One of the most important features of modern minor satellites is to realize autonomous moving. The performance of the satellite autonomous computer operating system acting as the control center is utmost important. Th...One of the most important features of modern minor satellites is to realize autonomous moving. The performance of the satellite autonomous computer operating system acting as the control center is utmost important. The recent trend in operating system development is adopting microkernel architecture which holds such advantages as microminiaturization, modularity, portability and extendibility. The performance of I/O subsystem is currently receiving considerable research attention. Object-orientation offers an approach to application development in which software system can be constructed by composing and refining the pre-designed plug-compatible software components.It also starts with some basic notions fairly well accepted in computer science, namely encapsulation and reuse. In this paper, a new object-oriented real-time I/O subsystem model has been designed.In this model, the traditional I/O subsystem framework is discarded and a stream mechanism based on the object-oriented concept is introduced. In addition, the I/O requests are classified according to their time emergency to obtain real-time performance. So, this model meets such satelliteperformance requirements as reliability, flexibility, portability and real-time performance.展开更多
To enhance the accuracy of intuitionistic fuzzy time series forecasting model, this paper analyses the influence of universe of discourse partition and compares with relevant literature. Traditional models usually par...To enhance the accuracy of intuitionistic fuzzy time series forecasting model, this paper analyses the influence of universe of discourse partition and compares with relevant literature. Traditional models usually partition the global universe of discourse, which is not appropriate for all objectives. For example, the universe of the secular trend model is continuously variational. In addition, most forecasting methods rely on prior information, i.e., fuzzy relationship groups (FRG). Numerous relationship groups lead to the explosive growth of relationship library in a linear model and increase the computational complexity. To overcome problems above and ascertain an appropriate order, an intuitionistic fuzzy time series forecasting model based on order decision and adaptive partition algorithm is proposed. By forecasting the vector operator matrix, the proposed model can adjust partitions and intervals adaptively. The proposed model is tested on student enrollments of Alabama dataset, typical seasonal dataset Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) and a secular trend dataset of total retail sales for social consumer goods in China. Experimental results illustrate the validity and applicability of the proposed method for different patterns of dataset.展开更多
A novel reconfigurable hardware system which uses both muhi-DSP and FPGA to attain high performance and real-time image processing are presented. The system structure and working principle of mainly processing multi-B...A novel reconfigurable hardware system which uses both muhi-DSP and FPGA to attain high performance and real-time image processing are presented. The system structure and working principle of mainly processing multi-BSP board, extended multi-DSP board are analysed. The outstanding advantage is that the communication among different board components of this system is supported by high speed link ports ＆ serial ports for increasing the system performance and computational power. Then the implementation of embedded real-time operating systems （RTOS） by us is discussed in detail. In this system, we adopt two kinds of parallel structures controlled by RTOS for parallel processing of algorithms. The experimental results show that exploitive period of the system is short, and maintenance convenient. Thus it is suitable for real-time image processing and can get satisfactory effect of image recognition.展开更多
In this paper,a novel train positioning method considering satellite raw observation data was proposed,which aims to promote train positioning performance from an innovative perspective of the train satellite-based po...In this paper,a novel train positioning method considering satellite raw observation data was proposed,which aims to promote train positioning performance from an innovative perspective of the train satellite-based positioning error sources.The method focused on overcoming the abnormal observations in satellite observation data caused by railway environment rather than the positioning results.Specifically,the relative positioning experimental platform was built and the zero-baseline method was firstly employed to evaluate the carrier phase data quality,and then,GNSS combined observation models were adopted to construct the detection values,which were applied to judge abnormal-data through the dual-frequency observations.Further,ambiguity fixing optimization was investigated based on observation data selection in partly-blocked environments.The results show that the proposed method can effectively detect and address abnormal observations and improve positioning stability.Cycle slips and gross errors can be detected and identified based on dual-frequency global navigation satellite system data.After adopting the data selection strategy,the ambiguity fixing percentage was improved by 29.2%,and the standard deviation in the East,North,and Up components was enhanced by 12.7%,7.4%,and 12.5%,respectively.The proposed method can provide references for train positioning performance optimization in railway environments from the perspective of positioning error sources.展开更多
针对大规模农田的粮食抢收工作,由于抢收约束时间的限制,导致可能无法在规定时间内完成所有粮食的收割任务,此时则会出现粮食损失值。构建以粮食损失值最小化为目标的农机跨区紧急调配模型,提出基于两阶段的农机紧急调配算法(Agricultur...针对大规模农田的粮食抢收工作,由于抢收约束时间的限制,导致可能无法在规定时间内完成所有粮食的收割任务,此时则会出现粮食损失值。构建以粮食损失值最小化为目标的农机跨区紧急调配模型,提出基于两阶段的农机紧急调配算法(Agricultural Machinery Emergency Algorithm based on Two Stages,TSEA)。首先按照基于距离的分区策略对大规模农田进行分区,接着采用改进的遗传算法分别对各农田分区进行农机紧急作业调配。为验证算法的有效性,主要从紧急任务的粮食损失值、算法运行时间等方面将TSEA算法与GA、SA算法进行比较,试验结果表明,TSEA算法得到的紧急调度方案优于其他两种算法。为验证本文分区策略的有效性,分别采用TSEA算法和不分区的紧急调配算法从粮食损失值、算法运行时间等方面进行比较,验证分区策略的有效性。多组试验结果表明该文提出的策略和算法对于解决大规模农田的农机跨区紧急调配问题更有效,可为农机管理部门提供解决方案。展开更多
文摘One of the most important features of modern minor satellites is to realize autonomous moving. The performance of the satellite autonomous computer operating system acting as the control center is utmost important. The recent trend in operating system development is adopting microkernel architecture which holds such advantages as microminiaturization, modularity, portability and extendibility. The performance of I/O subsystem is currently receiving considerable research attention. Object-orientation offers an approach to application development in which software system can be constructed by composing and refining the pre-designed plug-compatible software components.It also starts with some basic notions fairly well accepted in computer science, namely encapsulation and reuse. In this paper, a new object-oriented real-time I/O subsystem model has been designed.In this model, the traditional I/O subsystem framework is discarded and a stream mechanism based on the object-oriented concept is introduced. In addition, the I/O requests are classified according to their time emergency to obtain real-time performance. So, this model meets such satelliteperformance requirements as reliability, flexibility, portability and real-time performance.
