bluuebunny/crossref_metadata_2025 huggingface dataset:
Erwinia amylovora (fireblight).
Authors: Vanneste Joel
Published: April 2021

The long distance spread of fire blight is a rare event which in most cases seems to be the result of plants or plant tissues being moved across the oceans. Short distance spread is the result of the characteristics of the pathogen, especially its ability to produce an exudate (bacteria embedded in exopolysaccharides) which is easily transported by wind, rain, insects or birds. This is very efficient; once the pathogen has moved into a new territory it almost always colonizes and becomes established. This is accompanied by economic losses in regions where apple, pear or loquat are grown commercially; it might prevent the survival of local cultivars and could disrupt international trade. To date fire blight has colonized most of North America, Western Europe and most of the countries around the Mediterranean Sea as well as New Zealand. Outbreaks of fire blight are irregular and difficult to control.
Sugarcane grassy shoot phytoplasma (grassy shoot of sugarcane).
Authors: Marcone Carmine
Published: April 2021

The incidence of sugarcane grassy shoot (SCGS) disease may reach up to 70% or more as is often true for ratoon crops resulting in yield losses of 40-90%, but often approaching 100% (Rishi and Chen, 1989; Viswanathan, 1997, 2001a; Rao and Dhumal, 2002; Srivastava et al., 2006).
Right-wing populism as a worldview and online practice: Social media communication by ordinary citizens between ideology and lifestyles
Authors: Krämer Benjamin , Fernholz Tobias , Husung Tobias , Meusel Julia , Voll Magdalena
Published: April 2021

Right-wing populist ideologies are expressed not only by politicians, party members or mass media actors but also by non-organised citizens on social media. On these platforms, political messages alternate with posts revealing personal lifestyles. We assume that an increasingly coherent political milieu and identity are emerging around right-wing populist worldviews that manifest themselves in social media practices and correspond with expressions of other aspects of lifestyles. A qualitative study of social media accounts of users who expressed a right-wing populist worldview was conducted. We investigate how core elements of right-wing populism are being communicated by these users, reconstruct a typical vision of society that links political concerns with users’ everyday way of life, identify political and social topics beyond the core of right-wing populism, and analyse how these different elements of online expression are held together by a specific style of thinking and communication.
Immunogenicity and efficacy of one and two doses of Ad26.COV2.S COVID vaccine in adult and aged NHP
Authors: Solforosi Laura , Kuipers Harmjan , Jongeneelen Mandy , Rosendahl Huber Sietske K. , van der Lubbe Joan E.M. , Dekking Liesbeth , Czapska-Casey Dominika N. , Izquierdo Gil Ana , Baert Miranda R.M. , Drijver Joke , Vaneman Joost , van Huizen Ella , Choi Ying , Vreugdenhil Jessica , Kroos Sanne , de Wilde Adriaan H. , Kourkouta Eleni , Custers Jerome , van der Vlugt Remko , Veldman Daniel , Huizingh Jeroen , Kaszas Krisztian , Dalebout Tim J. , Myeni Sebenzile K. , Kikkert Marjolein , Snijder Eric J. , Barouch Dan H. , Böszörményi Kinga P. , Stammes Marieke A. , Kondova Ivanela , Verschoor Ernst J. , Verstrepen Babs E. , Koopman Gerrit , Mooij Petra , Bogers Willy M.J.M. , van Heerden Marjolein , Muchene Leacky , Tolboom Jeroen T.B.M. , Roozendaal Ramon , Brandenburg Boerries , Schuitemaker Hanneke , Wegmann Frank , Zahn Roland C.
Published: April 2021

Safe and effective coronavirus disease–19 (COVID-19) vaccines are urgently needed to control the ongoing pandemic. While single-dose vaccine regimens would provide multiple advantages, two doses may improve the magnitude and durability of immunity and protective efficacy. We assessed one- and two-dose regimens of the Ad26.COV2.S vaccine candidate in adult and aged nonhuman primates (NHPs). A two-dose Ad26.COV2.S regimen induced higher peak binding and neutralizing antibody responses compared with a single dose. In one-dose regimens, neutralizing antibody responses were stable for at least 14 wk, providing an early indication of durability. Ad26.COV2.S induced humoral immunity and T helper cell (Th cell) 1–skewed cellular responses in aged NHPs that were comparable to those in adult animals. Aged Ad26.COV2.S-vaccinated animals challenged 3 mo after dose 1 with a SARS-CoV-2 spike G614 variant showed near complete lower and substantial upper respiratory tract protection for both regimens. Neutralization of variants of concern by NHP sera was reduced for B.1.351 lineages while maintained for the B.1.1.7 lineage independent of Ad26.COV2.S vaccine regimen.
Reconstruction of a single-active-electron potential from electron momentum distribution produced by strong-field ionization using optimization technique
Authors: Shvetsov-Shilovski N I
Published: April 2021

