Randomness In Interactions Research Articles

Study on proton-induced single event effect of SiC diode and MOSFET

Proton-induced degradation and catastrophic failures in 650 V SiC diode and 900 V SiC MOSFET under different bias voltage and different proton energy are investigated. The experimental results show that when the bias voltage of SiC diode and MOSFET reaches 88% of rated voltage, 20 MeV protons will not cause the single event burnout (SEB) of two SiC devices. When SiC devices are burned out, a wave-shaped pulse current appears, the pulse current peak value gradually decreases, and the total pulse current width is within 5 microseconds. With the increase of bias voltage, the SEB fluence of SiC device is significantly reduced. After SiC diode is burned out, its reverse breakdown voltage is lower than 1 V, and the forward current when device has not been turned on is up to 8 orders of magnitude higher than before irradiation; the reverse breakdown voltage of SiC MOSFET is also lower than 1 V after burning out, only some SiC MOSFETs still maintain transfer characteristics under a voltage bias of 700 V, and the gate-source current has increased by 7–8 orders of magnitude compared to before irradiation. The Monte Carlo simulation results show that the linear energy transfer (LET) of 20 MeV proton in the epitaxial layer is lower than 2 MeV·cm2/mg, which is not enough to generate charge required for SEB. And the randomness of interaction between protons and device materials leads to different SEB fluences for SiC devices under different proton energies.

Spin dynamics and Griffiths singularity in the random quantum Ising magnet PrTiNbO6

In crystalline magnets, interaction randomness is usually thought as a negative factor preventing interesting quantum phenomena to occur. However, intriguing interplay between randomness and quantumness can also leads to unique phenomena in the strongly correlated materials. Among others, the random transverse-field Ising spin chain (RTIC) hosts a renowned quantum Griffiths phase. Although the RTIC model has been regarded as a toy model for long, here we materialize this model with the compound PrTiNbO6, which has a disordered ground state with pronounced quantum fluctuations and continuous spin excitations. The observed anomalous spin dynamics of PrTiNbO6 can be accounted by the RTIC model with a consistent set of parameters determined from fitting the thermodynamic data, and it is ascribed to the quantum Griffiths rare regions in the system. Our results provide a concrete example of quantum Griffiths magnet, and offer an ideal experimental platform for investigating the dynamical properties of random many-body system.

How Does the Heterogeneity of Members Affect the Evolution of Group Opinions?

Understanding the impact of heterogeneity on the evolution of group opinions can enlighten us on how to effectively organize, redesign, and improve decision-making efficiency. This article explores mainly the effects of heterogeneity on the evolution of group opinions. It is found that the heterogeneity of individuals’ openness has an important influence on the ability to aggregate group opinions. According to the average amount of clusters and Herfindahl–Hirschman Index (HHI) under different network structures, heterogeneity often improves the ability. In addition, for the small-world network and random network, there is little difference in the aggregation ability from both the average amount of clusters and the Herfindahl–Hirschman Index. While for the regular network, the ability is obviously weaker than that of the other two. This result also shows that the randomness of interaction between members will enhance the cohesion of a group.

Современный этап истории межрегионального российско-китайского сотрудничества в условиях регионализации

The article is devoted to the analysis of modern processes of interregional cooperation in the Far East in the context of regionalization. The analysis was based on Russian-Chinese interregional interaction. Based on the theory of new regionalism, the contemporary role of regions in the 21st century was determined. The Russian foreign policy strategy “Turn to the East”, outlined in 2014, has established new prospects for interaction between Russian and Chinese regions in the Far East. An analysis of the work of Russian and Chinese scientists, plans, programs for maintaining Russian-Chinese cooperation, annual reports of departments, committees for international cooperation under the administrations of the Russian regions allows us to highlight the general trade, economic, economic, socio-cultural and scientific-technical problems of interregional cooperation. The main ones include: spontaneity and randomness of interaction between the regions of Russia and China in the last decade of the twentieth century; mutual trust in Russian-Chinese interregional relations; imbalances in the development of transport and logistics infrastructure of the Northeast of China and the Far East of Russia; problems of sectoral complementarity of the border regions of Russia and China.

Zealots tame oscillations in the spatial rock-paper-scissors game.

