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Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Power Generation Technology is the property of Power Generation Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chongqing University of Posts & Telecommunications (Natural Science Edition) is the property of Chongqing University of Posts & Telecommunications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Guangdong University of Technology is the property of Journal of Guangdong University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To address the problems of poor interactivity and reliance on experience in decision-making during the aerobic fermentation process of cow dung, a fermentation process monitoring system based on digital twin technology was designed. Firstly, a digital twin virtual model of the fermentation chamber was constructed using the Unity engine, and the scene environment and virtual interface were designed and built. Secondly, the IoT gateway and database were designed for transmitting and storing twin data. Finally, a simulation platform was built to conduct time-series synchronization and collision detection experiments on the digital twin system. The experimental results show that the designed digital twin monitoring system virtual model of the fermentation silo has high synchronization with the physical object, which can achieve the virtual and real synchronization, and verifies the feasibility of the system. [ABSTRACT FROM AUTHOR]

The application of new generation information technology in ITMA ASIA+CITME 2022 was discussed. From aspects of storage logistics digital twin, precision management of raw cotton, single spindle monitoring, remote equipment operation and maintenance, application scenarios and solutions of new generation information technology were reviewed. It was pointed out that the research and development direction of textile machinery enterprises mainly focused on the digitalization, automation, intelligent production and quality control of high-efficiency, energy-saving and high value-added textiles. The new generation information technology had made the digital upgrading of the industry faster and more efficient, the overall level of intelligence in textile production was significantly improved. The new ecology of textile industry based on industrial Internet was accelerating. It is considered the integration and application of new generation information technology with the textile industry has promoted collaborative innovation in product research and development, manufacturing and service, which helping enterprises achieve strategic goals of improving quality, efficiency and high-quality development. [ABSTRACT FROM AUTHOR]

[Objective] As a fundamental course in engineering colleges, the control course is essential in electrical, mechanical, and automation majors. However, the teaching process is not easy. Aiming at the challenges of abstract knowledge and lack of visualization display in control courses, we built a virtual control engineering laboratory with a digital twin as the featured board based on the digital twin theory. [Methods] Through the digital twin experimental module, the simulation animation is synchronized with the kinematics of the solid model, and the hidden control theory is shown. Herein, LabVIEW is employed as the primary program platform to build a virtual laboratory applicable to the teaching of mechanical control engineering; the construction of the digital twin experimental module is achieved using SolidWorks software, STM32 microcontroller, and distance measuring laser module. Through the rich combination of controls, the time and frequency domain models of the adjustable control system are built in LabVIEW, the time and frequency domain characteristic curves are presented, and the modules of time domain, frequency domain, and stability analyses are written. To create the digital twin experimental bench, SolidWorks is used to establish three-dimensional models of the test bench, mass blocks, and springs; further, the three-dimensional model of the experimental bench is imported into the LabVIEW program, and the physical experimental bench was fabricated using metal machining processes. To achieve consistency between the virtual model and the physical motion state, the sensor needs to collect the motion state of the mass block in real time. To avoid the control system from external interference, we adopt a displacement laser sensor with a high sampling frequency to collect the real-time motion of the mass block. Based on the serial communication protocol, the STM 32 microcontroller serves as the slave computer to collect the data uploaded by the sensor and transfer it to the computer for subsequent processing. The data acquisition control driver available in LabVIEW acquires the amount of information from the serial port, processes it, and transfers it to the virtual model as a data stream. The position of the virtual model is updated at a high frequency in the program, achieving correspondence between the digital mirror and the movement of the physical entity, in addition to the digital twin synchronization. [Results] The developed virtual laboratory of mechanical control engineering achieved the following functions: showing the time domain characteristic, frequency domain characteristic curve, and Nyquist diagram of the control system; solving the gain and phase margins to solve the zero and pole; reproducing the two-system stability discrimination methods, i.e., Nyquist stability and stability margin criteria; showing the trajectory of the system pole with change in parameters; constructing different simulation models to realize the digital twin experimental module. [Conclusions] Through these functions, the organic combination of teaching, simulation, and digital twin is achieved, which boosts the experimental teaching link of the control course to a certain degree and offers guidance for the cultivation of innovative talents and the construction of virtual simulation laboratories. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] The rapid development of the intelligent transportation industry brings new opportunities and challenges for talent cultivation. The traditional cultivation system and teaching platforms for transportation majors face the following problems: 1) The cultivation modes of talents are not suitable for the rapid development of the industry. 2) The teaching methods are not coordinated with the development of industrial technologies. 3) The construction of a practical teaching platform is not synchronized with industrial development. 4) There is no sustainable and effective cooperation mechanism in the integration of industry and education. To solve the above problems, a teaching reform method based on the digital twin is proposed in this paper. [Methods] First, this paper analyzed the demand for transportation innovation talents and the significance of technological innovation capabilities, interdisciplinary comprehensive capabilities, and industry foresight capabilities. Meanwhile, a double-closed-loop innovative talent cultivation system of the integration of industry and education was established. One closed loop was theoretical teaching and professional skills practice, and the other closed loop was industrial demand and school supply. Second, a transportation digital twin method was proposed based on the five-dimensional model of the digital twin. The five dimensions of physical space, cyberspace, service system, digital twin data, and connection were deeply integrated with traffic scenarios. Based on the transportation digital twin method, this paper combined hardware (e.g., intelligent roadside devices, driving simulators, and miniature intelligent vehicles) with software (e.g., PreScan, Matlab, and PyCharm) to build the transportation digital twin experimental platform. The platform comprised three parts: the real traffic road, the cyberspace, and the semiphysical traffic simulation scene. Using this platform, real field tests can be replaced by digital twin experiments in the laboratory. Third, a typical experimental example of autonomous driving was selected to demonstrate the operating steps, including data collection and preprocessing, data conversion and traffic scenario construction, and autonomous driving algorithm development. Finally, six indexes were selected to evaluate the transportation digital twin teaching reform method, including learning attitude, cognition of majors, practical participation, course satisfaction, academic performance, and science and technology competition. [Results] The final evaluation results showed the following: 1) The proposed method can meet the learning needs of students, allow students to have a deep understanding of the practical applications of transportation professional courses, and improve their learning attitudes and cognition of majors. 2) Cyber space can provide students with repeated practice opportunities, effectively stimulating their enthusiasm for innovation and creativity, thereby improving their practical participation and course satisfaction. 3) There is a positive effect in promoting students' class performance, experimental results, and exam results, among others. This plays an important role in science and technology competitions. [Conclusions] The proposed teaching reform method based on the digital twin solved the problems existing in traditional transportation talent training systems and teaching platforms, which is of great significance for the cultivation of innovative talents of transportation majors. [ABSTRACT FROM AUTHOR]

