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This letter presents a reliable hexagonal mesh architecture for a large-area multipoint fiber sensor system. While covering a large area, the proposed mesh architecture demarcates a large number of fiber sensing regions. Within each sensing region, a ring subnet is constructed to serve many fiber Bragg grating (FBG). In particular, the proposed sensor system incorporates the fiber laser scheme cooperation with the signal-averaging module to enhance its signal-to-noise ratio (SNR) performance. The self-restored capability of the proposed system is achieved by optical switches, allowing it to protect numerous FBG sensors against fiber break(s). A higher SNR with respect to any FBG sensor setting in our experiment is available due to the signal-averaging module. [ABSTRACT FROM PUBLISHER]

Deflection routing is a feasible approach to resolve the output contention problem in packet-switched networks when buffering of packets is not practical. In this paper, we investigate the performance of multichannel deflection-routed networks with no packet injection control, strict packet injection control, and a simple token-bucket-based packet injection control. The analytical performance models of multichannel deflection-routed networks with strict packet injection control are derived. Simulation results show that the analytical models can accurately predict the performance regardless of the network topology, number of channels, and packet injection control methods. We observed that the end-to-end throughput–delay and the packet re-transmission performance at sources can be largely improved by using simple packet injection control mechanisms such as the proposed token-bucket-based method. [ABSTRACT FROM AUTHOR]

We observe that the performance of wavelength- routed (WR) networks often suffers from asymmetric traffic and network traffic patterns differing from the original design plans. WR networks with a fixed number of channels in a given transmission direction are inflexible. Therefore, we propose reversible wavelength channels. Like a reversible lane in highway systems, a reversible wavelength channel has the flexibility of its transmission direction being configurable at the setup of a lightpath. So far reversible wavelength channels have not been discussed in WR networks even though we observe that most of the required technologies are already available. In this paper, we discuss all the required technologies for implementing reversible wavelength channels in WR networks. We demonstrate that reversible wavelength channel can provide significant performance improvement for WR networks when the traffic is asymmetric. Even if the traffic is symmetric, we also have nontrivial performance improvement with reversible wavelength channels, i.e., the blocking performance of WR networks with reversible wavelength channels will be similar to that of normal WR networks with doubling the number of fibers per link. Different implementation approaches for reversible wavelength channels are discussed. Among them, the performance of the reversible waveband approach is discussed in detail. [ABSTRACT FROM PUBLISHER]

In this paper, we propose to use a novel network architecture of multiple optical burst rings to improve the interpod communications of the internal networks of data centers. In the proposed network architecture, bursty and fast-changing interpod traffic is handled by the electrical core switches, while the relatively stationary traffic is handled via optical burst rings. Compared to previously proposed hybrid optical/electrical switching schemes of using optical circuit switches, the proposed scheme offers high interpod transmission bandwidth, supports large number of pods, requires smaller connection reconfiguration time, and has better bandwidth utilization. Moreover, the proposed scheme only employs relatively low-cost commercial optical components, making it more practical for near-term implementations. [ABSTRACT FROM PUBLISHER]

Bulk isotropic and anisotropic Nd-Fe-B magnets were synthesized by hot pressing and subsequent hot deforming melt-spun ribbons with addition of Ce using spark plasma sintering (SPS). It was found that Ce addition had a prominent effect on the bulk magnets by changing the structures of the matrix and boundary phase. With Ce-contents increasing, the magnetic properties of hot-pressed magnets increased first, then dropped and peaked at 0.5at.% Ce addition: Br=0.83\ \T, Hcj=1621\ \kA/m, (BH)m=116\ \kJ/m^3. However, the magnetic properties of anisotropic magnets deteriorated with the Ce-contents increasing. [ABSTRACT FROM PUBLISHER]

Two general-purpose decomposition methods to calculate the blocking probabilities of connection-oriented networks are presented. The methods are based on either the call status or the link status of the networks, and can significantly reduce the required computational times. A heuristic is presented to simplify the application of the proposed decomposition methods on networks with irregular topologies. Numerical examples are given to demonstrate the applications of the proposed methods. [ABSTRACT FROM AUTHOR]

The interface quality and reliability issues have shown significant importance in Cu/organic low-κ damascene integration. In this letter, a post-etch in-line electron beam (E-beam) treatment was used to modify the interface properties of sidewall barrier/organic low-κ dielectric without impairing either the film properties or the dielectric constant. X-ray photoelectron spectroscopy (XPS) analysis indicated that oxygen content at the low-κ surface, which mostly came from oxygen/moisture intake from ambient during process, was eliminated by E-beam exposure and subsequent rapid thermal annealing. As a result, Cu/organic low-κ interconnects exhibited a lower line-to-line leakage current and a higher breakdown strength. The interconnect structures, after this in-line E-beam treatment process, also showed a good reliability performance against thermal stress, with good leakage current characteristics after a 500-h burn-in at 200 °C. [ABSTRACT FROM AUTHOR]