Signal inhomogeneity in MRI can influence significantly automatic data processing like segmentation, etc. or even affect the diagnostic procedure. In this work, a new method of intensity nonuniformity correction is pr...
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ISBN:
(纸本)9781538693865;9781538693858
Signal inhomogeneity in MRI can influence significantly automatic data processing like segmentation, etc. or even affect the diagnostic procedure. In this work, a new method of intensity nonuniformity correction is presented. Our idea was to replace FCM clustering by k-harmonic means in the method that uses a standard N3 correction procedure. The algorithm was tested with MRI dataset acquired from a phantom object using a breast MRI coil to simulate real conditions during the study. Results were compared with five other methods using two indexes-integral uniformity and standard deviation of the signal inside the object. For the presented and improved method, the lowest integral uniformity and the reasonable low signal deviation were obtained.
In the paper properties of adaptive feedforward active noise controlsystems with adaptation based on LMS algorithm are discussed from the point of view of initialization of adaptation. A focus on average rate of conv...
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In the paper properties of adaptive feedforward active noise controlsystems with adaptation based on LMS algorithm are discussed from the point of view of initialization of adaptation. A focus on average rate of convergence of the corresponding active noise control algorithms is given. The ideas presented are illustrated by simulation examples in which mixed spectrum and wide-band noises are attenuated.
There exists a vast amount of literature how dissipativity properties can be exploited to design controllers for stability and performance guarantees for the closed loop. With the rising availability of data, there ha...
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ISBN:
(数字)9781728174471
ISBN:
(纸本)9781728174488
There exists a vast amount of literature how dissipativity properties can be exploited to design controllers for stability and performance guarantees for the closed loop. With the rising availability of data, there has therefore been an increasing interest in determining dissipativity properties from data as a means for data-driven systems analysis and control with rigorous guarantees. Most existing approaches, however, consider dissipativity properties that hold only over a finite horizon and mostly only qualitative statements can be made in the presence of noisy data. In this work, we present a novel approach to determine dissipativity of linear time-invariant systems from data where we inherently consider properties that hold over the infinite horizon. Furthermore, we develop a method to verify dissipativity from noisy data with guaranteed robustness.
The goal of this article is to study fundamental mechanisms behind so-called indirect and direct data-driven control for unknown systems. Specifically, we consider policy iteration applied to the linear quadratic regu...
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This article proposes a model that combines the issues related to autonomous vehicles into seven groups. The groups are included in mutual iterations between the user, the autonomous vehicle and the environment. They ...
This article proposes a model that combines the issues related to autonomous vehicles into seven groups. The groups are included in mutual iterations between the user, the autonomous vehicle and the environment. They are: vehicle automation, environmental sensors, automatic perception of the environment based on the processing of vision signals, communication with external devices, interaction with the user, direct transmission of signals to the environment, and future development plans. Bearing in mind the proposed model, various latest solutions presented in the state-of-the-art literature or already offered in vehicles are collected and described.
In this article, an automatic recognition system, of objects that threaten the safety of vehicle users is proposed. These objects are detected in front of the vehicle’s windshield based on images from video recorders...
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ISBN:
(数字)9788362065486
ISBN:
(纸本)9798350373806
In this article, an automatic recognition system, of objects that threaten the safety of vehicle users is proposed. These objects are detected in front of the vehicle’s windshield based on images from video recorders and then classified. The tests were conducted using artificial neural networks on a specially prepared database of frames from real recordings. Recognized objects include: car wheels, car parts, birds, stones and ice. They were recognized in single- and multi-class detections for various parameters of the network model. Detection efficiency of $95 \%$ was achieved in the best case.
This paper analyses P-type iterative learning control algorithm for both linear time invariant systems and a class of nonlinear systems. The convergence conditions of the learning control algorithm are given and prove...
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This paper analyses P-type iterative learning control algorithm for both linear time invariant systems and a class of nonlinear systems. The convergence conditions of the learning control algorithm are given and proved. The result shows that the convergence of the P-type iterative learning control algorithm mainly relies on the choice of learning gain.
In this paper, three error compensation methods are devised to reduce the alignment errors induced by lever arm, body flexure, and measurement time delay respectively. A linear error model based on velocity and attitu...
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This paper investigates the problem of controlling nonlinear dynamical systems subject to state and input constraints while minimizing time-varying and a priori unknown cost functions. We propose a modular approach th...
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As the speed of industrial pick and place robots continues to increase, new trajectory planning strategies will need to be developed in order to optimise the dynamic characteristics of high speed motion. The use of el...
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ISBN:
(纸本)9781424427277
As the speed of industrial pick and place robots continues to increase, new trajectory planning strategies will need to be developed in order to optimise the dynamic characteristics of high speed motion. The use of elliptical pick and place cycles coupled with a Modified Sine cam motion profile is proposed and compared to the traditional rectangular cycle with trapezoidal velocity profile. The elliptical cycle exhibits very smooth, continuous motion curves. Asymmetric acceleration can optionally be specified to reduce peak joint torques and increase maximum pick and place speed.
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