bluuebunny/crossref_metadata_2025 huggingface dataset:
An allosteric HTRA1-calpain 2 complex with restricted activation profile
Authors: Rey Juliana , Breiden Maike , Lux Vanda , Bluemke Anika , Steindel Maike , Ripkens Kamilla , Möllers Bastian , Bravo Rodriguez Kenny , Boisguerin Prisca , Volkmer Rudolf , Mieres-Perez Joel , Clausen Tim , Sanchez-Garcia Elsa , Ehrmann Michael
Published: March 2022

Significance

Classic serine proteases are synthesized as inactive precursors that are proteolytically processed, resulting in irreversible activation. We report an alternative and reversible mechanism of activation that is executed by an inactive protease. This mechanism involves a protein complex between the serine protease HTRA1 and the cysteine protease calpain 2. Surprisingly, activation is restricted as it improves the proteolysis of soluble tau protein but not the dissociation and degradation of its amyloid fibrils, a task that free HTRA1 is efficiently performing. These data exemplify a challenge for protein quality control proteases in the clearing of pathogenic fibrils and suggest a potential for unexpected side effects of chemical modulators targeting PDZ or other domains located at a distance to the active site.
Atomic-number (
Z
)-correlated atomic sizes for deciphering electron microscopic molecular images
Authors: Xing Junfei , Takeuchi Keishi , Kamei Ko , Nakamuro Takayuki , Harano Koji , Nakamura Eiichi
Published: March 2022

Significance

Atomic resolution transmission electron microscopy (TEM) has opened up a new era of molecular science by providing atomic video images of dynamic motions of single organic and inorganic molecules. However, the images often look different from the images of molecular models, because these models are designed to visualize the electronic properties of the molecule instead of nuclear electrostatic potentials that are felt by the e-beam in TEM imaging. Here, we propose a molecular model that reproduces TEM images using atomic radii correlated to atomic number (
Z
). The model serves to provide a priori a useful idea of how a single molecule, molecular assemblies, and thin crystals of organic or inorganic materials look in TEM.
Horizontal transmission enables flexible associations with locally adapted symbiont strains in deep-sea hydrothermal vent symbioses
Authors: Breusing Corinna , Genetti Maximilian , Russell Shelbi L. , Corbett-Detig Russell B. , Beinart Roxanne A.
Published: March 2022

Significance

In marine ecosystems, transmission of microbial symbionts between host generations occurs predominantly through the environment. Yet, it remains largely unknown how host genetics, symbiont competition, environmental conditions, and geography shape the composition of symbionts acquired by individual hosts. To address this question, we applied population genomic approaches to four species of deep-sea hydrothermal vent snails that live in association with chemosynthetic bacteria. Our analyses show that environment is more important to strain-level symbiont composition than host genetics and that symbiont strains show genetic variation indicative of adaptation to the distinct geochemical conditions at each vent site. This corroborates a long-standing hypothesis that hydrothermal vent invertebrates affiliate with locally adapted symbiont strains to cope with the variable conditions characterizing their habitats.
Synchronous spiking of cerebellar Purkinje cells during control of movements
Authors: Sedaghat-Nejad Ehsan , Pi Jay S. , Hage Paul , Fakharian Mohammad Amin , Shadmehr Reza
Published: March 2022

Significance

The information that one region of the brain transmits to another is usually viewed through the lens of firing rates. However, if the output neurons could vary the timing of their spikes, then, through synchronization, they would spotlight information that may be critical for control of behavior. Here we report that, in the cerebellum, Purkinje cell populations that share a preference for error convey, to the nucleus, when to decelerate the movement, by reducing their firing rates and temporally synchronizing the remaining spikes.
Conformational snapshots of the bacitracin sensing and resistance transporter BceAB
Authors: George Natasha L. , Schilmiller Anthony L. , Orlando Benjamin J.
Published: March 2022

Significance

Many gram-positive organisms have evolved an elegant solution to sense and resist antimicrobial peptides that inhibit cell-wall synthesis. These organisms express an unusual “Bce-type” adenosine triphosphate–binding cassette (ABC) transporter that recognizes complexes formed between antimicrobial peptides and lipids involved in cell-wall biosynthesis. In this work, we provide the first structural snapshots of a Bce-type ABC transporter trapped in different conformational states. Our structures and associated biochemical data provide key insights into the novel target protection mechanism that these unusual ABC transporters use to sense and resist antimicrobial peptides. The studies described herein set the stage to begin developing a comprehensive molecular understanding of the diverse interactions between antimicrobial peptides and conserved resistance machinery found across most gram-positive organisms.
Verb stem alternation in Gongduk
Authors: Gerber Pascal
Published: March 2022