We present a method for retrieving of single-active electron potential in an atom or molecule from a given momentum distribution of photoelectrons ionized by a strong laser field. In this method the potential varying within certain limits is found as the result of the optimization procedure aimed at reproducing the given momentum distribution. The optimization using numerical solution of the time-dependent Schrödinger equation for ionization of a model one-dimensional atom shows the good accuracy of the potential reconstruction method. This applies to different ways used for representing of the potential under reconstruction, including a parametrization and determination of the potential by specifying its values on a spatial grid.
Nanoscale control of temperature operation ranges for magnetocaloric applications
Authors: Salcedo Gallo Juan Sebastián , Berger Andreas , Quintana Mikel , Restrepo Parra Elisabeth , Fallarino Lorenzo
Published: April 2021

We devised a proof-of-concept materials design that addresses the necessary requirements for magnetocaloric materials to have a constant magnetocaloric effect (MCE) over a large temperature range. For this purpose, we have fabricated epitaxial Co1−x(z)Ru
x

(z) films engineered to have a triangular gradient in exchange strength J along the thickness. Different from homogeneous Co1−x
Ru
x
layers, where the maximum value of magnetic entropy change ΔS
m falls rapidly with temperature away from the ferromagnetic (FM)–paramagnetic (PM) phase transition, the Co1−x(z)Ru
x

(z) graded structures exhibit high MCE over a large temperature range, leading to an improved cooling capacity. Theoretical modeling results confirm the enhanced temperature range and highlight a core aspect of our exchange graded materials approach, namely the ability to control and manipulate magnetism at nanoscale dimensions. As we demonstrate, this control is reliant on the fact that the temperature driven PM–FM phase transition does not occur in the entirety of the material system but only in well-defined nanoscopic regions of our samples at any given temperature, enabling us to significantly extend the useful temperature range for magneto-caloric utilization.
Defect passivation in CH3NH3PbI3 films using alkali metal fluoride additives for highly efficient perovskite solar cells
Authors: Xu Pengyu , Piao Hongjing , Liu Shuai , Hu Haihua , Ding Jiajie , Bao Jiahui , Wang Peng , Wu Xiaoping , Xu Lingbo , Lin Ping , He Haiyan , Cui Can
Published: April 2021

Solution-processed organic/inorganic hybrid halide perovskites are a class of very promising photovoltaic materials because of their extraordinary optoelectronic properties. However, numerous intrinsic defects within perovskite films limit the performance enhancement of perovskite solar cells (PSCs). Herein, we introduce three different alkali metal fluoride additives into the perovskite precursor to modulate the defect behaviors. The addition of alkali metal fluorides, especially potassium fluoride (KF), significantly passivates grain boundaries and point defects within bulk perovskite films, contributing to increased carrier lifetime and reduced defect state density. By optimizing the concentration of additives, the PSC device with 1% KF added has realized a significantly enhanced power conversion efficiency of 20.11%, and ignorable hysteresis.
Radon protection in apartments using a ventilation system wireless-controlled by radon activity concentration
Authors: Dehnert Jörg , Altendorf Diana , Trabitzsch Ralf , Grünewald Hannes , Geisenhainer Ralph , Oeser Veikko , Streil Teresa , Weber Louis , Schönherr Bernd , Thomas Joachim , Forner Katrin , Alisch-Mark Mandy , Weiss Holger
Published: April 2021

The new German Radiation Protection Act (StrlSchG) of 31 December 2018 established a reference value of 300 Bq m−3 for the annual average radon activity concentration in buildings with recreation and living rooms, as well as in workplaces. It is expected that the reference value will be exceeded in a vast number of buildings throughout Germany and that radon protection measures will become indispensable. A simple and inexpensive radon protection measure for existing buildings is ventilation. In the scope of a joint project, ventilation systems with zone control and heat recovery are to be extended by the control parameter radon activity concentration. A highly sensitive, miniaturized radon monitor will be developed for this purpose, which can be integrated wirelessly into ventilation systems. Radon measurements were carried out in 13 apartments of an unoccupied heated apartment block in Germany over a period of three weeks in the wintertime. High radon activity concentrations were found on all three floors. The maximum values were 14000 Bq m−3 on the first floor, 6000 Bq m−3 on the second floor, and 2000 Bq m−3 on the third floor. Ventilation experiments were carried out in an apartment with high radon activity concentration. Two decentralized ventilation systems with heat recovery were installed in each of the two opposite outside walls. The controlling device of the system was activated wirelessly depending on the radon activity concentration. The radon activity concentration was reduced from 8000 Bq m−3 to 800 Bq m−3 in a first experiment in the living room.
Enhancement of ferroelectricity and homogeneity of orthorhombic phase in Hf0.5Zr0.5O2 thin films
Authors: Zou Zhengmiao , Tian Guo , Wang Dao , Zhang Yan , Wang Jiali , Li Yushan , Tao Ruiqiang , Fan Zhen , Chen Deyang , Zeng Min , Gao Xingsen , Dai Ji-Yan , Lu Xubing , Liu J-M
Published: April 2021

