Since real-world digital images differ in thousands ways, an adaptive multi-scale decomposition scheme adapting to images is increasingly urgently required for image analysis and applications. In this paper, a unified framework for multi-scale decomposition is developed. Instead of full using the extrema in bi-dimensional empirical mode decomposition (BEMD), edges are fully taken into account because edges play an important role in images. First, effective edges are extracted using spatial scale, intensity difference and other parameters through their coarse-to-fine edge detection approach. Given Gaussian noise series with the same variance are added to these edges repeatedly to produce extrema. Then the produced extrema on edges are employed to interpolate to calculate the mean and further the different detail components from multiple noised signals on average. Through manipulating the parameters of this framework, multiple decomposition patterns: the alternative edge-preserving multi-scale decomposition and non-edge-preserving multi-scale decomposition along with in-between transitional multi-scale decomposition can be obtained, respectively. It shows that the existing multi-scale decomposition methods of BEMD can be taken as special cases of this decomposition framework. Finally, comparisons with other methods are performed and numerous applications of this decomposition approach are explored to show its efficiency.

This study presents a novel design of a miniaturised ultra wideband (UWB) band-pass filter (BPF) by integrating quasi-lumped structure with electro-magnetic band gap (EBG) cells. The proposed filter is designed to cover the UWB bandwidth of 3.1–10.6 GHz. The UWB BPF filter design is validated using both circuit simulation and electromagnetic full wave simulation. The compact UWB BPF is simulated, fabricated and the performance metrics are measured. A good agreement between simulated and measured results is obtained. Good performances such as return loss better than 14 dB, upper stop-band attenuation better than 20 dB and good selectivity are achieved.

Although extensive studies have been conducted on inter-area oscillation detection and analysis by using phasor measurement data, few have focused on inter-area oscillation statistics due to the lack of considerably long-term and high-resolution recorded data. A preliminary statistical analysis on the inter-area oscillations that occurred in the U.S. Eastern interconnection from 2010 to 2015 is presented. These oscillation events were captured and recorded by the wide-area frequency monitoring network FNET/GridEye. Oscillation occurrence, dominant frequency, damping ratio and oscillation excitation types are investigated to explore the statistical characteristics of the detected inter-area oscillations. The results from this paper will provide valuable information for system operators and planners regarding network operation and future grid development.

A wireless sensor network (WSN) is a wireless network containing of spatially distributed autonomous nodes utilising sensors to evaluate the physical or environmental circumstances. In several critical applications, an external user can directly monitor the real-time information from sensor nodes. In this case, before providing access, authenticity of the user is required to be proved by a suitable technique. Thus, in critical WSNs based real-time applications, authenticity of the users are very significant. Till now, many techniques have been developed to design a secure protocol for WSNs, to prevent unauthorised access. However, these techniques are vulnerable to wormhole attacks, which happen due to lesser synchronisation among the sensor nodes. Therefore, to handle this problem, an integrated modified-signature and recommendation-based trust evaluation protocol for WSNs is proposed. The extensive experiments have shown that the proposed technique outperforms over the available approaches.

A method for selecting a set of coupling and by-pass capacitors is presented. The approach uses short-circuit time-constant analysis and for a given −3 dB cut-off frequency minimises the total capacitance used. This study offers a derivation of design formulas and shows their use via examples.