Synchronous System Research Articles

Notes on Verbal Aspect in Three Vedic Prose Narratives

AbstractThis article summarises the synchronic system of verbal aspect manifest in three Middle Vedic prose narrative texts, investigating the use of various morphological categories with past reference (especially the imperfect, perfect and aorist). I show that the imperfect and perfect are both compatible with multiple aspectual readings (perfective, imperfective and anterior); in the terminology of Dahl (2010), both may have neutral aspect. The aorist is largely restricted to anterior readings but can be perfective. Additionally, I consider the diachronic context of this system, outlining differences from the earlier one visible in the Early Vedic of the Rigveda and discussing the probable diachronic trajectory connecting the two. After commenting on the possibility of characterising the synchronic system within the alternative framework of Altshuler (2014), which lacks the category of neutral aspect, I conclude with notes on the use of the sentential particles ha, nu and vai in the text samples. The first of these seems to be associated with perfective aspect, while the latter two are both associated with anterior aspect.

Analysis of temperature rise of low temperature adiabatic oxidation of sulfur-containing “coal-like substances”

ABSTRACT Spontaneous combustion of coal is one of the main natural disasters in the process of coal mining, and spontaneous combustion of sulfur-containing coal is an urgent problem to be solved. In order to understand the influence of different sulfur structures and sulfur content on spontaneous combustion tendency of coal, the self-developed synchronous temperature compensation adiabatic oxidation experiment system was used to study the oxidation self-heating performance of a series of sulfur-containing “coal-like materials.” Through the analysis of the heating rate of coal containing specific sulfur structure, it is considered that the time of adiabatic oxidation temperature of different organic sulfur “coal” to rise to 70°C is dimethyl sulfoxide > phenylene sulfide > dibenzothiophene. By analyzing the oxidation temperature rise characteristics of organic sulfur models with different sulfur contents, it is believed that the higher sulfur content, the faster the low temperature oxidation reaction of “coal-like substance,” the faster the temperature rise rate, and the shorter the time to reach the uncontrollable self-heating temperature, so the shorter the spontaneous combustion period. In general, in the stage of low temperature oxidation, active sulfur containing small molecules (dimethyl sulfoxide) promote the oxidation temperature rise, stable structure, larger molecular weight of dibenzothiophene slow down the “coal-like” oxidation temperature rise.

A new passive‐based active disturbance rejection control for PMSG system with saturation constraints

AbstractThe disturbance in wind energy conversion system has a serious negative impact on the maximum power tracking performance of the system, and the saturation constraint problem also seriously restricts the stability of the control system. Therefore, a novel model compensation passive‐based active disturbance rejection control strategy is proposed to suppress the disturbance and saturation constraints, thus improving the tracking performance of the permanent magnet synchronous generator system in this paper. Taking advantage of the fact that active disturbance rejection control technology can estimate and compensate for the disturbances of the system in real time, a model compensation active disturbance rejection control method is proposed to make the system more robust to the changes in its own parameters and external disturbance. At the same time, the control input signal of the controller is given. A model compensation passive‐based active disturbance rejection controller is designed by using the passive control method, and the nonlinear sector method is introduced to solve the saturation constraint problem of the system. Simulation results show that the control strategy can effectively reduce overshoot, improve the system's response speed, have a good anti‐interference ability, and effectively suppress the influence of saturation constraints on the system.

Signal frame reception synchronization system with LoRa-modulated

Signal frame reception synchronization system with LoRa-modulated

Lower boundary capacity estimations of frequency-selective communication channels with PAM-n-signals achievable using resolution time theory

