High-speed Transmission Research Articles

AXOIDS OF HOOKE’S JOINT

The analysis of literary sources devoted to the research and construction of cardan transmissions using the Hooke's joint showed that the peculiarities of the spherical movement of the cardan joint crosspiece are insufficiently covered. This is explained by the relatively small weight of the crosspiece, due to which it almost does not affect the dynamics of the cardan transmission. The need to take into account the mass-geometric parameters of the crosspiece and to analyze comprehensively its movement may arise during accurate calculations of high-speed cardan transmissions. In this case, it is convenient to consider the movement of the crosspiece as rolling without sliding of the moving axoid on the stationary axoid. This approach makes it possible to more fully investigate the peculiarities of the spherical movement of the crosspiece and gives a visual representation of the orientation of its instantaneous axis of rotation in fixed and moving coordinate systems. Based on this, this work is devoted to the construction of a kinematic model of the Hooke's joint crosspiece, the movement of which is considered as rolling without sliding of a moving axoid on a stationary one.
 As a result of the kinematic analysis of the Hooke's joint, the equations of the hodographs of the vector of the absolute angular velocity of the crosspiece in the fixed and moving coordinate systems were obtained, and the parameters of the fixed and moving axoids of the crosspiece of the cardan joint were determined. It is proved that the stationary axoid of the crosspiece of the Hooke's joint is an oblique elliptic cone with the apex in the center of the crosspiece, and its opposite generatrices, crossing the major axis of the guide ellipse, coincide with the axes of the drive and driven shafts of the joint. The moving axoid of the crosspiece is a closed conical surface with a variable opening angle, the maximum value of which is equal to twice the value of the interaxial transmission angle. With small values of the interaxial angle, which occur in the practice of using a single Hooke’s joint, a moving axoid can be approximately considered as a straight circular cone with a vertex in the center of the crosspiece and an opening angle equal to twice the value of the interaxial transmission angle. The error of this assumption increases rapidly with the increase of the interaxial transmission angle. The correctness of the obtained mathematical model was confirmed by computer modeling in the Autodesk Inventor environment.
 The obtained results can be used in the study of dynamic processes that occur in cardan transmissions using Hooke's joint.

MLP-mmWP: High-Precision Millimeter Wave Positioning Based on MLP-Mixer Neural Networks.

Millimeter wave (MMW) communication, noted for its merit of wide bandwidth and high-speed transmission, is also a competitive implementation of the Internet of Everything (IoE). In an always-connected world, mutual data transmission and localization are the primary issues, such as the application of MMW application in autonomous vehicles and intelligent robots. Recently, artificial intelligence technologies have been adopted for the issues in the MMW communication domain. In this paper, MLP-mmWP, a deep learning method, is proposed to localize the user with respect to MMW communication information. The proposed method employs seven sequences of beamformed fingerprints (BFFs) to estimate localization, which includes line-of-sight (LOS) and non-line-of-sight (NLOS) transmissions. As far as we know, MLP-mmWP is the first method to apply the MLP-Mixer neural network to the task of MMW positioning. Moreover, experimental results in a public dataset demonstrate that MLP-mmWP outperforms the existing state-of-the-art methods. Specifically, in a simulation area of 400 × 400 m2, the positioning mean absolute error is 1.78 m, and the 95th percentile prediction error is 3.96 m, representing improvements of 11.8% and 8.2%, respectively.

