bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compression AutoEncoder for High-Resolution Ocean Sound Speed Profile Data
Authors: Liang Zhenyu , Chen Letian , Xiao Wenbin 
Published: March 2024

Abstract
High-resolution ocean sound speed profile (HROSSP) data is essential for ocean acoustic modeling and sonar performance evaluation. However, the large volume and storage requirements of this data severely restrict its practical application in ocean acoustics. In this paper, we propose a compression autoencoder specifically designed for managing HROSSP data (CAE-HROSSP) and investigate the optimal network structure. Experimental results demonstrate that by using the min-max normalization method for input data and the corresponding inverse normalization for output data, along with employing the LeakyReLU function as the final activation layer, the accuracy of decompressed data reconstruction can be significantly improved. To tackle the challenges of fitting the distribution of surface sound speed data caused by significant variations and noise, we propose two loss functions: slice mean square error and elemental mean square error. These loss functions are combined with mean squared error through weighted summation to enhance CAE-HROSSP’s ability to fit the distribution of surface sound speed values and minimize the reconstruction errors of compressed data. Performance evaluation experiments reveal that CAE-HROSSP outperforms two existing methods in compressing HROSSP data, achieving superior performance with smaller data reconstruction errors at higher compression ratios. Furthermore, transfer learning is utilized to enhance the training of CAE-HROSSP, employing HROSSP data from the area where the mesoscale eddy is situated, as well as at the convergence of cold and warm ocean currents. The compression performance of both the training set and the validation set is comparable in the sea, where the structure of the sound speed profile varies greatly. This indicates that CAE-HROSSP can compress highly variable sound speed profile data in more sea areas using transfer learning, and has the potential to be extended globally. The findings and insights obtained from this study provide guidance for future endeavors in utilizing autoencoders to compress HROSSP data.
Study of the strength characteristics of particle velocity at the seabed interface
Authors: Xie Jinhuai , Cao Dejin , Zhang Haigang 
Published: March 2024

Abstract
When studying the propagation characteristics of the acoustic vector field, the law that the horizontal particle velocity intensity is stronger than the vertical particle velocity intensity does not apply near the seabed interface. To verify this characteristic, a sea experiment was conducted in the South China Sea to obtain the long-range propagation data of particle velocity at the seabed interface. Then, based on the normal mode method, the particle velocity intensity distribution of different types of seabed is theoretically simulated and compared with the experimental data, and the intensity characteristics of particle velocity at the seabed interface are verified. The results show that the particle velocity strength of the elastic seabed is mainly influenced by the submarine shear wave, which leads to the phenomenon that the vertical particle velocity is stronger than the horizontal particle velocity strength, and the relative strength of the two is determined by the compression wave velocity, the shear wave velocity and the seabed density.
Phenomenon of reverberation intensity oscillation observed in shallow-water reverberation experiment
Authors: Li Gongyun , Gao Bo , Pang Jie 
Published: March 2024

Abstract
Reverberation has always been a disturbance for active sonar. In the Yellow Sea reverberation experiment conducted in July 2014, the motion of the soliton internal wave was recorded by the temperature sensor attached to the vertical array. The effect of the soliton internal wave on reverberation was investigated from both the temperature chain and the reverberation static experiment. Through the processing of the data in this section, it is found that the soliton internal wave can cause the generation of clutter and the oscillation phenomenon of the average reverberation intensity, and the subsequent research can realize the acoustic telemetry to forecast the internal wave and further improve the performance of the active sonar.
Study on the inductively coupled high rate system and long-distance transmission
Authors: Wu Sheng , Huang Yifeng , Zhang Pingping , Jiang Nian , Liu Chao , Li Lulu , Zhang Cheng , Hu Zechen 
Published: March 2024

Abstract
The inductively coupled transmission chain can carry multiple Marine sensors, which is an important means to obtain Marine data, but the current transmission rate of inductively coupled data is low, which can not meet the needs of future Marine data transmission. The induction coupling system designed in this paper adopts the structure of double magnetic loop and a double-winding, and adopts the new single frequency different code algorithm to realize the data transmission rate of 150kbps. Different water environments were set up in the laboratory for testing, and the lower bit error rate was found in the water environment with the ion concentration of 10%-35%, which met the requirements of inductive coupling data transmission in a multi-water environment. It is of great significance to establish the research of underwater inductively coupled long-distance transmission for the subsequent design of a new inductively coupled transmission chain and the improvement of the data transmission rate.
Frequency estimation of underwater acoustic targets based on improved FRI method
Authors: Wang Xin , Guo Longxiang , Sun Hui 
Published: March 2024

