bluuebunny/crossref_metadata_2025 huggingface dataset:
High-mobility electron gas in Sr2TiO4/SrTiO3 heterostructure engineered by vertical Ruddlesden–Popper faults
Authors: Zhang T. T. , Li J. Y. , Yang J. F. , Gao T. Y. , Sun H. Y. , Gu Z. B. , Deng Y. , Nie Y. F.
Published: December 2022

High-mobility electron gases in SrTiO3-based heterostructures have been mainly synthesized on single TiO2 terminated SrTiO3 substrates. Here, we show a high-mobility electron gas observed in a Sr2TiO4/SrTiO3 heterostructure based on an untreated SrTiO3 substrate with mixed termination, showing the mobility value up to 28 000 cm2 V−1 s−1 at 2 K. SrO–SrO vertical Ruddlesden–Popper faults in the Sr2TiO4 film provide escape channels for oxygen atoms under high temperatures, enabling the as-grown tuning of oxygen vacancies in the SrTiO3 layer during film deposition and reversible after-growth modulation in a thermal annealing process.
Studying the micromechanism of water injection to suppress coal and gas protrusion
Authors: Lun Jiayun , Han Haoliang , Fang Xinliang , Ding Junling , Jia Nan
Published: December 2022

To explore the adsorption mechanism of CH4 and H2O molecules on the surface of low-rank coal (LRC) from the microscopic point of view, the electrostatic potential and frontier orbitals of each oxygen-containing functional group (OFGs) in LRC and adsorbent molecule, the adsorption energy, and Mulliken charge layout of CH4 molecules and H2O molecules with OFGs in LRC were investigated by density functional theory (DFT) simulation method. The results of DFT calculations showed that the order of adsorption strength of CH4 molecules on different OFGs was OCH3–LRC (-9.643 kJ/mol) > C=O–LRC (−8.625 kJ/mol) > OH–LRC (−7.241 kJ/mol) > COOH–LRC (−6.194 kJ/mol), which were all smaller than that of the C–LRC model without functionalization (−10.749 kJ/mol). The presence of OFGs reduces the adsorption strength of CH4 molecules on the surface of LRC. The order of strength of adsorption of H2O molecules on different OFGs was COOH–LRC (−69.836 kJ/mol) > OH−LRC (−46.442 kJ/mol) > C=O–LRC (−42.848 kJ/mol) > OCH3–LRC (−33.079 kJ/mol), and they were all greater than that of the C–LRC model without functionalization (−32.572 kJ/mol). The presence of OFGs improves the adsorption strength of H2O molecules on the surface of LRC. Both the LRC model modified with OFGs and the non-functionalized C–LRC model showed stronger adsorption of H2O molecules compared to that of CH4 molecules. Therefore, coal seam water injection can reduce the amount of gas gushing and mitigate coal seam gas protrusion.
Improving LIGO calibration accuracy by using time-dependent filters to compensate for temporal variations
Authors: Wade M , Viets A D , Chmiel T , Stover M , Wade L
Published: December 2022

The response of the Advanced Laser Interferometer Gravitational-wave Observatory (Advanced LIGO) interferometers is known to vary with time (Tuyenbayev et al 2017 Class. Quantum Grav.
34 015002). Accurate calibration of the interferometers must therefore track and compensate for temporal variations in calibration model parameters. These variations were tracked during the first three Advanced LIGO observing runs, and compensation for some of them has been implemented in the calibration procedure. During the second observing run, multiplicative corrections to the interferometer response were applied while producing calibrated strain data both in real time and in high latency. In a high-latency calibration produced after the second observing run and during the entirety of the third observing run, a correction requiring periodic filter updates was applied to the calibration–the time dependence of the coupled cavity pole frequency

f

c
c

. This paper describes the methods developed to compensate for variations in the interferometer response requiring time-dependent filters, including variable zeros, poles, gains, and time delays. The described methods were used to provide compensation for well-modeled time dependence of the interferometer response, which has helped to reduce systematic errors in the calibration to

<

2% in magnitude and

<

2∘ in phase across LIGO’s most sensitive frequency band of 20–2000 Hz (Sun et al 2020 Class. Quantum Grav.
37 225008; Sun et al 2021 arXiv:2107.00129 [astro-ph.IM]). Additionally, this paper shows how such compensation is relevant for astrophysical inference studies by reducing uncertainty and bias in the sky localization for a simulated binary neutron star merger.
Intelligent bearing fault diagnosis method based on a domain aligned clustering network
Authors: Zhou Huafeng , Cheng Peiyuan , Shao Siyu , Zhao Yuwei , Yang Xinyu
Published: December 2022

