bluuebunny/crossref_metadata_2025 huggingface dataset:
Resource Consumption Forecasting for Information System using Holt-Winters Method and Linear Regression Method
Authors: He Yunrui , Yiying-yan  , Yijie-dang  , Zhiyu-chen
Published: December 2020

Through the analysis of historical data and model training, the resource consumption forecasting of information system can estimate the utilization of resources in the future and help to make resource planning in advance. The traditional methods are usually based on the experience of operation and maintenance personnel and the preliminary statistics of subsequent plans, which is time-consuming and labor intensive, and cannot adapt to unplanned changes. In order to solve these issues, an automatic resource consumption forecasting method based on Holt-Winters and linear regression algorithm is proposed in this paper. The experimental results show that the method can well predict the periodic and incremental resource consumption changes.
Design of photovoltaic hot spot detection system based on deep learning
Authors: Ren Yifeng , Yu Yongjun , Li Jing , Zhang Wenhua
Published: December 2020

At present, it is difficult to detect the photovoltaic (PV) hot spots and the recognition efficiency is low. In this paper, an improved Single Shot MultiBox Detector (SSD) algorithm was designed for PV hot spot detection. The algorithm used the MobileNet network to replace the VGG16 convolutional neural network structure in the original SSD. This network is a depthwise separable convolution structure. Using it for feature extraction can reduce the number of parameters in the structure and achieve the purpose of speeding up the network. The experimental results show that the improved algorithm can detect the hot spots of PV array with good confidence, low detection rate and good robustness. Compared with the You Only Look Once(YOLO) algorithm and the original SSD algorithm, the detection speed is significantly improved, which verifies the effectiveness of the algorithm.
Research on Alarm Association Mechanism of Information System Based on FP-growth Algorithm
Authors: He Yunrui , Yiying-yan  , Yijie-dang  , Yingwen-ren  , Xinyi-le
Published: December 2020

With the continuous informatization advancement of State Grid Corporation, the scale of information networks has become increasingly complicated, therefore effective alarm filtering and correlation has become the focus of the operation and maintenance of information system. In this paper, FP-growth algorithm is used to mine the association rules of alarm data in information system. Aiming at the problems of short message gateway pressure, core alarm delay and even omission caused by large-scale network alarm, the calculation method of the confidence is optimized, which solves the problem of confidence calculation distortion caused by frequent alarm term. The experimental results show that the optimized FG-growth algorithm combines the alarm information effectively and has some reference significance for the actual operation and maintenance work.
DeepCorNet: A efficient taxi-hailing prediction model
Authors: Mao Feng , Li Zhiheng , Zhang Kai
Published: December 2020

To enhance the taxi service, it is critical to improve the accuracy and efficiency of taxi-hailing prediction. Recently, the deep learning models have become the most advanced methods for taxi-hailing prediction, because they can well characterize the spatiotemporal dependencies of traffic states and achieve high prediction accuracy performances. However, most deep learning models suffer from expensive training cost. In this paper, we selected CNN as base model, the main challenge is how to convert taxi-hailing demand into image for most cases. To address this challenge, we proposed the DeepCorNet model, which generated the image of taxi-hailing demand by mutual information between regions. The experiment results showed that when taking both the model accuracy and training efficiency into consideration, the proposed model is probably more preferable, because it can conduct a relatively high prediction accuracy (close to GNN model) with much less computation efforts.
Research on 6G characteristic attenuation rate
Authors: Xu Guangbin
Published: December 2020

The terahertz band characteristic attenuation rate in 6G mobile communication system is studied. Through the model building and simulation, the results show that 6G radio wave fluctuates greatly with the increase of frequency in dry air, and there are multiple peaks. The characteristic attenuation rate of radio wave in water vapor at low frequency band is smaller than that in dry air, and adverse at high frequency band. The results also show that the characteristic attenuation rate increases with the increasement of rainfall, and is faster than that of frequency. The characteristic attenuation rate has little effect on the visibility. For frequency above 150GHz, the characteristic attenuation rate is greatly affected by snowfall intensity, while the frequency below 150GHz is relatively less affected by snowfall intensity. Under the frequency band of 20GHz, the characteristic attenuation rate increases obviously with the increase of frequency, and the characteristic attenuation rate is relatively gentle with the increase of frequency when it is above 20GHz. Meanwhile, the change is not obvious with the water content in the dust. For a certain water content, frequency from 0 to 350 GHz and temperature from 0 to 60 °C, the characteristic attenuation rate mainly increases with the increase of frequency, almost does not change with temperature.
Predicting Cardiovascular Events by Machine Learning
Authors: Zhang Caiwei , Qu Junhao , Li Weicheng , Zheng Lehan
Published: December 2020