The issue of ensuring high specific capacity of promising wire telecommunication systems is one of the key problems of the last decade. At the same time, despite the existing spectrally efficient modulation methods that are used in existing communication systems, the majority of leading researchers associate further solution of this issue with the transition to the mode of information transmission at a rate "Faster-than-Nyquist" rate (FTN), in which the information receiving about the channel symbol occurs with pronounced intersymbol interference. In turn, this causes difficulties in the practical implementation of the receiver when using optimal signal processing algorithms with nonpolynomial computational complexity, and in the case of suboptimal demodulation methods implementing various types of channel equalization, due to conceptual limitations cannot provide a wide coverage of speeds in this mode. In this regard, the study of an alternative approach to processing signals with multi-position PAM-n-signals on the output of baseband frequency-selective channels (FSC) is relevant. The object of this paper is the study of the possibilities offered by the theory of resolution time for baseband FSC of the, in which information is transmitted using the PAM-n-signal, in the FTN mode. A modified mathematical model of FSC is presented, thanks to which analytical expressions are obtained for estimating the specific capacity in terms of the low bound capacity estimation introduced by Sh. Shamai, expressions for estimating the BER, including the case under the action of destabilizing factors on the symbol synchronization system. Auxiliary capacity estimations and rules for calculating the conditions for achieving them are introduced, convenient for engineering analysis. By means of numerical simulating for the most typical conditions inherent in wired FSC, which are modeled in this work by Chebyshev filters with ripple level of 3 dB and Butterworth filters, it is shown that in the FSN mode with a S/N ratio of no more than 40 dB and instability of the symbol synchronization system operation of 2.5% of the channel symbol duration with a bit error probability of 10–12, it is possible to expect a specific capacity of 5.7–8 bits/Hz*s. It is shown that these results are achieved by using hybrid forms of partial pulses. Recommendations for choosing a partial pulse shape are presented, their main properties are studied from the point of view of their engineering application.

Adaptive Speed Regulation for Permanent Magnet Synchronous Motor Systems With Speed and Current Constraints

Adaptive Speed Regulation for Permanent Magnet Synchronous Motor Systems With Speed and Current Constraints

Design of Pulse and Respiratory Signals Detection System

A pulse and respiration synchronous detection system is designed to explore the changes of physiological signals in different situations. The system obtains the corresponding signal through STM32 control pulse and respiratory acquisition circuit, calculates and displays real-time parameters such as heart rate and respiratory rate, and transmits the data to the upper computer for storage in the database. The experimental test results show that the system can monitor pulse and respiratory waveform in different situations, and the waveform is in good condition. Compared with medical pulse oximeter, the error of measured heart rate and blood oxygen concentration is less than 3%, and the error of respiratory rate is less than 5% compared with the actual value, which verifies the accuracy of system signal acquisition. The system is small in size, low in cost, and comfortable to wear, and can be applied in experimental research related to pulse and respiratory signals.

Функциональная модель объединенного источника комплексной системы синхронизации и доставки шкалы времени для крупной и распределенной системы технологического назначения

Purpose: to develop scientific and technical proposals and requirements for building sources of synchrosignals and messages of a single time for the integrated system of synchronization and delivery of the time scale depending on the requirements in frequency-time support signals and the current communication chain architecture in the framework of solving a unified synchronization system in phase time and the frequency in large territorially distributed and industrial technological systems. Methods: the applied research methods include the fundamental provisions of the theory of constructing synchronization systems, as well as infocommunication systems and networks. Results: a functional model of a united source of the integrated system of synchronization and delivery of the time scale, which includes a complete set of elements to perform the functions of synchronization and delivery of single-time signals in existing and promising complex heterogeneous networks with various architecture and heterogeneous equipment that differs from the existing fully taking into account the existing ones in Currently, technologies for delivery of single time and frequency signals, both on the basis of switching packages and on the basis of switching of channels. The proposed functional model of the united source of the integrated system of synchronization and delivery of the time scale will allow to reasonably approach the design of the means of transmitting and delivering single time and frequency signals to various and heterogeneous communication networks, taking into account all the needs for frequency-time support signals and limiting existing communication networks. Practical significance: the use of sources of single-time and frequency signals, which are based on the proposed functional model, will ensure a flexible infrastructure to ensure the unity of the unity of the unified time and clock network synchronization necessary for the correct functioning of communication equipment; Satisfy the requirements of synchronization signals and uniform messages for promising and existing consumers as much as possible; ensure the possibility of a phased transition of the construction of communication networks from the technologies of the channels to the technology of switching packages due to flexibility in the use of routes and transmission systems necessary for the spread of synchrosignals and uniform messages.

