Maria S. PapadopoulouInternational Hellenic University · Department of Information and Electronic Engineering
Maria S. Papadopoulou
Physicist (B.Sc.)-Electronic Engineer (M.Sc., Ph.D.)
About
51
Publications
10,867
Reads
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542
Citations
Citations since 2017
Introduction
Non-linear Electronic Circuits, WSNs and IoT Networks, Cryptography, RF Energy Harvesting, Microcontrollers
Additional affiliations
November 2019 - present
March 2006 - June 2019
January 2006 - present
Education
September 1996 - September 2001
Publications
Publications (51)
Radio-frequency (RF) energy harvesting (EH) is emerging as a reliable and constantly available free energy source. The primary factor determining whether this energy can be utilized is how efficiently it can be collected. In this work, an RF EH system is presented. More particularly, we designed a dual-band RF to DC rectifier circuit at sub-6 GHz i...
The discipline of Deep Learning has been recognized for its strong computational tools, which have been extensively used in data and signal processing, with innumerable promising results. Among the many commercial applications of Deep Learning, Music Signal Processing has received an increasing amount of attention over the last decade. This work re...
The need for electronic devices usage has risen significantly over the years. This has in turn generated greater demands for electricity and in addition for green energy sources. These include Radio-Frequency (RF) energy harvesting. In this concept we design a rectifier circuit for RF to DC conversion suitable for operation at sub-6 GHz 5G bands. S...
In this paper, we study a three-dimensional Lorenz system that demonstrates chaotic behavior. We present the state equations and mathematical analysis of the system. We use a system-design platform, like LabView, to study and analyze main information properties, such as chaotic attractors, time series, bifurcation diagram, and dynamic behavior of t...
The exigency for continuous use of electrical devices has created greater demands for electricity along with more efficient transmission techniques. Energy from natural resources can be solar, thermal, vibration, friction, or Radio Frequencies (RF) signals. This state-of-the-art work provides a summary of RF energy harvesting techniques and can be...
Frequency Selective Surfaces (FSSs) have become increasingly popular during the last years due to their combined characteristics, which meet, in general, the requirements of the next-generation wireless communication networks. In this work, a cross-platform design framework for FSS structures is presented and evaluated by utilizing a recently intro...
Swarm Intelligence (SI) Algorithms imitate the collective behavior of various swarms or
groups in nature. In this work, three representative examples of SI algorithms have been selected and thoroughly described, namely the Grey Wolf Optimizer (GWO), the Whale Optimization Algorithm (WOA), and the Salp Swarm Algorithm (SSA). Firstly, the selected SI...
Radio Frequency (RF) energy harvesting has been emerged as a potentially reliable method to replace the costly and difficult to maintain source of low-power wireless sensor networks. A plethora of dual-band rectifier designs has been proposed in the literature operating in various frequency bands. In this paper, a triple-band RF-to-DC rectifier tha...
A triple-band single-layer rectenna for outdoor RF energy applications is introduced in this paper. The proposed rectenna operates in the frequency bands of LoRa, GSM-1800, and UMTS-2100 networks. To obtain a triple-band operation, a modified E-shaped patch antenna is used. The receiving module (antenna) of the rectenna system is optimized in terms...
Radio frequency energy harvesting has attracted considerable interest as a technique of enabling self-powered wireless networks. This technique faces several challenges, such as the receiving and the rectifying modules of a rectenna system. Multiband antennas provide several comparative advantages against the goal of maximizing the amount of energy...
Nowadays electricity is undoubtedly one of the most important goods. Over the years, the dependence of people on electrical devices has sharply increased. The need for continuous use of these devices has created greater demand for electricity as well as more efficient transmission techniques. Environmental energy scavenging, as well as wireless tra...
Agriculture 4.0, as the future of farming technology, includes several key enabling technologies towards sustainable agriculture. The use of state-of-the-art technologies, such as the Internet of Things, transform traditional cultivation practices, like irrigation, to modern solutions of precision agriculture. In this paper, we present in detail th...
The design of a wireless sensor network (WSN) has several key points to consider. Power management and battery charging, especially when is applied in a harsh environment, are crucial parameters. In this paper, we present an RF energy harvesting system that converts ambient AC electromagnetic energy into DC voltage, which is applicable to supply lo...
As the power requirements of electronic systems
in wireless sensor networks are progressively reducing, radio
frequency (RF) energy harvesting (EH) technique is becoming
increasingly interesting during the last years. In this paper,
we design and optimize a modified printed bow-tie antenna,
operating in the frequency band of 5G NR mobile communicat...
