1,379 research outputs found
The algorithm for automatic detection of the calibration object
The problem of the automatic image calibration is considered in this paper. The most challenging task of the automatic calibration is a proper detection of the calibration object. The solving of this problem required the appliance of the methods and algorithms of the digital image processing, such as morphology, filtering, edge detection, shape approximation. The step-by-step process of the development of the algorithm and its adopting to the specific conditions of the log cuts in the image's background is presented. Testing of the automatic calibration module was carrying out under the conditions of the production process of the logging enterprise. Through the tests the average possibility of the automatic isolating of the calibration object is 86.1% in the absence of the type 1 errors. The algorithm was implemented in the automatic calibration module within the mobile software for the log deck volume measurement. © 2017 Author(s)
First-Principles Prediction of Electronic Transport in Experimental Semiconductor Heterostructures via Physics-Based Machine Learning
First-principles techniques for electronic transport property prediction have
seen rapid progress in recent years. However, it remains a challenge to model
heterostructures incorporating variability due to fabrication processes.
Machine-learning (ML)-based materials informatics approaches (MI) are
increasingly used to accelerate design and discovery of new materials with
targeted properties, and extend the applicability of first-principles
techniques to larger systems. However, few studies exploited MI to learn
electronic structure properties and use the knowledge to predict the respective
transport coefficients. In this work, we propose an
electronic-transport-informatics (ETI) framework that trains on ab initio
models of small systems and predicts thermopower of silicon/germanium
heterostructures beyond the length-scale accessible with first-principles
techniques, matching measured data. We demonstrate application of MI to extract
important physics that determines electronic transport in semiconductor
heterostructures, breaking from combinatorial strategies pursued especially for
thermoelectric materials. We anticipate that ETI would have broad applicability
to diverse materials classes.Comment: 14 pages, 7 figure
Transfer-matrix calculations of the effects of tension and torque constraints on DNA-protein interactions
Organization and maintenance of the chromosomal DNA in living cells strongly
depends on the DNA interactions with a plethora of DNA-binding proteins.
Single-molecule studies show that formation of nucleoprotein complexes on DNA
by such proteins is frequently subject to force and torque constraints applied
to the DNA. Although the existing experimental techniques allow to exert these
type of mechanical constraints on individual DNA biopolymers, their exact
effects in regulation of DNA-protein interactions are still not completely
understood due to the lack of systematic theoretical methods able to
efficiently interpret complex experimental observations. To fill this gap, we
have developed a general theoretical framework based on the transfer-matrix
calculations that can be used to accurately describe behaviour of DNA-protein
interactions under force and torque constraints. Potential applications of the
constructed theoretical approach are demonstrated by predicting how these
constraints affect the DNA-binding properties of different types of
architectural proteins. Obtained results provide important insights into
potential physiological functions of mechanical forces in the chromosomal DNA
organization by architectural proteins as well as into single-DNA manipulation
studies of DNA-protein interactions.Comment: 61 pages, including 14 figures and 2 table
Interaction broadening of Wannier functions and Mott transitions in atomic BEC
Superfluid to Mott-insulator transitions in atomic BEC in optical lattices
are investigated for the case of number of atoms per site larger than one. To
account for mean field repulsion between the atoms in each well, we construct
an orthogonal set of Wannier functions. The resulting hopping amplitude and
on-site interaction may be substantially different from those calculated with
single-atom Wannier functions. As illustrations of the approach we consider
lattices of various dimensionality and different mean occupations. We find that
in three-dimensional optical lattices the correction to the critical lattice
depth is significant to be measured experimentally even for small number of
atoms. Finally, we discuss validity of the single band model.Comment: A co-author(AMD) added, paper lengthened (7 pages, 8 figures now) to
extend the description of the method and add discussion of its validit
Estimation of the physico-chemical parameters of materials based on rare earth elements with the application of computational model
Computational model, technique and the basic principles of operation program complex for quantum-chemical calculations of material's physico-chemical parameters with rare earth elements are discussed. The calculating system is scalable and includes CPU and GPU computational resources. Control and operation of computational jobs and also Globus Toolkit 5 software provides the possibility to join computer users in a unified system of data processing with peer-to-peer architecture. CUDA software is used to integrate graphic processors into calculation system
Berry phase of spin-one system in a rotating electric field
We consider in sufficient detail how the Berry phase arises in a rotating
electric field in a model system with spin one. The goal is to help the student
who first encountered this interesting problem, which is fraught with some
subtleties that require attention in order not to go astray.Comment: 10 pages, no figure
Mapping solar array location, size, and capacity using deep learning and overhead imagery
The effective integration of distributed solar photovoltaic (PV) arrays into
existing power grids will require access to high quality data; the location,
power capacity, and energy generation of individual solar PV installations.
Unfortunately, existing methods for obtaining this data are limited in their
spatial resolution and completeness. We propose a general framework for
accurately and cheaply mapping individual PV arrays, and their capacities, over
large geographic areas. At the core of this approach is a deep learning
algorithm called SolarMapper - which we make publicly available - that can
automatically map PV arrays in high resolution overhead imagery. We estimate
the performance of SolarMapper on a large dataset of overhead imagery across
three US cities in California. We also describe a procedure for deploying
SolarMapper to new geographic regions, so that it can be utilized by others. We
demonstrate the effectiveness of the proposed deployment procedure by using it
to map solar arrays across the entire US state of Connecticut (CT). Using these
results, we demonstrate that we achieve highly accurate estimates of total
installed PV capacity within each of CT's 168 municipal regions
Analytical and micromagnetic study of a Neel domain wall
Journals published by the American Physical Society can be found at http://journals.aps.org/For ferromagnets with exchange, dipolar interaction, and uniaxial anisotropy, by both analytic methods and micromagnetic simulations we study Neel domain walls in thin ferromagnetic strips of finite width. Comparison of the numerical results with the analytics yields parameter values that had been unspecified by the analytics, and determines the modifications needed to describe the magnetization both near the strip center and near the boundaries. With no uniaxial anisotropy, the domain wall center can be described by the same hyperbolic secant form as with uniaxial anisotropy, but the effective anisotropy constant must now be thought of as increasing with increasing film thickness and decreasing with increasing film width
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