Charis Ntakolia

National Technical University of Athens | NTUA · School of Naval Architecture and Marine Engineering

Today the rapid rise in the number of sensors in the fab has resulted to massive amount of raw energy-related data that has to be processed, aggregated, categorized and evaluated. Data by itself isn’t useful. The energy industry is facing the challenge of converting huge torrent of data into actionable information to drive improvements in the energ...

Obstacle detection addresses the detection of an object, of any kind, that interferes with the canonical trajectory of a subject, such as a human or an autonomous robotic agent. Prompt obstacle detection can become critical for the safety of visually impaired individuals (VII). In this context, we propose a novel methodology for obstacle detection,...

The insufficient air routes combined with the adverse weather and congestion to air sectors lead to economic, environmental and safety problems to political aviation in Europe. This situation creates negative aspects to airlines and airports, as well. Furthermore, according to recent studies over 40,000 daily flights are predicted for 2020, and the...

Visual impairment restricts everyday mobility and limits the accessibility of places, which for the non-visually impaired is taken for granted. A short walk to a close destination, such as a market or a school becomes an everyday challenge. In this chapter, we present a novel solution to this problem that can evolve into an everyday visual aid for...

The marginalization of people with disabilities, such as visually impaired individuals (VIIs), has driven scientists to take advantage of the fast growth of smart technologies and develop smart assistive systems (SASs) to bring VIIs back to social life, education and even to culture. Our research focuses on developing a human–computer interactive s...

rain storm optimization (BSO) is a swarm-intelligence clustering-based algorithm inspired by the human brainstorming process. Electromagnetism-like mechanism for global optimization (EMO) is a physics-inspired optimization algorithm. In this study we propose a novel hybrid metaheuristic evolutionary algorithm that combines aspects from both BSO and...

The COVID-19 pandemic and its accompanying restrictions have significantly impacted people’s lives globally. There is an increasing interest in examining the influence of this unprecedented situation on our mental well-being, with less attention towards the impact of the elongation of COVID-19-related measures on youth with a pre-existing psychiatr...

Unmanned Surface Vehicles (USVs) are nowadays used in various applications for security, inspection and delivery among others. To operate in dynamic and complex environments efficiently demands an optimal path planning where multiple factors should be taken into account. In this paper, the multi-objective path planning problem of USV is formulated...

Port activity is assumed to be an integral part of maritime activity. Ships are supplied with water, food, fuel, electricity, spare parts and consumables when they are berthed in ports. Therefore, the purpose of the service system is to reduce the waiting cost, from the time the ship’s arrival until its service. Delays in the system, and particular...

In this study, we present a hybrid approach of Ant Colony Optimization algorithm (ACO) with fuzzy logic and clustering methods to solve multiobjective path planning problems in the case of swarm Unmanned Surface Vehicles (USVs). This study aims to further explore the performance of the ACO algorithm by integrating fuzzy logic in order to cope with...

In this study we present a hybrid approach of ACO with fuzzy logic and clustering methods to solve multi-objective path planning problems in case of swarm USVs. This study aims to enhance the performance of ACO algorithm by integrating fuzzy logic in order to cope with the multiple contradicting objectives and generate quality solutions by in paral...

Βrainstorm Optimization (BSO) is a swarm-intelligence clustering-based algorithm inspired by the human brainstorming process. Electromagnetism-like Mechanism for global Optimization (EMO) is a physics-inspired optimization algorithm. In this study we propose a novel hybrid metaheuristic evolutionary algorithm that combines aspects from both BSO and...

Given the increased interest in smart assistive technologies and autonomous robot vehicles, path planning has emerged as one of the most researched and challenging topics in navigation. Moving to partially known or unknown environment, an assistive navigation system should be able to extract spatiotemporal information and dynamically identify objec...

Port activity is assumed to be an integral part of maritime activity. Ships are supplied with water, food, fuel, electricity, spare parts and consumables when they are berthed in Ports. Therefore, the purpose of the service system is to reduce the waiting cost, from the time the ship’s arrival until its service. Delays in the system, and particular...

The increased use of unmanned surface vehicles (USVs) to various applications in complex environments has led to the need of novel path planning approaches that can effectively address multi-objective path planning problems. Ant Colony Optimization (ACO) is a well-known and popular path search algorithm for graph-based problems that finds the short...

Since the onset of COVID-19 pandemic, concerns have been raised about the effects of the pandemic on youth with pre-existing mental health disorders. The present study aimed to explore change in emotional and behavioral symptoms (mood states) and daily behaviors during the lockdown in a clinical sample of children and adolescents in Greece. A cross...