Radio Frequency Energy Harvesting (RF EH) is
an alternative, yet well-promising technique to deliver power
in electronic circuits of wireless sensor networks that require
small amounts of energy. The design of the receiving module
(antenna) in RF EH systems is a demanding and, in most cases,
a complex task. As a result, an optimization method is of...
Radio Frequency (RF) energy harvesting is emerging as a potentially reliable method to replace the costly and, difficult to maintain, source of low-power wireless sensors networks. In this paper, a dual-band RF-to-DC rectifier, that operates at LoRaWAN and GSM-900 cellular communication frequency bands, is presented. The system is composed of an im...
Radio Frequency (RF) energy harvesting is emerging as a potentially reliable method to replace the costly and, difficult to maintain, source of low-power wireless sensors networks. In this paper, a dual-band RF-to-DC rectifier, that operates at LoRaWAN and GSM-900 cellular communication frequency bands, is presented. The system is composed of an im...
Radio Frequency Energy Harvesting (RF EH) is
an alternative, yet well-promising technique to deliver power
in electronic circuits of wireless sensor networks that require
small amounts of energy. The design of the receiving module
(antenna) in RF EH systems is a demanding and, in most cases,
a complex task. As a result, an optimization method is of...
Internet of Things (IoT) and Unmanned Aerial Vehicles (UAVs) are two hot technologies utilized in cultivation fields, which transform traditional farming practices into a new era of precision agriculture. In this paper, we perform a survey of the last research on IoT and UAV technology applied in agriculture. We describe the main principles of IoT...
Water scarcity and desertification are considered to be among the greatest challenges of humanity over the coming decades. Worldwide, agriculture accounts to 69% of total water usage, while industry accounts for 23%, and urban use to 8%. In Greece, a rural development model and poor farming practices have resulted in an overwhelming 83% of total wa...
In this thesis, both theoretically and experimentally, the dynamic behaviour of unidirectional and bidirectional coupled non-linear, high order circuits is studied.
Firstly, we presented the dynamics of a 4th order nonlinear, autonomous circuit with two active elements, one nonlinear resistor RN and one linear negative conductance Gn. Using the cap...
It is generally difficult to synchronize a ring network that features chaotic behaviour, especially if the system's order is too large. In this paper, we consider a ring network of three identical nonlinear and non-autonomous circuits of fourth order, which are bidirectionally coupled through three coupling linear resistances R C . We present simul...
In this paper, we have studied the dynamics of two identical resistively coupled Chua's canonical circuits and have found that it is strongly affected by initial conditions, coupling strength and the presence of coexisting attractors. Depending on the coupling variable, chaotic synchronization has been observed both numerically and experimentally....
The experimental study of in-out intermittency during the incomplete synchronization of two coupled, nonlinear, autonomous, fourth-order, chaotic, circuits is reported. The two circuits are unidirectionally coupled via a linear resistor. The dependence of laminar lengths, on the deviation of the control parameter from its critical value, and the me...
In this paper, theoretical and experimental investigations of chaos synchronization and its application to chaotic data transmission in a communication scheme with two identical nonlinear circuits are presented. The conditions for chaos synchronization and its application as a secure communication system based on two 4th order non-autonomous chaoti...
Chaos synchronization of two identical, bidirectionally and unidirectionally coupled, non-autonomous circuits are presented. A secure communication scheme based on two unidirectionally coupled circuits is proposed. Information is embedded in a chaotic carrier by using chaotic masking technique [1].
We study the case of hyperchaotic synchronization of two identical, linearly coupled, four-dimensional chaotic systems. Individual system contains one nonlinear element, with a double-break, piecewise-linear and symmetrical v-i characteristic, and one negative conductance. Using the capacitance C 1 as the control parameter, we have observed periodi...
We study the complex dynamics of an autonomous, nonlinear circuit. The system consists of a nonlinear element, with a double-break, piecewiselinear and symmetrical v-i characteristic, a negative conductance, two capacitances, two inductances and two resistances. Using the capacitances C 1 , and C 2 as the control parameters, we have observed variou...
This paper studies and compares two non-adaptive synchronization methods of identical chaotic circuits, both theoretically and experimentally. More particularly, bidirectional and unidirectional synchronization of two autonomous nonlinear circuits are studied. Each circuit is described by a set of four first order differential equations, while the...
In this paper a novel non-autonomous 4 th order chaotic oscillator was investigated. This oscillator consists of a nonlinear resistance R N and a negative conductance G n . We have studied the dynamics of the circuit for various values of the input sinusoidal signal v s (t) in the low frequency area, both theoretically and experimentally. We have d...