In recent years, intelligent fault diagnosis algorithms based on domain adaptation have provided a feasible solution to the problem of diagnosing performance degradation caused by different data distributions and a lack of target labels. However, most of the existing domain adaptation fault diagnosis algorithms are highly dependent on the label space and prior knowledge of the source and target domain, which greatly limits their application in practical scenarios. In this paper, faced with the circumstances that fault information and label space of the target mechanical device are completely unknown, a novel intelligent diagnostic method based on universal domain adaptation—the domain aligned clustering network (DACN)—is proposed. On the one hand, the number of clusters is determined by domain clustering analysis, and the public class and private class samples in both domains are identified. On the other hand, in order to achieve high accuracy of model identification on common class samples, this paper introduces the contrast domain difference and realizes class alignment between different domains by maximizing the inter-class difference and minimizing the intra-class difference. Finally, the effectiveness of the DACN is verified on the bearing datasets from Case Western Reserve University and Paderborn University. A one-dimensional class gradient activation map is calculated to explain the performance of the fault diagnosis model.
A two-stage deep-learning-based balancing method for rotating machinery
Authors: Zhong Shun , Han Hong-Xiang , Hou Lei
Published: December 2022

Purpose—balancing is essential to all rotating machinery. To make the balancing process convenient and inexpensive, new balancing technologies are needed. In this work, a two-stage deep-learning-based balancing method is proposed and validated. Design/methodology/approach—the architecture of the method is described. The whole balancing method has two stages. The first stage identifies the unbalanced force vector and the second stage identifies the correlation masses and phases from the unbalanced force series. Deep-learning-based modules can be trained using one-run response data and labeled support force data only. Findings—both numerical and experimental balancing performances are reasonable and comparative. The performances indicate that the proposed method is validated and robust. Originality—the proposed method combines deep learning technology with rotor dynamics knowledge. The proposed method achieves good performance without a weight trail process and provides a competitive approach for rotor balancing technology.
From atomistic systems to linearized continuum models for elastic materials with voids
Authors: Friedrich Manuel , Kreutz Leonard , Zemas Konstantinos
Published: December 2022

We study an atomistic model that describes the microscopic formation of material voids inside elastically stressed solids under an additional curvature regularization at the discrete level. Using a discrete-to-continuum analysis, by means of a recent geometric rigidity result in variable domains (Friedrich et al 2021 arXiv:2107.10808) and Γ-convergence tools, we rigorously derive effective linearized continuum models for elastically stressed solids with material voids in three-dimensional elasticity.
In vivo adaptive focusing for clinical contrast-enhanced transcranial ultrasound imaging in human
Authors: Robin Justine , Demené Charlie , Heiles Baptiste , Blanvillain Victor , Puke Liene , Perren Fabienne , Tanter Mickael
Published: December 2022

Objective. Imaging the human brain vasculature with high spatial and temporal resolution remains challenging in the clinic today. Transcranial ultrasound is still scarcely used for cerebrovascular imaging, due to low sensitivity and strong phase aberrations induced by the skull bone that only enable the proximal part major brain vessel imaging, even with ultrasound contrast agent injection (microbubbles). Approach. Here, we propose an adaptive aberration correction technique for skull bone aberrations based on the backscattered signals coming from intravenously injected microbubbles. Our aberration correction technique was implemented to image brain vasculature in human adults through temporal and occipital bone windows. For each subject, an effective speed of sound, as well as a phase aberration profile, were determined in several isoplanatic patches spread across the image. This information was then used in the beamforming process. Main results. This aberration correction method reduced the number of artefacts, such as ghost vessels, in the images. It improved image quality both for ultrafast Doppler imaging and ultrasound localization microscopy (ULM), especially in patients with thick bone windows. For ultrafast Doppler images, the contrast was increased by 4 dB on average, and for ULM, the number of detected microbubble tracks was increased by 38%. Significance. This technique is thus promising for better diagnosis and follow-up of brain pathologies such as aneurysms, arterial stenoses, arterial occlusions, microvascular disease and stroke and could make transcranial ultrasound imaging possible even in particularly difficult-to-image human adults.
Reconstruction of thermoacoustic emission sources induced by proton irradiation using numerical time reversal
Authors: Mast T Douglas , Johnstone David A , Dumoulin Charles L , Lamba Michael A , Patch Sarah K
Published: December 2022

Objective.Mapping of dose delivery in proton beam therapy can potentially be performed by analyzing thermoacoustic emissions measured by ultrasound arrays. Here, a method is derived and demonstrated for spatial mapping of thermoacoustic sources using numerical time reversal, simulating re-transmission of measured emissions into the medium.Approach.Spatial distributions of thermoacoustic emission sources are shown to be approximated by the analytic-signal form of the time-reversed acoustic field, evaluated at the time of the initial proton pulse. Given calibration of the array sensitivity and knowledge of tissue properties, this approach approximately reconstructs the acoustic source amplitude, equal to the product of the time derivative of the radiation dose rate, mass density, and Grüneisen parameter. This approach was implemented using two models for acoustic fields of the array elements, one modeling elements as line sources and the other as rectangular radiators. Thermoacoustic source reconstructions employed previously reported measurements of emissions from proton energy deposition in tissue-mimicking phantoms. For a phantom incorporating a bone layer, reconstructions accounted for the higher sound speed in bone. Dependence of reconstruction quality on array aperture size and signal-to-noise ratio was consistent with previous acoustic simulation studies.Main results.Thermoacoustic source distributions were successfully reconstructed from acoustic emissions measured by a linear ultrasound array. Spatial resolution of reconstructions was significantly improved in the azimuthal (array) direction by incorporation of array element diffraction. Source localization agreed well with Monte Carlo simulations of energy deposition, and was improved by incorporating effects of inhomogeneous sound speed.Significance.The presented numerical time reversal approach reconstructs thermoacoustic sources from proton beam radiation, based on straightforward processing of acoustic emissions measured by ultrasound arrays. This approach may be useful for ranging and dosimetry of clinical proton beams, if acoustic emissions of sufficient amplitude and bandwidth can be generated by therapeutic proton sources.
Effects of cavity birefringence in polarisation-encoded quantum networks
Authors: Kassa E , Hughes W , Gao S , Goodwin J F
Published: December 2022