Effect of nano aluminum nitride filler on mechanical, thermal, and dielectric properties of the glass/mullite composites for low‐temperature co‐fired ceramic applications

AbstractMullite/glass/nano aluminum nitride (AlN) filler (1–10 wt% AlN) composites were successfully fabricated for the low‐temperature co‐fired ceramics applications that require densification temperatures lower than 950°C, high thermal conductivity to dissipate heat and thermal expansion coefficient matched to Si for reliability, and low dielectric constant for high signal transmission speed. Densification temperatures were ≤825°C for all composites due to the viscous sintering of the glass matrix. X‐ray diffraction proved that AlN neither chemically reacted with other phases nor decomposed with temperature. The number of closed pores increased with the AlN content, which limited the property improvement expected. A dense mullite/glass/AlN (10 wt%) composite had a thermal expansion coefficient of 4.44 ppm/°C between 25 and 300°C, thermal conductivity of 1.76 W/m.K at 25°C, dielectric constant (loss) of 6.42 (0.0017) at 5 MHz, flexural strength of 88 MPa and elastic modulus of 82 GPa, that are comparable to the commercial low temperature co‐fired ceramics products.

Methods and ways for improving the exchange of information in the flight control system

Taking into account the shortcomings of the information exchange system through the ARINC 629 bus, which is widely used in new digital avionics systems (delay of information exchange, program errors, sensitivity to external influences, etc.), the fiber-optic information exchange system proposed in the article reduces the weight of aircraft in aviation systems, it allows solving many problems such as software errors, delays and maintenance problems. This system has a much higher transmission speed than traditional systems, significantly reduces the number of computers and wires, and the transition to modular avionics makes it more compact and easier to maintain.

A Novel Wideband Common-Mode Noise Suppression Filter That Combines Mushroom and Defected Corrugated Reference Plane Structures

A novel wideband common-mode (CM) suppression filter is proposed for high-speed transmission. The filter is embedded in 3 10 mm × 10 mm layers of a printed circuit board (PCB) that combines a mushroom structure and a defected corrugated reference plane structure (MDCRP). Using the novel MDCRP structure generates more resonance frequencies in the CM current return path. This generates a wider CM noise suppression performance. We used a simulation method to obtain the best geometric parameters for the MDCRP structure. The experimental results proved that the full-wave simulation results were consistent with the actual measurement results. This novel filter shows good signal integrity according to actual measurements, and the insertion loss can be kept to less than −2.306 dB from DC to 21 GHz in differential mode (DM). The CM noise can be suppressed by over −10 dB from 5.09 GHz to 20.62 GHz. The fractional bandwidth is 120.8%, and the CM noise improves by 64.5%. An eye diagram proves that the filter can support a 20 Gb/s transmission rate with complete differential signal transmission capability. The MDCRP structure filter can support HDMI 2.0, PCI Express 4.0, USB 3.2, and SATA Express. Therefore, the filter meets current computer and server system products’ design needs.

Book recommendation and purchase of intelligent image recognition technology under the background of 5G environment

In addition to a more extreme network experience and larger network capacity, 5G can also be used to rapidly transmit massive global text data at higher transmission speeds and higher reliability than previous communication technologies, allowing more communication devices around the world to operate at a faster rate. The transmission speed is safe and reliable to connect with each other. The rapid development of image recognition technology will be more effective in improving the operational efficiency of various industries. At present, scholars have used 5G technology and image recognition technology in the field of book management. This paper designs a book image recognition recommendation scheme based on 5G technology, in order to improve the problems of inaccurate book sales targets and low book classification efficiency of merchants from various perspectives. The image recognition book recommendation system combined with 5G technology is mainly divided into two steps: image recognition and book recommendation. The ultra-high speed provided by 5G technology can greatly improve the speed and accuracy of image recognition. Significantly reduces program running time. This paper first analyzes the related concepts of 5G, image recognition and recommendation algorithm, then sorts out the book image recognition method, and then designs the book recommendation purchase method. Combined with 5G technology, the image recognition and recommended purchase strategy are optimized. Finally, an online questionnaire is used to investigate the merchants using this method. The survey results show that the merchants who use this identification and purchase recommendation method have better performance in book classification, book personality recommendation, customer loyalty and book sales rate have greatly improved.