By adoption of a high permittivity ZrO2 capping layer (ZOCL), enhanced ferroelectric properties were achieved in the Hf0.5Zr0.5O2 (HZO) thin films. For HZO thin film with 10 Å ZOCL, the 2P

r
value can reach as high as ∼43.1 μC cm−2 under a sweep electric field of 3 MV cm−1. In addition, a reduced coercive field of 1.5 MV cm−1 was observed, which is comparable to that of HZO with metallic CL. Furthermore, the homogeneity of ferroelectric orthorhombic phase in HZO films was observed to be clearly increased, as evidenced by nanoscale piezoelectric force microscopy measurements. These results demonstrate that ZOCL is very favorable for high performance ferroelectric HZO films and their future device applications.
Learning non-local perfusion textures for high-quality computed tomography perfusion imaging
Authors: Li Sui , Zeng Dong , Bian Zhaoying , Li Danyang , Zhu Manman , Huang Jing , Ma Jianhua
Published: April 2021

Background. Computed tomography perfusion (CTP) imaging plays a critical role in the acute stroke syndrome assessment due to its widespread availability, speed of image acquisition, and relatively low cost. However, due to its repeated scanning protocol, CTP imaging involves a substantial radiation dose, which might increase potential cancer risks. Methods. In this work, we present a novel deep learning model called non-local perfusion texture learning network (NPTN) for high-quality CTP imaging at low-dose cases. Specifically, considering abundant similarities in the CTP images, i.e. latent self-similarities within the non-local region in the CTP images, we firstly search the most similar pixels from the adjacent frames within a fixed search window to obtain the non-local similarities and to construct non-local textures vector. Then, both the low-dose frame and these non-local textures from adjacent frames are fed into a convolution neural network to predict high-quality CTP images, which can help better characterize the structure details and contrast variants in the targeted CTP image rather than simply utilizing the targeted frame itself. The residual learning strategy and batch normalization are utilized to boost the performance of the convolution neural network. In the experiment, the CTP images of 31 patients with suspected stroke disease are collected to demonstrate the performance of the presented NPTN method. Results. The results show the presented NPTN method obtains superior performance compared with the competing methods. From numerical value, at all dose levels, the presented NPTN method has achieved around 3.0 dB improvement of average PSNR, an increase of around 1.4% of average SSIM, and a decrease of around 4.8% of average RMSE in the low-dose CTP reconstruction task, and also has achieved an increase of around 3.4% of average SSIM and a decrease of around 61.1% of average RMSE in the cerebral blood flow (CBF) estimation task. Conclusions. The presented NPTN method can obtain high-quality CTP images and estimate high-accuracy CBF map by characterizing more structure details and contrast variants in the CTP image and outperform the competing methods at low-dose cases.
Ultra-sensitive passive wireless sensor exploiting high-order exceptional point for weakly coupling detection
Authors: Zeng Chao , Zhu Kejia , Sun Yong , Li Guo , Guo Zhiwei , Jiang Jun , Li Yunhui , Jiang Haitao , Yang Yaping , Chen Hong
Published: April 2021

Since the quantum concept of parity-time (PT) symmetry has been introduced into the conventional inductor–capacitor resonance, strategies based on exceptional points (EP) based strategies redefine our understanding of sensitivity limitation. This considerable enhancement of sensitivity originated in exploration of the non-Hermitian physics in photonics, acoustics and electronics, which exhibits a substantial application to the miniaturization of implanted electronic sensors in medicine field. By continuously accessing the EP, the spectral response of reader ∆ω follows a dependency of Δω ∼ κ
2/3 to a weakly coupling rate (|κ| ≈ 0), which may approach the theoretical limit of sensitivity in a second-order EP system. In this paper, we experimentally demonstrate a high-order (higher than second-order) PT symmetric system for weak coupling detection, in which a third-order EP can be employed to fulfill the sensitivity of Δω ∼ κ
1/2. Particularly, we introduce the incoming wave as an effective gain to balance the loss and obtain a pair of purely real eigenfrequencies. There are absence of imaginary parts despite corresponding real parts shifts dramatically by using a neutral resonator, without a broadening of the reflection spectrum so that maintaining a high resolution on the sensitivity. This work may reveal the physical mechanics of a small perturbation at a high-order EP and promote applications in implanted medicine devices.
Impact of uniform and non-uniform heated rods on free convective flow inside a porous enclosure: finite element analysis
Authors: Yasin Amna , Ullah Naeem , Saleem S , Nadeem Sohail , Al-Zubaidi A
Published: April 2021

A numerical study of laminar natural convective flow in a porous rectangular cavity having two heated rods is performed in this article. Both heated rods are placed in the middle of the cavity. Further, it is assumed that the flow and isothermal contours are influenced by permeable medium. Physical laws transform this physical setup into the mathematical form, which is expressed as partial differential equation. Finite element method is adopted to get the solution of these partial differential equations, the results against various flow controlling variables are presented in contour plots and line graphs. Results illustrate that in the case of non-uniform heating, the heat transfer rate is suppressed with the enhancement Rayleigh parameter as compared to uniform heating. In addition, with the increase in heated length of rods, flow field gets stronger due to stronger buoyancy effects. Moreover, the velocity distribution and Nusselt number are enhanced with the rise of permeability of porous medium.
Thermodynamic and magnetocaloric properties of a triple-layer graphene-like structure
Authors: Sun Lei , Lv Dan , Wang Wei , Gao Zhong-yue , Li Bo-chen
Published: April 2021

