Omar M. Knio

dblp:05/5889 · DBLP profile ↗
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7ranked-venue papers
0as first author
4since 2021 · last 2024
0000-0002-0973-1112ORCID · reported

Domains — the database's venue-derived domains; a paper can count in several

Systems, architecture and hardware · 4 · 2 since 2021Artificial intelligence and machine learning · 1 · 1 since 2021Graphics, computer vision, multimedia, augmented reality and games · 1Theory of computation · 1 · 1 since 2021
YearPublicationVenuePosition
2024 Stacked Transformer Models for Enhanced Wind Speed Prediction in the Red Sea
abstract
Accurate wind speed (WS) prediction in the Red Sea is essential for enhancing maritime operations, climate analysis, and monitoring ecosystems. Due to the region's complex oceanic and atmospheric patterns, this work introduces new models based on Transformer architectures to improve WS forecasting. Transformers are employed for their strength in handling sequential data and capturing time dependencies. A stacked model called StackedTrans has been developed to boost performance further and integrate multiple Transformer layers. The model's effectiveness is tested with WS data collected from ten locations across the Red Sea and evaluated using five statistical metrics. The results indicate that the StackedTrans model consistently outperforms other methods, such as LSTM, BiLSTM, GRU, BIGRU, and single Transformer models. The StackedTrans architecture performed a notable R2 score of 99.96, demonstrating its high precision in WS prediction
Mohamad Mazen Hittawe, Fouzi Harrou, Ying Sun 0002, Omar M. Knio
INDIN4
2023 Visualization and Visual Analytics Approaches for Image and Video Datasets: A Survey
abstract
Image and video data analysis has become an increasingly important research area with applications in different domains such as security surveillance, healthcare, augmented and virtual reality, video and image editing, activity analysis and recognition, synthetic content generation, distance education, telepresence, remote sensing, sports analytics, art, non-photorealistic rendering, search engines, and social media. Recent advances in Artificial Intelligence (AI) and particularly deep learning have sparked new research challenges and led to significant advancements, especially in image and video analysis. These advancements have also resulted in significant research and development in other areas such as visualization and visual analytics, and have created new opportunities for future lines of research. In this survey article, we present the current state of the art at the intersection of visualization and visual analytics, and image and video data analysis. We categorize the visualization articles included in our survey based on different taxonomies used in visualization and visual analytics research. We review these articles in terms of task requirements, tools, datasets, and application areas. We also discuss insights based on our survey results, trends and patterns, the current focus of visualization research, and opportunities for future research.
Shehzad Afzal, Sohaib Ghani, Mohamad Mazen Hittawe, Sheikh Faisal Rashid, Omar M. Knio, Markus Hadwiger, Ibrahim Hoteit
ACM Trans. Interact. Intell. Syst.5
2022 Efficient SST prediction in the Red Sea using hybrid deep learning-based approach
abstract
Prediction of Surface Sea Temperature (SST) is of great importance in seasonal forecasts in the region and beyond, mainly due to its significant role in global atmospheric circulation. On the other hand, SST predicting from given multivariate sequences using historical ocean variables is vital to investigate how SST physical phenomena generated. This paper seeks to significantly improve the prediction of Surface Sea Temperature (SST) by combining two machine learning methodologies: short-term memory networks (LSTM) added to Gaussian Process Regression (GPR). We developed a data-driven approach based on deep learning and GPR modeling to improve the prediction of SST levels in the red sea based on meteorological variables, including the hourly wind speed (WS), air temperature at 2m (T2), and relative humidity (RH) variables. The coupled GPR-LSTM model may potentially carry both flexibility and feature extraction capacity, which could describe temporal dependencies in SST time-series and improve the prediction accuracy of SST. It is necessary to indicate that these types of hybrid-based approach architectures have not used before in SST time-series prediction, so it is a new approach to deal with these types of problems. The results demonstrate a significant improvement when this hybrid model is compared to LSTM and the most frequently used ensemble learning models.
Mohamad Mazen Hittawe, Sabique Langodan, Ouadi Beya, Ibrahim Hoteit, Omar M. Knio
INDIN5
2022 Risk-Averse Stochastic Programming vs. Adaptive Robust Optimization: A Virtual Power Plant Application
abstract
This paper compares risk-averse optimization methods to address the self-scheduling and market involvement of a virtual power plant (VPP). The decision-making problem of the VPP involves uncertainty in the wind speed and electricity price forecast. We focus on two methods: risk-averse two-stage stochastic programming (SP) and two-stage adaptive robust optimization (ARO). We investigate both methods concerning formulations, uncertainty and risk, decomposition algorithms, and their computational performance. To quantify the risk in SP, we use the conditional value at risk (CVaR) because it can resemble a worst-case measure, which naturally links to ARO. We use two efficient implementations of the decomposition algorithms for SP and ARO; we assess (1) the operational results regarding first-stage decision variables, estimate of expected profit, and estimate of the CVaR of the profit and (2) their performance taking into consideration different sample sizes and risk management parameters. The results show that similar first-stage solutions are obtained depending on the risk parameterizations used in each