5460989
End-To-End Worst-Case Response Time Analysis for Hard Real-Time Distributed Systems
The verification of end-to-end response time for distributed hard real-time systems is quite necessary for safety-critical applications. Although current time analysis techniques can precisely analyze the response time, the performance is not quite satisfying, especially for large size distributed systems. This paper presents a novel end-to-end worst-case response time analysis approach for hard real-time distributed systems. This technique is based on the critical instant analysis and the canonical form transformation. It extends the traditional holistic analysis technique by exploiting the precedence relations between tasks on both different processors and the same processor. Simulation results have shown that this algorithm can achieve accurate results and offers good performance for systems with wide range of CPU utilizations and task set size, and therefore is applicable to schedulability analysis of complex distributed systems.
17996623
Fault tolerant scheduling for fixed-priority tasks with preemption threshold
Fixed-priority with preemption threshold (FPPT) is an important form of real-time scheduling algorithm, which fills the gap between fixed-priority preemptive (FPP) and fixed-priority non-preemptive (FPNP). However, this scheduling scheme together with the requirements of fault tolerance makes the prediction of a real-time system's behaviors more difficult than traditional scheduling scheme. The major contribution of this work is twofold. First, we present an appropriate schedulability analysis, based on response time analysis, for supporting fault-tolerant FPPT scheduling in hard real-time systems. The error-recovery techniques are considered to be used to carry out fault tolerance. Second, we propose the optimal priority assignment algorithm which can be used, together with the schedulability analysis, to improve system fault resilience.
9201590
A Reliable OS Kernel for Smart Sensors
206594316
An OSEK COM Compliant Communication Model for Smart Vehicle Environment
Smart Vehicle Environment (SVE) is an important application of the idea of smart spaces. This paper presents Smart Vehicle Multi-Agent System (SVMAS) to achieve the goal of SVE and put forwards a commutation model for SVMAS based on SmartOSEK COM [1] to support data exchange. The paper also presents an approach to encapsulate the message to transport by CAN bus, and bring forward a simulator model for SVMAS. Finally the paper gives an example of the communication model which implements a dialogue between two agents and analyzes the performance. The contribution of our work is threefold. First, we adopt Knowledge Query and Manipulation Language (KQML) to describe the communication in vehicles. Second, we develop SmartOSEK COM to implement communication in vehicles. Third, we define the ACLcan protocol to transform the message from SmartOSEK COM to CAN frame.
28662296
A Service Oriented Implementation of Distributed Status Monitoring and Fault Diagnosis Systems
The service-oriented architecture (SOA) can greatly improve the collaboration of devices in a distributed environment. With this architecture, human can be liberated from the burdensome configuration and management of distributed systems, especially when the nodes of the systems are dynamically changed. In this paper, we present a method to implement service-oriented distributed systems in industry. As a case study, we present a service-oriented Status Monitoring and Fault Diagnosis Systems (SMFDS) for large equipment. Our work is based on the UPnP (Universal Plug and Play) technology. Through abstracting the interfaces of devices and providing service middleware in an independent thread or process, the SOA can be easily implemented on an existing system with the least modifications. This characteristic is very useful when upgrading an existing system, for cost and risk consideration.
35028524
SmartOSEK: A Real-Time Operating System for Automotive Electronics
This paper puts forward SmartOSEK, a dependable platform for automobile electronics, which consists of an operating system compliant with OSEK/VDX specifications and an integrated development environment (IDE) that consists of many convenient tools, such as visual designer, system generator, time analyst, scheduling analyst, and running tracer. In the operating system, SmartOSEK OS and SmartOSEK COM are presented. In the IDE, we apply the graphic design, automatic code generation and time analysis to help developers devote their mind to the modeling of the applications. A design example of automated transmission system based on SmartOSEK platform is given, and good results are achieved.
15780361
The Real-Time Networked Data Gathering Systems Based on EtherCAT
Distributed control systems have been growing explosively and the Fieldbus technology has been widely employed for networked data gathering system. However, few Field-bus is real time down to the I(Input)/O(Output) level and most of them have a large number of sub-systems. In this paper we introduce a novel high-speed industry Ethernet bus known as EtherCAT into data gathering system. A networked data gathering system based on EtherCAT is achieved and the experimental results indicate the system can perform well in real-time data transmission.
11702603
Active network supports for mobile IP
The basic mobile IP protocol is difficult to implement on the traditional IP network and not flexible and efficient under certain conditions. For example, firewalls or boundary routers may drop packets sent by mobile nodes for security reasons. Traditional networking devices such as routers cannot dynamically load and unload extended services to achieve different qualities of services. In this paper, a new scheme of using the active network to support the mobile IP is presented. The Softnet, a prototype of active networks based on mobile agents, is introduced. The active network is characterized by the programmability of its intermediate nodes and therefore presents dynamic and flexible behaviors. Special services can be dynamically deployed onto the active nodes in the Softnet. This property is definitely required in implementing the mobile IP protocols. The Softnet supports not only the basic mobile IP protocol but also other extended mobile IP protocols. Virtual networks for mobile IP services are dynamically formed by mobile agents in the Softnet to provide different qualities of services.
2723209
An energy-efficient skew compensation technique for high-speed skew-sensitive signaling
Presented in this paper is an energy-efficient skew compensation technique referred to as the resistance-based distributed clock deskew (RDSK) technique. In comparison with the existing clock deskew techniques, the proposed RDSK technique achieves significant power reduction while maintaining effective in skew management. Furthermore, the proposed RDSK provides a better scalability for future technology scaling. Simulation results of an on-chip interconnect communication system with distributed receivers designed in a 0.10 /spl mu/m CMOS process demonstrate 20%-51% power reduction over the existing techniques. The proposed RDSK is an essential element of our adaptive timing framework where circuit performance can be adjusted adaptively in response to time-varying disturbances and uncertainties.
7231768
Two Criteria for Model Selection in Multiclass Support Vector Machines
Practical applications call for efficient model selection criteria for multiclass support vector machine (SVM) classification. To solve this problem, this paper develops two model selection criteria by combining or redefining the radius-margin bound used in binary SVMs. The combination is justified by linking the test error rate of a multiclass SVM with that of a set of binary SVMs. The redefinition, which is relatively heuristic, is inspired by the conceptual relationship between the radius-margin bound and the class separability measure. Hence, the two criteria are developed from the perspective of model selection rather than a generalization of the radius-margin bound for multiclass SVMs. As demonstrated by extensive experimental study, the minimization of these two criteria achieves good model selection on most data sets. Compared with the k-fold cross validation which is often regarded as a benchmark, these two criteria give rise to comparable performance with much less computational overhead, particularly when a large number of model parameters are to be optimized.
33446676
Voronoi Tessellation Based Rapid Coverage Decision Algorithm for Wireless Sensor Networks
The coverage problem is a fundamental issue in the research of sensor network. A novel Voronoi tessellation based rapid coverage decision algorithm is proposed, in which the region of interest is partitioned into some square grids firstly, and then the complex area coverage problem is transformed into simple vertices coverage problem, on the basis of the good characteristics of Voronoi tessellation such as being able to divide the planner area into a set of simple geometric simplexes. Theoretical analysis and simulation results show that, the new algorithm can decrease the computation complexity of networks, especially for sensor networks with n different sensors, it can solve the coverage problem correctly for any given region of interest with time costs of O(nlogn) only.