John Kalomiros - Academia.edu (original) (raw)

Papers by John Kalomiros

2021 11th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)

2021 11th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)

2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS), 2019

Introducing robotics to young students is becoming very important for modern education of all lev... more Introducing robotics to young students is becoming very important for modern education of all levels. This paper presents EUROPA, an educational robot, which was developed as a handy, low-cost and extensible platform of high capabilities, suitable to bring robotics to secondary school students and beyond. It is designed as a system of easily accessible hardware and open software that can be incorporated in STEM classes of all levels in the Greek education system. The proposed robot incorporates Robot Operating System (ROS) and is based on Python which is already taught in Greek modula on informatics, similarly to other countries worldwide. We present in detail the hardware and software architecture of our robot and define its advantages among similar state-of-the-art educational robots. EUROPA platform was introduced to a class of secondary school students with robotic experience in Lego Mindstorms, and was assessed with very positive results.

2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS), 2019

A technique is proposed for the synchronization of two different sequences of chaotic oscillation... more A technique is proposed for the synchronization of two different sequences of chaotic oscillations. The technique is applied to iterated maps, like the logistic map, sharing the same map parameters. Starting from different initial conditions boldsymbolx0\boldsymbol{x}_{0}boldsymbolx0, two time-series can be synchronized by sporadically truncating the boldsymbolx\boldsymbol{x}boldsymbolx value, at the same random time intervals, in both time-series. The proposed random truncation process is performed in both chaotic sequences to the same number of boldsymbolk\boldsymbol{k}boldsymbolk bits, where boldsymbolk\boldsymbol{k}boldsymbolk is essentially lower than the nominal 64-bits of a floating-point processor. After a series of several thousand of the above common-mode truncations, the two boldsymbolxboldsymboln\boldsymbol{x}_{\boldsymbol{n}}boldsymbolxboldsymboln trajectories are driven to exact coincidence and the two time-series continue to evolve totally synchronized. The technique is applied to the design of a real-time secure communication system.

Microprocessors and Microsystems, 2008

... and frame-size limits of such a design when it is dedicated to image processing. ... utilizes... more ... and frame-size limits of such a design when it is dedicated to image processing. ... utilizes both high-level algorithm development tools and hardware description language (HDL) tools ... property (IP) cores implementing typical DSP functions or high speed communication protocols [1 ...

The design of a secure, digital communication scheme based on the chaotic iterations of the logis... more The design of a secure, digital communication scheme based on the chaotic iterations of the logistic map is proposed. A two-stage encryption technique encapsulates encrypted initial conditions in a synchronization interval and produces a keystream varying with the plaintext, at sampling clock rate. A proof of concept is provided by means of simulation. The overall coincidence probability, demonstrated by the system depends on the accuracy of the fixed-point calculations. Keywords—Digital chaotic circuit, logistic map, chaotic synchronization, secure communication, chaotic encryption.

We monitor the theoretical response of an R-L-Varactor circuit by using Multisim 7.0, at a drivin... more We monitor the theoretical response of an R-L-Varactor circuit by using Multisim 7.0, at a driving frequency f= 1MHz with high driving amphtudes. Atlow frequencies a bifurcation is observed, attributed to the large capacitance emerging from the carrier injection at reverse-bias breakdown. By inereasing driving amplitude we observe non-periodic trajectories with increasing chaotic content in a four dimensional state-space. At specific amplitudes we monitor two-dimensional tori where trajectories are periodic, like in a two-oscillatorssystem with commensurate frequencies. The scenario from quasi-periodocity to chaos is discussed by means of estabhshed tools, hke the circle map, Poincare cross sections, power and FFT spectra, correlation dimension and Kolmogorov entropy. Peak amphtudes of the monitored waveforms are shown to form an interesting pattem of well defined groups, within the resolution ofthe numerical solutions produced by the simulation.

A reconfigurable architecture for dense stereo is presented as an observation framework for a rea... more A reconfigurable architecture for dense stereo is presented as an observation framework for a real-ti me implementation of the simultaneous localization and mapping problem in robotics. The reconfigurable sen sor detects point features as corners from stereo image pairs, in order to use them at the measurement update stag e of the procedure. The main hardware blocks are a dense depth stereo accelerator, a left and right image co rner detector and a stage performing left-right consiste ncy check for the detected features. For the stereo-pro cessor stage we have implemented and tested both a localmatching method based on the Sum of Absolute Differences (SAD) and a global-matching component based on a maximum-likelihood dynamic programming technique (MLDP). The system includes a Nios II processor for data control and a USB 2.0 interface for host communication. The proposed hardware is applied as the sensor part in a real-time robotic localization and mapping experiment with the help of...

