bluuebunny/crossref_metadata_2025 huggingface dataset:
A Unified Strategy for Formal Derivation and Proof of Binary Tree Nonrecursive Algorithms
Authors: ZUO Zhengkang , HUANG Zhipeng , FANG Yue , HUANG Qing , WANG Yuan , WANG Changjing
Published: November 2022

In the formal derivation and proof of binary tree algorithms, Dijkstra's weakest predicate method is commonly used. However, the method has some drawbacks, including a time-consuming derivation process, complicated loop invariants, and the inability to generate executable programs from the specification. This paper proposes a unified strategy for the formal derivation and proof of binary tree non-recursive algorithms to address these issues. First, binary tree problem solving sequences are decomposed into two types of recursive relations based on queue and stack, and two corresponding loop invariant templates are constructed. Second, high-reliability Apla (abstract programming language) programs are derived using recursive relations and loop invariants. Finally, Apla programs are converted automatically into C++ executable programs. Two types of problems with binary tree queue and stack recursive relations are used as examples, and their formal derivation and proof are performed to validate the proposed strategy's effectiveness. This strategy improves the efficiency and correctness of binary tree algorithm derivation.
The Nobel Prize time gap
Authors: Mitsis Pandelis
Published: November 2022

The time lag between the publication of a major scientific discovery and the conferment of a Nobel Prize has been rapidly increasing for the natural science disciplines (chemistry, medicine-physiology, and physics), but has not yet matched the corresponding “waiting period” for the Nobel Prize in Economics. The aim of the present study is to empirically examine the time gap between pioneering work and Nobel recognition and discuss possible explanations for its variation across time and disciplines. The analysis provides evidence to support the argument that attributes such as bestowments of accolades widely regarded as Nobel Prize precursors, citation indices, and sharing of the award between multiple recipients, may explain this variation, but only to some extent. In the discussion that follows, the notably longer waiting period in economics is attributed to factors such as the laureates’ age, the impact of which the current study cannot empirically examine. Since the Nobel Prize cannot be awarded posthumously, the Nobel Committee members may tend to grand the award to older economists before they pass away and become ineligible.
Magnetic hopfions in solids
Authors: Rybakov Filipp N. , Kiselev Nikolai S. , Borisov Aleksandr B. , Döring Lukas , Melcher Christof , Blügel Stefan
Published: November 2022

Hopfions are an intriguing class of string-like solitons, named according to a classical topological concept classifying three-dimensional direction fields. The search for hopfions in real physical systems has been ongoing for nearly half a century, starting with the seminal work of Faddeev. However, so far, realizations in bulk solids are missing. Here, we show that hopfions appear as emergent particles of the classical Heisenberg model with competing exchange interactions. This requires going beyond the model approach used in prior work and deriving a general micromagnetic energy functional directly from a spin-lattice Hamiltonian. We present a definite parameter space in which the existence of hopfions is possible. This opens a concrete vista to combine computational approaches such as density functional theory with material informatics to find magnetic crystals that can host hopfions. As proof of principle, we show how zero-field hopfions can be visualized by the means of off-axis electron holography in a transmission electron microscope.
Measurements of emissivity and temperature for polarized long-wavelength infrared light from tungsten under simulating tokamak conditions
Authors: Shu Shuangbao , Wu Tianqi , Yang Ziqiang , Yang Jianhua , Zhang Yuzhong , Wang Ziyi , Liang Huajun
Published: November 2022

Tungsten is regarded as the baseline first wall material in tokamaks. This work provides a polarized method for measuring the emissivity and temperature of the tungsten using an infrared camera and a polarizer under simulating tokamak conditions. In the experiment, a polarizer with an adjustable polarization direction is set up in front of an infrared camera. A rotatable fixture is used to fix the sample and change the angle between the surface and the normal. The sample is rotated from 0° to 80°, and the polarized emissivity first increases and then decreases with increasing rotation angle. The uncertainty in emissivity resulting from this polarized method and non-polarized method is analyzed. To compare the effects of the polarized method and the non-polarized method, the rotation angle is adjusted to 0°, and a fitting model is used to describe the relationship between emissivity and temperature. Errors between the calculated temperature and measured temperature are used as a scale, and the polarized method improves the accuracy of temperature measurement. This polarized method provides a technical way to measure the emissivity and temperature in a tokamak and can be applied in other similar applications.
Metropolitan single-photon distribution at 1550 nm for random number generation
Authors: Gyger Samuel , Zeuner Katharina D. , Lettner Thomas , Bensoussan Sandra , Carlnäs Martin , Ekemar Liselott , Schweickert Lucas , Hedlund Carl Reuterskiöld , Hammar Mattias , Nilsson Tigge , Almlöf Jonas , Steinhauer Stephan , Llosera Gemma Vall , Zwiller Val
Published: November 2022

