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Special Issue: Tsallis Entropy

Anastasios Anastasiadis
2012 Entropy  
One of the crucial properties of the Boltzmann-Gibbs entropy in the context of classical thermodynamics is extensivity, namely proportionality with the number of elements of the system. The Boltzmann-Gibbs entropy satisfies this prescription if the subsystems are statistically (quasi-) independent, or typically if the correlations within the system are essentially local. In such cases the energy of the system is typically extensive and the entropy is additive. In general, however, the situation
more » ... is not of this type and correlations may be far from negligible at all scales. Tsallis in 1988 introduced an entropic expression characterized by an index q which leads to a non-extensive statistics. Tsallis entropy, Sq, is the basis of the so called non-extensive statistical mechanics, which generalizes the Boltzmann-Gibbs theory. Tsallis statistics have found applications in a wide range of phenomena in diverse disciplines such as physics, chemistry, biology, medicine, economics, geophysics, etc. The focus of this special issue of Entropy was to solicit contributions that apply Tsallis entropy in various scientific fields. This special issue consists of nine regular papers, covering various aspects and applications of Tsallis non-additive entropy, and an invited review paper written by Tsallis [1] . In this review, the following aspects of Tsallis entropy are discussed: (i) Additivity versus extensivity; (ii) Probability distributions that constitute attractors in the sense of Central Limit Theorems; (iii) The analysis of paradigmatic low-dimensional nonlinear dynamical systems near the edge of chaos; and (iv) The analysis of paradigmatic long-range-interacting many-body classical Hamiltonian systems. Finally, recent as well as typical predictions, verifications and applications of these concepts in natural, artificial, and social systems, as shown through theoretical, experimental, observational and computational results are presented. In their paper, Zhang and Wu [2] propose a global multi-level thresholding method for image segmentation by applying the Tsallis entropy, as a general information theory entropy formalism, and using an artificial bee colony algorithm. They demonstrate that Tsallis entropy is superior to traditional maximum entropy thresholding, based on Shannon entropy, and that the artificial bee colony is more rapid than either genetic algorithm or particle swarm optimization. Vila, Bardera, Feixas and Sbert [3] investigate the application of three different Tsallis-based generalizations of mutual information to OPEN ACCESS
doi:10.3390/e14020174 fatcat:egsvzlpxnvcypanpjwksi5pmli

Sources of Solar Energetic Particles [article]

Loukas Vlahos, Anastasios Anastasiadis, Athanasios Papaioannou, Athanasios Kouloumvakos, Heinz Isliker
2019 arXiv   pre-print
Solar Energetic Particles (SEP) are an integral part of the physical processes related with Space Weather. We present a review for the acceleration mechanisms related to the explosive phenomena (flares and/or CMEs) inside the solar corona. For more than 40 years, the main 2D cartoon representing our understanding of the explosive phenomena inside the solar corona remained almost unchanged. The acceleration mechanisms related to solar flares and CMEs also remained unchanged and were part of the
more » ... ame cartoon. In this review, we revise the standard cartoon and present evidence from recent global MHD simulations that supports the argument that explosive phenomena will lead to the spontaneous formation of current sheets in different parts of the erupting magnetic structure. The evolution of the large scale current sheets and their fragmentation will lead to strong turbulence and turbulent reconnection during solar flares and turbulent shocks. In other words, the acceleration mechanism in flares and CME-driven shocks may be the same, and their difference will be the overall magnetic topology, the ambient plasma parameters, and the duration of the unstable driver.
arXiv:1903.08200v1 fatcat:7ekimpau7beizgoiaxx4xn5lr4

Large-scale field testing of geotechnical seismic isolation of structures using gravel-rubber mixtures