The implementation of an advanced real-time, low cost video processing platform capable of suppor... more The implementation of an advanced real-time, low cost video processing platform capable of supporting a variety of demanding robotic applications is presented. The system is designed as an open project, accessible in full detail and has the potential to grow. It is based on a FPGA plus MCU architecture, allowing the implementation of combined fixed-point and 32-bit floating-point applications with optimized resource allocation. The presented platform is optimally integrated with appropriate controllers, like video-input frame grabbers for multiple camera applications, external SDRAM, as well as USB and VGA interfaces. The processing and interfacing capabilities of the proposed system are illustrated by implementing basic feature extraction and preprocessing tasks, achieving the display of processed video frames at a rate of 30 fps with resolution 640x480. The proposed architecture is evaluated in terms of resource usage, power consumption and cost. Potential applications are also di...

Journal of Engineering Science and Technology Review

Microelectronics Journal, 2006

We present a study of surface modifications induced in a-SiC thin films grown by sputtering and s... more We present a study of surface modifications induced in a-SiC thin films grown by sputtering and subjected to ex-situ hydrogenation in a radiofrequency hydrogen glow discharge. Measurements of X-ray photoelectron spectroscopy, optical reflectivity and X-Ray diffraction lead to the conclusion that atomic hydrogen causes preferential etching of silicon from the surface and promotes the formation of a surface polycrystalline hydrogenated carbon layer with a small oxygen content. Furthermore, surface characterisation using scanning electron microscopy and atomic force microscopy shows that the surface carbon layer is grooved. The groves form angles with values very close to those of a hexagonal structure and they have an average peak-to-peak height of 20±5nm.

Materials research …, 1987

Sensors

Robots have become a popular educational tool in secondary education, introducing scientific, tec... more Robots have become a popular educational tool in secondary education, introducing scientific, technological, engineering and mathematical concepts to students all around the globe. In this paper EUROPA, an extensible, open software and open hardware robotic platform is presented focusing on teaching physics, sensors, data acquisition and robotics. EUROPA’s software infrastructure is based οn Robot Operating System (ROS). It includes easy to use interfaces for robot control and interaction with users and thus can easily be incorporated in Science, Technology, Engineering and Mathematics (STEM) and robotics classes. EUROPA was designed taking into account current trends in educational robotics. An overview of widespread robotic platforms is presented, documenting several critical parameters of interest such as their architecture, sensors, actuators and controllers, their approximate cost, etc. Finally, an introductory STEM curriculum developed for EUROPA and applied in a class of high...

Multimedia Tools and Applications

2017 9th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)

2016 5th International Conference on Modern Circuits and Systems Technologies (MOCAST), 2016

2016 IEEE International Conference on Imaging Systems and Techniques (IST), 2016

Microprocessors and Microsystems, 2016

2016 5th International Conference on Modern Circuits and Systems Technologies (MOCAST), 2016

2021 11th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)

2021 11th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)

2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS), 2019

Introducing robotics to young students is becoming very important for modern education of all lev... more Introducing robotics to young students is becoming very important for modern education of all levels. This paper presents EUROPA, an educational robot, which was developed as a handy, low-cost and extensible platform of high capabilities, suitable to bring robotics to secondary school students and beyond. It is designed as a system of easily accessible hardware and open software that can be incorporated in STEM classes of all levels in the Greek education system. The proposed robot incorporates Robot Operating System (ROS) and is based on Python which is already taught in Greek modula on informatics, similarly to other countries worldwide. We present in detail the hardware and software architecture of our robot and define its advantages among similar state-of-the-art educational robots. EUROPA platform was introduced to a class of secondary school students with robotic experience in Lego Mindstorms, and was assessed with very positive results.

2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS), 2019

A technique is proposed for the synchronization of two different sequences of chaotic oscillation... more A technique is proposed for the synchronization of two different sequences of chaotic oscillations. The technique is applied to iterated maps, like the logistic map, sharing the same map parameters. Starting from different initial conditions boldsymbolx0\boldsymbol{x}_{0}boldsymbolx0, two time-series can be synchronized by sporadically truncating the boldsymbolx\boldsymbol{x}boldsymbolx value, at the same random time intervals, in both time-series. The proposed random truncation process is performed in both chaotic sequences to the same number of boldsymbolk\boldsymbol{k}boldsymbolk bits, where boldsymbolk\boldsymbol{k}boldsymbolk is essentially lower than the nominal 64-bits of a floating-point processor. After a series of several thousand of the above common-mode truncations, the two boldsymbolxboldsymboln\boldsymbol{x}_{\boldsymbol{n}}boldsymbolxboldsymboln trajectories are driven to exact coincidence and the two time-series continue to evolve totally synchronized. The technique is applied to the design of a real-time secure communication system.

Microprocessors and Microsystems, 2008

... and frame-size limits of such a design when it is dedicated to image processing. ... utilizes... more ... and frame-size limits of such a design when it is dedicated to image processing. ... utilizes both high-level algorithm development tools and hardware description language (HDL) tools ... property (IP) cores implementing typical DSP functions or high speed communication protocols [1 ...