In the field of medical treatments, machine learning has become an essential technology to mine known data. People always build models to assist doctors to judge. In this paper, 14 features of heart disease patients in two cities, Cleveland and Switzerland, are analyzed by multiple types of neuronal networks and several classifiers after cleaning the data. The model based on the featured data from heart disease patients is designed to predict whether the patients have heart disease or not. Our experimental results on the prediction of cardiovascular events in two cities show that the logistic regression classifier outperforms other methods.
Fuzzy Separation And Shrinkage Clustering
Authors: Yu Ning , Zong Yanxiang , Liang Haoran , Zhu Heying , Liu Kunhong , Wu Qingqiang
Published: December 2020

Clustering has many applications in data mining and machine learning. Fuzzy clustering methods have been widely used in clustering. However, fuzzy clustering methods still have a fatal problem: the cluster radius sensitivity problem. The cluster radius sensitivity problem means that clusters with smaller radius will predominate in clustering and obtain more data points. Aiming at this problem, we propose a fuzzy separation and shrinkage clustering algorithm (FSC). FSC uses cluster membership degrees and cluster sizes to construct a new membership distribution, and then moves the data points according to this new membership distribution. The accuracies of our algorithm on wine, iris, balance scale and seeds are as follows: 98.82%, 97.27%, 63.07% and 91.34%. Our contributions are: (1) We propose a fuzzy separation and shrinkage clustering algorithm, which can solve the cluster radius sensitivity problem. (2) The performance of our algorithm on the UCI datasets goes beyond the benchmark algorithms.
Network Traffic Classification Model Based on Multi-Task Learning
Authors: Nie Shuaibao , Jiang Lifen , Sun Huazhi , Ma Chunmei , Liang Yan , Zhou Yongheng , Zuo Ying
Published: December 2020

A multi-task learning network traffic classification model (MTL-NTC) is experimentally studied. The identification task of the MTL-NTC model contains three tasks: identifying the type of traffic, predicting the bandwidth, and the duration of the flow. Identifying the type of traffic is the main task. It includes the classification of five types of traffic. The bandwidth prediction and the duration of the flow are auxiliary tasks, which are used to improve the performance of the main task. In the public network traffic data set QUIC, the MTL-NTC model and the common model are used for comparative experiments. The experimental results show that the recognition accuracy of this model is 97.33%, which is better than the common models.
The negative mayfly optimization algorithm
Authors: Zhao Juan , Gao Zheng-Ming
Published: December 2020

The global best or historical best positions were involved in updating positions of individuals in swarms for almost all of the swarm-based nature-inspired algorithms with exceptions for the averages. However, literal research to the particle swarm optimization (PSO) algorithm had proved that the all of the candidates would also leave the global best and the historical best candidates and such improvement would result in a better performance. Similarly, the negative mayfly optimization (MO) algorithm was proposed based on such conditions. Simulation experiments were carried out and verified that the negative MO algorithm could perform better than the original MO algorithm, especially in optimizing the multimodal benchmark functions.
Parameter optimization of support vector machine based on improved grid algorithm
Authors: Wang Shenghua , Dong Li , Hua Huichun
Published: December 2020

Support vector machines SVM) is a very popular algorithm used widely in the classification problem. The basic idea of SVM is to construct two parallel hyperplanes to separate two classes of instances and maximize the distance between the hyperplanes. In this paper, we propose a new algorithm called SVM-ICC-DBTCPRP one to solve the parameter optimization problem by improving the grid algorithm used by Fayed and Atiya. In the new algorithm there are two main sub-algorithms that are used to preselect the support vectors for reducing the time of training and preselect the parameter range to reduce the number of training respectively. Six typical data sets are selected to verify the effectiveness of our algorithm. The computed results show that our algorithm has the obvious advantage on the aspect of elapsed time than the one of Fayed and Atiya.
Research on the Performance of Machine Learning Algorithms for Intrusion Detection System
Authors: Li Yue , Xu Wusheng , Ruan Qing
Published: December 2020

Intrusion Detection System (IDS) is a critical approach to ensure network system security. Currently, network attacks are complicated and volatile. Moreover, hackers are also more inclined to adopt new attack techniques to obtain users’ privacy. Under this circumstance, the intelligent intrusion detection system has become the primary approach to detect hackers’ attacks. In this study, intelligent intrusion detection models applying the novel UNSW-NB15 data set as well as various machine learning algorithms are investigated. Furthermore, data set is pre-processed through using one-hot encoding and normalization in our experiment. Subsequently, the performance comparison of six different types of machine learning algorithms in intrusion detection tasks was implemented. The experimental results reveal that in the complex and changeable network traffic data, machine learning technology has presented desired performance.
CPU utilization prediction method based on composite model
Authors: Hu Benran , Peng Wuzhuo , Li Yanjun , Ren Jiyuan , Li Yiqun
Published: December 2020