Web-Based Monitoring and Synchronization of Lecturers SKS Information System (Case Study of Muhammadiyah University Cirebon)

Institutions of higher education are increasingly embracing technology to enhance administrative processes and improve efficiency. This study presents a case study conducted at Muhammadiyah University Cirebon, focusing on the development and implementation of a web-based monitoring and synchronization system for lecturer SKS (Sistem Kredit Semester) information. The system aims to streamline the process of monitoring lecturer workload and credit distribution, thereby optimizing academic resource allocation. Through a combination of qualitative and quantitative research methods, including interviews, surveys, and system evaluation, this study examines the effectiveness and user satisfaction of the implemented system. Findings indicate significant improvements in administrative efficiency, transparency, and data accuracy. Moreover, feedback from users demonstrates a high level of satisfaction with the system's usability and functionality. The study contributes to the body of knowledge on the application of web-based systems in academic institutions and provides insights for similar implementations in other contexts.

Defect Identification of XLPE Power Cable Using Harmonic Visualized Characteristics of Grounding Current

This paper proposes an online monitoring and defect identification method for XLPE power cables using harmonic visualization of grounding currents. Four typical defects, including thermal aging, water ingress and dampness, insulation scratch, and excessive bending, were experimentally conducted. The AC grounding currents of the cable specimens with different defects were measured during operation. By using the chaotic synchronization system, the harmonic distortion was transformed into a 2D scatter diagram with distinctive characteristics. The relationship between the defect type and the diagram features was obtained. A YOLOv5 (you only look once v5) target recognition model was then established based on the dynamic harmonics scatter diagrams for cable defect classification and identification. The results indicated that the overall shape, distribution range, density degree, and typical lines formed by scatter aggregation can reflect the defect type effectively. The proposed method greatly reduces the difficulty of data analysis and enables rapid defect identification of XLPE power cables, which is useful for improving the reliability of the power system.

A laser field synchronous scanning imaging system for underwater long-range detection

A novel underwater optical imaging system is proposed to improve underwater image degradation, which is severely deteriorated due to absorption and scattering under artificial illumination. The light source employs a line laser with 520 nm wavelength and a mirror galvanometer that controls the one-dimension scanning of the laser beam to form a planar illumination light field. The camera adopts an sCMOS image sensor with an electronic rolling shutter exposure pattern, compressing the camera’s instantaneous field of view(IFOV) into a narrow strip by reducing the exposure time. Meanwhile, the system controls the light source to irradiate the IFOV of the camera only synchronously, which significantly compressed the overlapping volume of the light path between the camera and the light source so that the backscattered light captured by the camera was dramatically reduced. Experimental results at different turbidity and distances in pool environments show that the laser field synchronous scanning imaging system obtains excellent performance in contrast ratio (CR) and contrast signal-to-noise ratio (CSNR). In the turbidity experiment, the peak CR of the target image improved by a factor of 3.88, and the peak CSNR improved by a factor of 2.33 in 19.6 FTU. In the distance experiment, the peak CR of the target image improved by a factor of 5.57, and the peak CSNR improved by a factor of 1.67 at a distance of 13 m, achieving a clear imaging range of 15 m. This system substantially diminishes the impact of light backscattering on imaging quality, which effectively facilitates further development of the underwater task and renders the system highly applicable in underwater imaging.

Projective synchronization for distinct fractional-order neural networks consist of inconsistent orders via sliding mode control

The present study delves into the projective synchronization for distinct fractional-order neural networks consist of inconsistent orders, employing the principles of sliding mode control and incorporating fractional operators within the controller. Firstly, incorporating the fractional-order derivative into the controller facilitates the derivation of a synchronous error system, and a well-suited integral-type sliding switching surface is subsequently constructed, along with the development of an appropriate sliding mode controller, thereby ensuring the existence of sliding movement derived from the principle of sliding mode control. Then through the application of the Lyapunov direct method, it is shown that the sliding mode controller steers the evolution of error system towards the designated sliding switching surface and maintains therein indefinitely, meanwhile, novel criteria for achieving projective synchronization for distinct fractional-order neural networks consist of inconsistent orders is established. Lastly, to exemplify the efficacy and practical applications of the proposed approach, simulations with two types of distinct fractional-order neural networks are carried out utilizing a continuous frequency distribution model.