Thermodynamic and magnetocaloric properties of the triple-layer graphene-like structure with mixed spin-3/2 and spin-5/2 have been reported by applying the Monte Carlo simulation. We found that for such system, various exchange couplings or external magnetic field affect greatly the magnetic behaviors and magnetocaloric effect. For example, the value of magnetization increases and the system becomes more stable with increasing the exchange couplings or external magnetic field. Besides, there exists a peak in each magnetic entropy change curve near the critical temperature. The value of it increases with decreasing exchange couplings or increasing the external magnetic field. In addition, when the exchange couplings decreases or the external magnetic field increases, the relative cooling power enhances. Finally, the hysteresis behaviors have also been investigated in detail.
Inverted V-shaped evolution of superconducting temperature in SrBC under pressure*
Authors: Zhao Ru-Yi , Yan Xun-Wang , Gao Miao
Published: April 2021

Based on density functional first-principles calculations and anisotropic Eliashberg equations, we have investigated the electronic structure, lattice dynamics, and phonon-mediated superconductivity in newly synthesized layered compound SrBC under pressure. Different from LiBC and MgB2, our calculations surprisingly reveal that SrBC is isotropic in compressibility, due to the accumulation of substantial electrons in the interstitial region. We find that the Sr phonons strongly couple with B-2p
z
orbital and the interstitial states, giving rise to a two-gap superconductivity in SrBC, whose transition temperature shows an inverted V-shaped dependence on pressure. The maximal transition temperature is about 22 K at 50 GPa. On both sides of 50 GPa, the transition temperature exhibits quasi-linear variation with positive and negative slopes, respectively. Such a variation of transition temperature is infrequent among phonon-mediated superconductors. The competition between enhanced electron–phonon matrix element and hardened phonons plays an essential role in governing the behavior of the critical temperature.
Exclusive and dissociative J/ψ production with collinear-improved Balitsky-Kovchegov equation *
Authors: Zhang Shiyi , Cai Shaohong , Xiang Wenchang , Cai Yanbing , Zhou Daicui
Published: April 2021

We extend the hotspot model to include the virtuality dependence and use it to study the exclusive and dissociative

production combined with the dipole amplitude in the target rapidity representation. We determined that virtuality takes effect on a number of hotspots, thus providing a better description of the

production data at HERA. The collinear improved Balitsky-Kovchegove equation in the target rapidity representation is numerically solved and used to fit the

experimental data with a series of hotspot sizes. We infer that virtuality significantly influences the number and size of hotspots. The expression

resulting from the fit with the collinear improved dipole amplitude in the target rapidity representation is more reasonable than the corresponding

originating from the leading order fit, which indicates that the collinear improved evolution equation in the target rapidity representation can provide a relatively good depiction of the exclusive and dissociative HERA data.
AdS/Deep-Learning made easy: simple examples *
Authors: Song Mugeon , Oh Maverick S. H. , Ahn Yongjun , Kima Keun-Young
Published: April 2021

Deep learning has been widely and actively used in various research areas. Recently, in gauge/gravity duality, a new deep learning technique called AdS/DL (Deep Learning) has been proposed. The goal of this paper is to explain the essence of AdS/DL in the simplest possible setups, without resorting to knowledge of gauge/gravity duality. This perspective will be useful for various physics problems: from the emergent spacetime as a neural network to classical mechanics problems. For prototypical examples, we choose simple classical mechanics problems. This method is slightly different from standard deep learning techniques in the sense that we not only have the right final answers but also obtain physical understanding of learning parameters.
Prognosis of stroke upper limb recovery with physiological variables using regression tree ensembles
Authors: Carino-Escobar Ruben I , Valdés-Cristerna Raquel , Carrillo-Mora Paul , Rodriguez-Barragan Marlene A , Hernandez-Arenas Claudia , Quinzaños-Fresnedo Jimena , Arias-Carrión Oscar , Cantillo-Negrete Jessica
Published: April 2021

Objective.This study assesses upper limb recovery prognosis after stroke with solely physiological information, which can provide an objective estimation of recovery.Approach.Clinical recovery was forecasted using EEG-derived Event-Related Desynchronization/Synchronization and coherence, in addition to Transcranial Magnetic Stimulation elicited motor-evoked potentials and upper limb grip and pinch strength. A Regression Tree Ensemble predicted clinical recovery of a stroke database (n= 10) measured after a two-month intervention with the Fugl-Meyer Assessment for the Upper Extremity (FMA-UE) and the Action Research Arm Test (ARAT).Main results.There were no significant differences between predicted and actual outcomes with FMA-UE (p= 0.29) and ARAT (p= 0.5). Median prediction error for FMA-UE and ARAT were of 0.3 (IQR = 6.2) and 3.4 (IQR = 9.4) points, respectively. Predictions with the most pronounced errors were due to an underestimation of high upper limb recovery. The best features for FMA-UE prediction included mostly beta activity over the sensorimotor cortex. Best ARAT prediction features were cortical beta activity, corticospinal tract integrity of the unaffected hemisphere, and upper limb strength.Significance.Results highlighted the importance of measuring cortical activity related to motor control processes, the unaffected hemisphere’s integrity, and upper limb strength for prognosis. It was also implied that stroke upper limb recovery prediction is feasible using solely physiological variables with a Regression Tree Ensemble, which can also be used to analyze physiological relationships with recovery.
Surface modification of carbon dots by UV laser radiation
Authors: Stepanova M , Dubavik A , Skurlov I , Zakharov V , Rogach A
Published: April 2021

