Generalized eigen-analysis of SSO based on novel structure-preserving LDAE model

A novel structure-preserving linearized differential and algebraic equations (LDAE) model for small signal eigenanalysis of power system SSO is proposed in this paper. LDAE models of various power system components are formed first. Modularized establishment of entire system model is then conducted quickly according to the network topology. Generalized eigenvalue & eigenvector calculation, and eigenvalue sensitivity analysis based on the LDAE model are applied thereafter. The effectiveness of the proposed LDAE model based SSO analysis approach is verified through computer test results. The LDAE-based SSO study model and the corresponding generalized eigen-analysis approach pave the way for power system SSO study with HVDC transmission and/or FACTS devices without eliminating any algebraic variables. © 2005 IEEE.published_or_final_versio

Analysis approach of SSO based on LDAE model

A linearized differential and algebraic equations (LDAE) model for both eigen-analysis and complex torque coefficient (CTC) calculation of power system subsynchronous oscillation (SSO) is proposed in this paper. The LDAE model for SSO study is derived at first. Generalized eigen-analysis and CTC calculation based on the LDAE model are presented thereafter. The effectiveness of the proposed LDAE model based SSO analysis approaches are verified through computer test results. The LDAEmodel-based SSO study approach suggested in this paper paves the way for SSO study with HVDC transmission and/or FACTS devices without eliminating their algebraic variables, which can obtain more valuable information.published_or_final_versio

Decentralized power system voltage stability proximity indicator based on local bus information

In this paper, a decentralized power system voltage stability proximity indicator is presented. This indicator can consider the occurrence of not only the saddle node bifurcation but also the Hopf bifurcation, while only local bus information is needed for the decentralized voltage stability monitoring. The results of two power system examples discover the possibility of on-line decentralized voltage instability / collapse assessment.published_or_final_versio

Discovering Debtor Patterns of Centrelink Customers

Data mining is currently becoming an increasingly hot research field, but a large gap still remains between the research of data mining and its application in real-world business. As one of the largest data users in Australia, Centrelink has huge volume of data in data warehouse and tapes. Based on the available data, Centrelink is seeking to find underlying patterns to be able to intervene earlier to prevent or minimize debt. To discover the debtor patterns of Centrelink customers and bridge the gap between data mining research and application, we have done a project on improving income reporting to discover the patterns of those customers who were or are in debt to Centrelink. Two data models were built respectively for demographic data and activity data, and decision tree and sequence mining were used respectively to discover demographic patterns and activity sequence patterns of debtors. The project produced some potentially interesting results, and paved the way for more data mining applications in Centrelink in near future. © 2006, Australian Computer Society, Inc

λϕ4\lambda\phi^4 model and Higgs mass in standard model calculated by Gaussian effective potential approach with a new regularization-renormalization method

Basing on new regularization-renormalization method, the $\lambda\phi^4$ model used in standard model is studied both perturbatively and nonperturbatively (by Gaussian effective potential). The invariant property of two mass scales is stressed and the existence of a (Landau) pole is emphasized. Then after coupling with the SU(2)$\times$U(1) gauge fields, the Higgs mass in standard model (SM) can be calculated as $m_H\approx$138GeV. The critical temperature ($T_c$) for restoration of symmetry of Higgs field, the critical energy scale ($\mu_c$, the maximum energy scale under which the lower excitation sector of the GEP is valid) and the maximum energy scale ($\mu_{max}$, at which the symmetry of the Higgs field is restored) in the standard model are $T_c\approx$476 GeV, $\mu_c\approx 0.547\times 10^{15}$GeV and $\mu_{\max}\approx 0.873 \times 10^{15}$ GeVv respectively.Comment: 12 pages, LaTex, no figur

A nonlocal eigenvalue problem and the stability of spikes for reaction-diffusion systems with fractional reaction rates

We consider a nonlocal eigenvalue problem which arises in the study of stability of spike solutions for reaction-diffusion systems with fractional reaction rates such as the Sel'kov model, the Gray-Scott system, the hypercycle Eigen and Schuster, angiogenesis, and the generalized Gierer-Meinhardt system. We give some sufficient and explicit conditions for stability by studying the corresponding nonlocal eigenvalue problem in a new range of parameters