This paper provides a first overview of verb stem alternation in Gongduk (eastern Bhutan, Trans-Himalayan). Verb stem alternation in Gongduk is conditioned both by morphophonology and by grammatical categories. This paper presents both the morphophonologically transparent as well as the phonologically opaque, paradigmatic stem alternation. The analysis provided in this paper identifies seven verb classes and a small number of irregular verbs. Additionally, this paper provides some diachronic observations on Gongduk verb stems and shows that different stem classes of Gongduk preserve derivational morphology (valence, direction) with cognates in other branches of the language family. Gongduk therefore provides important evidence for the historical investigation of derivational morphology and verb stem alternation in Trans-Himalayan.
Effect of Zn interlayer on friction stir butt welding of A1100 and SUS316L stainless steel
Authors: Saleh Mohamed , Liu Huihong , Ushioda Kohsaku , Fujii Hidetoshi
Published: March 2022

The effect of Zn interlayer on the microstructure and mechanical properties of dissimilar A1100 and SUS316L friction stir welded (FSW) butt joints was investigated. The results showed that Zn could improve the joint's tensile strength. However, a complete dissolution of the Zn interlayer was necessary to achieve a sound joint. During the FSW process, the stirring action of the tool dispersed the Zn into the A1100 matrix forming a solid solution of Zn. A direct relationship was found between the tool rotational speed and the Zn dissolution rate. Also, the addition of Zn inhibited the Al–Fe IMCs growth, which played a positive role in the obtained tensile strength.
Prediction and validation of intermetallic compound formation during friction stir welding of AA6061 to commercially pure copper
Authors: Karrar Gihad , Galloway Alexander , Toumpis Athanasios , Al-Badour Fadi , Li Hongjun
Published: March 2022

A novel approach for predicting the intermetallic compound (IMC) formation during friction stir welding (FSW) of AA6061 to commercially pure copper has been developed, in addition to their effect on mechanical properties. The temperature distribution of the aluminium to copper weld nugget determined by a finite element model, the use of an Al–Cu phase diagram and the elemental concentration of copper and aluminium in the weld nugget have been combined to predict and validate several IMCs present in the different zones of the weldment. The results of performing butt-welding of these dissimilar metals using the FSW process demonstrated that the highest ultimate tensile strength of 194.5 MPa was achieved at 1500 rev min−1 tool rotational speed, 100 mm min−1 traverse speed and a zero-tool offset.
RF MEMS filter based on dual liquid variations
Authors: Habbachi Nizar , Besbes Kamel
Published: March 2022

This paper discusses the behavior of RF MEMS tunable microwave filter. We have modeled the distribution of magnetic field and electric current density in order to reveal the comportment of each device and to evaluate the relation between the frequency response and the microwave performances. From several modelling and simulations, we catch the resonance phenomenon for magnetic and electric fields at different conditions. Hence, in order to develop a reconfigurable MEMS ensuring a function of tunable band-pass filters, we have identified conditions allowing to vary the resonance frequency from Fres = 0.42 GHz to Fres = 1.85 GHz ensuring a large total variation of Tr = 340.5%. The structure is fabricated using SU-8 resin for circulating microchannels and sealing layers. The extracted parameters from measurements results and retro-simulation reveal a diminution of the total tuning range.
Picoliter liquid operations in nanofluidic channel utilizing an open/close valve with nanoscale curved structure mimicking glass deflection
Authors: Sano Hiroki , Kazoe Yutaka , Morikawa Kyojiro , Kitamori Takehiko
Published: March 2022

Microfluidics has downscaled to nanofluidics to achieve state-of-the-art analyses at single/countable molecules level. In nanofluidic analytical devices, switching and partitioning reagents in nanochannels without contamination are essential operations. For such operations, we have developed a nanochannel open/close valve utilizing elastic glass deformation. However, owing to a rectangular-shaped nanospace, sample leakage due to diffusion through the remaining open space in the closed valve occurs and causes contamination. Herein, we propose a fabrication method of nanoscale curved structure resembling the glass deflection shape to develop the nanofluidic valve for switching and partitioning operations in nanochannels. After fabricating a four-stepped rectangular nanospace by electron beam lithography and dry etching, the space was plastically deformed using an impulsive force by pressing the chamber more than 20 000 times. A smoothly curved structure with a high aspect ratio of 750 (75 μm width and 100 nm depth) fitting the glass deflection shape, which has been difficult for conventional methods, was successfully fabricated. Utilizing a valve with the curved structure, the solute leakage through the closed valve was reduced to less than 0.5% with a 94% decreased diffusion flux compared to previous valve with the rectangular-shaped structure. The developed valve realized switching of 72 pl reagents in a nanochannel with a response time of 0.4 s, which is sufficient for nanofluidic-chromatography, and it correctly worked even after an interval of 30 min, which is required for repeatable nanofluidic analyses. The newly developed valve will contribute to realizing versatile nanofluidic analytical devices.
Data-driven model-free adaptive sliding mode control for electromagnetic linear actuator
Authors: Gu Chaofan , Tan Cao , Li Bo , Lu Jiayu , Wang Geng , Chi Xuwen
Published: March 2022

