Last Subcode Neural Network Assisted Polar DecodingLiu, Hengyan; Zhang, Limen; Yan, Wenjun; Li, Yajie
doi: 10.1088/1742-6596/2356/1/012040pmid: N/A
A fast successive-cancellation decoding scheme based on neural network (NNFSCD) called last subcode neural network assisted decoding (LSNNACD) scheme for polar codes is proposed to improve decoding performance. First, a neural network node (NNN) is proposed and a neutral network model is trained to decode it. Then, the node recognizer is proposed to recognize a polar code with a NNN. Simulations with polar codes and binary phase shift keying (BPSK) shows good performance and low latency in the additive white Gaussian noise (AWGN) channel. Moreover, the proposed scheme has a wide application range.
Design and Implementation of EMU On-board Data Protocol Management SystemQiao, Chengzhen; Qiu, Yanzhi; Yang, Chunhui; Zhang, Shaozhe
doi: 10.1088/1742-6596/2356/1/012022pmid: N/A
In view of the problems of various types, frequent upgrades and inconsistent standards of WTDS on-board protocols and fault dictionaries of EMU, sort out various on-board protocol documents and fault dictionaries of EMU on the whole railway. Analyse the differences of various on-board protocols and fault dictionaries of multiple units of different vehicle types and batches, and study the unified and standardized management method. Design a EMU on-board data protocol management system with complete business functions, standard specifications, safety and reliability, and realize the functions of structuring the content of the protocol file, version of the protocol file, process management, etc., so as to provide data support for EMU data mining and PHM application.
Identification and Measurement of Positive and Negative Topological Charges of LG Beams for Medical CareGuo, Jianjun; Hassan, Shahbaz Gul; Lin, Lijun; Liu, Tonglai; Cao, Liang; Feng, Dachun; Liu, Shuangyin; Xu, Longqin
doi: 10.1088/1742-6596/2356/1/012005pmid: N/A
A medical care system’s security, high-capacity information transfer, and communication are all dependent on OAM-based quantum key distribution, namely on the measurement of OAM’s topological charges (TCs). The intensity patterns of interference between the vortex beam and its conjugate beam are analyzed to detect and evaluate positive and negative TCs of Laguerre-Gaussian (LG) vortex beams in a novel manner. An upgraded Mach–Zehnder (M-Z) interferometer is used to establish the order of positive, negative, integer, and half-integer TCs. Deciphering the order of integer TCs and half-integer TCs may be accomplished by measuring the interference bright petals as well as half of the total numbers of bright petals. The integer and half-integer TCs (VPP) may be modulated by the use of light path rotational with a vortex stage plate. Using the interferometer as mentioned earlier, the positive and negative of integer and half-integer TCs are acquired. Quantitatively, the order and sign of integer and half-integer TCs are measured in this manner. And this method is straightforward and less susceptible to the influence of parasitic interference. This can provide comprehensive security protection for the medical monitoring system, better reduce medical risks and protect patient privacy.
Optimised VMD based on Improved Grey Wolf for Human Pulse Wave CharacterisationYu, Chengbo; Mi, Youyu
doi: 10.1088/1742-6596/2356/1/012023pmid: N/A
To address the difficulty in determining the penalty factor α mode and number K for the Variational Mode Decomposition (VMD) human pulse wave signal, which makes it difficult to extract and analyse its features accurately, an Improved Grey Wolf Optimization (IGWO) method is proposed to optimise the VMD. In this paper, the optimal modal number K and penalty factor α in the VMD are determined by IGWO using Minimum Average Mutual Information (MAMI) as the fitness function. The proposed method is used to completely decompose the pulse wave into K Intrinsic Mode Functions (IMF), and the marginal spectral analysis of the decomposed modes is performed to calculate the spectral energy ratio. And the effectiveness of the proposed method is demonstrated experimentally.
Design of Wearable Multifunctional ElectroscopeMa, Di; Wang, Ning
doi: 10.1088/1742-6596/2356/1/012012pmid: N/A
With the development of science and technology, the principle and technology of non-contact electroscope are relatively mature and widely used. Therefore, the development of an electroscope with real-time monitoring, lightweight, portable and rich functions is of great significance to the safety of operators. In this paper, comparison of different sensors is used to determine the design of the monopole antenna. Then designing each module circuit and PCB, doing the hardware production of electroscope, writing software and debugging the system are completed. In order to facilitate maintenance monitoring, electroscope has wireless communication function, which can upload data to the monitoring platform APP through Bluetooth. In summary, the designed electroscope can realize the functions of near power early warning, time display, heart rate measurement and mobile app monitoring, achieve the expected purpose and requirements, and provide active and effective power safety protection for maintenance personnel in high voltage environment.
A Bibliometric Analysis and Visualization of Digital EconomyDai, Zhe; Jiang, Yuantao
doi: 10.1088/1742-6596/2356/1/012041pmid: N/A
Using bibliometrics and visual analysis methods, this paper conducts quantitative analysis on the research hotspots, and research types of Chinese and international digital economy related literature. Chinese research focuses on application and practice, while international research focuses on the intersection of technology and society; Chinese and international digital economy research is summarized as applied theoretical research, governance issue research and application scenario research, each of which is different.
