Classification of Activated Faults in the FlexRay-Based Networks

FlexRay communication protocol is expected to become the de-facto standard for distributed safety-critical systems. This paper classifies the effects of transient single bit-flip fault injections into the FlexRay communication controller. In this protocol, when an injected fault is activated, this may result in one or more error types, i.e.: Boundary violation, Conflict, Content, Freeze, Synchronization, Syntax, and Invalid frame. To study the activated faults, a FlexRay bus network, composed of four nodes, was modeled by Verilog HDL; and a total of 135,600 transient faults was injected in only one node, called the target node. The results show that only 9,342 of the faults (about 6.9%) were activated and their effects were observed in the network nodes. The results also show that the Synchronization error is the widespread error with the occurrence rate of 70.1%. The Invalid frame, Boundary violation, Syntax, Content, Freeze, and Conflict errors have the occurrence rates of 51.1%, 32.4%, 24.6%, 20.6%, 17.3%, and 0.0%, respectively. Among the error types, the Freeze errors are the most critical errors as they mostly result in system failures. The results also show that most of the activated faults, about 75.3%, were observed simultaneously in the target node and a neighbor node. About 11.1% of the activated faults were observed only in the target node and about 13.5% only in the neighbor node.     

A 0.36 μW/channel recorder for external ambulatory ECG recorders

There is an increasing demand for long-term ECG monitoring applications which are very low power, small size and capable of wireless data transmission. This paper presents an analog front-end and also modulator for long-term ECG recording purpose. The fully integrated system features three independent channels and a modulator. The analog front-end includes a voltage-to-time conversion and a tunable modulator to achieve a very low power consumption for wireless transmission of the data without analog to digital converter. The proposed system is designed and simulated in a \(0.18\,\upmu \hbox {m}\) CMOS technology and occupies only \(0.245\,\mathrm{mm}^{2}\). It can record ECG signal with 9.2-bit resolution while consuming only \(0.36\,\upmu {\mathrm{W}}\) per channel from a 0.9 V supply. Also, it can transmit data consuming just \(0.72\,{\upmu }\mathrm{W}\) per channel from a 0.9 V supply. The input referred noise of the readout channel is \(2.01\,\upmu {\mathrm{V}}_{{{\rm rms}}}\).     

CJBR: connected junction-based routing protocol for city scenarios of VANETs

Telecommunication Systems - In this work, a new routing protocol designed exclusively for improving the connectivity of junction-based routing in city scenarios of vehicular ad hoc networks is...     

New equalisation approach for maximising data rate in discrete multi tone systems

This article presents a new time domain equaliser (TEQ), which can be used in discrete multi-tone (DMT) systems to maximise the bit rate. The proposed TEQ is tested in the fast Fourier transform based discrete multi-tone (FFT–DMT) system, and in a proposed discrete cosine transform based discrete multi-tone (DCT–DMT) system. The objective of the proposed DCT–DMT system is to make use of the energy compaction property of the DCT to reduce the channel effects on the transmitted signals. A mathematical model of the proposed TEQ is presented. Simulation experiments have been carried out to test the effect of the proposed TEQ with the FFT–DMT system and the proposed DCT–DMT system. The results show that the performance of the DCT–DMT system with the proposed TEQ is better than the FFT–DMT system with this TEQ over the eight standard carrier serving area (CSA). The results also show that employing the proposed TEQ in the DCT–DMT system can achieve a high bit rate, ranging from 2.899?Mbps to 5.369 Mbps.     

Inkjet‐Printed Flexible Gold Electrode Arrays for Bioelectronic Interfaces

Bioelectronic interfaces require electrodes that are mechanically flexible and chemically inert. Flexibility allows pristine electrode contact to skin and tissue, and chemical inertness prevents electrodes from reacting with biological fluids and living tissues. Therefore, flexible gold electrodes are ideal for bioimpedance and biopotential measurements such as bioimpedance tomography, electrocardiography (ECG), electroencephalography (EEG), and electromyography (EMG). However, a manufacturing process to fabricate gold electrode arrays on plastic substrates is still elusive. In this work, a fabrication and low‐temperature sintering (≈200 °C) technique is demonstrated to fabricate gold electrodes. At low‐temperature sintering conditions, lines of different widths demonstrate different sintering speeds. Therefore, the sintering condition is targeted toward the widest feature in the design layout. Manufactured electrodes show minimum feature size of 62 μm and conductivity values of 5 × 10 ⁶ S m^?1. Utilizing the versatility of printing and plastic electronic processes, electrode arrays consisting of 31 electrodes with electrode‐to‐electrode spacing ranging from 2 to 7 mm are fabricated and used for impedance mapping of conformal surfaces at 15 kHz. Overall, the fabrication process of an inkjet‐printed gold electrode array that is electrically reproducible, mechanically robust, and promising for bioimpedance and biopotential measurements is demonstrated.     

An analytical approach to evaluate the coefficients of thermal expansion of textile composite materials

An analytical approach is developed to evaluate the coefficients of thermal expansion (CTE) of textile reinforced composites. At the micro level, a cylindrical composite model is employed to model the fiber/matrix thermal and mechanical interactions. The effects of voids and fiber coating on the thermal expansion coefficients of composites are considered at this level. The cylindrical model was then embedded in a macro hybrid finite element solutio structure to calculate the value of the CTE for textile composites. AS‐4/epoxy balanced plain weave textile composites were manufactured. Five different fiber volume fractions were tested for CTE. Evaluatio of the thermal expansion coefficients using the current model was compared to experimental data for in‐plane and out‐of‐plane directions.     

Optimal design of multi‐direction composite flywheel rotors

Design of composite flywheels made with reinforcement in the hoop and radial directions (Multiple Direction Composites MDC) involves a large multitude of parameters such as those related to the flywheel operation, flywheel geometry, material characteristics, material layup, and stress spatial distribution and values. The problem is further complicated because most design parameters are interactive and because one parameter cannot be optimized independent of the other parameters. Optimum structural design of MDC flywheels using nonlinear optimization via a sequential quadratic programming approach and parametric finite element analysis are used to address this problem. Numerical examples are solved to compare the efficacy of the two approaches.     

DCLRRA: Distributed cross‐layer routing and resource allocation techniques for OFDMA‐based broadband wireless networks

In this study, we develop a fully distributed routing protocol for OFDMA‐based multihop broadband wireless access (BWA) networks such as those of IEEE 802.16j. We refer to this protocol as the DCLRRA protocol. DCLRRA is based on autonomous resource allocation schemes that we also derive in this paper. The routing protocol's selection of the proper resource allocation scheme is based on whether the relay stations (RSs) are nomadic or stationary. While we develop the autonomous resource allocation schemes, we exploit the multi‐user capabilities of the OFDMA physical layer. This allows simultaneous data transmission sessions within the same neighborhood while offering a total elimination of interference between transmitting nodes. The direct result of this strategy is increased throughput with high utilization of the communication channel. We examine our routing technique to show its performance merits through extensive simulations. Copyright © 2010 John Wiley & Sons, Ltd.