Carbon dots have been modified using UV irradiation (405 nm laser light). UV irradiation of carbon dots has led to various changes in optical properties, which in turn means photomodification of the carbon dots surface. With an increase in light transmission, we have obtained the increasing intensity of photoluminescence and a blue shift by the laser irradiation of the carbon dots. The proposed method can help to adapt and improve the optical properties of carbon dots and can be used in applications, for example, in the optical encryption field.
Research on Resistance Characteristics of the Self-circulating Evaporative Cooling System for Traction Transformer
Authors: Yan Jing , Xiong Bin , Wen Zhiwei , Liu Ding
Published: April 2021

Compared with the tradition cooling technology, the evaporative cooling technology has the advantage of energy-saving, safety and reliability. So a self-circulating evaporative cooling structure was proposed. The narrow flow channels were designed between disk-type windings. The evaporative coolant flows in the narrow flow channels and takes away the heat loss through phase transition. In this paper the resistance characteristics of the system were studied through experiment based on the 900kVA transformer prototype.
A Study on Key LPWAN Technologies
Authors: Xu Zhiwei , Ni Jie
Published: April 2021

In the ever-changing world of technology, various communication technologies have penetrated people’s daily lives, which has greatly improved people’s work efficiency and quality of life. By means of the Internet and various LAN technologies, users can remotely control their smart home appliances. In addition, the commercial use of 5G networks has contributed to the integration of communication technologies with people’s work and life. Meanwhile, each communication technology has its own advantages and disadvantages. For wireless network technologies, distance and power consumption are always contradictory. LPWAN (Low-Power Wide-Area Network) is a wireless network technology designed to allow long-range communication with low power consumption. Therefore, this paper studied key LPWAN technologies with a focus on the LoRa technology.
Research on Container-Oriented Isolation Control Technology
Authors: Zhao Baohua , Wang Zhihao , An Ningyu , Ren Chunhui
Published: April 2021

Container technology has a series of advantages such as low physical resource consumption, fast startup speed, high concurrency, and can run in a variety of environments. It is widely used in scenarios such as big data and cloud computing. Container technology has certain advantages in performance, but there are some shortcomings in security. The container technology shares the kernel with the host, and its security mainly depends on the host. Once the attacker breaks through the host’s defense, he can easily access the files deployed in the container, steal or tamper with the file data, and cause losses to users and users. In response to the above problems, this paper proposes a container-oriented isolation control technology, which realizes further isolation of files inside the container by adding domain names to programs and files. If the program domain name matches the file part, the files in the current container cannot be accessed, and the security of the files in the container can be effectively ensured after the host is compromised.
Simulation analysis on vibration characteristics of 220kV vertically arranged double bundled conductors
Authors: Xu Zhiqing , Gao Fan , Wang Lihuan , Ren Yaning
Published: April 2021

In order to analyze the adhesion vibration characteristics of vertically arranged double bundled conductors, the vibration equation of adhesion conductor under the coupling action of aerodynamic force and electromagnetic force is established. Firstly, the electromagnetic force on the conductor with different splitting spacing is simulated by COMSOL software. Then, based on the Runge-Kutta numerical calculation method and the vibration mathematical model, the displacement time history curve and amplitude value of the adhesive wire under different wind speed, span and initial spacing are obtained. Finally, a 220kV laboratory model is built, and the real-time monitoring of the wire vibration data is carried out to verify the accuracy of the mathematical model and simulation results. The results show that the coupling effect of aerodynamic force and electromagnetic force is the main reason for the vibration of the wire. The larger the aerodynamic force and electromagnetic force, the larger the amplitude of the wire.
Power System State Estimation Based on PLS-ELM
Authors: Guo Yang , Zhang Yongmei , Fang Rui , Zhao Kui , Sha Yuanyuan
Published: April 2021

In order to effectively improve the computational accuracy and robustness of state estimation, a power system state estimation method based on partial least square (PLS) and extreme learning machine (ELM) is proposed in this paper, which combines artificial intelligence technology with grid data. In order to solve the problem of strong correlation between measurements, PLS is used to extract important information and select variables for each measurement, and the optimal variables are input into the ELM model, thus the PLS-ELM model of state quantities is established. Finally, this method is compared with other methods. Experimental results show that the proposed method reduces the complexity of the model, and has high estimation accuracy and strong robustness.
Design of multi-ellipse broadband metamaterial absorber
Authors: Li Can , Zhou Kun , Cheng Qiang
Published: April 2021