Quantum communication networks will connect future generations of quantum processors, enable metrological applications, and provide security through quantum key distribution. We present a testbed that is part of the municipal fiber network in the greater Stockholm metropolitan area for quantum resource distribution through a 20 km long fiber based on semiconductor quantum dots emitting in the telecom C-band. We utilize the service to generate random numbers passing the NIST test suite SP800-22 at a subscriber 8 km outside of the city with a bit rate of 23.4 kbit/s.
Characterization of commercial thermoelectric modules for precision heat flux measurement
Authors: Crossley Jacob , Elahi A. N. M. Taufiq , Ghashami Mohammad , Park Keunhan
Published: November 2022

In this article, we present a cost-effective approach to the precision measurement of heat flux using commercial thermoelectric modules (TEMs). Two different methods of measuring heat flux with TEMs are investigated, namely, passive mode based on the Seebeck effect and active mode based on the Peltier effect. For both modes, a TEM as a heat flux meter is calibrated to show a linear relation between the voltage across the TEM and the heat flux from 0 to ∼450 W m−2. While both modes exhibit sufficiently high sensitivities suitable for low heat flux measurement, active mode is shown to be ∼7 times more sensitive than passive mode. From the speculation on the origin of the measurement uncertainty, we propose a dual TEM scheme by operating the top TEM in passive mode while its bottom temperature maintains constant by the feedback-controlled bottom TEM. The dual TEM scheme can suppress the sensitivity uncertainty up to 3 times when compared to the single-TEM passive mode by stabilizing the bottom temperature. The response time of a 15 × 15 mm2 TEM is measured to be 8.9 ± 1.0 s for heating and 10.8 ± 0.7 s for cooling, which is slower than commercial heat flux meters but still fast enough to measure heat flux with a time resolution on the order of 10 s. We believe that the obtained results can facilitate the use of a commercial TEM for heat flux measurement in various thermal experiments.
Assessing the quality of QM/MM approaches to describe vacuo-to-water solvatochromic shifts
Authors: Nicoli Luca , Giovannini Tommaso , Cappelli Chiara
Published: November 2022

The performance of different quantum mechanics/molecular mechanics embedding models to compute vacuo-to-water solvatochromic shifts is investigated. In particular, both nonpolarizable and polarizable approaches are analyzed and computed results are compared to reference experimental data. We show that none of the approaches outperform the others and that errors strongly depend on the nature of the molecular transition to be described. Thus, we prove that the best choice of embedding model highly depends on the molecular system and that the use of a specific approach as a black box can lead to significant errors and, sometimes, totally wrong predictions.
Absolute response of a proton detector composed of a microchannel plate assembly and a charge-coupled device to laser-accelerated multi-MeV protons
Authors: Mahmood M. Ahsan , Ahn Gwang-Eun , Lee Sang Hwa , Kim Seung Yeon , Ahmad Izhar , Tahir Sajjad , Yang Jeong Moon , Yoon Jin Woo , Sung Jae Hee , Lee Seong Ku , Choi Il Woo , Nam Chang Hee
Published: November 2022

The absolute response of a real-time proton detector, composed of a microchannel plate (MCP) assembly, an imaging lens, and a charge-coupled device (CCD) camera, is calibrated for the spectral characterization of laser-accelerated protons, using a Thomson parabola spectrometer (TPS). A slotted CR-39 plate was used as an absolute particle-counting detector in the TPS, simultaneously with the MCP–CCD detector to obtain a calibration factor (count/proton). In order to obtain the calibration factor as a function of proton energy for a wide range of proton numbers, the absolute response was investigated for different operation parameters of the MCP–CCD detector, such as MCP voltage, phosphor voltage, and CCD gain. A theoretical calculation for the net response of the MCP was in good agreement with the calibrated response of the MCP–CCD detector, and allows us to extend the response to higher proton energies. The response varies in two orders of magnitude, showing an exponential increase with the MCP voltage and almost linear increase with the phosphor voltage and the CCD gain. The calibrated detector enabled characterization of a proton energy spectrum in a wide dynamic range of proton numbers. Moreover, two MCP assemblies having different structures of MCP, phosphor screen, and optical output window have been calibrated, and the difference in the absolute response was highlighted. The highly-sensitive detector operated with maximum values of the parameters enables measuring a single proton particle and evaluating an absolute spectrum at high proton energies in a single laser shot. The absolute calibrations can be applied for the spectral measurement of protons using different operating voltages and gains for optimized response in a large range of proton energy and number.
Cavitation induced oil-in-water emulsification pathways using a single laser-induced bubble
Authors: Raman K. Ashoke , Rosselló Juan Manuel , Ohl Claus-Dieter
Published: November 2022

The interaction between a single laser-induced cavitation bubble and a microsized water droplet is investigated experimentally. This interaction results in the fragmentation of the droplet as the bubble undergoes multiple cycles of expansion and collapse inside the droplet. In particular, we report three distinct pathways for the formation of oil-in-water (O/W) emulsions: crown jetting, oil finger rupture, and induced jetting. The formation of these internal O/W emulsions is usually a combination of either two or all three identified pathways. These observations offer insight into the formation process of cavitation-induced microemulsions.
Child rearing and parenting programs among First Nations’ populations in high-income countries: a bibliometric review
Authors: Waller Amy , Ampofo Ama , Bryant Jamie , Sanson-Fisher Robert W.
Published: November 2022

