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The Design of I/O Subsystem in Satellite Real-Time Microkernel Operating System 被引量:1
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作者 Liu Xiaodong & Li Lianzhi (Dept. of Computer Science & Engineering, Harbin Institute of Technology, 150001, P. R. China) Qian Chunlai(Beijiing Institute of Radio Measurement, 100854, P. R. China) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1998年第3期77-81,共5页
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
关键词 Satellite operating system I/O subsystem OBJECT-ORIENTED real-time
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Weak Serializable Concurrency Control in Distributed Real-Time Database Systems
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作者 党德鹏 刘云生 潘琳 《Journal of Shanghai University(English Edition)》 CAS 2002年第4期325-330,共6页
Most of the proposed concurrency control protocols for real time database systems are based on serializability theorem. Owing to the unique characteristics of real time database applications and the importance of sa... Most of the proposed concurrency control protocols for real time database systems are based on serializability theorem. Owing to the unique characteristics of real time database applications and the importance of satisfying the timing constraints of transactions, serializability is too strong as a correctness criterion and not suitable for real time databases in most cases. On the other hand, relaxed serializability including epsilon serializability and similarity serializability can allow more real time transactions to satisfy their timing constraints, but database consistency may be sacrificed to some extent. We thus propose the use of weak serializability(WSR) that is more relaxed than conflicting serializability while database consistency is maintained. In this paper, we first formally define the new notion of correctness called weak serializability. After the necessary and sufficient conditions for weak serializability are shown, corresponding concurrency control protocol WDHP(weak serializable distributed high priority protocol) is outlined for distributed real time databases, where a new lock mode called mask lock mode is proposed for simplifying the condition of global consistency. Finally, through a series of simulation studies, it is shown that using the new concurrency control protocol the performance of distributed real time databases can be greatly improved. 展开更多
关键词 distributed real time database systems relaxed serializability real time concurrency control read only transactions.
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Design and Research of Distributed Real TimeSurveillance Control System
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《计算机科学与技术汇刊(中英文版)》 2015年第2期40-43,共4页
Distributed real time surveillance control system is used especially in distributed computer measure and control system, mostly inwidely dispersed measure points without human surveillance. This paper describes theory... Distributed real time surveillance control system is used especially in distributed computer measure and control system, mostly inwidely dispersed measure points without human surveillance. This paper describes theory、construction、control strategy, stabilityanalysis of distributed real time supervisory control and data acquisition system, implements distributed measure signals collectionand design of supervisory control system. The realization of virtual instrument based on VC++ can accomplish measurementsignals acquisition, storage, display and analysis, also the result of surveillance control system is provided, and shows thefunctional powerful agility of virtual instrument based on VC++. 展开更多
关键词 real time distributed VIRTUAL Instrument
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A dynamic crash recovery scheme for distributed real-time database systems
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作者 肖迎元 刘云生 +2 位作者 刘小峰 廖国琼 王洪亚 《Journal of Shanghai University(English Edition)》 CAS 2006年第6期510-516,共7页
Recovery performance in the event of failures is very important for distributed real-time database systems. This paper presents a time-cognizant logging-based crash recovery scheme (TCLCRS) that aims at distributed ... Recovery performance in the event of failures is very important for distributed real-time database systems. This paper presents a time-cognizant logging-based crash recovery scheme (TCLCRS) that aims at distributed real-time databases, which adopts a main memory database as its ground support. In our scheme, each site maintains a real-time log for local transactions and the subtransactions, which execute at the site, and execte local checkpointing independently. Log records are stored in non-volatile high- speed store, which is divided into four different partitions based on transaction classes. During restart recovery after a site crash, partitioned crash recovery strategy is adopted to ensure that the site can be brought up before the entire local secondary database is reloaded in main memory. The partitioned crash recovery strategy not only guarantees the internal consistency to be recovered, but also guarantee the temporal consistency and recovery of the sates of physical world influenced by uncommitted transactions. Combined with two- phase commit protocol, TCLCRS can guarantee failure atomicity of distributed real-time transactions. 展开更多
关键词 distributed real-time database system partitioned real-time logging partitioned crash recovery.
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Real-time Operating System of a CNC Machine Tool
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作者 LI Cheng ren(Northwestern PolyteChnical University, Xi’an 710072, China) 《International Journal of Plant Engineering and Management》 1999年第Z1期506-512,共7页
This paper discusses the real-time operating system (RTOS) of a computer numericalcontrol machine tool. It includes the characteristic, structure, function sub-routines, managementand communication.There are mainly t... This paper discusses the real-time operating system (RTOS) of a computer numericalcontrol machine tool. It includes the characteristic, structure, function sub-routines, managementand communication.There are mainly two structures of CNC' RTOS. They are foreground-background type andinterrupt type. In this paper we discuss mainly the method of job management, andcommunicaton of the two types. 展开更多
关键词 operating system real time CNC.
