Announcements

This serves to announce to our valued authors based in Japan that value-added tax, or consumption tax will now be imposed on article processing fees and other service fees for all papers submitted, or resubmitted (assigned new paper IDs), effective from 15 August 2021. The change is in accordance with the Japanese "Act for Partial Revision of the Income Tax Act and Other Acts" (Act No. 9 of 2015), which includes a revision of consumption taxation on cross-border supplies of services such as digital content distribution.

For additional information from the National Tax Agency please see here ("Cross-border supplies of electronic services").

Contact: Setsuko Nishihara, MDPI Tokyo

We are pleased to announce the winner of the “Best Poster Award” sponsored by Entropy for the 11th Polish Symposium on Physics in Economy and Social Sciences (FENS2021) held on 1–3 July 2021.

• “Multibranch Multifractality and the Phase Transitions in the Trading Activity”
  by Jaroslaw Klamut, Ryszard Kutner, Tomasz Gubiec and Zbigniew R. Struzik

Empirical time series of inter-event or waiting times were investigated using a modified multifractal detrended fluctuation analysis operating on fluctuations of mean detrended dynamics. At the core of the extended multifractal analysis was the non-monotonic behavior of the generalized Hurst exponent h(q)—the fundamental exponent in the study of multifractals. The consequence of this behavior is the non-monotonic behavior of the coarse Hölder exponent α(q) leading to the multi-branchedness of the spectrum of dimensions. The Legendre–Fenchel transform was used instead of the routinely used canonical Legendre (single-branched) contact transform. The thermodynamic consequences of the multi-branched multifractality were revealed. The results were presented for the high-frequency data of the Polish stock market (Warsaw Stock Exchange) for intertrade times for KGHM—one of the most liquid stocks contained therein.

We are pleased to report that the 2020 Impact Factor of Entropy increased to 2.524 in the recent release of the Journal Citation Reports®, representing the 6th consecutive year of continuous growth. Entropy now ranks 37/85 (Q2) in the “Physics, Multidisciplinary” category.

Source: Data according to Journal Citation Reports®, 2020 release, a Clarivate Analytics product.

The 2020 citation metrics have been officially released in the Journal Citation Reports (JCR)!

We are pleased to announce that 85 MDPI journals are included, of which:

• 10 journals received their first impact factor
• 96% of journals increased their impact factor from 2019
• 32 journals (38%) ranked among the top 25% of journals, in at least one category

* Journals given their first Impact Factor in 2021

Source: 2020 Journal Impact Factors, Journal Citation Reports ® (Clarivate, 2021)

We are pleased to announce that Entropy received an increased CiteScore of 4.0 in the latest released 2020 CiteScore™ values, published by Elsevier in June 2021. Entropy now ranks 8/67 (Q1) in “Mathematical Physics”, 15/58 (Q2) in “Physics and Astronomy”, 228/693 (Q2) in “Electrical and Electronic Engineering”, and 110/329 (Q2) in “Information Systems”. For full details of the current CiteScore release, please see the journal's Source profile: https://www.scopus.com/sourceid/13715.

We would like to extend our sincerest gratitude to all of the authors, reviewers, and editors who have contributed to the journal and enabled this next big step!

We are pleased to announce that the Outstanding Paper Award, sponsored by Entropy (https://www.mdpi.com/journal/entropy), for the 4th Workshop Quantum Contextuality in Quantum Mechanics and Beyond (QCQMB) was granted to Daphne Wang at University College London. Congratulations!

• “In Search of True Contextuality in Natural Language” by Daphne Wang (joint work with Mehrnoosh Sadrzadeh, Samson Abramsky and Victor Cervantes)

Motivated by ideas of Firth and Harris, computational linguists argue that if two words often occur in the same context, they have similar meanings. Despite the successes of this idea in disambiguation tasks in NLP [1], the systematic existence of ambiguity in natural language and its shades and nuances are not challenges faced head on. Contextuality and its degrees are well studied topics in Quantum Mechanics. Here, the mathematical framework of Contextuality-by-Default (CbD) has become a useful tool when dealing with systems that are signalling and will also be convenient for natural language. Our line of research comes closest to the concept combination examples of [2]. However, as shown in [3], neither of the 23 examples of [2] are truly contextual. In our work, we did find combinations that are truly contextual for the first time. These are from a dataset of rank-2 cyclic (verb, noun) phrases constructed from [4,5], and the probabilities are tabulated from occurrences in corpora (BNC and uKWaC). More general types of systems were considered too, initially using the sheaf-theoretic approach to contextuality, but we showed that none of them are truly contextual. For our rank-2 cyclic dataset, we made use of the degrees of signalling and direct influence from M-Contextuality to find quantitative empirical evidence that the context affects ambiguous senses and meanings of nouns and verbs differently. So far, contextuality has not been found in more general systems, although nothing seems to preclude the existence of contextual examples in certain types of models.

[1] H. Schutze. Automatic Word Sense Discrimination. Computational Linguistics, 24(1): 97-123, 199

[2] P. D. Bruza, K. Kitto, B. J. Ramm, L. Sitbon. A Probabilistic Framework for Analysing the Compositionality of Conceptual Combinations. Journal of Mathematical Psychology, 67: 26-38, 2015.