The design of a secure, digital communication scheme based on the chaotic iterations of the logis... more The design of a secure, digital communication scheme based on the chaotic iterations of the logistic map is proposed. A two-stage encryption technique encapsulates encrypted initial conditions in a synchronization interval and produces a keystream varying with the plaintext, at sampling clock rate. A proof of concept is provided by means of simulation. The overall coincidence probability, demonstrated by the system depends on the accuracy of the fixed-point calculations. Keywords—Digital chaotic circuit, logistic map, chaotic synchronization, secure communication, chaotic encryption.

We monitor the theoretical response of an R-L-Varactor circuit by using Multisim 7.0, at a drivin... more We monitor the theoretical response of an R-L-Varactor circuit by using Multisim 7.0, at a driving frequency f= 1MHz with high driving amphtudes. Atlow frequencies a bifurcation is observed, attributed to the large capacitance emerging from the carrier injection at reverse-bias breakdown. By inereasing driving amplitude we observe non-periodic trajectories with increasing chaotic content in a four dimensional state-space. At specific amplitudes we monitor two-dimensional tori where trajectories are periodic, like in a two-oscillatorssystem with commensurate frequencies. The scenario from quasi-periodocity to chaos is discussed by means of estabhshed tools, hke the circle map, Poincare cross sections, power and FFT spectra, correlation dimension and Kolmogorov entropy. Peak amphtudes of the monitored waveforms are shown to form an interesting pattem of well defined groups, within the resolution ofthe numerical solutions produced by the simulation.

A reconfigurable architecture for dense stereo is presented as an observation framework for a rea... more A reconfigurable architecture for dense stereo is presented as an observation framework for a real-ti me implementation of the simultaneous localization and mapping problem in robotics. The reconfigurable sen sor detects point features as corners from stereo image pairs, in order to use them at the measurement update stag e of the procedure. The main hardware blocks are a dense depth stereo accelerator, a left and right image co rner detector and a stage performing left-right consiste ncy check for the detected features. For the stereo-pro cessor stage we have implemented and tested both a localmatching method based on the Sum of Absolute Differences (SAD) and a global-matching component based on a maximum-likelihood dynamic programming technique (MLDP). The system includes a Nios II processor for data control and a USB 2.0 interface for host communication. The proposed hardware is applied as the sensor part in a real-time robotic localization and mapping experiment with the help of...

The implementation of an advanced real-time, low cost video processing platform capable of suppor... more The implementation of an advanced real-time, low cost video processing platform capable of supporting a variety of demanding robotic applications is presented. The system is designed as an open project, accessible in full detail and has the potential to grow. It is based on a FPGA plus MCU architecture, allowing the implementation of combined fixed-point and 32-bit floating-point applications with optimized resource allocation. The presented platform is optimally integrated with appropriate controllers, like video-input frame grabbers for multiple camera applications, external SDRAM, as well as USB and VGA interfaces. The processing and interfacing capabilities of the proposed system are illustrated by implementing basic feature extraction and preprocessing tasks, achieving the display of processed video frames at a rate of 30 fps with resolution 640x480. The proposed architecture is evaluated in terms of resource usage, power consumption and cost. Potential applications are also di...

Journal of Engineering Science and Technology Review

Microelectronics Journal, 2006

We present a study of surface modifications induced in a-SiC thin films grown by sputtering and s... more We present a study of surface modifications induced in a-SiC thin films grown by sputtering and subjected to ex-situ hydrogenation in a radiofrequency hydrogen glow discharge. Measurements of X-ray photoelectron spectroscopy, optical reflectivity and X-Ray diffraction lead to the conclusion that atomic hydrogen causes preferential etching of silicon from the surface and promotes the formation of a surface polycrystalline hydrogenated carbon layer with a small oxygen content. Furthermore, surface characterisation using scanning electron microscopy and atomic force microscopy shows that the surface carbon layer is grooved. The groves form angles with values very close to those of a hexagonal structure and they have an average peak-to-peak height of 20±5nm.

Materials research …, 1987

Sensors

Robots have become a popular educational tool in secondary education, introducing scientific, tec... more Robots have become a popular educational tool in secondary education, introducing scientific, technological, engineering and mathematical concepts to students all around the globe. In this paper EUROPA, an extensible, open software and open hardware robotic platform is presented focusing on teaching physics, sensors, data acquisition and robotics. EUROPA’s software infrastructure is based οn Robot Operating System (ROS). It includes easy to use interfaces for robot control and interaction with users and thus can easily be incorporated in Science, Technology, Engineering and Mathematics (STEM) and robotics classes. EUROPA was designed taking into account current trends in educational robotics. An overview of widespread robotic platforms is presented, documenting several critical parameters of interest such as their architecture, sensors, actuators and controllers, their approximate cost, etc. Finally, an introductory STEM curriculum developed for EUROPA and applied in a class of high...

Multimedia Tools and Applications

2017 9th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)

2016 5th International Conference on Modern Circuits and Systems Technologies (MOCAST), 2016

2016 IEEE International Conference on Imaging Systems and Techniques (IST), 2016

Microprocessors and Microsystems, 2016

2016 5th International Conference on Modern Circuits and Systems Technologies (MOCAST), 2016