The Variability of the Narrow-line Seyfert 1 Galaxies from the Pan-STARRS's View

By means of the data sets from the Pan-STARRS1 survey, we have systematically examined the relationship between the variability characteristics and the physical parameters of the largest NLS1 galaxy sample up to now.The results are summarized as follows:(1). We find significant anti-correlations between variability amplitude and absolute magnitude in g, r, i, z and y bands, which are consistent with the results in previous works.(2) The correlations between the variability amplitude in optical band and many physical parameters(e.g., λL(5100 A),black hole mass, Eddington ratio, R;and R;) are investigated. The results show the variability amplitude is significantly anti-correlated with L(5100 A), MBH, Eddington ratio and R_(4570), but positively correlated with R;.The relation could be explained by the simple standard accretion disk model.(3) We further investigate the relationship between optical variability and radio luminosity/radio-loudness. The results present weak positive correlation in g and r bands, but insignificant correlation in i, z and y bands. The large error of the approximate fraction of the host galaxy in i, z and y bands may lead to insignificant correlations.

A Game Theoretic Approach for a Minimal Secure Dominating Set

The secure dominating set(SDS),a variant of the dominating set,is an important combinatorial structure used in wireless networks.In this paper,we apply algorithmic game theory to study the minimum secure dominating set(Min SDS) problem in a multi-agent system.We design a game framework for SDS and show that every Nash equilibrium(NE) is a minimal SDS,which is also a Pareto-optimal solution.We prove that the proposed game is an exact potential game,and thus NE exists,and design a polynomial-time distributed local algorithm which converges to an NE in O(n) rounds of interactions.Extensive experiments are done to test the performance of our algorithm,and some interesting phenomena are witnessed.

An Incentive Mechanism for Federated Learning:A Continuous Zero-Determinant Strategy Approach

As a representative emerging machine learning technique, federated learning(FL) has gained considerable popularity for its special feature of “making data available but not visible”. However, potential problems remain, including privacy breaches, imbalances in payment, and inequitable distribution.These shortcomings let devices reluctantly contribute relevant data to, or even refuse to participate in FL. Therefore, in the application of FL, an important but also challenging issue is to motivate as many participants as possible to provide high-quality data to FL. In this paper, we propose an incentive mechanism for FL based on the continuous zero-determinant(CZD) strategies from the perspective of game theory. We first model the interaction between the server and the devices during the FL process as a continuous iterative game. We then apply the CZD strategies for two players and then multiple players to optimize the social welfare of FL, for which we prove that the server can keep social welfare at a high and stable level. Subsequently, we design an incentive mechanism based on the CZD strategies to attract devices to contribute all of their high-accuracy data to FL.Finally, we perform simulations to demonstrate that our proposed CZD-based incentive mechanism can indeed generate high and stable social welfare in FL.

Investigation on the 773K isothermal section of Ho-Ni-Si ternary phase diagram by X-ray powder diffraction and magnetic property of Ho3NiSi2 alloy

The isothermal section of the Ho-Ni-Si system at 773 K was constructed by X-ray powder diffraction(XRD)in this work.The system contains sixteen known type structure compounds TiNiSi-type HoNiSi,BaAl4-type HoNi2Si2,CeNiSi2-type HoNiSi2,U1Co3Si5-type Ho2Ni3Si5,SmNiGe3-type HoNiSi3,Ce3 Ni6Si2-type Ho3Ni6Si2,ThMn12-type HoNi10Si2,YPd2Si-type HoNi2Si,YNi5Si3-type HoNi5Si3,YNi4Si-type HoNi4Si,Gd3NiSi2-type Ho3NiSi2,YNi6Si6-type HoNi6Si6.AlB2-type Ho2NiSi3,AlB2-type Ho3Ni2Si4,AlB2-type Ho4NiSi7,Gd3Ru4Al12-type Ho8Ni31Si11,and one unknown type structure compound Ho5Ni2Si3.At the same time,one unknown structure new phase Ho37Ni3Si60 was observed.In ternary compounds,Ho2NiSi3 and Ho4NiSi7 have the solid solution phenomena;the solid solution ranges are about Ho33.3Ni18.7-9.7Si-48.0-57.0 and Ho33.Ni-8.3-2.6Si-58.3-64.1,respectively.At the same time,quasi-binary solid solutions were detected at 773 K for Ho2Ni17,HoNi5,Ho2Ni7,HoNi3,HoNi2,HoNi,HoSi.Other binary compounds of the Ho-Ni-Si system do not show any visible solubility.The magnetic property studies show that Ho3NiSi2 compound has two successive magnetic phase transitions in a low field:a spinreorientation transition at TSR=10 K and a second order ferromagnetic(FM)-paramagnetic(PM)transition at Tc=37 K.

Experimental isothermal section phase diagram of Ho-Fe-In at 773 K and magnetic properties of Ho_(12)Fe_(2.08)In_(2.92) alloy

The isothermal section of the Ho-Fe-In system at 773 K has been constructed by X-ray powder diffraction.One known structure ternary compound Er_(12)Fe_(2) In_(3)-type Ho_(12)Fe_(2) In_(3) has been confirmed.At the same time,solid solutions are not detected in Ho-Fe-In system at 773 K.The magnetic transition and magnetocaloric effect of Ho_(12)Fe_(2.08)In_(2.92) alloy with Er_(12)Fe_(2) In_(3)-type structure were investigated by magnetic susceptibility and isothermal magnetization measurements.One normal antiferromagnetic-paramagnetic transition and another abnormal one are discovered at 18 and 76 K in ground state,respectively.Owing to a first-order field-induced metamagnetic transition(antiferromagnetic-ferromagnetic) at/below the Neel temperature of 18 K),the negative entropy changes are observed at corresponding temperature.There is only a second-order ferromagnetic-paramagnetic transition near Curie temperature(TC),the maximum entropy change(Δ_(Smax)) values are-6.14 J·kg^(-1)·K^(-1) at 3 K and 7.88 J·kg^(-1)·K^(-1) at 28 K in a field range of 0-7 T.The reversible relative cooling power corresponding to negative entropy change can reach about 600 J·kg^(-1) in an wide operating temperature region Δ_(Tcycl)=74 K from 16 to90 K,which suggests that Ho_(12)Fe_(2.08)In_(2.92) could be a potential material for magnetic refrigeration in the corresponding temperature range.

A Linear Programming-Based Reinforcement Learning Mechanism for Incomplete-Information Games

Dear Editor,Recently, with the development of artificial intelligence, game intelligence decision-making has attracted more and more attention.In particular, incomplete-information games(IIG) have gradually become a new research focus, where players make decisions without sufficient information, such as the opponent's strategies or preferences.