Stelios Mitilineos

University of West Attica | TEIATH · Electrical and Electronics Engineering

The Internet of Things (IoT) is considered a promising realm of innovation and revenue generation for the forthcoming years, revolutionizing the way we interact with objects, other people and the world. With an unprecedented but realistic target of trillions of interconnected devices, the IoT calls for technological innovations that lie in the hear...

Neural map visualization (NMV) of the 8x6 neural output map of a SOCOM trained on the STL-10 benchmark dataset. Each individual neuron of the grid is represented by a synthetic image that depicts what the neuron models and which are the representations/patterns maximizing its response.

The self-organizing convolutional map (SOCOM) hybridizes convolutional neural networks, self-organizing maps, and gradient backpropagation optimization into a novel integrated unsupervised deep learning model. SOCOM structurally combines, architecturally stacks, and algorithmically fuses its deep/unsupervised learning components. The higher-level r...

Obstructive sleep apnea hypopnea syndrome (OSAHS) is a widespread chronic disease that mostly remains undetected, mainly due to the fact that it is diagnosed via polysomnography, which is a time and resource-intensive procedure. Screening the disease’s symptoms at home could be used as an alternative approach in order to alert individuals that pote...

The sleep apnea syndrome is a chronic condition that affects the quality of life and increases the risk of severe health conditions such as cardiovascular diseases. However, the prevalence of the syndrome in the general population is considered to be heavily underestimated due to the restricted number of people seeking diagnosis, with the leading c...

The most common index for diagnosing Sleep Apnea Syndrome (SAS) is the Apnea-Hypopnea Index (AHI), defined as the average count of apnea/hypopnea events per sleeping hour. Despite its broad use in automated systems for SAS severity estimation, researchers now focus on individual event time detection rather than the insufficient classification of th...

Automobiles are incorporating a vast number of automated electronic subsystems that control critical car functionalities related to safety, performance, and driving assistance. Electromagnetic compatibility is safeguarded by manufacturers but at the same time, these electronics offer a means of susceptibility to directed electromagnetic energy laun...

Abstract. In recent years the interest in adopting novel wireless Maritime data transmission technologies has peaked, given the difficulties concerning the wired communication inside a ship’s structural complexity, alongside the difficulty in its installation process and its cost. A simulation of the feasibility of wireless data transmission in shi...

The Self-Organizing Convolutional Map (SOCOM) combines convolutional neural networks, clustering via self-organizing maps, and learning through gradient backpropagation into a novel unified unsupervised deep architecture. The proposed clustering and training procedures reflect the model’s degree of integration and synergy between its constituting m...

We present a new class of wearable textile antenna and analyse their performances through an electrical study. The developed prototypes have been realized by an embroidery process and are made of conductive twisted copper/polyester yarns on a cotton substrate. These antennas aim to transfer power and data thanks to the NFC technology, so the operat...

A microwave pulse compressor (MPC) consisting of an iris, a straight waveguide section, and a T-junction can be used in order to convert a long pulse with lower power to a shorter pulse with a higher power. A significant compression gain can be achieved, provided that the system is designed precisely. The duration of the compressed pulse is proport...

A microwave pulse compressor (MPC) system formed by an inductive iris, a straight rectangular waveguide, and an H-plane T-junction is experimentally studied. The MPC design, which is based on an equivalent circuit simulation model, ensures the optimum cavity-storage gain at 1.3 GHz. A low-pressure gas discharge tube (GDT) that is placed at the side...

In the last decade, smart textiles have become very popular as a concept and have found use in many applications, such as military, electronics, automotive, and medical ones. In the medical area, smart textiles research is focused more on biomonitoring, telemedicine, rehabilitation, sport medicine or home healthcare systems.In this research, the de...

This study provides comparison of different types of conductive yarns stitched on top of the plain woven fabric via two different structures (parallel and mesh form) for electromagnetic shielding applications. Different types of structures with conductive yarns were investigated for electromagnetic shielding and reflection loss features within the...