Abstract
The line spectrum information of a ship’s radiated noise signal is often regarded as an important feature used to distinguish between targets. In this paper, an improved FRI (finite rate of innovation) method is proposed to estimate the low-frequency line spectra of the radiated noise from underwater acoustic passive targets under the condition of finite sampling points. First, a preliminary rough estimation of the frequency is performed using the Fourier transform. Then, the multichannel signal data are iteratively fitted based on the polynomial-ratio form model. The optimal estimation results are finally determined based on the residuals between the data and the model in the fitting process. Simulation experiments prove that compared with the original FRI algorithm, the method proposed in this paper can estimate line spectral frequency more efficiently under the condition of low signal-to-noise ratio (SNR), and can achieve fast convergence with shorter operation time. The experimental data processing results prove that the method can realize high-precision extraction of line spectrum information of ship noise.
Research on rapid detection of characteristic parameters of aeroengine blade surface based on laser scanning
Authors: Song Junfang , Sun Bin , Wang Tengjiao , Deng Huauyou 
Published: March 2024

Abstract
How to detect and evaluate the profile quality of aeroengine blades and provide technical support for blade manufacturing has become one of the key technical problems in the field of aviation manufacturing quickly and effectively. This paper studies the evaluation criteria of medium surface quality in the processing and manufacturing process of aeroengine blades, optimizes and innovates the fast extraction algorithms of various geometric parameters such as aeroengine blade section line, middle arc, front/rear edge center, front/rear edge radius, blade chord length, and chord angle, and establishes the evaluation criteria of aeroengine blade surface. According to the geometric relationship of blade chord length and front/rear edge radius in the blade section profile, the parameters are solved one by one through an optimization algorithm, combined with non-contact laser scanning measurement, and the blade detection efficiency is improved by more than 40%.
Research on the UOSM four-port Calibration algorithm and determination method of the Transmission error term
Authors: Du Jinghui , Chen Xiaolong , Wu Jianqiu , Wang Yingquan 
Published: March 2024

Abstract
As one of the key techniques for vector network analyzers to achieve high precision measurement, calibration, and error correction technology has always been the focus of continuous exploration and innovation. UOSM calibration algorithm uses unknown straight-through transmission standards that do not need to be defined and known open-circuit standards, short-circuit standards, and matching standards to calibrate microwave and millimeter wave bands. Based on the study of the mature UOSM calibration algorithm, this paper proposes a method of self-calibration and comparison of the measurement data based on the unknown cut-through standard, which no longer needs the group delay parameters of the unknown straight-through standard and reduces the dependence on the calibrator. The accuracy of the algorithm and error item determination method is verified by ADS simulation and instrument actual test, and a good calibration effect is achieved. It is proved that the algorithm has the ability of accurate calibration. Due to the reduction of parameters, the stability and applicability of the algorithm are improved.
Simulation and experimental study of die-casting pickup robot
Authors: Chen Chaoda , Lv Zhisheng , Yu Zhuoyuan , Xu Biaoqing , Xie Junxian , Luo Yayuan 
Published: March 2024

Abstract
To improve the efficiency of die-casting machine pickup, the combination of SolidWorks and RobotStudio is proposed to establish a simulation workstation. In this paper, the key mechanism analysis and design of the die-casting machine pickup robot are used to determine the robot body and end-effector. SolidWorks three-dimensional software is used for die-casting pickup robot’s overall mechanical structure and workstation peripheral equipment modeling. The RobotStudio software is used for the corresponding model planning layout and Smart components to write to achieve die-casting robot workstation efficient pickup work program writing and simulation debugging. Experimental results show that the die-casting machine pickup robot completed the pickup behavior. The system has the advantages of fast response speed, high positioning accuracy, and reliable operation, effectively improving the efficiency of the production line.
Research on extremely weak remanence measurement system
Authors: Xu Chaoqun , Sun Tian , Huang Kui , Xiao Qi 
Published: March 2024

Abstract
To accurately obtain the extremely weak magnetic field information of the test piece, this article first introduces the basic principles of the extremely weak residual magnetic field measurement technology. Then, an ultra-high precision magnetic shielding system has been developed, which is made of high permeability materials and equipped with a demagnetization coil system, and it can regularly eliminate the inductance of the entire shielding system. The effective shielding inner diameter of the magnetic shielding system is 0.8 m, the length is 1.6 m, and the magnetic field resolution is 0.0015 nT. This system can provide strong support for the measurement of extremely weak magnetic fields in materials and biomedical magnetic research.
Hydraulic fault prediction of integrated transmission system based on LSTM
Authors: Liu Xiongjun , Jin Yuwen , Yao Shuai , Hao Chuangbo , Zhang Jinle , Xu Yi 
Published: March 2024

