VLDB 2026 Research / reviewers in the wild / expert
Sajad Ahmadian
dblp:167/2049
· DBLP profile ↗
31ranked-venue papers
12as first author
22since 2021 · last 2026
0000-0002-3080-3192ORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Artificial intelligence and machine learning · 16 · 7 first-author · 10 since 2021Graphics, computer vision, multimedia, augmented reality and games · 6 · 2 first-author · 5 since 2021Databases, data management, data science and information retrieval · 4 · 4 first-author · 2 since 2021Human-computer interaction and ubiquitous computing · 4 · 1 first-author · 3 since 2021Applied, interdisciplinary, general and emerging computing · 4 · 4 since 2021Systems, architecture and hardware · 1
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Diffusion-based synthetic rating generation to alleviate data sparsity in recommender systems
Mahdi Almasi, Sajad Ahmadian, Mahmood Ahmadi |
Multim. Syst. | 2 |
| 2026 | The impact of deep data representation fusion on food recommender systems: a comparative study
Sajad Ahmadian, Mehrdad Rostami, Milad Ahmadian, Mourad Oussalah 0002 |
Multim. Tools Appl. | 1 |
| 2025 | SiSRS: Signed social recommender system using deep neural network representation learning
Abed Heshmati, Majid Meghdadi, Mohsen Afsharchi, Sajad Ahmadian |
Expert Syst. Appl. | 4 |
| 2025 | A healthy and reliable rating profile expansion approach to address data sparsity in food recommendation systemsabstractAbstract Food recommendation systems have become increasingly popular due to the proliferation of online food service websites. Accordingly, the ratings assigned by users are one of the most important resources in these systems. However, users generally express their opinions about a few foods, which results in data sparsity. Furthermore, food recommendation is a health-critical task, as recommending unhealthy foods to users may threaten their health. In this paper, we developed a novel rating profile expansion approach for food recommenders that considers both health and reliability measures. This approach enhances the efficiency of the user’s rating profile by including healthy and reliable virtual ratings. Specifically, we introduce a probabilistic rating profile evaluation technique to determine whether a profile needs to be expanded. Then, those profiles with an insufficient number of ratings are automatically expanded by adding virtual ratings obtained using the opinions of users who belong to the target user’s community. For this purpose, the users are grouped using a novel time-aware community detection algorithm based on their preferences. Moreover, a health-aware reliability measure is proposed so that only the most reliable virtual ratings are accounted for in the target user’s rating profile expansion. Therefore, the developed approach not only mitigates issues stemming from sparse data in food recommendation systems but also makes them more effective in recommending healthy foods to users. Experiments conducted on two publicly available real-world datasets demonstrated that the developed system is superior to other baseline models. Sajad Ahmadian, Mehrdad Rostami, Seyed Mohammad Jafar Jalali, Mourad Oussalah 0002, Vahid Farrahi |
Knowl. Inf. Syst. | 1 |
| 2025 | Correction: A healthy and reliable rating profile expansion approach to address data sparsity in food recommendation systems
Sajad Ahmadian, Mehrdad Rostami, Seyed Mohammad Jafar Jalali, Mourad Oussalah 0002, Vahid Farrahi |
Knowl. Inf. Syst. | 1 |
| 2025 | SiGR: a novel sign-aware graph neural network for recommender systems
Abed Heshmati, Mohsen Afsharchi, Sajad Ahmadian, Majid Meghdadi |
Multim. Syst. | 3 |
| 2024 | A novel healthy food recommendation to user groups based on a deep social community detection approachabstractExisting food recommendation models have typically suggested foods or recipes to single users. However, in reality, users may be members of a group, family, or community, requiring food recommendation systems to support the whole group. Food recommendations to groups are a more challenging task than food recommendations to individuals, as each person’s preferences in the group should be addressed before giving the recommendations. Suggesting healthy food is also important in a food recommendation system, given that unhealthy diets can lead to different diseases. To address these challenges, a new healthy group food recommendation system based on deep social community detection and user popularity is developed in this study. To this end, an innovative deep community detection approach based on feature learning and deep neural networks is developed using the calculated time-aware user similarity measure. In addition, a health-aware rate prediction measurement, which considers both group preferences and health factors, is developed. Different experiments are designed on two real-food social networks to specify the efficiency of the suggested model, and the results indicate that it enhanced the single-user and group satisfaction metrics. Mehrdad Rostami, Kamal Berahmand, Saman Forouzandeh, Sajad Ahmadian, Vahid Farrahi, Mourad Oussalah 0002 |