Digital twin construction has become a hot spot in architecture by combining information and construction technologies. It realizes the interaction and integration of the physical construction and the digital model and promotes the upgrade of the building industry. This paper summarizes the basic concept, technical connotation, and advantages of digital twin construction, analyzes its current status and development trends in global academic research, and introduces digital twin construction methods and critical technologies through representative cases. Finally, through two construction practices carried out by the author's team in recent years, it illustrates the operational mechanism and the workflow of real-time optimization of digital twin construction. [ABSTRACT FROM AUTHOR]

A segmented estimation method of roughness based on the variation of hydraulic radius and estimation accuracy is proposed in order to realize the real- time and high- fidelity roughness estimation of hydrodynamic digital twin (DT) models. This method considers the spatial variability of the roughness value in the longitudinal direction of canals. Based on canal segmentation, two different estimation frameworks, the independent estimation method and joint estimation method, are proposed. The ensemble Kalman filter algorithm is applied to estimate the roughness of each canal segment online based on the limited observed water levels. The results show that the two estimation methods can improve the accuracy of the model by 20% —50% . In addition, the independent estimation method is suitable for a complex canal system with a small error accumulation, while the joint estimation method is suitable for simple canals with unavailable observations. The proposed method can be used for parameter estimation and variable updating of hydrodynamic DT models, and provide a reference for the construction of DT water networks. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the complex and changeable flight operation environment, a dynamic prediction model of flight chain delay based on digital twin is proposed to improve the accuracy and adaptability of the traditional prediction methods. The model is constructed based on the digital twin flight chain system. Through the model, the unit-level delay prediction is accomplished by the multi-channel feature modeling method under the sliding windows, and the parameter optimization is completed by a hybrid optimization strategy. Moreover, the whole chain’s delays are analyzed and corrected with the help of the twin data-driven strategy. Flight data in China are used to conduct the study. The mean absolute error (MAE) of flight delay prediction is 11.79 min, which is lower than those of other baseline models or static models, and the forecast error of subsequent flight delay can be reduced by 6.44% after twin data-driven analysis is implemented. The results show that the model is beneficial for the digital twin system to realize the virtual reality interaction, and has excellent prediction accuracy and adaptability. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

After completing the technical integration of beneficiation equipment, processes, automation, and IT, the Sanshandao gold mine has significantly improved the reliability of its beneficiation equipment and processes, and achieved a higher level of intelligence in gold beneficiation through the upgrades in data acquisition platforms, intelligent operation of the beneficiation plant, and VR beneficocetoon plant. The mine has achieved stable and optimized production processes, leading to reduced manpower and increased efficiency. This has resulted in improved technical indicators and economic benefits, establishing it as one of the world’s advanced gold beneficiation plants. [ABSTRACT FROM AUTHOR]