The business system server under the big data environment is always faced with a large number of data services, which makes the performance of its core hardware CPU face a serious test. Therefore, the prediction of server CPU utilization is of great significance in server resource allocation. In response to this situation, a method of server CPU utilization prediction based on ARMA-BiLSTM composite model is proposed. In this method, the original CPU utilization data is decomposed by wavelet decomposition, and the trend item and the detail item of CPU utilization data are obtained. Based on the Bi-LSTM neural network model, the trend item is modeled and predicted, and the detail item is modeled and predicted using the ARMA model. The prediction results of the two are added together to obtain the final prediction result. Through experimental verification, the proposed prediction model has higher accuracy than traditional models.
BERT-based Contextual Semantic analysis for English Preposition Error Correction
Authors: Huang Guimin , Wang Jiahao , Tang Hui , Ye Xuan
Published: December 2020

In the writing of English as a Second Language (ESL) learners, preposition related errors account for nearly 30 percent in the all grammatical errors (Bitchener et al. 2005)[1]. Unlike verbs and nouns, isolated preposition does not mean anything, but in different contexts, prepositions usually have different meanings so that ESL students hardly master how to use all prepositions correctly. In this publication, we present a preposition error correction (PEC) model based BERT (Devlin et al., 2018)[2] which contains rich contextual semantic information, fine-tuned BERT models to intensify sentence semantic in output, and calculate the preposition matching scores according to the formula.
Research on Short-Term Forecast of Power Load Based on Adam-Gru
Authors: Jia Pengtao , Miao Yunfeng
Published: December 2020

To forecast the short-term power load accurately and reliably, a short-term power load model based on gate recurrent unit was proposed. In order to improve the accuracy of the model, the Adam algorithm is used to calculate the GRU hyperparameter Optimization, so as to construct an Adam-GRU short-term power load forecasting model. The performance of the forecasting model was evaluated by the Root Mean Square Error and running time, then the forecast results were compared with LSTM method. The experimental results show that Adam-GRU has a higher accuracy than the LSTM model, an increase of 15.54%, and a time complexity reduction of 15.75%. Compared with the RNN model, the accuracy has improved 10.84%. The results show that the short-term power load forecasting model and parameter optimization method based on Adam-GRU can effectively forecast the power load data.
Research on Approximate Fitting Method of Activation Function Based on Gradient Equalization in Deep Learning
Authors: Wang Zhichen , Li Hongliang
Published: December 2020

Activation function plays an important role in neural network model. Neural networks can express more complex situations by introducing nonlinearity due to activation functions. In this paper, an approximate fitting method of activation function based on gradient bisection is proposed. The algorithm can fit the activation function curve well. You can use less space for storage on your computer. Through experiments, the storage capacity can be reduced by one time compared with the traditional approximate fitting method, but the accuracy of the model is not affected.
Research on Landscape Information Model Construction Based on Visualization Technology
Authors: Zhao Lingnong , Zhou Zhen
Published: December 2020

With the development of information technology, the functions provided by computer digital technology are more and more widely used in the process of landscape architecture design. The application of visualization technology in landscape planning and design provides a powerful help for us to understand the characteristics and behaviors of the objective existence of the world. From the perspective of landscape architecture design, this paper makes an in-depth study of the construction mode of landscape information model, and puts forward the process of landscape information model construction and its corresponding functional characteristics in combination with relevant research status at home and abroad, so as to perfectly combine theory with practice.
Application Analysis of Infrared thermal imaging Technology in Intelligent Manufacturing Field
Authors: Xingyu Chen , Hao Li
Published: December 2020

With the continuous development of science and technology, traditional manufacturing technology has also been developed. It has gradually developed in the direction of intelligent manufacturing technology through continuous integration with the advantages of machinery, energy, materials and other technologies. Intelligent manufacturing technology has been widely used by virtue of its own advantages such as high quality, high efficiency and energy saving. At present, in order to better improve the efficiency of intelligent manufacturing technology, relevant personnel have begun to apply infrared thermal imaging technology to the manufacturing field.
A General Framework for Chinese Domain Knowledge Graph Question Answering Based on TransE
Authors: Pei Zhongmin , Zhang Jie , Xiong Wei , Li Li , Luo Zhangkai
Published: December 2020

This paper introduces a general question answering (QA) framework for Chinese domain knowledge graphs to serve various industries. The question is analyzed by shielding invalid characters in this framework, and the TransE calculation of entities and relations is used to search answer, rather than traditional logical queries that rely heavily on predefined rules. In this way, the QA framework can be easily applied to different fields with little manual participation, and reduce the migration cost caused by the lack of scalability of the existing QA systems, which are designed only for specific domains. Then, the proposed framework is operated on the space launch knowledge graph and has achieved HITS@1, HITS@3, HITS@5 scores of 60.60%, 80.87%, 85.61% separately, which is competitive with other restricted domain knowledge graphs. In addition, numerical results on the knowledge graph of the Three Kingdoms and the COVID-19-Character verified the scalability of the QA framework.
Symbol-Based End-to-End Raw Audio Music Generation
Authors: Wu Changxuan , Lan Ting , Yu Chunyan , Wang Xiu
Published: December 2020