Deep Learning for Waveform Level Receiver Design With Natural Redundancy

High-speed information transmission system demands more powerful communication receivers. In this paper, we integrate deep learning algorithms into constructing waveform level receiver, which is capable of harnessing natural redundancy (NR) in raw message sources. Owing to end-to-end learning paradigm of neural network (NN), the proposed NN receiver can accomplish joint symbol timing synchronization and demodulation based on oversampled waveform sequences directly. The prevalent bidirectional LSTM (BiLSTM) and Transformer structures, suitable for excavating sequential correlation of complex sources and waveform sequences, are considered as the backbone of NN receivers. Under the cases of clean label and noisy label, we conceive two novel training algorithms and interpret their principles in theory. The clean label bits are accessible from original source encoding schemes, while noisy label bits are available from the decision results of canonical receivers with independently noised waveform sequences. When noisy labels possess sufficiently small error rates, optimized NN receiver is competitive with that adopting the accurate labels. As for Markov sources and natural language text sources, simulation results show that the proposed NN receivers’ performances are superior to the classical receivers without a priori knowledge, especially when high spectral efficiency modulation schemes are encountered and random noise is significant.

Handover Experiment of 60-GHz-Band Wireless LAN in over 200-km/h High-Speed Mobility Environment

High-frequency wireless communication is drawing attention because of its potential to actualize huge transmission capacity in the next generation wireless system. The use of high-frequency bands requires dense deployment of access points to compensate for significant distance attenuation and diffraction loss. Dense deployment of access points in a mobility environment triggers an increase in the frequency of handover because the number of candidate access points increases. Therefore, simple handover schemes are needed. High-frequency wireless systems enable station position to be determined using their wideband and highly directional communication signals. Thus, simple handover based on position information estimated using the communication signal is possible. Interruptions caused by handover are also a huge barrier to actualizing stable high-frequency wireless communications. This paper proposes a seamless handover scheme using multiple radio units. This paper evaluates the combination of simple handover and the proposed scheme based on experiments using a formula racing car representing the fastest high-speed mobility environment. Experimental results show that seamless handover and high-speed wireless transmission over 200Mbps are achieved over a 400-m area even at station velocities of greater than 200km/h.

P‐8.8: High Performance Video Stream Codec for High‐speed Digital Transmission in Display Driver Chips

Nowadays, as the vivid visual enjoyment requiring in mobile display devices exploding everywhere, enormous bandwidth pressure lands in all high-speed digital transmission interfaces, such as HDMI, MIPI, DP, eDP etc. A low latency in pixels’ time, flexible implementation for circuits, and high performance in visual quality video stream encoder and decoder (FHP-Codec) is proposed to relax the stress. The image structural features are analyzed, which directs an accurate 1D or 2D prediction reducing the redundancy utmost compared with DSC by 10~20% benefit in entropy, without obvious increments in circuit area and power consumption. According to the benchmark in Kodak image suite, FHP-Codec shows a considerable cost-performance ratio for display driver application fields.

Service Delay Minimization for Federated Learning Over Mobile Devices

Federated learning (FL) over mobile devices has fostered numerous intriguing applications/services, many of which are delay-sensitive. In this paper, we propose a service delay efficient FL (SDEFL) scheme over mobile devices. Unlike traditional communication efficient FL, which regards wireless communications as the bottleneck, we find that under many situations, the local computing delay is comparable to the communication delay during the FL training process, given the development of high-speed wireless transmission techniques. Thus, the service delay in FL should be computing delay + communication delay over training rounds. To minimize the service delay of FL, simply reducing local computing/communication delay independently is not enough. The delay trade-off between local computing and wireless communications must be considered. Besides, we empirically study the impacts of local computing control and compression strategies (i.e., the number of local updates, weight quantization, and gradient quantization) on computing, communication and service delays. Based on those trade-off observation and empirical studies, we develop an optimization scheme to minimize the service delay of FL over heterogeneous devices. We establish testbeds and conduct extensive emulations/experiments to verify our theoretical analysis. The results show that SDEFL reduces notable service delay with a small accuracy drop compared to peer designs.