Cultural heritage sites, apart from being the tangible link to a country's history and culture, actively contribute to the national economy, offering a foundation upon which cultural tourism can develop. This importance at the cultural and economic level, advocates for the need for preservation of cultural heritage sites for the future generations....

Efficient sound classification of potentially hazardous events using Wireless Acoustic Sensor Networks (WASNs) is considered to significantly contribute to the preservation of cultural heritage, artifacts, and architectural sights. However, classification of field-collected sound samples is considered to be a demanding task, with a dominant issue b...

Bitcoins appeared in the world in 2008 through a paper of “Shatoshi Nakamoto”, obviously a pseudonym. It became operational in the first months of 2009. Since that time more and more users “work” in order to gain the Bitcoins. That work is known as Bitcoins mining. It presupposes the accomplishment of a very big computational load. The basic idea o...

Following the rapid technology development on smart and electronic textiles, research on textile antennas has rapidly emerged during the last decade due to their numerous applications in the health and safety sectors. Integrated electronic components in textile structures enables the development of new products and services for commercial and tacti...

In this research study, knitted fabrics were produced on an E=12 gauge electronic flat bed knitting machine for the High frequency attenuation characterization in the frequency range of 1 GHz -1,5 GhZ. Conductive yarns with different linear resistances were knitted into non-conductive base fabrics made from double covered PA 6.6 core spun lycra yar...

Recently, increasing number of studies are performed on protective fabrics containing conductive yarns for electromagnetic shielding purposes. In this paper, several weft knitted fabrics were developed with conductive yarns of the same yarn count and their conductivity and electromagnetic shielding effectiveness (EMSE) were measured. The variations...

Wireless networks are facing ever-growing demands on their spectrum and infrastructure resources nowadays, as high data-rate services and applications push networks to their limits. Adaptive antennas are considered to be a key technology and one of the leading innovations for achieving highly efficient networks that maximize capacity and improve qu...

Wearable electronics have evolved from electronic components secured on the human body with straps and belts to partial electronic components integration onto textile structures. Cables and standard components defeat the purpose of the wearable approach by being bulky, rigid and especially not being able to withstand standard textile cleaning/care...

In this research study, knitted fabrics were produced on an E= 12 gauge electronic flat bed knitting machine for the High frequency attenuation characterization in the frequency range of 1 GHz-1,5 GhZ. Conductive yarns with different linear resistances were knitted into non-conductive base fabrics made from double covered PA 6.6 core spun lycra yar...

STORM is an ongoing European research project that aims at developing an integrated platform for monitoring, protecting, and managing cultural heritage sites through technical and organizational innovation. Part of the scheduled preventive actions for the protection of cultural heritage is the development of wireless acoustic sensor networks (WASNs...

Wearable electronics have evolved from electronic components secured on the human body with straps and belts to partial electronic components integration onto textile structures. Cables and standard components defeat the purpose of the wearable approach by being bulky, rigid and especially not being able to withstand standard textile cleaning/care...

Neural networks are a well established and widely used class of machine learning tools for classification and clustering that have been successfully applied to time-series analysis and prediction. On the other hand, genetic algorithms have been used in the literature for a vast range of optimisation problems ranging from electromagnetic optimisatio...

By 2020, analysts predict a global market worth over $30 billion for wearable technology [1, 2]. Wearable technology has been adapted in the fields of sports and fitness, health and medical, work safety and security, military and space, not to mention fashion. To create wearable technology appealing to the user, the end-product must be comfortable,...

Textile antennas have recently attracted significant research resources due to their potential to be used for communications and medical applications in a seamless manner. The respective research field is very active and ongoing research includes new materials and techniques for robustness, durability and credibility of designs. A series of textile...

SAVELEC (SAfe control of non cooperative Vehicles through ELECtromagnetic means) is a European research project that aims at stopping a vehicle by interfering with its Electronic Units (EUs), yet without any consequences on the passengers or any irreversible damage on the vehicle. Microwave pulse compression (MPC) systems are considered as a key el...