In this paper the dynamic behavior of a fourth order nonlinear circuit has been studied. The circuit consists of a N-type nonlinear resistor RN, a negative conductance Gn and a sinusoidal generator vs (t). The theoretical and experimental phase portraits and spectrums are been presented, for various values of the amplitude of the input signal, in t...
In this paper a 4 th order, nonlinear and non-autonomous electric circuit has been studied. We have investigated the low frequency response of the circuit, both theoretically and experimentally. The circuit is based on the 3 rd order Chua's canonical circuit and is driven by a sinusoidal voltage source. We have studied the dynamics of the circuit f...
In this paper we have studied the case of chaotic synchronization of two identical, mutually coupled, non linear, 4 th order autonomous electric circuits. Each circuit contains one linear negative conductance G and one non linear resistor R N with a symmetrical piecewise-linear υ-i characteristic. Using the capacitances C 1 and C 2 as the control p...
In this paper we have studied an autonomous circuit. It is a fourth order circuit with a nonlinear resistor of N-type v-i characteristic. The control parameters are the capacitance C1, which is parallel to the nonlinear element, and the resistor R1, which couples the linear conductance with the nonlinear resistor. We have observed the system's depe...
In this paper we have studied a nonlinear electric circuit. It is a fourth-order, non driven circuit, which contains two active elements, one linear negative conductance and one non linear resistor. The coupling resistor between the negative conductance and the nonlinear element serves as the control parameter. We have observed that depending on th...
We have studied an autonomous 4th order circuit, which exhibits sensitive dependence on initial conditions. The circuit contains a non linear resistor RN of N-type. We have observed the dynamics of the non linear circuit for various values of its parameters. A diversity of phenomena has been detected, such as antimonotonicity, period doubling route...
We have studied the case of chaotic synchronization of two identical nonlinear autonomous electric circuits, which are mutually (bidirectionally) coupled via a linear resistor RC. The two circuits can be either υC1-coupled or υC2-coupled. Both, experimental and simulation results, have shown that chaotic synchronization is possible only in the case...
In this paper we have studied the dynamics of a 4th order, non driven electric circuit and the bidirectional coupling of two identical circuits. Primarily, we have observed the dynamic behavior of each autonomous circuit. The regions where it exhibits periodic and chaotic phase trajectories were found by investigating the bifurcations diagrams. The...
In this paper the synchronization of two similar, mutually coupled, non-linear circuits, through linear coupling resistance R C is studied. The possibility of chaos synchronization is demonstrated. The basic parameter is the linear coupling resistance, through which we control the current flowing through the branch coupling. Both theoretical and ex...
In this paper we have studied the case of chaotic synchronization of two identical, bidirectional coupled, nonlinear, 4th order autonomous electric circuits. Each circuit contains one linear negative conductance G and one nonlinear resistor RN with a
piecewise-linear υ-i characteristic.
Using the capacitance C1 and C2 as the control parameters, we...
In this paper we have studied the dynamics of a non driven circuit of fourth-order. The circuit constitutes of two active elements, one linear negative conductance and one non linear resistor exhibiting a symmetrical piecewise linear v-i characteristic. The resistor R1, which couples the negative conductance and the nonlinear element, serves as the...
Projects
Projects (29)
1. Sharing & recommending publications.
2. Connecting with colleagues.
3. Seeking new collaborations.
Внедрение на нашей планете предложенного и разработанного автором источника чистой энергии-нано-энергетики Шестого экономического уклада -единственного в мире безвредного, возобновляемого, эффективного, воспроизводимого, устойчивого и дешевого источника энергии даёт возможность выжить человечеству в замкнутом пространстве тропосферы на планете Земля в условии чрезвычайного отравления атмосферы отходами производства промышленности-отходящими газами и запредельными количествами промышленных и бытовых отходов на поверхности планеты, сохранив при этом иммунитет населения, так как топливом для предложенной Кулаковым нано энергетики новой технологической парадигмы являются все отходы жизнедеятельности самого же человечества.
English has become the only international language because it is the language of science, AI, computers, and all other branches of knowledge, in addition to being the language of international trade and banking, and diplomacy. The project aims at exploring the impact of English on the competitive linguistic environments, as well as on all other languages.
The purpose of this project is to work on different aspects of English language especially on the teaching and learning of the language. The project will focus on highlighting the importance of English language as well as research on improving the process of teaching and learning English in Pakistan.