Filtered OFDM System Improvement Using Hamming Code

Orthogonal Frequency Division Multiplexing (OFDM) technique is widely adopted for broadband Forth Generation (4G) wireless communication systems at present, owing to its ability to combat multi-path interference. Nevertheless, it suffers from a large Peak to Average Power Ratio (PAPR) and Out Of Band Emission (OOBE), making it unsuitable for a high-speed transmission system. On the other hand, the Filtered-OFDM (f-OFDM) system is suggested to overcome the traditional OFDM system's disadvantages and maintain its advantages. Nowadays, the developments and growing communications systems are rapid, especially on their applications such as wireless networks, internet, satellite communications, mobile telephony, etc. This increases the demand for raising the bit rates with decreasing power consumption and the bit error rates (BER). In this paper, Hamming codes are proposed to improve the f-OFDM system performance, while the presence of the subband filter in system architecture could decrease the values of OOBE than the familiar OFDM system. The outcomes showed that utilizing interleaver with Hamming code considerably improves the proposed system performance, while the OOBE values were lower than the conventional OFDM system.

Массовая коммуникация как онтологический фон современной культуры

The article analyzes the history of the development of forms, methods and means of communication as one of the main factors in the civilizational development of mankind. The author agrees with M. McLuhan's periodization, supplementing it with specific characteristics of the current stage in the development of communication, which can be designated as mass communication. Among its constitutive features stand out: derealization, glocalization, individualization, publicity, the disappearance of intimacy and semantic involution. Communication is defined as a mode of existence of modern man and, more broadly, modern society. Identity, basic modes of activity, formats of existence – all this is somehow connected with mass communication, which has become the ontological framework of culture. New media allow a significant increase in the participation of their users, who are no longer passive recipients of information, but actively produce content and information. There is a negative trend of devaluation of traditional forms of communication, within which significant values were articulated and cultivated, contributing to the consolidation and solidarity of society. The question is raised about the possible threats of uncontrolled development of modern forms of culture based on a high speed of message transmission, which, in the author's opinion, leads to the disappearance of the option of deep reflection, the possibility of understanding at the level of the whole. Digitalization threatens the barbarization of society, its return to the state of the dark Middle Ages, when the value of personal and autonomous intentions is leveled, and thoughtless collectivity comes in their place.

Interband cascade technology for energy-efficient mid-infrared free-space communication

Space-to-ground high-speed transmission is of utmost importance for the development of a worldwide broadband network. Mid-infrared wavelengths offer numerous advantages for building such a system, spanning from low atmospheric attenuation to eye-safe operation and resistance to inclement weather conditions. We demonstrate a full interband cascade system for high-speed transmission around a wavelength of 4.18 µm. The low-power consumption of both the laser and the detector in combination with a large modulation bandwidth and sufficient output power makes this technology ideal for a free-space optical communication application. Our proof-of-concept experiment employs a radio-frequency optimized Fabry–Perot interband cascade laser and an interband cascade infrared photodetector based on a type-II InAs/GaSb superlattice. The bandwidth of the system is evaluated to be around 1.5 GHz. It allows us to achieve data rates of 12 Gbit/s with an on–off keying scheme and 14 Gbit/s with a 4-level pulse amplitude modulation scheme. The quality of the transmission is enhanced by conventional pre- and post-processing in order to be compatible with standard error-code correction.

A Collection and Retrieval of Intelligent Teaching Data for Higher Vocational Finance and Economics Major Based on External Data Interface Optimization

Firstly, it analyzes the requirements of the high-speed data transmission system, and then gives the design scheme of the bridge chip based on PCI EXPRESSS, including the logic design block diagram, interface description and bus timing. Higher vocational finance and economics majors mainly train high-skilled professionals in front-line management and service, and their professional characteristics of management and service put forward unique requirements for students' operational skills, professional ability and comprehensive quality. Aiming at the current teaching status of this course and some problems in the teaching process, under the guidance of the virtual learning situation teaching method, the corresponding solutions are put forward through the task-based teaching of the course knowledge points. Different from full-text crawling, distributed directional crawler requires fast crawling of deep and precise structured data from the Internet.