In recent years, deep learning has emerged in the audio field with many excellent models and beats non-depth methods in the quality of generated audio. This paper implements a symbol-based end-to-end music generation model. This model generates piano music corresponding to the pitch of the musical score using a two-dimensional “Piano-roll” liked structure as input. The experiments show the generated music obtains good performance and achieves a result similar to the original song in pitch, melody, and timbre. Compared with other generation methods, the input of our model is simple, easy to obtain, and can generate music through an end-to-end method.
DenseNet-ResNet-LSTM model for modulation recognition of communication signal
Authors: Li ZongYu , Zhang YanDong
Published: December 2020

The traditional artificial neural network provides a low recognition rate in the modulation recognition of communication signals, suffering from the difficulty of feature extraction. Also, it requires a high signal-to-noise ratio (SNR). In order to solve these problems, this paper proposes the combined model: DenseNet-ResNet-LSTM. In the proposed model, DenseNet and ResNet extract different spatial features of samples, and then LSTM extracts the sequence of samples. Also, the attention mechanism is employed to improve the learning efficiency and ability to learn important features. Experimental results show that the proposed model achieves higher accuracy and better generalization ability over the CNN-LSTM network.
A Face Recognition Algorithm Based on Dual-Channel Images and VGG-cut Model
Authors: Su Dongchu , Li Yong , Zhao Yunping , Xu Rui , Yuan Bo , Wu Wenjuan
Published: December 2020

In the embedded system environment, both large amount of face image data and the slow recognition process speed are the main problem facing face recognition of end devices. This paper proposes a face recognition algorithm based on dual-channel images and adopts a cropped VGG-like model referred as VGG-cut model for predicting. The training set uses the same single-layer images of the same person combined into dual channels as a positive example, and single-layer images of different people are combined into dual channels as a negative example. After model training, the trained face verification model is used as the basis of face recognition, and the final recognition result can be obtained through loop matching and similarity ranking. The experimental results on a RISC-V embedded FPGA platform show that compared with the ResNet model called in Dlib, the VGG-like model and MobileFaceNet trained by Keras, our algorithm is increased by 240×, 88×, and 19× in recognition speed, respectively without significant accuracy reduction.
Attention-DPU: Dual-path UNet with an attention mechanism for ultrasound image segmentation
Authors: Wei Pengli , Tong Mengjun
Published: December 2020

With the continuous advancement in computer vision, image segmentation has achieved fruitful results in many applications such as medical image processing. In recent years, UNet and Dual Path Network (DPN) have achieved promising results in medical image segmentation. UNet cannot effectively obtain new features and reuse features. Also, DPN cannot effectively transfer the contour information of shallow blocks to the subsequent deep blocks. This paper proposes a dual path U-shaped network with the attention mechanism (Attention-DPU); taking advantage of the two networks. In the proposed network, the ordinary convolutional layer is replaced by the micro block with a dual path. Also, the attention mechanism is adopted to improve the efficiency and accuracy of segmentation.
Joint User Pairing and Subcarrier Allocation for NOMA-based Hybrid Power Line and Visible Light Communication Systems
Authors: Teng Deyang , Zheng Yanxi , Luo Man , Luo Yiqiao , Jinyuan Wu
Published: December 2020

With the rapid growth of the number of mobile communication users, the radio frequency bands occupied by traditional radio frequency (RF) communication are becoming more and more crowded, and visible light communication (VLC) based on light emitting diode (LED) has become a powerful candidate. However, visible light cannot be used directly as an information source, and power line communication (PLC) is needed to provide data to the VLC transmitter. In a hybrid power line and visible light communication (HPV) system, the PLC can transmit data to the VLC transmitter. In order to improve spectrum utilization, we introduce non-orthogonal multiple access (NOMA) technology, but allocating all users to a resource block will result in higher computational complexity and decoding delay. This paper proposes a joint user pairing and subcarrier allocation algorithm based on fairness (IGA-JUPSA). While ensuring the performance of the system, the algorithm can also reduce the complexity of calculation and improve user satisfaction. The simulation results show that the proposed IGA-JUPSA scheme can reduce the computational complexity while ensuring the performance of the HPV system, and can also take into account the fairness of the HPV system and user satisfaction.
Research on knowledge graph model of diversified online resources and personalized recommendation
Authors: Ni Zhenglin , Ni Fangwei
Published: December 2020

This paper proposes an improved knowledge graph model to match the distinctiveness in the education field, considering the lack of robustness and resource diversity in the existing research on knowledge graphs in the education field. A recommendation algorithm based on personalized features is given on the new knowledge graph model to improve recall and precision. Finally, we verify the robustness and expression ability in course resource diversity. The results show that the recall rate of curriculum resources is improved to 0.95-0.96, personalized satisfaction is up to 0.96 and the difference of recommended resources is up to 0.9.
Human action recognition based on Kinect
Authors: An Jiahui , Cheng Xinrong , Wang Qing , Chen Hong , Li Jiayue , Li Shiji
Published: December 2020

