The software-based computer numerical control（CNC） system includes three types of tasks： periodic real-time tasks, aperiodic real-time tasks, and non-real-time tasks. The tasks are characterized by concurrency, hyb...The software-based computer numerical control（CNC） system includes three types of tasks： periodic real-time tasks, aperiodic real-time tasks, and non-real-time tasks. The tasks are characterized by concurrency, hybridization, and correlation, which make system implementation difficult. The conventional scheduling algorithm can not meet the demands of system implementation in the software-based CNC system completely. The uncertainty factors when running real-time tasks affect control performance by degrading manufacturing accuracy as a result of system resource and processor use restrictions. To address the technical difficulty of embedded system implementation, a novel fuzzy feedback scheduling algorithm based on output jitter of key real-time tasks for a software-based CNC system is proposed. Time characteristics, such as sampling jitter, input-output jitter, and non-schedulability are discussed, followed by quantification through simulations of the impact of time characteristics on manufacturing accuracy. On the basis of this research, the scheduler architecture is designed, and then the algorithm table is calculated. When the system resource changes, the key periodic real-time tasks meet their deadlines by means of dynamically adjusting the task period. The simulated results show that the machining precision rises by an order of magnitude for the proposed scheduler in resource-constrained software-based CNC systems. Moreover, unlike conventional feedback scheduling methods, the algorithm in this paper does not rely on the availability of task execution times and is easy to implement while incurring only a small overhead.展开更多
ERP mainly relates to business management software which consists of several modules that are important for the growth and survival of different types of businesses and organisations. The integration of related busine...ERP mainly relates to business management software which consists of several modules that are important for the growth and survival of different types of businesses and organisations. The integration of related business applications in an organisation can bring significant advantages to the business by enabling faster supply chain management. ERP implementation enables firms to adapt and configure information flows and integrate business processes in order to enhance business performance. System implementation has been reviewed with adequate literature to significantly support the importance of arithmetic and logical concepts and basic errors in programming including typographical errors in a programme, identification of syntax errors and programme output process errors. It has further discussed the variables declaration, significance of modularization and necessity of supporting accessories along with the usability of library files and the importance of the use of frameworks. Enhancement of coding formatting and significance of coding syntax were also critically reviewed with sufficient literature to identify the system implementation failures in the ERP development process.展开更多
The Orthogonal Frequency Division Multiplexing (OFDM) system is already used in commercial applications and is capable to deal with Intersymbolic Interference (ISI) caused by multipath channels. This system gained pop...The Orthogonal Frequency Division Multiplexing (OFDM) system is already used in commercial applications and is capable to deal with Intersymbolic Interference (ISI) caused by multipath channels. This system gained popularity after the application of the Fast Fourier Transform (FFT) and its inverse (IFFT) to modulate the signal in many subcarriers. This paper discusses implementation aspects of an OFDM system;such system is characterized by considering real constraints, including the memory consumption and the processing time. The OFDM modulator, channel samples and OFDM demodulator were implemented entirely in the DSP TMS320C6678 platform. As a proof-of-concept, a 256-QAM OFDM BER performance is compared with theoretical values. Moreover, the memory size is not demanding, consuming very few resources. It was observed a very high number of DSP clock cycles needed for the OFDM signal modulation, corresponding to more than 4 times the number used in demodulating the signal.展开更多
In this paper, the structure of a new chaotic bitwise dynamical system （CBDS） is described. Compared to our previous research work, it uses various random bitwise operations instead of only one. The chaotic behavior...In this paper, the structure of a new chaotic bitwise dynamical system （CBDS） is described. Compared to our previous research work, it uses various random bitwise operations instead of only one. The chaotic behavior of CBDS is mathemat- ically proven according to the Devaney＇s definition, and its statistical properties are verified both for uniformity and by a comprehensive, reputed and stringent battery of tests called TestU01. Furthermore, a systematic methodology developing the parallel computations is proposed for FPGA platform-based realization of this CBDS. Experiments finally validate the proposed systematic methodology.展开更多
