This paper proposes a data-based model-free approach to reference trajectory tracking in two-degree-offreedom (2-DOF) nonlinear control system structures. This model-free control approach tunes both the feedback controller parameters and the reference input sequence accounting for control saturation and control rate constraints. The controller is iteratively tuned in a nonlinear framework that ...

PURPOSE We investigated the temporal variation of the induced magnetic field due to the transverse and the longitudinal gradient coils in tungsten collimators arranged in hexagonal and pentagonal geometries with and without gaps between the collimators. METHODS We modeled x-, y-, and z-gradient coils and different arrangements of single-photon emission computed tomography (SPECT) collimators ...

Selecting a threshold from the gradient histogram, a histogram of gradient magnitudes, of an image plays a crucial role in a gradient based edge detection system. This paper presents a methodology to determine the threshold from a gradient histogram generated using any kind of linear gradient operator on an image. We consider the image as a random process with dependent samples, model the gradi...

Identification of unknown system by training the parameters adaptively using different fuzzy models has been proven an interesting research area over last few decades. The objective of this paper is to identify a standard fuzzy system using different gradient methods and discuss their characteristics. Approach of this work is to calculate the gradient of the appropriate cost function to minimiz...

Sensitivity analysis results are useful both for the early design stage – where the parametric space can be substantially reduced – but also in operating conditions, e.g. of the future electric ship, resulting in reduced operational costs and increased reliability. Here we discuss variance-based methods to analyze the sensitivity of stochastic electro-mechanical systems with multirate dynamics....

Introduction: Spatial signal encoding in MRI is usually performed via B0-gradients. An alternative method is the use of B1-gradients (so-called RF encoding), already suggested in the early days of MR (see, e.g., [1-3]). RF encoding offers the possibility to omit all B0-gradients, which would allow for MR scanning more or less free of acoustic noise. This advantage might be counterbalanced by lo...

The design process and the magnetic measurements 011 a permanent magnet asymmetric dipole to be used for magnetic selection in a Cs beam frequency standard is presented Tbe design target is to create a magnetic induction gradient of 50 Tlm in a zone extending 10 mm in width and 50 mm in length. The computer aided design process is outlined and design predictions are compared with measurements o...

We describe a modified polyacrylamide gel electrophoresis method with which plasma proteins are excellently resolved in 4 h. We made a three-layer discontinuous gradient gel with concentrations of 80,60, and 45 g of polyacrylamide per liter of tris(hydroxymethyl)aminomethane/ethylenediaminetetraacetic acid/borate buffer, pH 9.2. Time and material needed in the preparation of the gel was greatly...