Objectives We set out to examine the volume, scope and quality of research related to First Nations peoples’ perceptions of, and experiences with, child rearing and/or parenting programs. Methods We systematically reviewed the literature published between 2000 and 2020. Sixty-eight studies identified through electronic databases and references lists met inclusion criteria. Results The study found an 8% increase in publications in the field each year (P-value = 0.002), mostly conducted in Australia with Aboriginal and Torres Strait Islander people (n = 29, 41%). Scope included positive and negative experiences relating to: parenting from adult (n = 19 studies) and teenager (n = 4) perspectives; and pregnancy, antenatal and postnatal care from the perspective of adults (n = 23) and teenagers (n = 2). Descriptive studies included qualitative (n = 40; 58%), quantitative (n = 8, 12%) or mixed methods (n = 7, 10%). Thirteen experimental studies reported the development, acceptability and/or effectiveness of programs (19%), of which three met the Cochrane Effective Practice and Organisation of Care design criteria. Conclusions Despite an overall increase in volume, research efforts do not demonstrate a clear scientific progression. Further methodologically rigorous studies examining child rearing and/or parenting programs developed in collaboration with First Nations populations are needed.
Convergence of the Fefferman-Graham expansion and complex black hole anatomy
Authors: Serantes Alexandre , Withers Benjamin
Published: November 2022

Given a set of sources and one-point function data for a Lorentzian holographic QFT, does the Fefferman-Graham expansion converge? If it does, what sets the radius of convergence, and how much of the interior of the spacetime can be reconstructed using this expansion? As a step towards answering these questions we consider real analytic conformal field theory data, where in the absence of logarithms, the radius is set by singularities of the complex metric reached by analytically continuing the Fefferman-Graham radial coordinate. With the conformal boundary at the origin of the complex radial plane, real Lorentzian submanifolds appear as piecewise paths built from radial rays and arcs of circles centred on the origin. This allows singularities of Fefferman-Graham metric functions to be identified with gauge-invariant singularities of maximally extended black hole spacetimes, thereby clarifying the physical cause of the limited radius of convergence in such cases. We find black holes with spacelike singularities can give a radius of convergence equal to the horizon radius, however for black holes with timelike singularities the radius is smaller. We prove that a finite radius of convergence does not necessarily follow from the existence of an event horizon, a spacetime singularity, nor from caustics of the Fefferman-Graham gauge, by providing explicit examples of spacetimes with an infinite radius of convergence which contain such features.
Development of a ReaxFF potential for Au–Pd
Authors: Rusalev Yu V , Motseyko A V , Guda A A , Guda S A , Soldatov A V , Ter-Oganessian N V
Published: November 2022

The bimetallic alloys often outperform their single-component counterparts due to synergistic effects. Being widely known, the Au–Pd alloy is a promising candidate for the novel heterogeneous nanocatalysts. Rational design of such systems requires theoretical simulations under ambient conditions. Ab initio quantum-mechanical calculations employ the density functional theory (DFT) and are limited to the systems with few tens of atoms and short timescales. The alternative solution implies development of reliable atomistic potentials. Among different approaches ReaxFF combines chemical accuracy and low computational costs. However, the development of a new potential is a problem without unique solution and thus requires accurate validation criteria. In this work we construct ReaxFF potential for the Au–Pd system based on ab initio DFT calculations for bulk structures, slabs and nanoparticles with different stoichiometry. The validation was performed with molecular dynamics and Monte-Carlo calculations. We present several optimal parametrizations that describe experimental bulk mechanical and thermal properties, atomic order-disorder phase transition temperatures and the resulting ordered crystal structures.
Mechanistic investigation of formation of highly-dispersed silver nanoparticles using sea buckthorn extract
Authors: Kaur Hardeep , Anand Vivek , Sharma Ajay , Verma Meenakshi , Sareen Shweta , Mehta Surinder Kumar , Mutreja Vishal
Published: November 2022

Nowadays, the greener pathways for the synthesis of nanostructures are being explored. The extracts of different parts of plantsvizleaves, stems, and roots have been investigated. However, these extracts have been prepared by simply boiling or microwaving, or sonicating the parts of plants with water. Therefore, to have deeper insight and to investigate the full potential of plant extracts, serial extraction of leaves of sea buckthorn (Hippophae rhamnoides L.) which is a medicinally important plant was attempted using the soxhlet apparatus. The as-obtained polyphenolic-rich extract was employed for the preparation of silver nanoparticles (Ag−NPs). Under optimized reaction conditionsviz60 °C temperature and 500μl of extract solution (5 mg ml−1) highly disperse spherical nanoparticles of the average size of 15.8 ± 4.8 nm were obtained. Further, the optical band gap of Ag−NPs prepared using optimized reaction conditions was found to be 2.6 eV using the Tauc equation. Additionally, to understand the reduction by the extract, kinetic studies were also carried out which suggest the predominant occurrence of pseudo-first-order reaction. Furthermore, the mechanism of formation of Ag−NPs using major components of extractvizgallic acid and catechin which were identified by HPLC were also investigated using DFT. The mechanistic investigation was performed for both the keto-enol and radical-mediated preparation of Ag−NPs. Such theoretical investigations will help in the efficient designing of greener and novel routes for the synthesis of Ag−NPs. Additionally, the prepared silver was also employed for the colorimetric detection of H2O2.
Amalgamation of rare-earth neodymium ions with ZnO nanoparticles: extensive investigations into the microstructure and optical properties
Authors: Senthil Kumari S , Nirmala W , Chidhambaram N , Prabu M , Gobalakrishnan S , Thirumurugan Arun
Published: November 2022

