Caching technique has been widely used to accelerate data access for Location Dependent Information Services (LDISs) in mobile environments. Many existing LDISs focuse primarily on finding the nearest object. However,...
详细信息
In object-oriented programs, we often need to set some restrictions on the temporal orders of the message receiving for objects, which forms a class of safety requirements. In this paper, we use UML state machine diag...
详细信息
ISBN:
(纸本)9781595937537
In object-oriented programs, we often need to set some restrictions on the temporal orders of the message receiving for objects, which forms a class of safety requirements. In this paper, we use UML state machine diagrams as design specifications, and present an approach to runtime verification of Java programs, which is focused on the temporal order of message receiving based consistency verification between the behavior of state machine diagrams and the program execution traces. In the approach, we first instrument the program under verification so as to gather the program execution traces related to a given state machine diagram. Then we drive the instrumented program by random test cases so as to generate the program execution traces. Finally we check if the collected program execution traces are consistent with the behavior of the state machine diagram, which means that the temporal orders of the message receiving occurring in the program traces are consistent with the ones occurring in the state machine diagram. Our approach can be used to detect not only the program bugs resulting from the wrong temporal orders of message receiving, but also the imperfect state machine models constructed in reverse engineering for legacy systems, and loads to a testing tool which may proceed in a fully automatic fashion. Copyright 2008 ACM.
Self-organization is the key to implement self-calibration, autonomously coordination and p2p communication in sensor networks. Current researches mainly solve this problem in an inappropriate pre-planned manner. The ...
详细信息
It is well-known that diversity among base classifiers is crucial for constructing a strong ensemble. Most existing ensemble methods obtain diverse individual learners through resampling the instances or features. In ...
A large number of web pages returned by filling in search forms are not indexed by most search engines today. The set of such web pages is referred to as the Deep Web. Since results returned by web databases seldom ha...
详细信息
Average reward reinforcement learning is an important undiscounted optimality framework. However, most of the work was based on discrete state space tasks. In this paper, how to combine function approximation with ave...
详细信息
Average reward reinforcement learning is an important undiscounted optimality framework. However, most of the work was based on discrete state space tasks. In this paper, how to combine function approximation with average reward learning is studied, and the parameter update condition is modified according to the continuous space. Besides, a close study on the performance of G-learning and its insensitivity to learning parameters is made. Finally, experimental results and relevant analysis are presented. The experimental results validate the solutions of R-learning and G-learning are prone to diverge when Ε is relatively small. And the results also show that the Tile Coding is effective in function approximation as a feature extraction method and it can be taken as a comparative standard for other methods.
Modern component-based systems consist of active components that execute in parallel, which brings great difficulties in verifying correctness. By extending component calculus, a theory concerning refinement of active...
详细信息
Modern component-based systems consist of active components that execute in parallel, which brings great difficulties in verifying correctness. By extending component calculus, a theory concerning refinement of active components is proposed. For interfaces, contracts are introduced which give functional specifications for both public methods and active action in terms of guarded designs. Then, a contract's dynamic behavior is defined by a pair of divergences/failures sets. The refinement relation between contracts is defined as the set inclusion of their divergences/failures sets. The theories applying simulation techniques to assure the refinement relation are proved. By defining the semantics of a component as a mapping from the contract of its required interface to the contract of its provide interface, component refinement can be proved in terms of contract refinement. When the component- based systems are being constructed in a bottom-up manner, the application of the refinement method together with the composition rule can guarantee their correctness.
Overlay Web caching (OCC) exploits resources of peers to provide scalable and cost-effective web caching service. In a typical OCC system, which is often characterized by highly heterogeneous node capacities and skewe...
详细信息
Overlay Web caching (OCC) exploits resources of peers to provide scalable and cost-effective web caching service. In a typical OCC system, which is often characterized by highly heterogeneous node capacities and skewed query distributions, the resources of each node may be utilized in an unbalanced manner, i.e., some nodes are overloaded and become 'hotspots'. Unfortunately, there are no effective load balancing mechanisms in existing OCC systems to relief the 'hotspots'. This paper proposes a hotspots-free OCC scheme called HFOCC for multimedia content delivery service. Through replicating 'hot' objects adaptively to lightly loaded nodes, loads are distributed more evenly across the whole network. Consequently, the hotspots are relieved. In order to utilize cache resource more effectively, HFOCC splits a node's cache space dynamically into two parts, namely the home cache and the replica cache, and manages them by a uniform policy. With a 'soft' lifetime control mechanism, the redundant object replicas are deleted adaptively, and the system performs well under dynamically changing workloads. Experimental results show that HFOCC improves resource utilization and system throughput markedly.
In order to collect plenty of samples and retain their distinguishability in online sketchy symbol recognition, this paper proposes a detector-generation based clonal selection algorithm and the evaluation approach. T...
详细信息
In order to collect plenty of samples and retain their distinguishability in online sketchy symbol recognition, this paper proposes a detector-generation based clonal selection algorithm and the evaluation approach. The algorithm generates detectors with a r-contiguous-bits unchanged rule (r-CBUR) and p-receptor editing to search in a wider feature space and try to avoid the local convergences. Hand-written Chinese characters are selected as the experimental samples, and the influence of the training parameters are analyzed. The experiments show the improvements of the training process and the classification results of sketchy symbol recognition.
According to the principle of 'Separation of Concerns', by investigating the similarity between multi-view software process modeling and object Petri nets, this paper proposes the MOPN-SP-net model which is a ...
详细信息
According to the principle of 'Separation of Concerns', by investigating the similarity between multi-view software process modeling and object Petri nets, this paper proposes the MOPN-SP-net model which is a multi-view software process model based on object Petri nets and enhances the reusability of software process model. During process modeling, MOPN-SP-net is a multi-dimensional Petri net, which is difficult to analyze directly. So, this paper provides a translation rule from an object Petri net to an equivalent traditional flat Petri net. The translation preserves the soundness property. According to the translation rule, the soundness property of the MOPN-SP-net can be indirectly analyzed by its translated flat net.
暂无评论