i/sub DD/ pulse response testing: a unified approach to testing digital and analogue ICs

A test method is presented for detecting defects and fabrication variations in both digital and analogue circuits by simultaneously pulsing the power supply rails and analysing the temporal and/or the spectral characteristics of the resulting transient rail currents. The presented method has a distinct advantage over other forms of i/sub DD/ testing because it requires a single test vector to excite and expose the presence of a defect or fabrication variations.<>     

Analysis, dimensional sizing and configuration comparison of switched-reluctance motors operating under multiphase excitation

The paper presents a simple approach for analyzing switched reluctance motors (SRMs) operating under multiphase excitation. The analysis results in specific design coefficients [derived from the SRM flux and magnetomotive force (MMF) distributions that can be used in a methodology] to calculate the SRMs initial dimensions while taking into account the magnetic loading and electric loading. Finally, the approach enables comparison of SRM configurations for an application without performing complete designs. The magnetic loading (i.e., saturation) and torque of various SRM configurations designed using the proposed approach are verified through finite-element analysis (FEA).     

Influence of Mesoporous Silica and Butyral Content on the Mechanical,Water Absorption,and Permeability Properties of in situ Synthesized Silica/PVB Nanocomposite Films

Poly(vinyl butyral)–silica nanocomposites were synthesized in situ with three different degrees of butyral and with varying silica content for each vinyl butyral polymer ratio. The glass transition temperatures of the polymer nanocomposites were found to be ～40–46 and ～52°C for the neat polymer, respectively. The 4 wt% silica loaded film showed higher strength and lower strain to failure compared with the neat polymer. The matrix with 0.5 and 0.75 butyral:alcohol for 2.5–4 wt% silica exhibited good water vapor transmission and the efficiencies of these films were 50% higher than their encapsulated pristine polymer films.     

The influence of applied stress rate on the stress corrosion cracking of 4340 and 3.5NiCrMoV steels in distilled water at 30 °C

Linearly Increasing Stress Tests conducted in 30 °C aerated distilled water using as-quenched 4340 and 3.5NiCrMoV turbine rotor steels indicated that stress corrosion cracking occurred at all applied stress rates for 4340 steel, whilst only at applied stress rates less than or equal to 0.002 MPa s⁻¹ for the turbine rotor steel. The crack velocity increased with increasing applied stress rate for both steels with the maximum crack velocity for 4340 steel corresponded to v_II in fracture mechanics tests in room temperature water. The fracture surface morphology was mixed mode consisting of intergranular and transgranular fracture regions.     

Impact of transmission impairments on the teletraffic performanceof wavelength-routed optical networks

In a wavelength-routed optical network, a transmitted signal remains in the optical domain over the entire route (lightpath) assigned to it between its source and destination nodes. The optical signal may have to traverse a number of crossconnect switches (XCSs), fiber segments, and optical amplifiers, e.g., erbium-doped fiber amplifiers (EDFAs). Thus, while propagating through the network, the signal may degrade in quality as it encounters crosstalk at the XCSs and also picks up amplified spontaneous emission (ASE) noise at the EDFAs. Since these impairments continue to degrade the signal quality as it progresses toward its destination, the received bit error rate (BER) at the destination node might become unacceptably high. Previous work on the lightpath routing and wavelength assignment (RWA) problem assumed an ideal physical layer and ignored these transmission impairments. The main contribution of our work is to incorporate the role of the physical layer in setting up lightpaths by employing appropriate models of multiwavelength optical devices (XCSs and EDFAs) such that the BER of a candidate lightpath can be computed, in advance, to determine if this lightpath should be used for the call. Features from existing RWA algorithms are integrated with our on-line BER calculation mechanism. Our simulation studies indicate that employing BER-based call-admission algorithms has a significant impact on the performance of realistic networks     