formulation. Computationally, we identified three cases: (1) SP with a sample of 500 elements is competitive with ARO; (2) SP performance degrades comparing to the first case and ARO fails to converge in four out of five risk parameters; (3) SP fails to converge, whereas ARO converges in three out of five risk parameters. Overall, these performance cases depend on the combined effect of deterministic and uncertain data and risk parameters. Summary of Contribution: The work presented in this manuscript is at the intersection of operations research and computer science, which are intrinsically related with the scope and mission of IJOC. From the operations research perspective, two methodologies for optimization under uncertainty are studied: risk-averse stochastic programming and adaptive robust optimization. These methodologies are illustrated using an energy scheduling problem. The study includes a comparison from the point of view of uncertainty modeling, formulations, decomposition methods, and analysis of solutions. From the computer science perspective, a careful implementation of decomposition methods using parallelization techniques and a sample average approximation methodology was done . A detailed comparison of the computational performance of both methods is performed. Finally, the conclusions allow establishing links between two alternative methodologies in operations research: stochastic programming and robust optimization.
Ricardo M. Lima, Antonio J. Conejo, Loïc Giraldi, Olivier P. Le Maître, Ibrahim Hoteit, Omar M. Knio
INFORMS J. Comput.6
2019 The State of the Art in Visual Analysis Approaches for Ocean and Atmospheric Datasets
abstract
Abstract The analysis of ocean and atmospheric datasets offers a unique set of challenges to scientists working in different application areas. These challenges include dealing with extremely large volumes of multidimensional data, supporting interactive visual analysis, ensembles exploration and visualization, exploring model sensitivities to inputs, mesoscale ocean features analysis, predictive analytics, heterogeneity and complexity of observational data, representing uncertainty, and many more. Researchers across disciplines collaborate to address such challenges, which led to significant research and development advances in ocean and atmospheric sciences, and also in several relevant areas such as visualization and visual analytics, big data analytics, machine learning and statistics. In this report, we perform an extensive survey of research advances in the visual analysis of ocean and atmospheric datasets. First, we survey the task requirements by conducting interviews with researchers, domain experts, and end users working with these datasets on a spectrum of analytics problems in the domain of ocean and atmospheric sciences. We then discuss existing models and frameworks related to data analysis, sense‐making, and knowledge discovery for visual analytics applications. We categorize the techniques, systems, and tools presented in the literature based on the taxonomies of task requirements, interaction methods, visualization techniques, machine learning and statistical methods, evaluation methods, data types, data dimensions and size, spatial scale and application areas. We then evaluate the task requirements identified based on our interviews with domain experts in the context of categorized research based on our taxonomies, and existing models and frameworks of visual analytics to determine the extent to which they fulfill these task requirements, and identify the gaps in current research. In the last part of this report, we summarize the trends, challenges, and opportunities for future research in this area. (see http://www.acm.org/about/class/class/2012 )
Shehzad Afzal, Mohamad Mazen Hittawe, Sohaib Ghani, Tahira Jamil, Omar M. Knio, Markus Hadwiger, Kevin I.-J. Ho
Comput. Graph. Forum5
2018 Exploring the interplay of resilience and energy consumption for a task-based partial differential equations preconditioner
Francesco Rizzi, Karla Morris, Khachik Sargsyan, Paul Mycek, Cosmin Safta, Olivier P. Le Maître, Omar M. Knio, Bert J. Debusschere
Parallel Comput.7
2015 Partial Differential Equations Preconditioner Resilient to Soft and Hard Faults
abstract
We present a domain-decomposition-based pre-conditioner for the solution of partial differential equations (PDEs) that is resilient to both soft and hard faults. The algorithm is based on the following steps: first, the computational domain is split into overlapping subdomains, second, the target PDE is solved on each subdomain for sampled values of the local current boundary conditions, third, the subdomain solution samples are collected and fed into a regression step to build maps between the subdomains' boundary conditions, finally, the intersection of these maps yields the updated state at the subdomain boundaries. This reformulation allows us to recast the problem as a set of independent tasks. The implementation relies on an asynchronous server-client framework, where one or more reliable servers hold the data, while the clients ask for tasks and execute them. This framework provides resiliency to hard faults such that if a client crashes, it stops asking for work, and the servers simply distribute the work among all the other clients alive. Erroneous subdomain solves (e.g. due to soft faults) appear as corrupted data, which is either rejected if that causes a task to fail, or is seamlessly filtered out during the regression stage through a suitable noise model. Three different types of faults are modeled: hard faults modeling nodes (or clients) crashing, soft faults occurring during the communication of the tasks between server and clients, and soft faults occurring during task execution. We demonstrate the resiliency of the approach for a 2D elliptic PDE, and explore the effect of the faults at various failure rates.
Francesco Rizzi, Karla Morris, Khachik Sargsyan, Paul Mycek, Cosmin Safta, Olivier P. Le Maître, Omar M. Knio, Bert J. Debusschere
CLUSTER7