Abstract
Integrated drive-line fluids play a role in transmitting torque, providing control pressure, lubrication, and cleaning in the integrated drive-train. The increase of oil abrasive particles will accelerate the wear rate of rotating parts, while insufficient oil will lead to rapid ablation and gluing of rotating parts. According to statistics, more than 75% of hydraulic equipment failure is caused by oil pollution. Oil pollution leads to filter blockage which will cause fatal failure so that the entire transmission system cannot work. Therefore, it is extremely important to predict the fault and health management of the hydraulic system. This paper studies the oil fault of the integrated transmission system, proposes a data preprocessing method, and solves the problem of difficult extraction of deterioration index in the multichannel strong noise signal of the hydraulic system through the information fusion algorithm and the mean smoothing algorithm. According to the abnormal data judgment criterion based on the sliding window, the identification of the early fault starting point of the hydraulic system is realized, which provides a basis for the start-up fault prediction and the division of normal and degraded states. A multi-channel fusion fault prediction algorithm for hydraulic systems based on a Long-Short Term Memory (LSTM) deep network is proposed, which realizes long-term and high-precision fault prediction of hydraulic systems. Finally, the oil failure prediction algorithm of the integrated transmission system is verified by using real vehicle fault data.
A robust estimation method of GNSS/IMU fusion kalman filter
Authors: Pu Yanyan , Liu Shihuan 
Published: March 2024

Abstract
Aiming at the traditional gross error detection method of GNSS/IMU fusion Kalman filter, which simply retains or eliminates abnormal observation data and does not make full use of useful observation information, a new robust estimation method of Kalman filter is proposed. Based on the chi-square statistical hypothesis test, this method constructs continuous change measurement using weight coefficient, fully excavates measurable innovation between normal value and abnormal value, and establishes a new measurement update equation of Kalman filter robust estimation. Finally, through GNSS/IMU integrated navigation simulation, the advantages of the new Kalman filter are verified: no parameter adjustment is required, and the statistical error fluctuation is smaller than that of the traditional adaptive filter.
Experimental research on instrumentation for measuring automotive exhaust particle concentrations
Authors: Li Yuanhao , Li Guangze , Chang Liuyong , Zhou Quan 
Published: March 2024

Abstract
Due to the absence of domestic automotive exhaust measurement methods, this paper, based on the principle of condensation nucleus growth counting, has developed a nanoparticle counter suitable for automotive exhaust detection. The paper incorporates the peak value counting method and conducts comparative experiments between different counting methods of the nanoparticle counter and the results obtained by electrostatic counting, as well as parallel experiments with a TSI CPC. The following results were obtained: (1) Compared to the traditional rising edge counting method, the peak value counting method significantly improves counting accuracy. (2) When the concentration is below 12, 500 P/cc, the peak value counting method can count more particle signals. (3) In the testing of complex particle clusters in automotive exhaust, the nanoparticle counter can be used for measuring automotive exhaust emissions.
A method of liquid refractive index measurement based on image correlation coefficient
Authors: Xie Xinxin , Chen Junyi , Zhou Mengna , Xu Junjiang , Zheng Zijian , Yang Jiayao , Luo Jinming , Zhong Yuancong 
Published: March 2024

Abstract
According to the difference of speckle image caused by the axial displacement due to the refraction of a transparent medium, the liquid refractive index is measured by using the image correlation coefficient. An optical measurement system based on laser speckle is built into the experiment. Firstly, the CCD camera is adjusted to move along the optical axis in air, and multiple speckle images at different positions are collected, which are correlated with the speckle image at zero position to obtain the image correlation coefficients, and then the exponential calibration relation between the correlation coefficient and the axial displacement can be obtained. Secondly, two speckle images are collected when the laser speckle spreads respectively through the liquid to be measured and water as the internal standard, and the correlation coefficient between them is calculated. Finally, according to the above calibration relation, the corresponding axial displacement between the liquid to be measured and water can be derived, and then the refractive index of the liquid to be measured is calculated using the axial displacement formula. The results show that this method can realize the measurement of liquid refractive index, and the optical structure is simple and easy to operate.
Geometric calibration of the linear-array whiskbroom optical satellites based on look-angle corrections
Authors: Sun Yuanyuan 
Published: March 2024

Abstract
Linear-array whiskbroom optical satellites are equipped with scanning mirrors and compensation mirrors. They rotate and scan imaging with the satellite flight orbit as the rotation axis, and geometrically splice the scanned images along the orbit, achieving a balance between large width and high resolution of remote sensing images. The addition of scanning mirrors and compensation mirrors necessitates multiple reflections for the imaging ray to reach the focal plane. Hence, the calibration of the geometric aspects for linear-array whiskbroom optical satellites will be an intricate procedure. A geometric calibration model based on look-angle corrections is established according to the imaging characteristics of linear-array whiskbroom optical satellites. All errors are corrected using correction quantities, and cubic polynomial surfaces are used to fit correction quantities. The proposed geometric calibration method based on the look-angle corrections has a sensor positioning precision of better than 1.0 pixels for the calibrated image.
Application of particle filter algorithm in satellite positioning and navigation system
Authors: Ye Fangbin , Xiang Yingjie , Jiang Chi , Wang Jinrong , Wang Taoyue 
Published: March 2024