A comprehensive study is envisioned to examine the influence of rare-earth (RE) metal doping on the zinc oxide (ZnO) matrix. A wet-chemical methodology is adopted to synthesize pristine and neodymium (Nd)-doped ZnO nanoparticles (NPs). Crystal structure analysis substantiates that RE doping does not form any secondary phases related to RE metal clusters or oxides. The average crystallite and apparent strain values of the synthesized NPs are obtained from the size-strain plot approach. In addition to the typical absorption edge of ZnO, the characteristic absorption bands of Nd3+ ions are also detected in the doped ZnO NPs. Light-emission studies reveal photoluminescence quenching for up to 3 wt.% of Nd-doping, and 5% doping causes an enhanced ultraviolet emission in the Nd-doped ZnO matrix. Additional functional groups that co-exist with the NPs are identified using Fourier transform infrared spectroscopy. Energy dispersive x-ray studies corroborate the existence of constituent elements in the doped ZnO matrix.
Dependence of dynamic resistances in high-temperature semiconducting quasi-isotropic strands on magnitude and orientation of AC magnetic field
Authors: Wang Yinshun , Wang Jian , Liu Wei , Wang Jiawen , Meng Ziqing , Pi Wei
Published: November 2022

The dynamic resistance of a superconductor appears if it carries a direct current (DC) current and is simultaneously exposed to alternative current (AC) magnetic fields if its amplitude is higher than its full penetrated field. Due to its strong anisotropy, the dynamic resistance of high-temperature superconducting (HTS) tape is not only affected by the magnitude of AC magnetic fields but also their orientations. In particular, the dynamic resistance has considerable effect on the current distribution in HTS cables (except for Roebel cables) and even cable-in-conduit conductors made from those HTS cables, except for dissipative loss. This paper presents the behavior of dynamic resistance in an HTS quasi-isotropic strand (Q-IS), which consists of four sub-stacked 2G HTS tapes proposed by our group at North China Electric Power University, while it carries a DC current and simultaneously experiences an AC magnetic field with different magnitudes and orientations. An angular dependence of dynamic resistance in a single 2G HTS tape in an AC magnetic field with various orientations is first performed in simulations and experiments, respectively. The experimental results are in good agreement with the simulated ones, which shows that the dynamic resistance of a Q-IS also exhibits quasi-isotropic characteristics and has an important effect on the distribution of DC transport current. The related results are promising for the design and application of other DC HTS cables, feeders and magnets.
Quasi-one-dimensional characters in topological semimetal TaNiTe5
Authors: Ma Ni , Wang De-Yang , Huang Ben-Rui , Li Kai-Yi , Song Jing-Peng , Liu Jian-Zhong , Mei Hong-Ping , Ye Mao , Li Ang
Published: November 2022

One-dimensional (1D) topological insulators are superior for low-dissipation applications owing to the 1D character of surface states where scatterings other than prohibited backscattering are further restricted. Among the proposed candidates for 1D topological materials, TaNiTe5 has attracted intensive attention for its quasi-one-dimensional (quasi-1D) crystalline structure. In this study, we identify the chain-like construction and anisotropic electronic states on TaNiTe5 surface with scanning tunneling microscopy. The electron scatterings are largely suppressed even with chromium impurities deposited on the surface and magnetic field applied normal to the surface, which endows TaNiTe5 great potential for low-dissipation spintronic applications.
Inverse kinematics solution of CMOR short carrier manipulator
Authors: Zhang Heng , Dong Xiang , Fang Ning , Zhang Jun , Cheng Yong
Published: November 2022

CMOR is a heavy-duty manipulator system applied to the maintenance of fusion reactor components. On the basis of fully considering the configuration characteristics of the manipulator, the geometric solution based on coordinate transformation combined with the analytical method is used to solve the inverse kinematics of the manipulator. First, the modified D-H method is used to establish the link coordinate system model of the CMOR carrier manipulator, and the forward kinematics is deduced. Then, based on the end pose 0T7 and the geometric structure of the manipulator, the movement range of the redundant degree of freedom d1 is deduced, and the remaining joint angles are obtained through the mapping solution and verified in MATLAB. The simulation results show that the method has high precision, reduces the overall calculation amount, and is conducive to the real-time and accurate maintenance movement of the carrier manipulator, which is of great significance for the maintenance of fusion reactors.
Motion analysis of armored vehicle suspension based on ADAMS
Authors: Yuan Xinjian
Published: November 2022

