34 research outputs found
TURBO: The Swiss Knife of Auto-Encoders
We present a novel information-theoretic framework, termed as TURBO, designed
to systematically analyse and generalise auto-encoding methods. We start by
examining the principles of information bottleneck and bottleneck-based
networks in the auto-encoding setting and identifying their inherent
limitations, which become more prominent for data with multiple relevant,
physics-related representations. The TURBO framework is then introduced,
providing a comprehensive derivation of its core concept consisting of the
maximisation of mutual information between various data representations
expressed in two directions reflecting the information flows. We illustrate
that numerous prevalent neural network models are encompassed within this
framework. The paper underscores the insufficiency of the information
bottleneck concept in elucidating all such models, thereby establishing TURBO
as a preferable theoretical reference. The introduction of TURBO contributes to
a richer understanding of data representation and the structure of neural
network models, enabling more efficient and versatile applications
Anomaly localization for copy detection patterns through print estimations
Copy detection patterns (CDP) are recent technologies for protecting products
from counterfeiting. However, in contrast to traditional copy fakes, deep
learning-based fakes have shown to be hardly distinguishable from originals by
traditional authentication systems. Systems based on classical supervised
learning and digital templates assume knowledge of fake CDP at training time
and cannot generalize to unseen types of fakes. Authentication based on printed
copies of originals is an alternative that yields better results even for
unseen fakes and simple authentication metrics but comes at the impractical
cost of acquisition and storage of printed copies. In this work, to overcome
these shortcomings, we design a machine learning (ML) based authentication
system that only requires digital templates and printed original CDP for
training, whereas authentication is based solely on digital templates, which
are used to estimate original printed codes. The obtained results show that the
proposed system can efficiently authenticate original and detect fake CDP by
accurately locating the anomalies in the fake CDP. The empirical evaluation of
the authentication system under investigation is performed on the original and
ML-based fakes CDP printed on two industrial printers
MuSR method and tomographic probability representation of spin states
Muon spin rotation/relaxation/resonance (MuSR) technique for studying matter
structures is considered by means of a recently introduced probability
representation of quantum spin states. A relation between experimental MuSR
histograms and muon spin tomograms is established. Time evolution of muonium,
anomalous muonium, and a muonium-like system is studied in the tomographic
representation. Entanglement phenomenon of a bipartite muon-electron system is
investigated via tomographic analogues of Bell number and positive partial
transpose (PPT) criterion. Reconstruction of the muon-electron spin state as
well as the total spin tomography of composed system is discussed.Comment: 20 pages, 4 figures, LaTeX, submitted to Journal of Russian Laser
Researc
Calculation of clamping error when mounting a workpiece on fixture supports
This article examines the conditions for reliable clamping of workpieces in fixtures, which are one of the main elements in a technological system. In order to calculate clamping error of workpieces in fixtures empirical relationships of nonlinear character are currently used. Values of the coefficients included in these relationships are only specified for steel or cast iron workpieces. The paper presents the technique for calculating the clamping error of workpieces mounted on fixture supports with spherical heads, which allow to achieve the greatest locating precision. Practically, this technique allows to perform the calculation of the specified error for different fixturing conditions of workpieces. Mathematical relationships for calculation of the error for machining workpieces of any modern engineering materials are obtained. Comparative analysis of the obtained relationships for the standard conditions of force contact of the support elements with the workpiece showed that the clamping error calculated in accordance with the obtained relationships and taking into account friction forces in the contact area of the supports with the surface of steel workpiece almost coincides with the error determined by formulas given in the reference literuture. It is demonstrated that with the decrease in clamping force the elastic displacements at the interface are negligible and the clamping error can be calculated through a simplified relationship
ANALYSIS CONDITIONS FOR RELIABLE ATTACH OF WORKPIECES DURING LATHE MACHINING ON THE MASHINES WITH NUMERICAL SOFT-WARE CONTROL
In the article the conditions are properly secured work pieces when turning on CNC machines. The mathematical expressions that guarantee no damage while fixing in the chuck work pieces of ductile and brittle materials. Expressions allow determining the minimum length of the fastening pieces in the cartridge for these materials, as well as for the calculation of permissible cutting forces. It is shown that by adjusting the processing conditions may prevent damage to the work piece surfaces at the impossibility of changing their length in the fixing chuck
Evolution in Time of Radiation Defects Induced by Negative Pions and Muons in Crystals with a Diamond Structure
Evolution in time of radiation defects induced by negatively-charged pions and muons in crystals with diamond structures is considered. Negative pions and muons are captured by the nucleus and ionize an appropriate host atom, forming a positively-charged radiation defect in a lattice. As a result of an evolution in time, this radiation defect transforms into the acceptor center. An analysis of the full evolution process is considered for the first time. Formation of this acceptor center can be divided into three stages. At the first stage, the radiation defect interacts with a radiation trace and captures electrons. The radiation defect is neutralized completely in Si and Ge for a short time t †10 â 11 s, but in diamond, the complete neutralization time is very large t â„ 10 â 6 s. At the second stage, broken chemical bonds of the radiation defect are restored. In Si and Ge, this process takes place for the neutral radiation defect, but in diamond, it goes for a positively-charged state. The characteristic time of this stage is t < 10 â 8 s for Si and Ge and t < 10 â 11 s for diamond. After the chemical bondsâ restoration, the positively-charged, but chemically-bound radiation defect in diamond is quickly neutralized because of the electron density redistribution. The neutralization process is characterized by the lattice relaxation time. At the third stage, a neutral chemically-bound radiation defect captures an additional electron to saturate all chemical bonds and forms an ionized acceptor center. The existence of a sufficiently big electric dipolar moment leads to the electron capture. Qualitative estimates for the time of this process were obtained for diamond, silicon and germanium crystals. It was sown that this time is the shortest for diamond (†10 â 8 s) and the longest for silicon (†10 â 7 s
THEORETICAL PROBLEMS ON STUDY OF CONDENSATED MEDIA BY MUON METHOD
The work is concerned with the polarization behaviour of the muon spin in the substance. The aim is to develop the theory of the muon method for investigation of the substance, to construct the theory explaining the experimental results and to stimulate the formulation of the new experiments. The interactions of the muonium atom in the crystals with structure of the diamond and zinc blende have been firstly taken into consideration in details. The general problems on the depolarization of the muon spin in the muonium with anisotropic spin Hamiltonians has been solved. The general regularities of the muon spin polarization behaviour in the muonium formed in the metals have been obtained. The mesonic method theory bases for investigation of the De Haas-Van Alphen effect have been developed. The theory of the muon acoustic spin resonance has been developed. The theory of the muon spin polarization behaviour in the condensated phases of the hydrogen protons has been constructed.Available from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio