Flux pinning in high-Tc superconductive films

Magnetization measurements have been performed onc-axis oriented Y- and Gd-based superconductive films in a wide range of the temperaturesT (4.2–85 K) and magnetic fieldsH (0–8 T) withH c-axis. The influence of flux creep on both the temperature dependence of critical current densityJ _cm and the scaling behavior of flux pinning forceF _p has been discussed in detail. The experimental results show that Y and Gd films have different pinning mechanism. Flux pinning-force peaks in high fields are observed in Gd film at high temperatures and can be considered as evidence for collective pinning.     

Picosecond thermal pulses in thin gold films

In this paper it has been shown that, with the advent of lasers with a very short pulse duration, the effect of thermal wave propagation becomes important. To consider this effect, hyperbolic heat conduction in thin gold films was studied. It was shown that for heat fluxes of the order 10⁸ W·cm^–2, a thermal wave is generated in thin gold films. The consideration of the hyperbolicity of heat transfer enables one to describe the temperature profile with one value of fluence.     

State and prospects of inhibitor protection of the metal resources of the Ukraine

At present, the overall losses caused by corrosion in the Ukraine are very high and increase constantly owing to an increase in the aggressiveness of the environment and a lack of corrosion-resistant materials and anticorrosion technologies. The corrosion-mechanical fracture of metals (corrosion fatigue or corrosion cracking) proves to be the most dangerous type of corrosion since it occurs without visible changes in the appearance of structures. This is true, first of all, for pipelines, chemical and power equipment, municipal utility services, etc.The Ukrainian Association of Corrosionists has recently been founded with the aim of intensifying anticorrosion activities. The Association has about 40 organizational members (including academic and specialized institutes and industrial enterprises) and about one hundred individual members—prominent experts in corrosion science. The Technical Committee TC-85 Corrosion of Metals and Alloys was founded by the State Committee on Standardization and Metrology of the Ukraine. In 1993, the Ukraine became a member of the International Corrosion Council.In view of the urgency of this problem, the Editorial Board of Fiziko-Khimicheskaya Mekhanika Materialov begins a series of survey, problem, and discussion papers devoted to the problem of protection of metals against corrosion. Scientists and experts are invited to discuss this and related problems in our journal. The present work opens the series. We consider and characterize the main groups of corrosion inhibitors used in industry and indicate their developers and producers. The addresses of the Collection and computer bank of corrosion inhibitors and inhibited materials are also presented.Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 30, No. 1, pp. 11–17, January–February, 1994.     

VA + Embeddings STAR: A State-of-the-Art Report on the Use of Embeddings in Visual Analytics

Over the past years, an increasing number of publications in information visualization, especially within the field of visual analytics, have mentioned the term “embedding” when describing the computational approach. Within this context, embeddings are usually (relatively) low-dimensional, distributed representations of various data types (such as texts or graphs), and since they have proven to be extremely useful for a variety of data analysis tasks across various disciplines and fields, they have become widely used. Existing visualization approaches aim to either support exploration and interpretation of the embedding space through visual representation and interaction, or aim to use embeddings as part of the computational pipeline for addressing downstream analytical tasks. To the best of our knowledge, this is the first survey that takes a detailed look at embedding methods through the lens of visual analytics, and the purpose of our survey article is to provide a systematic overview of the state of the art within the emerging field of embedding visualization. We design a categorization scheme for our approach, analyze the current research frontier based on peer-reviewed publications, and discuss existing trends, challenges, and potential research directions for using embeddings in the context of visual analytics. Furthermore, we provide an interactive survey browser for the collected and categorized survey data, which currently includes 122 entries that appeared between 2007 and 2023.     

FSE2R: An Improved Collision-Avoidance-based Energy Efficient Route Selection Protocol in USN

The 3D Underwater Sensor Network (USNs) has become the most optimistic medium for tracking and monitoring underwater environment. Energy and collision are two most critical factors in USNs for both sparse and dense regions. Due to harsh ocean environment, it is a challenge to design a reliable energy efficient with collision free protocol. Diversity in link qualities may cause collision and frequent communication lead to energy loss; that effects the network performance. To overcome these challenges a novel protocol Forwarder Selection Energy Efficient Routing (FSE2R) is proposed. Our proposal’s key idea is based on computation of node distance from the sink, Residual Energy (RE) of each node and Signal to Interference Noise Ratio (SINR). The node distance from sink and RE is computed for reliable forwarder node selection and SINR is used for analysis of collision. The novel proposal compares with existing protocols like H2AB, DEEP, and E2LR to achieve Quality of Service (QoS) in terms of throughput, packet delivery ratio and energy consumption. The comparative analysis shows that FSE2R gives on an average 30% less energy consumption, 24.62% better PDR and 48.31% less end-to-end delay compared to other protocols.     

Secrecy Trade-off at the Physical Layer over Mixed Fading Multicast Channels Employing Antenna Diversity

This paper deals with the secrecy performance analysis of a multicast network over mixed fading scenarios in which a cluster of passive eavesdroppers is trying to overhear the secret transmission. Our key contribution is to prevent this malicious attack of the illegitimate receivers. Rayleigh/ Rician mixed fading channels are considered to model alternately the multicast/ eavesdropper and eavesdropper/ multicast channels as such mixed fading scenarios are often encountered in cellular communication where only one link (either multicast or eavesdropper) undergo a line-of-sight propagation path. At first, we derive the probability density functions for the single-input-multiple-output multicast scenarios and then the secrecy analysis is carried out by obtaining closed-form expressions for the performance matrices such as the probability of non-zero secrecy multicast capacity, ergodic secrecy multicast capacity, and secure outage probability for multicasting. The derived expressions are beneficial to investigate how the antenna diversity can combat the detrimental impact of fading as well as the number of multicast users and eavesdroppers, and improve the secrecy level to the acceptable limit. Moreover, the best secure scenario in terms of the secrecy parameters is obtained when the multicast channels undergo Rician fading whereas the eavesdropper channels experience Rayleigh fading. Finally, the analytical expressions are justified via the Monte-Carlo simulations.

     

Semi-Supervised Deep Learning for Multi-Tissue Segmentation from Multi-Contrast MRI

Journal of Signal Processing Systems - Segmentation of thigh tissues (muscle, fat, inter-muscular adipose tissue (IMAT), bone, and bone marrow) from magnetic resonance imaging (MRI) scans is useful...     

A hybrid method for variable-order fractional 2D optimal control problems on an unbounded domain

Engineering with Computers - In this study, the Caputo-Fabrizio fractional derivative is applied to generate a new category of variable-order fractional 2D optimization problems in an unbounded...