A data-driven model-free adaptive sliding mode control (MFASMC) method is proposed to tackle the problems of inaccurate model and time-varying parameters of a micro electro-magnetic linear actuator system, considering the dependence of existing model-based control methods on the system dynamics model and the impact of unmodeled dynamics on the control performance. Firstly, the pseudo-gradient concept in the model-free adaptive control (MFAC) framework is used to transform the electromagnetic linear actuator dynamics model, which is difficult to obtain parameters accurately, into a full-format dynamic linearized data model, the dependence of the controller on the electromagnetic linear actuator model is reduced. To compensate for the effects of unknown perturbations, an improved discrete sliding mode exponential convergence law is introduced to derive a new composite control algorithm based on the pseudo partial derivative estimator, which improves the robustness of the control system. Then, the convergence of the control error and the stability of the system are demonstrated by theoretical analysis. The results show that the proposed MFASMC reduces the 10 mm step response time of the electromagnetic linear actuator by 46.3% and 25.3% compared with proportional-integral-derivative control (PID) and MFAC. The phase lag time and root-mean-square error of MFASMC under sinusoidal conditions are 0.8 ms, 0.178 mm respectively, and the steady-state error does not exceed 0.05 mm. The experimental and simulation results keep the error within 5%, the proposed control algorithm has good trajectory tracking response speed and control accuracy, and has good robustness to system uncertainty and external force disturbance.
Origin of photo-enhanced hysteretic electrical conductance in nanostructured silicon-based heterojunction
Authors: Chakrabarty Sudipta , Das Jayoti , Minhaz Hossain Syed
Published: March 2022

Photo-enhanced hysteretic I–V curves have been observed under reverse bias in a p-i-n structure containing electrochemically etched nanostructured silicon (Si) sandwiched between p-Si and n-type a-Si:H layers. These curves have been found to depend on intensity of incident illumination and structural morphology of the nanostructured Si layer. The conductance in trace path is lower than that in retrace path. Charge transport mechanism in this structure has been interpreted using microscopic description of charge trapping and detrapping in the defect states present at the interface of nanocrystalline silicon core and oxide shell in the active layer. An applied voltage dependent probability distribution of trapping and detrapping has been calculated in light of classical random walk problem. The trapping/detrapping of charges leading to development/destruction of potential barriers in the path of charge flow shows an analogy with the river bed deposition/erosion. The rate of trapping has been considered to depend on the empty defect states whereas the rate of detrapping depends on the already filled defects. Moreover, the rate of both trapping and detrapping is expected to depend on the charge flow rate. All these considerations lead the I–V relations for trace and retrace paths in reverse bias fitting nicely with experimental I–V loops. The observed peaks in the voltage dependent dynamic conductance in trace and retrace paths have been explained as a consequence of development and destruction of two barriers in the active layer for electrons and holes separately. Best fit values of the fitting parameters indicates that the trace path is dominated by holes whereas the retrace path is dominated by electronic transport. The difference in mobility of electron and hole leads to different trapping and detrapping rates in the two paths resulting in the observed hysteresis.
Impact of N2 admixture on the synthesis of graphitic carbon nanoparticles using atmospheric-pressure microwave plasma
Authors: Heo Seonil , Lim TaeGyeong , Kim Byeong Soo , Suk Ji Won , Bak Moon Soo
Published: March 2022

Atmospheric-pressure microwave plasma was utilized for catalyst-free gas-phase synthesis of graphitic carbon nanoparticles by adding CH4 to a mixture of N2 and He. The impact of N2 on the formation of the graphitic carbon nanoparticles was analyzed by increasing the N2 flow rate from 0 to 20 slpm and decreasing the He flow rate from 40 to 20 slpm simultaneously. The addition of N2 altered the morphology of the carbon nanoparticles to obtain flatter and larger shapes. Furthermore, carbon nanoparticles synthesized with N2 possessed more graphitic structures with higher C/O ratios and larger crystallite sizes than those synthesized without N2. The analysis of gas compositions at thermodynamic equilibrium states demonstrated that CN and HCN were the dominant precursor species when N2 was added. The presence of N atoms or N-containing species seem to have a synergistic effect combined with H atoms on the formation of the graphitic carbon nanoparticles.
Traceable x-ray focal spot reconstruction by circular edge analysis: from sub-microfocus to mesofocus
Authors: Bircher Benjamin A , Meli Felix , Küng Alain , Sofiienko Andrii
Published: March 2022

