Alireza Ejlali

Alireza Ejlali


Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

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

Representative Publications

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18 March 2024 in IEEE Access
Verified
Journal Article
Open access
AYAbolfazl Younesi
Abolfazl Younesi
MAMohsen Ansari
Mohsen Ansari
MFMohammadAmin Fazli
MohammadAmin Fazli
AEAlireza Ejlali
Alireza Ejlali
DSDR SHAFIQUE
DR SHAFIQUE
JHJörg Henkel
Jörg Henkel
In today’s digital age, Convolutional Neural Networks (CNNs), a subset of Deep Learning (DL), are widely used for various computer vision tasks such as image classification, object detection, and image segmentation. There are numerous types of CNNs designed to meet specific needs and requirements, including 1D, 2D, and 3D CNNs, as well as dilated, grouped, attention, depthwise convolutions, and NAS, among others. Each type of CNN has its unique structure and characteristics, making it suitable for specific tasks. It’s crucial to gain a thorough understanding and perform a comparative analysis of these different CNN types to understand their strengths and weaknesses. Furthermore, studying the performance, limitations, and practical applications of each type of CNN can aid in the development of new and improved architectures in the future. We also dive into the platforms and frameworks that researchers utilize for their research or development from various perspectives. Additionally, we explore the main research fields of CNN like 6D vision, generative models, and meta-learning. This survey paper provides a comprehensive examination and comparison of various CNN architectures, highlighting their architectural differences and emphasizing their respective advantages, disadvantages, applications, challenges, and future trends.

18 January 2022 in IEEE Access
Verified
Journal Article
Open access
SSSepideh Safari
Sepideh Safari
MAMohsen Ansari
Mohsen Ansari
HKHeba Khdr
Heba Khdr
PGPourya Gohari-Nazari
Pourya Gohari-Nazari
SKSina Yari Karin
Sina Yari Karin
JHJorg Henkel
Jorg Henkel
The relentless technology scaling has provided a significant increase in processor performance, but on the other hand, it has led to adverse impacts on system reliability. In particular, technology scaling increases the processor susceptibility to radiation-induced transient faults. Moreover, technology scaling with the discontinuation of Dennard scaling increases the power densities, thereby temperatures, on the chip. High temperature, in turn, accelerates transistor aging mechanisms, which may ultimately lead to permanent faults on the chip. To assure a reliable system operation, despite these potential reliability concerns, fault-tolerance techniques have emerged. Specifically, fault-tolerance techniques employ some kind of redundancies to satisfy specific reliability requirements. However, the integration of fault-tolerance techniques into real-time embedded systems complicates preserving timing constraints. As a remedy, many task mapping/scheduling policies have been proposed to consider the integration of fault-tolerance techniques and enforce both timing and reliability guarantees for real-time embedded systems. More advanced techniques aim additionally at minimizing power and energy while at the same time satisfying timing and reliability constraints. Recently, some scheduling techniques have started to tackle a new challenge, which is the temperature increase induced by employing fault-tolerance techniques. These emerging techniques aim at satisfying temperature constraints besides timing and reliability constraints. This paper provides an in-depth survey of the emerging research efforts that exploit fault-tolerance techniques while considering timing, power/energy, and temperature from the real-time embedded systems’ design perspective. In particular, the task mapping/scheduling policies for fault-tolerance real-time embedded systems are reviewed and classified according to their considered goals and constraints. Moreover, the employed fault-tolerance techniques, application models, and hardware models are considered as additional dimensions of the presented classification. Lastly, this survey gives deep insights into the main achievements and shortcomings of the existing approaches and highlights the most promising ones.

27 July 2020 in IEEE Internet of Things Journal
Verified
Journal Article
Closed access
BSBardia Safaei
Bardia Safaei
AMAmir Mahdi Hosseini Monazzah
Amir Mahdi Hosseini Monazzah
AEAlireza Ejlali
Alireza Ejlali
Energy consumption is a major challenge in IoT devices, which was aimed to be improved by employing energy-efficient Objective Functions (OF) in the structure of RPL routing protocol. Meanwhile, the majority of the existing OFs mainly perform the parent selection based on the gathered information from the routing layer. Nevertheless, based on our investigations, there exists a series of transmission operations in the MAC layer, which significantly affects the energy consumption in IoT devices. Therefore, in this paper we propose ELITE, an energy-efficient cross-layer OF, which introduces a novel routing metric, called Strobe per Packet Ratio (SPR). SPR indicates the number of transmitted strobes per packet due to Radio Duty Cycling (RDC) policies in the MAC layer. This newly defined metric, which has been designed to be coupled with asynchronous MAC protocols, could be differentiated node by node and based on the existing relative phase shift between the communicating nodes. In this regard, ELITE tries to select a path, which imposes less number of strobe transmissions to its nodes. According to the evaluation results, while ELITE could reduce the average amount of required strobes per packet by up to 25%, it can significantly improve the average amount of consumed energy in an IoT node by up to 39% compared to its counterpart OFs.

