We study the dynamic cavity method for dilute kinetic Ising models with synchronous update rules. For the parallel update rule we find for fully asymmetric models that the dynamic cavity equations reduce to a Markovia...We study the dynamic cavity method for dilute kinetic Ising models with synchronous update rules. For the parallel update rule we find for fully asymmetric models that the dynamic cavity equations reduce to a Markovian dynamics of the (time-dependent) marginal probabilities. For the random sequential update rule, also an instantiation of a synchronous update rule, we find on the other hand that the dynamic cavity equations do not reduce to a Markovian dynamics, unless an additional assumption of time factorization is introduced. For symmetric models we show that a fixed point of ordinary Belief propagation is also a fixed point of the dynamic cavity equations in the time factorized approximation. For clarity, the conclusions of the paper are formulated as three lemmas.展开更多
Resonant-cavity technique was introduced to measure the permittivity and loss tangent of low-loss dielectrics. The dielectric properties at 9-10 GHz are measured accurately at the temperature up to 800 ℃ by the reson...Resonant-cavity technique was introduced to measure the permittivity and loss tangent of low-loss dielectrics. The dielectric properties at 9-10 GHz are measured accurately at the temperature up to 800 ℃ by the resonant cavity technique. The only electrical parameters that need to be measured are quality factors （Q） and resonant length （L） of resonant cavity loaded and unloaded with dielectric sample. Moreover, the error caused by thermal expansion effect was resolved by error analysis and experimental calibration.展开更多
In order to study cavitation characteristics of a 2-D hydrofoil, the method that combines nonlinear cavitation model and mixed-iteration is used to predict and analyze the cavitation performance of hydrofoils. The cav...In order to study cavitation characteristics of a 2-D hydrofoil, the method that combines nonlinear cavitation model and mixed-iteration is used to predict and analyze the cavitation performance of hydrofoils. The cavitation elements are nonlinearly disposed based on the Green formula and perturbation potential panel method. At the same time, the method that combines cavity shape for fixed cavity length （CSCL） iteration and cavity shape for fixed cavitation number （CSCN） iteration is used to work out the thickness and length of hydrofoil cavitations. Through analysis of calculation results, it can be concluded that the jump of pressure and velocity potentially exist between cavitation end area and non-cavitations area on suction surface when cavitation occurs on hydrofoil. In certain angles of attack, the cavitation number has a negative impact on the length of cavitations. And under the same angle of attack and cavitation number, the bigger the thickness of the hydrofoil, the shorter the cavitations length.展开更多
Compressed sensing is a new signM acquisition method that acquires signal in a compressed form and then recovers the signal by the use of computational tools and techniques. This means fewer measurements of signal are...Compressed sensing is a new signM acquisition method that acquires signal in a compressed form and then recovers the signal by the use of computational tools and techniques. This means fewer measurements of signal are needed and thus it will save huge amount of time and storage space. We, in this paper, consider the compressed sensing of sparse integer-valued signal （referred as ＂q-states signal＂ throughout the paper）. In order to accelerate the speed of reconstruction, we adopt the sparse rather than dense measurement matrices. Using methods and tools developed in statistical physics, we locate the reconstruction limit for Lo-reconstruction method and propose a belief propagation- based algorithm that can deal with instance with large size and its typical reconstruction performance are also analyzed.展开更多
Ergodicity of a spin-glass is broken at low temperatures;the system is trapped in one of many ergodicconfigurational domains.Transitions between different ergodic domains are achievable through a heating-annealingproc...Ergodicity of a spin-glass is broken at low temperatures;the system is trapped in one of many ergodicconfigurational domains.Transitions between different ergodic domains are achievable through a heating-annealingprocedure.If this experiment is repeated infinite times,all ergodic configurational domains will be visited with frequencesthat decreasing exponentially with their free energies.The mean free energy density of a spin-glass system on a randomgraph is calculated based on this free energy Boltzmann distribution in the present work,by means of the cavity approach.展开更多
Based on simple combinatorial arguments,we formulate a generalized cavity method where the Random Overlap Structure(ROSt)probability space of Aizenmann,Sims and Starr is obtained in a constructive way,and we use it to...Based on simple combinatorial arguments,we formulate a generalized cavity method where the Random Overlap Structure(ROSt)probability space of Aizenmann,Sims and Starr is obtained in a constructive way,and we use it to give a simplified derivation of the Parisi formula for the free energy of the Sherrington–Kirkpatrick model.展开更多
