW-3, and MW-4) are observed at the field site, after which the groundwater levels are compared with the simulation results. It is found that good agreement exists between the observed and numerical data for MW-1 and MW-2. However, the observed groundwater level in MW-3 is higher than the simulated level. We also find that MW-3 is at the edge of the artificial recharge lake, and that the high groundwater level may well be the result of a portion of the infiltration load following the well border into the well screen. Conversely, the groundwater level in MW-4 is found to be lower than in the simulated well due to local permeability in the well location. Finally, the numerical results predict that the groundwater level will attain a steady state at approximately 47 h after the onset of infiltration. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
45. A Seasonal ARIMA Model of Tourism Forecasting: The Case of Taiwan.
- Author
-
Chang, Yu-Wei and Liao, Meng-Yuan
- Subjects
TOURISM research ,TOURISTS ,SEASONAL tourism ,BUSINESS forecasting ,OUTBOUND tourism ,INTERNATIONAL tourism - Abstract
This paper aims to determine suitable SARIMA models to forecast the monthly outbound tourism departures of three major destinations from Taiwan to Hong Kong, Japan and the USA, respectively. The HEGY test is used to identify the deterministic seasonality in the data. The mean absolute per cent error (MAPE) is used to measure forecast accuracy. A low MAPE demonstrates the adequacy of the fitted SARIMA models. The results indicate that all series with first non-seasonal difference are needed to obtain the deterministic trend in outbound tourism series in Taiwan. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
46. Model for Predicting Financial Performance of Development and Construction Corporations.
- Author
-
Hong Long Chen
- Subjects
CONSTRUCTION industry ,FINANCIAL performance ,TIME series analysis ,FINANCIAL management ,BUSINESS forecasting - Abstract
Performance forecasting is central to aligning an organization’s operations with its strategic direction. Despite the panoply of approaches to performance predictions, relatively few published studies address model development of financial performance predictions for the construction industry. By analyzing the preceding relationship between financial and economic variables and financial performance, this paper proposes an innovative approach to predicting firm financial performance. First, hypothesis tests using data for 42 development and construction corporations listed in the construction sector of the Taiwan Stock Exchange between 1997 Q1 and 2006 Q4 uncover useful relationships between financial performance and financial and economic variables. Second, based on these relationships, a three-stage mathematical modeling procedure is used for cross-sectional model estimation, which is subsequently refined to create firm-specific financial performance-forecasting models for four sample firms. The out-of-sample forecasting accuracy is evaluated using mean absolute percentage error (MAPE). The results show that the cross-sectional model explains 78.9% of the variation in the cross-sectional performance data, and the MAPE values in the forecasting models range from 9.54 to 19.69%. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
47. A comparison of univariate methods for forecasting container throughput volumes
- Author
-
Peng, Wen-Yi and Chu, Ching-Wu
- Subjects
- *
CONTAINER ships , *FORECASTING , *MATHEMATICAL models , *MATHEMATICAL decomposition , *TRIGONOMETRY , *REGRESSION analysis , *PREDICTION models , *CONTAINER terminals - Abstract
Abstract: In this paper, six univariate forecasting models for the container throughput volumes in Taiwan’s three major ports are presented. The six univariate models include the classical decomposition model, the trigonometric regression model, the regression model with seasonal dummy variables, the grey model, the hybrid grey model, and the SARIMA model. The purpose of this paper is to search for a model that can provide the most accurate prediction of container throughput. By applying monthly data to these models and comparing the prediction results based on mean absolute error, mean absolute percent error and root mean squared error, we find that in general the classical decomposition model appears to be the best model for forecasting container throughput with seasonal variations. The result of this study may be helpful for predicting the short-term variation in demand for the container throughput of other international ports. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
48. Assessing the Impact of Dropsonde Data on Rain Forecasts in Taiwan with Observing System Simulation Experiments.
- Author
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Chien, Fang-Ching and Chiu, Yen-Chao
- Subjects
TROPICAL cyclones ,SIMULATION methods & models ,FORECASTING - Abstract
This paper presents an observing system simulation experiment (OSSE) study to examine the impact of dropsonde data assimilation (DA) on rainfall forecasts for a heavy rain event in Taiwan. The rain event was associated with strong southwesterly flows over the northern South China Sea (SCS) after a weakening tropical cyclone (TC) made landfall over southeastern China. With DA of synthetic dropsonde data over the northern SCS, the model reproduces more realistic initial fields and a better simulated TC track that can help in producing improved low-level southwesterly flows and rainfall forecasts in Taiwan. Dropsonde DA can also aid the model in reducing the ensemble spread, thereby producing more converged ensemble forecasts. The sensitivity studies suggest that dropsonde DA with a 12-h cycling interval is the best strategy for deriving skillful rainfall forecasts in Taiwan. Increasing the DA interval to 6 h is not beneficial. However, if the flight time is limited, a 24-h interval of DA cycling is acceptable, because rainfall forecasts in Taiwan appear to be satisfactory. It is also suggested that 12 dropsondes with a 225-km separation distance over the northern SCS set a minimum requirement for enhancing the model regarding rainfall forecasts. Although more dropsonde data can help the model to obtain better initial fields over the northern SCS, they do not provide more assistance to the forecasts of the TC track and rainfall in Taiwan. These findings can be applied to the future field campaigns and model simulations in the nearby regions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
