The preconditions of the export potential sublimating component origin in the modern companies activity

В сучасних умовах господарювання особливого змісту набувають суб’єктивні фактори впливу на розвиток експортного потенціалу підприємств. Серед них «рівень моральної стійкості і цілеспрямованості» і «сублімація експортного потенціалу».In modern conditions of managing special content become subjective factors influencing the development of export potential of enterprises. Among the factors "the level of moral fortitude and dedication, sublimation of export potential" are considered

Reviewing GPU architectures to build efficient back projection for parallel geometries

Back-Projection is the major algorithm in Computed Tomography to reconstruct images from a set of recorded projections. It is used for both fast analytical methods and high-quality iterative techniques. X-ray imaging facilities rely on Back-Projection to reconstruct internal structures in material samples and living organisms with high spatial and temporal resolution. Fast image reconstruction is also essential to track and control processes under study in real-time. In this article, we present efficient implementations of the Back-Projection algorithm for parallel hardware. We survey a range of parallel architectures presented by the major hardware vendors during the last 10 years. Similarities and differences between these architectures are analyzed and we highlight how specific features can be used to enhance the reconstruction performance. In particular, we build a performance model to find hardware hotspots and propose several optimizations to balance the load between texture engine, computational and special function units, as well as different types of memory maximizing the utilization of all GPU subsystems in parallel. We further show that targeting architecture-specific features allows one to boost the performance 2–7 times compared to the current state-of-the-art algorithms used in standard reconstructions codes. The suggested load-balancing approach is not limited to the back-projection but can be used as a general optimization strategy for implementing parallel algorithms

Recovering the second moment of the strain distribution from neutron Bragg edge data

Point by point strain scanning is often used to map the residual stress (strain) in engineering materials and components. However, the gauge volume and hence spatial resolution is limited by the beam defining apertures and can be anisotropic for very low and high diffraction (scattering) angles. Alternatively, wavelength resolved neutron transmission imaging has a potential to retrieve information tomographically about residual strain induced within materials through measurement in transmission of Bragg edges - crystallographic fingerprints whose locations and shapes depend on microstructure and strain distribution. In such a case the spatial resolution is determined by the geometrical blurring of the measurement setup and the detector point spread function. Mathematically, reconstruction of strain tensor field is described by the longitudinal ray transform; this transform has a non-trivial null-space, making direct inversion impossible. A combination of the longitudinal ray transform with physical constraints was used to reconstruct strain tensor fields in convex objects. To relax physical constraints and generalise reconstruction, a recently introduced concept of histogram tomography can be employed. Histogram tomography relies on our ability to resolve the distribution of strain in the beam direction, as we discuss in the paper. More specifically, Bragg edge strain tomography requires extraction of the second moment (variance about zero) of the strain distribution which has not yet been demonstrated in practice. In this paper we verify experimentally that the second moment can be reliably measured for a previously well characterised aluminium ring and plug sample. We compare experimental measurements against numerical calculation and further support our conclusions by rigorous uncertainty quantification of the estimated mean and variance of the strain distribution

Quantification and compensation of geometry-induced errors in cone-beam X-ray computed tomography

Since the industrial revolution, dimensional metrology has been tasked with meeting the continuously increasing demand for higher accuracy, faster and more comprehensive measuring techniques. X-ray Computed Tomography (CT) is a widely accepted non-destructive three-dimensional characterization technology which employs penetrating electromagnetic radiation and dedicated mathematical algorithms to visualize and analyze the internal structure of an object. While CT has shown significant potential for non-destructive coordinate measurements of external and internal features, there is a need for metrological research to accelerate the acceptance of CT as a measuring instrument. There is uncertainty in the result of any measurement. Uncertainty is an indication of the quality of a given measurement result and translates into the confidence with which a decision on part conformance can be made. Metrological standards demand that each source of error be determined, if possible, compensated, and residuals after compensation propagated to uncertainty in the measurement result. The major problems complicating characterization and compensation of error sources in CT dimensional measurements are an analytically intractable measurement model i.e. measurement model cannot be written as closed-form analytic expression) and high computational cost associated with simulation of the CT measurement procedure (time, memory and other resources). These problems highlight the need for a framework where uncertainty due to geometrical influence factors is addressed and managed in a computationally efficient way. In this thesis, a framework to handle geometry-induced errors for CT dimensional measurements is developed. The framework consists of three main parts: 1. a method for reducing influence of the Feldkamp artifacts, 2. a method for software-based compensation of misalignments in CT geometry, and 3. a computationally inexpensive model for estimating dimensional measurement uncertainty due to residual misalignments in the CT instrument geometry. Appearance of Feldkamp artifacts depends on the object itself and its position and orientation during data acquisition. The first method uses a meshed surface, e.g. a Computer-Aided Design (CAD) model of an object and its orientation in the measurement volume to predict where the object's surface will not be reconstructed properly due to Feldkamp artifacts. The method is applied to estimate the object position and orientation that reduces the effects of Feldkamp artifacts. The second part of the work investigates the capabilities of software-based compensation of CT instrument misalignments as an effective alternative to mechanical adjustment of a CT instrument. Quantitative and qualitative results from computer simulations and experimental study show that a modified conventional reconstruction algorithm with embedded misalignment compensation is an efficient and robust alternative to mechanical adjustment of a CT instrument. The third part of the proposed framework is a model for estimating dimensional measurement uncertainty due to CT instrument misalignments. The model uses surface points extracted from a CAD-model to calculate discrepancies in the radiographic image coordinates assigned to the projected edges from an aligned system and from a system with misalignments. The proposed method is designed to provide computational benefits in the assessment of coordinate measurement uncertainty when compared to a full Monte Carlo simulation of a CT measurement chain. The efficacy of the proposed method was confirmed on simulated and experimental data in the presence of various geometrical uncertainty contributors.status: publishe

THEORY OF PETRI NETS IN THE DEVELOPMENT AND MATHEMATICAL MODEL OF A SINGLE ARROW CONTROL BLOCKS

This article presents the results of simulation using Petri networks, operation of nodes of microprocessor set block control of single arrow system of railway automation and telemechanics

Recovering the second moment of the strain distribution from neutron Bragg edge data

Point by point strain scanning is often used to map the residual stress (strain) in engineering materials and components. However, the gauge volume and, hence, spatial resolution are limited by the beam defining apertures and can be anisotropic for very low and high diffraction (scattering) angles. Alternatively, wavelength resolved neutron transmission imaging has a potential to retrieve information tomographically about residual strain induced within materials through measurement in transmission of Bragg edges—crystallographic fingerprints whose locations and shapes depend on microstructure and strain distribution. In such a case, the spatial resolution is determined by the geometrical blurring of the measurement setup and the detector point spread function. Mathematically, reconstruction of the strain tensor field is described by the longitudinal ray transform; this transform has a non-trivial null-space, making direct inversion impossible. A combination of the longitudinal ray transform with physical constraints was used to reconstruct strain tensor fields in convex objects. To relax physical constraints and generalize reconstruction, a recently introduced concept of histogram tomography can be employed. Histogram tomography relies on our ability to resolve the distribution of strain in the beam direction, as we discuss in the paper. More specifically, Bragg edge strain tomography requires extraction of the second moment (variance about zero) of the strain distribution, which has not yet been demonstrated in practice. In this paper, we verify experimentally that the second moment can be reliably measured for a previously well characterized aluminum ring and plug sample. We compare experimental measurements against numerical calculation and further support our conclusions by rigorous uncertainty quantification of the estimated mean and variance of the strain distribution