Copyright of Pearl River is the property of Pearl River Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zhejiang Electric Power is the property of Zhejiang Electric Power Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on digital twin, a real-time assembly man-hours workshop scheduling model was proposed, considering the uncertainty of assembly man-hours in the process of product customization and frequent dynamic disturbances in the assembly workshop. The overall architecture of assembly workshop scheduling based on digital twin was constructed. Radio frequency identification (RFID) technology was used to collect real-time working hours data of physical assembly workshops, and the real-time assembly working hours were processed by using the improved Rete algorithm. A mathematical model of assembly workshop scheduling based on real-time assembly man-hours was established, and an improved artificial fish swarm-taboo algorithm was used to solve the model, so as to realize the scheduling optimization of the real-time assembly man-hours workshop. The empirical result shows that the model algorithm has certain feasibility and superiority in real-time assembly man-hours workshop scheduling. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Smart Rail Transit is the property of Smart Rail Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Positioning navigation and timing (PNT) is the nation's critical infrastructure. At present, China has established the relatively complete ground-based augmentation systems, satellite-based augmentation systems and low earth orbit(LEO) satellite-based augmentation system for comprehensive PNT. Although indoor positioning on a contemporary smartphone is booming, including Wi-Fi, bluetooth, magnetic field fingerprinting, and so on, these existing methods still cannot provide high quality PNT services for the whole area, such as underground, indoor space, and underwater. Recently, the key technologies of real three-dimensional model and digital twin model received more and more attention. The information of geographic scene presents unrecalled opportunities to improve the robust availability, continuity, high accuracy and reliability of comprehensive PNT system. First, we introduce the state-of-the-art of related studies of scene-based augmentation systems, including scene-based PNT systems augmentation. Second, we summarize the challenges and present the definition and basic concept of the scene-based augmentation systems for comprehensive PNT. Next, the system architecture, construction units and hierarchical service mechanism of scene-based augmentation systems is proposed. Finally, we forecast the development trend of scene-based augmentation systems for comprehensive PNT. The China comprehensive PNT system should be BeiDou-centered and include ground-based augmentation systems, satellite-based augmentation systems (SBAS), LEO SBAS and scene-based augmentation systems for comprehensive PNT as auxiliary augmentation systems. It has the ability to provide intelligent PNT services in whole area. [ABSTRACT FROM AUTHOR]

The digital twin city seeks to restore virtually the geographic scene that is close to reality and provide the audience an immersive experience. Three dimensional (3D) real urban scene is one of the key technologies to achieve the goal. Nowadays, the combination of geographic information system and game engine becomes an industrial trend and provides new opportunities for 3D real urban scene. Oblique photogrammetric data, as being a fundamental data source for 3D urban modeling, is able to represent large-scale and high-precision scene. The game engine plays an excellent role in offering realistic effects and post-production systems that are greatly useful for geospatial data visualization. However, the diversity of specifications and formats of oblique photogrammetric data has caused many different data loading and transformation methods, resulting in a problem to be solved in 3D real urban scene. Methods: This paper aims to propose a data transformation approach from oblique photogrammetric data to rendering resources in game engine. To stress, the proposed approach can allow us to load instantly massive amount of oblique photogrammetric data in Unreal Engine, which is one of the most popular game engines. We further compared oblique photogrammetric data with rendering resources in game engine and discussed the significance of such a data transformation. The approach reorganizes the original structure of the data by parsing data into a tree structure that better suits transformation purposes. Also, the proposed approach transforms respectively the geometry and texture data when iterating tree nodes, as well as considers the essential physical properties of rendering assets. All these features are combined into a package data format. Results: In the case study of Futian district, Shenzhen, the results show that the proposed approach successfully converts oblique photogrammetric data to rendering resources in Unreal Engine 4. In the transformation process, the geometrical structure and collision properties of triangular mesh are guaranteed, and color, bump and other visual elements of original data are kept in materials. The rendering resources are loaded to simulate the real urban scenarios at different time periods of a day in Unreal Engine 4. Conclusions: This paper devises a novel approach which can convert the oblique photogrammetric data into rendering resource for a game engine to load and render, and meantime maintain the consistency of data's geometry and texture. For its scalability, it also supports parallel processing of large-scale data transformation when data is organized in the same directory. The proposed approach may be of great theoretical and practical value for other related 3D model data transformation problems. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of East China University of Science & Technology is the property of Journal of East China University of Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ordnance Industry Automation is the property of Editorial Board for Ordnance Industry Automation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As Software Defined Network（SDN） is increasingly widely used in various scenarios, a new challenge for SDN to support dynamic requirements of various applications begin to emerge. Digital Twin（DT） can enhance the capabilities of SDN in aspects of real-time analysis, deduction, and network control, and consequently satisfy the dynamic requirements of various applications. Whereas, current DT constructing schemes for SDN usually suffer from the challenges of strict delay constraint, heavy computing overhead, and low cooperating efficiency. To address the above issue, this paper proposes a novel Variable Granularity-Digital Twin（VGDT） according to the application requirement and available computing resource. Based on the distribution characteristic of the computing resource in the network, VGDT builds a cooperatively optimizing model to ensure the delay and effectiveness of the DT for SDN. Then, this paper proposes a hybrid coding genetic algorithm to solve this model, which can achieve the best granularity and the DT placement policy. The simulation results show the performance of VGDT. Compared with current DT, VGDT has higher integrity and validity of digital twin model under limited computing resource. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)