Dielectric data for volcanic scoria and basalt on the earth at microwave frequency are extremely sparse, and also crucial for volcanic terrains imaging, and development. In consideration of their similarity to lunar r...Dielectric data for volcanic scoria and basalt on the earth at microwave frequency are extremely sparse, and also crucial for volcanic terrains imaging, and development. In consideration of their similarity to lunar regolith (soils and rocks) in chemical and mineral composition, the dielectric data is significative for passive and active microwave remote sensing on the Moon. This study provides the data about the dielectric properties of three kinds of scoria and two kinds of basalt in China. The method put forward in this paper is also applicable for measuring the dielectric properties of dry rocks and other granular ground materials with low complex dielectric constants. Firstly, the authors measured the e' and tanδ values of strip specimens prepared from the mixture of scoria or basalt powder and polythene with the resonant cavity perturbation method at 9370 MHz. Secondly, from the ε' and tanδ values of the mixture, the ε' s and tanδ s values of solid scoria and basalt were calculated using Lichtenecker's mixture formulae. Finally, the effective complex dielectric constants, ε' e and tanδ e , of scoria at different bulk densities were calculated. The results have shown that the ε' s and tanδ s values of all solid basaltic materials measured (both solid basaltic scoria or basalt) are approximately 7 and 0.05, respectively. With increasing bulk density of scoria, the ε' c and tanδ e values of scoria increase significantly.展开更多
A semi-analytical/numerical model based on the multiple scattering （MS） method has been established for analyzing the effect of acoustic performance on main energy attenua- tion mechanism in viscoelastic coating con...A semi-analytical/numerical model based on the multiple scattering （MS） method has been established for analyzing the effect of acoustic performance on main energy attenua- tion mechanism in viscoelastic coating containing axisymmetric cavities. The basic functions of stress and displacement of the axisymmetric cavity surface are derived in the system of spheri- cal coordinates. The transition matrix between the incident wave and the scattering wave are obtained by the numerical integral of the basic functions of the cavity surface. The reflection, transmission and absorption performance of viscoelastic materials containing periodic cavities are calculated using the MS method and the wave propagating theory of the multi-layered medium. The results indicate that low frequency energy is mainly attenuated through cavity resonance. The resonant properties are found to be very sensitive to the boundary conditions. The coupling of the double-cavity is capable of extending the absorption to even lower fre- quencies. The absorption performance of the viscoelastic coating in the high frequency range is independent of the backing material. Its energy attenuation depends mainly on acoustic properties of cavity scattering and mode conversion.展开更多
基金Supported by the Academy of Finland as part of Its Finland Distinguished Professor Program, Project 129024/Aurellin part by the Project of Knowledge Innovation Program (PKIP) of Chinese Academy of Sciences under Grant No. KJCX2.YW.W10
文摘We study the dynamic cavity method for dilute kinetic Ising models with synchronous update rules. For the parallel update rule we find for fully asymmetric models that the dynamic cavity equations reduce to a Markovian dynamics of the (time-dependent) marginal probabilities. For the random sequential update rule, also an instantiation of a synchronous update rule, we find on the other hand that the dynamic cavity equations do not reduce to a Markovian dynamics, unless an additional assumption of time factorization is introduced. For symmetric models we show that a fixed point of ordinary Belief propagation is also a fixed point of the dynamic cavity equations in the time factorized approximation. For clarity, the conclusions of the paper are formulated as three lemmas.
文摘Resonant-cavity technique was introduced to measure the permittivity and loss tangent of low-loss dielectrics. The dielectric properties at 9-10 GHz are measured accurately at the temperature up to 800 ℃ by the resonant cavity technique. The only electrical parameters that need to be measured are quality factors （Q） and resonant length （L） of resonant cavity loaded and unloaded with dielectric sample. Moreover, the error caused by thermal expansion effect was resolved by error analysis and experimental calibration.
基金Supported by the National Natural Science Foundation of China （Grant No. 41176074） China Postdoctoral Science Foundation （Grant No.2012M512133） Specialized Research Fund for the Doctoral Program of Higher Education （Grant No.20102304120026）
文摘In order to study cavitation characteristics of a 2-D hydrofoil, the method that combines nonlinear cavitation model and mixed-iteration is used to predict and analyze the cavitation performance of hydrofoils. The cavitation elements are nonlinearly disposed based on the Green formula and perturbation potential panel method. At the same time, the method that combines cavity shape for fixed cavity length （CSCL） iteration and cavity shape for fixed cavitation number （CSCN） iteration is used to work out the thickness and length of hydrofoil cavitations. Through analysis of calculation results, it can be concluded that the jump of pressure and velocity potentially exist between cavitation end area and non-cavitations area on suction surface when cavitation occurs on hydrofoil. In certain angles of attack, the cavitation number has a negative impact on the length of cavitations. And under the same angle of attack and cavitation number, the bigger the thickness of the hydrofoil, the shorter the cavitations length.