With the emergence of Kinect, many research results have emerged in human action recognition based on skeleton information, which has promoted the development of human-computer interaction. In this paper, from the skeleton data obtained by Kinect, static features and dynamic features are extracted, and the two are merged; SVM classifier is used for action recognition. It is verified on the MSR Daily Activity 3D data set, and the experimental results show that the method in this paper improves the accuracy of action recognition.
Research on Intelligent Control of Photovoltaic Power Generation Fluctuation Based on Linear Active Disturbance Rejection
Authors: Wenxuan Gao
Published: December 2020

Nowadays, the output power of photovoltaic power generation fluctuates greatly, which endangers the safe and stable operation of the power grid. Therefore, a method for eliminating photovoltaic power generation volatility based on linear active disturbance rejection control is proposed in the paper. Moreover, through establishing the “anti-disturbance paradigm” model of the photovoltaic power generation system, the frequency scale transformation is introduced to design the linear expansion state observer is. Meanwhile, the linear expansion state observer output is converted too. Besides, proportional calculus controller is used for control, and parameter tuning is achieved through linear auto-disturbance rejection control technology to obtain optimal parameters, thereby completing the elimination of photovoltaic power generation volatility. The simulation experiment results show that when LADRC control is added, the phase A voltage fluctuation is small and the output current is relatively stable, which can effectively reduce the active power output by the photovoltaic power generation unit and improve the execution efficiency.
The study of the influence of interstellar extinction laws on the parameters of photometric system using astrophysical observations taken at EAO
Authors: Kuandykova D M , Andreev A O , Nefedyev Y A , Demina N Y , Borovskih V S
Published: December 2020

In this work, connections between UBV (PSC UBV) photometric systems for various laws of interstellar extinction are calculated on the basis of digital database on astrophysical observations of Engelhardt astronomical observatory (EAO) and using the specialized software package for analyzing brightness characteristics. The following results are obtained: 1) when using various laws of interstellar extinction, the value of difference in the position of reaction curves is proportional to the difference between UBV dependencies and color indices; 2) the positions of reaction curves and connection curves between UBV and color indices are influenced by spectral characteristics of the filters used in observations; 3) the same applies to the transformation of stellar magnitudes from one standard system to another, as response curves as a rule significantly differ; 4) another conclusion is that for any separate model of interstellar extinction the differences in color between photometric systems do not depend on spectral and luminosity classes.
A kinetic model for equilibrium binding of intercalation dye with DNA during its amplification
Authors: Fedorov A A , Murav’ev A V
Published: December 2020

Recently, a number of models of polymerase chain reaction (PCR) have been proposed. In such models, the kinetics of a reaction product and a fluorescence reporter used are usually identified. An intercalation dye is one of the two ways for “real time” detection of reaction product accumulation. In this work a PCR model is proposed, with using of intercalation dye to obtain a PCR curve. The concentration of bound intercalation dye was calculated at the end of each PCR cycle. This calculation is based on an equilibrium equation for intercalation dye binding with DNA. An analysis of simulation results demonstrates a significant difference between the accumulation kinetics of the reaction product and the fluorescent signal of the bound intercalation dye.
Visualization of the intracellular structures of bacteria using expansion microscopy
Authors: Rumyantseva N A , Vedyaykin A D , Vishnyakov I E , Khodorkovskii M A
Published: December 2020

Expansion microscopy (ExM) is a powerful tool which allows to visualize intracellular structures with increased resolution due to physical widening of the sample. ExM resolution is comparable to that of some super-resolution microscopy techniques, but it does not require the use of complex and expensive optical equipment, thereby providing improvement in resolution even if relatively simple microscopes are used. In this work we successfully utilized ExM to visualize structures formed by FtsZ protein and DNA in Escherichia coli cells. The results of the work demonstrate that structures formed by both FtsZ and DNA are highly sensitive to the sample preparation procedure which should be optimized in each case of the ExM use.
Efficiency enhancement of THz radiation from an electron bunch in a waveguide due to low-frequency stabilization
Authors: Oparina Yu S , Bratman V L , Lurie Yu , Savilov A V
Published: December 2020

Simultaneous generation of pulses of high-frequency Super-Radiance and low-frequency Coherent Spontaneous Radiation from an ultra-relativistic electron bunch moving in a waveguide placed in a spatially periodic and / or uniform longitudinal magnetic field is studied. The low-frequency radiation can weaken expansion of the bunch and decrease a velocity spread. This significantly improves electron micro-bunching and increases energy of high-frequency pulses. Such effect makes possible fairly efficient high-frequency cyclotron radiation of the bunch near an autoresonance regime, when the wave phase velocity is very close to speed of light.
Synthesis of composite single crystal structures on the basis of iron borate for fundamental studies and practical applications
Authors: Mogilenec Yu , Seleznyova K , Seleznev K. , Strugatsky M , Yagupov S
Published: December 2020

