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This paper presents the results of a study of the structural and optical properties of arrays of (111)-oriented GaP nanowires (NWs) and single NWs using Raman spectroscopy and atomic force microscopy (AFM). GaP NW arrays are grown on a (111)-Si substrate by self-catalytic growth via the vapor-liquid-crystal mechanism. Single GaP NWs are mechanically transferred onto a gold surface. Transverse (TO), longitudinal (LO), and surface (SO) optical phonon modes are observed in the Raman spectra of GaP NWs. Surface-enhanced Raman scattering by optical phonon modes in GaP NWs near a gallium droplet is detected, due to the localized surface plasmon resonance in the droplet. Raman maps for GaP NWs recorded on various scattering geometries are obtained. The Raman enhancement factor for GaP NWs with a diameter of 104 and 60 nm reaches values of ~11 and 6, respectively.

The paper presents the results of a study of scanning irregularity in an optical interference microscope, performed both by a micrometer stage and a piezoceramic actuator. Registration of interference during the scanning process was carried out with a high-speed digital video camera, which allowed us to register the interference signal in detail. The obtained scanning results show the non-uniformity of the distances between adjacent interference fringes along the reference axis ─ the frame number. The procedure is presented that significantly decrease the value of non-uniformity. Application of such procedure allows to form a metric scale along scanning axis which can be used at performing high accuracy interference measurements of surface microrelief.

The paper presents results of identification of acoustic emission signatures of processes occurring during direct laser melting. As part of the experimental study, samples from the powder alloy EP 648 are grown in various modes with simultaneous recording of acoustic emission signals. Based on the results of the analysis of the registered signals parameters, their characteristic distribution patterns are formed during laser melting of defect-free and defective samples.

This paper proposes solutions that increase the efficiency of parallel program execution on high-performance computing systems when simulating heteroepitaxial growth on multiprocessor systems with shared memory. The developed algorithms are oriented towards the execution of program implementation of simulation of heteroepitaxial growth on multiprocessor NUMA nodes with shared memory. The primary prerequisite for the effective execution of parallel programs on the resources of a multiprocessor node is the incorporation of an architectural approach to the implementation of algorithms for data transfer through the shared memory of NUMA nodes. The proposed algorithms for optimizing synchronization in shared memory systems enhance the efficiency of accessing the shared memory of a multiprocessor node and reduce the time required for barrier synchronization. The developed methods and algorithms are implemented in the form of software for multiprocessor NUMA nodes with shared memory.

For spaces of object representations with given distances, the lower bounds to the error probability of object classification subject to the fixed values of the amount of processed information are investigated. The bounds are defined by the strictly decreasing functions of the minimal average mutual information between the submitted objects and the estimations of their classes depending on the error probability. So, the inverse functions yield the minimal error probability for any fixed value of the average mutual information. For spaces of tree-structured and vector-based object representations, numerical realizations of the bounds are calculated. It is shown that the lower bound to the error probability is lower in the space of vector-based representations as against the similar bound in the space of tree-structured representations. Also, a possibility of decreasing the bound to the error probability by combining object representations with various distance functions is demonstrated.

This work proposes new algorithms for combining superpixels into segments using a “greedy” strategy and a combined quality measure that includes two components: a measure of information redundancy and variation of information. The “greedy” strategy was previously used by the author to speed up image segmentation from the condition of minimum information redundancy, and a two-component information quality measure was used in the problem of combining different segmentation maps. The joint use of the “greedy” strategy and the combined quality measure in new algorithms is aimed at accelerating the generation of segmentation maps and improving their quality through a compromise between the requirements of minimizing the number of informationally important segments and minimizing the information difference between the original images and the generated partitions. A computational experiment on test images shows that the proposed algorithms can speed up the segmentation process compared to the method based on minimizing information redundancy previously used by the author and improve the information characteristics of the resulting segmentation maps.

The paper proposes a method for protecting 3D printed products made using the FDM technology from unauthorized copying. This method is based on the controlled deviation of the trajectory of filament application on a flat section of the surface layer of the product. The amount of deviation of the line trajectory is determined by the built-in security mark, which plays the role of a watermark. Changes made in this way are difficult to detect visually and even more difficult to automatically read when scanning the shape of a 3D product and subsequently reproduce it when creating its copy. In this case, verification of the authenticity of a product by detecting a security mark can be performed by shooting the product with a digital camera and specialized processing based on spectral analysis and narrow-band filtering.

Experiments are conducted on the use of mathematical processing methods for an expanded comparative analysis of the composition of biomaterials and brefomatrices. The linear discriminant analysis and ROC analysis are used as the main mathematical methods for processing the Raman spectra of the biomaterials under study. It is found that demineralized biomaterials from juvenile dentin are less antigenic compared to brefomatrices.

The work is devoted to studying the possibility of increasing the accuracy of measuring the coordinates and brightness of small-sized moving objects in a sequence of images formed by a scanning multi-row photodetector. The measurement is based on approximating the object image with a function whose parameters are the object brightness and the shift of its projection center relative to the nodes of the array of photosensitive cells (PSC) of the receiver. The approximation quality criteria are, on the one hand, the root-mean-square difference between the object image and the approximating function, and on the other hand, the spread of its coordinates and brightness estimates depending on the position relative to the center of the photodetector cell in a series of images. Several of the most popular functions commonly used to approximate a discrete image of a small-sized object are compared on a series of images obtained by projecting an illuminated small-diameter diaphragm into the plane of the photosensitive layer of the receiver. It is shown that, even with a sufficiently high level of random noise, the use of an approximating model allows one to estimate the coordinates of an object with a root-mean-square error not exceeding 20% of the PSC lattice step.

The article proposes a technique to identify the location of the round-shaped object in the image and to calculate its diameter. The technique is based on calculating the cross-correlation values of the analyzed image and several specific pattern images and on the subsequent analysis which of the patterns and for what its position relative to the inspected image is the most suitable one. The technique allows one not only to calculate the object size and coordinates, but also to determine the actual presence or absence of the object in the field of view. The feasibility and practical applicability of the technique are shown using an example of inspecting the ball-type wire bonding to the surface of a die in integrated circuits. The algorithm can be used as a part of software for non-destructive testing systems intended to inspect semiconductor products during their manufacturing before casing them. In particular, the algorithm allows one to check if there is a ball-type wire bonding at the place where it should be and to determine if both the location of the ball and its diameter are acceptable.