Fractional-Order PID Control of Permanent Magnet Synchronous Motors Based on Based on Improved Squirrel Algorithm

An adaptive differential squirrel algorithm fractional order PID controller is proposed to address the problems of instability and poor accuracy of Permanent Magnet Synchronous Motor PID control systems. In order to improve the global optimisation of the squirrel search algorithm, the crossover operation of the difference algorithm was combined, adaptive predation probability factor, dynamic crossover probability and Gaussian distribution perturbation operation are added to the squirrel search algorithm to improve its exploration and exploitation capability. In the comparative experiment of PMSM speed control, ADESA fractional-order PID was contrasted with conventional PID and other intelligent optimization algorithms. The results indicate that the PMSM control utilizing fractional-order PID through ADESA demonstrated minimal overshoot, the fastest response time, and superior anti-disturbance capabilities compared to PID and other intelligent optimization algorithms. This significantly enhanced the control performance of the permanent magnet synchronous motor.

Design and Implementation of Improved Gate Driver Circuit for Sensorless Permanent Magnet Synchronous Motor Control

Reliable motor control is important for electric vehicle applications. The control process requires accurate measurements of the current and rotor position information to establish correct motor control design, particularly in sensorless permanent magnet synchronous motor control systems. Practical issues regarding the motor control circuit, such as the effects of parasitic element behavior on the switching components in the insulated gate bipolar transistor-driven inverter, were discussed in this study. It analyzed the effects of parasitic elements that can cause the ringing of switching losses and affect the spike of the signal in the motor current, which must be avoided in the implementation of motor control. The gate driver circuit topology was improved to reduce this effect in motor control devices. The proposed gate driver circuit design with the ringing suppression circuit configuration achieved good performance by keeping the signal spike at less than 10% in the motor current. Furthermore, a signal spike or noise was not observed in the estimation results of rotor position when using current information as the parameter control process. Both conditions were verified by experiments on the designed motor control devices. Under these conditions, signal precision can be achieved in motor control.

Continuous power imbalance assessment from multi-area economic dispatch models

To be able to efficiently maintain a continuous balance between supply and demand in power systems with high shares of variable renewable energy (VRE) sources, a variety of studies related to the topic are needed. A fundamental input parameter for such studies is an assessment of the power system’s physical needs for balancing power, in form of power imbalances. This article presents a new model for simulating physical power imbalances with a 1-minute time resolution based on multi-area economic dispatch simulations. Compared to existing models with the same purpose, the new model includes the combination of simulating power imbalances with 1-minute time resolution, simulating forecast uncertainty, simulating the continuous behaviour of all power system components and simulating the transmission for netting of power imbalances between balancing areas. By applying the model to a case study of the Nordic synchronous power system in year 2045, the impact of including these features in the model is highlighted. Case study results also show that the size and pattern of power imbalances much depends on the characteristics of a balancing area, in terms of electricity demand, available generation technologies and interconnections to other balancing areas.

Development of prototype system for quantum two-way clock synchronization

In this Letter, we report a prototype system that realizes the complete functionality for quantum two-way time transfer, comparison, and synchronization between two integrated terminals. The synchronization performance was tested over a 50-km spooled fiber link. With the common frequency reference, the time deviation was measured as 0.45 ps at an averaging time of 104 s, which is limited by the system's hardware and determines the minimum achievable synchronization stability. By employing an open-loop fiber-optic microwave frequency transfer in combination with the technique of dynamically identifying and steering the time offset between the terminals, a synchronization stability of 1.26 ps at 104 s was achieved. Further utilizing the grey prediction model to correct the time offset data, the synchronization stability was significantly improved to 0.69 ps at 104 s, showing its potential to enhance the synchronization performance. This report marks the development of a utility quantum two-way clock synchronization system. The ongoing exploration of advanced time-offset adjustment strategies to attain synchronization stability significantly below 1 ps is poised to yield invaluable benefits for future applications.