In the paper, a novel four-wing hyper-chaotic system is proposed and analyzed. A rare dynamic phenomenon is found that this new system with one equilibrium generates a four-wing-hyper-chaotic attractor as parameter va...In the paper, a novel four-wing hyper-chaotic system is proposed and analyzed. A rare dynamic phenomenon is found that this new system with one equilibrium generates a four-wing-hyper-chaotic attractor as parameter varies. The system has rich and complex dynamical behaviors, and it is investigated in terms of Lyapunov exponents, bifurcation diagrams, Poincare maps, frequency spectrum, and numerical simulations. In addition, the theoretical analysis shows that the system undergoes a Hopf bifurcation as one parameter varies, which is illustrated by the numerical simulation. Finally, an analog circuit is designed to implement this hyper-chaotic system.展开更多
A simple three-dimensional （3D） autonomous chaotic system is extended to four-dimensions so as to generate richer nonlinear dynamics. The new system not only inherits the dynamical characteristics of its parental 3D...A simple three-dimensional （3D） autonomous chaotic system is extended to four-dimensions so as to generate richer nonlinear dynamics. The new system not only inherits the dynamical characteristics of its parental 3D system but also exhibits many new and complex dynamics, including assembled 1-scroll, 2-scroll and 4-scroll attractors, as well as hyperchaotic attractors, by simply tuning a single system parameter. Lyapunov exponents and bifurcation diagrams are obtained via numerical simulations to further justify the existences of chaos and hyperchaos. Finally, an electronic circuit is constructed to implement the system, with experimental and simulation results presented and compared for demonstration and verification.展开更多
In this paper, the optimal estimate method is systematically investigated for estimating the position and velocity vectors of a short range target in space with a multisensor system TR n (one transmitting sensor...In this paper, the optimal estimate method is systematically investigated for estimating the position and velocity vectors of a short range target in space with a multisensor system TR n (one transmitting sensor and n receiving sensors). A suboptimal and realizable signal processing scheme is provided. The performance of the suboptimal procedure is analyzed theoretically in detail, and analytical expressions are obtained for the covariance matrix of the estimator error. Simulation results verify the theoretical prediction, which demonstrates the system is able to accurately locate a short range target.展开更多
The traceability management system for pigs based on personal digital assistant （PDA） was constructed by software engineering method to provide the traceability management for pork safety. This traceability system i...The traceability management system for pigs based on personal digital assistant （PDA） was constructed by software engineering method to provide the traceability management for pork safety. This traceability system included information managements for pig breeding and pig quaran- tine inspection supervision. It also realized the record and supervision of pig information, feed usage, veterinary drug usage and quarantine inspec- tion. We mainly introduced the designs of systemic structure and functional structure of the traceability system and key techniques of system imple- mentation.展开更多
The large scale and complex manufacturing systems have a hierarchical structure where a system is composed several lines with some stations and each station also have several machines and so on. In such a hierarchical...The large scale and complex manufacturing systems have a hierarchical structure where a system is composed several lines with some stations and each station also have several machines and so on. In such a hierarchical structure, the controllers are geographically distributed according to their physical structure. So it is desirable to realize the hierarchical and distributed control. In this paper, a methodology is presented using Petri nets for hierarchical and distributed control. The Petri net representation of discrete event manufacturing processes is decomposed and distributed into the machine controllers, which are coordinated through communication between the coordinator and machine controllers so that the decomposed transitions fire at the same time. Implementation of a hierarchical and distributed control system is described for an example robotic manufacturing system. The demonstrations show that the proposed system can be used as an effective tool for consistent modeling and control of large and complex manufacturing systems.展开更多