Composite single crystal structures based on iron borate FeBO3, namely diamagnetically diluted iron-gallium Fe1-xGaxBO3 and iron-aluminium Fe1-xAlxBO3 borates with low x-values, as well as doped GaBO3:Ni single crystals with Ni 0.1-0.01 mass %, have been synthesized using modified flux growth technique. Two technological modes that allowed improving the quality of the samples have been developed: crystallization in (1) open and (2) closed crucibles. Thin magnetic film of iron borate on a diamagnetic gallium borate substrate have been synthesized by liquid-phase epitaxy route.
Efficient approach to calculating radial distribution function in bcc Fe lattice
Authors: Mistryukova Lukiya A. , Kryuchkov Nikita P. , Aliev Ismail N. , Yurchenko Stanislav O.
Published: December 2020

Many properties of condensed matter systems can be described by means of pair correlation functions that makes them an important structural characteristic. The shortest-graph interpolation method allows us to calculate pair correlation functions of classical crystals with pairwise interactions between particles. However, there is still no just so simple and practical approach to predict correlation functions in crystals with many-body interactions that are ubiquitous in nature. In this work, a simple modification of the interpolation method is suggested allowing to describe pair correlations bcc Fe lattice, considered as a classical crystal with many-body interactions of embedded atom model type. It is shown that the radial distribution function of the crystal can be calculated with high accuracy if mean square displacements are known. The obtained results would be useful in various fields of condensed matter physics, materials science, and crystallography.
The initial-boundary problem for the system of 1D equations of non-Newtonian hemodynamics
Authors: Krivovichev Gerasim V
Published: December 2020

The paper is devoted to the analytical solution of the problem for 1D hemodynamical equations with periodic boundary conditions. The method of the solution is based on the asymptotic expansions on the small parameter and Fourier method. The attention is focused only on the first-order terms in the expansion. The solution, obtained for the particular case of initial conditions, is used for the comparison of rheological models of blood. It is demonstrated that the strongest damping takes place for the Power Law non-Newtonian model.
Interaction of a soliton wave with nanopores in stoichiometry crystals A3B
Authors: Zakharov P V , Starostenkov M D , Lucenko I S , Kochkin A S
Published: December 2020

Solitons are essentially nonlinear and stable objects in various environments. In this work, the molecular dynamics method is used to study the propagation of solitary waves in a discrete medium in the form of an A3B stoichiometry crystal and their interaction with nanopores. The model under consideration was a Pt 3Al crystal, the atoms of which interacted through the potential obtained by the immersed atom method. Such waves can propagate to hundreds of nanometers across the crystal. We have studied the passage of waves through a cell containing nanopores of various diameters. The mechanisms of energy dissipation in the process under consideration are shown. The distance after the obstacle at which the wave front is restored is estimated. The energy characteristics of a solitary wave after interaction with a topological defect in the form of a cylindrical nanopore are calculated. The results obtained can be useful both from a fundamental point of view in studying the properties of solitons, and from practical for non-destructive testing methods.
Dzyaloshinskii-Moriya interaction constant in iron-gallium borate single crystals
Authors: Mogilenec Yu , Seleznyova K , Yagupov S , Strugatsky M , Kliava J
Published: December 2020

The Dzyaloshinskii-Moriya interaction constant for iron-gallium borate FexGa1-xBO3 single crystals has been calculated on the basis of considering antisymmetric exchange in a pair of nearest-neighbouring magnetic ions. Both numerical and analytical calculations predict a square-law dependence of the Dzyaloshinskii-Moriya constant on the contents of magnetic ions, x, in the crystals.
The inverse problem of the oscillation of a rod with a variable cross section
Authors: Utyashev I M , Yulmuhametov A A , Aitbaeva A A
Published: December 2020

Variable cross-section rods are used in many parts and mechanisms. For example, conical rods are widely used in percussion mechanisms. The strength of such parts directly depends on the natural frequencies of vibrations. Oscillations and vibration are also used in diagnostics, for example in acoustic diagnostics of defects. The paper presents a method that allows numerically finding a variable cross section of an elastic rod from the natural frequencies of longitudinal vibrations. It is assumed that the cross-sectional area varies along the axis and is described by an exponential function of a polynomial of degree n. The boundary condition on the left end is hard, on the right-elastic. It is shown that to determine n unknown coefficients of the cross section function, n natural frequencies are required.
The growth of hexagonal and cubic GaN on a nano-patterned Si(100) substrate
Authors: Bessolov V , Konenkova E , Konenkov S , Rodin S , Seredova N
Published: December 2020

The results of studies of semipolar GaN(10-12) layers synthesized on a nano-patterned Si(100) substrate are presented. It is shown that in the method metalorganic vapor phase epitaxy, the use of a nanorelief consisting of V-shape groove with inclined faces close to the Si(111) plane can lead to the formation of regions of cubic gallium nitride in the nano-groove. Model of the origin of the cubic phase are based on the formation of AlN nuclei in (0001) and (10-10) nano-groove and the conjugation of the AlN(10-10) and c-GaN planes by the “magic mismatch” mechanism.
The study of heat-resistant fibers obtained from a melt of thermoplastic crystallizable polyimide
Authors: Vaganov G V , Ivan’kova E M , Didenko A L , Popova E N , Elokhovsky V Yu , Yudin V E
Published: December 2020

