Article
Physics, Multidisciplinary
Jinn-Wen Wu, Hong-Yuan Xu, Yu-Pin Luo, Ming-Chang Huang
Summary: This paper establishes and analyzes the conditions on the stationary and state-varying transition probabilities in the corresponding discrete-time Markov chains, which lead to the occurrence of uniform collective behaviors. It introduces a new measure called the minimal time-interval of coherent transmission of informations to qualitatively characterize the convergence speed towards a uniform collective behavior. The numerical calculations on the proposed models show that this measure is consistent with the geometric distance of the corresponding network of dynamical system.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Operations Research & Management Science
Dongdong Liu, Wen Li, Yannan Chen
Summary: This paper introduces a system of cyclic stationary probability distribution equations for a second order Markov chain process, assuming all states are independent, which improves upon existing equations. The new model has two applications and properties of the solutions for the proposed stationary equation are investigated.
PACIFIC JOURNAL OF OPTIMIZATION
(2021)
Article
Environmental Sciences
Saad Sh. Sammen, Ozgur Kisi, Mohammad Ehteram, Ahmed El-Shafie, Nadhir Al-Ansari, Mohammad Ali Ghorbani, Shakeel Ahmad Bhat, Ali Najah Ahmed, Shamsuddin Shahid
Summary: Rainfall is crucial for water resources management. This study used six hybrid soft computing models to forecast monthly rainfall at two stations in Malaysia and found that the MLP-HGSO model performed the best in predicting rainfall.
ENVIRONMENTAL SCIENCES EUROPE
(2023)
Article
Mathematics, Applied
Zhenfeng Shi, Daqing Jiang, Xinhong Zhang, Ahmed Alsaedi
Summary: This paper proposes a stochastic SEIRS rabies epidemic model with two patches to investigate the spatial spread of rabies under the influence of environmental noise. By adopting a new technique to construct stochastic Lyapunov functions, sufficient conditions for the existence of an ergodic stationary distribution are obtained. Moreover, the exact expression of probability density function around a quasi-equilibrium point is derived when the movement of dogs is forbidden.
APPLIED MATHEMATICS AND COMPUTATION
(2022)
Article
Mathematics, Applied
Aiping Deng, Yuting Hu
Summary: This paper examines the stationary probability vectors of a second order Markov chain and investigates the geometrical structure of the set of these vectors with finite ones known stationary. Using elementary methods, it is deduced that if three vectors on a line segment in the standard simplex are stationary probability vectors of a second order Markov chain, then the set of stationary probability vectors of the chain contains all vectors on the segment. Two generalizations of this result are provided for any plane sections of the standard simplex based on properties of quadratic stochastic operators and affine subspaces. These generalizations claim that the stationarity of all vectors of any given plane section of the simplex is equivalent to the stationarity of finite vectors in some appropriate positions of the section. Furthermore, the obtained results are applied to discuss the minimum number of such known stationary vectors as interior points for faces.
RESULTS IN MATHEMATICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Junyan Ge, Wenjie Zuo, Daqing Jiang
Summary: This paper presents a stochastic HBV infection model and investigates its dynamic behaviors. It establishes the existence and ergodicity of the model's stationary distribution, determines the critical value corresponding to the basic reproduction number, and provides conditions for disease persistence or extinction. The specific expression of the probability density function around the endemic quasi-equilibrium is also derived, and numerical simulations confirm theoretical results and match HBV epidemic data in China.
MATHEMATICS AND COMPUTERS IN SIMULATION
(2022)
Article
Mathematics, Applied
Qun Liu
Summary: In this paper, a stochastic SISP respiratory disease system with Ornstein-Uhlenbeck process is established and analyzed to describe the transmission dynamics of respiratory disease in the population. The existence and uniqueness of a global solution for any initial value are verified. Sufficient criteria for the existence of a stationary distribution of positive solutions are obtained using a stochastic Lyapunov function method.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Review
Automation & Control Systems
Dan Li, Fengying Wei, Xuerong Mao
Summary: In this paper, we investigate the long-term properties of a stochastic SVIR epidemic model with saturation incidence rates and logistic growth. We derive the fitness of a unique global positive solution, establish appropriate Lyapunov functions, and determine conditions for the existence of stationary distribution and persistence in the mean. We also identify conditions for exponential extinction of infected individuals. Furthermore, we use the Fokker-Planck equation and stochastic analysis to derive the probability density function around the quasi-endemic equilibrium point. The main theoretical results are verified through examples and illustrative simulations.
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS
(2022)
Article
Statistics & Probability
Jan G. De Gooijer
Summary: This paper addresses the problem of finding exact and explicit expressions for the stationary marginal distribution of threshold-type time series processes, and their associated moments, autocovariance and autocorrelation coefficients. Theoretical results for two- and three-regime threshold-type models are derived and various examples provide a deeper understanding of certain features of the stationary process structure. Exact results are compared with approximate results obtained through an existing numerical method for the stationary density, central moments, and autocorrelations of threshold-type processes.
