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Full-Text Articles in Engineering
Orthogonal Polynomial-Based Nonlinearity Modeling And Mitigation For Led Communications, Weikang Zhao, Qinghua Guo, Jun Tong, Jiangtao Xi, Yanguang Yu, Pingjuan Niu, Xiaohong Sun
Orthogonal Polynomial-Based Nonlinearity Modeling And Mitigation For Led Communications, Weikang Zhao, Qinghua Guo, Jun Tong, Jiangtao Xi, Yanguang Yu, Pingjuan Niu, Xiaohong Sun
Faculty of Engineering and Information Sciences - Papers: Part A
The light-emitting diode (LED) is the major source of nonlinearity in LED communications, and the nonlinearity needs to be effectively modeled and thereby mitigated through predistortion or postdistortion to avoid degradation of communication performance. A memory polynomial is often used for LED nonlinearity modeling and mitigation in the literature. However, the estimation of memory polynomial coefficients suffers from numerical instability, resulting in inaccurate modeling and poor performance in nonlinearity mitigation. In this paper, we propose an orthogonal polynomial-based nonlinearity modeling and mitigation technique for LED communications with pulse amplitude modulation (PAM) signaling and show that the proposed technique significantly outperforms …
Modeling Behaviour Of Railway Ballast In Prismoidal Apparatus Using Discrete Element Method, Gino O. Calderon Vizcarra, Sanjay Nimbalkar, Michele Dal Toe Casagrande
Modeling Behaviour Of Railway Ballast In Prismoidal Apparatus Using Discrete Element Method, Gino O. Calderon Vizcarra, Sanjay Nimbalkar, Michele Dal Toe Casagrande
Faculty of Engineering and Information Sciences - Papers: Part A
This article presents the results of numerical simulations of loading tests conducted on coarse particles that simulate railroad ballast. The objective of this study was to evaluate the deformation of ballast under vertical loading and to study the influence of the two different particle size distributions. One of them was according to particle size distribution recommended by Indraratna and co-workers in the past as an improvement to Australian Standard and the other was prepared in accordance with Brazilian standard. The discrete element method offers a new means of studying the response characteristics of railway ballast. The basic idea of discrete …
Modeling And Identification Of A Realistic Spiking Neural Network And Musculoskeletal Model Of The Human Arm, And An Application To The Stretch Reflex, Manish Sreenivasa, Ko Ayusawa, Yoshihiko Nakamura
Modeling And Identification Of A Realistic Spiking Neural Network And Musculoskeletal Model Of The Human Arm, And An Application To The Stretch Reflex, Manish Sreenivasa, Ko Ayusawa, Yoshihiko Nakamura
Faculty of Engineering and Information Sciences - Papers: Part B
This study develops a multi-level neuromuscular model consisting of topological pools of spiking motor, sensory and interneurons controlling a bi-muscular model of the human arm. The spiking output of motor neuron pools were used to drive muscle actions and skeletal movement via neuromuscular junctions. Feedback information from muscle spindles were relayed via monosynaptic excitatory and disynaptic inhibitory connections, to simulate spinal afferent pathways. Subject-specific model parameters were identified from human experiments by using inverse dynamics computations and optimization methods. The identified neuromuscular model was used to simulate the biceps stretch reflex and the results were compared to an independent dataset. …