Modeling the [dV/dt] of the IGBT during inductive turn off

Insulated gate bipolar transistor (IGBT)-based pulsewidth modulation (PWM) inverters are commonly used in inductive load circuits such as motor control. During clamped inductive load turn off of the IGBT, high-power losses occur during two phases. Due to the large inductive motor load, the voltage across the IGBT rises to the bus voltage while carrying the full-rated current. In the second phase, the current decreases as the IGBT goes into its forward blocking mode. In this paper, the turn-off process during the first phase is analyzed in detail for the first time. A simple analytical model has been derived, based upon the initial steady-state minority carrier distribution, which allows predicting the rate of rise of the voltage during this time period where the collector current remains constant. The predictions of the analytical model are in excellent agreement with results obtained from two-dimensional (2-D) numerical simulations over a broad range of minority carrier lifetime values. This analytical model provides a good estimate (within 10%) of the power losses incurred during the first phase of turn off     

Distributed source control: a network access control for integratedbroadband packet networks

The authors propose a congestion control strategy called distributed source control (DSC), designed to address the integration of diverse traffic types in broadband packet networks. DSC is a rate-based network access control implemented at the asynchronous transfer mode (ATM) layer as a feedforward control, in conjunction with an adaptive end-to-end control between network edges. The authors examine the performance of high-speed data traffic such as large file transfers, still images, and document retrievals. The authors study DSC's integrability with real-time traffic such as voice and video. With the help of a simulation model of a broadband packet network (150 Mb/s), the authors quantify the improvement in network performance due to DSC. An analytic model for an access node under DSC is developed, and guidelines for sizing of buffers in the switch and for choosing the end-to-end window size are provided     

Wireless Industrial Monitoring and Control Using a Smart Sensor Platform

A wireless smart sensor platform (based on patent pending technologies, Ramamurthy ) targeted for instrumentation and predictive maintenance systems is presented. The generic smart sensor platform with "plug-and-play" capability supports hardware interface, payload and communications needs of multiple inertial and position sensors, and actuators, using a RF link (Wi-Fi, Bluetooth, or RFID) for communications, in a point-to-point topology. The design also provides means to update operating and monitoring parameters as well as sensor/RF link specific firmware modules "over-the-air." Sample implementations for industrial applications and system performance are discussed     

Light fragment emission during mass asymmetry relaxation in heavy-ion induced fission

Both IL-12 and IFN-gamma have been implicated as principal inducers of type 1 immune responses required for the elimination of intracellular pathogens, such as viruses. We examined the in vivo antiviral role of both cytokines during coronavirus-induced hepatitis in a mouse hepatitis virus (MHV) model. The absence of IFN-gamma function in mice with a targeted disruption of the IFN-gamma R alpha-chain gene (IFN-gamma R -/-) resulted in increased susceptibility to coronaviral hepatitis associated with augmented viral replication and increased hepatocellular injury. The mutant mice showed a type 1 lymphokine response characterized by the normal high IFN-gamma and low IL-4 production. Unlike MHV-infected wild-type mice, however, the mutant IFN-gamma R -/- mice showed no increase in IL-12 p4O gene expression, similar to that in naive animals. IL-12 treatment failed to restore host resistance in IFN-gamma R -/- mice, but significantly protected MHV-susceptible C57BL/6 mice against lethal infection, although less than IFN-gamma treatment. Mice protected by IL-12 or IFN-gamma showed resistance against an otherwise lethal second MHV infection. Our data demonstrate that despite reduced IL-12 gene expression and defective IFN-gamma R function, virus-induced IFN-gamma production can occur. Furthermore, they emphasize the pivotal antiviral role of IFN-gamma in protection against acute coronavirus-induced hepatitis.     

RPM: a rapid prototyping engine for multiprocessor systems

RPM enables rapid prototyping of different multiprocessor architectures. It uses hardware emulation for reliable design verification and performance evaluation. The major objective of the RPM project is to develop a common, configurable hardware platform to accurately emulate different MIMD systems with up to eight execution processors. Because emulation is orders of magnitude faster than simulation, an emulator can run problems with large data sets more representative of the workloads for which the target machine is designed. Because an emulation is closer to the target implementation than an abstracted simulation, it can accomplish more reliable performance evaluation and design verification. Finally, an emulator is a real computer with its own I/O; the code running on the emulator is not instrumented. As a result, the emulator looks exactly like the target machine (to the programmer) and can run several different workloads, including code from production compilers, operating systems, databases, and software utilities