Results for "Tijmen Blankevoort"

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Relaxed Quantization for Discretized Neural NetworksOct 03 2018Neural network quantization has become an important research area due to its great impact on deployment of large models on resource constrained devices. In order to train networks that can be effectively discretized without loss of performance, we introduce ... More
Data-Free Quantization through Weight Equalization and Bias CorrectionJun 11 2019We introduce a data-free quantization method for deep neural networks that does not require fine-tuning or hyperparameter selection. It achieves near-original model performance on common computer vision architectures and tasks. 8-bit fixed-point quantization ... More
Improved Performance of TES Bolometers using Digital FeedbackOct 17 2012Voltage biased, frequency multiplexed TES bolometers have become a widespread tool in mm-wave astrophysics. However, parasitic impedance and dynamic range issues can limit stability, performance, and multiplexing factors. Here, we present novel methods ... More
One-step deposition of nano-to-micron-scalable, high-quality DIC patterns for high-strain in-situ multi-microscopy testingApr 26 2019Digital Image Correlation (DIC) is of vital importance in the field of experimental mechanics, yet, producing suitable DIC patterns for challenging in-situ mechanical tests remains challenging, especially for ultra-fine patterns, despite the large number ... More
Spatial homogeneity of optically switched semiconductor photonic crystals and of bulk semiconductorsOct 19 2004This paper discusses free carrier generation by pulsed laser fields as a mechanism to switch the optical properties of semiconductor photonic crystals and bulk semiconductors on an ultrafast time scale. Requirements are set for the switching magnitude, ... More
Demonstrating the potential of Accurate Absolute Cross-grain Stress and Orientation correlation using Electron Backscatter DiffractionJul 11 2018Nov 23 2018We report a first exploration of High-angular-Resolution Electron Backscatter Diffraction, without using simulated Electron Backscatter Diffraction patterns as a reference, for absolute stress and orientation measurements in polycrystalline materials. ... More
Broadband sensitive pump-probe setup for ultrafast optical switching of photonic nanostructures and semiconductorsMar 01 2009We describe an ultrafast time resolved pump-probe spectroscopy setup aimed at studying the switching of nanophotonic structures. Both fs pump and probe pulses can be independently tuned over broad frequency range between 3850 and 21050 cm$^{-1}$. A broad ... More
Identification of competing ultrafast all-optical switching mechanisms in Si woodpile photonic crystalsJul 28 2008Apr 22 2009We present a systematic study of ultrafast all-optical switching of Si photonic band gap woodpile crystals using broadband tunable nondegenerate pump-probe spectroscopy. At pump-probe coincidence, we investigate the behavior the differential reflectivity ... More
Lensing Noise in mm-wave Galaxy Cluster SurveysOct 23 2012We study the effects of gravitational lensing by galaxy clusters of the background of dusty star-forming galaxies (DSFGs) and the Cosmic Microwave Background (CMB), and examine the implications for Sunyaev-Zel'dovich-based (SZ) galaxy cluster surveys. ... More
The Privacy Coach: Supporting customer privacy in the Internet of ThingsJan 25 2010The Privacy Coach is an application running on a mobile phone that supports customers in making privacy decisions when confronted with RFID tags. The approach we take to increase customer privacy is a radical departure from the mainstream research efforts ... More
Kinetics of 2D-constrained orbitally-shaken particlesSep 28 2017Aug 16 2018We present an experimental study of the kinetics of orbitally-shaken macroscopic particles confined to a two-dimensional bounded domain. Discounting the forcing action of the external periodic actuation, the particles show translational velocities and ... More
Dynamical ultrafast all-optical switching of planar GaAs/AlAs photonic microcavitiesJun 15 2007Sep 11 2007The authors study the ultrafast switching-on and -off of planar GaAs/AlAs microcavities. Up to 0.8% refractive index changes are achieved by optically exciting free carriers at 1720 nm and a pulse energy of 1.8 micro Joules. The cavity resonance is dynamically ... More
RF-dressed Rydberg atoms in hollow-core fibresMar 29 2016The giant electro-optical response of Rydberg atoms manifests itself in the emergence of sidebands in the Rydberg excitation spectrum if the atom is exposed to a radio-frequency (RF) electric field. Here we report on the study of RF-dressed Rydberg atoms ... More