基金supported by the National Natural Science Foundation of China(61309022)
文摘To enhance the accuracy of intuitionistic fuzzy time series forecasting model, this paper analyses the influence of universe of discourse partition and compares with relevant literature. Traditional models usually partition the global universe of discourse, which is not appropriate for all objectives. For example, the universe of the secular trend model is continuously variational. In addition, most forecasting methods rely on prior information, i.e., fuzzy relationship groups (FRG). Numerous relationship groups lead to the explosive growth of relationship library in a linear model and increase the computational complexity. To overcome problems above and ascertain an appropriate order, an intuitionistic fuzzy time series forecasting model based on order decision and adaptive partition algorithm is proposed. By forecasting the vector operator matrix, the proposed model can adjust partitions and intervals adaptively. The proposed model is tested on student enrollments of Alabama dataset, typical seasonal dataset Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) and a secular trend dataset of total retail sales for social consumer goods in China. Experimental results illustrate the validity and applicability of the proposed method for different patterns of dataset.
基金This project was supported by the National Natural Science Foundation of China(60135020) National Key Pre-researchProject of China(413010701 -3) .
文摘A novel reconfigurable hardware system which uses both muhi-DSP and FPGA to attain high performance and real-time image processing are presented. The system structure and working principle of mainly processing multi-BSP board, extended multi-DSP board are analysed. The outstanding advantage is that the communication among different board components of this system is supported by high speed link ports ＆ serial ports for increasing the system performance and computational power. Then the implementation of embedded real-time operating systems （RTOS） by us is discussed in detail. In this system, we adopt two kinds of parallel structures controlled by RTOS for parallel processing of algorithms. The experimental results show that exploitive period of the system is short, and maintenance convenient. Thus it is suitable for real-time image processing and can get satisfactory effect of image recognition.
基金Project(52272339)supported by the National Natural Science Foundation of ChinaProject(2023YFB390730303)supported by the National Key Research and Development Program of China+2 种基金Project(L2023G004)supported by the Science and Technology Research and Development Program of China State Railway Group Co.,Ltd.Project(QZKFKT2023-005)supported by the State Key Laboratory of Heavy-duty and Express High-power Electric Locomotive,ChinaProject(2022JZZ05)supported by the Open Foundation of MOE Key Laboratory of Engineering Structures of Heavy Haul Railway(Central South University),China。
文摘In this paper,a novel train positioning method considering satellite raw observation data was proposed,which aims to promote train positioning performance from an innovative perspective of the train satellite-based positioning error sources.The method focused on overcoming the abnormal observations in satellite observation data caused by railway environment rather than the positioning results.Specifically,the relative positioning experimental platform was built and the zero-baseline method was firstly employed to evaluate the carrier phase data quality,and then,GNSS combined observation models were adopted to construct the detection values,which were applied to judge abnormal-data through the dual-frequency observations.Further,ambiguity fixing optimization was investigated based on observation data selection in partly-blocked environments.The results show that the proposed method can effectively detect and address abnormal observations and improve positioning stability.Cycle slips and gross errors can be detected and identified based on dual-frequency global navigation satellite system data.After adopting the data selection strategy,the ambiguity fixing percentage was improved by 29.2%,and the standard deviation in the East,North,and Up components was enhanced by 12.7%,7.4%,and 12.5%,respectively.The proposed method can provide references for train positioning performance optimization in railway environments from the perspective of positioning error sources.
文摘针对大规模农田的粮食抢收工作,由于抢收约束时间的限制,导致可能无法在规定时间内完成所有粮食的收割任务,此时则会出现粮食损失值。构建以粮食损失值最小化为目标的农机跨区紧急调配模型,提出基于两阶段的农机紧急调配算法(Agricultural Machinery Emergency Algorithm based on Two Stages,TSEA)。首先按照基于距离的分区策略对大规模农田进行分区,接着采用改进的遗传算法分别对各农田分区进行农机紧急作业调配。为验证算法的有效性,主要从紧急任务的粮食损失值、算法运行时间等方面将TSEA算法与GA、SA算法进行比较,试验结果表明,TSEA算法得到的紧急调度方案优于其他两种算法。为验证本文分区策略的有效性,分别采用TSEA算法和不分区的紧急调配算法从粮食损失值、算法运行时间等方面进行比较,验证分区策略的有效性。多组试验结果表明该文提出的策略和算法对于解决大规模农田的农机跨区紧急调配问题更有效,可为农机管理部门提供解决方案。