Anterior cruciate ligament (ACL) deficient and reconstructed knees display altered biomechanics during gait. Identifying significant gait changes is important for understanding normal and ACL function and is typically performed by statistical approaches. This paper focuses on the development of an explainable machine learning (ML) empowered methodo...

Argyris Stringaris was initially included as an author in the original publication [...].

Recent studies show that the number of flights is expected to be increased significantly by 2030, leading to air traffic capacity and congestion issues in the air sectors. This challenging management of the anticipated volume of flights has emerged new derivatives and procedures from the European Union and EUROCONTROL. Aligned with the new vision o...

Knee Osteoarthritis (ΚΟΑ) is a degenerative joint disease of the knee that results from the progressive loss of cartilage. Due to KOA's multifactorial nature and the poor understanding of its pathophysiology, there is a need for reliable tools that will reduce diagnostic errors made by clinicians. The existence of public databases has facilitated t...

The global spread of COVID-19 led the World Health Organization to declare a pandemic on 11 March 2020. To decelerate this spread, countries have taken strict measures that have affected the lifestyles and economies. Various studies have focused on the identification of COVID-19’s impact on the mental health of children and adolescents via traditio...

The global spread of COVID-19 led the World Health Organization to declare a pandemic on 11 March 2020. To decelerate this spread, countries have taken strict measures that affected the lifestyle and economy. Various studies have been focused on the identification of COVID-19 impact to mental health of children and adolescents via traditional stati...

Global competition among businesses imposes a more effective and low-cost supply chain allowing firms to provide products at a desired quality, quantity, and time, with lower production costs. The latter include holding cost, ordering cost, and backorder cost. Backorder occurs when a product is temporarily unavailable or out of stock and the custom...

Advances in robotic motion and computer vision have contributed to the increased use of automated and unmanned vehicles in complex and dynamic environments for various applications. Unmanned surface vehicles (USVs) have attracted a lot of attention from scientists to consolidate the wide use of USVs in maritime transportation. However, most of the...

Objective Feature selection (FS) is a crucial and at the same time challenging processing step that aims to reduce the dimensionality of complex classification or regression problems. Various techniques have been proposed in the literature to address this challenge with emphasis to medical applications. However, each one of the existing FS algorith...

Port activity is assumed to be an integral part of maritime activity. Ships are supplied with water, food, fuel, electricity, spare parts and consumables when they are berthed in Ports. Therefore, the purpose of the service system is to reduce the waiting cost, from the time the ship’s arrival until its service. Delays in the system, and particular...

Knee Osteoarthritis (ΚΟΑ) is a degenerative joint disease of the knee that results from the progressive loss of cartilage. Due to KOA’s multifactorial nature and the poor understanding of its pathophysiology, there is a need for reliable tools that will reduce diagnostic errors made by clinicians. The existence of public databases has facilitated t...

Bone scintigraphy is a popular method for the diagnosis of bone metastasis that typically occurs when cancer cells from the primary tumor relocate to the bone. In bone scintigraphy, the whole patient's body is scanned and the generated bone scan visualization provides a valuable source of information for the evaluation of various bone-related patho...

Personalized tourist route planning (TRP) and navigation are online or real-time applications whose mathematical modeling leads to complex optimization problems. These problems are usually formulated with mathematical programming and can be described as NP hard problems. Moreover, the state-of-the-art (SOA) path search algorithms do not perform eff...

Osteoarthritis is a joint disease that commonly occurs in the knee (KOA). The continuous increase in medical data regarding KOA has triggered researchers to incorporate artificial intelligence analytics for KOA prognosis or treatment. In this study, two approaches are presented to predict the progression of knee joint space narrowing (JSN) in each...

Driven by the continuous growing demand for heating and cooling, district heating and cooling systems (DHC) play a major role in the field of energy by providing environmentally friendly solutions for citizens with significant economic impact. Taken also into account the global need for greener and smarter cities, optimization and automation of cur...

Route planning (RP) enables individuals to navigate in unfamiliar environments. Current RP methodologies generate routes that optimize criteria relevant to the traveling distance or time, whereas most of them do not consider personal preferences or needs. Also, most of the current smart wearable assistive navigation systems offer limited support to...

Bone metastasis is among the most frequent in diseases to patients suffering from metastatic cancer, such as breast or prostate cancer. A popular diagnostic method is bone scintigraphy where the whole body of the patient is scanned. However, hot spots that are presented in the scanned image can be misleading, making the accurate and reliable diagno...