Long-Jye Sheu

Parametric Analysis and Impulsive Synchronization of Fractional-Order Newton-Leipnik Systems

In this paper, the influences of parameters on the dynamics of a fractional-order Newton-Leipnik system were numerically studied. Impulsive synchronization of two fractional-order Newton-Leipnik systems was also investigated. The ranges of the parameters used in this study were relatively broad. The system displayed comprehensive dynamic behaviours, such as fixed points, periodic motion (including periodic-3 motion), chaotic motion, and transient chaos. A period-doubling route to chaos in this study was also found. Sufficient conditions on synchronization of the two systems are provided and illustrative example is given.

Application of advanced process control in plastic injection molding

This research applies Advanced Process Control (APC)-based injection molding system to improve the quality of products. The relationships between the input parameters (injection velocity, injection pressure, injection time and barrel temperature) and a single output variable (the weight of product) were found through an experimental design method. Moreover, the injection molding process model was built via a multiple regression analysis. A dynamic model turning minimum variance (DMTMV) method is utilized to control the process. Quantified improvements were further obtained from experiments.

Hybrid Stability Checking Method for Synchronization of Chaotic Fractional-Order Systems

A hybrid stability checking method is proposed to verify the establishment of synchronization between two hyperchaotic systems. During the design stage of a synchronization scheme for chaotic fractional-order systems, a problem is sometimes encountered. In order to ensure the stability of the error signal between two fractional-order systems, the arguments of all eigenvalues of the Jacobian matrix of the erroneous system should be within a region defined in Matignon’s theorem. Sometimes, the arguments depend on the state variables of the driving system, which makes it difficult to prove the stability. We propose a new and efficient hybrid method to verify the stability in this situation. The passivity-based control scheme for synchronization of two hyperchaotic fractional-order Chen-Lee systems is provided as an example. Theoretical analysis of the proposed method is validated by numerical simulation in time domain and examined in frequency domain via electronic circuits.

Complete synchronization of two Chen-Lee systems

This study demonstrates that complete synchronization of two Chen-Lee chaotic systems can be easily achieved. The upper bound of the Chen-Lee chaotic system is estimated numerically. A controller is designed to synchronize two chaotic systems. Sufficient conditions for synchronization are obtained using Lyapunovs direct method. Two numerical examples are presented to verify the proposed synchronization approach.

IMPULSIVE SYNCHRONIZATION AND ITS IMPLEMENTATION IN CHEN–LEE SYSTEMS

The impulsive synchronization of two chaotic Chen–Lee systems was investigated in this paper. Based on Lyapunovs direct method, sufficient conditions for the global exponential synchronization and global asymptotical synchronization were derived. Further, the theoretical results were verified by a numerical simulation. In addition, the impulsive synchronization of two chaotic Chen–Lee systems was also implemented using an electronic circuit.

A quality control of the injection molding process using EWMA predictor and minimum-variance controller

In this study, EWMA (exponentially weighted moving average) predictor and minimum-variance controller were applied to improve the product quality in the injection molding process. To simplify the process model and reduce the system loads, design of experiments (DOE) technique was adopted to analyze the important factors which have the significant effects on the product quality and their relative correlations. The results of this research not only can steadily control the manufacturing process and reduce the product loss and maintenance time for un-warning malfunction, but can also increase the efficiency of the equipment and the process.

The onset of convection in a viscoelastic nanofluid layer

This paper presents a linear stability analysis for natural convection in a horizontal layer of viscoelastic nanofluid whose rheological behavior is described by an Oldroyd B model. The effects of Brownian motion and thermophoresis on the motion of nanoparticles are considered. The onset criterion for stationary and oscillatory convection is derived analytically. Results indicate that oscillatory instability is possible in both bottom-heavy and top-heavy nanoparticle distributions. Regimes of stationary and oscillatory convection for various parameters are derived and discussed in detail.

Microfluidic mixing using chaotic signals from the Chen-Lee system

A design and analysis of an application to enhance microfluidic mixing through the use of electrodes which are controlled by the chaotic Chen-Lee system and its fractional-order system are presented in this project. At first, a microfluidic mixer with two pairs of electrodes on side walls is built. Varying electric fields are generated using the chaotic signals produced from the Chen-Lee system, resulting in enhancement of micro-scale stirring through stretch-and-fold mechanism. After that, the performance is evaluated by varying the main frequency band of the chaotic signals. Furthermore, the parametric analysis and the use of signal from the fractional-order Chen-Lee system are to be investigated in the mixing application.

Passivity-Based Synchronization of the Hyperchaotic Chen-Lee Systems and Its Electronic Circuit Realization

The chaos synchronization between two hyper chaotic Chen-Lee systems is investigated via passive control theory. Feedback controller is designed by applying the passivity theory. The controller is much simpler than those obtained from other methods. Theoretical analysis of the proposed method is validated by numerical simulation and realized by electronic circuits. The influence of the controller parameter is also provided for enhancing the efficiency of synchronization.