This paper takes the suspension of a 8×8 wheeled armored vehicle as the research object, uses Pro-E to model the armored vehicle, uses ADAMS simulation software to simulate the kinematics of the established suspension model, and analyzes the motion characteristics of the armored vehicle suspension from three aspects: positioning parameters, track width and suspension stiffness. It provides a reference for the optimal design of operational stability and ride comfort of wheeled armored vehicles.
Design of actuator of marine garbage cleaning vessel based on ocean wave driving
Authors: Zou JiangMeng , Zhu Xi , Han Zhi , Li Chun
Published: November 2022

There are usually two ways to salvage and clean the garbage floating in the ocean, one is relying on manual and the other one is dependent on garbage salvage vessel driven by fuel oil. It is known that human collection is time-consuming and laborious, and machinery driven by fuel produces pollutant and pollutes the ocean environment in return. Taking these issues into consideration, this study designed a marine garbage cleaning vessel based on ocean wave driving which could gather and collect the floating garbage on the sea. The structure of the vessel actuator mainly constructed of a buoy-ratchet mechanism, the gear set-differential mechanism, the incomplete teeth-gathering mechanism, and a conveyor belt for transporting garbage. Through innovative structural design, this device could drive the whole transmission system by wave energy, which not only improves the work efficiency, increases reliability of structures but also reduces the consumption of manpower and material resources. Thus, the mechanical vessel is in line with sustainable development strategy, making full use of natural resources to clean ocean waste, and has a very high practical application value.
A New Derailment Detection Method of Rail Vehicles
Authors: Tao Qiang , Sun Xiaojie , Liu Yi , Dai Chenxi , Zhao Yulun
Published: November 2022

Aiming at the problem of train derailment detection, researchers at domestic and abroad mainly focus on the derailment coefficient and wheel load reduction rate, but the derailment coefficient and wheel load reduction rate can’t accurately reflect the status of rail vehicle derailment in time. In this paper, a new derailment detection method of rail vehicles is designed based on the lateral acceleration and roll angle as the key characteristic physical quantities of wheelset derailment. Firstly, the virtual simulation method is used to grasp the characteristics of the key physical quantities. Then, the appropriate scheme of derailment detection system is proposed to measure the key characteristic physical quantities and judge whether the rail vehicle is derailed. Finally, the simulation data is used to prove the effectiveness of the detection method, which can lay the foundation for the practical engineering application.
Design and Verification of Simulation Data Generator for Rail Transit Switch Machine
Authors: Wei Shiyan , Zou Jinbai , Sha Quan , Ji Guoyi
Published: November 2022

Because the fault data of rail transit switch machine are difficult to obtain and the site fault is difficult to reproduce, it is difficult to diagnose or predict the switch machine. In this paper, the power fault data of S700K switch machine is divided into creeping fault and mutation fault, and a simulation data generator for generating massive fault data is developed. The generators involve the synthesis of minority over-sampling techniques and generative confrontation networks. Finally, the long-term memory neural network is used to predict the generated gradual fault data to verify the authenticity and reliability of the simulation data generator. The experimental results show that the generated data can predict the future power trend of the switch machine, which proves the authenticity and feasibility of the simulation data generator.
Development of an Adaptive Wall-pressing Mechanism for an In-pipe Cleaning Robot
Authors: Yang Zeyu , Fan Yuanxun , Yan Yu
Published: November 2022

This paper proposes a novel adaptive wall-pressing mechanism for an in-pipe cleaning robot (ICR) which combines two type of self-adaptive mechanisms. Parametric modelling and optimization for the mechanism is proceeded in order to improve the carrying capacity and adaptability of the robot in the water supply pipeline. Force in the compression spring due to the self-weight of ICR is reduced by 31% after optimization. A virtual simulation platform is established to analyse the stability and obstacle-surmounting capacity of ICR under different pre-loading forces.
Numerical simulation analysis of the flow field in the bore of a two-stage light gas gun
Authors: Dong Jinlin , Cao Bing
Published: November 2022

In order to study the effect of different launch tube diameters of gas-driven two-stage light gas guns on the flow field during the launch process, a model of the piston movement in the pump tube to the projectile launch was established using Fluent. Using the dynamic mesh technology and 6DOF model, a numerical simulation of the projectile launch process of the two-stage light gas gun was carried out, and the effects of different launch tubes on the projectile velocity and the flow field in the bore were obtained. The results show that when the mass difference between the piston and the projectile is large, appropriately increasing the diameter of the launch tube is conducive to the flow of gas in the high-pressure cone and increases the projectile launching speed. The numerical simulation analysis of the flow field in the bore provides a basis for the design and optimization of the two-stage light gas gun.
Particle image recognition in the measurement of workpiece cleanliness
Authors: Long Zhiqiang , Wang Jiangang , He Fengqin , Sun Mochuan , Lian Fengqi , Zhong Jiancheng , Shangguan Qianqian , Zhang Qiuhong
Published: November 2022

