We have investigated the bifurcation structure of the transmitted power for an electrooptic bistable device with a delayed feedback. When the bifurcation parameter (the input power) is very slowly increased we observe...
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ISBN:
(纸本)3540175504
We have investigated the bifurcation structure of the transmitted power for an electrooptic bistable device with a delayed feedback. When the bifurcation parameter (the input power) is very slowly increased we observe bifurcations and chaotic behaviour according to the period doubling scheme of Feigenbaum. For a time-dependent input power, however, we observe a new bifurcation scheme with hysteresis in the bifurcation points, so different values of the bifurcation points are observed when the input power is increasing and decreasing. The hysteresis phenomenon is furthermore investigated from a numerical simulation. We find that one crucial effect of the time-dependent input power is that it induces a dynamical stabilization on solutions which are unstable in steady-state.
Multi-mode embedded real-time systems exhibit a specific behaviour for each mode, and upon a mode-change request the task-set and timing interfaces of the system need to be changed. This paper presents the implementat...
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Multi-mode embedded real-time systems exhibit a specific behaviour for each mode, and upon a mode-change request the task-set and timing interfaces of the system need to be changed. This paper presents the implementation of a MultiMode Adaptive Hierarchical Scheduling Framework (MMAHSF) and provides a generic skeleton (framework) for a two-level adaptive hierarchical scheduling supporting multiple modes and multiple mode-change mechanisms on an open source real-time operating system (FreeRTOS). The MMAHSF enable application-specific implementations of mode-change protocols using a set of predefined mode-change mechanisms. The paper addresses different mode-change mechanisms at both global and local scheduling levels. It presents examples of mode-change protocols that are developed by composing together these mechanisms in multiple ways and provide the initial results of executing these protocols in the MMAHSF implementation on an AVR 32-bit board EVK1100.
Human face detection plays an important role in many applications such as video surveillance, face recognition, and face image database management. This paper describes a fast face detection algorithm with accurate re...
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ISBN:
(纸本)9781424403660
Human face detection plays an important role in many applications such as video surveillance, face recognition, and face image database management. This paper describes a fast face detection algorithm with accurate results. We use lighting compensation to improve the performance of color-based scheme, and reduce the computation complexity of feature-based scheme. Our method is effective on facial variations such as dark/bright vision, close eyes, open moth, a half-profile face. and pseudo faces. It is worth stressing that our algorithm can also discriminate cartoon and human face correctly. The experimental results show that our approach can detect a frame in 111 msecs with the 92.3% detection rate.
An overview is given on the application of the generalized variable structure control to a manipulator arm. Experimental study made on a manipulator arm of three degrees of freedom, each being piloted by an electrical...
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ISBN:
(纸本)0780359577
An overview is given on the application of the generalized variable structure control to a manipulator arm. Experimental study made on a manipulator arm of three degrees of freedom, each being piloted by an electrical actuator, is discussed.
A two-dimensional infinite length porous slab is employed to simulate biomimetic porous scaffold. The pores of slab are saturated with a relatively low and high viscous fluids such as air and bone marrow. Ultrasonic w...
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ISBN:
(纸本)9780791885543
A two-dimensional infinite length porous slab is employed to simulate biomimetic porous scaffold. The pores of slab are saturated with a relatively low and high viscous fluids such as air and bone marrow. Ultrasonic waves based on the Biot-JKD formulation travel through the porous slab and create viscous exchanges between the skeletal frame and the fluid. The Biot-JKD formulation focuses on the parameters, biomarkers of the biomimetic porous scaffold, which are sensitive to the transmission and reflection signals. These parameters include porosity, tortuosity, viscous characteristic length, Young's modulus, and Poisson's ratio. An artificial neural network (ANN) based on a set of the biomarkers is rendered to model the transmitted and reflected waves from the porous slab. The validation of the proposed analytical approach and released artificial neural network is evaluated by the pertinent literature. The output of the artificial neural network, the transmitted-reflected waves, is inversely applied to the analytical expression to estimate the biomarkers associated with bone regeneration. The results show that for a medium filled with a relatively high viscous fluid the longitudinal waves are more prone to estimate mechanical properties of the medium such as Young's modulus and Poisson's ratio while the transverse waves, in addition to longitudinal waves, are essential to estimate the physical properties of the medium including porosity, tortuosity, and viscous characteristic length. Furthermore, it is also concluded that for the medium filled with a relatively low viscous fluid such as air the longitudinal waves alone is able to estimate the biomarkers, which reduce significantly the computational efforts.
Seismic attributes allow us to extract valuable information from the seismic amplitude cube, thus making a more complete and accurate interpretation. In this paper, we use spectral-decomposition analysis, curvature an...
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Cataract is one of the most common ocular diseases. It causes cloudy vision and vision loss in a vast number. In this paper, a convolutional neural network model has been proposed to detect cataract in the eyes. This ...
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