Article
Mathematics
Xiaoxiao Wang, Chaoqian Li, Yaotang Li
Summary: This paper provides several new uniqueness conditions for the stationary probability matrix of transition probability tensors arising from higher-order multivariate Markov chains. Numerical examples demonstrate that the new results are simpler and easier to verify compared to those provided by Li et al. (Comput Math Appl 78:1008-1025, 2019). Additionally, a new convergence theorem for the power method to calculate the stationary probability matrix is presented, along with several perturbation bounds of the matrix.
BULLETIN OF THE IRANIAN MATHEMATICAL SOCIETY
(2022)
Article
Economics
Minsoo Jeong
Summary: This paper presents a novel approach to model financial time series that captures both persistency and long term stationarity. The provided statistical theory and empirical evidence support the existence and characteristic behavior of such series in real financial data.
ECONOMIC MODELLING
(2022)
Article
Mathematics, Applied
Dongchen Shangguan, Zhijun Liu, Lianwen Wang, Ronghua Tan
Summary: Two types of stochastic epidemic models were studied, incorporating infectivity in the latent period and household quarantine measures. The results showed that stochastic perturbations and household quarantine measures have a significant impact on both periodicity and stationary distribution, as supported by numerical simulations.
JOURNAL OF APPLIED MATHEMATICS AND COMPUTING
(2022)
Article
Chemistry, Analytical
Namuk Park, Songkuk Kim
Summary: Efficient and accurate estimation of probability distribution for non-stationary data streams is a crucial problem in sensor systems, requiring agile adaptation for concept drift. The proposed FlexSketch algorithm utilizes an ensemble of histograms to generate probability distribution, swiftly detecting and responding to concept drift, achieving high update speed and accuracy with limited memory. Experimental results show improved speed and accuracy compared to existing methods for both stationary and non-stationary data streams.
Article
Social Sciences, Mathematical Methods
Yves Tille, Bardia Panahbehagh
Summary: In this article, the implementation of maximum entropy (ME) design using a Markov chain is studied. A new method for calculating the weights associated with conditional Poisson sampling is presented. A simple method of random exchanges of units is studied, which allows switching from one sample to another. By repeating the exchange process, a sample that respects the design can be selected, and its convergence rate has been investigated theoretically and by simulation, showing promising results.
JOURNAL OF SURVEY STATISTICS AND METHODOLOGY
(2023)
Article
Computer Science, Interdisciplinary Applications
Wei Cao, Annan Zhou, Shui-Long Shen
Summary: Geological uncertainty widely impacts the deformation and stability of geotechnical structures, with the coupled Markov chain (CMC) model being a common method to simulate strata variability. In this study, an analytical method for estimating the horizontal transition probability matrix (HTPM) is proposed to enhance the CMC model in simulating geological uncertainty based on given borehole data, showing good agreement with real values and insensitivity to borehole schemes.
COMPUTERS AND GEOTECHNICS
(2021)
Article
Chemistry, Physical
Mariusz P. Mitoraj, Filip Sagan, Dariusz W. Szczepanik, Jurgens H. de Lange, Aleksandra L. Ptaszek, Daniel M. E. van Niekerk, Ignacy Cukrowski
Article
Chemistry, Multidisciplinary
Dinara S. Shapenova, Alexey A. Shiryaev, Michael Bolte, Mercedes Kukulka, Dariusz W. Szczepanik, James Hooper, Maria G. Babashkina, Ghodrat Mahmoudi, Mariusz P. Mitoraj, Damir A. Safin
CHEMISTRY-A EUROPEAN JOURNAL
(2020)
Article
Chemistry, Multidisciplinary
Dandan Chen, Dariusz W. Szczepanik, Jun Zhu, Miquel Sola
CHEMISTRY-A EUROPEAN JOURNAL
(2020)
Article
Chemistry, Multidisciplinary
Dandan Chen, Dariusz W. Szczepanik, Jun Zhu, Alvaro Munoz-Castro, Miquel Sola
Summary: The study explores the C-13 NMR spectroscopy and aromatic behavior of a unique non-IPR hydrofullerene, C-2v C66H4, revealing its distinct features compared to C-60 and its increased aromaticity under specific orientations of the external field.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Biochemistry & Molecular Biology
Ghodrat Mahmoudi, Maria G. Babashkina, Waldemar Maniukiewicz, Farhad Akbari Afkhami, Bharath Babu Nunna, Fedor I. Zubkov, Aleksandra L. Ptaszek, Dariusz W. Szczepanik, Mariusz P. Mitoraj, Damir A. Safin
Summary: This work discusses the solvent-induced complexation properties of a N2S2 tetradentate bis-thiosemicarbazone ligand towards nickel(II), resulting in the formation of two different mononuclear homoleptic complexes. The crystal structures of these complexes reveal unique seesaw coordination geometries and a variety of intermolecular interactions, such as N-H···S and C-H···Ni preagostic interactions. Additionally, the electron density analysis suggests a weak σ-metalloaromatic character around the nickel(II) atom.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Chemistry, Multidisciplinary
Dariusz W. Szczepanik
Summary: In this study, the first thorium-thorium bond in a crystalline cluster prepared under normal experimental conditions was reported. The presence of two delocalized paired electrons and a sigma-aromatic three-center two-electron bond in the isolated actinide cluster was confirmed. However, further investigation revealed that the previously observed inelastic scattering bands attributed to thorium-thorium vibrations actually represented the combination of Th-Cl stretching and Th-Cl-Th bending modes, establishing the existence of an unprecedented multicenter charge-shift bonding structure.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Ouissam El Bakouri, Dariusz W. Szczepanik, Kjell Jorner, Rabia Ayub, Patrick Bultinck, Miquel Sola, Henrik Ottosson
Summary: Several fully pi-conjugated macrocycles with puckered or cage-type structures were found to exhibit aromatic character. However, they should be described as 2D-aromatic-in-3D structures rather than truly 3D-aromatic compounds. Their aromaticity comes from the fulfillment of specific rules and is related to naphthalene.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Multidisciplinary Sciences
Hong-Lei Xu, Nikolay Tkachenko, Dariusz W. Szczepanik, Ivan A. Popov, Alvaro Munoz-Castro, Alexander Boldyrev, Zhong-Ming Sun
Summary: Investigating the structural transformations from atomic clusters to bulk materials is challenging. In this study, the authors synthesized and characterized a germanium cluster Ge-24(4-), and found that electron delocalization plays a vital role in its formation and stabilization.