Monitoring the cleaning degree of workpiece surface cleaning is a key step in high-end equipment manufacturing. The use of image recognition technology to identify the cleaning degree of workpiece surface can effectively improve the quality and efficiency of workpiece cleaning. In this paper, a particle image recognition technology based on opencv was proposed, which uses a series of methods such as grayscale, binarization, morphological processing, line contour detection, contour extraction to statistically calculate the number and average size of particles. So that the surface cleanliness of the workpiece can be determined. Judging the surface cleanliness classification according to the particle size and quantity is a precise quantitative cleaning method.
Research on synchronization of cooperative trajectory of dual industrial robots based on fuzzy adaptive PID control strategy
Authors: Xiong Qiang , Wang Jianqun
Published: November 2022

Through the research on the synchronization of the cooperative trajectory of dual industrial robots, this paper analyses the characteristics of master-slave control and distributed control, and puts forward a fuzzy adaptive PID control method suitable for the cooperative scene of dual industrial robots, which can dynamically adjust the parameters of PID control online and adapt the dynamic system of industrial robots in real time. Taking two same 6-DOF ABB industrial robots as examples, common PID controller and fuzzy PID controller are compared and simulated under master-slave control mode and distributed control mode respectively. The simulation results verified that the fuzzy adaptive PID control method is effective, and the distributed control mode has more applicability and expansibility than the master-slave control mode.
AHSM-Net: Unsupervised Stereo Matching Algorithm Based on Attention Mechanism and Hybrid Dilated Convolution
Authors: Li Xiaoge , Zhao Xingfang , Yan Long
Published: November 2022

Too many parameters often accompany the stereo matching algorithm of the convolutional neural network. The dense matching makes the constructed cost volume increase with the resolution, resulting in high occupied memory and processing time. To perform depth estimation more efficiently, this paper proposes a stereo matching algorithm AHSM-Net based on attention mechanism and hybrid dilated convolution (HDC), which uses an unsupervised method to train the stereo matching network end-to-end. This method obviously enhances the consistency of objects. AHSM-Net is trained on the SceneFlow dataset, and a large number of experiments and analyses are carried out on the KITTI2012 and KITTI2015 datasets, which verifies that the method proposed in this paper has great matching accuracy and speed under the condition of unsupervised.
Structural optimization method of 6-DOF manipulator based on genetic algorithm
Authors: Tu Chenyu , Zhang Long
Published: November 2022

Most of the manipulator is designed under the constraint of motion reversibility, and the optimization of the manipulator structure is often carried out through the study of kinematics. In order to solve the structural optimization problem of a 6-Dof manipulator, this paper proposes a structural optimization method based on a 6-Dof manipulator with comprehensive indexes combining kinematics performance and dynamics performance. On the premise of satisfying the original workspace and taking dynamic performance as evaluation function, genetic algorithm was used to optimize the structural parameters of the manipulator, so that the optimized manipulator not only has the characteristics of the original workspace, but also consumes the least energy. The kinematic equation of the manipulator was derived, the dynamics model was established by Lagrange method, and then the fitness function and the structural optimization algorithm of the manipulator based on genetic algorithm were given.
Event-Triggered Regulation for Enhanced Synchronization of Recurrent Neural Networks using Time-Varying Delay
Authors: Yu Lei , Chen Guici
Published: November 2022

This research is primarily concerned having the synchronization issue of time-varying delay recurrent neural networks (RNNs) with event-triggered regulation (ETR). ETR may legitimately reduce the number of control activities performed and the amount of energy expended. Via the L-K functional, Schur complement lemma, linear matrix inequalities (LMIs), and other analytic techniques, a sufficient condition for the synchronization of the drive-response system is achieved. Consequently, a more sensible and effective controller is implemented. Using a Matlab-made example and graph, we can show that our inferred results are correct and we can ensure the rationality of the set controller.
Design of Lightning Current Monitoring System on Wind Turbines
Authors: Huang Guojian , Huang Jiasi , Li Chunyan , Wu Yuquan , Zhou Junjie , Dai Yating , Li Qingtong
Published: November 2022

In recent years, because climate change is a major issue related to human survival and sustainable development, the global climate is warming and glaciers are melting, so the country has been advocating “green environmental protection, low-carbon life”. To achieve this goal, China is constantly looking for green and sustainable energy. However, in thunderstorm weather, wind turbines are more likely to be attacked by lightning. Even if we have a set of strict technology for lightning protection of wind turbines, we cannot resist direct lightning strikes. The blade of a wind turbine is the first target of lightning strikes. Therefore, this paper designs a lightning current monitoring system for wind turbines based on Rogowski coils, and designs a current measurement system that can be stably used to monitor the whole process of discharge when wind turbines are struck by lightning, so as to improve the safety of wind turbines. To improve the wind power generation technology due to the economic losses caused by lightning strikes to wind power generation enterprises.
Fault injection and diagnosis of the centrifugal fan
Authors: Tang Jing , Guo Guangkuo , Wang Ji , Xu Wei
Published: November 2022