The size and shape of the focal spot, i.e. the area where x-rays are generated in an x-ray tube, is a key figure of merit of a radiographic imaging system, because it governs the achievable resolution and, if the shape is irregular, can introduce anisotropic blur in the radiographs. Size and shape are mainly determined by the diameter of the accelerated electron-beam and electron interactions with the target material. Since focal spot parameters change over time, due to target wear and drift in the electron optics, traceable methods to monitor the focal spot size and shape are required. Here, we present a method to map the 2D intensity distributions of focal spots, ranging from sub-microfocus (0.1 µm) to mesofocus (>50 μm). The method evaluates radial profiles of a circular aperture and applies filtered back projection to reconstruct the focal spot intensity distribution. Special emphasis is placed on traceability and influence factors, such as image noise and aperture geometry. The method was validated over a focal spot range from 0.3 µm to 200 µm. Experimental results were compared to complementary methods, using line pair gauges (JIMA) for microfocus (1 µm–10 µm), e-beam characterisation for sub-microfocus (0.3 µm–1.0 µm), and pinhole camera imaging for mesofocus spots (50 µm–200 µm). Good agreement between the focal spot reconstruction and the complementary methods was achieved. Limitations due to edge penetration, caused by the finite thickness of the circular aperture gauge, were experimentally verified. From these findings, we derived recommendations for an improved gauge geometry, regarding its thickness and the aperture diameters. The method perfectly complements the well-established pinhole imaging, which is limited to focal spots larger than ∼50 µm.
Three distinct phases of electron heating in an rf-driven atmospheric-pressure plasma jet
Authors: Park Sanghoo , Yoon Sung-Young
Published: March 2022

Cold plasma jets represent one of the most attractive and versatile plasmas, and active studies on plasma properties such as electron density (n
e) and temperature (T
e) have facilitated the development and implementation of plasma jets. Here we demonstrate the temporal evolution of n
e and T
e in a radio-frequency (rf)-driven argon plasma jet operating at atmospheric pressure. The plasma jet is driven by 5 MHz sinusoidal rf power modulated by a 50 kHz square pulse with a 75% duty ratio. A 532 nm Nd:YAG laser is applied to the plasma, and laser Thomson scattering measurements are performed using a triple-grating spectrometer coupled to an intensified CCD camera. From this investigation, we find that n
e and T
e vary during the pulse repetition period of 20 μs in the ranges of (2–12) × 1018 m−3 and 0.3–6.0 eV, respectively. With respect to the 5 MHz period (200 ns), T
e varies with the rf oscillating field while n
e remains constant. Special attention is given to three distinct electron characteristics depending on the pulse phase in the plasma jet—ionizing (on-pulse), stationary and recombining (off-pulse) states. Our measurements will be valuable for related experimental and numerical plasma research and provide further insights into the effect of rf pulsing on the electron kinetics in atmospheric-pressure plasmas.
Epitaxial growth of GaAsBi on thin step-graded InGaAs buffer layers
Authors: Paulauskas T , Devenson J , Stanionytė S , Skapas M , Karpus V , Čechavičius B , Tumėnas S , Strazdienė V , Šebeka B , Pačebutas V
Published: March 2022

Molecular beam epitaxy growth and analysis of GaAsBi on compositional step-graded InGaAs buffer layers are presented in this study. The developed buffer is only 240 nm thick, exhibits very low surface roughness while reaching up to 0.46% lattice-mismatch with a GaAs substrate. Reciprocal-space mappings showed that 500 nm thick GaAsBi layers with 2.7%–5.3% Bi remain pseudomorphic with the InGaAs buffer, in contrast to GaAsBi grown on GaAs that were found to incur up to 50% lattice relaxation. CuPtB-type ordering and associated polarized photoluminescence were also found in the bismide layers grown on the InGaAs buffers. Optical anisotropy of a strain-free 2.7% Bi GaAsBi was further analysed by a suite of optical techniques indicating that the valence band splitting is ∼40 meV. This study advances synthesis techniques of thick GaAsBi layers for optoelectronic device applications.
Critical current and loss character of quasi-isotropic strands with resistance
Authors: Li Shuo
Published: March 2022

A quasi-isotropic strand has a central rotational symmetry structure which shows good isotropic performance on magnetization loss when the strand is subjected to an externally applied alternating magnetic field in various directions. This paper studies the critical current and ac loss character of quasi-isotropic strands by considering the resistance between tapes based on the minimum electromagnetic entropy production method. The quasi-isotropic strands show resistance dependence on critical current, transport loss, and magnetization loss. The resistance between tapes can increase the critical current without significant increases in the total loss. High-frequency excitation conditions do not increase the loss per cycle either. The results indicate that quasi-isotropic strands are highly suitable for power cables and other high-power applications.
Stability of KdV solitons with respect to transverse perturbations: Absolute and convective instabilities
Authors: Ruderman M S , Petrukhin N S , Pelinovsky E
Published: March 2022

We study the stability of one-dimensional solitons propagating in an anisotropic medium. We derived the Kadomtsev-Petviashvili equation for nonlinear waves propagating in an anisotropic medium. By a proper variable substitution this equation reduces either to the KPI or to the KPII equation. In the former case solitons are unstable with respect to the normal modes of transverse perturbations, and in the latter they are stable. We only consider the case when the solitons are unstable. We formulated the linear stability problem. Using the Laplace–Fourier transform, we found the solution describing the evolution of an initial perturbation. Then, using Briggs’ method we studied the absolute and convective instabilities. We found that a soliton is convectively unstable unless it propagates at an angle smaller then critical with respect to a critical direction defined by the condition that the group velocity is parallel to the phase velocity. The critical angle is proportional to the ratio of the dispersion length to the soliton width, which is a small parameter. The coefficient of proportionality is expressed in terms of the phase speed and its second derivative with respect to the angle between the propagation direction and the critical direction. As an example we consider the stability of solitons propagating in Hall plasmas.
Dynamical dark energy models in the light of gravitational-wave transient catalogues
Authors: Escamilla-Rivera Celia , Nájera Antonio
Published: March 2022

