A UNIFORMLY AND OPTIMALLY ACCURATE METHOD FOR THE KLEIN-GORDON-ZAKHAROV SYSTEM IN SIMULTANEOUS HIGH-PLASMA-FREQUENCY AND SUBSONIC LIMIT REGIME *

We present a uniformly and optimally accurate numerical method for solving the Klein-Gordon-Zakharov (KGZ) system with two dimensionless parameters 0 < ε ≤ 1 and 0 < γ ≤ 1, which are inversely proportional to the plasma frequency and the acoustic speed, respectively. In the simultaneous high-plasma-frequency and subsonic limit regime, i.e. ε < γ → 0 + , the KGZ system collapses to a cubic Schrödinger equation, and the solution propagates waves with O(ε 2)-wavelength in time and meanwhile contains rapid outgoing initial layers with speed O(1/γ) in space due to the incompatibility of the initial data. By presenting a multiscale decomposition of the KGZ system, we propose a multiscale time integrator Fourier pseduospectral method which is explicit, efficient and uniformly accurate for solving the KGZ system for all 0 < ε < γ ≤ 1. Numerical results are reported to show the efficiency and accuracy of scheme. Finally, the method is applied to investigate the convergence rates of the KGZ system to its limiting models when ε < γ → 0 +

Alternating Local Enumeration (TnALE): Solving Tensor Network Structure Search with Fewer Evaluations

Tensor network (TN) is a powerful framework in machine learning, but selecting a good TN model, known as TN structure search (TN-SS), is a challenging and computationally intensive task. The recent approach TNLS~\cite{li2022permutation} showed promising results for this task, however, its computational efficiency is still unaffordable, requiring too many evaluations of the objective function. We propose TnALE, a new algorithm that updates each structure-related variable alternately by local enumeration, \emph{greatly} reducing the number of evaluations compared to TNLS. We theoretically investigate the descent steps for TNLS and TnALE, proving that both algorithms can achieve linear convergence up to a constant if a sufficient reduction of the objective is \emph{reached} in each neighborhood. We also compare the evaluation efficiency of TNLS and TnALE, revealing that $\Omega(2^N)$ evaluations are typically required in TNLS for \emph{reaching} the objective reduction in the neighborhood, while ideally $O(N^2R)$ evaluations are sufficient in TnALE, where $N$ denotes the tensor order and $R$ reflects the \emph{``low-rankness''} of the neighborhood. Experimental results verify that TnALE can find practically good TN-ranks and permutations with vastly fewer evaluations than the state-of-the-art algorithms.Comment: Accepted by ICML2023, pre-printed versio

Optimization of Induction Quenching Processes for HSS Roll Based on MMPT Model

To improve the comprehensive performance of high speed steel (HSS) cold rolls, the induction hardening processes were analyzed by numerical simulation and experimental research. Firstly, a modified martensitic phase transformation (MMPT) model of the tested steel under stress constraints was established. Then, the MMPT model was fed into DEFORM to simulate the induction quenching processes of working rolls based on an orthogonal test design and the optimal dual frequency of the induction quenching process was obtained. The results indicate that the depth of the roll’s hardened layer increases by 32.5% and the axial residual tensile stress also becomes acceptable under the optimized process. This study provides guidance for studying phase transformation laws under stress constraints and the optimization of complex processes in an efficient manner

Alternating Local Enumeration (TnALE): solving tensor network structure search with fewer evaluations

Tensor network (TN) is a powerful framework in machine learning, but selecting a good TN model, known as TN structure search (TN-SS), is a challenging and computationally intensive task. The recent approach TNLS (Li et al., 2022) showed promising results for this task. However, its computational efficiency is still unaffordable, requiring too many evaluations of the objective function. We propose TnALE, a surprisingly simple algorithm that updates each structure-related variable alternately by local enumeration, greatly reducing the number of evaluations compared to TNLS. We theoretically investigate the descent steps for TNLS and TnALE, proving that both the algorithms can achieve linear convergence up to a constant if a sufficient reduction of the objective is reached in each neighborhood. We further compare the evaluation efficiency of TNLS and TnALE, revealing that Ω(2K) evaluations are typically required in TNLS for reaching the objective reduction, while ideally O(KR) evaluations are sufficient in TnALE, where K denotes the dimension of search space and R reflects the “low-rankness” of the neighborhood. Experimental results verify that TnALE can find practically good TN structures with vastly fewer evaluations than the state-of-the-art algorithms.Fil: Li, Chao. Riken Aip; JapónFil: Zeng, Junhua. Riken Aip; Japón. Guangdong University of Technology; ChinaFil: Li, Chunmei. Riken Aip; Japón. Harbin Engineering University; ChinaFil: Caiafa, César Federico. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Zhao, Qibin. Riken Aip; Japón40th International Conference on Machine LearningHonoluluEstados UnidosInternational Council for Machinery Lubricatio