Centrifugal fan is widely used in industry, vehicle and ship application to provide air cycle power. To detect the fan fault at early stage, this paper explores the fault feature in the vibration signal and fault diagnosis method through the fault injection test, where impeller unbalance, rotor unbalance, and bearing fault are involved. Firstly, the fault mechanism is introduced; then, the fault injection methods of the three faults are introduced to obtain the faulty fans; finally, health and fault tests are performed, where the vibration sensors are employed and distributed on the fan in the axial and radial direction. Moreover, the acquired vibration data is analyzed by using time-domain and frequency-domain methods, and further the fault features between health and fault are compared and discussed. The analysis results indicate that the three faults can be detected through the vibration intensity and magnitude comparison at their individual characteristic frequencies in the spectrum.
Health state estimation of lithium ion batteries based on electrochemical impedance spectroscopy
Authors: Zhao Kelun , Ming Zhimao , Wu Jiajie , Sun Wei
Published: November 2022

The estimation method based on the electrochemical impedance spectrum can comprehensively describe the reaction process of Li-ion battery without causing damage to the battery, and is suitable for estimating the state of health of the battery. In this paper, the equivalent circuit model of Li-ion battery is established by analyzing the ac impedance spectrum of Li-ion battery and the internal reaction process of the battery, and corresponding each component of the model and the composite link with the curve segments in the impedance spectrum, and the model parameters are identified offline with the help of The Nyquist diagram of impedance spectrum. It is found that the charge transfer internal resistance and low-frequency impedance amplitude in the equivalent circuit increase monotonically with the aging of the battery. Then, the temperature compensation coefficient was introduced to solve the influence of temperature factors on the SOH estimation of lithium batteries, And the root mean squared error of SOH estimation before and after temperature compensation was reduced from 31.7 to 3.0, and the sum of squares for Error was reduced from 13054.7 to 19.8, which significantly improved the SOH estimation of batteries with different temperatures; and a model based on BP neural network was constructed, And the correlation coefficient of model prediction was 0.994. Solving the influence of production process differences on SOH estimation of lithium batteries, and the advantages and disadvantages of the two estimation methods are summarized.
Research on stress wave wood nondestructive testing technology
Authors: Wei Xiwen , Du Chunxiao , Xu Shuzheng , Tian Cong , Yang Xinnian , Hu Lina , Pang Peng
Published: November 2022

As a kind of nondestructive testing technology, stress wave technology has the advantages of long propagation distance, strong anti-interference ability and convenient use, and has become one of the important means to detect wood properties and defects at home and abroad. This paper introduces several stress wave wood testing equipment commonly used in the field of wood non-destructive testing at this stage, and analyzes its characteristics. The research status of stress wave wood nondestructive testing technology is analyzed from three aspects: mechanical property testing, internal defect testing and factors affecting stress wave propagation velocity. Finally, the existing problems and development trends of stress wave technology in wood nondestructive testing are discussed to provide reference for further research in this field.
The study and development of UAV digital twin system
Authors: Yang Jianfeng , Huang Chuangmian , Wang Jingru
Published: November 2022

To develop the digital twin system of unmanned aircraft vehicle (UAV), a multi-information fusion and time-varying simulation technology based on the testing data is proposed. And a UAV digital twin system is developed. First, the system composition and the working principle of the UAV digital twin system are introduced, respectively. Second, the Ko displacement theory is applied to realize the integration of the acquired data and the finite element simulation model. Then, the model reduced method is introduced, which can reduce the scale of the finite element model and improve the calculation efficiency. Finally, the experimental verification is carried out. The test results and simulation calculation data show that the relative errors between the proposed calculation method and the test results are within 30%, which meets the requirements of engineering application. The test results show that the proposed UAV digital twin technology is feasible, providing a reference case for the development of UAV digital twin technology, which has practical engineering significance and military value.
Anomaly detection based on temporal convolution Autoencoders
Authors: Wu Lihao , Liang Jiahui
Published: November 2022

Due to the rapid growth of the number of sensors in modern industrial society, detecting outliers in time series has become very important. And unsupervised detection of outliers in time series is a very challenging task. For most detection tasks of time series outliers, the autoencoder is one of the main choices. And the recursive network is usually used in the self-coding network structure. However, recent studies have shown that the network structure using dilated causal convolution performs better than the recursive network in all kinds of sequence modeling. In this paper, the encoder and decoder are network structures based on extended causal convolution The time series are reconstructed and then compared with the original data to calculate the distance between them, so as to identify the outliers. We use the Temporal convolution autoencoders to evaluate anomaly data sets in multiple time series. Our results show that the Temporal convolution autoencoders has better anomaly detection ability. In addition, we learned that the combination of Feature Engineering and super parameters will also have a great impact on the results, so ablation experiments need to be carried out carefully.
A High-precision Digital Measurement System Design based on PSR
Authors: Zhou Jianyang , Guan Linhai , Zhang Kai , Zhang Zhihua , Guo Liqiang , Tao Yu
Published: November 2022

