Seyed Ali Ghorashi

Dr. Seyed Ali Ghorashi


Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

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

Representative Publications

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1 July 2021 in Computer Networks
Verified
Journal Article
Closed access
HNHojjat Navidan
Hojjat Navidan
PMParisa Fard Moshiri
Parisa Fard Moshiri
MNMohammad Nabati
Mohammad Nabati
Reza ShahbazianReza Shahbazian
Reza Shahbazian
SGSeyed Ali Ghorashi
Seyed Ali Ghorashi
David WindridgeDavid Windridge
David Windridge

27 December 2017 in IEEE Sensors Letters
Verified
Journal Article
Closed access
ZKZahra Ezzati Khatab
Zahra Ezzati Khatab
AHAmirhosein Hajihoseini
Amirhosein Hajihoseini
SGSeyed Ali Ghorashi
Seyed Ali Ghorashi
By growing the demand for location based services in indoor environments in recent years, fingerprint based indoor localization has attracted much research interest. The fingerprint localization method works based on received signal strength (RSS) in wireless sensor networks. This method uses RSS measurements from available transmitter sensors, which are collected by a smart phone with internal sensors. In this article, we propose a novel algorithm that takes advantage of deep learning, extreme learning machines, and high level extracted features by autoencoder to improve the localization performance in the feature extraction and the classification. Furthermore, as the fingerprint database needs to be updated (due to the dynamic nature of environment), we also increase the number of training data, in order to improve the localization performance, gradually. Simulation results indicate that the proposed method provides a significant improvement in localization performance by using high level extracted features by autoencoder and increasing the number of training data.

30 October 2021 in Sensors
Verified
Journal Article
Open access
PDF file
PMParisa Fard Moshiri
Parisa Fard Moshiri
Reza ShahbazianReza Shahbazian
Reza Shahbazian
MNMohammad Nabati
Mohammad Nabati
SGSeyed Ali Ghorashi
Seyed Ali Ghorashi
The Internet of Things (IoT) has become quite popular due to advancements in Information and Communications technologies and has revolutionized the entire research area in Human Activity Recognition (HAR). For the HAR task, vision-based and sensor-based methods can present better data but at the cost of users’ inconvenience and social constraints such as privacy issues. Due to the ubiquity of WiFi devices, the use of WiFi in intelligent daily activity monitoring for elderly persons has gained popularity in modern healthcare applications. Channel State Information (CSI) as one of the characteristics of WiFi signals, can be utilized to recognize different human activities. We have employed a Raspberry Pi 4 to collect CSI data for seven different human daily activities, and converted CSI data to images and then used these images as inputs of a 2D Convolutional Neural Network (CNN) classifier. Our experiments have shown that the proposed CSI-based HAR outperforms other competitor methods including 1D-CNN, Long Short-Term Memory (LSTM), and Bi-directional LSTM, and achieves an accuracy of around 95% for seven activities.

3 June 2019 in IEEE Access
Verified
Journal Article
Open access
NBNabajeet Barman
Nabajeet Barman
EJEmmanuel Jammeh
Emmanuel Jammeh
SGSeyed Ali Ghorashi
Seyed Ali Ghorashi
MMMaria Martini
Maria Martini
Recent years have seen increasing growth and popularity of gaming services, both interactive and passive. While interactive gaming video streaming applications have received much attention, passive gaming video streaming, in-spite of its huge success and growth in recent years, has seen much less interest from the research community. For the continued growth of such services in the future, it is imperative that the end user gaming quality of experience (QoE) is estimated so that it can be controlled and maximized to ensure user acceptance. Previous quality assessment studies have shown not so satisfactory performance of existing No-reference (NR) video quality assessment (VQA) metrics. Also, due to the inherent nature and different requirements of gaming video streaming applications, as well as the fact that gaming videos are perceived differently from non-gaming content (as they are usually computer generated and contain artificial/synthetic content), there is a need for application specific light-weight, no-reference gaming video quality prediction models. In this paper, we present two NR machine learning based quality estimation models for gaming video streaming, NR-GVSQI and NR-GVSQE, using NR features such as bitrate, resolution, temporal information, etc. We evaluate their performance on different gaming video datasets and show that the proposed models outperform the current state-of-the-art no-reference metrics, while also reaching a prediction accuracy comparable to the best known full reference metric.

24 September 2022 in Expert Systems with Applications
Verified
Journal Article
Open access
MNMohammad Nabati
Mohammad Nabati
SGSeyed Ali Ghorashi
Seyed Ali Ghorashi

4 February 2020 in IEEE Sensors Letters
Verified
Journal Article
Closed access
MNMohammad Nabati
Mohammad Nabati
HNHojjat Navidan
Hojjat Navidan
Reza ShahbazianReza Shahbazian
Reza Shahbazian
SGSeyed Ali Ghorashi
Seyed Ali Ghorashi
David WindridgeDavid Windridge
David Windridge
Human-centered data collection is typically costly and implicates issues of privacy. Various solutions have been proposed in the literature to reduce this cost, such as crowd-sourced data collection, or the use of semi-supervised algorithms. However, semi-supervised algorithms require a source of unlabeled data, and crowd-sourcing methods require numbers of active participants. An alternative passive data collection modality is fingerprint-based localization. Such methods use received signal strength (RSS) or channel state information (CSI) in wireless sensor networks to localize users in indoor/outdoor environments. In this paper, we introduce a novel approach to reduce training data collection costs in fingerprint-based localization by using synthetic data. Generative adversarial networks (GANs) are used to learn the distribution of a limited sample of collected data and, following this, to produce synthetic data that can be used to augment the real collected data in order to increase overall positioning accuracy. Experimental results on a benchmark dataset show that by applying the proposed method and using a combination of 10% collected data and 90% synthetic data, we can obtain essentially similar positioning accuracy to that which would be obtained by using the full set of collected data. This means that by employing GAN-generated synthetic data, we can use 90% less real data, thereby reduce data-collection costs while achieving acceptable accuracy.