Dimitris Pitilakis, Anastasios Anastasiadis, Athanasios Vratsikidis, Anastasios Kapouniaris, Maria Rossella Massimino, Glenda Abate, Sebastiano Corsico
2021 Zenodo  
We present the results of a large-scale experimental campaign performed on the prototype structure of EuroProteas in Thessaloniki, Greece, to assess the effectiveness of gravel-rubber mixture (GRM) layers underneath shallow foundations as a means of geotechnical seismic isolation (GSI). We found that the geotechnical seismic isolation of structures is optimized by increasing the rubber content of the soil rubber mixture up to 30% per mixture weight. Although the effectiveness of the GSI systems
more » ... has been investigated numerically and in small-scale experiments, this paper seeks to fill the gap in the lack of full-scale experimental studies on this subject. Three soil pits were excavated and backfilled with GRM of different rubber content per weight to serve as foundation soil for the structure. A large number of instruments were installed on the structure, the foundation, the soil surface, and inside the gravel-rubber mixture layers beneath the foundation to fully monitor the GSI-structure systems' response in three dimensions. The experimental investigation included ambient noise, free- and forced-vibration tests. Our results showed that a geotechnical seismic isolation layer composed of a gravel-rubber mixture with 30% rubber content per weight effectively isolates the structure. Even 0.5m thickness (i.e., B/6 of the foundation width) of the GSI system is successfully cutting off practically all emitted waves at a (horizontal or vertical) distance of B/6 from the foundation. A significant reduction in the GSI-structure system's stiffness was apparent, leading to a rocking-dominant response. The rise in the system's damping and the substantial energy dissipation inside the GRM layer highlight its effectiveness as a geotechnical seismic isolation system.
doi:10.5281/zenodo.4557537 fatcat:gtnzxwdgrjgfdaezgjr47qrzwm

Electron Acceleration by Random DC Electric Fields

Anastasios Anastasiadis, Loukas Vlahos, Manolis K. Georgoulis
1997 Astrophysical Journal  
Anastasiadis & Vlahos proposed a model for (1991, 1994) the acceleration of particles (electrons and ions) by an ensemble of shock waves.  ...  Such an approach to the acceleration of energetic particles has been used in the past (see Anastasiadis & Vlahos The acceleration of particles 1991, 1994). has previously been found to be due to the presence  ... 
doi:10.1086/304757 fatcat:cnmrsvbjmvdqxosurbqfuycydu

Acceleration and Radiation Model of Particles in Solar Active Regions

Anastasios Anastasiadis
2006 AIP Conference Proceedings  
Anastasiadis et al. (1997; 2004) tried to connect the energy release process with the acceleration of electrons in solar flares, using a CA model for the energy release.  ...  In previous studies, Anastasiadis and Vlahos (1991; proposed a model for the acceleration of particles (electrons and ions) by an ensemble of shock waves, assuming that the energy is released by means  ... 
doi:10.1063/1.2347963 fatcat:gmn43rgpczg35lynhydowhymxu

Incidental giant renal oncocytoma: a case report

Anastasios Anastasiadis, Georgios Dimitriadis, Dimitrios Radopoulos
2010 Journal of Medical Case Reports  
Large renal oncocytomas are not very rare entities. To the best of our knowledge, we report one of the largest oncocytomas in the English literature. The tumor was incidentally diagnosed and, based on the preoperative clinical and radiographic findings, was therefore considered to be a renal cell carcinoma. Case presentation: A 48-year-old Caucasian diabetic man had an abdominal ultrasound for chronic abdominal discomfort, which revealed a large mass on the left kidney. An abdominal computed
more » ... ography scan revealed a contrast enhancing, well defined, heterogenous large mass (16.5 × 13.9 cm) originating from the left lower pole with cystic and solid areas. A magnetic resonance imaging scan was performed with no evidence of renal vein or caval thrombus or embolus. A radical nephrectomy was performed through a left flank intercostal incision and the pathology diagnosed renal oncocytoma. The postoperative course was uneventful and the patient was discharged six days later. Conclusion: Several reports have characterised this essentially benign renal histiotype, which represents 5% to 7% of all solid renal masses. Unfortunately, most renal oncocytomas cannot be differentiated from malignant renal cell carcinomas by clinical or radiographic criteria. Central stellate scar and a spoke-wheel pattern of feeding arteries are unreliable diagnostic signs and are of poor predictive value. These tumors are treated operatively with radical or partial nephrectomy or thermal ablation, depending on the clinical circumstances. We report on, to the best of our knowledge, the fourth largest lesion of this type of renal pathology. Figure 1 Preoperative magnetic resonance imaging (MRI) scan. T2-weighted sagittal MRI.
doi:10.1186/1752-1947-4-358 pmid:21059248 pmcid:PMC2990760 fatcat:jipht3czfjhbjbf6dmbhplpf2y

Food Traceability: A Consumer-Centric Supply Chain Approach on Sustainable Tomato