An analysis on the strategies of university education management under the background of new media era

With the advent of the Internet era, the forms of media continue to upgrade and evolve, and the rapid development of new media technology has ushered in the era of new media. The new media takes the Internet as the data platform to carry out the high-speed real-time transmission of information. In the era of new media, all walks of life have been affected to some extent, especially the university education management has brought profound impact, not only changes the way of education and teaching activities, but also provides a brand-new idea for education management. This paper will deeply explore the characteristics of new media communication, deeply analyze the existing problems in the current teaching management of colleges and universities, and provide scientific solutions, in order to look forward to better promote the management of college education in the era of new media.

Fiber-optic-based force and shape sensing in surgical robots: a review

PurposeWith the increasing development of the surgical robots, the opto-mechatronic technologies are more potential in the robotics system optimization. The optic signal plays an important role in opto-mechatronic systems. This paper aims to present a review of the research status on fiber-optic-based force and shape sensors in surgical robots.Design/methodology/approachAdvances of fiber-optic-based force and shape sensing techniques in the past 20 years are investigated and summarized according to different surgical requirement and technical characteristics. The research status analysis and development prospects are discussed.FindingsCompared with traditional electrical signal conduction, the phototransduction provides higher speed transmission, lower signal loss and the immunity to electromagnetic interference in robot perception. Most importantly, more and more advanced optic-based sensing technologies are applied to medical robots in the past two decades because the prominence is magnetic resonance imaging compatibility. For medical robots especially, fiber-optic sensing technologies can improve working security, manipulating accuracy and provide force and shape feedback to surgeon.Originality/valueThis is a new perspective. This paper mainly researches the application of optical fiber sensor according to different surgeries which is beneficial to learn the great potential of optical fiber sensor in surgical robots. By enumerating the research progress of medical robots in optimization design, multimode sensing and advanced materials, the development tendency of fiber-optic-based force and shape sensing technologies in surgical robots is prospected.

Vibration and cavitation in high-speed gears caused by faults

In high-speed gear transmission, cavitation occurs easily due to vibration. When gear has pitting or crack fault, the cavitation will be more violent due to stronger vibration, causing potential safety hazards. However, researches on gear cavitation mechanism considering pitting and crack are limited. For studying the cavitation mechanism of faulty gear, a model combined computational fluid dynamics and faulty gear dynamics has been proposed, being regarded as the innovation of this paper. The dynamic characteristics of the faulty gear is obtained by solving the gear finite element model, and the results will be applied to the analysis of lubricating oil flow characteristics as boundary conditions. For proving the validity of the proposed model, the simulation results are compared with the available experimental results. Moreover, the novelty of this paper is to consider the influence of gear failures on cavitation, factors such as rotational speed, pitting depth and crack depth are discussed, tooth profile changes are also considered. The results indicate that gear faults have greater impact on cavitation at high speeds. At 10,000 rpm, with the deepening of pitting, the cavitation intensity will increase firstly and then decrease. When the pitting depth increases from 0.2 mm to 0.3 mm, the root mean square value of average vapour volume fraction decreases from 0.0752 to 0.0724. For cracked gears, the crack depth will affect the cavitation enhancement rate. The increase rate of cavitation decreases from 17.4 to 1.1% when crack depth increases from 1 to 4.5 mm. This study provides an effective tool for gear cavitation suppression and high reliability.