The generation of entanglement between distant atoms via single photons is the basis for networked quantum computing, a promising route to large-scale trapped-ion and trapped-atom processors. Locating the emitter within an optical cavity provides an efficient matter-light interface, but mirror-induced birefringence within the cavity introduces time-dependence to the polarisation of the photons produced. We show that such ‘polarisation oscillation’ effects can lead to severe loss of fidelity in the context of two-photon, polarisation encoded measurement-based remote entanglement schemes. It is always preferable to suppress these errors at source by minimising mirror ellipticity, but we propose two remedies for systems where this cannot be achieved. We conclude that even modest cavity birefringence can be detrimental to remote entanglement performance, to an extent that may limit the suitability of polarisation-encoded schemes for large-scale quantum networks.
Fitting covariance matrix models to simulations
Authors: Fumagalli Alessandra , Biagetti Matteo , Saro Alex , Sefusatti Emiliano , Slosar Anže , Monaco Pierluigi , Veropalumbo Alfonso
Published: December 2022

Data analysis in cosmology requires reliable covariance matrices. Covariance matrices derived from numerical simulations often require a very large number of realizations to be accurate. When a theoretical model for the covariance matrix exists, the parameters of the model can often be fit with many fewer simulations. We write a likelihood-based method for performing such a fit. We demonstrate how a model covariance matrix can be tested by examining the appropriate χ
2 distributions from simulations. We show that if model covariance has amplitude freedom, the expectation value of second moment of χ
2 distribution with a wrong covariance matrix will always be larger than one using the true covariance matrix. By combining these steps together, we provide a way of producing reliable covariances without ever requiring running a large number of simulations. We demonstrate our method on two examples. First, we measure the two-point correlation function of halos from a large set of 10000 mock halo catalogs. We build a model covariance with 2 free parameters, which we fit using our procedure. The resulting best-fit model covariance obtained from just 100 simulation realizations proves to be as reliable as the numerical covariance matrix built from the full 10000 set. We also test our method on a setup where the covariance matrix is large by measuring the halo bispectrum for thousands of triangles for the same set of mocks. We build a block diagonal model covariance with 2 free parameters as an improvement over the diagonal Gaussian covariance. Our model covariance passes the χ
2 test only partially in this case, signaling that the model is insufficient even using free parameters, but significantly improves over the Gaussian one.
Constraint on Brans-Dicke theory from intermediate/extreme mass ratio inspirals
Authors: Jiang Tong , Dai Ning , Gong Yungui , Liang Dicong , Zhang Chao
Published: December 2022

Intermediate/Extreme mass ratio inspiral (I/EMRI) system provides a good tool
to test the nature of gravity in strong field.
Based on the method of osculating orbits,
we compute the orbital evolutions of I/EMRIs on quasi-elliptic orbits in
both Einstein's general relativity and Brans-Dicke theory.
The extra monopolar and dipolar channels in Brans-Dicke theory accelerate the orbital decay,
so it is important to consider the effects of monopolar and dipolar emissions on the waveform.
With the help of accurate orbital motion,
we generate waveform templates which include both monopolar and dipolar contributions for I/EMRIs on eccentric orbits in Brans-Dicke theory.
With a two-year observation of gravitational waves emitted from I/EMRIs by LISA,
we get the most stringent constraint on the Brans-Dicke coupling parameter ω
0 > 106.
Steady-state relation of a two-level system strongly coupled to a many-body quantum chaotic environment
Authors: Yan Hua , Wang Jiaozi , Wang Wen-ge
Published: December 2022

We study the long-time average of the reduced density matrix (RDM) of a two-level system as the central system, which is locally coupled to a many-body quantum chaotic system as the environment, under an overall Schrödinger evolution. A phenomenological relation among elements of the RDM is proposed for a dissipative interaction in the strong coupling regime and is tested numerically with the environment as a defect Ising chain, as well as a mixed-field Ising chain.
Using a high-frequency carrier does not improve comfort of transcutaneous spinal cord stimulation
Authors: Dalrymple Ashley N , Hooper Charli Ann , Kuriakose Minna G , Capogrosso Marco , Weber Douglas J
Published: December 2022