[3] E. Dzhafarov, R. Zhang, V. Cervantes, J. Kujala. On Contextuality in Behavioral Data. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 374, 08 2015.

[4] M Pickering, S. Frisson. Processing Ambiguous Verbs: Evidence from Eye Movements, Journal of Experimental Psychology: Learning, Memory, and Cognition, 27:556--73, 2001.

[5] M.K. Tanenhaus, J.M. Leiman, M.S. Seidenberg. Evidence for Multiple Stages in the Processing of Ambiguous Words in Syntactic Contexts, Journal of Verbal Learning and Verbal Behavior, 18(4):427-440, 1979.

We are pleased to announce that the Best Presentation Award sponsored by Entropy for 6th Quantum Information in Spain (ICE6) conference was granted to Dr. Ignacio Gimeno at University of Zaragoza. Congratulations!

• “Broad-Band Spectroscopy of Electronuclear Spin Qudits Based on Vanadyl Porphyrin Molecules” by Dr. Ignacio Gimeno

The possibility of encoding more than a qubit in vanadyl porphyrin molecules hosting a S = 1/2 electronic spin coupled to a I = 7/2 nuclear spin has been explored. A complete study of the spin Hamiltonian and its parameters, as well as the spin dynamics, has been performed via a combination of electron paramagnetic resonance, heat capacity, magnetization and on-chip magnetic spectroscopy experiments performed on single crystals, observing low temperature spin coherence times of micro-seconds and spin relaxation times longer than a second. For sufficiently strong magnetic fields (B > 0.1 T, corresponding to resonance frequencies of 9–10 GHz), these properties make vanadyl porphyrin molecules suitable qubit realizations. The presence of multiple equispaced nuclear spin levels, then, merely provides eight alternatives to define the ‘1’ and ‘0’ basis states. For lower magnetic fields (B < 0.1 T) and lower frequencies (< 2 GHz), spectroscopic signatures of a sizeable electronuclear entanglement arise. This effect generates a larger set of allowed transitions between different electronuclear spin states and removes their degeneracies. Under these conditions, it can be shown that each molecule fulfils the conditions to act as a universal 4-qubit processor or, equivalently, as a d = 16 qudit. These findings widen the catalogue of chemically designed systems that are able to implement non-trivial quantum functionalities, such as quantum simulations and, especially, quantum error correction, at the molecular level.

We are pleased to announce the launch of a project entitled "Editor's Choice Articles" in Entropy. Please click here to find a list of high-quality and interesting papers that have been specifically recommended by our Editorial Board Members. Among which, we have selected 16 papers to display here. The following is the paper list.

We would like to take this opportunity to thank all the research groups of the exceptional papers for their contributions to Entropy. Finally, we would appreciate it if you would circulate this document among your colleagues or through your network.

We are pleased to announce that the Best Contribution Award sponsored by Entropy for 2021 International Workshop Open Quantum Dynamics and Thermodynamics was granted to Dr. Martí Perarnau-Llobet at University of Geneva. Congratulations!

“Optimal Finite-Time Carnot Cycle” by Marti Perarnau-Llobet

We considered the optimization of a finite-time Carnot engine characterized by small dissipations. We bound the power with a simple inequality and showed that the optimal strategy is to perform small cycles around a given working point, which can be thus chosen optimally. Remarkably, this optimal point is independent of the figure of merit combining power and efficiency that is being maximized. Furthermore, for a general class of dynamics, the power output becomes proportional to the heat capacity of the working substance. Since the heat capacity can scale supra-extensively with the number of constituents of the engine, this enables us to design optimal many-body Carnot engines, reaching maximum efficiency at finite power per constituent in the thermodynamic limit.

We are very pleased to announce that Prof. Dr. Geert Verdoolaege has been appointed as Section Editor-in-Chief of the “Multidisciplinary Applications” Section in Entropy (ISSN 1099-4300).

Prof. Dr. Geert Verdoolaege is an Associate Professor in the Department of Applied Physics at Ghent University, where he leads the Research Unit Nuclear Fusion. He teaches the courses Plasma Physics and Continuum Mechanics for physics engineering and physics students, and he is involved in fusion education in Europe through international master and PhD programs. He serves as an expert in the topical groups on Transport and Confinement and on Diagnostics of the International Tokamak Physics Activity (ITPA), as well as in the scientific committees of various plasma physics and mathematics conferences.

His current research activities comprise development and application of advanced data analysis techniques for nuclear fusion experiments, using Bayesian probability theory, machine learning and information geometry. Applications include fusion scaling laws, probabilistic modeling of magnetohydrodynamic instabilities and fusion diagnostics, and predictive maintenance.

We warmly welcome Prof. Dr. Geert Verdoolaege in taking up his role as Section Editor-in-Chief, and we look forward to Entropy achieving many milestones under his leadership.

For further information on the journal Section, please visit:
https://www.mdpi.com/journal/entropy/sections/multidisciplinary_applications

Name: Prof. Dr. Geert Verdoolaege
Email: geert.verdoolaege@ugent.be
Affiliation: Research Unit Nuclear Fusion, Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41, B-9000 Ghent, Belgium
Interests: probability theory; Bayesian inference; machine learning; information geometry; differential geometry; nuclear fusion; plasma physics; continuum mechanics; statistical mechanics
Homepage: nuclearfusion.ugent.be