Foivos Anastasiadis, Ioanna Apostolidou, Anastasios Michailidis
2021 Foods  
Technological advances result in new traceability configurations that, however, cannot always secure transparency and food safety. Even in cases where a system guarantees transparency, the actual consumer involvement and a real consumer-based perspective cannot always be ensured. The importance of such consumer centricity is vital, since it is strongly associated with effective supply chains that properly fulfil their end-users' needs and requests. Thus, the objective of this paper was to
more » ... e the level of consumer centricity in food supply chains under a traceability system. The methodological approach employed a framework of two studies validating subsequently a similar set of variables, using initially consumers data and then supply chain actors data. The supply chain of sustainable tomato was selected to design the studies. The level of agreement between datasets suggested the level of the supply chain consumer centricity. Findings showed health, trust, quality, nutrition, and safety-related values to be significant for the consumers towards accepting a traceability system. The supply chain actors also accepted a traceability system based on the fact that their customers' needs rely on the exact same beliefs, indicating a high level of consumer centricity. The current work underlines the magnitude of consumer centricity in food supply chains and provides an easy and straightforward framework for its exploration. Key implications suggest the design of more effective supply chain and consumer-based strategies for the food industry. Policymakers could also adopt the concept of consumer centricity to further improve the food industry.
doi:10.3390/foods10030543 pmid:33808015 pmcid:PMC7999538 fatcat:d3xb4fyuynhelmgphtofliymq4

Mapping Sustainable Tomato Supply Chain in Greece: A Framework for Research

Foivos Anastasiadis, Ioanna Apostolidou, Anastasios Michailidis
2020 Foods  
Sustainable food supply chains are complex systems involving several stakeholders, processes, flow of goods/materials and information. The value generated in combination with the contradictory agendas among actors makes any groundwork for future research a challenging endeavor. Hence, an end-to-end mapping of the food supply chain under examination is a vital prerequisite for the design of a comprehensive research framework. This study exemplified such a mapping approach in the Greek
more » ... tomato supply chain, providing significant insights for an impactful research agenda. Data were obtained from secondary sectoral sources and open interviews with key players across the supply chain—covering all its main stages, i.e., production, packaging, storing, transportation, wholesaling, and retailing. The findings are summarized in three supply chain maps that illustrate the areas concerning sustainability, value chain and stakeholders. These maps synthesize a bigger picture of the supply chain that reveals the complicated interactions among its actors, the hidden bottlenecks in the flow of information and the areas that need deeper exploration. Its fundamental implication is the design of a targeted research framework, underlying the main priorities of the Greek tomato supply chain and eventually the Greek agri-food sector.
doi:10.3390/foods9050539 pmid:32357573 pmcid:PMC7278838 fatcat:kyfe2iwoc5ajtc3kkt2kvo45ii

Greek Political Language during the Economic Crisis—A Network Analytic Approach

Dimitrios Kydros, Anastasios Anastasiadis
2017 Social Networking  
Anastasiadis In Figure 2 , we used NodeXL's feature to group communities of nodes (see Section 3) in the same area.  ... 
doi:10.4236/sn.2017.62010 fatcat:annkvq2tevapbdxdhzthcogkqq

Building Vulnerability to the 2008 Ilia-Achaia Earthquake Induced Slides [chapter]

Stavroula Fotopoulou, Anastasios Anastasiadis, Kyriazis Pitilakis
2013 Landslide Science and Practice  
Macroseismic observations in the meizoseismal area of the Achaia-Ilia, Greece, M w 6.4 earthquake of 8 June, 2008, have shown that soil liquefaction occurred at a number of sites up to distances of 25 km from the causative fault. In one of these sites (SITE-I at coastal zone of Kato Achaia) the occurrence of liquefaction was extensive and was followed by lateral spreading. In another nearby site (SITE-II) only marginal liquefaction (or nonliquefaction) was observed. Following the macroseismic
more » ... servations, a geotechnical investigation was carried out at SITE-I and SITE-II which included exploratory boreholes with continuous sampling, SPT measurements, CPT soundings, surface wave measurements (SASW, MASW, ReMi) and laboratory testing. Based on the results of geotechnical investigation, the soil stratigraphy and pertinent soil properties were evaluated in the liquefaction/nonliquefaction locations. The assessment of peak ground acceleration at the area of SITE-I and SITE-II was based on attenuation relations and shaking table tests performed to simulate the observed behavior of an overturned (during the main shock), barrel-shaped, plastic, water filled container sitting on the ground surface at SITE-I. It is believed that the data presented in this paper can be used to 1) check the validity of current liquefaction susceptibility criteria/liquefaction triggering relationships, and 2) establish a well documented liquefaction case history that can be part of future liquefaction databases.
doi:10.1007/978-3-642-31427-8_28 fatcat:awrpms7uibfc3mmtk55tcqqesa

