Antonios Konstantaras

Analysing User Needs for a Unified 3D Metadata Recording and Exploitation of Cultural Heritage Monuments System

This research paper aims to address the problem of lack of a unified system for 3D documentation, promotion and exploitation of cultural heritage monuments via complete 3D data acquisition, 3D modeling and metadata recording using terrestrial laser scanners. Terrestrial laser scanning is a new fast developing technology that allows for the mapping and exact replication of the entire 3D shape of physical objects through the extraction of a very large number of points in space (point cloud) in short time periods, with great density and precision, and with no actual physical contact with the object of interest. The problem lies on the various types of hardware equipment and software systems used in the whole workflow of the 3D scanning process, including for the extraction of point clouds and the building process of the computerized 3D model development and the final products presentation. These often results in a large volume of interim and final products with little if no standardization, multiple different metadata, various user-dependent annotation requirements and vague documentation which often casts repeating a certain process impossible. This paper presents a user requirement analysis for a complete metadata recording during the whole lifecycle of a 3D product, aiming at supporting workflow history and provenance of 3D products of cultural heritage monuments.

Neuro-Fuzzy Prediction-Based Adaptive Filtering Applied to Severely Distorted Magnetic Field Recordings

This letter presents an adaptive filtering technique, based upon neuro-fuzzy prediction, to enhance magnetic field signal recordings affected by significant anomalies of magnetotelluric origin such as magnetic storms, rain, and cultural noise. A neuro-fuzzy model has been developed and trained to predict the magnetic field signal in the absence of any sizeable disturbances. Thus, at the occurrence of a significant distortion of nonmagnetotelluric origin, the neuro-fuzzy model predicts the healthy magnetic field signal in parallel to the distortion, thereby significantly reducing the latter. Testing the trained system using unseen data verifies the reliability of the model and demonstrates the effectiveness of the neuro-fuzzy prediction-based adaptive filtering method

ATD: A Multiplatform for Semiautomatic 3-D Detection of Kidneys and Their Pathology in Real Time

This research presents a novel multifunctional platform focusing on the clinical diagnosis of kidneys and their pathology (tumors, stones and cysts), using a “templates”-based technique. As a first step, specialist clinicians train the system by accurately annotating the kidneys and their abnormalities creating “3-D golden standard models.” Then, medical technicians experimentally adjust rules and parameters (stored as “templates”) for the integrated “automatic recognition framework” to achieve results which are closest to those of the clinicians. These parameters can later be used by nonexperts to achieve increased automation in the identification process. The systems functionality was tested on 20 MRI datasets (552 images), while the “automatic 3-D models” created were validated against the “3-D golden standard models.” Results are promising as they yield an average accuracy of 97.2% in successfully identifying kidneys and 96.1% of their abnormalities thus outperforming existing methods both in accuracy and in processing time needed.

Seismic-mass density-based algorithm for spatio-temporal clustering

In this research work a new hybrid approach to spatio-temporal seismic clustering is proposed. The method builds upon a novel density based clustering scheme that explicitly takes into account earthquakes magnitude during the density estimation. The new density based clustering algorithm considers both time and spatial information during cluster formation. Therefore clusters lie in a spatio-temporal space. A hierarchical agglomerative clustering algorithm acts upon the identified clusters after dropping the time information in order to come up only with the spatial description of seismic events. The approach is demonstrated using data from the vicinity of the Hellenic seismic arc in order to enable its comparison with some of the state-of-the-art distinct seismic region identification methodologies. The presented results indicate that the combination of the two clustering stages could be potentially used for an automatic definition of major seismic sources.

Soft-Computing Modelling of Seismicity in the Southern Hellenic Arc

This letter investigates the possible coalition of time intervals and patterns in seismic activity during the preparation process of consecutive sizeable seismic events (i.e., M S ges 5.9). During periods of low-level seismic activity, stress processes in the crust accumulate energy at the seismogenic area, while larger seismic events act as a decongesting mechanism that releases considerable amounts of that energy. Monthly mean seismicity rates have been introduced as a tool to monitor this energy management system and to divert this information into an adaptive neuro-fuzzy inference system. The purpose of the neuro-fuzzy model is to identify and to simulate the possible relationship between mean seismicity rates and time intervals among consecutive sizeable earthquakes. Successful training of the neuro-fuzzy model results in a real-time online processing mechanism that is capable of estimating the time interval between the latest and the next forthcoming sizeable seismic event.

3D-SYSTEK: Recording and exploiting the production workflow of 3D-models in Cultural Heritage

The diversity of contemporary technology on 3D-model digitizing and processing procedures necessitates the systematic documentation of all the involved activities. In this paper we present essential concepts and the infrastructure of 3D-SYSTEK (3DS), a system that supports the 3D-modelling provenance preservation in the Cultural Heritage (CH) domain. The proposed system provides an efficient repository and special tools for ingesting and browsing data, supporting the detailed and effective documentation. Specialists working on 3D-model production are able to record the production steps, keep track of their work and recall conditions and processing methods for reproduction. Additionally, CH scientists and researchers are able to browse, retrieve and annotate related CH data. Hence 3D-SYSTEK becomes a powerful tool in the area of 3D-model production, archiving and dissemination.

