Stability-preserving model order reduction for nonlinear time delay systems

Delay elements are needed to model physical, industrial and engineering systems as action and reaction always come with latency. In this paper, we present an algorithm to obtain the reduced-order models (ROMs) while preserving the stability of nonlinear time delay systems (TDSs), which are approximated first by the piecewise-linear TDSs. One contribution is the derivation of the input-output stability of piecewise-linear TDSs, for the first time. The other is the preservation of the input-output stability of the ROMs. The system matrices are obtained by the left projection matrix from the solution of linear matrix inequalities (LMIs) for the input-output stability test of the original piecewise-linear TDSs and the right projection matrix from matching the estimated moments. An application example then verifies the effectiveness of the proposed method.published_or_final_versio

BlueEyes: assistive technology for visually impaired and blind people - a bluetooth

This report is presented to draw one solution “people to people” (P2P) through the mobile technology that promotes the change in the field of sustainability in relation to the Application system. The HCI interaction field, as the basis for the study of this project, is defined as a multidisciplinary field of knowledge, focusing on the design of computer technology and, in particular, on the interaction between humans and computers. For the development of this project it was necessary enough research information on the technologies that will be needed to create an application mobile. All this research and design belongs to just one of the various stages of this project that has the base of operations at ESEC

Efficient matrix exponential method based on extended Krylov subspace for transient simulation of large-scale linear circuits

Paper 3C-3Matrix exponential (MEXP) method has been demonstrated to be a competitive candidate for transient simulation of very large-scale integrated circuits. Nevertheless, the performance of MEXP based on ordinary Krylov subspace is unsatisfactory for stiff circuits, wherein the underlying Arnoldi process tends to oversample the high magnitude part of the system spectrum while undersampling the low magnitude part that is important to the final accuracy. In this work we explore the use of extended Krylov subspace to generate more accurate and efficient approximation for MEXP. We also develop a formulation that allows unequal positive and negative dimensions in the generated Krylov subspace for better performance. Numerical results demonstrate the efficacy of the proposed method. © 2014 IEEE.published_or_final_versio

Balanced truncation for time-delay systems via approximate gramians

In circuit simulation, when a large RLC network is connected with delay elements, such as transmission lines, the resulting system is a time-delay system (TDS). This paper presents a new model order reduction (MOR) scheme for TDSs with state time delays. It is the first time to reduce a TDS using balanced truncation. The Lyapunov-type equations for TDSs are derived, and an analysis of their computational complexity is presented. To reduce the computational cost, we approximate the controllability and observability Gramians in the frequency domain. The reduced-order models (ROMs) are then obtained by balancing and truncating the approximate Gramians. Numerical examples are presented to verify the accuracy and efficiency of the proposed algorithm. ©2011 IEEE.published_or_final_versionThe 16th Asia and South Pacific Design Automation Conference (ASP-DAC 2011), Yokohama, Japan, 25-28 January 2011. In Proceedings of the 16th ASP-DAC, 2011, p. 55-60, paper 1C-

Clustering based 3D level set method for volumetric cardiac segmentation

Sect.D Computer modeling and simulations : D-5Multi-slice CT (MSCT) provides dynamic three-dimensional (3D) volumetric data of the whole heart, and is an important medical imaging tool for diagnosis of cardiac diseases. Due to the large size of the dynamic data, manual identification, segmentation and tracking of various parts of the heart will be very labor intensive and inefficient. Alternatively, sophisticated image processing techniques, which require minimal user intervention, can be developed and employed to automate such tasks. In this work, we propose a semi-automatic clustering based 3D level set method to robustly segment the endocardium surface from cardiac MSCT images. The theory of level set defines a flexible and powerful surface which is capable of capturing the complex endocardium anatomical structure. A novel speed function for the level set method using a clustering algorithm is proposed to exploit the non-homogeneous blood pool intensity property by supporting a set of independent intensity samples. To define the intensity clusters for the blood pool region and the surrounding region, only a few lines drawn on the corresponding regions are required as user input. The segmentation result is a level set 3D surface in the whole volume space which can readily be constructed to form a spatial model. Our clustering based 3D level set method can also be used for segmenting other heart wall surfaces by performing appropriate initialization. By ex-tending to a 4D level set method, 4D (3D plus time) dynamic volumetric data could be readily processedpostprintProceedings of BME 2006 Biomedical Engineering Conference : biomedical engineering in education, research and industry, Hong Kong, 21-23 September 2006

New impulse (noncausality) test for descriptor systems by Mobius-transformation

Descriptor systems (DSs) are usually used to model very-large-scale integration (VLSI) circuit systems and multibody dynamics macromodeling. The analysis of DSs, however, is much more complicated than linear time-invariant (LTI) systems due to the poles at infinity. Mȯbius transformation (MT) provides a way to transform poles at infinity to finite poles and largely facilitates the reuse or adaptation of the standard techniques for LTI system to analyze DSs. Nonetheless, MT is well known in the literature and its potential use is currently less appreciated in the analysis of DSs. This paper gives a new way to the impulse (noncausality) test using the properties of the transformed LTI systems by MT. Moreover, the applications to the analysis of controllability, observability and regularity are given. Numerical examples are included to show the effectiveness of the proposed method. © 2012 Chinese Assoc of Automati.published_or_final_versio