In this paper, we propose a new approach for efficient and real-time tracking of the moving objects in sensor networks by mining the movement log. In our approach, we first conduct the hierarchical clustering to form ...
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this paper presents a Hierarchical Scheduling Framework (HSF) recorder for Linux-based operating systems. the HSF recorder is a loadable kernel module that is capable of recording tasks and servers without requiring a...
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ISBN:
(纸本)9780769545028
this paper presents a Hierarchical Scheduling Framework (HSF) recorder for Linux-based operating systems. the HSF recorder is a loadable kernel module that is capable of recording tasks and servers without requiring any kernel modifications. Hence, it complies withthe reliability and stability requirements in the area of embeddedsystems where proven versions of Linux are preferred. the recorder is built upon the loadable real-time scheduler framework RESCH (real-time SCHeduler). We evaluate our recorder by comparing the overhead of this solution against another (patched) recorder. Also, the tracing accuracy of the HSF recorder is tested by running a media-processing task together with periodic real-time Linux tasks in combination with servers. the tests are recorded withthe HSF recorder, and the Ftrace recorder, in order to show the correctness of the experiments and the HSF recorder itself.
the concept of graceful degradation in mixed-criticality real-timesystems is still struggling to reach a widely accepted, global view. Numerous results have emerged in this field during the last years, but there is s...
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ISBN:
(纸本)9781665441889
the concept of graceful degradation in mixed-criticality real-timesystems is still struggling to reach a widely accepted, global view. Numerous results have emerged in this field during the last years, but there is still a lot of work to do. this paper comes with an addition to a recent work [2] in the field of scheduling in semi-clairvoyant systems: it introduces a new criterion for determining which low criticality jobs should be switched upon a system criticality mode transition.
embeddedsystems are usually resource limited in terms of processing power, memory, and power consumption, thus embedded TCP/IP should be designed to make the best use of limited resources. Applying zero-copy mechanis...
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this paper presents RapidRT, a novel statistical approach to Worst-Case Response-time (WCRT) analysis targeting complex embeddedreal-timesystems. the proposed algorithm combines Extreme Value theory (EVT) and other ...
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ISBN:
(纸本)9780769541556
this paper presents RapidRT, a novel statistical approach to Worst-Case Response-time (WCRT) analysis targeting complex embeddedreal-timesystems. the proposed algorithm combines Extreme Value theory (EVT) and other statistical methods in order to produce a probabilistic WCRT estimate. this estimate is calculated using response time data from either Monte Carlo simulations of a detailed model of the system, or from response-time measurements of the real system. the method could be considered as a pragmatic approach intended for complex industrial systems withreal-time requirements. the target systems contain tasks with many intricate dependencies in their temporal behavior, which violates the assumptions of traditional analytical methods for response time analysis and thereby makes them overly pessimistic. An evaluation is presented using two simulation models, inspired by an industrial robotic control system, and five other methods as reference.
A dual-OS platform can efficiently implement emerging mixed-criticality systems by consolidating a real-time OS (RTOS) and a general-purpose OS (GPOS). Although the dual-OS platform attracts increasing attention, it o...
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ISBN:
(数字)9781665453448
ISBN:
(纸本)9781665453448
A dual-OS platform can efficiently implement emerging mixed-criticality systems by consolidating a real-time OS (RTOS) and a general-purpose OS (GPOS). Although the dual-OS platform attracts increasing attention, it often suffers from energy inefficiency in the GPOS for guaranteeing real-time responses of the RTOS. this paper proposes an energy minimization method called DVFS virtualization, which allows running multiple DVFS policies dedicated to the RTOS and GPOS, respectively. the experimental evaluation using a commercial processor showed that the proposed hardware could change the supply voltage within 500 ns and reduce the energy consumption of typical applications by 60% in the best case compared to conventional dual-OS platforms.
Cyber Physical systems are composed of many embeddedsystems which monitor and control the physical processes for tight integrations of computation and physical processes. Such embeddedsystems require not only real-t...
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ISBN:
(纸本)9780769545028
Cyber Physical systems are composed of many embeddedsystems which monitor and control the physical processes for tight integrations of computation and physical processes. Such embeddedsystems require not only real-time capabilities but also high throughput and low power consumption. High throughput is mainly achieved by parallel architectures such as Simultaneous Multithreading (SMT) and Chip Multiprocessor (CMP), and low power consumption is mainly achieved by real-time Dynamic Voltage and Frequency Scaling (RT-DVFS) under the real-time constraint. In this paper, we present a RT-DVFS algorithm called Hetero Efficiency to Logical Processor (HeLP) which can reduce power consumption easily and effectively in prioritized SMT processors. We also present Hetero Efficiency to Logical Processor with Temporal Migration (HeLP-TM) which applies the temporal migration technique to HeLP. Simulation results show that HeLP can reduce power consumption effectively and HeLP-TM is more effective than HeLP.
the Elastic Mixed-Criticality (E-MC) task model and an Early-Release EDF (ER-EDF) scheduling algorithm have been studied to address the service interruption problem for low-criticality tasks in uniprocessor systems. I...
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ISBN:
(纸本)9781479908509
the Elastic Mixed-Criticality (E-MC) task model and an Early-Release EDF (ER-EDF) scheduling algorithm have been studied to address the service interruption problem for low-criticality tasks in uniprocessor systems. In this paper, focusing on multicore systems, we first investigate the schedulability of E-MC tasks under partitioned-EDF (P-EDF) by considering various task-to-core mapping heuristics. then, with and without task migrations being considered, we study both global and local early-release schemes. Compared to the state-of-the-art Global EDF-VD scheduler, the superior performance of the proposed schemes in terms of improving the service levels of low-criticality tasks is confirmed through extensive simulations.
In real-timetheory, basically two approaches for the computation of response-times exist. One of them is the busy window method, the other is the real-time calculus, an extension of the network calculus. While both c...
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ISBN:
(纸本)9780769541556
In real-timetheory, basically two approaches for the computation of response-times exist. One of them is the busy window method, the other is the real-time calculus, an extension of the network calculus. While both can be used to compute the bounds of response-times, they have different properties that make them suitable for different system architectures. the busy window approach on the one hand is able to obtain tight bounds for scheduling policies like round-robin. It is also capable of considering offsets, therefore delivering better results in the relevant cases. Hierarchical scheduling on the other hand can be better accounted for by the real-time calculus, where this is an inherent feature of the underlying concept. the approach we present in this paper takes the theory of hierarchy from the realtime calculus and uses it to generalize the response-time analysis. this is implemented as an extension of the busy window method, which enables it to analyze scheduling hierarchies of an arbitrary depth.
Due to the severe consequences of their possible failure, robotic systems must be rigorously verified against (i) behavioral properties, such as safety and (ii) real-time properties, such as schedulability, while taki...
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ISBN:
(数字)9781728144030
ISBN:
(纸本)9781728144030
Due to the severe consequences of their possible failure, robotic systems must be rigorously verified against (i) behavioral properties, such as safety and (ii) real-time properties, such as schedulability, while taking into account the real hardware (e.g. number of cores) and operating system (e.g. scheduling policy) specificities. Formal verification and schedulability analysis are popular approaches that may help with such verification, but suffer from limitations such as scalability issues (for the former) and difficulty to generalize to complex robotic tasks (for the latter), when used independently. In this paper, we propose a two-step, efficient solution that combines both approaches. the first step provides a sufficient condition for the schedulability of hard-real-time tasks in a robotic application. then, the second step automatically generates a formal model of the application, on which other important properties may be verified formally using statistical model checking. the solution is applied to an autonomous drone case study.
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