The homologous series of thermoplastic polyetherimide based on resorcinol dianhydride R (1,3-bis-(3,3’,4,4’-dicarboxyphenoxy)benzene) and tetranuclear diamine BAPB (4,4’-bis(4”-aminophenoxy) biphenyl) (R-BAPB) were synthesized in powder form. Fibers were obtained by melt spinning of this polyimide. It was analyzed, how changes in the molecular weight of polyimide can affect the ability to form fibers through the melt. The influence of the degree of orientation high-temperature drawing on the thermal mechanical properties and the change in the morphology of the polymer was studied. An increase in draw ration (DR) from 1 to 4 led to a substantial increase in tensile strength and Young’s modulus of polyimide fibers.
Strain determination in heterostructures by TEM in selected area electron diffraction mode
Authors: Snigirev L A , Kirilenko D A , Bert N A
Published: December 2020

The technique for determination of strain and elemental composition distribution across the graded layer in heterostructures by means of selected area electron diffraction in transmission electron microscope (TEM) is proposed. The approach accounts for the modification in the residual elastic strain due to sample thinning during TEM specimen preparation. The technique is approved using In0,7Ga0,3As/InxAl1-xAs/GaAs(001) and Al0,75Ga0,25N/AlN/Al2O3
heterostructures, and the results are in a good agreement with those obtained by alternative ways.
Chemometric analysis of Raman spectra of tissues of the teeth with periapical periodontitis
Authors: Timchenko E V , Timchenko P E , Zybin M A , Cherny-Tkach K B , Frolov O O , Dolgushov G G
Published: December 2020

The Raman spectra of dental tissues with periapical periodontitis have been analyzed. Chemometric analysis of the Raman spectra of hard dental tissues of healthy patients and the patients with periapical periodontitis has been carried out. The main spectral features of dental tissues with periapical periodontitis have been identified, which will further allow developing new methods of early detection of periapical periodontitis.
Investigation of characteristics of GaAs/AlGaAs p-i-n connecting tunnel diodes
Authors: Kontrosh E V , Lebedev V V , Klimko G V , Kalinovskii V S , Andreev V M
Published: December 2020

Current-voltage and capacitance-voltage characteristics of tunnel diode structures with GaAs-n++/i-GaAs/i-Al0,2Ga0,8As/Al0,2Ga0,8As-p++ active region and i-layer thicknesses of 7.5 nm and 10 nm and epitaxial growth temperature of 450 °C and 500 °C have been studied. The tunnel diode structures grown by the molecular beam epitaxy technique are intended for application as connecting elements in multijunction photovoltaic converters of high-power monochromatic optical radiation. According to the results obtained, the peak tunnel current density of up to 200 A/cm2 is achieved. Forward current-voltage and capacitance-voltage characteristics of tunnel p-i-n diode structures were measured at room temperature. The capacitance-voltage characteristics of the tunnel diodes being tested were obtained experimentally with the frequency dependence of S-parameters simulated within 10-1000 MHz at bias voltages of 0.4–1 V.
Study of a gas breakdown in a focused beam of terahertz radiation at the NovoFEL user station
Authors: Vodopyanov A , Kubarev V , Sidorov A , Shevchenko O , Gorbachev Y , Barmashova T
Published: December 2020

The paper describes the features of the design of an experimental bench for studying a discharge in a highly inhomogeneous gas stream, supported by focused radiation in the terahertz range. The setup was created at the user station of the Novosibirsk free-electron laser. The optical scheme that allows one to achieve electric field strength in the wave of up to 1 MV/cm is described. The results of the first experiments on the study of a breakdown in a focused radiation beam with a frequency of 2.3 THz are described.
Coatings with controlled degree of hydrophobicity based on powder polymer coatings
Authors: Vaganov G V , Vaganov V V , Radchenko I L , Ilyina I A
Published: December 2020

The coatings with controlled degree of hydrophobicity based on epoxy-polyester powder compositions on an aluminum surface were obtained. The study of changes in surface properties (contact angle and surface energy) and the physico-mechanical properties of the coatings, depending on the concentration of the fluorine additive, was carried out. Modification of the polymer powder composition with a fluorine additive leads to a sharp increase in the degree of hydrophobicity from hydrophobic to the formation of a superhydrophobic coating) and the saving of high mechanical properties of the coating obtained on them.
Relaxation transitions in UHMWPE near-surface layers as revealed by the thermoluminescence method
Authors: Myasnikova L P , Marikhin V A , Gladkov A K , Solov’eva O Yu , Radovanova E I , Boiko Yu M , Egorov E M
Published: December 2020