In this paper, two types of ellipse-pattern broadband metamaterial absorbers with high absorptivity are designed and analyzed. The single-ellipse periodic absorber can achieve more than 90% absorption in the range of 8.8 to 12.5 μm, and the average absorption in this range is 96.5%. Further exploration of its electromagnetic field’s distribution revealed that the coupling of propagating surface plasmon resonance and localized surface plasmon resonance is responsible for its character. An optimized four-ellipse periodic absorber can achieve 89.5% average absorption in the range of 8 to 15 μm, and the absorption is insensitive to the incident angle. The variations of absorption of the absorber under different polarization and incident angles are also discussed. This design has potential application value in uncooled infrared detectors and other fields.
Comparative Study on Performance of Aeronautical ISG Based on Brushless Synchronous Generator and PMSG
Authors: yan Li , xuejun Su , di Liu
Published: April 2021

In this paper, the simulation analysis and research on the starting and generating system based on two-stage brushless synchronous motor and permanent magnet synchronous motor are respectively carried out, and the brushless synchronous motor AC/DC mixed excitation scheme is proposed. The starting operation adopts vector control, and the output voltage precision is improved by adjusting the excitation voltage of the exciter. A permanent magnet synchronous motor starting and generating system is constructed, and the control of starting and generating is realized by using vector control based on SVPWM, the results show that the permanent magnet synchronous motor has fast starting speed, good dynamic and static performance, high power supply quality and simple hardware composition, which reduces the complexity of the control system and is convenient for engineering implementation.
Research on control method of three-phase inverter based on LQR optimal tracking control
Authors: Lei Kang , Shao Ying , Zhang Yinfeng , Sun Pan , Wang Kongxian
Published: April 2021

According to the linear quadratic optimal control principle, the idea of optimal tracking control is applied to the three-phase inverter control system, which can effectively improve the output characteristics of the system. Based on the establishment of mathematical model, the nonlinear load and load mutation are regarded as the uncertain factors affecting the performance of three-phase inverter, and the parameter optimization design of state feedback and input feedforward is carried out based on the linear quadratic optimal control method. The simulation results show that the LQR optimal tracking control can better adapt to the adverse effects of nonlinear load and load mutation than the traditional quasi-PR control, and the system has good harmonic performance, dynamic performance and the ability to resist load disturbance.
Sdgan: Improve Speech Enhancement Quality by Information Filter
Authors: Guo Xiaozhou , Liu Yi , Mao Wenyu , Li Jixing , Li Wenchang , Gong Guoliang , Lu Huaxiang
Published: April 2021

The speech denoising model based on adversarial generative network has achieved better results than the traditional machine learning model. In this paper, for the short cut connection in the generator, we discuss its influence on the information transfer between encoder and decoder, and propose SDGAN at target. SDGAN sets linear and convolution filters in the short cut connection which adaptively learn the optimal information processing. The information filter still enables the generator to solve the gradient vanishing problem, and it can also avoid information redundancy and improve expression ability. In addition, SDGAN replaces the L1 regularization term in loss function with the L2 regularization term, which not only makes the output speech of the generator closer to the clean speech, but also avoids sparsity. In the experiments, SDGAN significantly performs better than other traditional GAN in five performance metrics (such as PESQ), and the effect of convolution filter is better than that of linear filter.
Multimodal Fusion for Image and Text Classification with Feature Selection and Dimension Reduction
Authors: Liu Xinran , Wang Zhongju , Wang Long
Published: April 2021

Internet has become an important information platform, and it is very important to accurately understand the multimedia information of the Internet. In this paper, our main task is to do classification based on pictures and texts collected from the Internet, which is a classification problem of multimodal fusion in practice. However, when multimodal data is put together, there may occur the dimension disaster problem. We apply feature selection (FS) and dimension reduction (DR) in feature levels both in later fusion and early fusion to solve this problem. The classification accuracies in different models obtain improvements in different levels respectively. We also discuss the relation between single modals and multimodal in later fusion. In our experiments, images and text can be classified by multimodal models under FS/DR, and of which with the help the multimedia information from the Internet can be analysed better to help enterprises provide better services and products, and then carry out better network marketing and promotion.
Analysis on application scheme of electronic fence technology in power grid infrastructure project based on Beidou Navigation Positioning Technology
Authors: Zheng Chenhong , Zhang Chengwei , Liu Qin , Chen Binqian , Ye Minquan , Ma Sheng
Published: April 2021

This paper takes the electronic fence technology of power grid infrastructure project based on Beidou Positioning Technology as the research object, summarizes the use situation and characteristics of this type of electronic fence technology, carries out technical and economic comparison, comprehensively considers the different use needs in the whole life cycle process of substation project infrastructure construction, operation and maintenance, expansion and technological transformation, and considers the purchase cost, installation difficulty, etc. This paper summarizes the technical advantages and engineering pilot application experience of this type of electronic fence technology. Taking one 220kV substation construction project as an example, this paper comprehensively considers other types of electronic fence technology, carries out technical analysis and economic comparison, and provides guidance for the deepening application of electronic fence technology in power grid infrastructure project based on Beidou Positioning Technology in the future.
A Graph Neural Network for superpixel image classification
Authors: Long Jianwu , yan Zeran , chen Hongfa
Published: April 2021

