• A probabilistic model is proposed to evaluate the rating profiles of users. • A reliable mechanism is proposed to enhance the users’ rating profiles. • A deep sparse autoencoder is used to extract latent features of users. • An integration approach is introduced to make recommendations. Deep neural networks have been extensively employed in many applications such as natural language processing and computer vision. They have attracted a lot of attention in designing recommender systems due to their recent significant achievements. These models are mainly used in recommender systems to generate the users’ latent features according to the input data such as user-item rating and trust matrixes. However, such input data are significantly sparse leading to reduce the effectiveness of deep learning models in generating the latent features. In addition, the existing deep learning based recommendation models ignore the reliability measure in their recommendation process. To address these challenges, in this paper, a trust-aware recommendation method based on deep sparse autoencoder is proposed. Specifically, an effective probabilistic model is proposed to determine how many ratings are required for each user to produce an accurate prediction. Moreover, for enhancing the rating profiles of users with insufficient ratings, an efficient mechanism is developed based on the utilization of implicit ratings. In this mechanism, the implicit ratings are selected based on a reliability measure to guarantee their effectiveness. Then, the reliable enhanced rating profiles and trust statements are considered as the input data of deep sparse autoencoder to generate the users’ latent features. Finally, a similarity function that utilizes the generated latent features is developed to obtain similarity values between users and make recommendations. Massive experiments are carried out on two datasets to assess the effectiveness of the proposed method in comparison to the-state-of-the-art models. The results of experiments demonstrate that the proposed method can significantly beat other models in producing more accurate recommendations. 

A reliable deep representation learning to improve trust-aware recommendation systems

https://doi.org/10.1016/j.compbiomed.2022.105604

A lightweight CNN-based network on COVID-19 detection using X-ray and CT images

An advanced short-term wind power forecasting framework based on the optimized deep neural network models

Radiological methodologies, such as chest x-rays and CT, are widely employed to help diagnose and monitor COVID-19 disease. COVID-19 displays certain radiological patterns easily detectable by X-rays of the chest. Therefore, radiologists can investigate these patterns for detecting coronavirus disease. However, this task is time-consuming and needs lots of trial and error. One of the main solutions to resolve this issue is to apply intelligent techniques such as deep learning (DL) models to automatically analyze the chest X-rays. Nevertheless, fine-tuning of architecture and hyperparameters of DL models is a complex and time-consuming procedure. In this paper, we propose an effective method to detect COVID-19 disease by applying convolutional neural network (CNN) to the chest X-ray images. To improve the accuracy of the proposed method, the last Softmax CNN layer is replaced with a K -nearest neighbors (KNN) classifier which takes into account the agreement of the neighborhood labeling. Moreover, we develop a novel evolutionary algorithm by improving the basic version of competitive swarm optimizer. To this end, three powerful evolutionary operators: Cauchy Mutation (CM), Evolutionary Boundary Constraint Handling (EBCH), and tent chaotic map are incorporated into the search process of the proposed evolutionary algorithm to speed up its convergence and make an excellent balance between exploration and exploitation phases. Then, the proposed evolutionary algorithm is used to automatically achieve the optimal values of CNN's hyperparameters leading to a significant improvement in the classification accuracy of the proposed method. Comprehensive comparative results reveal that compared with current models in the literature, the proposed method performs significantly more efficient. 

https://doi.org/10.1016/j.eswa.2022.116942

X-ray image based COVID-19 detection using evolutionary deep learning approach

https://doi.org/10.1016/j.imu.2022.100941

A novel explainable COVID-19 diagnosis method by integration of feature selection with random forest

Recommender systems use intelligent algorithms to learn a user’s preferences and provide them relevant suggestions. Lack of sufficient ratings – also known as data sparsity problem – often results in poor recommendation performance. The existing recommendation methods have mainly focused on designing recommenders with high accuracy without paying much attention to the reliability of the recommendations. On the other hand, the users’ preferences may vary over time and considering the time factor in the design process is crucial, which has been largely ignored in most of the existing recommenders. To deal with these issues, a novel recommendation method is proposed in this paper which incorporates temporal reliability and confidence measures into the recommendation process. First, the effectiveness of the users’ rating is measured using a probabilistic approach and ineffective rating profiles are enriched by adding some implicit ratings to them. The quality of the predictions is evaluated using a temporal reliability measure taking into account the changes of users’ preferences over time. Then, the ratings with low reliability values are recalculated using a novel procedure, which updates the target user’s neighborhood by removing ineffective users. This leads to a temporal confidence measure that is used to update the neighborhood to provide more reliable and accurate recommendations. The superiority of the proposed method over state-of-the-art recommendation methods is shown by conducting extensive experiments on three benchmark datasets.

Alleviating data sparsity problem in time-aware recommender systems using a reliable rating profile enrichment approach

An oppositional-Cauchy based GSK evolutionary algorithm with a novel deep ensemble reinforcement learning strategy for COVID-19 diagnosis

Recommender systems (RSs) have been employed for many real-world applications including search engines, social networks, and information retrieval systems as powerful intelligent techniques for creating personalized recommendations. RSs mainly utilize different data resources such as user-item ratings, tag data, and social relationships in their recommendation process to overcome the data sparsity issue. One of the main challenges is how to integrate the results obtained by these data resources. Moreover, most of the existing RSs focus on the recommendation accuracy, and do not consider the reliability of the recommendations. To address these challenges, in this study, a reliable recommendation method is developed, which employs deep neural networks and reinforcement learning. The proposed method firstly uses a stacked denoising autoencoder model to obtain the latent features from the rating, tag, and trust data. The similarity value between each pair of users is then calculated in three different aspects according to the extracted latent features. An ensemble approach is developed by integrating the three similarities using reinforcement learning to determine the final similarity value. The ensemble similarity values are used in the rating prediction process, and the reliability of the predicted ratings is evaluated using an effective measure. Finally, a recommendation strategy is developed based on the integration of the predicted ratings and their reliability values. We evaluated the effectiveness of the proposed method by conducting numerous experiments on three datasets where the results show that the proposed method is far superior to other recommendation models in making more accurate recommendations. 

Milad Ahmadian

Papers

Alleviating data sparsity problem in time-aware recommender systems using a reliable rating profile enrichment approach

A reliable deep representation learning to improve trust-aware recommendation systems

An oppositional-Cauchy based GSK evolutionary algorithm with a novel deep ensemble reinforcement learning strategy for COVID-19 diagnosis

X-ray image based COVID-19 detection using evolutionary deep learning approach

RDERL: Reliable deep ensemble reinforcement learning-based recommender system