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Application of the recurrent multilayer perceptron in modelingcomplex process dynamics 总被引:1,自引:0,他引:1
A nonlinear dynamic model is developed for a process system, namely a heat exchanger, using the recurrent multilayer perceptron network as the underlying model structure. The perceptron is a dynamic neural network, which appears effective in the input-output modeling of complex process systems. Dynamic gradient descent learning is used to train the recurrent multilayer perceptron, resulting in an order of magnitude improvement in convergence speed over a static learning algorithm used to train the same network. In developing the empirical process model the effects of actuator, process, and sensor noise on the training and testing sets are investigated. Learning and prediction both appear very effective, despite the presence of training and testing set noise, respectively. The recurrent multilayer perceptron appears to learn the deterministic part of a stochastic training set, and it predicts approximately a moving average response of various testing sets. Extensive model validation studies with signals that are encountered in the operation of the process system modeled, that is steps and ramps, indicate that the empirical model can substantially generalize operational transients, including accurate prediction of instabilities not in the training set. However, the accuracy of the model beyond these operational transients has not been investigated. Furthermore, online learning is necessary during some transients and for tracking slowly varying process dynamics. Neural networks based empirical models in some cases appear to provide a serious alternative to first principles models. 相似文献
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Mobile robots can be used in many applications, such as exploration, search and rescue, reconnaissance, security, and cleaning.
Mobile robots usually carry batteries as their energy source and their operational time is restricted by the finite energy
available from the batteries. Therefore, energy constraints are critical to the service time of mobile robots. This paper
investigates the minimum-energy control problem for translational trajectory generation, which minimizes the energy drawn
from the batteries. Optimal control theory is used to find the optimal velocity trajectory in analytic form. To demonstrate
energy efficiency obtainable, we performed simulations of minimum-energy velocity control and compared the results with loss-minimization
control and energy-optimal trapezoidal velocity profiles. Simulation results showed that significant energy savings can be
achieved, of up to 9% compared with loss-minimization control and up to 10% compared with energy-optimal trapezoidal velocity
profile. We also performed an actual robot experiment using Pioneer 3-AT platform to show the validity of the proposed minimum-energy
velocity control. The experimental results revealed that the proposed minimum-energy velocity control can save the battery
energy up to 10% compared with loss-minimization control.
Categories (3): Robot control, (5): RobotMotion Planning 相似文献
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Jong Min Kim Donghee Lee Sang Lyul Min Chong Sang Kim 《Information Processing Letters》2003,85(2):93-97
A new dynamic buffer allocation strategy based on the notion of marginal gains is presented for the buffer cache that is used by the operating system to store frequently accessed disk blocks in main memory, and the performance of the proposed strategy is compared with those of previous allocation strategies. In the proposed strategy, marginal gain values are predicted by exploiting functions that approximate the expected number of buffer hits per unit time. Experimental results from both trace-driven simulation and an actual implementation in the FreeBSD operating system show that the proposed strategy accurately predicts the marginal gain values for various workloads resulting in significantly improved buffer hit ratios. 相似文献
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In this paper, we propose an efficient design method for area optimization in a digital filter. The conventional methods to reduce the number of adders in a filter have the problem of a long critical path delay caused by the deep logic depth of the filter due to adder sharing. Furthermore, there is such a disadvantage that they use the transposed direct form (TDF) filter which needs more registers than those of the direct form (DF) filter. In this paper, we present a hybrid structure of a TDF and DF based on the flattened coefficients method so that it can reduce the number of flip‐flops and full‐adders without additional critical path delay. We also propose a resource sharing method and sharing‐pattern searching algorithm to reduce the number of adders without deepening the logic depth. Simulation results show that the proposed structure can save the number of adders and registers by 22 and 26%, respectively, compared to the best one used in the past. 相似文献
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Munhyoung Cho Chong Hyun Lee Soohong Kim Joohwan Chun 《AEUE-International Journal of Electronics and Communications》2004,58(4):299-301
In this paper, we propose a new robust code division multiple access (CDMA) receiver of which weight vector is obtained by projecting the effective spatio-temporal signature waveform onto the signal subspace of the data covariance matrix. We verified our proposed algorithm by the field measured data obtained with a custom-built wideband CDMA test-bed. It will be shown that the proposed algorithm is robust to the signal mismatch. 相似文献
20.
H.W. Wan T.C. Chong S.J. Chua 《Photonics Technology Letters, IEEE》1991,3(8):730-732
It is shown that In/sub 1-x/Ga/sub x/As/In/sub 0.52/Al/sub 0.48/As MQW structures with the wells under tensile strain obtained by the appropriate selection of the Ga mole fraction and well size can achieve polarization-insensitive optical switching and modulation for a wide range of wavelengths between 1.0 and 1.6 mu m. For example, a change in refractive index of -0.5% at about 1.55 mu m will facilitate an intersectional angle of more than 10 degrees in a total internal reflection switch which can be readily fabricated. Hence, this material system is promising for long-wavelength polarization-insensitive semiconductor optoelectronic devices.<> 相似文献