The classification of superpixel images by graph neural networks has gradually become a research hotspot. It is a crucial issue to embed super-pixel images from lowdimensional to high-dimensional so as to turn complex image information into graph signals. This paper proposes a method for image classification using a graph neural network (GNN) model. We convert the input image into a region adjacency graph (RAG) composed of superpixels as nodes, and use residual and concat structure to extract deep features. Finally, the loss function that increases the distance between classes and compactness within classes is used as supervision. Experiments have been tested with different numbers of superpixels on multiple datasets, and the results show that our method has a great performance in superpixel images classification.
Research on the communication mechanism between entities based on end-to-end credible state assessment
Authors: Zhao Baohua , Wang Zhihao , An Ningyu , Ren Chunhui
Published: April 2021

In the information age, with the development of internet technology, there are more and more various business services, at the same time, network security issues are also increasing. However, traditional protection methods are gradually hard to cope with the complex network environment. Aiming at the credible connection establishment and data communication problems that need to be solved urgently in the credible network, an interentity communication mechanism based on end-to-end credibility assessment is proposed. This mechanism combines trusted computing with network access control mechanisms, integrates network access authority control technology, server identity authentication technology, communication subject measurement technology and network link transparent encryption technology, adopts real-time monitoring of terminal status, dynamic adjustment of access authorities, optimized network access control mechanism and data transmission method, to against security issues of the network communication. After security analysis, this mechanism improves the security of the connection and communication between the terminal and the network. It can effectively avoid security threats to information systems, and make the service of the information system safe and reliable.
The Design of a Virtual Reality Image Distortion Method for mobile devices
Authors: Wu Guanlin , Bao Weidong , Cao Jiang , Zhu Xiaomin , Ping Yang , Song Jia , xin Quan
Published: April 2021

How to predict a more accurate next frame according to the current frame is still a problem. In this study, a method of generating intermediate frames in VR is proposed, which can effectively reduce the image jitter in VR games and increase the user experience; on the other hand, the inverse matrix method proposed in this study has a small amount of calculation and a fast calculation speed, and can complete the calculation in a short time. Therefore, this method can help us to complete the insertion of frames in the specified time. In this paper, firstly, the algorithm is constructed based on the principle of inverse matrix, and then the simulation experiment is carried out. The experimental results show that the scheme is a viable and effective solution.
Cause analysis and improvement of 500 kV capacitive bushing end shield fault
Authors: Yang Shaoyuan , Yang Xuefei , Li Yinghong
Published: April 2021

Aimed at solving the problem of the end shield fault of 500 kV capacitive bushing which happened frequently in the main power grid in recent time, two faults are taken as examples to analyze the fault characteristics and reasons of the spring cap type end shield devices. On that basis, effective revention measures and modification schemes for the spring cap type end shield devices of 500 kV capacitive bushing are proposed from perspectives of the equipment security operation and maintenance, and personal safety.
Research on dynamic route selection method of D2D communication under multi hop transmission
Authors: Qu Huijie , Qiu Ming
Published: April 2021

In order to find the best path in wireless sensor networks, a dynamic energy-saving routing strategy based on multi hop transmission is proposed. The dynamic state transition optimization rules are designed to increase the search probability of new nodes reasonably, so as to find the global optimal solution quickly and effectively, so as to save the search time, increase the optimal path search probability and prolong the network survival time. Simulation results and analysis show that the dynamic route selection method of D2D communication under multi hop transmission greatly increases the search probability of the global optimal solution, achieves the global optimal solution quickly and effectively, saves the energy consumption of nodes, and is conducive to extending the network survival time.
Research on Tibetan-Chinese neural network machine translation with few samples
Authors: Sun Yidong , Yong Cuo
Published: April 2021

Machine translation is an important task in natural language processing, and the study of Tibetan-Chinese neural machine translation is of profound significance in promoting Tibetan-Chinese scientific and cultural exchanges and the development of education and culture. In this paper, we investigate the performance of these techniques and methods on Tibetan-Chinese NMT with few samples by using deactivated word lists, data augmentation (back translation), pre-training models (ELMO), and attention mechanisms for the techniques and methods widely used in NMT, using seq2seq and Transformer models as the baseline, and finally, the BLEU value of Tibetan-Chinese NMT is increased from the initial 5.53 to 19.03.
Design Challenges in Wikipedia-style Spotlight Annotation
Authors: Pang Kunyuan , Tang Jintao , Li Xinyi , Li Xiao , Li Shasha , Wang Ting
Published: April 2021