Objective. Spinal cord neuromodulation has gained much attention for demonstrating improved motor recovery in people with spinal cord injury, motivating the development of clinically applicable technologies. Among them, transcutaneous spinal cord stimulation (tSCS) is attractive because of its non-invasive profile. Many tSCS studies employ a high-frequency (10 kHz) carrier, which has been reported to reduce stimulation discomfort. However, these claims have come under scrutiny in recent years. The purpose of this study was to determine whether using a high-frequency carrier for tSCS is more comfortable at therapeutic amplitudes, which evoke posterior root-muscle (PRM) reflexes. Approach. In 16 neurologically intact participants, tSCS was delivered using a 1 ms long monophasic pulse with and without a high-frequency carrier. Stimulation amplitude and pulse duration were varied and PRM reflexes were recorded from the soleus, gastrocnemius, and tibialis anterior muscles. Participants rated their discomfort during stimulation from 0 to 10 at PRM reflex threshold. Main Results. At PRM reflex threshold, the addition of a high-frequency carrier (0.87 ± 0.2) was equally comfortable as conventional stimulation (1.03 ± 0.18) but required approximately double the charge to evoke the PRM reflex (conventional: 32.4 ± 9.2 µC; high-frequency carrier: 62.5 ± 11.1 µC). Strength-duration curves for tSCS with a high-frequency carrier had a rheobase that was 4.8× greater and a chronaxie that was 5.7× narrower than the conventional monophasic pulse, indicating that the addition of a high-frequency carrier makes stimulation less efficient in recruiting neural activity in spinal roots. Significance. Using a high-frequency carrier for tSCS is equally as comfortable and less efficient as conventional stimulation at amplitudes required to stimulate spinal dorsal roots.
Effects of drifts on scrape-off layer transport in W7-X
Authors: Kriete D.M. , Pandey A. , Perseo V. , Schmitt J.C. , Ennis D.A. , Gradic D. , Hammond K.C. , Jakubowski M. , Killer C. , König R. , Maurer D.A. , Reimold F. , Winters V. , Beurskens M.N.A. , Bozhenkov S.A. , Brunner K.J. , Fuchert G. , Knauer J. , Pasch E. , Scott E.R.
Published: December 2022

Drifts affect particle, momentum, and energy transport in the scrape-off layer (SOL) of tokamaks and stellarators, altering plasma flows and creating asymmetries between divertors. To understand how drifts affect SOL transport in the W7-X island divertor, an experiment was performed to compare plasmas with matched core parameters but opposite magnetic field directions, and therefore opposite drift transport directions. Parallel flow measurements made with coherence imaging spectroscopy are interpreted with the aid of a diagnostic forward model and a 1D simple SOL model that includes the

E

×

B

drift. In low-density plasmas (

n
‾

e

<
2
×

10

19

m−3), the poloidal

E

×

B

drift induces a large poloidal density asymmetry within the island SOL, as measured by divertor Langmuir probes. This in turn causes the parallel flow stagnation point to shift from the position halfway between targets to the X-point in the drift direction, leading to near-unidirectional flow throughout the SOL. As density increases, the effects of the poloidal

E

×

B

drift decrease substantially, resulting in a smaller density asymmetry and the development of a counter-streaming flow pattern. For the entire density range probed in this experiment (

n
‾

e

=
1.5
−
6
×

10

19

m−3), the experimental observations are more consistent with the effects of the poloidal

E

×

B

drift than the radial

E

×

B

drift.
Research on coordinated optimization of unit maintenance plan and economic dispatch in the integrated energy system
Authors: Liu Hongyu , Hu Linxian , Liu Runzhong
Published: December 2022

The medium and long-term operation of the unit is an important part of the operation of the power energy system. With the development of IES, the coupling of various energy forms such as electricity, heat and natural gas has been continuously strengthened. When a CHP unit or a gas unit is shut down, its impact will involve a variety of energy systems. Therefore, It is of great significance to formulate a reasonable annual unit combination plan and a coordinated optimization plan for the maintenance plan. First of all, starting from the coupling mechanism of the power supply, heating and gas supply of the unit, consider the relationship between each system and equipment. On this basis, taking into account the system operation constraints, unit maintenance constraints and unit operation constraints, a combined dispatch model of IES unit combination and maintenance plan including power-to-gas (P2G) and electric boiler equipment are proposed. The accuracy and effectiveness of the proposed model are verified through simulation analysis of a numerical example. The calculation example results show that the overall arrangement of the unit maintenance plan and the unit combination plan in the integrated energy system can improve the operating economy of the system; the introduction of coupling equipment such as P2G and electric boilers can effectively improve the new energy consumption rate and reduce the system operating cost.
Study on the Influence of SiO2 on Silicone Rubber Material Used in Cable Accessories
Authors: Zhao Xuefeng , Han Jiarui , Pu Lu , Duan Wei , Ju Zeli , Sun Haofei , Gao Jian
Published: December 2022

