Search results for "metrology"
showing 10 items of 96 documents
Symmetric logarithmic derivative of Fermionic Gaussian states
2018
In this article we derive a closed form expression for the symmetric logarithmic derivative of Fermionic Gaussian states. This provides a direct way of computing the quantum Fisher Information for Fermionic Gaussian states. Applications ranges from quantum Metrology with thermal states and non-equilibrium steady states with Fermionic many-body systems.
Hyperspectral Texture Metrology Based on Joint Probability of Spectral and Spatial Distribution
2021
International audience; Texture characterization from the metrological point of view is addressed in order to establish a physically relevant and directly interpretable feature. In this regard, a generic formulation is proposed to simultaneously capture the spectral and spatial complexity in hyperspectral images. The feature, named relative spectral difference occurrence matrix (RSDOM) is thus constructed in a multireference, multidirectional, and multiscale context. As validation, its performance is assessed in three versatile tasks. In texture classification on HyTexiLa, content-based image retrieval (CBIR) on ICONES-HSI, and land cover classification on Salinas, RSDOM registers 98.5% acc…
Roadmap on quantum nanotechnologies
2021
Quantum phenomena are typically observable at length and time scales smaller than those of our everyday experience, often involving individual particles or excitations. The past few decades have seen a revolution in the ability to structure matter at the nanoscale, and experiments at the single particle level have become commonplace. This has opened wide new avenues for exploring and harnessing quantum mechanical effects in condensed matter. These quantum phenomena, in turn, have the potential to revolutionize the way we communicate, compute and probe the nanoscale world. Here, we review developments in key areas of quantum research in light of the nanotechnologies that enable them, with a …
Surface Integrity
2008
This chapter provides comprehensive knowledge regarding the state and properties of both surface and subsurface layers generated during machining processes, including different associated mechanical and thermal influences. Basic models of the superficial layer and factors effecting surface integrity are presented. Decomposition of surface topography into roughness, waviness and form along with appropriate filtering methods is outlined. The characterization of surface roughness based on 2D and 3D roughness parameters as well as motif, fractal and frequency characteristics are presented. In particular, all standardized areal surface parameters are specified, and practical examples are provide…
High Voltage Metrology with Collinear Laser Spectroscopy
2018
We present results of laser spectroscopic high voltage measurements on the 5 ppm relative uncertainty level using a pump and probe scheme on Ca+ ions. With the two-stage laser interaction and with a reference measurement we can eliminate systematic effects like differences in contact potentials of electrode materials, thermo-electric voltages, and the unknown starting potential of the ions in the ion source. Our measurements are compatible with the 5 ppm precision limits of the high voltage dividers used for comparison and demonstrate an unprecedented increase in the accuracy of laser-based high voltage measurements by a factor of 20.
Projected fringes for the measurement of large aluminum ingots
2010
The method of projected fringes is applied to the measurement of the surface topography of aluminum ingots with surface areas of several square meters. The measurements are performed inside the casting hall of an aluminum factory. To meet the challenges encountered in such a demanding environment, it is important to keep the equipment as simple and robust as possible. Therefore a method for locating the fringe positions with sub-pixel accuracy without using for example phase shifting techniques is applied. Also the nonlinearity of the phase when using divergent illumination is discussed. The developed measuring system is tested measuring eight different aluminum ingots, and the results agre…
Краткое обозрѣніе системы мѣръ и денегъ въ Китаѣ
1909
Отдельный оттиск из 2-го выпуска XXIX тома Известий Восточного Института
Micro-Machining
2017
This chapter provides comprehensive knowledge regarding the fabrication of micro-products and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques such as micro-machining and new trends in improving micro-processes taking into account EDM, laser, FIB, LIGA and DRIE processes are overviewed. The background of micro-machining processes, including typical machining operations such as turning, milling and drilling and different construction materials, is outlined. Moreover, a special focus was made on new constructions, control systems and effective applications of micro-machining techniques. In addition, the focus was directed towa…
Nanomanufacturing/Nanotechnology
2017
This chapter provides comprehensive knowledge regarding the fabrication of nanoproducts and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques, such as nanomachining (ultra-precision) and new trends in improving nanoprocesses taking into account AFM, laser beam machining, electron beam machining processes are overviewed. The background of nanomachining processes, including typical machining operations such as turning, milling and grinding and different construction materials (metallic and nonmetallic), is outlined. The physical mechanisms responsible for the transition from brittle to ductile regime machining are explained. Mo…
Geometric quality and appearance of surfaces : local and global approaches
2012
Accounting for customers' perception of manufactured goods has become a major challenge for the industry. This process is to be established from early design to retail. Customers are nowadays more aware and detail oriented about perceived quality of products. This allows one to set not only an estimated price but also the expected quality of the product. Surface appearance analysis has therefore become a key industrial issue. Two approaches are proposed here to formalize the detection methodology and provide objective criteria for experts to evaluate surface anomalies. The first proposed approach is based on surface metrology. It consists in analyzing the measured topologies in order to bin…