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411.
TLS和LS问题的比较   总被引:4,自引:0,他引:4  
刘永辉  魏木生 《计算数学》2003,25(4):479-492
There are a number of articles discussing the total least squares(TLS) and the least squares(LS) problems.M.Wei(M.Wei, Mathematica Numerica Sinica 20(3)(1998),267-278) proposed a new orthogonal projection method to improve existing perturbation bounds of the TLS and LS problems.In this paper,wecontinue to improve existing bounds of differences between the squared residuals,the weighted squared residuals and the minimum norm correction matrices of the TLS and LS problems.  相似文献   
412.
The semilocal convergence of a family of Chebyshev-Halley like iterations for nonlinear operator equations is studied under the hypothesis that the first derivative satisfies a mild differentiability condition. This condition includes the usual Lipschitz condition and the H?lder condition as special cases. The method employed in the present paper is based on a family of recurrence relations. The R-order of convergence of the methods is also analyzed. As well, an application to a nonlinear Hammerstein integral equation of the second kind is provided. Furthermore, two numerical examples are presented to demonstrate the applicability and efficiency of the convergence results.  相似文献   
413.
With the increasing number of IP cores that are integrated into a system-on-chip (SoC), the interconnection between different cores has become crucial to achieve high performance. Optical Network-on-Chip (ONoC) has emerged as a high efficiency interconnection for the future generation of many-core SoCs. ONoC can achieve high bandwidth, low delay, low interference, and low power consumption, which makes it promising in future SoC design. In this paper, a new optical interconnection is proposed to interconnect the IP cores and caches in a chip. It is constructed by levels of rings. All the IP cores and corresponding caches are arranged in the rings respectively. The floorplan is carefully designed with consideration about reducing waveguide crossings. A new optical router is proposed and its insertion losses are analyzed. Finally, a simulator based on OPNET is carried out to evaluate the network performance in terms of End-to-End delay and throughput. The simulation results demonstrate that the proposed architecture can implement well and achieve good performance.  相似文献   
414.
In this paper we prove the existence of global attractor for the generalized dissipative KdV equation onR, and give an upper bound for its hausdorff and fractal dimensions.  相似文献   
415.
In this paper we discuss the existence and global attractivity of k-almost automorphic sequence solution of a model of cellular neural networks.We consider the corresponding difference equation analogue of the model system using suitable discretization method and obtain certain conditions for the existence of solution.Almost automorphic function is a good generalization of almost periodic function.This is the first paper considering such solutions of the neural networks.  相似文献   
416.
The coordination structure determines the electrocatalytic performances of single atom catalysts (SACs), while it remains a challenge to precisely regulate their spatial location and coordination environment. Herein, we report a universal sub-nanoreactor strategy for synthesis of yolk-shell MoS2 supported single atom electrocatalysts with dual-anchored microenvironment of vacancy-enriched MoS2 and intercalation carbon toward robust hydrogen-evolution reaction. Theoretical calculations reveal that the “E-Lock” and “E-Channel” are conducive to stabilize and activate metal single atoms. A group of SACs is subsequently produced with the assistance of sulfur vacancy and intercalation carbon in the yolk-shell sub-nanoreactor. The optimized C−Co−MoS2 yields the lowest overpotential (η10=17 mV) compared with previously reported MoS2-based electrocatalysts to date, and also affords a 5–9 fold improvement in activity even comparing with those as-prepared single-anchored analogues. Theoretical results and in situ characterizations unveil its active center and durability. This work provides a universal pathway to design efficient catalysts for electro-refinery.  相似文献   
417.
418.
The development of a new electrolytic water hydrogen production coupling system is the key to realize efficient and low-cost hydrogen production and promote its practical application. Herein, a green and efficient electrocatalytic biomass to formic acid (FA) coupled hydrogen production system has been developed. In such a system, carbohydrates such as glucose are oxidized to FA using polyoxometalates (POMs) as the redox anolyte, while H2 is evolved continuously at the cathode. Among them, the yield of glucose to FA is as high as 62.5 %, and FA is the only liquid product. Furthermore, the system requires only 1.22 V to drive a current density of 50 mA cm−2, and the Faraday efficiency of hydrogen production is close to 100 %. Its electrical consumption is only 2.9 kWh Nm−3 (H2), which is only 69 % of that of traditional electrolytic water. This work opens up a promising direction for low-cost hydrogen production coupled with efficient biomass conversion.  相似文献   
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