Optimal Adaptive Waveform Design Utilizing an End-to-End Learning-Based Pre-Equalization Neural Network in an UVLC System

Visible light communication (VLC) has emerged as a promising communication method in the special field of 6G, such as intersatellite communication (ISC) and underwater wireless optical communication (UWOC). Green light-emitting diode (LED)-based underwater visible light communication (VLC) is considered a potential candidate for UWOC of mobile autonomous underwater vehicle (AUV) and remotely operated underwater vehicle, particularly in coastal and harbor environments. However, due to bandwidth limitations and variable underwater channels, implementing high-speed underwater VLC remains a challenge. In this paper, a neural network-based auto equalization model (NNAEM) using end-to-end learning is proposed to achieve a high-speed underwater VLC link with a bandwidth-limited green LED. The entire NNAEM includes a neural network-based channel model, a pre-equalization neural network, and a post-equalization neural network. Based on the data-driven channel model, our auto equalization (AE) method can dynamically pre-equalize the discrete multitone (DMT) modulated signal in different bandwidth-limited cases and various nonlinearity cases. An underwater VLC link with a data rate of 3.451 Gbps and a transmission distance of 1.2 m is experimentally demonstrated by employing the proposed NNAEM under the hard decision-forward error correction (HD-FEC) threshold of 3.8 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> . The data rate improvement is up to 30.4% compared to other advanced digital signal processing (DSP) methods. The scenario adaptation and robustness of the NNAEM are also verified in the experiments, which demonstrate that the NNAEM can serve an important role in underwater high-speed VLC transmission.

Visible-light-assisted activation of peroxymonosulfate (PMS) over CoOx @C/g-C3N4 composite for efficient organic pollutant degradation

As a promising advanced oxidation process, photo-assisted peroxymonosulfate (PMS) activation for wastewater treatment has attracted widespread attentions. However, rational design of synergetic and recyclable catalysts for PMS photo-activation remains a big challenge. In this study, a carbon layer-coated amorphous CoOx supported on graphitic carbon nitride (CoOx @C/g-C3N4) composite was fabricated to drive visible-light-assisted activation of PMS for efficient organic pollutant degradation. Amorphous CoOx nanoparticles were in-situ grown on two-dimensional g-C3N4 substrate, among which a carbon layer serves as a high-speed electron transmission channel, facilitating the separation of photogenerated electron-hole pairs and accelerating the Co3+/Co2+ redox cycle. Simultaneously, the carbon layer provides a protective film to suppress Co leaching, thereby improving the catalytic activity and reusability. Owing to the unique heterostructure and synergetic effect, the optimized 6% CoOx @C/g-C3N4 composite exhibits superior catalytic efficiency and excellent cycling stability towards the degradation of various organic pollutants, which displays nearly 100% elimination of tetracycline (TC) within 80 mins. The h+, SO4•- and •OH are determined as the main contributors in the visible light-assisted PMS activation system, and the possible catalytic mechanism is also proposed. This work demonstrates a feasible strategy for constructing synergetic and effective photo-activation PMS catalysts for water remediation.

Parametric modelling of vibration response for high-speed gear transmission system

In the process of dynamic modelling and vibration response simulation for the high-speed gear transmission system, complex structures with a high degree of freedom (DOF) often lead to very large calculation errors, especially under conditions with unpredictable internal and external excitations. In this paper, a novel parametric probabilistic regression (p-PR) model based on data-driven and parametric modelling theories are proposed for the vibration signals of the high-speed gear transmission system. Based on the proper orthogonal decomposition (POD) method, the dataset of vibration signals is constructed, and a new truncated parametric reduced-order model (PROM) of the dataset is given for the gear vibration, with the truncated modes and corresponding coefficient vectors obtained. Through training the PROM and operating parameters using probabilistic regression, maximum likelihood estimation, and the parametric mode reconstruction, the p-PR model of vibration data for the gear transmission system is established. To validate the parametric modelling theories and the p-PR model, a bevel gear transmission experimental rig and a vibration signal test system are built, and the constant-speed test (CST) experiment and speed-up frequency sweep (SUFS) experiment are conducted. Based on the results of the CST experiment, the p-PR model for the experimental system is established and compared with the SUFS results. Results show that the p-PR model can accurately predict the vibration signals in both the time-domain and the frequency-domain, and the maximum predictive error for the experiment is 7.8%, which validates the accuracy and feasibility of the proposed theories and methods.