Neurocomputing | 4 |
| 2024 | A novel physical activity recognition approach using deep ensemble optimized transformers and reinforcement learning
Sajad Ahmadian, Mehrdad Rostami, Vahid Farrahi, Mourad Oussalah 0002 |
Neural Networks | 1 |
| 2023 | A novel healthy and time-aware food recommender system using attributed community detectionabstractFood recommendation systems aim to provide recommendations according to a user’s diet, recipes, and preferences. These systems are deemed useful for assisting users in changing their eating habits towards a healthy diet that aligns with their preferences. Most previous food recommendation systems do not consider the health and nutrition of foods, which restricts their ability to generate healthy recommendations. This paper develops a novel health-aware food recommendation system that explicitly accounts for food ingredients, food categories, and the factor of time, predicting the user’s preference through time-aware collaborative filtering and a food ingredient content-based model. Based on the user's predicted preferences and the health factor of each food, our model provides final recommendations to the target user. The performance of our model was compared to several state-of-the-art recommender systems in terms of five distinct metrics: Precision, Recall, F1, AUC, and NDCG. Experimental analysis of datasets extracted from the websites Allrecipes.com and Food.com demonstrated that our proposed food recommender system performs well compared to previous food recommendation models. Mehrdad Rostami, Vahid Farrahi, Sajad Ahmadian, Seyed Mohammad Jafar Jalali, Mourad Oussalah 0002 |
Expert Syst. Appl. | 3 |
| 2023 | RDERL: Reliable deep ensemble reinforcement learning-based recommender system
Milad Ahmadian, Sajad Ahmadian, Mahmood Ahmadi |
Knowl. Based Syst. | 2 |
| 2023 | DHSIRS: a novel deep hybrid side information-based recommender system
Amir Khani Yengikand, Majid Meghdadi, Sajad Ahmadian |
Multim. Tools Appl. | 3 |
| 2023 | Probabilistic Wind Power Forecasting Using Optimized Deep Auto-Regressive Recurrent Neural NetworksabstractWind power forecasting is very crucial for power system planning and scheduling. Deep neural networks (DNNs) are widely used in forecasting applications due to their exceptional performance. However, the DNNs’ architectural configuration has a significant impact on their performance, and the selection of proper hyper-parameters determines the success or failure of these models. Therefore, one of the challenging issues in DNNs is how to assess their hyper-parameter values effectively. Most of the previous researches in the literature have tuned the DNNs’ hyper-parameters manually, which is a weak and time-consuming task. Using optimization/evolutionary algorithms is an effective way to obtain the optimal values of DNNs’ hyper-parameters automatically. In this article, we propose a novel evolutionary algorithm that is based on the grasshopper optimization algorithm (GOA) improved by adding two evolutionary operators, opposition-based learning and chaos theory, to the optimization process. Overall, a novel probabilistic wind power forecasting model named neural GOA deep auto-regressive (NGOA-DeepAr) is proposed based on an auto-regressive recurrent neural network in which the proposed evolutionary algorithm has optimized its hyper-parameters. The performance of the proposed NGOA-DeepAr model is tested on two different datasets: One is the publicly available GEFCom-2014 dataset and the other is the Australian Energy Market Operator dataset. The prediction interval coverage probability and pinball loss for the two datasets are$[0.902, 0.320]$and$[0.933, 1.4885]$, respectively. According to the experimental findings, our proposed NGOA-DeepAr is much faster in learning and outperforms the benchmark DNNs and the other neuroevolutionary models. Parul Arora, Seyed Mohammad Jafar Jalali, Sajad Ahmadian, Bijaya K. Panigrahi, Ponnuthurai N. Suganthan, Abbas Khosravi |
IEEE Trans. Ind. Informatics | 3 |
| 2022 | An efficient cardiovascular disease detection model based on multilayer perceptron and moth-flame optimizationabstractAbstract Cardiovascular diseases are the leading cause of death in recent decades, which are increasing due to changes in people's lifestyles. Their treatment has high costs and a long treatment process. Therefore, predicting such diseases can provide care, and prevention services and treatment programs can be very useful to increase the quality of life and reduce the cost of treatment and the risk of death for patients. Various artificial neural network (ANN) techniques and machine learning (ML) algorithms can be used as efficient and reliable methods to automatically analyze and detect the hidden patterns of patient medical records data collected through medical examinations related to