Neural scheduler for real-time packet switching

To resolve transmission conflict in space-division packet switches, it is necessary to find a conflict-free switching schedule with a fixed and short duration. A neural scheduler is proposed for real-time conflict resolution in space-division packet switches. This neural scheduler has smaller mean and variance of the number of iterations compared to existing ones, and can guarantee that P [required number of iterations ⩽n] ⩾P* where n and P* are the requirements specified by the user     

Efficient computation for structures consisting of a slot and ametallic/dielectric hemispherical cavity

The problem of a slot associated with a metallic or dielectric hemispherical cavity is solved using the method of moments. A computationally efficient formula is presented for efficient calculations of the admittance matrix. The theory is very helpful to the design engineer as it involves substantially simpler mathematical calculations     

One dimensional scaling of 100 ridge waveguide amplifiers

We have demonstrated the concept of scaling large numbers of laser diodes to achieve high power with good beam quality. We have achieved a system based on scaling 100 ridge waveguide amplifiers with a coherent optical signal distribution network and phase modulators on a 12.2 mm×4.4 mm chip called a unit cell. The unit cell delivers 1.63 W of CW power in the central lobe with diffraction-limited performance. A high performance cooler allows high power CW performance. A custom lens array and computer-controlled phase modulators allow the beam to be collimated with flat phase front     

Fast converging LMS equaliser

A simple and efficient method is presented that makes use of a predictor to reduce the eigenvalue spread (ES) of the input signal for improving the convergence rate of the least mean square (LMS) adaptive equaliser. The performance is analysed by using a Gaussian assumption and is shown to be in good agreement with the simulations.<>     

Spatial temperature profiles due to nonuniform self-heating inLDMOS's in thin SOI

Temperature profiles resulting from self-heating in SOI-LDMOS devices with uniformly doped and linearly graded drift regions were measured using a resistance thermometry technique. Two-dimensional electrothermal device simulations were performed and the results agreed with the experiments. Because of the different power dissipation profiles, RESURF devices with a uniformly doped drift region assume a fairly uniform temperature distribution while devices with a linearly graded drift region have a much higher temperature rise near the source than the drain. This local hot spot near the source raises reliability issues in device design     

Some isomorphically polyhedral orlicz sequence spaces

A Banach space is polyhedral if the unit ball of each of its finite dimensional subspaces is a polyhedron. It is known that a polyhedral Banach space has a separable dual and isc ₀-saturated, i.e., each closed infinite dimensional subspace contains an isomorph ofc ₀. In this paper, we show that the Orlicz sequence spaceh _M is isomorphic to a polyhedral Banach space if lim _t→0 M(Kt)/M(t)=∞ for someK<∞. We also construct an Orlicz sequence spaceh _M which isc ₀-saturated, but which is not isomorphic to any polyhedral Banach space. This shows that beingc ₀-saturated and having a separable dual are not sufficient for a Banach space to be isomorphic to a polyhedral Banach space.     

Reducing the cost variance in life testing of integrated circuits

The cost of life testing of integrated circuits (ICs) varies statistically. It is desirable to reduce the testing cost variance in order to reduce the chance of paying a testing cost that is much larger than the mean. In this paper, we study two methods for reducing the testing cost variance. The first method uses the technique of weighted sum of objective functions to integrate the objective of minimizing the mean testing cost and the objective of minimizing the testing cost variance. In the second method, the test engineer inspects the progress of life testing iteratively, collects failure information and then estimates the expected remaining testing cost. If this cost is unacceptably large, he replaces the failed ICs by the functioning ones and/or adds extra IC testers     

Three-dimensional thermal deformations observed in SMT assembly during power cycling

The three-dimensional displacement fields of thermal-force coupling fatigue in a surface mounted plastic-quad-flat-pack (PQFP) assembly during power cycling by using the combination of holographic interferometry and high sensitivity moire interferometry is presented in this paper. Detailed in-plane and out-of-plane whole-field displacement data of the top and bottom ends of gull wing leads and their distributions along the edge of PQFP are provided. It was found that the maximum deformations of gull wing leads occur at the four corners of PQFP. The result presented herein should be useful in the evaluation of thermal fatigue damage mechanism of surface mount assemblies.     

Deployment issues of CCS links on self-healing rings

Fiber-based self-healing rings (SHRs) are being deployed for trunking purposes for voice/data/video services because of their high reliability and survivability. To reduce deployment and maintenance costs of provisioning different facilities for these services and common channel signaling (CCS) networks, network planners have begun to deploy CCS network signaling links on SHRs. This paper examines some issues of deploying A/B/C/D link sets on SHRs