The Experts below are selected from a list of 57705 Experts worldwide ranked by ideXlab platform
Axing Zhu - One of the best experts on this subject based on the ideXlab platform.
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improving the accuracy of landslide susceptibility model using a novel region Partitioning Approach
Landslides, 2018Co-Authors: Haoyuan Hong, Biswajeet Pradhan, Maher Ibrahim Sameen, Bahareh Kalantar, Axing ZhuAbstract:Landslide is a natural disaster that threatens human lives and properties worldwide. Numerous have been conducted on landslide susceptibility mapping (LSM), in which each has attempted to improve the accuracy of final outputs. This study presents a novel region-Partitioning Approach for LSM to understand the effects of Partitioning a focused region into smaller areas on the prediction accuracy of common regression models. Results showed that the Partitioning of the study area into two regions using the proposed method improved the prediction rate from 0.77 to 0.85 when support vector machine was used, and from 0.87 to 0.88 when logistic regression model was utilized. The spatial agreements of the models were also improved after Partitioning the area into two regions based on Shannon entropy equations. Our comparative study indicated that the proposed method outperformed the geographically weighted regression model that considered the spatial variations in landslide samples. Overall, the main advantages of the proposed method are improved accuracy and the reduction of the effects of spatial variations exhibited in landslide-conditioning factors.
Guilin Wen - One of the best experts on this subject based on the ideXlab platform.
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improved stability criteria for time varying delayed t s fuzzy systems via delay Partitioning Approach
Fuzzy Sets and Systems, 2011Co-Authors: Guilin WenAbstract:This paper focuses on the stability analysis for uncertain Takagi-Sugeno (T-S) fuzzy systems with interval time-varying delay. The uncertainties of system parameter matrices are assumed to be time-varying and norm-bounded. Some new Lyapunov-Krasovskii functionals (LKFs) are constructed by nonuniformly dividing the whole delay interval into multiple segments and choosing different Lyapunov functionals to different segments in the LKFs. By employing these LKFs, some new delay-derivative-dependent stability criteria are established for the nominal and uncertain T-S fuzzy systems in a convex way. These stability criteria are derived that depend on both the upper and lower bounds of the time derivative of the delay. By employing the new delay Partitioning Approach, the obtained stability criteria are stated in terms of linear matrix inequality (LMI). They are equivalent or less conservative while involving less decision variables than the existing results. Finally, numerical examples are given to illustrate the effectiveness and reduced conservatism of the proposed results.
Dan Keun Sung - One of the best experts on this subject based on the ideXlab platform.
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delays dependent region Partitioning Approach for stability criterion of linear systems with multiple time varying delays
Automatica, 2018Co-Authors: Won Il Lee, Poogyeon Park, Dan Keun SungAbstract:Abstract This paper considers a delay-dependent stability criterion for linear systems with multiple time-varying delays. To exploit all possible information for the relationships among the marginally delayed states ( x ( t − τ i M ) , x ( t − τ i + 1 M ) ), the exactly delayed states ( x ( t − τ i ( t ) ) , x ( t − τ i + 1 ( t ) ) ), and the current state x ( t ) for each pair ( i , i + 1 ) of time-varying delays, a delays-dependent region Partitioning Approach in double integral terms is proposed. By applying the Wirtinger-based integral inequality and the reciprocally convex Approach to terms resulted from the region Partitioning, a stability criterion is derived in terms of linear matrix inequalities. Numerical examples show that the resulting criterion outperforms the existing one in literature.
James Lam - One of the best experts on this subject based on the ideXlab platform.
