The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, we propose a new topological index, which is a numerical descriptor that characterizes survivable network topologies. A monotonically decreasing power law relationship can be found between this index and the total capacity allocation in the network. The new topological index is calculated based on the algebraic connectivity, which is adopted from spectral graph theory, more specifically...
The main purpose of this paper is to explore the complexity of the logistics industry from the demand factors and supply factors, and analyze the key factors affecting industry development. A PCA model is applied to assess which influencing factors revealed higher logistics output. The data is limited to Henan province from 2002 to 2008, and 17 indexes are selected to reflect the output-input. On...
A new method named prediction-correction homotopy method is proposed to calculate Hopf bifurcation points associated with the parameter dependent differential algebraic equations (DAE) which are used to model power systems dynamics. It uses the secant prediction method to track the Hopf bifurcation homotopy path. Compared with the tangent prediction method, the computation load is much less because...
In network survivability design, it is important to be able to differentiate network topologies by means of a quantitative measure that would indicate different levels of robustness of these topologies to failures of their nodes and links. Ideally, such a measure should be sensitive to the existence of nodes or links which are more critical than others, for example, if their failures can disconnect...
In studies of survivable networks, it is important to be able to differentiate network topologies by means of a robust numerical measure that indicates the levels of immunity of these topologies to failures of their nodes and links. Ideally, such a measure should be sensitive to the existence of nodes or links which are more important than others, for example, if their failures cause the network's...
In this paper, instead of using the average nodal degree metric, we suggest to use the Fiedler value metric, adopted from the spectral graph theory, namely the 2nd smallest eigenvalue of the Laplacian matrix of a given network topology, to quantify network connectivity in studies of spare capacity allocation problem. Ideally, such a robustness measure should be sensitive to the existence of nodes...
In this treatise, we propose a novel singular value decomposition (SVD) based downlink (DL) multiuser MIMO system, which takes into account the specific characteristics of the individual users channel matrix, instead of treating all the users channels jointly, as in the traditional minimum mean square error (MMSE) or zero-forcing (ZF) multiuser transmission (MUT) technique. Furthermore, two different...
In this contribution projection approximation subspace tracking using deflation (PASTD) is investigated in the context of MIMO transmit preprocessing systems by exploiting the specific property of time division duplexing (TDD) techniques that the uplink and downlink channels are similar, since they both use the same carrier frequency. Hence the channel estimated from the received signal can also be...
Eigen-beamforming is capable of attaining attractive performance gains in the context of multiple-input multiple-output (MIMO) systems, provided that accurate channel state information (CSI) is available. However, when a realistic pilot-based channel predictor is used for acquiring the CSI, a significant performance degradation may be imposed by the phase-ambiguity inherent in the estimated eigen-vectors...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.