NATURE COMMUNICATIONS
(2022)
Correction
Biochemistry & Molecular Biology
Ghodrat Mahmoudi, Maria G. Babashkina, Waldemar Maniukiewicz, Farhad Akbari Afkhami, Bharath Babu Nunna, Fedor I. Zubkov, Aleksandra L. Ptaszek, Dariusz W. Szczepanik, Mariusz P. Mitoraj, Damir A. Safin
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Review
Chemistry, Organic
Weixuan Zeng, Dariusz W. Szczepanik, Hugo Bronstein
Summary: This review focuses on indolonaphthyridine (IND) derivative chromophores and their ability to undergo singlet fission with superior ambient stability. The research explores the excited-state Huckel-aromatic and diradical characters and provides a feasible design strategy for other scaffolds to undergo singlet fission and excited-state aromaticity.
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Henric Steffenfauseweh, Dennis Rottschaefer, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Dariusz W. Szczepanik, Rajendra S. Ghadwal
Summary: A bordeaux-red solid compound based on an anionic dicarbene (ADC) with a central six-membered C4Sb2 ring is reported. The compound undergoes 2 e-oxidation to form a brick-red solid with unpaired electrons and lone pairs. The diradical character of the compound is calculated to be 36-39% according to different methods.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Kazuki Nakanishi, Leonardo I. Lugo-Fuentes, Jun Manabe, Ronghao Guo, Soichi Kikkawa, Seiji Yamazoe, Kenji Komaguchi, Shoko Kume, Dariusz W. Szczepanik, Miquel Sola, J. Oscar C. Jimenez-Halla, Sadafumi Nishihara, Kazuyuki Kubo, Masaaki Nakamoto, Yohsuke Yamamoto, Tsutomu Mizuta, Rong Shang
Summary: This work reports the oxidation behavior of an all-carbon-ligated iridium complex and successfully synthesizes a high-valent iridium complex bearing a CCCC-tetradentate ligand. These results close a synthetic gap for carbon-ligated iridium complexes and demonstrate the electronic tuning potential of organic pi ligands for unusual electronic properties.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Ghodrat Mahmoudi, Vali Alizadeh, Alfonso Castineiras, Farhad Afkhami, Mariusz P. Mitoraj, Dariusz W. Szczepanik, Irina A. Konyaeva, Koen Robeyns, Damir A. Safin
Summary: This study reports on the design, structure, spectroscopic and computational characterization of two new quasi-aromatic Mobius chelate coordination compounds. These compounds were synthesized from Cd(NO3)(2)center dot 4H(2)O and a bulky helical organic ligand derived from benzildihydrazone and 2-pyridinecarboxaldehyde (L). The crystal structures and optical properties of these compounds were investigated.
Article
Chemistry, Multidisciplinary
Weixuan Zeng, Ouissam El Bakouri, Dariusz W. Szczepanik, Hugo Bronstein, Henrik Ottosson
Summary: This study presents a revised theoretical analysis to design new organic chromophores based on Huckel aromaticity, showing the potential of manipulating excited state energy levels by adjusting substituents. Improved understanding of aromatic characters allows for a feasible design strategy to vary excited state energy levels by tuning the number and nature of Huckel-aromatic units. The complications and pitfalls of excited state aromaticity and antiaromaticity concepts are highlighted, emphasizing the need to link quantitative results with qualitative theoretical analysis.
Article
Chemistry, Multidisciplinary
Dandan Chen, Dariusz W. Szczepanik, Jun Zhu, Miquel Sola
CHEMICAL COMMUNICATIONS
(2020)
