RESUMEN
This brief further explores the problem of finite-time synchronization of delayed recurrent neural networks with the mismatched parameters and neuron activation functions. An improved sliding mode control approach is presented for addressing the finite-time synchronization problem. First, by employing the drive-response concept and the synchronization error of drive-response systems, a novel integral sliding mode surface is constructed such that the synchronization error can converge to zero in finite time along the constructed integral sliding mode surface. Second, a suitable sliding mode controller is designed by relying on Lyapunov stability theory such that all system state trajectories can be driven onto the predefined sliding mode surface in finite time. Moreover, it is found that the presented control approach can be conveniently verified and does not need to solve any linear matrix inequality (LMI) to guarantee the finite-time synchronization of delayed recurrent neural networks. Finally, three numerical examples are exploited to demonstrate the effectiveness of the presented control approach.
RESUMEN
A 46-year-old man presented with large bilateral aneurysm of the axillary arteries combined with Marfan syndrome. Treatment consisted of axillary aneurysm resection and vessel replacement. Postoperative computed tomographic angiography confirmed good flow in the bilateral axillary artery, and the patient recovered without complication.
Asunto(s)
Aneurisma/diagnóstico , Aneurisma/etiología , Arteria Axilar , Síndrome de Marfan/complicaciones , Aneurisma/cirugía , Angiografía , Enfermedades de la Aorta/diagnóstico por imagen , Arteria Axilar/diagnóstico por imagen , Prótesis Vascular , Ecocardiografía , Humanos , Masculino , Síndrome de Marfan/genética , Persona de Mediana Edad , Seno Aórtico/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
A high-frequency ultrasonic transducer for copper or gold wire bonding has been designed, analyzed, prototyped and tested. Modeling techniques were used in the design phase and a practical design procedure was established and used. The transducer was decomposed into its elementary components. For each component, an initial design was obtained with simulations using a finite elements model (FEM). Simulated ultrasonic modules were built and characterized experimentally through the Laser Doppler Vibrometer (LDV) and electrical resonance spectra. Compared with experimental data, the FEM could be iteratively adjusted and updated. Having achieved a remarkably highly-predictive FEM of the whole transducer, the design parameters could be tuned for the desired applications, then the transducer is fixed on the wire bonder with a complete holder clamping was calculated by the FEM. The approach to mount ultrasonic transducers on wire bonding machines also is of major importance for wire bonding in modern electronic packaging. The presented method can lead to obtaining a nearly complete decoupling clamper design of the transducer to the wire bonder.
