Dual-mode dendritic devices enhanced neural network based on electrolyte gated transistors

As a fundamental component of biological neurons, dendrites have been proven to have crucial effects in neuronal activities. Single neurons with dendrite structures show high signal processing capability that is analogous to a multilayer perceptron, whereas oversimplified point neuron models are still prevalent in AI algorithms and neuromorphic systems and fundamentally limit their efficiency and functionality of the systems constructed. In this study, we propose a dual-mode dendritic device based on electrolyte gated transistor, which can be operated to generate both supralinear and sublinear current-voltage responses when receiving input voltage pulses. We propose and demonstrate that the dual-mode dendritic devices can be used as a dendritic processing block between weight matrices and output neurons so as to enhance the expression ability of the neural networks. A dual-mode dendrites-enhanced neural network is therefore constructed with only two trainable parameters in the second layer, thus achieving 1000× reduction in the amount of second layer parameter compared to multilayer perceptron. After training by back propagation, the network reaches 90.1% accuracy in MNIST handwritten digits classification, showing advantage of the present dual-mode dendritic devices in building highly efficient neuromorphic computing.

The working memory costs of a central attentional bottleneck in multitasking

When two (or more) tasks, each requiring a rapid response, are performed at the same time then serial processing may occur at certain processing stages, such as the response selection. There is accumulating evidence that such serial processing involves additional control processes, such as inhibition, switching, and scheduling (termed the active scheduling account). The present study tested whether the existence of serial processing in multitasking leads to a requirement for processes that coordinate processing in this way (active scheduling account) and, furthermore, whether such control processes are linked to the executive functions (EF) of working memory (WM). To test this question, we merged the psychological refractory period (PRP) paradigm with a WM task, creating a complex WM span task. Participants were presented with a sequence of letters to remember, followed by a processing block in which they had to perform either a single task or a dual task, and finally were asked to recall the letters. Results showed that WM performance, i.e. the amount of letters recalled in the correct order, decreased when performing a dual task as compared to performing a single task during the retention interval. Two further experiments supported this finding using manipulations of the dual task difficulty. We conclude that the existence of serial processing in multitasking demands additional control processes (active scheduling) and that these processes are strongly linked to the executive functions of working memory.

Image processing using a reconfigurable platform: Pre-processing block hardware architecture

<p class="CM12">Real time image processing is a challenging task in which fetching the sub image requires offset memory access apart from core processing needs. This paper aims at overcoming the offset needs for memory addressing in pre-processing blocks. Another feature of this present work is to appending the image data with customized algorithmic reequipments viz duplicating, zero padding. For KxK kernel size, the proposed hardware architecture can be programmed to fetch K pixels in one cycle, reducing the data access time. Results have been compared with software-based processing for KxK spatial filtering. performance indicates significant timing improvement using proposed pre-processing hardware block.</p>

On the application of the reachability distance in the suppression of mixed Gaussian and impulsive noise in color images

In this paper, we address the problem of mixed Gaussian and impulsive noise reduction in color images. A robust filtering technique is proposed, which is utilizing a novel concept of pixels dissimilarity based on the reachability distance. The structure of the denoising method requires the estimation of the impulsiveness of each pixel in the processing block using the introduced local reachability concept. Furthermore, we determine the similarity of each pixel in the block to the central patch consisting of the processed pixel and its neighbors. Both measures are calculated as an average of modified reachability distances to the most similar pixels of the central patch and the final filtering output is a weighted average of all pixels belonging to the processing block. The proposed technique was compared with widely used filtering methods and the performed experiments proved its satisfying denoising properties. The introduced filtering design is insensitive to outliers and their clusters introduced by the impulsive noise process, preserves details and is able to efficiently suppress the Gaussian noise while enhancing the image edges. Additionally, we proposed a method which estimates the noise contamination intensity, so that the proposed filter is able to adaptively tune its parameters.

Reversible Data Hiding Scheme Using Adaptive Block Truncation Coding Based on an Edge-Based Quantization Approach

In this paper, we provide a novel reversible data hiding method using adaptive block truncation coding based on an edge-based quantization (ABTC-EQ) approach. We exploit the characteristic not being used in ABTC-EQ. To accomplish this, we first utilized a Canny edge detector to obtain an edge image and classify each block in a cover image into two versions, edge-block and non-edge-block. Subsequently, k-means clustering was used to obtain three quantization levels and derive the corresponding bit map while the current processing block was the case of an edge-block. Then Zero-Point Fixed Histogram Shifting (ZPF-HS) was applied to embed the secret information into compressed code. The experimental results show that our method provides a high embedding capacity for each test image and performance is better than other methods.

Design of parallel and pipelined DA based OBC fir filter for software defined radio

Software Defined Radio (SDR) is a new technology used to implement different wireless communication standard for mobile communication. The Intermediate Frequency (IF) block is the most demanding block in software defined radio. The most important task in intermediate processing block is digital filtering which is carried out by Finite Impulse Response (FIR) filter. One of the major techniques for the calculation of inner product is Distributed Arithmetic (DA) based FIR filter which uses Look Up Table (LUT) to eliminate the need of multiplier. The efficiency of the DA filter is affected with the increasing number of address line and also due to its serial operation. To overcome this problem parallel and pipeline based DA filter using Offset Binary Coding (OBC) for Two Bit At A Time (2-BAAT) is proposed. Our proposed method achieves less area, low power consumption and nominal delay for SDR application.

Performance Evaluation of Optical Fiber Current Transformer based Over-current Protection

Optical Fiber Current transformers (OFCTs) are achieving increased acceptance and use in high voltage system due to their superior performance characteristics. It brings new feature to modern power system protection such as high accuracy, low weight, easy installation, and no-saturation. In this paper, a new OFCT is designed and implemented a long with a digital numeric system to protect electrical-feeder from over-current due to faults. Both the optical sensing head and electronic processing block are illustrated. A detailed experimental study to confirm the performances of the device is also reported. According to the measured values of ac rms current up to 2 kA, a calibration procedure was performed. The operational characteristics of the OFCT are investigated and three different scenarios based on Prototype were carried-out to evaluate the operation of the over-current protection using OFCT. The experiential results clearly illustrate the OFCT is capable to eliminate the distortion of the electrical signals caused by conventional (CT) and hence, greatly improving the reliability of the numerical protection system.