Bahram Gharabaghi

Prof. Bahram Gharabaghi

University of Guelph
orcid

Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 May 2018 in Journal of the Air & Waste Management Association
Verified
Journal Article
Closed access
BFBrian S. Freeman
Brian S. Freeman
GTGraham Taylor
Graham Taylor
Bahram GharabaghiBahram Gharabaghi
Bahram Gharabaghi
Jesse Van Griensven ThéJesse Van Griensven Thé
Jesse Van Griensven Thé
This paper presents one of the first applications of deep learning (DL) techniques to predict air pollution time series. Air quality management relies extensively on time series data captured at air monitoring stations as the basis of identifying population exposure to airborne pollutants and determining compliance with local ambient air standards. In this paper, 8 hr averaged surface ozone (O3) concentrations were predicted using deep learning consisting of a recurrent neural network (RNN) with long short-term memory (LSTM). Hourly air quality and meteorological data were used to train and forecast values up to 72 hours with low error rates. The LSTM was able to forecast the duration of continuous O3 exceedances as well. Prior to training the network, the dataset was reviewed for missing data and outliers. Missing data were imputed using a novel technique that averaged gaps less than eight time steps with incremental steps based on first-order differences of neighboring time periods. Data were then used to train decision trees to evaluate input feature importance over different time prediction horizons. The number of features used to train the LSTM model was reduced from 25 features to 5 features, resulting in improved accuracy as measured by Mean Absolute Error (MAE). Parameter sensitivity analysis identified look-back nodes associated with the RNN proved to be a significant source of error if not aligned with the prediction horizon. Overall, MAE's less than 2 were calculated for predictions out to 72 hours. Implications: Novel deep learning techniques were used to train an 8-hour averaged ozone forecast model. Missing data and outliers within the captured data set were replaced using a new imputation method that generated calculated values closer to the expected value based on the time and season. Decision trees were used to identify input variables with the greatest importance. The methods presented in this paper allow air managers to forecast long range air pollution concentration while only monitoring key parameters and without transforming the data set in its entirety, thus allowing real time inputs and continuous prediction.

1 July 2019 in Journal of Hydrology
Verified
Journal Article
Closed access
DND. Nalley
D. Nalley
JAJ. Adamowski
J. Adamowski
Asim BiswasAsim Biswas
Asim Biswas
Bahram GharabaghiBahram Gharabaghi
Bahram Gharabaghi
WHWei Hu
Wei Hu

11 November 2024 in Remote Sensing
Verified
Journal Article
Open access
PDF file
YDYing Deng
Ying Deng
YZYue Zhang
Yue Zhang
DPDaiwei Pan
Daiwei Pan
Simon X. YangSimon X. Yang
Simon X. Yang
Bahram GharabaghiBahram Gharabaghi
Bahram Gharabaghi
This review examines the integration of remote sensing technologies and machine learning models for efficient monitoring and management of lake water quality. It critically evaluates the performance of various satellite platforms, including Landsat, Sentinel-2, MODIS, RapidEye, and Hyperion, in assessing key water quality parameters including chlorophyll-a (Chl-a), turbidity, and colored dissolved organic matter (CDOM). This review highlights the specific advantages of each satellite platform, considering factors like spatial and temporal resolution, spectral coverage, and the suitability of these platforms for different lake sizes and characteristics. In addition to remote sensing platforms, this paper explores the application of a wide range of machine learning models, from traditional linear and tree-based methods to more advanced deep learning techniques like convolutional neural networks (CNNs), recurrent neural networks (RNNs), and generative adversarial networks (GANs). These models are analyzed for their ability to handle the complexities inherent in remote sensing data, including high dimensionality, non-linear relationships, and the integration of multispectral and hyperspectral data. This review also discusses the effectiveness of these models in predicting various water quality parameters, offering insights into the most appropriate model–satellite combinations for different monitoring scenarios. Moreover, this paper identifies and discusses the key challenges associated with data quality, model interpretability, and integrating remote sensing imagery with machine learning models. It emphasizes the need for advancements in data fusion techniques, improved model generalizability, and the developing robust frameworks for integrating multi-source data. This review concludes by offering targeted recommendations for future research, highlighting the potential of interdisciplinary collaborations to enhance the application of these technologies in sustainable lake water quality management.

1 February 2013 in Journal of Hydrology
Verified
Journal Article
Closed access
NPNandana Perera
Nandana Perera
Bahram GharabaghiBahram Gharabaghi
Bahram Gharabaghi
KHKen Howard
Ken Howard

22 April 2017 in Neural Computing and Applications
Verified
Journal Article
Closed access
PDF file
ASAhmed Abdel Sattar
Ahmed Abdel Sattar
ÖEÖmer Faruk Ertuğrul
Ömer Faruk Ertuğrul
Bahram GharabaghiBahram Gharabaghi
Bahram Gharabaghi
McBean EdMcBean Ed
McBean Ed
Jiuwen CaoJiuwen Cao
Jiuwen Cao

1 May 2018 in Coastal Engineering
Verified
Journal Article
Closed access
Isa EbtehajIsa Ebtehaj
Isa Ebtehaj
HBHossein Bonakdari
Hossein Bonakdari
FMFatemeh Moradi
Fatemeh Moradi
Bahram GharabaghiBahram Gharabaghi
Bahram Gharabaghi
ZKZohreh Sheikh Khozani
Zohreh Sheikh Khozani