Aiming at finding the proper UHMWPE reactor powders convenient for solvent-free technology producing high-strength fibers, the comparative study of the near-surface layers of the commercial and lab-scale UHMWPE reactor powders was carried out with the help of the thermoluminiscence method. The difference in the powder glow curves and changes in them after subjecting the powders to various processing (compaction and sintering) were observed. Decomposition of the curves was carried out using Fityk program. The energy activation of the electron trap erosion, and the relative content of the shallow and deep traps in the samples investigated were calculated. The association of these observations with the mechanical propeties of the end sintered oriented product is discussed.
Powerful ultraviolet laser pulse impact on polished metals and semiconductors
Authors: Khomich Yu V , Malinskiy T V , Mikolutskiy S I , Rogalin V E , Yamshchikov V A , Kaplunov I A , Ivanova A I
Published: December 2020

Laser treatment for samples of copper, its alloys and gold was carried out with a UV pulse of nanosecond duration. After irradiation at subthreshold values of the energy density (E ∼ 0.2 - 0.8 J/cm2) the noticeable changes in the surface layer were revealed. These are traces of thermoplastic deformation resulting from laser exposure. They appear as uneven rise of the irradiated sample surface area up to 1 μm. The effect is cumulative, because the height of the uplifts increases with increasing number of impact pulses. In addition, the characteristic features of high-temperature plastic deformation were observed in the form of crystallographic slip and grain-boundary slippage. At E ∼ 1 J/cm2 or more the optical breakdown occurred with the formation of a crater on the metal surface, that precludes the detection of described effects. The mechanical impulse of a laser plasma, when exposed to a metal surface, prevents the thermomechanical expansion of the material, and therefore, similar effects have not been previously observed. On the surface of materials with a significantly larger elastic limit (single crystals of germanium and silicon, a tungsten carbide) this phenomenon was not observed, because the generated thermomechanical stresses were insufficient to create conditions of plastic deformation.
Contactless method for online control tension of radio-reflective mesh surface of large-sized folding mirror antennas
Authors: Sayapin S N
Published: December 2020

A new contactless method for online control tension of a radio-reflective mesh surface of a large-sized folding mirror antenna is presented. The method is based on revealing the correlation between Moire patterns and net-shaped curtain uniformity and tension. The advantages of the method are presented. Its main advantage lies in the fact that it is possible to set the net-shaped curtain on the folding skeleton of an antenna reflector in the online mode. The presented method is universal and can be used not only to manufacture antenna reflectors with the working surface in the form of a net-shaped curtain but also in any other structures in which the checked element is a net, regardless of the material of which it is made. A way to apply the method is presented.
Mechanical analogue in hydroelasticity
Authors: Pozhalostin A.A. , Goncharov D.A.
Published: December 2020

Lineal oscillation modelling of various mechanical systems is a quite common way of representation and simplification of rather complicated systems. One of the most impressions and exciting appearance of lineal oscillation modelling was made by RAS academician Konstantin Sergeevich Kolesnikov in a problem of liquid-structure interactive and the influence of that interactive on vehicle dynamics, especially in a case of rocket motion. K.S. Kolesnikov considered mathematical pendulum according to the problem of the small oscillations of an ideal liquid in a rigid cylindrical shell.
Mathematical modeling of the loading process dump truck
Authors: Baryshnikov Yu N , Panshina A V
Published: December 2020

The article solves the problem of the impact of the load when loading a dump truck. The car is modeled by a rigid beam on two elastic supports of different stiffness with shock absorbers. The impact of the load is absolutely inelastic in the center of mass of the beam. The mathematical model of the car is based on the Lagrange equations of the 2nd kind in the form of a system of two inhomogeneous linear differential equations of small oscillations of the Beam-Load system. An analytical solution of this system is obtained in the form of the sum of two damped main oscillations, and expressions are obtained for the conditional amplitudes and phase shifts of the main oscillations, taking into account the initial conditions determined by the impact of the load. Based on the results obtained, an algorithm and a program for solving the problem were developed. A numerical experiment was performed on loading a BelAZ-7555B dump truck.
Walking wheel
Authors: Lapshin V V
Published: December 2020

The dynamics of a 2D walking wheel motion down an inclined plane is analytically investigated in nonlinear formulation. It is the simplest model of a bipedal walking. The possible cases of the motion of the walking wheel are investigated at various values of the inclination of the support surface and the initial angular velocity of the wheel. It is shown that various modes of motion of the walking wheel are possible. The most interesting of which is the existence of a stable periodic solution (self-oscillations).
Effect of a floating particles layer on breaking surface gravity waves
Authors: Kalinichenko V A
Published: December 2020

The results of experiments on the influence of a layer of particles of positive buoyancy on the suppression of the breaking process and the regularization of a standing gravity wave on a free surface of water in a rectangular vessel are discussed. The oscillations of a two-layer system in a barotropic mode are considered. Parametric resonance is used to excite the waves in a rectangular vessel. The effect of increase in the upper layer thickness on the limit steepness of the regular wave and its dissipative properties are considered. It is shown that the use of floating polystyrene particles as the upper layer changes significantly wave mode dynamics, namely, regularization of waves with complete suppression of breaking mechanisms.