Performance Simulation Analysis of Synchronous Hydraulic System for Variable-Diameter Threshing Drum

To meet the requirement that the traditional combine harvester can adjust the threshing gap in real time according to different working conditions, a hydraulic driven variable-diameter threshing drum and a synchronous hydraulic system were developed in the early stage. However, the performance of synchronous hydraulic system has not been studied in detail. Therefore, AMESim software was used to simulate and analyze the synchronous hydraulic system to verify its feasibility in this study. The results showed that the synchronization error of synchronous hydraulic system was less than 0.02 mm. When the hydraulic system was self-locking, the position fluctuation of the piston rod of hydraulic cylinder was less than 0.06 mm. When the hydraulic cylinder did not work, the logic valve effectively ensured that the hydraulic oil could directly return to the oil tank, resulting in the minimum energy loss of the system. The flow control valve could regulate the flow rate of the hydraulic system, causing the adjusting speed of the drum diameter can be adjusted. The hydraulic system pressure was determined to be 8 Mpa.

An Online Adaptive Damping Controller for Converter-Interfaced Generation

The increasing integration of converter-interfaced generation within large-scale synchronous power systems is presenting both new challenges and opportunities in how we operate these dynamical networks. One of these challenges is designing and parameterizing the digital control loops that dictate the dynamical behavior of these fast-acting resources. Improperly tuned gains, or unexpected controller couplings through the network, can lead to poorly damped oscillations during disturbance conditions and/or decrease the system stability margin. Within this work, we present an approach for adaptively tuning a damping controller to improve the dynamic response of converter-interfaced generation, based only on local measurements. We show that, with low-amplitude probing, we can identify a subset set of observable system modes. We then propose a linear MISO state-feedback controller to improve the damping ratio and stability margin of the system. We show the effectiveness of the proposed controller through both eigenvalue analysis and time-domain simulations. We first demonstrate the proposed approach on a simple 3-bus system followed by a larger test case, the IEEE 14 bus system, with multiple devices simultaneously probing the network.

Fault Diagnosis Method of Inter-Turn Short Circuit of Permanent Magnet Synchronous Motor Based on Third Harmonic

In order to realize the effective diagnosis of turn to turn short circuit fault of permanent magnet synchronous motor, a method of turn to turn short circuit fault diagnosis of permanent magnet synchronous motor based on third harmonic is proposed in this paper. Establish the system frequency oscillation analysis model of permanent magnet synchronous motor under the condition of turn to turn short circuit, collect the turn to turn harmonic of permanent magnet synchronous motor, then realize the third harmonic detection of permanent magnet synchronous motor under turn to turn short circuit fault, and detect the inertia of permanent magnet synchronous motor system. Based on the transient energy analysis and fault feature extraction, the turn to turn short circuit fault of permanent magnet synchronous motor is diagnosed. The test results show that this method has high reliability and good detection performance, and can improve the output stability and condition monitoring ability of permanent magnet synchronous motor.

FPGA-Based Real-Time Synchronous Parallel System for Underwater Acoustic Positioning and Navigation

With the development of autonomous underwater vehicles, the research of underwater acoustic positioning and navigation technology is becoming increasingly important. However, most underwater positioning systems use the traditional acoustic response synchronization method, which leads to insufficient positioning real-time performance and refresh rate. To solve this problem, this paper proposes a real-time global synchronization mechanism with high-precision atomic clocks, which can realize one positioning through one-way propagation, so that the positioning efficiency is at least doubled. To further improve the positioning accuracy, an M-sequence-based phase offset modulation method is proposed to facilitate beacon identification. Consequently, a normalized signal matching capture algorithm against Doppler effect is designed, and the positioning solution is fused with the real-time sound ray bending compensation mechanism. Based on the above content, we developed an FPGA-based real-time synchronous parallel underwater positioning and navigation (RSPUPN) system, which uses FPGA+MCU architecture to accelerate signal processing operations in a low-power and parallel way. The test results in the South China Sea show that the operating range of the system can reach 8 km, the positioning refresh rate can reach 0.2 Hz, and the relative average position error is 0.25%, confirming the effectiveness of the designed system in industrial applications.