Formability of a HSAS Based on Hot Processing Maps and Texture Analyses

Aiming to improve the formability of a HSAS Docol 1500 Bor, hot processing maps were obtained based on Prasad, Babu and Murty instability criteria. The hot processing maps based on the above instability criteria are similar and the explanation of its similarity is given. Recrystallization and misorientation in typical quenched specimens were observed by using SEM with a EBSD system. It was found that the fraction values of HAGBs in quenched martensite are all below 0.4 under experimental conditions. Flow location bands occurs at lower deformation temperatures and higher strain rates. The textures in martensite mainly include ⟨110⟩ / / ND and ⟨110⟩ / / RD components. Based on N-W OR, the textures in deformed austenite are mostly ⟨111⟩ / / ND and ⟨112⟩ / / RD⟩ components. Prasad and Babu instability criteria are more conservative than Murty instability criterion in obtaining the processing maps of the tested steel. To reduce the anisotropy of quenched workpieces because of the textures at room temperature, the quenching temperature in the stamping process of the tested steel should be lower

Research on Influences of Transient High IOP during LASIK on Retinal Functions and Ultrastructure

Objectives. To study the influences of transient high intraocular pressure(IOP) during LASIK on retinal functions and ultrastructure. Methods. Thirty-two New Zealand white rabbits were randomly divided into normal control, experimental control, negative suction 20 s and negative suction 3 min groups. The experimental control group was treated only by laser. Rabbit eyes received suction for different periods of time (20 s, 3 min) by negative pressure generator in different groups. The changes of neuro-optic and retinal ultrastructure were observed under electron and light microscopes; retinal neurofunctional changes were observed with flash-visual evoked potential (F-VEP) and flash-electroreinogram (F-ERG). Results. There was no obvious change in optic nerve, retina, ERG a-wave and b-wave in normal control and experimental control groups. There were slight changes in tissues of optic nerve and retina at various times of suction 20 s compared with control group, and a sharp change in suction 3 min group within 14d after operation, but these changes recovered at 28d . Amplitude of ERG b-wave observed at different time will decrease with suction periods prolonged. It can recover to normal level with the prolonged recovery periods. Amplitude and incubation period of ERG a-wave and VEP-P did not change significantly after different duration of suction. Conclusions. The transient high IOP during LASIK might have influence on retinal function and ultrastructure, but these changes were reversible

EFFECTS OF GAN LIAN YU PING FENG POWDER ON THE ANTIBODY TITERS TO INFECTIOUS LARYNGOTRACHEITIS VACCINE AND SOME NONSPECIFIC IMMUNE INDEXES IN CHICKENS

The study was conducted in order to investigate the immuno-enhancing property of the Chinese herbal formula, Gan lian Yu ping feng powder. Three hundred and thirty six 45-day-old chicks were randomly divided into eight groups. The chicks in groups A, B, C were orally given 0.25 g/mL(low-),0.5 g/mL(middle-) and 1.0 g/mL(high) dose of Gan lian Yu ping feng powder in the drinking water respectively for 3 days consecutively. They were then immunised with infectious laryngotracheitis vaccine (ILTV) on the 4th day. Groups D, E, F were given 0.25 g/mL,0.5 g/mL and 1.0 g/mL dose of Gan lian Yu ping feng powder respectively after the immunisation for three days consecutively. Group G was Wen du qing (a government approved herbal product for ILT) control group and group H was blank control group. At 52、59、73、87 days of age, 8 chicks of each group were selected randomly for blood sampling to determine the levels of IFN-γ, IL-4 and the antibody of ILT. Then the chickens were sacrificed, with the thymus, spleen and Bursa of Fabricius being weighed for the calculation of immune organ indexes. The results showed that high and middle dosages of Gan lian Yu ping feng powder given at the day before immunisation and 3 days after immunisation elevated not only the contents of IFN-γ, the antibody titers of ILT (

Fast implementation of two-dimensional singular spectrum analysis for effective data classification in hyperspectral imaging

Although singular spectrum analysis (SSA) has been successfully applied for data classification in hyperspectral remote sensing, it suffers from extremely high computational cost, especially for 2D-SSA. As a result, a fast implementation of 2D-SSA namely F-2D-SSA is presented in this paper, where the computational complexity has been significantly reduced with a rate up to 60%. From comprehensive experiments undertaken, the effectiveness of F-2D-SSA is validated producing a similar high-level of accuracy in pixel classification using support vector machine (SVM) classifier, yet with a much reduced complexity in comparison to conventional 2D-SSA. Therefore, the introduction and evaluation of F-2D-SSA completes a series of studies focused on SSA, where in this particular research, the reduction in computational complexity leads to potential applications in mobile and embedded devices such as airborne or satellite platforms