The study of current gravitational waves (GW) catalogues provide an interesting model independent way to understand further the nature of dark energy. In this work, we present an update of the constrains related to dynamical dark energy parametrisations using recent Gravitational-Wave Transient catalogues (GWTC-1 and GWTC-2) along with Type Ia supernova (SNeIa) and Cosmic Chronometers (CC) catalogues. According to our Bayesian results using the full SNeIa+CC+GW database, the ΛCDM model shows a strong preference against two dark energy parameterisation known as Barboza-Alcaniz (BA) and the Low Correlation (LC) models. Also, we obtain a very strong preference against the Chevallier-Polarski-Linder (CPL) model. Furthermore, we generated a mock GW catalogue and estimate that we require approximately 1000 standard sirens to have a constrain of H
0 within 1% relative error, quantity that is out of reach of current standard sirens candidates in GWTC-1 and GWTC-2 catalogues.
The protection of megascience projects from deepfake technologies threats: information law aspects
Authors: Galyashina E I , Nikishin V D
Published: March 2022

The paper examines the potential threats of the malicious use of deepfake technology to destabilize and discredit megascience projects in the global information space. The phenomenology of using artificial intelligence (AI) to create video recordings and voice messages, in which people do and say something that did not take place in reality, is considered. Special attention is paid to speech synthesis technologies based on arbitrary text and spoofing, i.e. replacing the speaker’s personality while preserving the content of the original speech message. The authors’ definition of a voice deepfake is as follows: an artificial creation of digital voice clones of a person for the purpose of intellectual or material forgery (fabrication of a pseudo-real information and communication event). A specific classification of deepfake technologies according to the types of their criminogenic use is given in the article. The authors highlight the imperfection of the Russian legislation on the legal protection of the individual voice of a person as an intangible value and on the protection of individuals from the unauthorized use of voice personal data taking into account the policy of social networks (Facebook, Twitter, TikTok) aimed at protecting users from synthesized audio and video disinformation. Based on the results of the research, a number of decisions are proposed to change the criminal and civil legislation in order to ensure the national security of the state, to protect international megascience projects, other scientific activities and individuals from the negative consequences of the potentially destructive and / or criminal use of voice deepfakes, including discrediting and defaming international megascience projects and their representatives in the media environment. The proposed legislative amendments may be used in other contexts by foreign countries and interstate associations.
Ensuring information security in the field of remote work
Authors: Kolomoets E
Published: March 2022

Remote work is a forced measure introduced by employers in order to prevent a viral infection. For employees, there are pluses in remote work - saving time and money on the road and high labour productivity because nothing distracts. There is a separate issue of information security for the employer when organising such a work regime for their employees. Any use of materials is allowed only with a hyperlink. Nowadays, in the realities of distance work, information security is coming first. Employees send all the information online; they use their data and send confidential information. Protection of personal data becomes a crucial point. The article deals with problems of ensuring information security in the field of remote work. The problems of information security during restrictive actions in connection with the coronavirus pandemic and the transfer of personnel to remote work are discussed. The threat of information leaks through remote workers is relatively high since the specialists responsible for the organisation’s information security do not have the opportunity to apply the entire arsenal of technical means and policies, with the help of which security is ensured at workstations in the office. Information leakage will lead to severe problems, so it is essential to consider what means you can use to ensure the company’s information security.
New challenges and approaches in training personnel for research projects of the “MegaScience” class
Authors: Barbashina N S , Astapov I I , Delov M I , Moshkova D M , Vasiliev A N
Published: March 2022

MegaScience projects are unique scientific experiments and facilities of a large scale that were initiated to allow to go beyond modern knowledge in the field of fundamental sciences and open up new opportunities in the technological development. The implementation of such complex projects requires the combined efforts of many scientists and institutions at national and multinational level. The paper presents an analysis of new trends in the training of researchers in the field of elementary particle physics, high energy physics and cosmophysics for research projects and experiments at MegaScience facilities. The authors consider the vast experience of extensive training of MEPhI students for fundamental science and analyzed new approaches to organizing the individual training of researchers at the university. The result of this work was presented and discussed within the proceedings of the Third Conference “Personnel training and legal support for the implementation of scientific projects of the Mega-science class” organized by National Research Nuclear University MEPhI and Kutafin Moscow State Law University on 17 June 2021.
Training of academic lawyers for implementation of high-tech research projects (“Digital Law”, “Megascience” and “Lex genetica” projects case study)
Authors: Zakharova M V
Published: March 2022

