We apply a recently developed approach (Liaw 2013 J. Stat. Phys. 153 1022-38) to study the existence of extended states for the three-dimensional discrete random Schrodinger operator at small disorder. The conclusion ...
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We apply a recently developed approach (Liaw 2013 J. Stat. Phys. 153 1022-38) to study the existence of extended states for the three-dimensional discrete random Schrodinger operator at small disorder. The conclusion of delocalization at small disorder agrees with other numerical and experimental observations (see e.g. (Lagendijk et al 2009 Phys. Today 82 24-29)). Further the work furnishes a verification of the numerical approach and its implementation. Not being based on scaling theory, this method eliminates problems due to boundary conditions, common to previous numerical methods in the field. At the same time, as with any numerical experiment, one cannot exclude finite-size effects with complete certainty. Our work can be thought of as a new and quite different use of lanczos' algorithm;a posteriori tests how that the orthogonality loss is very small. We numerically track the 'bulk distribution' (here: the distribution of where we most likely find an electron) of a wave packet initially located at the origin, after iterative application of the discrete random Schrodinger operator.
Identifying the most important nodes according to specific centrality indices is an important issue in network analysis. Node metrics based on the computation of functions of the adjacency matrix of a network were def...
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Identifying the most important nodes according to specific centrality indices is an important issue in network analysis. Node metrics based on the computation of functions of the adjacency matrix of a network were defined by Estrada and his collaborators in various papers. This paper describes a MATLAB toolbox for computing such centrality indices using efficient numerical algorithms based on the connection between the lanczos method and Gauss-type quadrature rules.
Single-layer spherical reticulated shells are typical roof structures for the gymnasiums. The center-hung scoreboard (CHS) is large weight display device which is usually suspended on the roof of the gymnasium. The ef...
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Single-layer spherical reticulated shells are typical roof structures for the gymnasiums. The center-hung scoreboard (CHS) is large weight display device which is usually suspended on the roof of the gymnasium. The effect of the CHS on the dynamic characteristics and seismic responses of the single-layer spherical reticulated shell (SPRS) is not fully clear. In this paper, the effect of the CHS on the SPRS under vertical seismic action is investigated. Two kinds of FE models are built with Abaqus software, including the flexibly suspended model and the simplified model. In a simplified model, the CHS is simplified as four fixed masses on the four CHS suspension nodes. The dynamic explicit method is used for the seismic responses, and the lanczos method is used for the dynamic characteristics. The influence of the CHS weight and the sling length of on dynamic characteristics and seismic responses are analysed. It turns out that in the flexibly suspended model, the first three vibration modes are free swing of the CHS, and the CHS weight and the sling length have a significant impact on the fourth and subsequent modes. The length of the sling has a large impact on some low-order frequencies, but has little impact on the high-order frequencies. Compared with the simplified model, the axial forces of some structural members and some nodal acceleration in the flexibly suspended model under vertical seismic motions would increase by as high as 523% and 564%, respectively. It turns out that the seismic responses of the SPRS would be underestimated if a simplified model is used for analysis. The region in the central of the SPRS, the hoop members of the SPRS, and the support platform are the most affected regions in terms of both axial force and nodal acceleration.
Lucent TechnologiesThis paper discusses the analysis of large linear electrical networks consisting of passive components, such as resistors, capacitors, inductors, and transformers. Such networks admit a symmetric fo...
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ISBN:
(纸本)9780818675973
Lucent TechnologiesThis paper discusses the analysis of large linear electrical networks consisting of passive components, such as resistors, capacitors, inductors, and transformers. Such networks admit a symmetric formulation of their circuit equations. We introduce SyPVL, an efficient and numerically stable algorithm for the computation of reduced-order models of large, linear, passive networks. SyPVL represents the specialization of the more general PVL algorithm, to symmetric problems. Besides the gain in efficiency over PVL, SyPVL also preserves the symmetry of the problem, and, as a consequence, can often guarantee the stability of the resulting reduced-order models. Moreover, these reduced-order models can be synthesized as actual physical circuits, thus facilitating compatibility with existing analysis tools. The application of SyPVL is illustrated with two interconnect-analysis examples.
As the positioning accuracy of GNSS systems will degrade in the presence of electromagnetic interference, jamming detection becomes pivotal part in high-precision wireless communication systems which is conventionally...
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ISBN:
(纸本)9781479989218
As the positioning accuracy of GNSS systems will degrade in the presence of electromagnetic interference, jamming detection becomes pivotal part in high-precision wireless communication systems which is conventionally accomplished by energy statistics or time-frequency transformation. In this paper, we present the spatial-frequency adaptive processing (SFAP) method which will achieve highly detecting resolution through the distribution of eigenvalues in frequency domain, and compared to the conventional methods the SFAP can accurately detect the bandwidth of multiple signals. The application of fast subspace decomposition (FSD) using lanczos algorithm iteratively implements the eigenvalue-decomposition with lower complexity while the source enumeration is estimated simultaneously. Moreover, the proposed method still works well even in the presence of weaker clutter or stochastic errors. Computer simulation results confirm the robustness of the detecting method.
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