Silicone rubber is an insulating material widely used in DC cable accessories. Its interface is a weak area of insulation. Hydrated silica (SiO2·H2O) is a reinforcing agent commonly used in SR, and its main component is SiO2. Based on the theory of nano-composite dielectric, four kinds of composite silicone rubber samples with different filler contents were prepared by taking silica as the filler and liquid silicone rubber as the matrix. The properties of composite samples were tested. It is found that nano-modification can optimize the surface morphology distribution characteristics of silicone rubber, reduce the roughness, improve the tensile strength, and deepen the trap energy distribution of silicone rubber. The results of the research provide help for the design of DC cable accessories.
Arm Voltage Balance Control of a Modular Multilevel Matrix Converter with Inner and Outer Loop Double Adjustment Based on Circulating Current
Authors: Yan Tongyu , Ye Rong , Hu Yahan , Meng Yongqing , Ma Chunzhe , Duan Ziyue
Published: December 2022

This paper presents a control strategy of inter-arm voltage balance for a modular multilevel matrix converter (M3C) based on injected circulating current. The proposed method is divided into two parts, balancing the inter-arm voltage through the current control loop and the voltage control loop respectively. The strategy improves the current performance of the grid on both sides by enforcing the injected power to flow only within the nine arms, which is simple to control and suitable for various working conditions including stable operation and faults. Comparative simulation results obtained using Matlab/Simulink prove that the proposed control strategy can significantly reduce the inter-arm voltage imbalance, which demonstrates the performance and effectiveness of the strategy.
Optimal operation of RSOC integrated energy systems considering multi-state transitions
Authors: Zhang Xuzheng , Yu Haoyu , Zhao Hongfei , Zhang Zihang , Wu Kai , Zhou Jun
Published: December 2022

Reversible solid oxide fuel cells (RSOC) can realize energy storage and power generation in a compact structure, and their high-temperature operation characteristics provide the possibility for combined heat and power generation. Therefore, RSOC can be used as the node of the multi-energy flow intersection of the integrated energy system. The flexible operation mode of RSOC will greatly reduce the operation cost. However, the optimal operation of an integrated energy system including RSOC is very rare at present, so this paper establishes an integrated energy system of the electric gas network including RSOC. On this basis, this paper constructs an RSOC model, a DC power flow model and a linearized gas power flow model considering multiple operating states. Then, based on GAMS, the economic cost of a 24-20 electric gas composite network is optimized. After verifying the reliability of the model, the optimization results considering two working conditions and four working conditions are compared. It is concluded that the model considering multiple operating states of RSOC will reduce the operating cost of the system by 24%.
Research on Fault Diagnosis of Low voltage Transformer Based on Sound Feature Analysis
Authors: Huang Changbao , Cao Yang , Wang Youxiang , Zheng Yinggang , Xu Yaoliang
Published: December 2022

This paper analyzes the frequency spectrum of the sound and vibration signals during the operation of the transformer, extracts various sound characteristics for fault classification, accurately carries out real-time early warning of the operation state of the transformer, reduces the occurrence of various power consumption faults and disasters, and improves the “intelligent” means of transformer management.
Design of Backup Protective Hardware for Suspension Clamp of Electric Power Overhead Ground Wire
Authors: Feng Zhenbo , Zheng Xiaogan , Yang Yihao , Lin Li , Qian Chaofei
Published: December 2022

Aiming at the disconnection problem of power overhead ground wire caused by wind vibration or the action of power frequency short-circuit current, the newly revised “Eighteen major anti-accident measures of State Grid Corporation China” proposes that independent double string structure should be adopted in suspension clamp of overhead ground wire. Based on this, a research scheme of backup protective hardware for the suspension clamp of the overhead ground wire of the power transmission line is proposed. In this scheme, the backup protective hardware for the suspension clamp is designed and added on the premise that the original overhead ground wire-suspension clamp structure is not changed. It provides backup measures for the original suspension clamp and reduces suspension clamp heating by an electrical shunt. Finally, the mechanical failure load test and salt spray test are performed on the designed production. The results show that the designed production meets the standard and could be used in actual engineering. At the same time, the practical engineering application shows that the backup protective hardware can effectively reinforce the ground wire suspension clamp with double strings, avoiding the problem of dropping and breaking after the original clamp is broken.
Development and Application of Ionospheric Detection Technology
Authors: Sun Haiyang , Xu Liren , Wang Shengguo , Wu Yiyun
Published: December 2022

Aiming at the needs of ionospheric detection and application development, this paper mainly introduced the current development and analyzed the advantages and disadvantages of ionospheric detection technology from ground-based and space-based instruments. Meanwhile, the hot topics of ionospheric application were introduced from the three aspects of ionospheric irregularity, earthquake-ionospheric effect, and ionospheric heating, respectively. Finally, the development trend of ionospheric detection technology and its application were discussed from five aspects, and some suggestions for the future comprehensive research fields of ionospheric detection technology in China were also given.
Radar-Embedded Communication Waveform Design Based on Parameter Optimization
Authors: Liu Yiyuan , Li Baoguo , Yao Yizhou
Published: December 2022

