A Generic Foreground Calibration Algorithm For ADCs with Nonlinear Impairments

ABSTRACT We modelled the two major layer of Earth’s ionosphere, the F-layer and the D-layer, by a simplified spatial model with temporal variance to study the chromatic ionospheric effects on global 21-cm observations. From the analyses, we found that the magnitude of the ionospheric disruptions due to ionospheric refraction and absorption can be greater than the expected global 21-cm signal, and the variation of its magnitude can differ, depending on the ionospheric conditions. Within the parameter space adopted in the model, the shape of the global 21-cm signal is distorted after propagating through the ionosphere, while its amplitude is weakened. It is observed that the ionospheric effects do not cancel out over time, and thus should be accounted for in the foreground calibration at each timestep to account for the chromaticity introduced by the ionosphere.

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Minimization of the Line Resistance Impact on Memdiode-Based Simulations of Multilayer Perceptron Arrays Applied to Pattern Recognition

Journal of Low Power Electronics and Applications ◽

10.3390/jlpea11010009 ◽

2021 ◽

Vol 11 (1) ◽

pp. 9

Author(s):

Fernando Leonel Aguirre ◽

Nicolás M. Gomez ◽

Sebastián Matías Pazos ◽

Félix Palumbo ◽

Jordi Suñé ◽

...

Keyword(s):

Pattern Recognition ◽

Ex Situ ◽

Multilayer Perceptrons ◽

Spice Simulation ◽

Large Dataset ◽

High Line ◽

Calibration Algorithm ◽

The Impact ◽

Line Resistance

In this paper, we extend the application of the Quasi-Static Memdiode model to the realistic SPICE simulation of memristor-based single (SLPs) and multilayer perceptrons (MLPs) intended for large dataset pattern recognition. By considering ex-situ training and the classification of the hand-written characters of the MNIST database, we evaluate the degradation of the inference accuracy due to the interconnection resistances for MLPs involving up to three hidden neural layers. Two approaches to reduce the impact of the line resistance are considered and implemented in our simulations, they are the inclusion of an iterative calibration algorithm and the partitioning of the synaptic layers into smaller blocks. The obtained results indicate that MLPs are more sensitive to the line resistance effect than SLPs and that partitioning is the most effective way to minimize the impact of high line resistance values.

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A UWB-Driven Self-Actuated Projector Platform for Interactive Augmented Reality Applications

Applied Sciences ◽

10.3390/app11062871 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2871

Author(s):

Ahmed Elsharkawy ◽

Khawar Naheem ◽

Dongwoo Koo ◽

Mun Sang Kim

Keyword(s):

Augmented Reality ◽

Interaction Design ◽

Rapid Development ◽

Interactive Technology ◽

Ultra Wideband ◽

Wireless Sensor ◽

Interactive System ◽

Input Device ◽

Reasonable Accuracy ◽

Calibration Algorithm

With the rapid development of interactive technology, creating systems that allow users to define their interactive envelope freely and provide multi-interactive modalities is important to build up an intuitive interactive space. We present an indoor interactive system where a human can customize and interact through a projected screen utilizing the surrounding surfaces. An ultra-wideband (UWB) wireless sensor network was used to assist human-centered interaction design and navigate the self-actuated projector platform. We developed a UWB-based calibration algorithm to facilitate the interaction with the customized projected screens, where a hand-held input device was designed to perform mid-air interactive functions. Sixteen participants were recruited to evaluate the system performance. A prototype level implementation was tested inside a simulated museum environment, where a self-actuated projector provides interactive explanatory content for the on-display artifacts under the user’s command. Our results depict the applicability to designate the interactive screen efficiently indoors and interact with the augmented content with reasonable accuracy and relatively low workload. Our findings also provide valuable user experience information regarding the design of mobile and projection-based augmented reality systems, with the ability to overcome the limitations of other conventional techniques.

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