Physiological parameter monitoring may be useful in many different groups of the population, such as infants, elderly people, athletes, soldiers, drivers, fire-fighters, police etc. This can provide a variety of information ranging from health status to operational readiness. In this article, we focus on the case of first responders and specificall...

Monitoring areas of environmental interest by employing a wireless acoustic sensor network has been recently investigated. Although feature-rich sensor solutions have surfaced, the requirements for a flexible node from a networking and processing segmentation point of view cannot be met by commercially available systems. The hardware development pr...

Following the rapid technology development on smart and electronic textiles, research on textile antennas has rapidly emerged during the last decade due to their numerous applications in the health and safety sectors. Integrated electronic components in textile structures enables the development of new products and services for commercial and tacti...

ESOUNDMAPS is an ongoing research program that aims in developing a wireless audio sensor network (WASN) and deploying it at the surrounding environmental area of the Technological Institute of Piraeus in Attica, Greece. The proposed WASN will be used for the environmental monitoring of the area and aims to be used in the future for assessing the i...

SAVELEC (SAfe control of non cooperative Vehicles through ELECtromagnetic means) is a project funded within the 7 th Framework Program of the European Commission that aims at slowing down and possibly stopping a vehicle by interfering with some of its key Electronic Units (EUs), yet without any consequences on the passengers or any irreversible dam...

A microelectronic system for monitoring areas of environmental interest through the automated creation of soundmaps, based on data from a wireless acoustic sensor network (WASN) has been recently proposed. In this context, it has been demonstrated that compression algorithms need to be employed at sensor node level due to the increasing demand in b...

Microwave pulse compression using a waveguide cavity formed by an inductive iris and an H-plane T-junction with the auxiliary arm shorted is studied. The individual components' equivalent circuits are used to develop a back of the envelope calculation scheme, which estimates the key design choices regarding the length of the waveguide main cavity,...

Research and technology development on smart textile technology has rapidly emerged during the last decade due to their numerous applications in the health and safety sectors. Until now it had been demonstrated that it is feasible to integrate electronic components in textile structures and clothing; now, researchers are focusing their efforts on d...

The purpose of this paper is to present the idea of wearable systems to create communication between a blind woman and her guide dog in order to assist the handicapped in the bustle and hustle of the cities of today. The key concept is to use new technologies such as flexible solar panels and flexible rechargeable batteries with existing technologi...

Microwave pulse compression systems using a waveguide cavity composed by an inductive iris and an H-plane T-junction with the primary arm shorted is studied using the individual components' equivalent circuits. The equivalent circuit model of the device is studied in detail and optimized design characteristics and performance figures such as the le...

Research and technology development on textile antennas has rapidly emerged during the last decade, due to their numerous applications in health and safety sectors in combination with smart textiles technologies. Having already demonstrated that it is feasible to fully integrate electronic components in textiles, researchers are recently focusing o...

The textile technology has served in the past mainly the basic clothing requirements. The high complexity of the processes and the great diversification of the raw materials obliged the textile technologists to remain focused on the tasks of their core issues. The interaction of the textile technology with the other fields of engineering was limite...

The electrical characterization of textile materials is becoming a key engineering task since the introduction of conductive fibres and the corresponding evolution of the textile electronic circuits. Not only conductors/resistors, but also inductors and capacitors can be constructed using a combination of conductive fibres and conventional non-cond...

Microwave pulse compression using a waveguide cavity composed by an inductive iris and an H-plane T-junction with the transverse arm shorted is studied using the individual components’ equivalent circuits and transmission line theory. The equivalent circuit model of the device is studied in detail and key figures such as the length of the waveguide...

The majority of currently available wireless devices’ localization systems are based on received signal strength (RSS) measurements. The input to the localization technique is configured by the average of a number of N instantaneous RSS samples; thereupon, during simulation of such techniques, it is necessary to generate N RSS samples and calculate...