Radar-embedded communication (REC) is a low probability of intercept (LPI) communication method that enables radar and communication to share the spectrum. Covert communication is accomplished by embedding low-power communication waveforms in high-power radar backscatter echoes. This research, by optimizing the eigenvalue matrix power exponent a of the shaped dominant projection (SDP) waveform, proposes an SDP waveform with variable eigenvalue matrix power exponent, namely SDP-a waveform. Then, the reliability of waveform communication and LPI performance are theoretically analyzed by processing gain. Finally, the simulation experiments are carried out with SDP-0.25, SDP-0.5, and SDP-0.75 waveforms as examples. The experimental results are consistent with the theoretical analysis results, indicating that the optimization of the eigenvalue matrix power exponent can meet the performance requirements of different aspects.
Research on Non-Contact Electricity Inspection Technology of Unmanned Aerial Vehicles
Authors: Wang Hui , Zhang Haitao , Chang Junting , Guo Yang , Ma Xiaolong , Wang Yongquan
Published: December 2022

The airborne non-contact electroscope developed in this paper does not need to touch the tower and can be remotely controlled to complete the electroscope. It can be widely used in the maintenance operation of various voltage levels, and the entire operation process is in line with the State Grid Corporation of China Electric Power Safe work regulations (power line part) regulations. The application of the device can effectively reduce the labor intensity of the operators, improve the operation efficiency, and ensure the safety of the operation.
Real-time Monitoring Platform for Transmission Line Trips Based on Data Mining
Authors: Diao Haoran , Zhou Zhifeng , He Xiqi
Published: December 2022

In order to improve the correctness of the judgment of transmission line tripping and the response efficiency of monitoring, data mining technology is introduced to carry out the research of real-time monitoring platforms for transmission line tripping. The required hardware of the monitoring platform includes an electromagnetic induction sensor, a clock chip, memory and the like. A hardware framework structure of the real-time monitoring platform is constructed on the basis of the hardware. Compressed sensing is carried out on a transmission line trip monitoring signal by using a data mining technology; and finally, real-time monitoring is carried out on the operation of the transmission line, and an alarm is carried out according to the relative importance of the trip. The practical application performance of the new monitoring platform is verified by comparative experiments. The experimental test shows that the proposed platform can ensure the correctness of monitoring and has faster monitoring response efficiency.
Building a Unified Spatio-Temporal Data Model for Grid Resources Based on Microservice Architecture
Authors: Dai Haoqi , Chen Yuxu , Ren Haowen , Li Xiaolu , Ao Zhiqi
Published: December 2022

Under the background of accelerating the process of power grid construction, the unified spatial-temporal data model of power grid resources has become a necessary means to describe the relationship between spatial objects and power grid data. Affected by the defect of the information island, some unified spatiotemporal data models of power grid resources have poor updating performance. Therefore, a unified spatiotemporal data model of power grid resources based on microservice architecture is designed. The architecture can obtain the spatial structure elements of the power grid area, identify the spatial correlation characteristics of the modeling object through the distribution of power energy supply lines, eliminate the dimension of meteorological data variables, design a unified resource scheduling scheme based on the microservice architecture, calculate the space-time weight matrix, and build a space-time data model. Test results are that under the two update task scenarios, the average update performance of the unified spatiotemporal data model of power grid resources based on the Internet of things is 11363 times/second. The average update performance of the unified spatiotemporal data model of power grid resources based on the Internet of things is 9958 times/second). And the average update performance of the unified spatiotemporal data model of power grid resources based on the genetic algorithm is 9771 times/second. It shows that the designed unified spatiotemporal data model of power grid resources is perfect after combining the microservice architecture.
A Distributed Adaptive Control Model for Microgrids with a Microservice-oriented Architecture
Authors: Cao Xiaoming , Zhang Huabing , Shi Hongyu
Published: December 2022

In the face of increasingly complex application conditions, some distributed adaptive control models for microgrids suffer from large differences between voltage magnitudes and rated values. To address such shortcomings, a distributed adaptive control model for microgrids is designed for a microservice architecture. The mathematical expressions of the state integral control variables and control input variables under steady-state conditions are derived by extracting the integral control variables of the distributed generation units of the microgrid, and the current at the end of the line short circuit is used as the database to design the current quick-break protection mechanism for the microservice architecture. Experimental results is that the voltage magnitude of the distributed adaptive control model of the microgrid in the paper is 317.71V, which is closer to the rated output voltage value of 320V, indicating that the distributed adaptive control model of the microgrid is better when the microservice architecture is fully utilized.
Transformer Connection Terminal Registration Based on Objective Function
Authors: Dai Jianzhuo , Zhang Sicong , Tao Jiagui , Hu Kaifeng
Published: December 2022