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A Review of Operating System Infrastructure for Real-Time Embedded Software
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作者 Luis Femando Friedrich Mario A. R. Dantas 《通讯和计算机(中英文版)》 2015年第6期273-285,共13页
关键词 嵌入式系统设计 软件操作系统 基础架构 实时 娱乐设备 分布式 价格下降 掌上电脑
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Digital arc welding power supply based on real-time operating system
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作者 张红兵 黄石生 周漪清 《China Welding》 EI CAS 2007年第3期1-5,共5页
A digital arc welding power supply was designed with the advanced reduced instruction set computer machine (ARM) and embedded real-time multi-task operating system micro C/OS- Ⅱ. The ARM, with its powerful calculat... A digital arc welding power supply was designed with the advanced reduced instruction set computer machine (ARM) and embedded real-time multi-task operating system micro C/OS- Ⅱ. The ARM, with its powerful calculating speed and complete peripheral equipments, is very suitable to work as the controller of the digital power supply. The micro C/OS- Ⅱ transplanted in ARM, helps to improve the respondent speed against various welding signals, as well as the reliability of the controlling software. The welding process consists of nine tasks. The tasks of great significance on reliability of the welder, for example, the A/D conversion of current and voltage, enjoy top priority. To avoid simultaneous-sharing on A/D converter and LCD module, two semaphores are introduced in to ensure the smooth performance of the welding power supply. Proven by experiments ,the ARM and the micro C/OS- Ⅱ can greatly improve both the respondent speed and the reliability of the digital welder. 展开更多
关键词 micro C/OS-Ⅱ real-time operating system DIGITIZATION arc welding power supply
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Transmission Considerations with QoS Support to Deliver Real-Time Distributed Speech Recognition Applications
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作者 Zhu Xiao-gang Zhu Hong-wen Rong Meng-tian 《Wuhan University Journal of Natural Sciences》 EI CAS 2002年第1期65-70,共6页
Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless... Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels. 展开更多
关键词 distributed speech recognition quality of service real-time transmission protocol resource reservation protocol wireless application protocol
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Distributed Real-Time Systems on Responsive Link
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作者 Hiroyuki Chishiro Nobuyuki Yamassaki 《通讯和计算机(中英文版)》 2012年第12期1321-1330,共10页
关键词 分布式实时系统 链接 实时操作系统 应用程序接口 通信标准 API IEC 实时性
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Assigning Real-Time Tasks in Environmentally Powered Distributed Systems
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作者 Jian Lin Albert M. K. Cheng 《Circuits and Systems》 2014年第4期98-113,共16页
Harvesting energy for execution from the environment (e.g., solar, wind energy) has recently emerged as a feasible solution for low-cost and low-power distributed systems. When real-time responsiveness of a given appl... Harvesting energy for execution from the environment (e.g., solar, wind energy) has recently emerged as a feasible solution for low-cost and low-power distributed systems. When real-time responsiveness of a given application has to be guaranteed, the recharge rate of obtaining energy inevitably affects the task scheduling. This paper extends our previous works in?[1] [2] to explore the real-time task assignment problem on an energy-harvesting distributed system. The solution using Ant Colony Optimization (ACO) and several significant improvements are presented. Simulations compare the performance of the approaches, which demonstrate the solutions effectiveness and efficiency. 展开更多
关键词 distributed Systems Energy HARVESTING real-time SCHEDULING TASK ASSIGNMENT
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Research on Collaboration Theory of Distributed Measurement System and Real-Time of Communication Platform
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作者 SHENYan 《Journal of Electronic Science and Technology of China》 2005年第1期95-95,共1页
关键词 distributed measurement system agent technology swarm intellgence Particle Swarm Optimization algorithm Collaboration model Switched Ethernet real-time Scheduling AEROENGINE
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Exponential stabilization of distributed parameter switched systems under dwell time constraints
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作者 鲍乐平 费树岷 翟军勇 《Journal of Southeast University(English Edition)》 EI CAS 2013年第4期389-394,共6页
The exponential stabilization problem for finite dimensional switched systems is extended to the infinite dimensional distributed parameter systems in the Hilbert space. Based on the semigroup theory, by applying the ... The exponential stabilization problem for finite dimensional switched systems is extended to the infinite dimensional distributed parameter systems in the Hilbert space. Based on the semigroup theory, by applying the multiple Lyapunov function method, the exponential stabilization conditions are derived. These conditions are given in the form of linear operator inequalities where the decision variables are operators in the Hilbert space; while the stabilization properties depend on the switching rule. Being applied to the two-dimensional heat switched propagation equations with the Dirichlet boundary conditions, these linear operator inequalities are transformed into standard linear matrix inequalities. Finally, two examples are given to illustrate the effectiveness of the proposed results. 展开更多
关键词 distributed parameter switched systems exponential stabilization multiple Lyapunov function linear operator inequalities dwell time
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Boundary Control Problem of Infinite Order Distributed Hyperbolic Systems Involving Time Lags 被引量:2