Real time visualization of dynamic magnetic fields with a nanomagnetic ferrolens

Abstract Due to advancements in nanomagnetism and latest nanomagnetic materials and devices, a new potential field has been opened up for research and applications which was not possible before. We herein propose a new research field and application for nanomagnetism for the visualization of dynamic magnetic fields in real-time. In short, Nano Magnetic Vision. A new methodology, technique and apparatus were invented and prototyped in order to demonstrate and test this new application. As an application example the visualization of the dynamic magnetic field on a transmitting antenna was chosen. Never seen before high-resolution, photos and real-time color video revealing the actual dynamic magnetic field inside a transmitting radio antenna rod has been captured for the first time. The antenna rod is fed with six hundred volts, orthogonal pulses. This unipolar signal is in the very low frequency (i.e. VLF) range. The signal combined with an extremely short electrical length of the rod, ensures the generation of a relatively strong fluctuating magnetic field, analogue to the signal transmitted, along and inside the antenna. This field is induced into a ferrolens and becomes visible in real-time within the normal human eyes frequency spectrum. The name we have given to the new observation apparatus is, SPIONs Superparamagnetic Ferrolens Microscope (SSFM), a powerful passive scientific observation tool with many other potential applications in the near future.

The quantum field of a magnet shown by a nanomagnetic ferrolens

Abstract It has been more than two hundred years since the first iron filings experiment, showing us the 2D macroscopic magnetic imprint of the field of a permanent magnet. However, latest developments in modern nanomagnetic passive direct observation devices reveal in real-time and color a more intriguing 3D dynamic and detailed image of the field of a magnet, with surprising new findings, that can change our perspective for dipole magnetism forever and lead to new research. This research is a continuation of our previous work, “Markoulakis, E., Rigakis, I., Chatzakis, J., Konstantaras, A., Antonidakis, E. Real time visualization of dynamic magnetic fields with a nanomagnetic ferrolens(2018) Journal of Magnetism and Magnetic Materials, 451, pp. 741–748. DOI: https://doi.org//10.1016/j.jmmm.2017.12.023 ” that is using a ferrolens apparatus for showing the dynamic magnetic field on a transmitting radio antenna, while this time the magnetostatic fields were under our scope and examined with the aid of the ferrolens. We are presenting experimental and photographical evidence, demonstrating the true complex 3D Euclidian geometry of the quantum field of permanent magnets that have never been seen before and the classic iron filings experiment, apart of its 2D limitations, fails to depict. An analysis of why and what these iron filings inherent limitations are, giving us an incomplete and also in some degree misguiding image of the magnetic field of a magnet is carried out, whereas, as we prove the ferrolens is free of these limitations and its far more advanced visualization capabilities is allowing it to show the quantum image with depth of field information, of the dipole field of a permanent magnet. For the first time the domain wall (i.e. Bloch or Neel wall) region of the field of a magnet is clearly made visible by the ferrolens along with what phenomenon is actually taking place there, leading to the inescapable conclusion, novel observation and experimental evidence that the field of any dipole magnet actually consists of two distinct and separate toroidal shaped 3D magnetic bubbles, each located at either side of the dipole around the exact spatial regions where the two poles of the magnet reside.

A Cost-effective Standalone Multisensory System for Energy Consumption and CO2 Emissions Control in Smart-Homes via Internet and Mobile Devices, Using a Network of Arduino Microcontrollers

Because of the global climate change, there is increasing need to control energy consumption and the rate of CO2 emissions into the atmosphere. This research presents a novel cost-effective multisensory system using a smart network of four Arduino microcontrollers to collect information from multiple sensors measuring temperature, light, humidity, dust, tilt (for earthquakes) and gas in order to control energy consumption of several household devices, using new technologies such as the Internet and smartphones. A number of electromechanical components including a colour TFT-LCD display, a DC motor, a step servomotor, boards, photoresistors, switches & LEDs, etc. are connected, to control the whole system. E Skounakis et al. A Cost-effective Standalone Multisensory System ... 320 The ability to monitor energy consumption in real time is designed to easily inform the users regarding gas release that contributes to global warming as well as to allow consumers to change their attitudes towards energy usage in the near future.

Expert knowledge-based algorithm for the dynamic discrimination of interactive natural clusters

The identification of distinct seismic regions and features’ extraction of theirs could provide valuable information towards the better understanding of the underlying physics, the generation mechanism and the behavior of the seismic phenomenon. This research paper works towards that direction and unveils the potential presence of a distinct seismic region located in between the Ionean sea and the Cretan see, extending south-east of Peloponnesus, Greece. This observation has emerged as a result of the development and application of a spatio temporal clustering algorithm based on expert knowledge upon seismic data provided by the Geodynamics Institute of Athens, and is further supported by geological observations, which have unveiled the presence of two parallel groups of underground faults beneath the newly discovered potential distinct seismic region. The overall spatio temporal clustering results throughout the Greek vicinity are also in accordance with empirical observations reported in the literature and coincide with cartographic groups of underground faults of Greece.