Exploring the latest advances in wearable electronics, an emerging attention for the integration of microstrip antennas in clothing is rapidly expanding. Having already demonstrated that it is feasible to fully integrate electronic components in textiles, researchers are recently focusing on deploying antenna systems that are either fully made of t...

Conformal antennas and antenna arrays (arrays) have become necessary for vehicular communications where a high degree of aerodynamic drag reduction is needed, like in avionics and ships. However, the necessity to conform to a predefined shape (e.g., of an aircraft’s nose) directly affects antenna performance since it imposes strict constraints to t...

The electromagnetic (EM) emissions recorded prior to the Athens' earthquake (EQ) of 07/09/1999 at the 10kHz band are analyzed here for the identification of possible anomalies. The magnetic field strength measurements of the Earth's electromagnetic field at the 10kHz band clearly depict a diurnal (day periodicity) variation during "quiet" periods....

The textile materials consist usually of natural or man-made polymers. The chemical structure of the polymers results in products with isolating electrical behaviour. However, in many applications the electrical conductivity of the textile materials is highly desired. There are many methods developed for attributing the electrical conductivity to t...

Wireless sensor networks (WSNs) have attracted a great deal of research interest during the last few years, with potential applications making them ideal for the development of the envisioned world of ubiquitous and pervasive computing. Energy and computational efficiency constraints are the main key issues when dealing with this type of network. T...

Wireless Sensor Networks (WSNs) have attracted a great deal of research interest during the last few years. Potential applications make them ideal for the development of the envisioned world of ubiquitous and pervasive computing. Localization is a key aspect of such networks, since the knowledge of a sensor's location is critical in order to proces...

A new position location technique is proposed, using received signal strength measurements, which can be implemented using inexpensive off-the-shelf equipment. The proposed technique is based on geometric loci construction, and overcomes the need for onsite calibration measurements or propagation prediction tools and topographical/architectural pla...

Radio Frequency Identification (RFID) is an electronic tagging technology that allows automatic objects identification at a distance, using an electromagnetic based request-and-response exchange of a predefined codeword stored in a tag. By attaching Radio Frequency (RF) tags to objects, RFID technologies enable various applications such as supply c...

Electronically steerable passive array radiator (ESPAR) antennas constitute a promising research field and are expected to play important role in future wireless communications. In this paper, a new approach in ESPAR antenna design for base station applications is proposed. A corner-plate reflector is combined with active and passive (reactively lo...

A nonparametric fusion method for extracting accurate distance measurements from low-quality sensors is proposed. The method applies to sensors with error functions that are monotonically increasing with respect to (w.r.t.) the actual value to be measured (arguments are presented on why a monotonically increasing error function is something to be e...

Radio frequency identification (RFID) systems based on passive tags are used successfully in a wide range of object identification applications. However, the increasing needs to meet new demands on applications of localization and tracking create a new field for evolution of the RFID technology. This paper presents the design, implementation, and e...

A new range-free solution based on simple RSSI measurements is presented herein. The proposed method includes a two-stage algorithm and is able to incorporate fingerprints of specific locations, when available, in order to enhance localization accuracy. The proposed algorithm requires a strategic placement of nodes in each room while being easily s...

A new low cost switched-beam antenna array suitable for 2.4 GHz ISM applications is presented in this paper. The proposed structure consists of four planar inverted-F antennas (PIFA), sharing the same ground plane, in a configuration designed for symmetrical coverage of the horizontal plane (Quad-PIFA). A custom Genetic Algorithm (GA) is used in or...

Indoor localization is considered to be a key aspect of future context-aware, ubiquitous and pervasive systems, while Wireless Sensor Networks (WSNs) are expected to constitute the critical infrastructure in order to sense and interact with the environment surrounding them. In the context of developing ambient-assisted living and aftermath crisis m...