cardiovascular diseases. In this paper, the multilayer perceptron (MLP) neural network is employed as a supervised learning approach to detect cardiovascular diseases. Moreover, we propose a modified version of moth‐flame optimization algorithm named as MMFO which is used to achieve the optimal values of weights and biases in the MLP to speed‐up the training process and provide more accurate predictions. The effectiveness of the proposed method is assessed according to performing extensive experiments on three cardiovascular disease datasets from the UCI repository, and its performance is compared with different state‐of‐the‐art classification approaches. The results reveal that the proposed method performs better than other models in terms of all medical datasets. Sajad Ahmadian, Seyed Mohammad Jafar Jalali, Saeid Raziani, Abdolah Chalechale |
Expert Syst. J. Knowl. Eng. | 1 |
| 2022 | A reliable deep representation learning to improve trust-aware recommendation systems
Milad Ahmadian, Mahmood Ahmadi, Sajad Ahmadian |
Expert Syst. Appl. | 3 |
| 2022 | Alleviating data sparsity problem in time-aware recommender systems using a reliable rating profile enrichment approach
Sajad Ahmadian, Nima Joorabloo, Mahdi Jalili, Milad Ahmadian |
Expert Syst. Appl. | 1 |
| 2022 | X-ray image based COVID-19 detection using evolutionary deep learning approach
Seyed Mohammad Jafar Jalali, Milad Ahmadian, Sajad Ahmadian, Rachid Hedjam, Abbas Khosravi, Saeid Nahavandi |
Expert Syst. Appl. | 3 |
| 2022 | A deep learning based trust- and tag-aware recommender system
Sajad Ahmadian, Milad Ahmadian, Mahdi Jalili |
Neurocomputing | 1 |
| 2022 | Automated Deep CNN-LSTM Architecture Design for Solar Irradiance ForecastingabstractAccurate prediction of solar energy is an important issue for photovoltaic power plants to enable early participation in energy auction industries and cost-effective resource planning. This article introduces a new deep learning-based multistep ahead approach to improve the forecasting performance of global horizontal irradiance (GHI). A deep convolutional long short-term memory is used to extract optimal features for accurate prediction of the GHI. The performance of such deep neural networks directly depends on their architectures. To deal with this problem, a swarm evolutionary optimization method, called the sine-cosine algorithm, is applied and advanced to automatically optimize the network architecture. A three-phase modification model is proposed to increase the diversity of population and avoid premature convergence in the optimization mechanism. The performance of the proposed method is investigated using three datasets collected from three solar stations in the east of the United States. The experimental results demonstrate the superiority of the proposed method in comparison to other forecasting models. Seyed Mohammad Jafar Jalali, Sajad Ahmadian, Abdollah Kavousi-Fard, Abbas Khosravi, Saeid Nahavandi |
IEEE Trans. Syst. Man Cybern. Syst. | 2 |
| 2021 | Integration of Deep Sparse Autoencoder and Particle Swarm Optimization to Develop a Recommender SystemabstractRecommender systems are known as intelligent systems which have many applications in enormous domains such as social networks, e-commerce services, and online shopping. Deep neural networks have shown significant improvement in the performance of recommender systems by learning the latent features of users/items based on input data. However, it is a challenging issue to how to apply deep neural networks on different resources and how to integrate their results. In this regard, we propose a recommender system in this paper based on deep sparse autoencoder and particle swarm optimization. In particular, a deep sparse autoencoder is utilized to learn latent features based on the ratings matrix, trust relationships, and tag information. Then, particle swarm optimization is used to find the optimal weights of these latent features in calculating unknown ratings. Experiments on two datasets show the superiority of the proposed method in comparison with state of the art recommender algorithms. Milad Ahmadian, Mahmood Ahmadi, Sajad Ahmadian, Seyed Mohammad Jafar Jalali, Abbas Khosravi, Saeid Nahavandi |
SMC | 3 |
| 2021 | Deep Representation Learning using Multilayer Perceptron and Stacked Autoencoder for Recommendation SystemsabstractDeep learning-based collaborative filtering methods are studied in recommendation systems as efficient feature mapping techniques. The aim of these methods is to project the users and items to a common representation space and obtain their latent features. Although these methods have been widely used in the literature, they suffer from the limited expressiveness of Dot product function. In other words, Dot product cannot describe different impacts of various latent factors. To solve this issue, we propose a novel recommender system named Deep-MSR which exploits the multilayer perceptron (MLP) neural network and stacked auto-encoder network (SAN) to extract item latent factors and user latent factors from user-item interaction matrix. The obtained latent factors are used in the proposed rating prediction module which integrates user preferences and item features in the recommendation process. Our experiments on two well-known datasets show that our method can outperform the competitive baseline recommendation methods. Amir Khani Yengikand, Majid Meghdadi, Sajad Ahmadian, Seyed Mohammad Jafar Jalali, Abbas Khosravi, Saeid Nahavandi |