In recent years, the traditional ICP algorithm has high requirements for the initial position of point clouds, and low registration ability for point clouds with low overlap. The Microsoft Kinect depth sensor was used to obtain the point cloud data of the target object from the real scene. Then, pre-processing such as point cloud segmentation, filtering and down sampling. In the coarse registration, the feature point sampling consistency algorithm was used to make the point cloud obtain a better initial position. Finally, a point-to-surface ICP algorithm optimized by linear least squares was proposed in the fine registration. The experimental results show that the root mean square error of the improved algorithm is 0.761mm and the time is 52.32ms. Compared with the ICP algorithm based on SIFT feature points and the improved ICP algorithm based on feature point sampling consistency, the registration accuracy of the improved algorithm is increased by 21.0% and 43.3%, and the speed is increased by 18.9% and 30.2%.
Research on Efficient Detection Method of Foreign Objects on Transmission Lines Based on Improved YOLOv4 Network
Authors: Shan Hua , Song Yu , Wang Hongxing , Chen Yuquan
Published: December 2022

The normal operation of transmission lines is one of the basic guarantees for industrial development. The foreign object on the transmission line is one of the main reasons for the failure of the transmission line, which brings huge economic losses to the society. The traditional method has the problem of low accuracy and slow speed. The detection and identification of foreign objects on transmission lines are beneficial to the maintenance of huge economic benefits. Therefore, cloud-edge technology is introduced into this study, and a monitoring model for foreign objects on transmission lines in complex scenarios based on an improved YOLOv4 network is proposed. The feature extraction module of the YOLOv4 model is improved based on the GhostNet network to speed up the detection of foreign objects. The SPP module in the YOLOv4 network is improved to enhance the accuracy of detection and identification of foreign objects on transmission lines. The accuracy and speed of the detection of foreign objects tested are 99.2% and 218ms, respectively. The experimental results can meet the needs of real-time detection.
A new approach for calculating the average frequency of power system based on the identification of regional inertia center nodes
Authors: Wan Zhonghui , Liu Fusuo , Wu Xuelian
Published: December 2022

The grid structure of the modern power system is complex and the space span is large. When the power system is disturbed to generate unbalanced power, the transient distribution process among the various synchronous units leads to the spatiotemporal distribution characteristics of the frequency response of the system. By measuring the generator Frequency and Inertia, the inertia center frequency can be calculated. Based on the two-generator system, the relationship between generator frequency and bus frequency is analyzed. A method for selecting the frequency inertia center node of the local power grid in the power system is proposed, and the inertia center frequency of the system is estimated based on the measured frequency at this point. Taking 10 machines and 39 nodes as an example, the simulation calculation is carried out to verify the effectiveness of the proposed method.
Cogging Torque Reduction of Permanent Magnet Motor Based on Particle Swarm Optimization Algorithm
Authors: Zhang Linsen , Tang Bo , Tan Siwei , Ning Xiaoling
Published: December 2022

The permanent magnet motor will inevitably produce cogging torque because of its inherent structure, which will cause vibration and noise and affect its application in certain high-precision applications. Firstly, considering the actual cogging structure of the stator, a general analytical model of cogging torque of the permanent magnet motor is obtained by the energy-based approaches. On the basis of the further derivation of cogging torque analytical expressions with different segmented pole structures, a cogging torque combination reduction method is presented based on the particle swarm optimization algorithm, by comprehensively optimizing three different combinations of the opening width of stator slot, the calculating pole arc coefficient and the number of PM pole segments, the method can reduce the “peak-to-peak value” of cogging torque. The finite element analysis (FEA) results prove the validity of the proposed method.
An Improved Dynamic Smooth Weighted Round-robin Load-balancing Algorithm
Authors: Gao Chenhao , Wu Hengyang
Published: December 2022

Load-balancing is a key component of highly available network infrastructure. Weighted round-robin is one of the important strategies to achieve load-balancing, which is a classic research subject. In recent years, the weighted round-robin algorithm has developed from static weight to dynamic. The Dynamic weighted round-robin algorithm needs further research in time-sensitive of dynamic weights and the rationality of results. Based on Nginx, this paper improves the dynamic weighting algorithm. Firstly, it proposes a method of dynamically calculating weights. The method determines the weight of the server in the cluster according to its theoretical performance and runtime state. Secondly, making the request allocation result more balanced and avoiding continuous centralized scheduling by an improved weighted algorithm. Experiments show that the algorithm proposed in this paper is effective and can improve system performance and load-balancing efficiency.
Large-Scale Power Cloud Resource Scheduling Algorithm in an Edge Computing Environment
Authors: Huang Xiang , Liang Zhihong , Zhang Qiankun , Mo Jianfeng , Zhao Lei
Published: December 2022

Aiming at the problem that the current power cloud resource scheduling is inefficient and time-consuming, a large-scale power cloud resource scheduling algorithm in an edge computing environment is proposed. Firstly, the resource management method of large-scale power clouds is optimized. Considering the resource sharing and task scheduling security requirements between secondary nodes, and combined with edge computing technology, the resource distribution management and scheduling algorithm of the power cloud are optimized. Finally, the experiment proves that the resource scheduling time of a large-scale power cloud resource scheduling algorithm under an edge computing environment is reduced by more than 15 minutes in the actual application process, And the scheduling effect is also better than the traditional method.
Researches Advanced in Human Pose Estimation Based on Deep Learning
Authors: Song Xuzhe
Published: December 2022