The legal profession has both conservative and innovative features. On the one hand, present-day lawyers are the heirs of the centuries-old tradition of global jurisprudence. On the other hand, the technological challenges of the external environment inevitably transform not only the legal map of the world, but also the peculiarities of training for modern legal professionals. The article deals with the main transformational paradigms of legal professionals training, using the example of three high-tech spheres of public life – genetics, digital economy and mega-science installations development. Academic lawyers (legal scholars) are in many ways at the forefront of the present-day jurisprudence, defining both the present and the future of the global legal space. Their training takes longer than the standard education course for lawyers. The data of the Russian legal system and the legal systems of other countries, as well as international legal practice, served as the empirical basis for the research.
Mechanisms for attracting foreign scientists
Authors: Karandaev I Y , Lozovskij D L
Published: March 2022

The brain drain problem is typical not only for the Russian Federation, but also for other developing and developed countries. The article presents the mechanisms of attracting foreign scientists on the example of the European Union, the People’s Republic of China, and the Federal Republic of Germany. On the basis of the analysis and generalization, the features of the mechanisms used to attract foreign scientists and their effectiveness are highlighted.
Frequency Increments Optimization Based on IPSO to Extend Beam Dwell Time for Frequency Diverse Array
Authors: Pan Yuwen , Yang Yuanwang , Jiao Libin
Published: March 2022

Compared with traditional phased array radar, frequency diverse array (FDA) can form a range-dependent beampattern and overcome the shortcoming that the traditional phased array radar cannot effectively control the range direction of the transmit beam. Nonuniform linear frequency increments has been widely applied in FDA to promote the performance of FDA. However, few methods can effectively extend the beam dwell time. In this paper, we propose an improved particle swarm optimization algorithm (IPSO) that can adjust the frequency increment of every array element to extend the dwell time of the beam within a period of time. Numerical simulation results show that our method can outperform other existing methods, which implies that a more stable and flexible FDA communication system can be achieved for the proposed method.
Anti-asphyxiation System for Children in Vehicle Based on Multi-sensor Fusion
Authors: Peng Shaolong , Yang Bokang , Yang Zhihui , Shi Shaoyue
Published: March 2022

With the rapid development of automobile industry, cars have been widely used in thousands of households. But the car brings convenience to people’s life, at the same time, the safety hidden trouble it brings is also more prominent and serious. In recent years, more and more accidents caused by asphyxiation of children in cars have prompted the scientific community to pay attention to and study this phenomenon. Therefore, we design a vehicle anti-asphyxiation system based on multi-sensor fusion.
Bayesian Regression Analysis of Spatio-temporal Location Information of Ship Electromagnetic Signal
Authors: Wang Min , Sun Chong , Wu Rangcheng , Shi Xiangqian
Published: March 2022

For spatio-temporal location information of electromagnetic signals according to maritime ship targets, the regression model based on Bayesian statistics is established based on the Bayesian estimation method, and some examples are analyzed. The results show that the model reduces the error, improves the accuracy of the sample data, significantly improves the data pretreatment effect, and effectively facilitates the further modeling and analysis of the target identification problem, so as to increase the credibility of the ship target identification.
Allocation Structure Optimization of Distributed Power Supply Based on Improved Self-adapting Cuckoo Algorithm
Authors: Li Lei , Gao Guige
Published: March 2022

Aiming at the problems of environmental protection and economy caused by the integration of distributed power (DG) into distribution network, an optimal allocation model of distributed power was established with generation cost, network loss cost and DG environmental cost as the optimization objectives. In order to solve the model, an improved adaptive cuckoo algorithm was introduced, which combined the discovery probability and scaling factor of the adaptive strategy. Through the example analysis of IEEE-33 bus, the simulation results of different algorithms are compared, for which, in distributed power allocation structure, the availability and advantages of this improved algorithm optimization are verified.
Digital Analysis of Movements on Characters Based on OpenPose and Dlib from Video
Authors: Ye Kai , Dong Jianmin , Zhang Lijun
Published: March 2022

In order to avoid the disadvantages of complex operation and expensive equipment for the extraction method of motion capture systems and other equipment , a method which can extract key points of characters movements was proposed based on video of Tibetan drama with OpenPose and Dlib. And, the movement trajectory and movement fluctuation amplitude which were obtained by digital analysis from characters’ movement were used as indicators to provide a quantitative plan for movement essentials of Tibetan drama’s performing arts. The digital analysis was implemented by tracking key points’ two-dimensional coordinate data with the form of line chart and reflecting movement fluctuation amplitude with absolute difference of the same key point’s two-dimensional coordinate data belonged to two frame of video. Experiments showed that this method was suitable for video and was correct and effective in the image coordinate system, which provided a reliable foundation for the digital analysis.
A Text Location Method for Sign Based on Pixel-level Gradient Ray Images and Edge Contour Mapping
Authors: Du Jiani , Bai Jun , Zhou Guanglu
Published: March 2022

