35 research outputs found
A New Chaotic System with Multiple Attractors: Dynamic Analysis, Circuit Realization and S-Box Design
This paper reports about a novel three-dimensional chaotic system with three nonlinearities. The system has one stable equilibrium, two stable equilibria and one saddle node, two saddle foci and one saddle node for different parameters. One salient feature of this novel system is its multiple attractors caused by different initial values. With the change of parameters, the system experiences mono-stability, bi-stability, mono-periodicity, bi-periodicity, one strange attractor, and two coexisting strange attractors. The complex dynamic behaviors of the system are revealed by analyzing the corresponding equilibria and using the numerical simulation method. In addition, an electronic circuit is given for implementing the chaotic attractors of the system. Using the new chaotic system, an S-Box is developed for cryptographic operations. Moreover, we test the performance of this produced S-Box and compare it to the existing S-Box studies
ImageCAS: A Large-Scale Dataset and Benchmark for Coronary Artery Segmentation based on Computed Tomography Angiography Images
Cardiovascular disease (CVD) accounts for about half of non-communicable
diseases. Vessel stenosis in the coronary artery is considered to be the major
risk of CVD. Computed tomography angiography (CTA) is one of the widely used
noninvasive imaging modalities in coronary artery diagnosis due to its superior
image resolution. Clinically, segmentation of coronary arteries is essential
for the diagnosis and quantification of coronary artery disease. Recently, a
variety of works have been proposed to address this problem. However, on one
hand, most works rely on in-house datasets, and only a few works published
their datasets to the public which only contain tens of images. On the other
hand, their source code have not been published, and most follow-up works have
not made comparison with existing works, which makes it difficult to judge the
effectiveness of the methods and hinders the further exploration of this
challenging yet critical problem in the community. In this paper, we propose a
large-scale dataset for coronary artery segmentation on CTA images. In
addition, we have implemented a benchmark in which we have tried our best to
implement several typical existing methods. Furthermore, we propose a strong
baseline method which combines multi-scale patch fusion and two-stage
processing to extract the details of vessels. Comprehensive experiments show
that the proposed method achieves better performance than existing works on the
proposed large-scale dataset. The benchmark and the dataset are published at
https://github.com/XiaoweiXu/ImageCAS-A-Large-Scale-Dataset-and-Benchmark-for-Coronary-Artery-Segmentation-based-on-CT.Comment: 17 pages, 12 figures, 4 table
Hidden attractors in fundamental problems and engineering models
Recently a concept of self-excited and hidden attractors was suggested: an
attractor is called a self-excited attractor if its basin of attraction
overlaps with neighborhood of an equilibrium, otherwise it is called a hidden
attractor. For example, hidden attractors are attractors in systems with no
equilibria or with only one stable equilibrium (a special case of
multistability and coexistence of attractors). While coexisting self-excited
attractors can be found using the standard computational procedure, there is no
standard way of predicting the existence or coexistence of hidden attractors in
a system. In this plenary survey lecture the concept of self-excited and hidden
attractors is discussed, and various corresponding examples of self-excited and
hidden attractors are considered