Human pose estimation has always been a popular research topic in the discipline of computer vision, which aims to predict the spatial position of the human body’s key points (parts/joints) from a given image or video. Benefiting from the powerful feature representation ability of the convolutional neural networks, the pose estimation methods based on the deep learning have become the mainstream framework of this task, which obtain the human pose estimation results by extracting the human pose feature information at different scales with specific neural networks and using the corresponding methods to process it. This paper, based on the depth study of human body posture estimation can be divided into single-task and multi-person missions. The time and method of correlation are classified and summarized, respectively from the network architecture, algorithm and feature extraction of performance that are analyzed. The current problems existing in the research field and methods are summarized, and the research prospect for the future has been prospected.
Image Super-Resolution via Multi-scale Channel Attention Residual Network
Authors: Yang Caidong , Sun Fangwei , Li Chengyang , Zhou Heng , Du Ziwei , Li Zhongbo , Xie Yongqiang
Published: December 2022

The refinement of existing CNN-based Super-resolution Reconstruction (SR) networks mainly focuses on deeper network architecture, which hinders the transmission of information in the networks. A deeper network is unable to make full use of intermediate correlation features and makes the training of the network difficult. To solve these problems, we propose a multi-scale channel attention residual network (MCAR). Specifically, we propose a multi-scale channel attention fusion module (MCAF) to learn local and global channels feature and capture the long-range dependencies. Furthermore, the multi-scale block is adopted to get the different scale feature representations. The experimental results on four benchmark datasets demonstrate that our models can effectively improve the visual effect of images, and outperform most of the advanced SISR methods in PSNR and SSIM.
Expansion Dynamic and Characterization of Stagnation Layer in Laterally Colliding Plasmas: Dependence of Observation Bandwidth and Plasma Plume Separation
Authors: Al-Juboori Haider M. , McCormack Tom
Published: December 2022

The colliding laser-produced plasma (CLPP) has a wide range of applications in various contexts, that might start with astrophysical applications or pulsed laser deposition or Laser-Induced Breakdown Spectroscopy (LIBS), which is a powerful analytical technique for elemental analysis and material identification.

In CLPP experiments, the stagnation layer might form at the interface region when two dense laser-induced plasmas collide, and the degree of stagnation can be diagnosed by the collisionality parameter that is used to determine what kind of interaction will take place, i.e., soft or hard stagnation.

Our experimental work presents the results of the temporal, spatial and semi-spectrally imaging of colliding plasmas of aluminium and silicon targets. The analysis is focused on describing the velocity of the expanding plasma front for the interaction zone. The aim of the work presented here is to further advance and study colliding plasma techniques, as well as other methods to realize and control species density and expansion, with a view to a deep understanding of these complex mechanisms and optimising emission in the visible wavelength range.

All investigation sequences were based on a similar experimental setup, where two different focusing lenses were used with an effective focal length (EFL) of approx. 100mm or 125mm to achieve seed separation around 1.66mm or 2.16mm, respectively. Time-resolved emission imaging was employed to track the stagnation layer‛s size and shape, which might act as a signature of hard versus soft stagnation.

The study provides a considerable amount of detailed data related to the expansion velocity of the interaction zone which extends the understanding of the behaviour of particular species within colliding laser-produced plasmas.
Meibomian gland loss area and its relationship with eyelid margin hyperemia and meibomian gland orifice plugging
Authors: Garcia-Queiruga Jacobo , Sabucedo-Villamarin Belén , Pena-Verdeal Hugo , Garcia-Resua Carlos , Giraldez M. Jesus , Yebra-Pimentel Eva
Published: December 2022

Purpose: The aim of the present study was to state a relationship between the meibomian gland loss area (MGLA), eyelid hyperemia and meibomian gland (MG) orifices plugging in a sample of university students. Material and methods: A total of 74 participants were recruited. Meibography images were obtained with the OCULUS® Keratograph 5M and MGLA was calculated using the ImageJ software; also, MGLA was categorized following the Meiboscale into 4 groups: group 1 (<25%), group 2 (25-50%), groups 3 (50-75%), and group 4 (>75%). An exhaustive slit lamp examination of both eyelids was performed. Eyelid margin hyperemia and MG orifices plugging of each eyelid were categorized following Arita et. al grading scales. Results: A significant statistical relationship was found between MG orifices plugging and MGLA for both eyelids (Fisher’s exact test; both p < 0.019). Also, correlations were obtained between lower MGLA and lower MG orifices plugging (Cramer-V = 0.583, p ≤ 0.001); and between upper MGLA and upper eyelid margin hyperemia (Cramer-V = 0.418, p = 0.023), and upper MG orifices plugging (Cramer-V = 0.413, Fisher’s exact test: p = 0.042). Conclusion: MGLA varies depending on MG orifices plugging in upper and lower eyelids; also, in upper eyelids MGLA was correlated with eyelid hyperemia.