A Reconfiguration Algorithm for the Single-Driven Hexapod-Type Parallel Mechanism

This paper presents a hexapod-type reconfigurable parallel mechanism that operates from a single actuator. The mechanism design allows reproducing diverse output link trajectories without using additional actuators. The paper provides the kinematic analysis where the analytical relationships between the output link coordinates and actuated movement are determined. These relations are used next to develop an original and computationally effective algorithm for the reconfiguration procedure. The algorithm enables selecting mechanism parameters to realize a specific output link trajectory. Several examples demonstrate the implementation of the proposed techniques. CAD simulations on a mechanism virtual prototype verify the correctness of the suggested algorithm.

Conjugate gradient algorithm for consistent generalized Sylvester-transpose matrix equations

<abstract><p>We develop an effective algorithm to find a well-approximate solution of a generalized Sylvester-transpose matrix equation where all coefficient matrices and an unknown matrix are rectangular. The algorithm aims to construct a finite sequence of approximated solutions from any given initial matrix. It turns out that the associated residual matrices are orthogonal, and thus, the desire solution comes out in the final step with a satisfactory error. We provide numerical experiments to show the capability and performance of the algorithm.</p></abstract>

T2FRF Filter: An Effective Algorithm for the Restoration of Fingerprint Images

Images captured in dim light are hardly satisfactory and increasing the International Organization for Standardization (ISO) for a short duration of exposure makes them noisy. The image restoration methods have a wide range of applications in the field of medical imaging, computer vision, remote sensing, and graphic design. Although the use of flash improves the lighting, it changed the image tone besides developing unnecessary highlight and shadow. Thus, these drawbacks are overcome using the image restoration methods that recovered the image with high quality from the degraded observation. The main challenge in the image restoration approach is recovering the degraded image contaminated with the noise. In this research, an effective algorithm, named T2FRF filter, is developed for the restoration of the image. The noisy pixel is identified from the input fingerprint image using Deep Convolutional Neural Network (Deep CNN), which is trained using the neighboring pixels. The Rider Optimization Algorithm (ROA) is used for the removal of the noisy pixel in the image. The enhancement of the pixel is performed using the type II fuzzy system. The developed T2FRF filter is measured using the metrics, such as correlation coefficient and Peak Signal to Noise Ratio (PSNR) for evaluating the performance. When compared with the existing image restoration method, the developed method obtained a maximum correlation coefficient of 0.7504 and a maximum PSNR of 28.2467dB, respectively.

Revealing of the specificity of mortgage housing lending based on the results of clustering of regions

Subject. This article deals with the particularities of the development of housing mortgage lending in the regions of Russia. Objectives. The article aims to substantiate the need for clustering of territorial entities by level of development of mortgage housing lending in Russia and test the most effective algorithm for mortgage clustering of regions. Methods. For the study, we used a systems approach, including scientific abstraction, analysis and synthesis, and statistical methods of data analysis. The algorithm k-medoids – Partitioning Around Medoids (PAM) was also used. Results. Based on the results of the study of regional statistics of the Russian Federation, the article reveals a significant asymmetry in the values of key socioeconomic indices that determine the level and dynamics of housing mortgages in the regions. This necessitates the clustering of territorial entities according to the level of development of mortgage housing lending in the country. To take into account the impact of various local conditions in assessing the prospects for the development of regional housing mortgages, the article proposes an indicator, namely, the integral regional mortgage affordability index. On its basis, in accordance with the selected clustering procedure, the article identifies five mortgage clusters in Russia and identifies their representative regions. Conclusions. Based on the analysis of the specificity of the development of regional mortgages in the Tula Oblast, taking into account the implementation of the target State programme, the article concludes that it is necessary to improve the mechanisms for financing regional mortgage programmes and justifies the need to develop differentiated programmes for the development of housing mortgages in groups of Russian regions.

The Dantzig selector: recovery of signal via ℓ 1 − αℓ 2 minimization

In the paper, we proposed the Dantzig selector based on the ℓ 1 − αℓ 2 (0 < α ⩽ 1) minimization for the signal recovery. In the Dantzig selector, the constraint ‖ A ⊤ ( b − Ax )‖∞ ⩽ η for some small constant η > 0 means the columns of A has very weakly correlated with the error vector e = Ax − b . First, recovery guarantees based on the restricted isometry property are established for signals. Next, we propose the effective algorithm to solve the proposed Dantzig selector. Last, we illustrate the proposed model and algorithm by extensive numerical experiments for the recovery of signals in the cases of Gaussian, impulsive and uniform noises. And the performance of the proposed Dantzig selector is better than that of the existing methods.

Compensation Gyrocompass Based on MEMS

The study of an astatic compensating gyrocompass, built on the basis of a modulation micromechanical gyroscope (MMG) of a hybrid type, has been carried out. A kinematic diagram is given and the principle of operation of the device has describing. The device uses the modulation principle based on obtaining information about the angular motion of the rotor and creating control torques in a rotating coordinate system, which makes it possible to exclude such a significant disadvantage of MMG as "zero offset". A feature of the gyrocompass under consideration is the use of two channels for controlling the rotor of the MMG, namely: a channel for the formation of a guiding moment, striving to combine its main axis with the direction of the true meridian and a channel for compensating this guiding moment. A linearized mathematical model has building, on the base of which an effective algorithm for the operation of a compensatory astatic gyrocompass is proposed. The device under consideration can be used to determine the true azimuth of the longitudinal axis of a mobile ground object, it has a higher measurement speed compared to devices built on three-degree "heavy" gyroscopes, and has good resistance to external influences (vibrations, shocks, etc.).