The rock-paper-scissors game is a paradigmatic model for biodiversity, with applications ranging from microbial populations to human societies. Research has shown, however, that mobility jeopardizes biodiversity by promoting the formation of spiral waves, especially if there is no conservation law in place for the total number of competing players. First, we show that even if such a conservation law applies, mobility still jeopardizes biodiversity in the spatial rock-paper-scissors game if only a small fraction of links of the square lattice is randomly rewired. Secondly, we show that zealots are very effective in taming the amplitude of oscillations that emerge due to mobility and/or interaction randomness, and this regardless of whether the later is quenched or annealed. While even a tiny fraction of zealots brings significant benefits, at 5% occupancy zealots practically destroy all oscillations regardless of the intensity of mobility, and regardless of the type and strength of randomness in the interaction structure. Interestingly, by annealed randomness the impact of zealots is qualitatively the same as by mobility, which highlights that fast diffusion does not necessarily destroy the coexistence of species, and that zealotry thus helps to recover the stable mean-field solution. Our results strengthen the important role of zealots in models of cyclic dominance, and they reveal fascinating evolutionary outcomes in structured populations that are a unique consequence of such uncompromising behavior.

Vortices determine the dynamics of biodiversity in cyclical interactions with protection spillovers

If rock beats scissors and scissors beat paper, one might assume that rock beats paper too. But this is not the case for intransitive relationships that make up the famous rock-paper-scissors game. However, the sole presence of paper might prevent rock from beating scissors, simply because paper beats rock. This is the blueprint for the rock-paper-scissors game with protection spillovers, which has recently been introduced as a new paradigm for biodiversity in well-mixed microbial populations. Here we study the game in structured populations, demonstrating that protection spillovers give rise to spatial patterns that are impossible to observe in the classical rock-paper-scissors game. We show that the spatiotemporal dynamics of the system is determined by the density of stable vortices, which may ultimately transform to frozen states, to propagating waves, or to target waves with reversed propagation direction, depending further on the degree and type of randomness in the interactions among the species. If vortices are rare, the fixation to waves and complex oscillatory solutions is likelier. Moreover, annealed randomness in interactions favors the emergence of target waves, while quenched randomness favors collective synchronization. Our results demonstrate that protection spillovers may fundamentally change the dynamics of cyclic dominance in structured populations, and they outline the possibility of programming pattern formation in microbial populations.

Importance of randomness in biological networks: A random matrix analysis

Random matrix theory, initially proposed to understand the complex interactions in nuclear spectra, has demonstrated its success in diverse domains of science ranging from quantum chaos to galaxies. We demonstrate the applicability of random matrix theory for networks by providing a new dimension to complex systems research. We show that in spite of huge differences these interaction networks, representing real-world systems, posses from random matrix models, the spectral properties of the underlying matrices of these networks follow random matrix theory bringing them into the same universality class. We further demonstrate the importance of randomness in interactions for deducing crucial properties of the underlying system. This paper provides an overview of the importance of random matrix framework in complex systems research with biological systems as examples.

Quantifying randomness in protein–protein interaction networks of different species: A random matrix approach

We analyze protein–protein interaction networks for six different species under the framework of random matrix theory. Nearest neighbor spacing distribution of the eigenvalues of adjacency matrices of the largest connected part of these networks emulate universal Gaussian orthogonal statistics of random matrix theory. We demonstrate that spectral rigidity, which quantifies long range correlations in eigenvalues, for all protein–protein interaction networks follow random matrix prediction up to certain ranges indicating randomness in interactions. After this range, deviation from the universality evinces underlying structural features in network.

Similarity and Probability Distribution Functions in Many-Body Stochastic Processes with Multiplicative Interactions

Analytical and numerical studies on many-body stochastic processes with multiplicative interactions are reviewed. The method of moment relations is used to investigate effects of asymmetry and randomness in interactions. Probability distribution functions of the processes generally have similarity solutions with power-law tails. Growth rates of the system and power-law exponents of the tails are determined via transcendental equations. Good agreement is achieved between analytical calculations and Monte Carlo simulations.

Magnetic Properties of Tetragonal Ce1-xLuxB2C2(0 ≤x≤0.31) Compounds

Specific heat, dc - and ac -magnetic susceptibility and magnetization measurements were performed on rare earth intermetallic compounds Ce 1- x Lu x B 2 C 2 (0 ≤ x ≤0.31) in order to elucidate the magnetic interaction in CeB 2 C 2 . In the process of the substitution of Ce by Lu in CeB 2 C 2 , the characteristics of magnetic transition change from a first-order transition to a second-order one. Furthermore, the spin-glass phase appears at Lu concentration x =0.31. We suppose that the ferromagnetic (FM) and antiferromagnetic (AFM) interactions compete and nearly cancel out each other in CeB 2 C 2 , and hence that a biquadratic interaction might cause the first-order magnetic transition at T N . The Lu substitution breaks the competition between AFM and FM interactions and brings forth randomness in interactions acting on each Ce moment. The typical spin-glass behavior of x =0.31 originates in this random distribution of magnetic interactions.