Christos Sevastopoulos

Mr. Christos Sevastopoulos

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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18 January 2021 in Technologies
Verified
Journal Article
Open access
PDF file
Maria KyrariniMaria Kyrarini
Maria Kyrarini
FLFotios Lygerakis
Fotios Lygerakis
ARAkilesh Rajavenkatanarayanan
Akilesh Rajavenkatanarayanan
CSChristos Sevastopoulos
Christos Sevastopoulos
HNHarish Ram Nambiappan
Harish Ram Nambiappan
FMFillia Makedon
Fillia Makedon
In recent years, with the current advancements in Robotics and Artificial Intelligence (AI), robots have the potential to support the field of healthcare. Robotic systems are often introduced in the care of the elderly, children, and persons with disabilities, in hospitals, in rehabilitation and walking assistance, and other healthcare situations. In this survey paper, the recent advances in robotic technology applied in the healthcare domain are discussed. The paper provides detailed information about state-of-the-art research in care, hospital, assistive, rehabilitation, and walking assisting robots. The paper also discusses the open challenges healthcare robots face to be integrated into our society.

10 December 2020 in Technologies
Verified
Journal Article
Open access
PDF file
Sanika DoolaniSanika Doolani
Sanika Doolani
CWCallen Wessels
Callen Wessels
VKVarun Kanal
Varun Kanal
CSChristos Sevastopoulos
Christos Sevastopoulos
AJAshish Jaiswal
Ashish Jaiswal
FMFillia Makedon
Fillia Makedon
Recently, the use of extended reality (XR) systems has been on the rise, to tackle various domains such as training, education, safety, etc. With the recent advances in augmented reality (AR), virtual reality (VR) and mixed reality (MR) technologies and ease of availability of high-end, commercially available hardware, the manufacturing industry has seen a rise in the use of advanced XR technologies to train its workforce. While several research publications exist on applications of XR in manufacturing training, a comprehensive review of recent works and applications is lacking to present a clear progress in using such advance technologies. To this end, we present a review of the current state-of-the-art of use of XR technologies in training personnel in the field of manufacturing. First, we put forth the need of XR in manufacturing. We then present several key application domains where XR is being currently applied, notably in maintenance training and in performing assembly task. We also reviewed the applications of XR in other vocational domains and how they can be leveraged in the manufacturing industry. We finally present some current barriers to XR adoption in manufacturing training and highlight the current limitations that should be considered when looking to develop and apply practical applications of XR.

29 August 2022 in IEEE Access
Verified
Journal Article
Open access
CSChristos Sevastopoulos
Christos Sevastopoulos
SKStasinos Konstantopoulos
Stasinos Konstantopoulos
Traversability illustrates the difficulty of driving through a specific region and encompasses the suitability of the terrain for traverse based on its physical properties, such as slope and roughness, surface condition, etc. In this survey we highlight the merits and limitations of all the major steps in the evolution of traversability estimation techniques, covering both non-trainable and machine-learning methods, leading up to the recent proliferation of deep learning literature. We discuss how the nascence of Deep Learning has created an opportunity for radical improvement in traversability estimation. Finally, we discuss how self-supervised learning can help satisfy deep methods’ increased need for (challenging to acquire and label) large-scale datasets.

12 January 2022 in Technologies
Verified
Journal Article
Open access
PDF file
CSChristos Sevastopoulos
Christos Sevastopoulos
SKStasinos Konstantopoulos
Stasinos Konstantopoulos
KBKeshav Balaji
Keshav Balaji
MZMohammad Zaki Zadeh
Mohammad Zaki Zadeh
FMFillia Makedon
Fillia Makedon
Training on simulation data has proven invaluable in applying machine learning in robotics. However, when looking at robot vision in particular, simulated images cannot be directly used no matter how realistic the image rendering is, as many physical parameters (temperature, humidity, wear-and-tear in time) vary and affect texture and lighting in ways that cannot be encoded in the simulation. In this article we propose a different approach for extracting value from simulated environments: although neither of the trained models can be used nor are any evaluation scores expected to be the same on simulated and physical data, the conclusions drawn from simulated experiments might be valid. If this is the case, then simulated environments can be used in early-stage experimentation with different network architectures and features. This will expedite the early development phase before moving to (harder to conduct) physical experiments in order to evaluate the most promising approaches. In order to test this idea we created two simulated environments for the Unity engine, acquired simulated visual datasets, and used them to reproduce experiments originally carried out in a physical environment. The comparison of the conclusions drawn in the physical and the simulated experiments is promising regarding the validity of our approach.

5 July 2023
Verified
Conference Paper
Open access
CSChristos Sevastopoulos
Christos Sevastopoulos
Sneh AcharyaSneh Acharya
Sneh Acharya
FMFillia Makedon
Fillia Makedon
We present a method for extracting high-level semantic information through successful landmark detection using feature fusion between RGB and depth information. We focus on the classification of specific labels (open path, humans, staircases, doorways, obstacles) in the encountered scene, which can be a fundamental source of information enhancing scene understanding, and acting towards the safe navigation of the mobile unit. Experiments are conducted using a manual wheelchair equipped with a stereo RGB-D camera that captures image instances consisting of multiple labels before fine-tuning on a pre-trained Vision Transformer (ViT).

25 April 2023 in Technologies
Verified
Journal Article
Open access
PDF file
CSChristos Sevastopoulos
Christos Sevastopoulos
MZMohammad Zaki Zadeh
Mohammad Zaki Zadeh
MTMichail Theofanidis
Michail Theofanidis
Sneh AcharyaSneh Acharya
Sneh Acharya
NPNishi Patel
Nishi Patel
FMFillia Makedon
Fillia Makedon
This article presents a method for extracting high-level semantic information through successful landmark detection using 2D RGB images. In particular, the focus is placed on the presence of particular labels (open path, humans, staircase, doorways, obstacles) in the encountered scene, which can be a fundamental source of information enhancing scene understanding and paving the path towards the safe navigation of the mobile unit. Experiments are conducted using a manual wheelchair to gather image instances from four indoor academic environments consisting of multiple labels. Afterwards, the fine-tuning of a pretrained vision transformer (ViT) is conducted, and the performance is evaluated through an ablation study versus well-established state-of-the-art deep architectures for image classification such as ResNet. Results show that the fine-tuned ViT outperforms all other deep convolutional architectures while achieving satisfactory levels of generalization.