圣彼得堡国立电子科技大学

Knowledge graph completion (KGC) is crucial for enhancing the predictive capabilities of knowledge graphs (KGs) by inferring missing links and entities. In such domains as telecommunications, where business processes are highly interconnected, an effective KGC model can serve as a recommendation system for business analysts, aiding in process optimization. This paper proposes a transformer-based multi-hop reasoning model for KGC, trained on a telecommunications KG structured according to the models provided by TM Forum consortium that is a global industry association for service providers and their suppliers in the telecommunications industry. The model leverages relational paths and semantic dependencies within a sequence-to-sequence architecture to predict new connections and generate interpretable reasoning paths. To address the scarcity of real-world data, a novel method for generating synthetic telecommunications KGs with controlled structural variations is introduced. Experimental results demonstrate the model’s robustness and superior performance compared to traditional embedding-based methods, particularly in noisy environments, while providing actionable insights for business analysts. The work bridges the gap between KGC and practical recommendation systems, highlighting the value of interpretable multi-hop reasoning in telecommunications business process optimization.

Introduction. Polyvinyl alcohol (PVA) films are widely used in flexible electronics, biosensors, and liquid-crystal optical elements. Like many polymer materials, these films exhibit relatively low mechanical strength, which often necessitates additional protective layers that may reduce the efficiency of electronic and optical components. Sensitization with various nanoparticles is a well-established strategy for tuning the physical and chemical properties of polymer systems. In this study, shungite nanoparticles were selected as a sensitizer, as this natural, nontoxic carboncontaining material is known to enhance mechanical strength. Aim. To obtain PVA films sensitized with shungite nanoparticles; to investigate their spectral and mechanical characteristics as functions of synthesis parameters; and to identify processing conditions that provide an optimal balance between optical performance and mechanical stability. Materials and methods. Films were synthesized using the method developed at the S. I. Vavilov State Optical Institute. PVA served as the polymer matrix, and Karelian shungite nanoparticles containing 30 % carbon were introduced as a filler. Spectral characteristics were measured with a UV-3200 spectrophotometer, and mechanical properties were evaluated using a PMT-3M microhardness tester (LOMO). Results. The films exhibited a polarization degree exceeding 90 % across the visible spectral range without additional lamination. Incorporation of shungite nanoparticles increased the mechanical strength of PVA films by up to 1.6-fold. Conclusion. Modern photonic devices require materials that combine high polarization efficiency and optical transmittance with mechanical robustness. The developed approach strengthens PVA polarizing films while preserving their optical properties, thereby expanding current understanding of mechanical-property control in nanocomposite systems.

Erasure-coded storage systems adopt multiple redundancy levels to balance reliability and storage efficiency under changing workloads. However, transitioning data across different redundancy configurations incurs high network overhead due to data relocation and parity recomputation, especially under successive transitions. Existing approaches are typically optimized for fixed parameters and lack flexibility and scalability. This article presents FlexRT , a flexible and efficient redundancy transitioning framework for erasure-coded systems. FlexRT employs a linear-hashing–based stripe placement that decouples stripe layout from coding parameters, enabling zero data relocation across successive transitions. To minimize parity update overhead, FlexRT binds encoding coefficients to physical nodes instead of logical stripe positions, allowing parity to be incrementally updated even when data blocks are reorganized. In addition, a greedy sub-stripe decomposition and matching algorithm maximizes parity reuse and reduces the amount of data involved in recomputation, transforming redundancy transitioning into an efficient split-and-merge process. We implement FlexRT in a C++ prototype and evaluate it through large-scale simulations and Alibaba Cloud experiments. Results show that FlexRT reduces transitioning traffic by 86.0%–94.1% and shortens transition time by 79.4%–89.2% compared with state-of-the-art schemes, while completely eliminating data relocation.

This paper presents a new type of ultrasonic gyroscopic sensor based on a solid-state standing-wave vibrator, which is promising for shock-resistant applications. A theoretical model of the proposed design, which is a layered structure, and the numerical simulation of its frequency response using the developed software are presented. A test sample of the novel sensing element was made and experimental studies of its frequency response were conducted. The results showed a high correlation between the resonant frequencies both for the real sample research and numerical modeling; thus, the validity of the theoretical model was confirmed. The laboratory investigation of the developed sensing element on a test bench under rotating conditions was carried out and a shift in the standing-wave amplitude proportional to the angular velocity of rotation was revealed; thus, an informative signal for this type of gyroscopic sensor was found. It is shown that the amplitude of the output signal of the new sensor on standing waves compares favorably with the signal levels reported for similar traveling-wave solutions in previous studies. The optimization strategies for the new sensor’s design and operating mode to increase signal to noise ratio are also identified. Thus, the potential of using the developed solid-state standing-wave vibrator as a shock-resistant ultrasonic gyroscopic sensor is supported.

Purpose of the work. Conducting a comprehensive study to determine the optimal shape of the piezoelectric transducer damper, from the point of view of minimizing parasitic signals. Materials and methods. The efficiency of employing dampers with diverse geometries was assessed through computational analysis employing the finite element method, which was then validated against experimental findings. Results. A research on the efficiency of different types of dampers, including a truncated cylinder and a fully truncated cylinder, is presented. To achieve this, the model developed in the initial phase of the study was further refined and applied to calculate the shapes of the dampers other than the truncated cone. The analysis of ultrasonic wavefronts within the body of the damper is performed to identify the source of minor signal fluctuations in the case of a fully truncated cylinder-shaped damper. Conclusion. The theoretical framework outlined in the initial section of this paper has been successfully implemented to assess the performance of different shapes of dampers. The analysis of the data yielded insights into the most efficient design for minimizing the amplitude of the unwanted signal. A satisfactory degree of consistency was observed across the various approaches employed.