Hybrid Fusion Scheme Research Articles

Hybrid image fusion scheme using self-fractional Fourier functions and multivariate empirical mode decomposition

Image fusion has emerged as a promising area of research and a bivariate empirical mode decomposition based fusion scheme has recently been proposed in the literature. In this paper, a hybrid fusion scheme combining self-fractional Fourier function (SFFF) decomposition and multivariate empirical mode decomposition is proposed. In the proposed image fusion technique, images to be fused are decomposed into SFFF images. The SFFF images are further decomposed into intrinsic mode functions (IMFs) using multivariate empirical mode decomposition (MEMD). Corresponding IMFs of same decomposition level of SFFF images are fused using local variance based adaptive weight fusion rule to obtain fused IMF images. The fused image is obtained by applying inverse transformation on fused IMF images. The proposed technique provides flexibility in the number of functions in the SFFF decomposition, transform before SFFF decomposition, and the types of source images (real and complex) to be fused. Simulations are performed for fusion of test images with different SFFF decomposition levels and the results are compared with other existing methods. It is seen that the simulation results are comparable to the existing schemes.

Primary User Detection for Cognitive Radio Networks Having Multi-Antennas at Their Base-Stations

Spectrum sensing is a key enabling functionality in a cognitive radio (CR) network. The fusion problem of cooperative spectrum sensing, for a cognitive radio network equipped with multi-antennas at its base-station, is considered in this paper. The base-station equipped with multi-antennas act as a fusion center which can attain not only the soft information (average power) by its multi-antennas but also the soft or hard information from other cognitive radio users (CR users). We first discuss the soft fusion scheme in which soft information from CR users is sent to the base-station, and exhibit the necessity of deeper cooperation. Due to the limitation of control channel bandwidth, CR users have to send hard information to the base-station. To this end, we propose a hybrid fusion scheme in which both soft and hard information can be fused in the base-station. Furthermore, we present an optimal cooperative spectrum sensing scheme where the global detection probability can be maximized according to the Neyman-Pearson criterion. Extensive simulation results validate that, by using the hybrid fusion scheme, significant improvement on sensing performance can be achieved. 

Magnetically Insulated Inertial Fusion-A Hybrid Fusion Scheme

An innovative scheme of inertial fusion is introduced in which the plasma pressure is contained by a metallic shell while its heat is contained by a magnetic field. The scheme utilizes a self-generated, force-free magnetic field of≥102 T in a plasma with a density of-1021 cm-3 and a temperature of-10 keV which are produced by a laser and/or a particle beam in a hard electrically conducting shell. This new scheme can resolve some fundamental difficulties encountered in both magnetic and inertial fusions.