[目的/意义]AI4S(AI for Science)作为人工智能(Artificial Intelligence,AI)与科学研究深度融合的新兴形态,引发了科研范式的深刻变革,通过AI技术加速科学发现,推动科学研究从传统的经验、直觉驱动向数据与AI共同驱动转变,已在众多科...[目的/意义]AI4S(AI for Science)作为人工智能(Artificial Intelligence,AI)与科学研究深度融合的新兴形态,引发了科研范式的深刻变革,通过AI技术加速科学发现,推动科学研究从传统的经验、直觉驱动向数据与AI共同驱动转变,已在众多科学领域实现了创新突破,也为农业科研转型带来新的机遇。[进展]本文梳理并分析了AI4S发展现状及其对农业科研产生的影响,研究发现近年来AI4S已取得显著进展,国内外积极布局相关前沿领域并出台系列政策以抢占新一轮科技战略制高点,且在多个学科领域得到了广泛应用。在农业科研领域,AI在加速多学科交叉融合、促进科研效率提升、助力复杂问题突破、驱动科研范式变革和升级科研基础设施五个方面发挥了重要作用。[结论/展望]面向农业科研新需求、核心领域与研究过程,提出了农业智能科研(A IforAgri-cultural Science,AI4AS)的概念及体系关键要素,涵盖大科学基础设施、大数据资源、大模型算法和大协同平台等部分。最后,针对数据资源、模型能力、科研生态,以及人才培养等挑战,从顶层设计规划、关键技术体系、协同创新体系、学科体系建设、复合人才引育等角度,提出打造面向AI4S发展的农业科研新体系的实现路径与具体建议。展开更多
基金supported by National Natural Science Foundation of China(Grant No.50875090,Grant No.50905063)National Hi-tech Research and Development Program of China(863 Program,Grant No.2009AA4Z111)China Postdoctoral Science Foundation (Grant No.20090460769)
文摘The software-based computer numerical control（CNC） system includes three types of tasks： periodic real-time tasks, aperiodic real-time tasks, and non-real-time tasks. The tasks are characterized by concurrency, hybridization, and correlation, which make system implementation difficult. The conventional scheduling algorithm can not meet the demands of system implementation in the software-based CNC system completely. The uncertainty factors when running real-time tasks affect control performance by degrading manufacturing accuracy as a result of system resource and processor use restrictions. To address the technical difficulty of embedded system implementation, a novel fuzzy feedback scheduling algorithm based on output jitter of key real-time tasks for a software-based CNC system is proposed. Time characteristics, such as sampling jitter, input-output jitter, and non-schedulability are discussed, followed by quantification through simulations of the impact of time characteristics on manufacturing accuracy. On the basis of this research, the scheduler architecture is designed, and then the algorithm table is calculated. When the system resource changes, the key periodic real-time tasks meet their deadlines by means of dynamically adjusting the task period. The simulated results show that the machining precision rises by an order of magnitude for the proposed scheduler in resource-constrained software-based CNC systems. Moreover, unlike conventional feedback scheduling methods, the algorithm in this paper does not rely on the availability of task execution times and is easy to implement while incurring only a small overhead.
文摘ERP mainly relates to business management software which consists of several modules that are important for the growth and survival of different types of businesses and organisations. The integration of related business applications in an organisation can bring significant advantages to the business by enabling faster supply chain management. ERP implementation enables firms to adapt and configure information flows and integrate business processes in order to enhance business performance. System implementation has been reviewed with adequate literature to significantly support the importance of arithmetic and logical concepts and basic errors in programming including typographical errors in a programme, identification of syntax errors and programme output process errors. It has further discussed the variables declaration, significance of modularization and necessity of supporting accessories along with the usability of library files and the importance of the use of frameworks. Enhancement of coding formatting and significance of coding syntax were also critically reviewed with sufficient literature to identify the system implementation failures in the ERP development process.
文摘The Orthogonal Frequency Division Multiplexing (OFDM) system is already used in commercial applications and is capable to deal with Intersymbolic Interference (ISI) caused by multipath channels. This system gained popularity after the application of the Fast Fourier Transform (FFT) and its inverse (IFFT) to modulate the signal in many subcarriers. This paper discusses implementation aspects of an OFDM system;such system is characterized by considering real constraints, including the memory consumption and the processing time. The OFDM modulator, channel samples and OFDM demodulator were implemented entirely in the DSP TMS320C6678 platform. As a proof-of-concept, a 256-QAM OFDM BER performance is compared with theoretical values. Moreover, the memory size is not demanding, consuming very few resources. It was observed a very high number of DSP clock cycles needed for the OFDM signal modulation, corresponding to more than 4 times the number used in demodulating the signal.
