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© 2024 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0, Bipartite secret sharing schemes have a bipartite access structure in which the set of participants is divided into two parts and all participants in the same part play an equivalent role. Such a bipartite scheme can be described by a staircase: the collection of its minimal points. The complexity of a scheme is the maximal share size relative to the secret size; and the ¿-complexity of an access structure is the best lower bound provided by the entropy method. An access structure is ¿-ideal if it has ¿-complexity 1. Motivated by the abundance of open problems in this area, the main results can be summarized as follows. First, a new characterization of ¿-ideal multipartite access structures is given which offers a straightforward and simple approach to describe ideal bipartite and tripartite access structures. Second, the ¿-complexity is determined for a range of bipartite access structures, including those determined by two points, staircases with equal widths and heights, and staircases with all heights 1. Third, matching linear schemes are presented for some non-ideal cases, including staircases where all heights are 1 and all widths are equal. Finally, finding the Shannon complexity of a bipartite access structure can be considered as a discrete submodular optimization problem. An interesting and intriguing continuous version is defined which might give further insight to the large-scale behavior of these optimization problems., The work of the first author was partially supported by the ERC Advanced Grant ERMiD. The work of third author was supported by the Spanish Government (MICINN) under Project PID2019-109379RB-I00., Peer Reviewed, Postprint (author's final draft)

The development of nautical education is not only related to the cultivation of talents, but also to the future of the country, so it is important to conduct research on the evaluation of the quality of nautical education. In order to improve the applicability of the evaluation results, this paper investigates the views of the students and teachers of Wuhan University of Technology’s nautical courses on the factors affecting the quality of nautical education by means of questionnaires. Based on the results of the questionnaire, the entropy weighting method was used to rank the satisfaction of each factor reflecting the quality of education, and the correlation between the ranking of students and teachers was tested, and the results showed a high linear correlation, which indicates that the satisfaction level of the two categories of people with the factors reflecting the quality of nautical education is generally the same, and both categories of people think that the completeness of current teaching facilities and the adequacy of practical training are significantly insufficient, which is the current stage This is a problem that needs to be improved. The results of this study have important implications for improving the quality of maritime education., QC 20230725

We study a two-species cross-diffusion model that is inspired by a system of convectiondiffusion equations derived from an agent-based model on a two-dimensional discrete lattice. The latter model has been proposed to simulate gang territorial development through the use of graffiti markings. We find two energy functionals for the system that allow us to prove a weak-stability result and identify equilibrium solutions. We show that under the natural definition of weak solutions, obtained from the weak-stability result, the system does not allow segregated solutions. Moreover, we present a result on the long-term behavior of solutions in the case when the masses of the densities are smaller than a critical value. This result is complemented with numerical experiments., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Mathematical Physics

The focus of the present study is on the financial markets of Iran. In fact, the purpose of the present study is to examine the critical state of the Iranian stock market and compare it with one of the famous American markets called Dow Jones. The purpose of the financial crisis is to examine the effect of the interaction of companies within a market. According to modern financial theory, crisis is a phenomenon of market orientation and finding a negative preferred direction among companies. The stock market data of 180 companies of this market that were active during the period of 2008 to 2019 were used to investigate the financial crisis of the Iranian Stock Exchange. The results show that the average transfer entropy for 180 firms in the Iranian stock market is more random. That is to say, the observed declines do not correspond to the time periods of the crisis in the stock market. Although transfer entropy seems to be a good indicator for determining the period of crisis in the US Dow Jones market, it cannot be an indicator for determining the financial crisis for the Iranian stock market., El enfoque del presente estudio está en los mercados financieros de Irán. De hecho, el propósito del presente estudio es examinar el estado crítico del mercado bursátil iraní y compararlo con uno de los famosos mercados estadounidenses llamado Dow Jones. El propósito de la crisis financiera es examinar el efecto de la interacción de las empresas dentro de un mercado. Según la teoría financiera moderna, la crisis es un fenómeno de orientación al mercado y de encontrar una dirección preferida negativa entre las empresas. Los datos del mercado de valores de 180 empresas de este mercado que estuvieron activas durante el período de 2008 a 2019 se utilizaron para investigar la crisis financiera de la Bolsa de Valores de Irán. Los resultados muestran que la entropía de transferencia promedio para 180 empresas en el mercado bursátil iraní es más aleatoria. Es decir, los descensos observados no corresponden a los períodos de tiempo de la crisis en el mercado de valores. Aunque la entropía de transferencia parece ser un buen indicador para determinar el período de crisis en el mercado estadounidense Dow Jones, no puede ser un indicador para determinar la crisis financiera del mercado bursátil iraní.

We study a two-species cross-diffusion model that is inspired by a system of convectiondiffusion equations derived from an agent-based model on a two-dimensional discrete lattice. The latter model has been proposed to simulate gang territorial development through the use of graffiti markings. We find two energy functionals for the system that allow us to prove a weak-stability result and identify equilibrium solutions. We show that under the natural definition of weak solutions, obtained from the weak-stability result, the system does not allow segregated solutions. Moreover, we present a result on the long-term behavior of solutions in the case when the masses of the densities are smaller than a critical value. This result is complemented with numerical experiments., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Mathematical Physics

We consider a rather general class of non-local in time Fokker–Planck equations and show by means of the entropy method that as t→∞, the solution converges in L1 to the unique steady state. Important special cases are the time-fractional and ultraslow diffusion case. We also prove estimates for the rate of decay. In contrast to the classical (local) case, where the usual time derivative appears in the Fokker–Planck equation, the obtained decay rate depends on the entropy, which is related to the integrability of the initial datum. It seems that higher integrability of the initial datum leads to better decay rates and that the optimal decay rate is reached, as we show, when the initial datum belongs to a certain weighted L2 space. We also show how our estimates can be adapted to the discrete-time case thereby improving known decay rates from the literature.

