The article discusses the use of multicore processors and parallel architectures to improve data structures. It argues that a major shift is underway, as of March 2011, in the properties of concurrent data structures ...
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The article discusses the use of multicore processors and parallel architectures to improve data structures. It argues that a major shift is underway, as of March 2011, in the properties of concurrent data structures and their implementing algorithms. This is expected to cause data structures such as stacks, queues, and heaps to become obsolete, replaced by looser constructs involving randomization and distribution. Software engineers are advised to familiarize themselves with the performance benefits and limitations this involves.
Electrostatic microactuators are used extensively in MEMS sensors, RF switches and microfluidic pumps. The high bandwidth operation required by these applications complicates the implementation of feedback controllers...
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Electrostatic microactuators are used extensively in MEMS sensors, RF switches and microfluidic pumps. The high bandwidth operation required by these applications complicates the implementation of feedback controllers. This paper designs, proves stability and simulates a feedforward repetitive controller for an electrostatic microbridge. High residual stress creates tension in the microbridge that dominates bending stiffness so a pinned string model with uniform electrostatic force loading is used for model-based control. The control objective is to force the microbridge displacement to follow prescribed spatial and periodic time trajectories. Viscous damping ensures boundedness of the distributed transverse displacement in response to bounded inputs. The average displacement is measured by capacitive sensing and processed offline using a repetitive control algorithm that updates a high speed waveform generator's parameters. Simulations show that the performance depends on the amount of damping. With less than 1% damping in a representative microbridge structure, repetitive control reduces the midspan displacement overshoot by 83%.
We develop a formal system for describing cyclograms in interval temporal logic. We show that it can be applied for modeling and verification (testing correctness) of cyclogram models (CM). We describe how a rule-base...
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We develop a formal system for describing cyclograms in interval temporal logic. We show that it can be applied for modeling and verification (testing correctness) of cyclogram models (CM). We describe how a rule-based knowledge base of a CM and instruments for constructing algorithms that output discrete controlling influences can be used to improve testing quality.
Part II. Proposes the usage of symbolic learning methods based on multiple-valued logic and implemented in reconfigurable computer hardware. Aspects of realizing cube calculus operations in hardware; Types of cube ope...
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Part II. Proposes the usage of symbolic learning methods based on multiple-valued logic and implemented in reconfigurable computer hardware. Aspects of realizing cube calculus operations in hardware; Types of cube operations; Classes of computation patterns of cube operations.
This paper investigates the effect of unintended high frequency excitations generated by the semi-active sky-hook control algorithm on the isolation properties of a car suspension. Using a quarter car model, an energy...
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This paper investigates the effect of unintended high frequency excitations generated by the semi-active sky-hook control algorithm on the isolation properties of a car suspension. Using a quarter car model, an energy transfer from low to high frequency is established. An alternative algorithm is presented in this paper, in order to achieve smooth variations of the control force. Compared with the continuous semi-active sky-hook, the algorithm has been found to provide a similar damping of the body resonance, but also a better isolation at high frequency and global comfort. (C) 2010 Elsevier Ltd. All rights reserved.
Based on the fixed point concept in functional analysis, an improvement on the traditional spectral method is proposed for nonlinear oscillation equations with periodic solution. The key idea of this new approach ( na...
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Based on the fixed point concept in functional analysis, an improvement on the traditional spectral method is proposed for nonlinear oscillation equations with periodic solution. The key idea of this new approach ( namely, the spectral fixed point method, SFPM) is to construct a contractive map to replace the nonlinear oscillation equation into a series of linear oscillation equations. Usually the series of linear oscillation equations can be solved relatively easily. Different from other existing numerical methods, such as the well-known Runge-Kutta method, SFPM can directly obtain the Fourier series solution of the nonlinear oscillation without resorting to the Fast Fourier Transform (FFT) algorithm. In the meanwhile, the steepest descent seeking algorithm is proposed in the framework of SFPM to improve the computational efficiency. Finally, some typical cases are investigated by SFPM and the comparison with the Runge-Kutta method shows that the present method is of high accuracy and efficiency.
Graphite carbon foam, a mesophase, pitch-based material, portrays highly ordered topology structures which exhibit superior mechanical and thermal properties. Typical graphite carbon foam with dimensions 5 cm(3), can ...
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Graphite carbon foam, a mesophase, pitch-based material, portrays highly ordered topology structures which exhibit superior mechanical and thermal properties. Typical graphite carbon foam with dimensions 5 cm(3), can have a surface area greater than 11 m(2), making it an excellent candidate for heat transfer applications. Accurate three dimensional modeling of carbon foams is necessary to study and predict their properties in simulation. This paper describes a computer algorithm for modeling POCO Foam (R) and similar carbon foams. The algorithm, written in MATLAB, captures the principle physical parameters of the carbon foam including bubble and pore diameter ranges and overall foam void percentage while retaining the random dispersal of spherical bubbles found in manufactured foams. (C) 2010 Elsevier Ltd. All rights reserved.
What does computation sound like, and how can computational processing be integrated into live-coding practice along with code? This article gives insights into three years of artistic research and performance practic...
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What does computation sound like, and how can computational processing be integrated into live-coding practice along with code? This article gives insights into three years of artistic research and performance practice with Betablocker, an imaginary central processing unit architecture, specifically designed and implemented for live-coding purposes. It covers the themes of algorithmic composition, sound generation, genetic programming, and autonomous coding in the light of self-manipulating code and artistic research practice.
A robust online fault prediction method which combines sliding autoregressive moving average (ARMA) modeling with online least squares support vector regression (LS-SVR) compensation is presented for unknown nonlinear...
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A robust online fault prediction method which combines sliding autoregressive moving average (ARMA) modeling with online least squares support vector regression (LS-SVR) compensation is presented for unknown nonlinear system. At first, we design an online LS-SVR algorithm for nonlinear time series prediction. Based on this, a combined time series prediction method is developed for nonlinear system prediction. The sliding ARMA model is used to approximate the nonlinear time series;meanwhile, the online LS-SVR is added to compensate for the nonlinear modeling error with external disturbance. As a result, the one-step-ahead prediction of the nonlinear time series is achieved and it can be extended to n-step-ahead prediction. The result of the n-step-ahead prediction is then used to judge the fault based on an abnormity estimation algorithm only using normal data of system. Accordingly, the online fault prediction is implemented with less amount of calculation. Finally, the proposed method is applied to fault prediction of model-unknown fighter F-16. The experimental results show that the method can predict the fault of nonlinear system not only accurately but also quickly.
The storage energy of high frequency reactive component for the switched mode power converter is a new factor to assess the performance. The instability of the switched-mode converter under the peak current control mo...
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The storage energy of high frequency reactive component for the switched mode power converter is a new factor to assess the performance. The instability of the switched-mode converter under the peak current control mode is examined for its storage energy. Bifurcation and chaos of the storage energy in the inductor and capacitor are observed based on the stroboscopic map. The boundary of maximum storage energy is given to be an alternative to study the instability of the system in this study. Zero energy is obtained in stable period 1 and the storage energy with the same value and opposite direction is obtained in period 2. The simulation results of bifurcation and chaos of energy are obtained under different parameters and verified by experiment. The boundary of instability of energy stored in the reactive component under various parameters is formulated and a single equation can be used to indicate the factors. These results can provide a new guideline to design a stable system and provide a new control algorithm for power electronic system.
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