Entropies and IPR as Markers for a Phase Transition in a Two-Level Model for Atom–Diatomic Molecule Coexistence

A quantum phase transition (QPT) in a simple model that describes the coexistence of atoms and diatomic molecules is studied. The model, which is briefly discussed, presents a second-order ground state phase transition in the thermodynamic (or large particle number) limit, changing from a molecular condensate in one phase to an equilibrium of diatomic molecules–atoms in coexistence in the other one. The usual markers for this phase transition are the ground state energy and the expected value of the number of atoms (alternatively, the number of molecules) in the ground state. In this work, other markers for the QPT, such as the inverse participation ratio (IPR), and particularly, the Rényi entropy, are analyzed and proposed as QPT markers. Both magnitudes present abrupt changes at the critical point of the QPT.

Statistical study of thermoradiative and photovoltaic cells based on a two-level model

We use a two-level energy model to understand the conversion process that takes place in thermoradiative cells and to compare it with the conversion process that happens in photovoltaic cells. In this way, we show that in both kinds of converters the conversion process can be studied as the succession of a change in the populations of the levels that occur at constant chemical potential and a change in the value of the chemical potential of the two levels that happens while keeping their populations constant. As an application of the model, we will discuss why in thermoradiative cells the open-circuit voltage is negative while it is positive in photovoltaic cells. We also show that the expression for the open-circuit voltage is the same in both kinds of cells but that due to the values of the temperatures it is negative in thermoradiative cells and positive in photovoltaic ones.

Tunisian Military and Regime Change

This paper has several research objectives. They are related to the description of the position of the military in the non-democratic regime in Tunisia, as well as to the clarification of its role in the overthrow of the regime, that is, to the identification of the causal factors that determine the military role during uprisings. The purpose of this paper is to show that the support of the military or its neutral position during such uprisings represents necessary condition for success of transition from a non-democratic regime. Applying two-level model of analyses based on the strategic approach to transition, we concluded that the nature of civil-military relations in the previous regime and the nature of protest determine the role of the military in the uprisings. In other words, the character of the previous non-democratic regime and the initiators of transition settle the model and the results of transition, and its consolidation.

Architecture of Intellectual System for Research of Space Weather Parameters

Has been carried out analysis of the subject area and main functions of the intellectual system for research of space weather parameters are identified. The model of static structure of intellectual system is developed as well as its dynamic aspects are modeled. Also is constructed an architecture of intellectual system for research of space weather parameters on the basis of “client-server” two-level model. The scientific novelty of the obtained results stands on developed model of the intellectual system for research of space weather parameters. The practical significance of the intellectual system lies in its capabilities: automated collection and processing of data on the manifestations of solar activity; storing information in the database; data analysis and establishing links between helio- and geo-activity indicators, as well as forecasting geophysical disturbances caused by cosmic factors.

Non-adiabatic dynamics of the entanglement entropy in a symmetry-breaking Haldane insulator

We study the non-adiabatic dynamics of a typical symmetry-protected topological phase-the Haldane insulator phase with broken bond-centered inversion. By continuously breaking the middle chain, we find the gap closes at a critical point in the deep Haldane insulator regime with a change of particle number partition of the left or right system. The adiabatic evolution fails at this critical point and we show how to predict the dynamics of the entanglement entropy near this point using a two-level model. These results show that one can find a critical regime where the entanglement measurement is relatively robust against perturbation that breaks the protecting symmetries in the Haldane insulator. This is in contrast to the common belief that the symmetry-protected topological phases are fragile without the protecting symmetries.

Frame determinism of artistic narrative

The article presents the results of a study undertaken to study the nature and degree of determinism of the plot semantics of artistic narrative by frame structures that serve as the basis of this narrative. The research focused on questions about the properties of frames that predetermine the deployment of narrative (determinant frames); questions about the nature of the connection between plot-forming frames (interframe transitions); questions about the nature, perspective and degree of imperativeness of the constraints imposed by the determinant frames on the deployment of the narrative. It is concluded that the frame as a meaningful unit of the meaning of the text has prospective semantics, from which it follows that any frame that forms the main storyline in the narrative prescribes each functional component of its composition, first of all, the first and second terms, predicates and basic sirconstrants, defined trajectories of further existence in the plot. The assumption is confirmed that the organization of artistic narrative is determined by both superframes-determinants and superstructures that form thematic sequences of macrostructures. The experience of constructing a graphical two-level model of the frame semantics of artistic narrative is presented, the comparison of this model with the representation of the frame in the FrameNet system is carried out. It was also concluded that the systematic and consistent description of the plot-content semantics of the narrative as a kind of literary text requires the same consistent and systematic description of the semantic-syntactic frames that form this semantics. In the systematic description of the frame semantics of narrative, special attention should be paid to predicates of nuclear propositions, since it is their semantic valences that determine the filling of the terminals of semantic-syntactic frames and their description gives explanatory power to the description of the semantic structure of frames. The authors see the prospect of the research in the systematic description of the frame semantics of the narrative with the involvement of the resources of the FrameBank project.

Two-Level Planning of Customized Bus Routes Based on Uncertainty Theory

The optimization problem of customized bus routes is affected by uncertain factors in reality; therefore, this paper introduces uncertainty theory to study the above problem. A two-level planning model that takes the maximum total revenue of the bus company as the upper-level goal and the minimum total travel cost of passengers as the lower-level goal is established, using uncertainty theory to study and solve practical problems with uncertain factors. The genetic algorithm is used to solve the model, and the feasibility of the model is verified through a case study. The research results show that the application of the two-level model of customized bus route planning based on uncertain vehicle operating time established in this paper to customize bus route planning can take into account the travel needs of passengers and high-quality experiences while also bringing benefits to enterprises and achieving a win–win situation. The research in this article provides theoretical support for the optimization of customized bus routes.