Wikipedia has set up a manual of style to provide the Wikipedian with guidelines to create links as spotlights in articles to help readers’ understanding. Wikification is coined following Wikipedia’s style guide as a task of automatically detecting mentions and linking to entities in plain-text articles. However, existing methods rely heavily on the mention-entity dictionary and focus on in-map entity precision. Some popular methods are limited to Named Entities. The comparison on the outcome of spotlight annotation is insufficient. We investigate the design challenges for constructing automatic annotating in Wikipedia-style systems. A dataset is built simulating real-world spotlight annotation problems in both the preparing and application phases. Popular methods are compared along with a straightforward framework we propose called WikiER. Experiments show that the performance of currently available systems varies a lot. It is important to train on the task-specific data. The best performance is achieved by WikiER.
One scheme of stabilization and sample-data control for T-S fuzzy time-delay systems
Authors: Wang Wenhao , Zhu Hong , Zhong Shouming , Shi Kaibo
Published: April 2021

In this article, a refined Lyapunov functional is proposed to study the stabilization problem for Takagi-Sugeno (T-S) fuzzy systems with time delays. Considering both the time-varying delays of the system and the constant delays of the part of sample-data control loop, the refined Lyapunov function in this paper makes it more practical in actual sampling control pattern compared with some existing research. Some techniques of dealing the linear matrix inequalities (LMIs) are used to derive the less conservative criteria and an example is presented in the end to prove the availability of the work.
The forecast of household power load based on genetic algorithm optimizing BP neural network
Authors: Liu Hengchao
Published: April 2021

In view of the fact that power load forecasting is increasingly becoming an important part of power system planning and power dispatching, this paper proposed a forecasting method based on genetic algorithm optimizing BP neural network and applied it to household power load forecasting. First of all, the original data were pre-processed by factor analysis to eliminate the correlation between variables, and then the household load from January 1st to March 22nd was predicted by using BP and GA-BP models respectively. The author obtained the predicted results in the next 5 days summing to 120 hours and utilized MAPE and RMSE to compare their prediction errors quantitatively. The predicted results of the calculation example are in good agreement with actual values. Therefore it is demonstrated that the BP neural network optimized by genetic algorithm has better forecasting effects, which can provide reference for residential and municipal short-term load forecasting.
A Reusable Test Case Management System Based on Exploratory Testing
Authors: Yu Jiujiu , Zhang Jishan , Chen Yun , Wu Ning , Mei Yingying , Zhang Deqing , Zhu Canglu , Zhu Lili
Published: April 2021

The research is mainly based on the concept of technologies of software exploratory testing, Questing Patterns (Q-Patterns) and reusable test case, taking a reusable test case as an example, this study is devoted to the development of a feasible reusable test case management system based on exploratory testing in rapid prototype development method, which the process of design, storage, reuse and management of test cases could be implemented positively in the first system version. Furthermore, further work for technical improvement in the next version of this system is put forward.
A method based on cuckoo search for optimal network reconfiguration
Authors: Gao Zhengzhong , Xu Yujuan , Li Zongfu , Sun Yuchen , Liu Guangjie
Published: April 2021

The optimal reconfiguration of the distribution network doesn’t require any cost and becomes an effective technique for reducing power loss. So this paper proposes an efficient cuckoo search algorithm for this problem. First, the mapping relationship between the cuckoo search algorithm and the distribution network is established; secondly, the algorithm generates the initial population based on the set of feasible solutions; finally, algorithm updates the nest position by the Lévy flight and nest parasitic behavior. A variable domain search algorithm is introduced to improve for the shortcomings of the cuckoo search algorithm in the process of solving the distribution network reconfiguration problem. Finally, it is verified that the algorithm has the ability to quickly solve the optimal solution by the IEEE33 model simulation analysis.
Construction of Scene Tibetan Dataset Based on GAN
Authors: Zhang Guowei , Wang Weilan , Zhao Penghai , Li Jincheng
Published: April 2021

For the research of Tibetan scene text detection and recognition, it is time-consuming and laborious to collect and annotate natural scene data labels manually. Therefore, artificial synthetic data is of great significance for promoting relevant work. This paper focuses on the study of replacing other languages in the scene with Tibetan, while maintaining the style of the original text. We decompose the problem into three sub-networks: text style transfer network, background inpainting network and fusion network. Firstly, the text in the foreground image is replaced by the text style transfer network to generate the foreground image. Then the background inpainting network erases the original text in the style image, and uses the surrounding information around the text to fill the text area to generate the background image. Finally, the generated foreground image and background image are used to generate the target image by the fusion network. We experimented with conversions from English to Tibetan and English to English to verify the generalization and robustness of the network. Experimental results show that its accuracy (SSIM, PSNR) on some datasets (SVT, ICDAR 2013) has been improved to some extent.
Pedestrian detection based on one-stage YOLO algorithm
Authors: Zuo Xun , Li Jiaojun , Huang Jie , Yang Fan , Qiu Tian , Jiang Yang
Published: April 2021

Pedestrian detection is mostly used in autonomous driving scenarios, which require high real-time detection. Most of the existing algorithms are based on Two-Stage detection, with poor real-time performance. This paper proposes a pedestrian detection system based on One-Stage, and uses One-Stage-based YOLO-Tiny, YOLO and YOLO-SPP algorithms to test and analyze the system in the scene of detecting pedestrians of different sizes. The results show that YOLO and YOLO-SPP have high average confidence, and YOLO-Tiny has a fast detection speed, which is suitable for fast detection scenarios.