Abstract
To understand the application of satellite positioning and navigation system, the application of a particle filter algorithm in satellite positioning and navigation system is studied. In this paper, firstly, the state equation of the system is established according to the correlation between the parameters of GPS output, and the particle filter algorithm is applied to filter the GPS-received data. In the CPS navigation system, DSP is used to decode and filter the output signal of the CPS receiver. The results show that when the GPS signal is disturbed, the particle filter algorithm can deal with the abnormal observation samples well, which shows that it can reduce the computational complexity and improve the GPS positioning accuracy, and have a certain robustness.
The effect of crystal phase noise on the proton precession magnetometer magnetic field measurement accuracy
Authors: Zhang Cheng , Bo Tao , Chen Aimin , Luo Wang , Dong Haobin 
Published: March 2024

Abstract
The proton precession magnetometer is a crucial piece of equipment for measuring magnetic fields because it can determine the value of the magnetic field by measuring the frequency of the Free Induction Decay (FID) signal. The frequency source, one of the crucial parts of the frequency measurement system, has a direct impact on how well the system works as a whole. The communication quality and detection accuracy of the frequency measuring system are directly influenced by phase noise, which is a crucial indicator of frequency stability. By acquiring various output frequencies of crystal oscillators using the Phase Locked Loop (PLL) frequency doubling technique, this study investigates the extent to which crystal phase noise impacts the accuracy of magnetometer frequency measurement.
Thermal error modelling of gear measuring instrument based on principal component regression
Authors: He Dongfeng , Wang Jianhua , Ren Yanping 
Published: March 2024

Abstract
As gear measuring instruments (GMI) are frequently used at the production site, the influence of temperature on their accuracy and stability becomes non-negligible. The existing standards and technologies only consider the error modelling and compensation problem when the GMI is in a uniform temperature field and is not suitable for the production site environment with a large temperature change rate and large temperature gradient. The paper delves into the problems of GMI thermal error modelling at the production site. First, the temperatures of the GMI and its surroundings were measured using multiple temperature sensors. The parallelism thermal errors between centres and the Z-axis (referred to as parallelism thermal errors) and the y-direction spatial thermal errors (referred to as spatial thermal errors) were also measured by the probe and laser interferometer synchronously. Then, the models of them were established based on principle component regression (PCR). As evidenced by the experimental results, the fitting determination coefficient of the models are both greater than 97%, and the prediction determination coefficient is greater than 90%, demonstrating that the models are precise and robust.
A multifunctional reference torque standard machine
Authors: Yi Wei , Qiu Dongli , Liu Ying , Yuan Guihong , Dai Hua , Li Shiqian 
Published: March 2024

Abstract
In response to the problem of using different single machines to achieve measurement and detection of existing torque instruments, this article introduces a multifunctional reference torque standard and proposes specific steps for torque measurement and detection. This standard machine can be used to detect various existing torque instruments and can solve the problem of using a single machine to achieve the detection of a certain type of torque equipment. After adopting this standard machine and its detection method, experimental data shows that the measurement of the torque transducer can meet the requirements of JJG995-2005 “Static Torque Measuring Machines” and the measurement of the reference torque wrench can meet the requirements of JJG1103-2014 “Reference torque wrench Verification Regulations”.
Testability evaluation of radar equipment with improved matter-element extension method
Authors: Chen Jiajun , Hu Bing , Shi Duanyang , Min Zhuo 
Published: March 2024

Abstract
In response to the problems of many influencing factors and different indexes, a radar equipment testability assessment index system is constructed based on the characteristics of equipment and testability connotation requirements. The Criteria Importance Though the Intercrieria Correlation (CRITIC) method is improved by using the variance coefficient to replace standard deviation and conflict coefficient to calculate the absolute value, and the objective weights of evaluation indexes are determined. An improved matter-element extension model is established, and the testability evaluation of different types of radar equipment is obtained by calculating the asymmetric close degree of the extension set. The effectiveness of the model is verified by an example analysis.
Dynamic characteristics for 2 μm-self-similar pulse thulium-doped fiber laser
Authors: Liu Weici , Li Xingxing , Lin Zhenguo 
Published: March 2024

Abstract
A passive mode-locked thulium-doped fiber laser is a generator for 2 μm ultra-short laser pulses. In addition, mode-locked self-similar pulses also exhibit rich nonlinear dynamic characteristics in thulium-doped fiber lasers. Therefore, this article studies the dynamic characteristics of self-similar pulses for the 2 μm passive mode-locked thulium-doped fiber laser. The research results also indicate that as the gain coefficient increases, the peak power of self-similar pulses increases, pulse width widens, and the linearity of chirp increases.