Permutation-based finite implicative fuzzy associative memories

Implicative fuzzy associative memories (IFAMs) are single layer feedforward fuzzy neural networks whose synaptic weights and threshold values are given by implicative fuzzy learning. Despite an excellent tolerance with respect to either pasitive or negative noise, IFAMs are not suited for patterns corrupted by mixed noise. This paper presents a solution to this problem. Precisely, we first introduce the class of finite IFAMs by replacing the unit interval by a finite chain L. Then, we generalize both finite IFAMs and their dual versions by means of a permutation on L. The resulting models are referred to as permutation-based finite IFAMs (π-IFAMs). We show that a π-IFAM can be viewed as a finite IFAM, but defined on an alternative lattice structure (L,?). Thus, π-IFAMs also exhibit optimal absolute storage capacity and one step convergence in the autoassociative case. Furthermore, computational experiments revealed that a certain π-IFAM, called Lukasiewicz π_μ-IFAM, outperformed several other associative memory models for the reconstruction of gray-scale patterns corrupted by salt and pepper noise.     

PIMOD processing and properties of a LiNbO3-based MFSFET for nonvolatile memories

Abstract

The photo-induced metallo-organic decomposition (PIMOD) process has been successfully used to deposit a lithium niobate thin film acting as the gate oxide of the conventional MFSFET structure. The use of the low-temperature PIMOD process for thin film deposition has increased the device yields of the molybdenum liftoff for small area isolation. The electronic alteration of the properties of the ferroelectric gate transistor was previously shown to be caused by charges in the semiconductor being injected into the ferroelectric film. To prevent this problem, a thin SiO₂ buffer layer was thermally grown on the silicon substrate immediately before lithium niobate deposition. The silicon-lithium niobate interface was stabilized and the charge injection effect was eliminated due to the formation of the buffer layer. The channel current was shown to be greatly altered by the application of voltage pulses between the gate of the device and the substrate. Upon switching, the change in surface conductivity of the semiconductor was the same as that expected for ferroelectric switching.     

Analysis of nitride storage non-volatile memories with HfSiOx blocking dielectric and TiN metal gate for low power embedded applications

Nitride storage non-volatile memories with hafnium silicate (HfSiO_x) blocking dielectric and titanium nitride (TiN) metal gate aimed at low power embedded applications beyond the 45 nm node, have been fabricated and investigated. In addition to presenting the typical figures of merit of flash memories, the scalability of the devices has been assessed. We have also investigated the physical origin of the observed memory features.     

A shapeshifting evolvable hardware mechanism based on reconfigurable memFETs crossbar architecture

In this work, a new technologic strategy that allows implementing large crossbars formed with memFETs, a new device concept, is introduced. This memFET is an electrically reconfigurable field effect and resistive switching device that can be used to implement logic functions and memory blocks into a crossbar structure, allowing the dynamic logic configuration of the crossbar and simplifying both the design and the implementation of computing hardware. Moreover, taking the advantage of reconfiguration capability of such a technology and architecture we introduce a novel technique to design evolvable hardware where not only the logic functions are changeable (as is the case of the Field Programmable Gate Array, FPGA) but also the physical position of the components on the surface of the integrated circuit. This technology and principle leads towards a new computing paradigm based on what we name Shape Shifting Digital Hardware (SSDH).     

Reality Monitoring in Adults Reporting Repressed, Recovered, or Continuous Memories of Childhood Sexual Abuse.

People who report either repressed or recovered memories of childhood sexual abuse (CSA) may have deficits in reality monitoring--the process whereby one discriminates memories of percepts from memories of images. Using signal detection methods, the authors found that adults reporting either repressed or recovered memories of CSA were less able to discriminate between words they had seen from words they had imagined seeing than were adults reporting either never having forgotten their CSA or adults reporting no history of CSA. Relative deficits in the ability to discriminate percepts from images (i.e., low d') were apparent on only some tests. The groups did not differ in their criterion--response bias--for affirming having seen versus imagined stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Area–time issues in the VLSI implementation of self organizing map neural networks

This paper presents an efficient parallel architecture for Kohonen's Self Organizing Map Neural Networks (SOM) and analyzes the area–time complexities. The proposed SIMD architecture for the SOM facilitates its use in real-time applications like video processing. The operations of norm computation and weight update are done by the individual neurons and that of winner determination is carried out by a global, serial or parallel logic. Two methods for winner determination are presented and their time, area and networking complexities are studied. Optimal techniques for the retrieval of the winner's index are also proposed for the two methods and their complexities are investigated.     

采用双口SRAM的PC微机多功能接口电路

介绍了一种用双口ＳＲＡＭ构成的ＰＣ微机多功能接口电路的硬件设计、应用及特点。该电路可实现ＰＣ机与ＰＣ机或者ＰＣ机与单片机之间的高速数据通信；作为单片机的ＲＯＭ仿真开发机；由用户开发各种ＰＣ机ＲＯＭ仿真软件等多种功能，有较强的实用性。     

Multi‐Nonvolatile State Resistive Switching Arising from Ferroelectricity and Oxygen Vacancy Migration

Resistive switching phenomena form the basis of competing memory technologies. Among them, resistive switching, originating from oxygen vacancy migration (OVM), and ferroelectric switching offer two promising approaches. OVM in oxide films/heterostructures can exhibit high/low resistive state via conducting filament forming/deforming, while the resistive switching of ferroelectric tunnel junctions (FTJs) arises from barrier height or width variation while ferroelectric polarization reverses between asymmetric electrodes. Here the authors demonstrate a coexistence of OVM and ferroelectric induced resistive switching in a BaTiO₃ FTJ by comparing BaTiO₃ with SrTiO₃ based tunnel junctions. This coexistence results in two distinguishable loops with multi‐nonvolatile resistive states. The primary loop originates from the ferroelectric switching. The second loop emerges at a voltage close to the SrTiO₃ switching voltage, showing OVM being its origin. BaTiO₃ based devices with controlled oxygen vacancies enable us to combine the benefits of both OVM and ferroelectric tunneling to produce multistate nonvolatile memory devices.     

Ferroelectrics as Smart Mechanical Materials

The mechanical properties of materials are insensitive to space inversion, even when they are crystallographically asymmetric. In practice, this means that turning a piezoelectric crystal upside down or switching the polarization of a ferroelectric should not change its mechanical response. Strain gradients, however, introduce an additional source of asymmetry that has mechanical consequences. Using nanoindentation and contact‐resonance force microscopy, this study demonstrates that the mechanical response to indentation of a uniaxial ferroelectric (LiNbO₃) does change when its polarity is switched, and use this mechanical asymmetry both to quantify its flexoelectricity and to mechanically read the sign of its ferroelectric domains.