49. A Study of the Prophecies Attributed to Liu Bowen in Circulation in Taiwan.
- Author
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Chan Hok-lam and Wang Chien-chuan
- Subjects
- *
PROPHECY , *FORECASTING ,HISTORY of Taiwan ,TAIWANESE politics & government - Abstract
This is a joint study of the prophecies attributed to Liu Bowen in circulation in Taiwan during the nineteenth and twentieth centuries. Liu Bowen was the courtesy name of Liu Ji, an eminent adviser to the Ming dynasty founder Zhu Yuanzhang (Ming Taizu, r. 1368- 1398). Since the late seventeenth century during the Ming-Qing transition, however, under the name of Liu Bowen, Liu Ji has been systematically mythologized as a legendary figure, becoming known as a clairvoyant prognosticator and an ingenious builder of imperial cities in modern times. In addition to a profusion of prophecies attributed to him during periods of social and political crises, he is best known as the author of a prophecy book known as Shaobing ge (Baked Cake Ballad), prophesying the events of China during the last six hundred years with incredible accuracy and proposing means of salvation. While his name and his works have been well known in mainland China, the Shaobing ge and other prophecies attributed to him were also in vogue in Taiwan under Japanese colonial rule and have remained in circulation in the island since its return to Chinese suzerainty after the Second World War. This paper is divided into four parts, with contributions shared by both authors. The first part gives a summary of the state of research on Liu Ji's Shaobing ge, tracing the inception of its prophecies in the late Ming and early Qing to the work of fiction writers and the propagandists of the anti-Manchu sectarian organizations and secret societies in the eighteenth century. Additional prophecies attributed to Liu Ji proliferated thereafter onto the 1930s. The earliest edition of Shaobing ge which the authors have seen or in their possession was printed in the late Guangxu period (1875-1908) but it was probably based on much earlier cruder manuscripts. The book has been well received in Taiwan since that time. The second part examines Taiwanese publications under Japanese colonial rule attesting to the popularity of Liu Bowen's alleged prophecies. The first source was discussions on the origin of the Shaobing ge and its purposes by Taiwanese scholars published in the Sino-Japanese Taiwan daily newspaper Taiwan Riri Xinbao, dated November 20 and December 3, 1898, the thirty-first year of Meiji. There one commentator suggested that the author of Shaobing ge may have been an adviser to the leaders of the Taiping Heavenly Kingdom in the mid nineteenth century, and pointed out that several individual prophecies later collected in the Shaobing ge were already well known in Taiwan at that time. Another Taiwanese publication gives information that Liu Bowen had been adulated by the local people as a deity of salvation and the Shaobing ge had been cited by ringleaders of the anti-Japanese Taiwanese uprising in Tainan in 1915 to presage victory. The third part of the paper examines the worship and distribution of Liu Bowen's alleged prophecies known as Liu Bowen chen or Liu Bowen xiansheng xianchu jiujiebei wen by a group of followers of the banned sectarian organization known as Yiguan Sect in the city of Gaoxiong in southern Taiwan in the 1960s. It reproduces the recently declassified police records of the Guomindang Government on these episodes with an analysis of the contents of the prophecies and the motives of the worshippers. It shows that the worshippers harbored no political agenda but aspired to blessings from Liu Bowen for a healthy and happy life. The final part of the paper gives a textual analysis of the Liu Bowen chen or Liu Bowen jiujiebei wen propagated by sectarian organizations in Taiwan with similar non-violent social goals.… [ABSTRACT FROM AUTHOR]
- Published
- 2007
50. Comparing linear and nonlinear forecasts for Taiwan's electricity consumption
- Author
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Pao, Hsiao-Tien
- Subjects
- *
ENERGY consumption , *FORECASTING , *PREDICTION models - Abstract
Abstract: This paper uses linear and nonlinear statistical models, including artificial neural network (ANN) methods, to investigate the influence of the four economic factors, which are the national income (NI), population (POP), gross of domestic production (GDP), and consumer price index (CPI) on the electricity consumption in Taiwan and then to develop an economic forecasting model. Both methods agree that POP and NI influence electricity consumption the most, whereas GDP the least. The results of comparing the out-of-sample forecasting capabilities of the two methods indicate the following. (1) If given a large amount of historical data, the forecasts of ARMAX are better than the other linear models. (2) The linear model is weaker on foretelling peaks and bottoms regardless the amount of historical data. (3) The forecasting performance of ANN is higher than the other linear models based on two sets of historical data considered in the paper. This is probably due to the fact that the ANN model is capable of catching sophisticated nonlinear integrating effects through a learning process. To sum up, the ANN method is more appropriate than the linear method for developing a forecasting model of electricity consumption. Moreover, researchers can employ either ANN or linear model to extract the important economic factors of the electricity consumption in Taiwan. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
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