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作者 Bahaa Gaber Mohamed 《Intelligent Control and Automation》 2012年第3期211-221,共11页
Various optimal boundary control problems for linear infinite order distributed hyperbolic systems involving constant time lags are considered. Constraints on controls are imposed. Necessary and sufficient optimality ... Various optimal boundary control problems for linear infinite order distributed hyperbolic systems involving constant time lags are considered. Constraints on controls are imposed. Necessary and sufficient optimality conditions for the Neumann problem with the quadratic performance functional are derived. 展开更多
关键词 BOUNDARY CONTROL (n × n) Hyperbolic Systems time Lags distributed CONTROL Problems NEUMANN Conditions Existence and UNIQUENESS of Solutions Infinite Order operator
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A Distributed LRTCO Algorithm in Large-Scale DVE Multimedia Systems
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作者 Hangjun Zhou Guang Sun +3 位作者 Sha Fu Wangdong Jiang Tingting Xie Danqing Duan 《Computers, Materials & Continua》 SCIE EI 2018年第7期73-89,共17页
In the large-scale Distributed Virtual Environment(DVE)multimedia systems,one of key challenges is to distributedly preserve causal order delivery of messages in real time.Most of the existing causal order control app... In the large-scale Distributed Virtual Environment(DVE)multimedia systems,one of key challenges is to distributedly preserve causal order delivery of messages in real time.Most of the existing causal order control approaches with real-time constraints use vector time as causal control information which is closely coupled with system scales.As the scale expands,each message is attached a large amount of control information that introduces too much network transmission overhead to maintain the real-time causal order delivery.In this article,a novel Lightweight Real-Time Causal Order(LRTCO)algorithm is proposed for large-scale DVE multimedia systems.LRTCO predicts and compares the network transmission times of messages so as to select the proper causal control information of which the amount is dynamically adapted to the network latency variations and unconcerned with system scales.The control information in LRTCO is effective to preserve causal order delivery of messages and lightweight to maintain the real-time property of DVE systems.Experimental results demonstrate that LRTCO costs low transmission overhead and communication bandwidth,reduces causal order violations efficiently,and improves the scalability of DVE systems. 展开更多
关键词 distributed computing distributed virtual environment multimedia system causality violation causal order delivery real time
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Real-Time Operation of Microgrids
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作者 Salem Al-Agtash Asma Alkhraibat +1 位作者 Mohamad Al Hashem Nisrein Al-Mutlaq 《Energy and Power Engineering》 2021年第1期51-66,共16页
Microgrid (MG) systems effectively integrate a generation mix of solar, wind, and other renewable energy resources. The intermittent nature of renewable resources and the unpredictable weather conditions contribute la... Microgrid (MG) systems effectively integrate a generation mix of solar, wind, and other renewable energy resources. The intermittent nature of renewable resources and the unpredictable weather conditions contribute largely to the unreliability of microgrid real-time operation. This paper investigates the behavior of microgrid for different intermittent scenarios of photovoltaic generation in real-time. Reactive power coordination control and load shedding mechanisms are used for reliable operation and are implemented using OPAL-RT simulator integrated with Matlab. In an islanded MG, load shedding can be an effective mechanism to maintain generation-load balance. The microgrid of the German Jordanian University (GJU) is used for illustration. The results show that reactive power coordination control not only stabilizes the MG operation in real-time but also reduces power losses on transmission lines. The results also show that the power losses at some substations are reduced by a range of 6% - 9.8%. 展开更多
关键词 Microgrid real-time operation Reactive Power Control Load Shedding OPAL-RT MATLAB
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Low-Power Operational Amplifier for Real-Time Signal Processing System of Micro Air Vehicle
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作者 王竹萍 仲顺安 聂丹丹 《Journal of Beijing Institute of Technology》 EI CAS 2010年第3期353-356,共4页
A low-power complementary metal oxide semiconductor(CMOS) operational amplifier (op-amp) for real-time signal processing of micro air vehicle (MAV) is designed in this paper.Traditional folded cascode architectu... A low-power complementary metal oxide semiconductor(CMOS) operational amplifier (op-amp) for real-time signal processing of micro air vehicle (MAV) is designed in this paper.Traditional folded cascode architecture with positive channel metal oxide semiconductor(PMOS) differential input transistors and sub-threshold technology are applied under the low supply voltage.Simulation results show that this amplifier has significantly low power,while maintaining almost the same gain,bandwidth and other key performances.The power required is only 0.12 mW,which is applicable to low-power and low-voltage real-time signal acquisition and processing system. 展开更多
关键词 microelectromechanical system(MEMS) operational amplifier(op-amp) LOW-POWER real-time signal processing system micro air vehicle(MAV)
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Multi-Threat Real-Time Separating System 被引量:2
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作者 詹磊 赵建民 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2001年第4期23-27,共5页
