Algorithm transformation methods to reduce the overhead of software-based fault tolerance techniques

This paper introduces a framework that tackles the costs in area and energy consumed by methodologies like spatial or temporal redundancy with a different approach: given an algorithm, we find a transformation in which part of the computation involved is transformed into memory accesses. The precomputed data stored in memory can be protected then by applying traditional and well established ECC algorithms to provide fault tolerant hardware designs. At the same time, the transformation increases the performance of the system by reducing its execution time, which is then used by customized software-based fault tolerant techniques to protect the system without any degradation when compared to its original form. Application of this technique to key algorithms in a MP3 player, combined with a fault injection campaign, show that this approach increases fault tolerance up to 92%, without any performance degradation.     

Humidity control by heat reclaim

The introduction of high‐efficiency desiccant rotors with the possibility of being regenerated by low‐temperature heat offers new opportunities to the desiccant technique in the field of air conditioning. The use of energy recovered from the condensers of the chillers or from CHP units to obtain humidity control in buildings involves a remarkable fall in the energy and operating costs for air conditioning especially in a mild climate. The reduction of installed cooling capacity is also important. The performance of air handling units that include these drying wheels are here compared with those of traditional solutions, both in energy and economic terms. The results are very promising. Copyright © 2001 John Wiley & Sons, Ltd.     

New inorganic–organic proton conducting membranes based on Nafion and [(ZrO2)·(SiO2)0.67] nanoparticles: Synthesis vibrational studies and conductivity

In this report is described the preparation of six nanocomposite membranes of formula {Nafion/_[(ZrO_2)⋅(SiO_2)0.67]ΨZrO₂}$\{\text{Nafion}/{[(\text{Zr}{\text{O}}_2)\cdot {(\text{Si}{\text{O}}_2)}_{0.67}]}_{{\Psi }_{\text{Zr}{\text{O}}_2}}\}$ with ΨZrO₂${\Psi }_{\text{Zr}{\text{O}}_2}$ ranging from 0 to 1.79 based on Nafion^® and [(ZrO₂)·(SiO₂)_0.67] nanofiller. Morphology investigations carried out by SEM measurements indicate that the composition of membranes is asymmetric. Indeed, with respect to the direction of the films after casting procedure, the top side (A-side) and bottom side (B-side) present a different nanofiller concentration. The concentration of nanofiller increases gradually from A to B side. The membranes present thicknesses ranging from 170 to 350 nm and are studied by FT-IR ATR and micro-Raman measurements.     

Presentation‐Oriented Key‐Frames Coding Based on Fractals

This paper focuses on the problem of key‐frames coding and proposes a new promising approach based on the use of fractals. The summary, made of a set of key‐frames selected from a full‐length video sequence, is coded by using a 3D fractal scheme. This allows the video presentation tool to expand the video sequence in a “natural” way by using the property of the fractals to reproduce the signal at several resolutions. This feature represents an important novelty of this work with respect to the alternative approaches, which mainly focus on the compression ratio without taking into account the presentation aspect of the video summary. In devising the coding scheme, we have taken care of the computational complexity inherent in fractal coding. Accordingly, the key‐frames are first wavelet transformed, and the fractal coding is then applied to each subband to reduce the search range. Experimental results show the effectiveness of the proposed approach.     

Phase Inversion Strategy to Flexible Freestanding Electrode: Critical Coupling of Binders and Electrolytes for High Performance Li–S Battery

Development of flexible and freestanding electrode is attracting great attention in lithium–sulfur (Li–S) batteries, but the severe capacity fading caused by the lithium polysulfides (PSs) shuttle effect remains challenging. Herein, a completely new polymeric binder of polyethersulfone is introduced. Not only it enables massive production of flexible/current‐free electrode by a novel concept of “phase‐inversion” approach but also the resultant polymeric networks can effectively trap the soluble polysulfides within the electrode, owing to the higher hydrophilicity and stronger affinity properties than the routine polyvinylidene fluoride. Coupling with polysulfide‐based electrolyte, the Li–S cell shows a higher capacity of 1141 mAh g^?1, a lower polarization of 192 mV, and a more stable capacity retention with 100% Coulombic efficiency over 100 cycles at 0.25C. The advantages of favored binder and electrolyte are further demonstrated in lithium‐ion sulfur full battery with lithiated graphite anode, which demonstrates much improved performance than those previously reported. This work not only introduces a novel strategy for flexible freestanding electrodes but also enlightens the importance of coupling electrodes and electrolytes to higher performances for Li–S battery.     

Analysis and Test of Resistive-Open Defects in SRAM Pre-Charge Circuits

In this paper, we present an exhaustive study on the influence of resistive-open defects in pre-charge circuits of SRAM memories. In SRAM memories, the pre-charge circuits operate the pre-charge and equalization at a certain voltage level, in general Vdd, of all the couples of bit lines of the memory array. This action is essential in order to ensure correct read operations. We have analyzed the impact of resistive-opens placed in different locations of these circuits. Each defect studied in this paper disturbs the pre-charge circuit in a different way and for different resistive ranges, but the produced effect on the normal memory action is always the perturbation of the read operations. This faulty behavior can be modeled by Un-Restored Write Faults (URWFs) and Un-Restored Read Faults (URRFs), because there is an incorrect pre-charge/equalization of the bit lines after a write or read operation that disturbs the following read operation. In the last part of the paper, we demonstrate that the test of URWFs is more effective in terms of resistive defect detection than that of URRFs and we list the necessary test conditions to detect them.

An Adaptive Control System to Deliver Interactive Virtual Environment Content to Handheld Devices

Wireless communication advances have enabled emerging video streaming applications to mobile handheld devices. For example, it is possible to display and interact with complex 3D virtual environments on mobile devices that don’t have enough computational and storage capabilities (e.g. smart phones, PDAs) through remote rendering techniques, where a server renders 3D data and streams the corresponding image flow to the client. However, due to fluctuations in bandwidth characteristics and limited mobile device CPU capabilities, it is extremely challenging to design effective systems for streaming interactive multimedia over wireless networks. This paper presents a novel approach based on a controller that can automatically adjust streaming parameters basing on feedback measures from the client device. Experimental results prove the effectiveness of the proposed solution in coping with bandwidth changes, thus providing high Quality of Service (QoS) in remote visualizations.     

Hybrid and optical packet switching supporting different service classes in data center network

Photonic Network Communications - Optical packet switching is a prominent technology proposing not only a reduction in the energy consumption by the elimination of numerous...