2.4 GHz and 5.2 GHz Frequency Bands Reconfigurable Fractal Antenna for Wearable Devices using ANN

Patch antenna is being used widely in wearable and implantable devices due to its lightweight characteristics. Multi-band patch antenna designs are possible by incorporating professional naturally inspired fractal pattern generating methodologies. Automated Frequency Characteristics Analyzer (AFCA), Artificial Neural Network based Fractal Pattern Generator (AFPG) and Nitinol based Pattern Selector (NPS) functional modules are proposed in this work to design a Dual band Reconfigurable Fractal Antenna for Wearable Devices (DRFA). Producing a miniature fractal patch antenna to support famed 2.4 GHz and 5.2 GHz frequency bands with lesser than 20db return loss is the objective of this work. Numerous fractal patterns are generated with the help of AFPG and their frequency responses are analyzed by Ansys HFSS (High Frequency Structure Simulator) through AFCA module. The results are provided to the AFPG part to train the neural network with proper biasing updates. The fitness function is set to the dimension restriction of 3000 square μm with less than 20 return loss at commonly used 2.4 GHz and 5.2 GHz. The feed type and length of the patches are also fine-tuned by the proposed AFPG module.

A Sand-Arch Stability Constrained Dynamic Fractal Wormhole Growth Model for Simulating Cold Heavy-Oil Production with Sand

Summary Cold heavy-oil production with sand (CHOPS) is a nonthermal primary process that is widely adopted in many weakly consolidated heavy-oil deposits around the world. However, only 5 to 15% of the initial oil in place is typically recovered. Several solvent-assisted schemes are proposed as follow-up strategies to increase the recovery factor in post-CHOPS operations. The development of complex, heterogeneous, high-permeability channels or wormholes during CHOPS renders the analysis and scalability of these processes challenging. One of the key issues is how to properly estimate the dynamic growth of wormholes during CHOPS. Existing growth models generally offer a simplified representation of the wormhole network, which, in many cases, is denoted as an extended wellbore. Despite it being commonly acknowledged that wormhole growth due to sand-arch failure is likely to follow fractal statistics, there are no established workflows to incorporate sand-arch stability constraints into the construction of these fractal wormhole patterns. A novel dynamic wormhole growth model is developed to generate a set of realistic fractal wormhole networks during the CHOPS operations. It offers an improvement to the diffusion limited aggregation (DLA) algorithm with a sand-arch stability criterion. The outcome is a fractal pattern that mimics a realistic wormhole growth path, with sand-arch failure and fluidization being controlled by sand-arch stability constraints. The fractal pattern is updated dynamically by coupling compositional flow simulation on a locally refined grid and a stability criterion for the sand arch: the wormhole would continue expanding following the fractal pattern, provided that the pressure gradient at the tip exceeds the limit corresponding to a sand-arch stability criterion. Important transport mechanisms including foamy oil (nonequilibrium exsolution of gas) and sand-arch failure are integrated. Public field data for several CHOPS fields in Canada are used to examine the results of the dynamic wormhole growth model and flow simulations. For example, the sand production history is used to estimate a practical range for the critical pressure gradient representative of the sand-arch stability criterion. The oil and sand production histories show good agreement with the modeling results. In many CHOPS or post-CHOPS modeling studies, constant wormhole intensity is commonly assigned uniformly throughout the entire domain; as a result, the ensuing models are unlikely to capture the complex heterogeneous distribution of wormholes encountered in realistic reservoir settings. This work, however, proposes a novel model to integrate a set of statistical fractal patterns. The entire workflow has been readily integrated with commercial reservoir simulators, enabling it to be incorporated in practical field-scale operations design.

Design Practice of Ceramic Tea Set Based on Aesthetic Features of Fractal Pattern

The unique aesthetic characteristics of the fractal pattern are analyzed and discussed, and the aesthetic features of the fractal pattern are used to practice the appearance design and decorative pattern design of the ceramic tea set. Through the practice of product design based on fractal ideas, a set of effective and feasible ideas and methods for applying fractal ideas to product design were explored, which broadened product design ideas and tried new possibilities for product design.

COMPLEX FUNCTION PROJECTIVE SYNCHRONIZATION IN FRACTIONAL-ORDER COMPLEX NETWORKS AND ITS APPLICATION IN FRACTAL PATTERN RECOGNITION

Based on the stability theory of fractional-order systems, a projective synchronization scheme with different coefficients is realized in [Formula: see text] complex networks to build a model for fractal pattern recognition. In the proposed complex function projection synchronization scheme, first a drive-response network is constructed with [Formula: see text] fractional-order complex nodes; And then reasonable controllers are designed to realize the function projection synchronization with different projection coefficients, which are used to encode the fractal pattern; Finally, using the synchronization error system, the input variables for identifying fractal patterns can be solved, and the fractal pattern can be recognized. From the perspective of neurodynamics, the proposed model provides a better understanding of human perception system.