This paper describes a multi-threat real-time separating system for broadband anti-radiation missile seeker. It presents a method, with a dual-port memory as comparer, to perform PF and PW hardware real-time separatio... This paper describes a multi-threat real-time separating system for broadband anti-radiation missile seeker. It presents a method, with a dual-port memory as comparer, to perform PF and PW hardware real-time separation and to determine the time-of-arrival (TOA) by use of sequential difference histogram (SDIF). The method has been applied to practice, which has achieved good results. 展开更多
关键词 Binary codes Frequencies Poisson distribution Pulse width modulation Random access storage real time systems
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A Concept of Dynamically Reconfigurable Real-time Vision System for Autonomous Mobile Robotics 被引量:3
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作者 Aymeric De Cabrol Thibault Garcia +1 位作者 Patrick Bonnin Maryline Chetto 《International Journal of Automation and computing》 EI 2008年第2期174-184,共11页
This paper describes specific constraints of vision systems that are dedicated to be embedded in mobile robots. If PC-based hardware architecture is convenient in this field because of its versatility, flexibility, pe... This paper describes specific constraints of vision systems that are dedicated to be embedded in mobile robots. If PC-based hardware architecture is convenient in this field because of its versatility, flexibility, performance, and cost, current real-time operating systems are not completely adapted to long processing with varying duration, and it is often necessary to oversize the system to guarantee fail-safe functioning. Also, interactions with other robotic tasks having more priority are difficult to handle. To answer this problem, we have developed a dynamically reconfigurable vision processing system, based on the innovative features of Cleopatre real-time applicative layer concerning scheduling and fault tolerance. This framework allows to define emergency and optional tasks to ensure a minimal quality of service for the other subsystems of the robot, while allowing to adapt dynamically vision processing chain to an exceptional overlasting vision process or processor overload. Thus, it allows a better cohabitation of several subsystems in a single hardware, and to develop less expensive but safe systems, as they will be designed for the regular case and not rare exceptional ones. Finally, it brings a new way to think and develop vision systems, with pairs of complementary operators. 展开更多
关键词 real-time vision dynamic reconfiguration embedded systems ROBUSTNESS real-time operating system
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A Model Predictive Scheduling Algorithm inReal-Time Control Systems 被引量:2
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作者 Mengya Kang Chenglin Wen Chenxi Wu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第2期471-478,共8页
Abstract-The ineffective utilization of power resources has attracted much attention in current years. This paper proposes a real-time distributed load scheduling algorithm considering constraints of power supply. Fir... Abstract-The ineffective utilization of power resources has attracted much attention in current years. This paper proposes a real-time distributed load scheduling algorithm considering constraints of power supply. Firstly, an objective function is designed based on the constraint, and a base load forecasting model is established when aggregating renewable generation and non-deferrable load into a power system, which aims to transform the problem of deferrable loads scheduling into a distributed optimal control problem. Then, to optimize the objective function, a real-time scheduling algorithm is presented to solve the proposed control problem. At every time step, the purpose is to minimize the variance of differences between power supply and aggregate load, which can thus ensure the effective utilization of power resources. Finally, simulation examples are provided to illustrate the effectiveness of the proposed algorithm. 展开更多
关键词 Index Terms-Deferrable loads scheduling electric vehicles(EVs) optimal control power supply real-time distributed con-trol.
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e-Automation,an Architecture for Distributed Industrial Automation Systems
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作者 D.P.Buse J. Fitch 《International Journal of Automation and computing》 EI 2004年第1期17-25,共9页
Due to the complexity of modern industrial systems, a conventional automation system is not capable of providing sufficient information management and high-level intelligent approaches, as achieving these functionalit... Due to the complexity of modern industrial systems, a conventional automation system is not capable of providing sufficient information management and high-level intelligent approaches, as achieving these functionalities requires the support of comprehensive data management and coordination between system devices and heterogenous information. This paper proposes the concept of e-Automation, in which computer networking and distributed intelligence agent technologies are applied to industrial automation systems, and presents a hardware and software architecture that implements this concept. An open infrastructure based on multi-agent systems is employed in the proposed architecture of e-Automation, which aims to allow the implementation of diverse tasks and to permit greater configurability than can be obtained from a traditional system. To evaluate our proposed e-Automation concept, this paper presents a case study of substation information management which adopts the proposed e-Automation architecture in power system domain. 展开更多
关键词 Intelligent agents multi agent system distribute system e AUTOMATION monitoring system real time control
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