SMC | 3 |
| 2021 | A hybrid recommendation system based on profile expansion technique to alleviate cold start problem
Faryad Tahmasebi, Majid Meghdadi, Sajad Ahmadian, Khashayar Valiallahi |
Multim. Tools Appl. | 3 |
| 2021 | A Novel Evolutionary-Based Deep Convolutional Neural Network Model for Intelligent Load ForecastingabstractThe problem of electricity load forecasting has emerged as an essential topic for power systems and electricity markets seeking to minimize costs. However, this topic has a high level of complexity. Over the past few years, convolutional neural networks (CNNs) have been used to solve several complex deep learning challenges, making substantial progress in some fields and contributing to state of the art performances. Nevertheless, CNN architecture design remains a challenging problem. Moreover, designing an optimal architecture for CNNs leads to improve their performance in the prediction process. This article proposes an effective approach for the electricity load forecasting problem using a deep neuroevolution algorithm to automatically design the CNN structures using a novel modified evolutionary algorithm called enhanced grey wolf optimizer (EGWO). The architecture of CNNs and its hyperparameters are optimized by the novel discrete EGWO algorithm for enhancing its load forecasting accuracy. The proposed method is evaluated on real time data obtained from datasets of Australian Energy Market Operator in the year 2018. The simulation results demonstrated that the proposed method outperforms other compared forecasting algorithms based on different evaluation metrics. Seyed Mohammad Jafar Jalali, Sajad Ahmadian, Abbas Khosravi, Miadreza Shafie-khah, Saeid Nahavandi, João P. S. Catalão |
IEEE Trans. Ind. Informatics | 2 |
| 2020 | Neural Network Training Using a Biogeography-Based Learning Strategy
Seyed Jalaleddin Mousavirad, Seyed Mohammad Jafar Jalali, Sajad Ahmadian, Abbas Khosravi, Gerald Schaefer, Saeid Nahavandi |
ICONIP (5) | 3 |
| 2020 | A social recommender system based on reliable implicit relationships
Sajad Ahmadian, Nima Joorabloo, Mahdi Jalili, Yongli Ren, Majid Meghdadi, Mohsen Afsharchi |
Knowl. Based Syst. | 1 |
| 2019 | Evolving Artificial Neural Networks Using Butterfly Optimization Algorithm for Data Classification
Seyed Mohammad Jafar Jalali, Sajad Ahmadian, Parham M. Kebria, Abbas Khosravi, Chee Peng Lim, Saeid Nahavandi |
ICONIP (1) | 2 |
| 2019 | A novel approach based on multi-view reliability measures to alleviate data sparsity in recommender systems
Sajad Ahmadian, Mohsen Afsharchi, Majid Meghdadi |
Multim. Tools Appl. | 1 |
| 2018 | A Temporal Clustering Approach for Social Recommender SystemsabstractRecommender systems aim to suggest relevant items to users among a large number of available items. They have been successfully applied in various industries, such as e-commerce, education and digital health. On the other hand, clustering approaches can help the recommender systems to group users into appropriate clusters, which are considered as neighborhoods in prediction process. Although it is a fact that preferences of users vary over time, traditional clustering approaches fail to consider this important factor. To address this problem, a social recommender system is proposed in this paper, which is based on a temporal clustering approach. Specifically, the temporal information of ratings provided by users on items and also social information among the users are considered in the proposed method. Experimental results on a benchmark dataset show that the quality of recommendations based on the proposed method is significantly higher than the state-of-the-art methods in terms of both accuracy and coverage metrics. Sajad Ahmadian, Nima Joorabloo, Mahdi Jalili, Majid Meghdadi, Mohsen Afsharchi, Yongli Ren |
ASONAM | 1 |
| 2018 | Incorporating reliable virtual ratings into social recommendation systems
Sajad Ahmadian, Majid Meghdadi, Mohsen Afsharchi |
Appl. Intell. | 1 |
| 2018 | TCARS: Time- and Community-Aware Recommendation System
Fatemeh Rezaeimehr, Parham Moradi, Sajad Ahmadian, Nooruldeen Nasih Qader, Mahdi Jalili |
Future Gener. Comput. Syst. | 3 |
| 2018 | A social recommendation method based on an adaptive neighbor selection mechanism
Sajad Ahmadian, Majid Meghdadi, Mohsen Afsharchi |
Inf. Process. Manag. | 1 |
| 2015 | A reliability-based recommendation method to improve trust-aware recommender systems
Parham Moradi, Sajad Ahmadian |
Expert Syst. Appl. | 2 |