Compute and Memory Efficient Universal Sound Source Separation

Journal of Signal Processing Systems - Recent progress in audio source separation led by deep learning has enabled many neural network models to provide robust solutions to this fundamental...     

95 GHz millimeter wave signal generation using an arrayed waveguide grating dual wavelength semiconductor laser

We report the generation of a 95?GHz carrier frequency by optical heterodyning of two wavelengths from adjacent channels from an arrayed waveguide grating-based multiwavelength laser. The extended cavity structure of the device provides low phase noise and narrow optical linewidth, further enhanced by the intracavity filter effect of the arrayed waveguide grating. We demonstrate that the generated RF beat note, at 95?GHz, has a -3 dB linewidth of 250?kHz. To the best of our knowledge, this is the narrowest RF linewidth generated from a free-running dual-wavelength semiconductor laser. The device is realized as a photonic integrated circuit using active-passive integration technology, and fabricated on a multiproject wafer run, constituting a novel approach for a compact, low-cost dual-wavelength heterodyne source.     

Global approximation to arbitrary cost functions: A Bayesian approach with application to US banking

This paper proposes and estimates a globally flexible functional form for the cost function, which we call Neural Cost Function (NCF). The proposed specification imposes a priori and satisfies globally all the properties that economic theory dictates. The functional form can be estimated easily using Markov Chain Monte Carlo (MCMC) techniques or standard iterative SURE. We use a large panel of U.S. banks to illustrate our approach. The results are consistent with previous knowledge about the sector and in accordance with mathematical production theory.     

An improved multi-staged algorithmic process for the solution of the examination timetabling problem

The efficient creation of examination timetables is a recurring and important problem for universities worldwide. Good timetables typically are characterized by balanced distances between consecutive exams for all students. In this contribution an approach for the examination timetabling problem as defined in the second International Timetabling Competition () is presented. The solution approach is managed on the top level by GRASP (Greedy Randomized Adaptive Search Procedure) and it involves several optimization algorithms, heuristics and metaheuristics. A construction phase is executed first producing a relatively high quality feasible solution and an improvement phase follows that further ameliorates the produced timetable. Each phase consists of stages that are consumed in a circular fashion. The procedure produces feasible solutions for each dataset provided under the runtime limit imposed by the rules of the ITC07 competition. Results are presented and analyzed.     

Realization of a Framework for Simulation-Based Large-Scale Shape Optimization Using Vertex Morphing

Journal of Optimization Theory and Applications - There is a significant tendency in the industry for automation of the engineering design process. This requires the capability of analyzing an...     

Development and Application of Instrumental Methods for Strain Analysisof Semiconductor Layers and Devices

 Strain effects on semiconductor layers were studied by means of optical spectroscopic techniques with a device developed especially for the study of layered structures and microstructures. Raman, modulated photoreflectance and reflectance anisotropy spectroscopy (RAS) were applied. Measurements were performed on elemental semiconductors (Si), semiconductor alloys (Si–Ge) and III–V semiconductor compounds (GaAs). By application of RAS, strains lower than 10⁻⁴ could be resolved, which is at least one order of magnitude lower than those observable with Raman and modulated reflectance techniques. The RAS spectra of layers strained along either the [010] or [011] direction showed a derivative-like structure at E₁-gap energies, which increased linearly and very quickly with increasing strain. The dependence of this spectral feature on applied strain was used to evaluate strain-dependent effects. This behaviour strongly suggests that RAS can be applied for the optical characterisation of strain in semiconductor microstructures and devices, with a higher efficiency and accuracy than that achieved by previously established optical methods such as Raman and modulation spectroscopy. In addition, the compactness and ease of operation of the instrumentation of RAS provides considerable potential for in situ monitoring/control of semiconductor fabrication conditions.