All-optical octave-broad ultrafast switching of Si woodpile photonic band gap crystalsMar 06 2006Dec 13 2007We present ultrafast all-optical switching measurements of Si woodpile photonic band gap crystals. The crystals are spatially homogeneously excited, and probed by measuring reflectivity over an octave in frequency (including the telecom range) as a function ... More
Excitation of higher-order modes in optofluidic photonic crystal fiberJul 23 2018Higher-order modes up to LP$_{33}$ are controllably excited in water-filled kagom\'{e}- and bandgap-style hollow-core photonic crystal fibers (HC-PCF). A spatial light modulator is used to create amplitude and phase distributions that closely match those ... More
Long-range optical trapping and binding of microparticles in hollow-core photonic crystal fibreSep 12 2017Optically levitated micro- and nanoparticles offer an ideal playground for investigating photon-phonon interactions over macroscopic distances. Here we report the observation of long-range optical binding of multiple microparticles, mediated by intermodal ... More
Long term observation of Magnetospirillum gryphiswaldense in a microfluidic channelFeb 21 2019We controlled and observed individual magnetotactic bacteria (Magnetospirillum gryphiswaldense) inside a 5 {\mu}m high microfluidic channel for over four hours. After a period of constant velocity, the duration of which varied between bacteria, all observed ... More
A thermodynamic description of turbulence as a source of stochastic kinetic energy for 3D self-assemblyJun 07 2019We investigate to what extent one can use a thermodynamic description of turbulent flow as a source of stochastic kinetic energy for three-dimensional self-assembly of magnetically interacting macroscopic particles. We confirm that the speed of the objects ... More
Ultrafast optical switching of three-dimensional Si inverse opal photonic band gap crystalsMay 29 2007Sep 19 2007We present ultrafast optical switching experiments on 3D photonic band gap crystals. Switching the Si inverse opal is achieved by optically exciting free carriers by a two-photon process. We probe reflectivity in the frequency range of second order Bragg ... More
Digital frequency domain multiplexing readout electronics for the next generation of millimeter telescopesJul 11 2014Frequency domain multiplexing (fMux) is an established technique for the readout of transition-edge sensor (TES) bolometers in millimeter-wavelength astrophysical instrumentation. In fMux, the signals from multiple detectors are read out on a single pair ... More
Adaptation of frequency-domain readout for Transition Edge Sensor bolometers for the POLARBEAR-2 Cosmic Microwave Background experimentJun 08 2013Jul 04 2013The POLARBEAR-2 CosmicMicrowave Background (CMB) experiment aims to observe B-mode polarization with high sensitivity to explore gravitational lensing of CMB and inflationary gravitational waves. POLARBEAR-2 is an upgraded experiment based on POLARBEAR-1, ... More
Having Fun in Learning Formal SpecificationsMar 01 2019There are many benefits in providing formal specifications for our software. However, teaching students to do this is not always easy as courses on formal methods are often experienced as dry by students. This paper presents a game called FormalZ that ... More
Optical Characterization of the SPT-3G Focal PlaneMay 08 2018The third-generation South Pole Telescope camera is designed to measure the cosmic microwave background across three frequency bands (95, 150 and 220 GHz) with ~16,000 transition-edge sensor (TES) bolometers. Each multichroic pixel on a detector wafer ... More
CMB-S4 Science Book, First EditionOct 10 2016This book lays out the scientific goals to be addressed by the next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned to consist of dedicated telescopes at the South Pole, the high Chilean Atacama plateau and possibly ... More
CMB-S4 Technology Book, First EditionJun 08 2017Jul 06 2017CMB-S4 is a proposed experiment to map the polarization of the Cosmic Microwave Background (CMB) to nearly the cosmic variance limit for angular scales that are accessible from the ground. The science goals and capabilities of CMB-S4 in illuminating cosmic ... More
The Simons Observatory: Science goals and forecastsAug 22 2018Mar 01 2019The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. ... More
The Simons Observatory: Science goals and forecastsAug 22 2018The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. ... More