26 January 2023 in IEEE Internet of Things Journal
Verified
Journal Article
Closed access
RSRoozbeh Siyadatzadeh
Roozbeh Siyadatzadeh
FMFatemeh Mehrafrooz
Fatemeh Mehrafrooz
MAMohsen Ansari
Mohsen Ansari
BSBardia Safaei
Bardia Safaei
DSDR SHAFIQUE
DR SHAFIQUE
AEAlireza Ejlali
Alireza Ejlali
Due to the real-time requirements in several IoT applications, fog computing has emerged to overcome the long latency and other constraints of cloud computing. Due to the high probability of packet loss, energy limitation of IoT devices, and the external disturbances that may frequently occur on the fog infrastructure, the timing constraints of real-time tasks may be compromised. Therefore, the reliability of executing real-time tasks has always been a significant challenge in fog computing. In addition to the correct execution of the tasks, it is also important to execute them before their deadlines according to their real-time classification. State-of-the-art methods generally focus on the delay or functionality of tasks in fog computing systems. However, those methods do not widely focus on the reliability of tasks with real-time constraints in dynamic environments. In this article, a novel primary backup task assignment strategy based on machine learning (ReLIEF) is proposed to improve the reliability of fog-based IoT systems. To identify suitable nodes for the execution of the primary and backup tasks, ReLIEF employs a reinforcement learning (RL) approach, which has an outstanding performance in dynamic environments by establishing a balance between communication delay and workload on each fog device. Based on the simulations, our newly proposed technique has been able to reduce the amount of task dropping rate by up to 84% against the state of the art. Moreover, it is capable of balancing the workload distribution while increasing the reliability of the system by nearly 72% compared with its counterparts.

8 September 2020 in IEEE Access
Verified
Journal Article
Open access
BSBardia Safaei
Bardia Safaei
AMAliasghar Mohammadsalehi
Aliasghar Mohammadsalehi
KKKimia Talaei Khoosani
Kimia Talaei Khoosani
SZSaba Zarbaf
Saba Zarbaf
AMAmir Mahdi Hosseini Monazzah
Amir Mahdi Hosseini Monazzah
AEAlireza Ejlali
Alireza Ejlali
With the widespread use of IoT applications and the increasing trend in the number of connected smart devices, the concept of routing has become very challenging. In this regard, the IPv6 Routing Protocol for Low-power and Lossy Networks (PRL) was standardized to be adopted in IoT networks. Nevertheless, while mobile IoT domains have gained significant popularity in recent years, since RPL was fundamentally designed for stationary IoT applications, it could not well adjust with the dynamic fluctuations in mobile applications. While there have been a number of studies on tuning RPL for mobile IoT applications, but still there is a high demand for more efforts to reach a standard version of this protocol for such applications. Accordingly, in this survey, we try to conduct a precise and comprehensive experimental study on the impact of various mobility models on the performance of a mobility-aware RPL to help this process. In this regard, a complete and scrutinized survey of the mobility models has been presented to be able to fairly justify and compare the outcome results. A significant set of evaluations has been conducted via precise IoT simulation tools to monitor and compare the performance of the network and its IoT devices in mobile RPL-based IoT applications under the presence of different mobility models from different perspectives including power consumption, reliability, latency, and control packet overhead. This will pave the way for researchers in both academia and industry to be able to compare the impact of various mobility models on the functionality of RPL, and consequently to design and implement application-specific and even a standard version of this protocol, which is capable of being employed in mobile IoT applications.

1 April 2007
Verified
Conference Paper
Closed access
AEAlireza Ejlali
Alireza Ejlali
BABashir M. Al-Hashimi
Bashir M. Al-Hashimi
PRPaul Rosinger
Paul Rosinger
IMIman Miremadi
Iman Miremadi
High reliability against noise, low energy consumption and high performance are key objectives in the design of on-chip networks. Recently some researchers have considered the various trade-offs between two of these objectives. However, as we will argue later, the three design objectives should be considered jointly and simultaneously. The first aim of this paper is to analyze the impact of various error-control schemes on the simultaneous trade-off between reliability, performance and energy when voltage swing varies. We provide a detailed comparative analysis of the error-control schemes using analytical models and SPICE simulations. The second aim of this paper is to analyze the impact of noise power and time constraint on the effectiveness of error-control schemes, which have not been addressed in previous studies