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a frequency Partitioning Approach to stability analysis of two dimensional discrete systems
Multidimensional Systems and Signal Processing, 2015Co-Authors: James Lam, Huijun GaoAbstract:Although there exist necessary and sufficient conditions for two-dimensional (2-D) discrete systems, their application scope is almost limited to system analysis only and no work has demonstrated their possible extension to system synthesis. In this paper, we propose a novel frequency-Partitioning Approach to analyzing stability of 2-D discrete state-space systems. A piecewise constant matrix function is introduced to approximate the solution to the frequency-dependent Lyapunov inequality, whose solvability is known to be equivalent to stability of a 2-D state-space model. Then by the generalized Kalman---Yakubovich---Popov Lemma, new stability conditions are derived for the Roesser model and the Fornasini---Marchesini (FM) first and second models, respectively. Stability criteria in the paper simultaneously overcome the drawbacks of the simple 2-D Lyapunov inequality Approach and the existing necessary and sufficient conditions: (1) They are expressed in terms of linear matrix inequalities (LMIs), which are generally less conservative than the existing simple 2-D Lyapunov inequality-based results, and could be improved by increasing the Partitioning number; (2) Since each of the LMIs corresponds to a simple 2-D Lyapunov inequality, they are more suitable for further development for system synthesis than the existing necessary and sufficient conditions, which is demonstrated by an illustrative application to state-feedback control of an uncertain FM second model.
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stability and stabilization of delayed t s fuzzy systems a delay Partitioning Approach
IEEE Transactions on Fuzzy Systems, 2009Co-Authors: Yan Zhao, Huijun Gao, James LamAbstract:This paper proposes a new Approach, namely, the delay Partitioning Approach, to solving the problems of stability analysis and stabilization for continuous time-delay Takagi-Sugeno fuzzy systems. Based on the idea of delay fractioning, a new method is proposed for the delay-dependent stability analysis of fuzzy time-delay systems. Due to the instrumental idea of delay Partitioning, the proposed stability condition is much less conservative than most of the existing results. The conservatism reduction becomes more obvious with the Partitioning getting thinner. Based on this, the problem of stabilization via the so-called parallel distributed compensation scheme is also solved. Both the stability and stabilization results are further extended to time-delay fuzzy systems with time-varying parameter uncertainties. All the results are formulated in the form of linear matrix inequalities (LMIs), which can be readily solved via standard numerical software. The advantage of the results proposed in this paper lies in their reduced conservatism, as shown via detailed illustrative examples. The idea of delay Partitioning is well demonstrated to be efficient for conservatism reduction and could be extended to solving other problems related to fuzzy delay systems.
Kit Po Wong - One of the best experts on this subject based on the ideXlab platform.
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adaptive Partitioning Approach to self sustained smart grid
Iet Generation Transmission & Distribution, 2017Co-Authors: Youwei Jia, Chun Sing Lai, Songjian Chai, Kit Po WongAbstract:Effective network Partitioning becomes an essential step to realise self-sustained smart grid, which serves as a prerequisite for ‘self-healing’ enabled decentralised control. Splitting the power network (PN) into areas is the last resort to avoid the spread of disruption and to maintain as many network survivals as possible. This study aims to resolve the issue of multi-objective PN Partitioning by deploying a newly proposed hybrid Approach concerning both real power balance and voltage profile. The proposed Approach combines the Laplacian spectrum and self-organising map, which adaptively attains self-sustained network partitions on different operating conditions. The resultant partitions are characterised by the minimal intra-area real power imbalance with a healthy voltage profile. The authors experimentally evaluate the Partitioning effectiveness and computational efficiency in several case studies including on the New England 39-bus, IEEE 118-bus, and Polish 2383-bus transmission systems.
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SMC - A Novel Network Partitioning Approach in Smart Grid Environment
2015 IEEE International Conference on Systems Man and Cybernetics, 2015Co-Authors: Youwei Jia, Loi Lei Lai, Kit Po WongAbstract:Smart grid development highlights the "self-healing" capability as it enables a power system to efficiently and automatically react to disturbances and guide the system to the best possible state. Effectively Partitioning the power network (PN) into suitable areas or zones to accommodate subsequent control actions is useful. In this paper, a novel Partitioning Approach that combines Laplacian spectrum of a PN and self organizing map (SOM) algorithm is proposed. This Approach aims to optimize the Partitioning solution so as to minimize the real power imbalance and simultaneously maintain a satisfactory voltage profile. Case study is carried out on New England 39-bus system, which demonstrates the effectiveness of the proposed Approach.