文摘Compressed sensing is a new signM acquisition method that acquires signal in a compressed form and then recovers the signal by the use of computational tools and techniques. This means fewer measurements of signal are needed and thus it will save huge amount of time and storage space. We, in this paper, consider the compressed sensing of sparse integer-valued signal （referred as ＂q-states signal＂ throughout the paper）. In order to accelerate the speed of reconstruction, we adopt the sparse rather than dense measurement matrices. Using methods and tools developed in statistical physics, we locate the reconstruction limit for Lo-reconstruction method and propose a belief propagation- based algorithm that can deal with instance with large size and its typical reconstruction performance are also analyzed.
文摘Ergodicity of a spin-glass is broken at low temperatures;the system is trapped in one of many ergodicconfigurational domains.Transitions between different ergodic domains are achievable through a heating-annealingprocedure.If this experiment is repeated infinite times,all ergodic configurational domains will be visited with frequencesthat decreasing exponentially with their free energies.The mean free energy density of a spin-glass system on a randomgraph is calculated based on this free energy Boltzmann distribution in the present work,by means of the cavity approach.
基金I wish to thank Amin Coja-Oghlan(Goethe University,Frankfurt)for sharing his views on graph theory and replica symmetry breaking,which deeply influenced this work.I also wish to thank Giorgio Parisi,Pan Liming,Francesco Guerra,Pietro Caputo,Nicola Kistler,Demian Battaglia,Francesco Concetti and Riccardo Balzan for interesting discussions and suggestions.This project has received funding from the European Research Council(ERC)under the European Union's Horizon 2020 research and innovation programme(Grant Agreement No[694925]).
文摘Based on simple combinatorial arguments,we formulate a generalized cavity method where the Random Overlap Structure(ROSt)probability space of Aizenmann,Sims and Starr is obtained in a constructive way,and we use it to give a simplified derivation of the Parisi formula for the free energy of the Sherrington–Kirkpatrick model.
基金the National Natural Science Foundation of China(Grant No.40473036and 40373037) the project of knowledge-innovation program of the Chinese Academy of Sciences(Grant No.KZCX2-115).
文摘Dielectric data for volcanic scoria and basalt on the earth at microwave frequency are extremely sparse, and also crucial for volcanic terrains imaging, and development. In consideration of their similarity to lunar regolith (soils and rocks) in chemical and mineral composition, the dielectric data is significative for passive and active microwave remote sensing on the Moon. This study provides the data about the dielectric properties of three kinds of scoria and two kinds of basalt in China. The method put forward in this paper is also applicable for measuring the dielectric properties of dry rocks and other granular ground materials with low complex dielectric constants. Firstly, the authors measured the e' and tanδ values of strip specimens prepared from the mixture of scoria or basalt powder and polythene with the resonant cavity perturbation method at 9370 MHz. Secondly, from the ε' and tanδ values of the mixture, the ε' s and tanδ s values of solid scoria and basalt were calculated using Lichtenecker's mixture formulae. Finally, the effective complex dielectric constants, ε' e and tanδ e , of scoria at different bulk densities were calculated. The results have shown that the ε' s and tanδ s values of all solid basaltic materials measured (both solid basaltic scoria or basalt) are approximately 7 and 0.05, respectively. With increasing bulk density of scoria, the ε' c and tanδ e values of scoria increase significantly.
基金supported by the National Nature Science Foundation of China(11104310)the 973 National key Basic Research Program of China(2013CB632900)the 863 National High Technology Program of China(2011AA11A103)
文摘A semi-analytical/numerical model based on the multiple scattering （MS） method has been established for analyzing the effect of acoustic performance on main energy attenua- tion mechanism in viscoelastic coating containing axisymmetric cavities. The basic functions of stress and displacement of the axisymmetric cavity surface are derived in the system of spheri- cal coordinates. The transition matrix between the incident wave and the scattering wave are obtained by the numerical integral of the basic functions of the cavity surface. The reflection, transmission and absorption performance of viscoelastic materials containing periodic cavities are calculated using the MS method and the wave propagating theory of the multi-layered medium. The results indicate that low frequency energy is mainly attenuated through cavity resonance. The resonant properties are found to be very sensitive to the boundary conditions. The coupling of the double-cavity is capable of extending the absorption to even lower fre- quencies. The absorption performance of the viscoelastic coating in the high frequency range is independent of the backing material. Its energy attenuation depends mainly on acoustic properties of cavity scattering and mode conversion.
