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.
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.
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.
35136972
Exact Best-Case End-to-End Response Time Analysis for Hard Real-Time Distributed Systems
The prediction of best-case response time is quite necessary to guarantee control accuracy and stability of distributed hard real-time systems. Published time analysis techniques can precisely dealt with the precedence relations between tasks on different processors, but usually ignored or inaccurately estimated the effects from the precedence relations between tasks on the same processor. This leads to a pessimistic analysis. This paper presents an algorithm to analyze the best-case end-to-end response time for hard real-time distributed systems. This algorithm extends the traditional analysis technique by exploiting the precedence relations between tasks on both different processors and the same processor and achieves a more accurate analysis. Simulation results have shown that this algorithm can achieve more accurate results than existing methods.
18111881
Worst-Case Response Time Analysis for OSEK/VDX Compliant Real-Time Distributed Control Systems
Temporal behaviors prediction is very critical for real-time control systems. This paper presents a method to analysis the worst-case response time of OSEK/VDX compliant hard real-time distributed control systems. OSEK/VDX is an industry standard for an open-ended architecture for distributed control units in vehicles. Traditional time analysis methods based on the fixed priority preemptive scheduling model do not account for the problems occur in practical systems. Based on the current time analysis technologies, we propose an accurate time analysis method considering the practical effects of resource access synchronization, mixed preemptive and non-preemptive scheduling, as well as the overheads of OSEK OS. Furthermore, we also propose a scheme to efficiently integrate time analysis tools into the current development process for electronic control units in vehicles.
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.
27385183
Standard Deviation and Intra Prediction Mode Based Adaptive Spatial Error Concealment (SEC) in H.264/AVC
Transmission of compressed video over error prone channels may result in packet losses or errors, which can significantly degrade the image quality. Therefore an error concealment scheme is applied at the video receiver side to mask the damaged video. Considering there are 3 types of MBs (Macro Blocks) in natural video frame, i.e., Textural MB, Edged MB, and Smooth MB, this paper proposes an adaptive spatial error concealment which can choose 3 different methods for these 3 different MBs. For criteria of choosing appropriate method, 2 factors are taken into consideration. Firstly, standard deviation of our proposed edge statistical model is exploited. Secondly, some new features of latest video compression standard H.264/AVC, i.e., intra prediction mode is also considered for criterion formulation. Compared with previous works, which are only based on deterministic measurement, proposed method achieves the best image recovery. Subjective and objective image quality evaluations in experiments confirmed this.
14688887
Data Compression Algorithm Based on Hierarchical Cluster Model for Sensor Networks
A new distributed algorithm of data compression based on hierarchical cluster model for sensor networks is proposed, in which, the whole sensor network is mapped into a kind of hierarchical clusters model firstly, and then different wavelet transform models are used to commit data compression in inner and super clusters respectively. Theoretical analyses and simulation results show that, the above new methods have good performance of approximation, and can compress data and reduce the amount of data efficiently.
12523556
Design Patterns of Scalable Cluster System Software
The design pattern of cluster system software has an important influence on scalability of massive cluster system. The paper presents design patterns of scalable cluster system software, including scalable software topologies and optimized communication modes. These design patterns have been widely applied in Dawning series of supercomputers and some results of performance evaluation show their good scalability
95638
MU-MAQAS: A P2P based Model Updatable Mobile Automatic Q/A System
Along with the development of wireless technology and especially 3Gpsilas throw into commercial, the mobile value-added services gradually popular used, such as mobile automatic question and answer (Q/A) system. But the current mobile Q/A system mainly based on FAQ database, the question and answer can not be validated and updated by itself. So this paper attempts to implement a p2p based model updatable automatic Q/A system named MU-MAQAS for mobile phones using SMS interface. MU-MAQAS mainly includes: question & answer information collecting module and model manage & use module. It can automatically collect Q/A information from internet and update the Q/A model in time. A simulated Q/A system is also coded to validate the design. Results of simulation proved that under ideal conditions the systempsilas average responding time is less than 64 ms and precision is above 60% when there are no more than 3000 simultaneous asking queries, and so the completeness and feasibility of the systempsilas design is proved.
6760959
A semantic representation for image retrieval
Robust semantic labeling of image regions is a basic problem in representing and retrieving image/video content. We propose an SVM-MRF framework to model features and their spatial distributions, leading towards a "semantic" representation. Eigenfeatures of Gabor wavelet features and Gaussian mixture model are used for feature clustering. Since similar feature vectors in one cluster can come from several different semantic classes, SVM is applied to represent conditioned feature vector distributions within each cluster, and a Markov random field is used to model the spatial distributions of the semantic labels. A semantic layout representation is proposed to describe the semantics of the images. Experiments show that this method can improve semantic labeling and is useful in similarity search.