A nonparametric regression model with fixed design and linear process errors is considered in this paper. Based on polynomial spline estimation, optimal global rate of convergence of the estimator of nonlinear trend f...
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According to acquisition data of passenger flow relay on artificial and transporting of unreal-time, this paper introduces system of acquisition data of passenger flow base on GPRS by infrared transducer and pressure ...
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Intelligent transportation systems (ITS) make use of wireless communication technologies to provide traffic efficiency and road safety without altering the existing road infrastructure. To really impact on traffic man...
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ISBN:
(纸本)9781424480166
Intelligent transportation systems (ITS) make use of wireless communication technologies to provide traffic efficiency and road safety without altering the existing road infrastructure. To really impact on traffic management, ITS should act in real-time, requiring updated traffic information;hence, the collection of small amounts of information frequently transmitted from a high number of vehicles is needed. Cellular systems represent the most suitable technological solution to achieve this service, since they do not require any further installation of network infrastructures. However, they were designed for different applications: voice, web browsing or e-mailing. In this paper we aim at discussing the feasibility of frequent acquisition of small amount of data from vehicles through the universal mobile telecommunication system (UMTS), and at investigating its impact on the services already provided by the network. Numerical results are obtained by means of simulations, paying particular attention to realistic scenarios, both in terms of wireless systems and users mobility.
The aim of this paper is to introduce LinCAN, a CAN driver system for Linux, developed at the Department of Control Engineering of the Czech Technical University in Prague, and to provide a thorough comparison with So...
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Providing QoS and performance guarantees to arbitrarily divisible loads has become a significant problem for many cluster-based research computing facilities. While progress is being made in scheduling arbitrarily div...
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Providing QoS and performance guarantees to arbitrarily divisible loads has become a significant problem for many cluster-based research computing facilities. While progress is being made in scheduling arbitrarily divisible loads, current approaches are not efficient and do not scale well. In this paper, we propose a linear algorithm for real-time divisible load scheduling. Unlike existing approaches, the new algorithm relaxes the tight coupling between the task admission controller and the task dispatcher. By eliminating the need to generate exact schedules in the admission controller, the algorithm avoids high overhead. We experimentally evaluate the new algorithm. Simulation results demonstrate that the algorithm scales well, can schedule large numbers of tasks efficiently, and performs similarly to existing approaches in terms of providing real-time guarantees.
Power consumption has become a major design constraint in the embedded systems domain and techniques such as dynamic voltage and frequency scaling (DVFS) have emerged to enhance the system's power and energy effic...
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Process Control Systems (PCS) are embarking on a new wave of opportunities driven by Information technology (IT) developments in infrastructure and system integration. Currently, most hydrocarbon process control syste...
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In this paper we are interested in mixed hard/soft real-time fault-tolerant applications mapped on distributed heterogeneous architectures. We use the Earliest Deadline First (EDF) scheduling for the hard real-time ta...
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In this paper we are interested in mixed hard/soft real-time fault-tolerant applications mapped on distributed heterogeneous architectures. We use the Earliest Deadline First (EDF) scheduling for the hard real-time tasks and the Constant Bandwidth Server (CBS) for the soft tasks. The bandwidth reserved for the servers determines the quality of service (QoS) for soft tasks. CBS enforces temporal isolation, such that soft task overruns do not affect the timing guarantees of hard tasks. Transient faults in hard tasks are tolerated using checkpointing with rollback recovery. We have proposed a Tabu Search-based approach for task mapping and CBS bandwidth reservation, such that the deadlines for the hard tasks are satisfied, even in the case of transient faults, and the QoS for the soft tasks is maximized. Researchers have used fixed execution time models, such as the worst-case execution times for hard tasks and average execution times for soft tasks. However, we show that by using stochastic execution times for soft tasks, significant improvements can be obtained. The proposed strategy has been evaluated using an extensive set of benchmarks.
The management of tasks is an essential requirement in most real-time and embedded systems, but invariably leads to unwanted CPU overheads. This paper is concerned with task management in real-time and embedded system...
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The management of tasks is an essential requirement in most real-time and embedded systems, but invariably leads to unwanted CPU overheads. This paper is concerned with task management in real-time and embedded systems employing the Earliest Deadline First (EDF) scheduling algorithm. Currently, the best known techniques to manage EDF scheduling lead to overheads with complexity O(log n), where n is the number of recurring (periodic/sporadic) tasks. In this paper it will be shown that if both the ready and waiting queues are represented by either i) timing and indexed deadline wheels or ii) digital search trees, then all scheduling decisions may be made in time proportional to the logarithm of the largest time representation required by the system, p m . In cases where p m is relatively small, for example in some embedded systems, extremely efficient task management may then be achieved. Experimental results are then presented, and it is shown that on an ARM7 microcontroller, when the number of tasks is comparatively large for such a platform (> 250), the worst-case scheduling overheads remain effectively constant and below 20 ¿s. The results indicate that the techniques provide some improved performance over previous methods, and also seem to indicate that there is little discernable difference between the overheads incurred between employing a fixed- or dynamic-priority scheduler in a given system.
Wireless Body Area Networks (WBAN) has emerged as a key technology to provide real-time health monitoring of a patient and to diagnose and treat many life threatening diseases. WBAN operates in close vicinity to, on, ...
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