The Probabilistic Solar Particle Event foRecasting (PROSPER) Model [article]

Athanasios Papaioannou, Rami Vainio, Osku Raukunen, Piers Jiggens, Angels Aran, Mark Dierckxsens, Sotirios A. Mallios, Miikka Paassilta, Anastasios Anastasiadis
2022 arXiv   pre-print
Athanasios Papaioannou, Rami Vainio & Anastasios Anastasiadis acknowledge the International Space Science Institute and the supported International Team 441: High EneRgy sOlar partICle Events Analysis  ...  The range of scores are taken from Table 1 of Anastasiadis et al. (2017) (i.e. Probability of Detection -POD ∼50-70%, False Alarm Rate -FAR ∼30-50%).  ...  This pt was directly obtained by Table 1 of Anastasiadis et al. (2017) and corresponds to the threshold above which an SEP event would have been identified.  ... 
arXiv:2205.07325v1 fatcat:43nnzdtilfhrtd4zths5c475i4

Best practice in the treatment of nonmuscle invasive bladder cancer

Anastasios Anastasiadis, Theo M. de Reijke
2011 Therapeutic Advances in Urology  
doi:10.1177/1756287211431976 pmid:22295042 pmcid:PMC3263923 fatcat:fldeckowonfpbcpf5xofri6zzy

Dynamical complexity inDsttime series using non-extensive Tsallis entropy

Georgios Balasis, Ioannis A. Daglis, Constantinos Papadimitriou, Maria Kalimeri, Anastasios Anastasiadis, Konstantinos Eftaxias
2008 Geophysical Research Letters  
1] Nonlinearly evolving dynamical systems, such as space plasmas, generate complex fluctuations in their output signals that reflect the underlying dynamics. The non-extensive Tsallis entropy has been proposed as a measure to investigate the complexity of system dynamics. We employ this method for analyzing D st time series. The results show that Tsallis entropy can effectively detect the dissimilarity of complexity between the pre-storm activity and intense magnetic storms (D st < À150 nT),
more » ... ch is convenient for space weather applications. Citation: Balasis,
doi:10.1029/2008gl034743 fatcat:56jat7feijdarfdenniydhbnsy

Fast Deoxynivalenol Determination in Cereals Using a White Light Reflectance Spectroscopy Immunosensor

Vasileios Anastasiadis, Ioannis Raptis, Anastasios Economou, Sotirios E. Kakabakos, Panagiota S. Petrou
2020 Biosensors  
Deoxynivalenol (DON) is a mycotoxin produced by certain Fusarium species and found in a high percentage of wheat and maize grains cultured worldwide. Although not so toxic as other mycotoxins, it exhibits both chronic and acute toxicity, and therefore methods for its fast and accurate on-site determination are highly desirable. In the current work, we employ an optical immunosensor based on White Light Reflectance Spectroscopy (WLRS) for the fast and sensitive immunochemical label-free
more » ... tion of DON in wheat and maize samples. The assay is completed in 12 min and has a quantification limit of 2.5 ng/mL in buffer corresponding to 125 μg/kg in whole grain which is lower than the maximum allowable concentrations set by the regulatory authorities for grains intended for human consumption. Several extraction protocols have been compared, and the highest recovery (>90%) was achieved employing distilled water. In addition, identical calibration curves were received in buffer and wheat/maize extraction matrix providing the ability to analyze the grain samples using calibrators in buffer. Recoveries of DON from spiked wheat and maize grain samples ranged from 92.0(±4.0) to 105(±4.0)%. The analytical performance of the WLRS immunosensor, combined with the short analysis time and instrument portability, supports its potential for on-site determinations.
doi:10.3390/bios10110154 pmid:33113758 fatcat:e7tt5jxym5e6bolzt3djvmpi2e

Particle Acceleration and Fractional Transport in Turbulent Reconnection

Heinz Isliker, Theophilos Pisokas, Loukas Vlahos, Anastasios Anastasiadis
2017 Astrophysical Journal  
downstream will evolve and how the turbulent flows may eventually transform the turbulent shock into a new environment full of randomly moving small-scale internal shock waves and UCSs (Achterberg 1990; Anastasiadis  ... 
doi:10.3847/1538-4357/aa8ee8 fatcat:fqtk5rax4fde3jqyzb3lclr4ty
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