The national mangrove rehabilitation required mangrove spatial information with very high accuracy. This study successfully developed the classification algorithm measurable for mapping mangrove forest change based on...
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The national mangrove rehabilitation required mangrove spatial information with very high accuracy. This study successfully developed the classification algorithm measurable for mapping mangrove forest change based on machine learning. We also modified the recursive feature elimination (RFE) method to obtain the most optimal feature importance (FI). The results showed that the developed classification algorithm was built based on the five most important features including digital elevation model (DEM), near-infrared (NIR), normalized difference moisture index (NDMI), normalized difference water index (NDWI), and distances from brackish water river (DBWR). The developed algorithm increased overall and kappa accuracy by 0.48% and 0.01, respectively.
An adaptive multivariable continuous non-singular terminal sliding mode (NTSM) control scheme with fast and robust input shaper (FRIS) is developed for flexible spacecraft which is subject to external disturbances. Fi...
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An adaptive multivariable continuous non-singular terminal sliding mode (NTSM) control scheme with fast and robust input shaper (FRIS) is developed for flexible spacecraft which is subject to external disturbances. Firstly, the FRIS is proposed to suppress residual vibration of flexible spacecraft. It is shown that the FRIS decreases the duration of the impulse sequence at the meanwhile it is robust to parameter uncertainties. Then the adaptive multivariable continuous NTSM control is proposed to the attitude tracking of flexible spacecraft and the supression of residual vibration in finite time. The remarkable feature of the developed algorithm is to eliminate the overestimation of the control gains, and the tracking errors can be driven into a small region around zero in finite time even in the presence of bounded but unknown disturbances. Finally, some numerical simulations are performed to validate the efficiency of the developed algorithm.
Lots of prior models for natural image wavelet coefficients have been proposed in the last two decades. Although most of them belong to the Scale Mixture of Gaussian (GSM) models, they are of obviously different analy...
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Lots of prior models for natural image wavelet coefficients have been proposed in the last two decades. Although most of them belong to the Scale Mixture of Gaussian (GSM) models, they are of obviously different analytical forms. As a result, Bayesian image denoising algorithms based on these prior models are also very different from each other. In this paper, we develop a novel image denoising algorithm by combining the Expectation Maximization (EM) scheme and the properties of the GSM models. The developed algorithm is of a simple iterative form and can converge quickly. It only uses the derivative information of a probability density function and is suitable for all GSM-type prior models that have an analytical probability density function. The developed algorithm can be viewed as a unified Bayesian image denoising framework. As examples, several classical and recently-proposed prior models for natural image wavelet coefficients are tested and some new results are obtained. (c) 2008 Optical Society of America.
A dissipating energy-based technique is proposed to locate the source of forced oscillations (FOs) in power systems. The network and load information is incorporated into the developed algorithm and continuously updat...
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A dissipating energy-based technique is proposed to locate the source of forced oscillations (FOs) in power systems. The network and load information is incorporated into the developed algorithm and continuously updated using supervisory control and data acquisition (SCADA) measurement. The effect of electromechanical damping on system response in FO scenario is discussed;and therefore, the efficiency of the proposed technique to locate the source has been investigated. The proposed methodology is tested and verified for different simulation test cases and for different scenario viz. for single and multiple sources of disturbances. In the case of multiple sources of disturbances with different time of initiation of the disturbance, the proposed technique successfully locates all sources in their time durations of disturbance. Different load models have been evaluated for their impact on the success of the proposed algorithm in a real-time digital simulation environment. The proposed technique is successfully verified for the test cases reported by the IEEE PES Task Force on Oscillation Source Location.
The context of this study is the rough machining of pockets using Contour-Parallel Offset (CPO) trajectories. This requires either minimizing the toolpath or increasing the feed rate because the objective during the r...
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The context of this study is the rough machining of pockets using Contour-Parallel Offset (CPO) trajectories. This requires either minimizing the toolpath or increasing the feed rate because the objective during the roughing stage is to minimize machining time. Increasing the spacing between contours to a value close to the tool diameter minimizes the total toolpath length. However, this can result in material leftover between passes in the corners. A lot of work has been done to eliminate uncut areas after machining. Rounded loops added to the continuous CPOs proposed by several researchers and integrated into the CAM software (Mastercam) provide the most reliable solution that can maintain the feed rate at its maximum value during direction changes. However, the size of these loops penalizes the gain already achieved by maintaining the feed rate. Therefore, it is evident to conduct a detailed study to make the latter more optimized. In this paper, we propose a generalized algorithm for any polygon. It utilizes new formulas and adds an optimized loop at any point where uncut areas appear. This loop challenges the best existing methods aimed at minimizing machining time during rough pocket machining with CPO toolpaths, as it is designed in a highly optimized manner and ensures overlap in the corners between passes in any situation. For the validation of this new method, comparisons were made with the best methods found in the literature through simulations. Additionally, several tests conducted within Mastercam and with other methods, as well as a real implementation, have confirmed the effectiveness and advantage of the proposed method compared to the best existing rough pocket machining methods. The fact that this method offers a highly optimized toolpath and maintains the actual feed rate at its maximum due to the rounded profile of the loop suggests that rough pocket machining with CPO toolpaths could become the best solution.
This paper proposes an optimal control algorithm for a polynomial system with a quadratic criterion over infinite horizon. The designed regulator gives a closed form solution to the infinite horizon optimal control pr...
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ISBN:
(纸本)9781479901777
This paper proposes an optimal control algorithm for a polynomial system with a quadratic criterion over infinite horizon. The designed regulator gives a closed form solution to the infinite horizon optimal control problem for a polynomial system with a quadratic criterion. The obtained solution consists in a feedback control law obtained by solving a Riccati algebraic equation dependent on the state. Numerical simulations in the example show advantages of the developed algorithm.
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