Harmonic balance surrogate-based immunity modeling of a nonlinear analog circuit

A novel harmonic balance surrogate-based technique to create fast and accurate behavioral models predicting, in the early design stage, the performance of nonlinear analog devices during immunity tests is presented. The obtained immunity model hides the real netlist, reduces the simulation time, and avoids expensive and time-consuming measurements after tape-out, while still providing high accuracy. The model can easily be integrated into a circuit simulator together with additional subcircuits, e.g., board and package models, as such allowing to efficiently reproduce complete immunity test setups during the early design stage and without disclosing any intellectual property. The novel method is validated by means of application to an industrial case study, being an automotive voltage regulator, clearly showing the technique's capabilities and practical advantages

Room temperature InGaAs/InP distributed feedback laser directly grown on silicon

We report an optically pumped room-temperature O-band DFB laser, based on the buffer-less epitaxial growth of high quality InGaAs/InP waveguides directly on silicon wafer

Hierarchical Bayesian inference of the Initial Mass Function in Composite Stellar Populations

The initial mass function (IMF) is a key ingredient in many studies of galaxy formation and evolution. Although the IMF is often assumed to be universal, there is continuing evidence that it is not universal. Spectroscopic studies that derive the IMF of the unresolved stellar populations of a galaxy often assume that this spectrum can be described by a single stellar population (SSP). To alleviate these limitations, in this paper we have developed a unique hierarchical Bayesian framework for modelling composite stellar populations (CSPs). Within this framework we use a parameterized IMF prior to regulate a direct inference of the IMF. We use this new framework to determine the number of SSPs that is required to fit a set of realistic CSP mock spectra. The CSP mock spectra that we use are based on semi-analytic models and have an IMF that varies as a function of stellar velocity dispersion of the galaxy. Our results suggest that using a single SSP biases the determination of the IMF slope to a higher value than the true slope, although the trend with stellar velocity dispersion is overall recovered. If we include more SSPs in the fit, the Bayesian evidence increases significantly and the inferred IMF slopes of our mock spectra converge, within the errors, to their true values. Most of the bias is already removed by using two SSPs instead of one. We show that we can reconstruct the variable IMF of our mock spectra for signal-to-noise ratios exceeding $\sim$75.Comment: Accepted for publication in MNRAS, 16 pages, 8 figure

The performance implications of contractual design: toward a configurational perspective

This study sets out to increase our understanding of the performance implications of contracts in interfirm projects in two fundamental ways. First, relying on configurational theories, we conceptually frame contracts as bundles of functional roles that simultaneously influence the governance of interfirm projects and its performance implications. Second, we expect that the importance of particular contractual roles and the interplay between them is likely to vary across different contextual and relational settings. Using a sample of 180 interfirm innovation projects, the findings of this study carry several key theoretical and managerial implications. Whereas prior research has tended to consider the different contractual functions in isolation, our configurational perspective illuminates the relevance of looking at them in concert. Second, this study shows that different settings ask for different contractual configurations. Third, our theoretical and methodological approach allows demonstrating the notion of equifinality in terms of contract design. For managers, our findings indicate managers for interfirm innovation projects should realize that contracts can have different functions and that it is important to consider these contracts in concert. Moreover, whereas a particular contractual configuration can be high-performing in some settings, in can be low-performing in others. Based on these findings we encourage practitioners to move away from the templatization of contractual design

Monolithic integrated InP distributed bragg reflector (DBR) lasers on (001) silicon

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