Compared with deep learning methods, traditional image processing methods have lower computational costs and have advantages for typical problems such as sign text, this paper proposes a sign text location method based on pixel-level gradient ray map and edge contour mapping. First, based on image pre-processing, the pixel-level gradient ray map is obtained by using the Stroke Width Transform. Then, using the Maximally Stable Extremal Region method to locate the irregular text candidate area in the ray map. At the same time, add a mask layer to filter the irregular candidate area, and then regularize the candidate area and perform Non-Maximum Suppression processing. Finally, the background non-text candidate area is processed by extracting the mapping of the closed edge contour of the image, and the remaining text area positioning candidate frame coordinates are mapped back to the original picture. The experimental results show that the method is simple and clear, the effect is remarkable, and it has good robustness to the sign of different sizes.
A S-transform Based Algorithm for Doppler Frequency Rate-of-Change Estimation from Coherent Pulse Train
Authors: Lan Zhangfu , Peng Huafeng , Zhao Peiyan
Published: March 2022

The traditional Fourier correlation method has the problem of poor accumulation effect, which leads to the low estimation accuracy of Doppler frequency change rate coherent pulse signal under the condition of low signal-to-noise ratio or short pulse duration. To solve this problem, an estimation algorithm based on S-transform is proposed to estimate the Doppler frequency change rate. By means of higher time-frequency aggregation of S transform, the coherent accumulation of the coherent pulse signal is better realized; Then the high accuracy Doppler frequency change rate is obtained by using the minimum variance criterion in the phase domain. Theoretical derivation and simulation results show that the algorithm in this paper can improve the accuracy of about 1 times compared with the traditional algorithm. It lays a solid foundation for the estimation of the high-precision Doppler frequency change rate in the practical application of subsequent projects, and improves the accuracy of target positioning and tracking.
Research and Design of Remote Online Supervision System of Coal Mine Electromechanical Equipment
Authors: Chen Yunqi , Xu Jin
Published: March 2022

Increasing the supervision of coal mine electromechanical equipment is an urgent need to ensure the safe production of coal mines. This paper designs and develops a coal mine electromechanical equipment supervision system, which includes four parts: mine-side monitoring subsystem, mine-side data acquisition and transmission module, local-side data analysis and storage module, and coal mine electromechanical equipment supervision platform. It realizes coal mine ventilator, drainage pump, air compressors, hoists and other major electromechanical equipment online monitoring and equipment failure analysis. The system satisfies the remote online inspection and management of equipment by multi-level departments, reduces the possibility of enterprise accidents, innovates the supervision mode, and improves the efficiency of supervision.
An Anti-noise Fault Detection Algorithm for Distribution Network
Authors: He Ming , Li Yi , Zou Wan , Duan Xiangxi , Gao Jie , He Rui
Published: March 2022

Power fault directly threatens the safety of the power system. Aiming at the recognition ability of power line fault detection disturbed by noise, A fault detection method based on attentional mechanism combined with autoencoder neural network is proposed. The fault signal is decomposed by wavelet and the subband energy is used as the input of the neural network, which is composed of autoencoder and fault recognition network. The input signal is compressed by an encoder, represented by a small number of features, and transmitted to the fault detection network. By extracting features and training fault signals, the network structure can effectively identify fault categories. Simulation experiments based on IEEE34 show that the fault recognition rate of this method is over 98%, and it can detect distribution network faults effectively under the condition of noise, and has high anti-interference performance. It provides a new idea for fault detection of distribution networks and lays a foundation for a high robustness detection method.
Research on Smart Electricity Meter Based on LoRa Technology
Authors: Yang Yang , Zhang Chuang , Yan Weiwei , Liang Qinci , Xuan Minsheng , Guo Shuai
Published: March 2022

For the current wireless communication methods of smart electricity meter, the communication cannot simultaneously take into account low power consumption and long distance. In this paper, the smart electricity meter based on LoRa technology is studied, using FM3308 chip as the control core, achieving low-power and long-distance communication through LoRa technology, and the nti-interference design is carried out from both hardware and software aspects. The research content of this paper realizes the coexistence of longdistance transmission and low power consumption of smart electricity meter communication, and maintains the better anti-interference ability of smart electricity meter, which is conducive to the realization of long-distance centralized meter reading behavior and can greatly reduce the arrangement of repeaters, reduces the cost investment while lowering the design requirements and helps to promote the construction of smart grid.
Flat Currents and Solutions of the AdS
3 × S
3 Superstring
Authors: Zhang Lixia , Li Lei , Miao Zheng , Fan Qi
Published: March 2022

For the covariant K-symmetric Green-Schwarz superstring action on AdS
3 × S
3 background, we show that Cartan one-forms associated with the flat currents satisfy not only the equations of motion but also the Virasoro constraint. So the flat currents with the spectrum parameter would make for a succession of classical conserved solutions ,which have the similar inexhaustible series of classical conserved quantities.
A New Generation of Hardware-in-the-loop Simulation Technology Combined with High-performance Computers and Digital Twins
Authors: Shi Yehui , Cheng Yuqiang , Gao Yushan
Published: March 2022