基金Project supported by China Postdoctoral Science Foundation(Grant No.2014M552175)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Chinese Education Ministry+1 种基金the National Natural Science Foundation of China(Grant No.61172023)the Specialized Research Foundation of Doctoral Subjects of Chinese Education Ministry(Grant No.20114420110003)
文摘In this paper, the structure of a new chaotic bitwise dynamical system （CBDS） is described. Compared to our previous research work, it uses various random bitwise operations instead of only one. The chaotic behavior of CBDS is mathemat- ically proven according to the Devaney＇s definition, and its statistical properties are verified both for uniformity and by a comprehensive, reputed and stringent battery of tests called TestU01. Furthermore, a systematic methodology developing the parallel computations is proposed for FPGA platform-based realization of this CBDS. Experiments finally validate the proposed systematic methodology.
基金supported by the National Natural Science Foundation of China(Grant Nos.10772135 and 60874028)the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.11202148)+2 种基金the Incentive Funding of the National Research Foundation of South Africa(GrantNo.IFR2009090800049)the Eskom Tertiary Education Support Programme of South Africathe Research Foundation of Tianjin University of Science and Technology
文摘In the paper, a novel four-wing hyper-chaotic system is proposed and analyzed. A rare dynamic phenomenon is found that this new system with one equilibrium generates a four-wing-hyper-chaotic attractor as parameter varies. The system has rich and complex dynamical behaviors, and it is investigated in terms of Lyapunov exponents, bifurcation diagrams, Poincare maps, frequency spectrum, and numerical simulations. In addition, the theoretical analysis shows that the system undergoes a Hopf bifurcation as one parameter varies, which is illustrated by the numerical simulation. Finally, an analog circuit is designed to implement this hyper-chaotic system.
基金Supported by National Naturai Science Foundation of China （61273104, 61021002, 61104097）, and Projects of Major Interna-tional （Regional） Joint Research Program National Natural Science Foundation of China （61120106010）
文摘A simple three-dimensional （3D） autonomous chaotic system is extended to four-dimensions so as to generate richer nonlinear dynamics. The new system not only inherits the dynamical characteristics of its parental 3D system but also exhibits many new and complex dynamics, including assembled 1-scroll, 2-scroll and 4-scroll attractors, as well as hyperchaotic attractors, by simply tuning a single system parameter. Lyapunov exponents and bifurcation diagrams are obtained via numerical simulations to further justify the existences of chaos and hyperchaos. Finally, an electronic circuit is constructed to implement the system, with experimental and simulation results presented and compared for demonstration and verification.
文摘In this paper, the optimal estimate method is systematically investigated for estimating the position and velocity vectors of a short range target in space with a multisensor system TR n (one transmitting sensor and n receiving sensors). A suboptimal and realizable signal processing scheme is provided. The performance of the suboptimal procedure is analyzed theoretically in detail, and analytical expressions are obtained for the covariance matrix of the estimator error. Simulation results verify the theoretical prediction, which demonstrates the system is able to accurately locate a short range target.
基金supported by the Agricultural Science and Technology Innovation Project of Yunnan Province(2008LA020)sub-topic of National Key Technology R&D Program(2006BAD14B04)
文摘The traceability management system for pigs based on personal digital assistant （PDA） was constructed by software engineering method to provide the traceability management for pork safety. This traceability system included information managements for pig breeding and pig quaran- tine inspection supervision. It also realized the record and supervision of pig information, feed usage, veterinary drug usage and quarantine inspec- tion. We mainly introduced the designs of systemic structure and functional structure of the traceability system and key techniques of system imple- mentation.
文摘The large scale and complex manufacturing systems have a hierarchical structure where a system is composed several lines with some stations and each station also have several machines and so on. In such a hierarchical structure, the controllers are geographically distributed according to their physical structure. So it is desirable to realize the hierarchical and distributed control. In this paper, a methodology is presented using Petri nets for hierarchical and distributed control. The Petri net representation of discrete event manufacturing processes is decomposed and distributed into the machine controllers, which are coordinated through communication between the coordinator and machine controllers so that the decomposed transitions fire at the same time. Implementation of a hierarchical and distributed control system is described for an example robotic manufacturing system. The demonstrations show that the proposed system can be used as an effective tool for consistent modeling and control of large and complex manufacturing systems.