Simulation Study of Infrared Transmittance Under Different Atmospheric ConditionsSun, Dongdong; Zheng, Haijing
doi: 10.1088/1742-6596/2356/1/012045pmid: N/A
This article analyzes the atmospheric transmittance in the infrared band under different atmosphere conditions based on the MODTRAN software. Firstly, the atmospheric transmittance in the infrared band under two different atmospheric types, cold-dry and warm-wet, are calculated. Subsequently, the effect of H2O, CO2 and O3 molecules on the atmospheric transmittance in the infrared band are analyzed. Secondly, the differences in atmospheric transmittance at different altitudes (troposphere, stratosphere, mesosphere, thermosphere) in the infrared band are calculated, and the effects of H2O, CO2 and O3, CH4 and N2 on atmospheric transmittance and their variation patterns are analyzed. Finally, the influence of different aerosol types on atmospheric transmittance is calculated and analyzed, mainly considering molecular scattering and five different types of aerosol scattering. Conclusion, i) The total atmospheric transmittance of cold-dry atmospheres is higher than that of warm-wet atmospheres. The main factors influencing the difference in atmospheric transmittance between the two are H2O and O3. ii) Atmospheric transmittance varies with altitude, with the most dramatic changes with altitude being in the troposphere and stratosphere. The factors that have a greater influence on the atmospheric transmittance in the troposphere are H2O and CO2; CO2, O3 and CH4 have great influence on stratospheric atmospheric transmittance; The atmospheric transmittance of the mesosphere has little change, almost 1. The fluctuation of its transmittance curve is mainly affected by O3; The atmospheric transmittance of thermosphere is almost 1; N2 has little effect on atmospheric transmittance. iii) The influence of molecular scattering on atmospheric transmittance is negligible, while aerosol scattering has a great influence on atmospheric transmittance; Aerosol scattering at 9 μm has the greatest influence on atmospheric transmittance. The research results of this paper have certain guiding significance for the design and performance evaluation of infrared systems under different application conditions.
Mechanical Model Analysis of Dust on the PV Panels Surface in Low Latitude and High Altitude Plateau AreaXiong, Changquan; Zhang, Yuning; Hui, Xiaoping
doi: 10.1088/1742-6596/2356/1/012006pmid: N/A
This work selected a PV power station located in the low latitude and high altitude plateau area of Sichuan, China, as the research object. The environment, climate, operation and maintenance status of the PV power station were investigated and the dust on PV panels was collected to measure its properties to analyse the source and composition of the dust. The results showed that the main component of the dust was SiO2 and the dust particles were relatively uniform in size and regular in shape but not uniform spherical particles. Meanwhile, EDEM-FLUENT simulation soft wares were employed to simulate the accumulation process of dust on the surface of PV panels at different wind speeds under the installation inclination of 25 degrees and 35 degrees, respectively. Furthermore, systematically analysing the force between the dust and PV panels, exploring the action modes of various forces and sorting out the dominant force were carried out for the establishment of a mechanical model for dust accumulation or dust removal. The force of dust in this PV power station mainly included gravity 10−9~10−8N, van der Waals force 10−9N, electrostatic force 10−9~10−11N and fluid force. Meanwhile, the larger particles almost accumulated in the front row of PV modules while the smaller particles can float farther with the wind. Finally, combined with the mechanical model of dust on the PV panel’s surface, dust’s adhesion process and accumulation mechanism were explained.
DCCTN: Deep Complex Convolution Transformer Network for Far-field and Low SNR Speech EnhancementSun, Chang; Qin, Bo
doi: 10.1088/1742-6596/2356/1/012036pmid: N/A
Single-channel speech enhancement has made great progress with the development of deep learning. Recently, some researchers predict the real and imaginary parts of the output respectively by deep complex convolutional networks and achieve state-of-art performance. Based on this, in this paper, we design a new network structure, called Deep Complex Convolution Transformer Network (DCCTN), which is dedicated to solving the problem of single-channel speech enhancement under the conditions of far-field and extremely low signal-to-noise ratio (SNR). First, based on the Deep Complex Convolution Recurrent Network (DCCRN), a two-stage transformer masking module is introduced to replace the recurrent network structure and better focus on the long-term correlation of speech. Secondly, the deep complex transformer structure and gaussian weight matrix are introduced to make the model more suitable for far-field and very low SNR scenarios. In the experiment, we mixed real far-field clean speech and noise to make training and test data sets. The experimental results show that in the target scene, DCCTN proposed has significantly improved speech-enhancement performance, compared to most of the latest methods.
Overall Design and Hardware Realization of Space Stargazing CameraXu, Dongdong; Wang, Xiaofeng; Zhu, Junqing; Du, Limin
doi: 10.1088/1742-6596/2356/1/012011pmid: N/A
In order to improve the accuracy of satellite attitude, a complete stargazing camera was designed using KAC-06040 CMOS digital image sensor. An optical system with a focal length of 1220mm, an F-number of 6.71, and a field of view of 0.84 degrees was designed. The electronics system uses FPGA as the core control device to control CMOS to output digital signals, and transmit the signals back to the satellite data transmission system through TLK2711. The star camera has two working modes of imaging and transmitting the threshold and coordinate information of the star point. Through the field imaging experiment, it can be known that the camera has fine imaging quality, strong transplantability and high reliability. Within the field of view, about 1.2 stars can be photographed, and stars of magnitude 9 can be observed at the same time, which can effectively assist the star sensor to work.