Liquid rocket engines are complex equipment with long maintenance cycles and high fault diagnosis costs. Therefore, hardware-in-the-loop simulation combining software and hardware has become the best choice. A hardware-in-the-loop simulation platform framework is proposed based on a V-type development model and related digital twin technology, and the main content of the framework is introduced. Based on the development process of the platform, a certain type of liquid rocket engine is taken as the object to verify the results. The results show that the platform can well simulate the engine changes under different faults, and has versatility and high real-time performance.
An Intelligent Multi-turn Dialogue Classification Method Based on Resampling
Authors: Guo Ming , Zhang Yunju , Yang Qiang , Shen Guangyou
Published: March 2022

Intelligent multi-turn dialogue classification uses the whole text as input to predict tags. As one of the most popular research topics in dialogue system, intelligent multi-turn dialogue classification has important research significance in academia and industry. In this paper, we focus on removing redundant information from dialogue text. Multi-turn dialogue classification is essentially a text classification problem. We selects Bert as the core model of multi-turn dialogue classification in view of its strong learning and redundancy removing ability. However, Bert limits the length of its input to 512 and the length of dialogues often exceeds 512. A long text segmentation method based on resampling is presented to solve the problem of input length limitation. The resampling mechanism can also further remove the redundant information in multi-turn dialogues. Experimental results show that the proposed method outperforms all the baselines and achieves an F1 of 53.91%.
Research on Mini-EfficientDet Identification Algorithm Based on Transfer Learning
Authors: Liu Chao , Lin Shouying
Published: March 2022

In this research paper, the Chinese beehive culture in Fujian Province, China is used as the carrier, and the Mini-EfficientDet deep neural network after migration is used to identify common species at the hive door, that is, the identification of Chinese bees, wasps and cockroaches in the form of nymphs. In this paper, we define the modified model as Mini-EfficientDet by compressing the initial EfficientDet model and adding the category imbalance function, which makes it focus more on the recognition and classification of small targets while ensuring the recognition accuracy. Through the test on the MSCOCO2017 data set, it is concluded that when the backbone network adopts EfficientNet B7, it shows strong detection accuracy in detecting targets of various scales, which confirms the role of the category imbalance function proposed in this paper and the efficiency of the improved EfficientDet model. Detection accuracy. The pre-trained model is transferred to the field of beehive species detection through migration learning, that is, after the post-training of the self-collected data set, the detection accuracy of Chinese bee, cockroach, and wasp is 98.66%, 83.71%, and 82.06%. It has made sufficient algorithmic preparations for the later detection and early warning system of beehive species invasion.
Automatic Detection of Avionics Electrical Connector Pins
Authors: Zhang Xiaolin , Wu Hanqing , Wu Yanxiang , Cao Lei
Published: March 2022

Avionics electronic connectors have a wide use and play a significant role in instrumentation and aerospace system. To substitute manual detection, we propose an automatic in-station connector pin detection system based on computer vision, machine vision, deep learning, and industrial robots. This system provides a high-reliable, high-accuracy, traceable, quantifiable, and real-time detection for connector pins.
Practical Application for Reactor Installation to Reduce Harmonics Resonance of Steel Factory
Authors: Hasabelrasul Hashim , Cai Zhenjiang , Kamal Mohaned , Sun Lei , Suo Xuesong
Published: March 2022

Harmonicis one of the problems in the power system. It needs more focus due to the number of electrical devices that generate a considerable amount of harmonics. In this paper, a reactor was designed, installation and implementation for a steel factory. The installation objective is to solve harmonic resonance and reduce billing penalties for reactive power KVA by the electric power utility—technical analysis applied to the factory main panel. The ETAP software is used to discover the problem and evaluate the solution results. The power flow and harmonics analysis of an 11 kV system is modeled and implemented. Finally, the proper reactor was calculated and installation as practical to solve the harmonic and economic issues.
Design and Analysis of a New Cooling Structure for Interior Permanent Magnet Synchronous Motor with Built-in Fan
Authors: Wang Jin , Chen Lihui , Yu Zhanyang , Wang Zicheng , Li Yan
Published: March 2022

Aiming at the overheating problem of interior permanent magnet synchronous motor (IPMSM) for compressors due to the limitation of working environment, a new type of IPMSM with built-in fan based on the axial ventilation cooling structure is proposed. Firstly, an axial fan is installed inside the rotor without affecting the electromagnetic performance of motor, and the air velocity distribution and temperature distribution characteristics inside motor are analysed by computational fluid dynamics (CFD). Secondly, the influence of the position of the inlet and outlet on the heat flow distribution is analyzed. Finally, for the problem that the heat dissipation effect of the ventilation slots on casing is not obvious, the ventilation slots are removed and the air outlets are installed on front cover. And the results of heat flow characteristics show that this cooling structure is optimal.
Control Strategy of Rare Earth Permanent Magnet Synchronous Motor
Authors: Liu Xichen
Published: March 2022

Rare earth permanent magnet materials and magnetic composites help permanent magnet synchronous motor well developed. And it also has the advantages of small rotor inertia, high efficiency, high power density and high reliability. It has a good application prospect in high-performance servo system. This paper discusses the control strategy of permanent magnet synchronous motor.