Single CAN Research Articles

Mixed-Criticality Systems based on a CAN Router with Support for Fault Isolation and Selective Fault-Tolerance

In many application domains there is an increasing trend for mixed-criticality systems with functions of different assurance levels on shared computing platforms. Today's CAN-based platforms do not support the requirements of mixed-criticality systems. A single CAN bus provides low cost, real-time support and flexibility for applications where the communication service is not safety-relevant. Fault-tolerance extensions for CAN impose incompatibility to legacy applications, high cost and overhead for the entire CAN communication. This paper introduces a CAN infrastructure for fault isolation and selective fault-tolerance, which permits a balanced trade-off between cost and fault-tolerance for each subsystem of a mixed-criticality system. We introduce replicated CAN routers that perform fault isolation based on a priori knowledge of the permitted behavior of CAN nodes. Fault masking is supported selectively through the redundant transmission of messages from safety-critical subsystems. The CAN routers perform input agreement on pending messages for replica deterministic behavior, as well as output agreement on the delivery status of messages. Software layers hide the fault-tolerance mechanisms to establish compatibility to legacy software. The benefits of the proposed communication infrastructure are demonstrated in a simulation of an example system.

A CAN Topology Optimization of Pure Electric Vechicle

In the design of CAN network system, as CAN bus topology will affect network performance and cost, it is important to optimize the network topology. This paper analyzes the CAN busload based on CAN protocol, calculates the upper limit of transmission message frames in a single CAN bus. As the amount of information on the bus is increasing, a single CAN bus cannot meet the communication requirements, we put forward dividing the network into multiple homogeneous segments via multi-objective optimization method, developing a genetic algorithm strategy and solving the problem in a MATLAB platform. Finally utilize the method to design a pure electric vehicle network topology.

Alternate13C−12C Labeling for Complete Mainchain Resonance Assignments using Cα Direct-Detection with Applicability Toward Fast Relaxing Protein Systems

Experiments that use direct (13)C detection and take advantage of the slower relaxation of (13)C magnetization compared to (1)H offer an attractive strategy for extending the limits of NMR to include larger, highly dynamic, or paramagnetic proteins. Because carbonyl carbons ((13)C') suffer from serious relaxation enhancement as a consequence of their large chemical shift anisotropy, deuterated alpha carbons are the preferred nuclei for (13)C detection in large and/or fast relaxing systems. However, direct detection of (13)C alpha is not straightforward owing to the presence of one-bond (13)C-(13)C couplings with (13)C' and (13)C beta that split the signals into multiples and hence reduce the sensitivity. Here we present the use of (13)C enrichment at alternating carbon sites and deuteration at the C alpha position to overcome these difficulties. The desired labeling pattern is achieved by expressing the protein in E. coli in D(2)O with either [2-(13)C] or [1,3-(13)C] glycerol as the carbon source. With this labeling strategy, we show that complete assignment of the main chain (including prolyl residues) can be achieved with a single CaN HSQC experiment. This approach offers advantages for the detection of NMR signals from sites with fast nuclear relaxation and offers promise for investigations of larger proteins and/or protein complexes that are inaccessible by proton-detected experiments.