Finding k-Dissimilar Paths with Minimum Collective Length

Shortest path computation is a fundamental problem in road networks. However, in many real-world scenarios, determining solely the shortest path is not enough. In this paper, we study the problem of finding k-Dissimilar Paths with Minimum Collective Length (kDPwML), which aims at computing a set of paths from a source s to a target t such that all paths are pairwise dissimilar by at least \theta and the sum of the path lengths is minimal. We introduce an exact algorithm for the kDPwML problem, which iterates over all possible s-t paths while employing two pruning techniques to reduce the prohibitively expensive computational cost. To achieve scalability, we also define the much smaller set of the simple single-via paths, and we adapt two algorithms for kDPwML queries to iterate over this set. Our experimental analysis on real road networks shows that iterating over all paths is impractical, while iterating over the set of simple single-via paths can lead to scalable solutions with only a small trade-off in the quality of the results.Comment: Extended version of the SIGSPATIAL'18 paper under the same titl

On the test of single via related defects in digital VLSI designs

Vias are critical for digital circuit manufacturing, as they represent a common defect location, and a general DfM rule suggests replicating every instance for redundancy. When this is not achievable, a mandatory requirement is that the remaining single vias must be tested. We propose an automated method for generating tests and accurately evaluating test coverage of such defects, ready for use in any digital implementation flow and for integration within EDA tools, and also providing a useful quality metric. A prototype tool implementation and experimental results for an industrial case study are presented

Generation of passive macromodels from transient port responses

Abstract: This paper presents a new technique for the generation of linear lumped macromodels from input-output port characterization. A complete set of transient port responses is processed by a new time-domain formulation of the well-known Vector Fitting algorithm. The data processing involves a combination of digital filtering and least squares fitting. Passivity of the obtained macromodel is enforced a posteriori by applying an iterative perturbation technique to the associated Hamiltonian matrix.

Passivity Enforcement via Perturbation of Hamiltonian Matrices

This paper presents a new technique for the passivity enforcement of linear time-invariant multiport systems in statespace form. This technique is based on a study of the spectral properties of related Hamiltonian matrices. The formulation is applicable in case the system input-output transfer function is in admittance, impedance, hybrid, or scattering form. A standard test for passivity is first performed by checking the existence of imaginary eigenvalues of the associated Hamiltonian matrix. In the presence of imaginary eigenvalues the system is not passive. In such a case, a new result based on first-order perturbation theory is presented for the precise characterization of the frequency bands where passivity violations occur. This characterization is then used for the design of an iterative perturbation scheme of the state matrices, aimed at the displacement of the imaginary eigenvalues of the Hamiltonian matrix. The result is an effective algorithm leading to the compensation of the passivity violations. This procedure is very efficient when the passivity violations are small, so that first-order perturbation is applicable. Several examples illustrate and validate the procedure

A test chip for automatic reliability measurements of interconnect vias

A test circuit for electromigration reliability measurements was designed and tested. The device under test (DUT) is a via-hole chain. The test circuit permits simultaneous measurements of a number of DUTs, and a fatal error of one DUT does not influence the measurement results of the other DUTs. Measurements require only a few measurement instruments. Comparing the measurement results of a single DUT io the measurement results of the test circuit shows that the test circuit may be used for reliability measurements

Single production of doubly charged Higgs bosons at hadron colliders

We reconsider the single production of the doubly charged Higgs bosons Delta_R^{++} and Delta_L^{++} at the LHC and TEVATRON in the framework of the left-right symmetric model and the Higgs triplet model. We show that in the left-right symmetric model the production of Delta_R^{++} by Drell-Yan process via W_R exchange may give the dominant contribution. The same channel for the production of Delta_L^{++} in the Higgs triplet model is insignificant.Comment: 11 pages 5 figure