In engineering practice, a constant voltage output control system of synchronous rectifier primary side regulator (PSR) flyback converter is proposed to overcome the sampling defect of the existing digital approximation double line sampling scheme for primary side control synchronous rectifier structure. Regardless of the slope of the sampling waveform and the knee point, the single-output DAC midpoint sampling can achieve high sampling accuracy and good knee point following effect. At the same time, the neutral-point sampling error of the single-output DAC is analyzed, and a sampling compensation scheme which can simultaneously act in continuous current mode (CCM) and discontinuous current mode (DCM) is designed to further correct the sampling voltage obtained by neutral-point sampling, so as to compensate the voltage error of neutral-point sampling. Thus, the output voltage can be accurately constant in DCM and CCM.
ADC Clock Jitter Measurement Based on Simple Coherent Sampling Algorithm
Authors: Zhang Shuoyan , Sun Qinghe , Chen Xiaolong , Wang Bocheng , Li Yifan
Published: November 2022

In a high-speed sampling system, the clock jitter of analog-to-digital converters (ADCs) will greatly affect its sampling accuracy, leading to the reduction of the signal-to-noise ratio (SNR) of the system output. Therefore, it is necessary to compensate the sampling results to reduce the sampling error caused by clock jitter by measuring the distribution sequence of jitter. In this paper, the influence of clock jitter on the ADC sampling process is analyzed, and an ADC clock jitter measurement scheme based on a simple coherent sampling algorithm is investigated. This scheme can accurately measure the distribution sequence of clock jitter, and has the characteristics of low computational complexity and high precision. The simulation results show that this algorithm can accurately measure the clock jitter sequence with root-mean-square (RMS) greater than 5ps when the amplitude noise of the input signal is greater than 35dB, and the relative error is less than 5%.
A new type of vertical wall-climbing robot
Authors: Lin Jinfan , Ren Zeming , Hong Xiaobin
Published: November 2022

Using robots to replace human beings to achieve large-scale automatic operations has become an inevitable trend. Wall-climbing robots have important application value in the field of aerial work. For the existing wall-climbing robots have limitation on movement flexibility and overcome own gravity by adsorption friction, this paper innovatively proposes a wall-climbing robot with suspension traction, back push adsorption and McNum wheel driving. Meanwhile, an electronic control system and control algorithm are designed. Experiments results show that the wall-climbing robot has advantages of high relative load, omnidirectional movement, strong continuity of movement and smooth operation.
Tool life prediction based on multi-source feature PSO-SVR neural network
Authors: Wang Ji , Zhou Jian , Mo Wen-An , Liang Chao , Sun Li-Jun , Wen Chun-Bo
Published: November 2022

With the continuous improvement of modern manufacturing automation and process intensification, the complexity of tools and machined parts has greatly increased, and their performance directly affects the quality of workpieces and production efficiency. Accurate prediction of tool life is conducive to improving production efficiency and reducing enterprise costs. In this paper, a tool life prediction method based on multi-source feature PSO-SVR neural network is proposed. By monitoring and collecting the current and vibration signals of the tool during the machining process of CNC machine tools, the time-frequency eigenvalues are extracted. The effective features are extracted by feature selection technology as the input of support vector regression (SVR) neural network, and the parameters of the network are optimized by particle swarm optimization (PSO), so as to improve the accuracy of the predict, and finally predict the remaining useful life(rul) of the tool.
Characteristics of electric double-layer capacitors based on solid polymer electrolyte composed of sodium polyacrylate.
Authors: Tomi Ryu , Daisuke Tashima , Toshihiko Kawabata
Published: November 2022

Despite the low cost and high ionic conductivity of aqueous electrolytes, their practical applications are limited because a low withstand voltage of 1.2 V The energy density increases in proportion to the withstand voltage which is a crucial factor for electric double-layer capacitors (EDLCs) with solid polymer electrolytes. In this study, the electrolyte solution was made into a viscous solid polymer electrolyte to improve the withstand voltage of the electrolyte. The solid polymer electrolyte was prepared from sodium polyacrylate and doped with potassium hydroxide (KOH) and pure water. Sodium polyacrylate can absorb water at the temperature of 16-28 °C and exhibits suitable ion transfer. The EDLCs consisted of a distilled Japanese shochu-waste-activated-carbon electrode, a titanium mesh collector, and a solid polymer electrolyte. All the processes were performed at room temperature. Their electrochemical characteristics were measured using cyclic voltammetry (CV). From CV, the withstand voltage, cycle range, and specific capacitance were evaluated. The performance of the solid polymer electrolyte varied depending on the weight ratio of the constituent sodium polyacrylate and the molar concentrations of the KOH. Here, the value of molar concentration and its variation, depends on the weight ratio of the material. With the addition of sodium polyacrylate, the withstand voltage, which was 1.2 V, rose to over 2 V. Some of the samples increased up to 5 V. In the cycle measurement, the rate of decrease in capacity exceeded 20% after 250 cycles.
Research on influence of new structural design regulations on general design of steel towers
Authors: Fang Zhenggang , Li Zheng , Li Yigang , Liu Rui
Published: November 2022

This work describes the main revision content of the power industry standard (DL/T 5486-2020) (Technical specification for the design of steel supporting structures of overhead transmission line). And the effects of the new revision standard (DL/T 5154-2012) Technical code for the design of tower and pole structures of overhead transmission line (DL/T 5154-2012), on the general design of 35kV~750kV steel towers are analyzed in depth. Subsequently, the optimization suggestions of general design of the steel tower are proposed.