The sustainable development of mining occupational health and safety management system is inseparable from its internal and external environment. Through IFE and EFE matrix models, the key internal and external factors affecting the sustainable development of some mining in the Southwest of the Hubei Province are analyzed. Then entropy method is adopted to determine the weight of each key factor. According to the weighted total score ranking, the most important internal and external key factors affecting China's sustainable development include the following: not enough detailed degree of hazard identification, not enough safety awareness, lack of contingency plans to assess the timely exercise, not enough deep mining of internal audit, impact of relevant laws and regulations on enterprises, impact of the interested parties on the changing requirements of the enterprise, risk management brought by interested parties, risk management of product life cycle, and changes in the market environment for enterprises to put forward new requirements. In this paper, combined with OHSAS18001 operation condition of the mining in the Southwest of Hubei Province, seven suggestions for improvement are put forward which provide valuable reference for the sustainable development of mining OHSAS18001., Validerad;2018;Nivå 1;2018-04-18 (andbra)

The sustainable development of mining occupational health and safety management system is inseparable from its internal and external environment. Through IFE and EFE matrix models, the key internal and external factors affecting the sustainable development of some mining in the Southwest of the Hubei Province are analyzed. Then entropy method is adopted to determine the weight of each key factor. According to the weighted total score ranking, the most important internal and external key factors affecting China's sustainable development include the following: not enough detailed degree of hazard identification, not enough safety awareness, lack of contingency plans to assess the timely exercise, not enough deep mining of internal audit, impact of relevant laws and regulations on enterprises, impact of the interested parties on the changing requirements of the enterprise, risk management brought by interested parties, risk management of product life cycle, and changes in the market environment for enterprises to put forward new requirements. In this paper, combined with OHSAS18001 operation condition of the mining in the Southwest of Hubei Province, seven suggestions for improvement are put forward which provide valuable reference for the sustainable development of mining OHSAS18001., Validerad;2018;Nivå 1;2018-04-18 (andbra)

We consider a Shockley–Read–Hall recombination–drift–diffusion model coupled to Poisson’s equation and subject to boundary conditions, which imply conservation of the total charge. As main result, we derive an explicit functional inequality between relative entropy and entropy production rate, which implies exponential convergence to equilibrium with explicit constant and rate. We report that the key entropy–entropy production inequality ought rather not to be formulated on the states space of the parabolic–elliptic system, but on the reduced states space of the associated nonlocal drift–diffusion problem, where the Poisson equation is replaced by the corresponding Green function.

We consider a Shockley–Read–Hall recombination–drift–diffusion model coupled to Poisson’s equation and subject to boundary conditions, which imply conservation of the total charge. As main result, we derive an explicit functional inequality between relative entropy and entropy production rate, which implies exponential convergence to equilibrium with explicit constant and rate. We report that the key entropy–entropy production inequality ought rather not to be formulated on the states space of the parabolic–elliptic system, but on the reduced states space of the associated nonlocal drift–diffusion problem, where the Poisson equation is replaced by the corresponding Green function.

The fast reaction limit of a volume–surface reaction–diffusion system is rigorously investigated. The system is motivated by proteins localisation in stem cell division. By using Ball’s energy equation method, we show that as the reaction rate constant goes to infinity, the solution of the original system converges to the solution of a heat equation with dynamical boundary condition. As a consequence, the dynamical boundary condition can be interpreted as a fast reaction limit of a volume–surface reaction–diffusion system.

The fast reaction limit of a volume–surface reaction–diffusion system is rigorously investigated. The system is motivated by proteins localisation in stem cell division. By using Ball’s energy equation method, we show that as the reaction rate constant goes to infinity, the solution of the original system converges to the solution of a heat equation with dynamical boundary condition. As a consequence, the dynamical boundary condition can be interpreted as a fast reaction limit of a volume–surface reaction–diffusion system.

We contribute to the program of proving lower bounds on the size of branching programs solving the Tree Evaluation Problem introduced in (Stephen A. Cook, Pierre McKenzie, Dustin Wehr, Mark Braverman, and Rahul Santhanam, 2012). Proving an exponential lower bound for the size of the non-deterministic thrifty branching programs would separate NL from P under the thrifty hypothesis. In this context, we consider a restriction of non-deterministic thrifty branching programs called bitwise-independence. We show that any bitwise-independent non-deterministic thrifty branching program solving BT_2(h,k) must have at least 1/2 k^{h/2} states. Prior to this work, lower bounds were known for general branching programs only for fixed heights h=2,3,4 (Stephen A. Cook, Pierre McKenzie, Dustin Wehr, Mark Braverman, and Rahul Santhanam, 2012). Our lower bounds are also tight (up to a factor of k), since the known (Stephen A. Cook, Pierre McKenzie, Dustin Wehr, Mark Braverman, and Rahul Santhanam, 2012) non-deterministic thrifty branching programs for this problem of size O(k^{h/2+1}) are bitwise-independent. We prove our results by associating a fractional pebbling strategy with any bitwise-independent non-deterministic thrifty branching program solving the Tree Evaluation Problem. Such a connection was not known previously even for fixed heights. Our main technique is the entropy method introduced by Jukna and Zak (S. Jukna and S. Žák, 2003) originally in the context of proving lower bounds for read-once branching programs. We also show that the previous lower bounds known (Stephen A. Cook, Pierre McKenzie, Dustin Wehr, Mark Braverman, and Rahul Santhanam, 2012) for deterministic branching programs for Tree Evaluation Problem can be obtained using this approach. Using this method, we also show tight lower bounds for any k-way deterministic branching program solving Tree Evaluation Problem when the instances are restricted to have the same group operation in all internal nodes.