17432425
Structure analysis for dynamic software architecture
The open and dynamic Internet environment greatly urges software entities that are distributed on different locations to coordinate with each other to accomplish a computing task. Software architecture is applied to abstract the software entities to be components and the coordination between them to be connectors and then a model is extracted as the architecture on which the design, analysis and verification are based. Currently, the notion of dynamic software architectures that can modify their architecture and enact modifications during the system execution has become one of the most active research areas. In this paper, we focus on the dynamic evolution of system structure other than coordination mechanisms (e.g. communication protocols). It is widely recognized that some restrictions should be imposed on the system evolution to ensure that the system structure may remain one style or transform within a scope. These conditions, to a large extent, make the system execute under control as expected.
7864516
On Finite Alphabets and Infinite Bases III: Simulation
This paper studies the (in)equational theory of simulation preorder and equivalence over the process algebra BCCSP. We prove that in the presence of a finite alphabet with at least two actions, the (in)equational theory of BCCSP modulo simulation preorder or equivalence does not have a finite basis. In contrast, in the presence of an alphabet that is infinite or a singleton, the equational theory for simulation equivalence does have a finite basis.
8665982
Structure analysis for dynamic software architecture based on spatial logic
The requirement for modifying system structure during system execution is specified by dynamic software architectures. The system architecture style should remain one style or transform within a scope so that some constraints need to be imposed on during the system execution. Our work expands such an idea along two directions in the setting of formalism. The first direction is to model the system by a graph-based calculus stressing the structure. The other direction lies in that we tailor spatial logic to be a suitable logic as the system specification for structure. The model and specification are basis for the model checking algorithm that is to verify whether the system evolution satisfies some structure constraints. We invite a master-slave architecture style as a running example from the beginning and throughout the paper to demonstrate our approach. Such work can be seen as the basis of the structure analysis for architectures.
4863
On Finite Alphabets and Infinite Bases II: Completed and Ready Simulation
We prove that the equational theory of the process algebra BCCSP modulo completed simulation equivalence does not have a finite basis. Furhermore, we prove that with a finite alphabet of actions, the equational theory of BCCSP modulo ready simulation equivalence does not have a finite basis. In contrast, with an infinite alphabet, the latter equational theory does have a finite basis.
2913360
Dynamic verification of temporal constraints on-the-fly for workflow systems
Temporal verification is an important method to check the temporal correctness of workflow management systems (WfMSs). However, the current temporal verification is relatively independent of the workflow system environments. It does not pay sufficient attention to the interrelationship between the temporal verification at different stages, the mutual dependency between some temporal constraints, and the run-time checkpoint selection strategy, which hence hinders the incorporation and consistency between the temporal verification and the workflow system environments. In this paper, we effectively integrate the temporal verification at different stages and explore the dependency between some temporal constraints. In addition, we present a new effective runtime checkpoint selection strategy which dynamically selects appropriate checkpoints based on the activity completion duration. Furthermore, based on these analyses, we develop some new methods for more efficient temporal verification. These analyses and new methods help to eliminate the gap between the temporal verification and the workflow system environments.
14180342
On Some Properties of the Optimally Refined Proportional Sampling Strategy
The optimally refined proportional sampling strategy has been recommended as a better alternative to random testing, when dividing the input domain into equal-sized partitions is easy. This paper investigates some properties of the optimally refined proportional sampling strategy. This investigation provides some useful information on how well the optimally refined proportional sampling strategy outperforms random testing.
41663574
Mining Frequent Tree-Like Patterns in Large Datasets
In this paper, we propose a novel data mining scheme to explore the frequent hierarchical structure patterns, named tree-like patterns, with the relationship of each item on a sequence. By tree-like patterns, we are clear to find out the relation of items between the cause and effect. Finally, we discuss the different characteristics to our mined patterns with others. As a consequence, we can find out that our addressed tree-like patterns can be widely used to explore a variety of different applications.
53305092
Algorithms for Identifying Protein Cross-Links via Tandem Mass Spectrometry
Cross-linking technology combined with tandem mass spectrometry (MS-MS) is a powerful method that provides a rapid solution to the discovery of protein-protein interactions and protein structures. We studied the problem of detecting cross-linked peptides and cross-linked amino acids from tandem mass spectral data. Our method consists of two steps: the first step finds two protein subsequences whose mass sum equals a given mass measured from the mass spectrometry; and the second step finds the best cross-linked amino acids in these two peptide sequences that are optimally correlated to a given tandem mass spectrum. We designed fast and space-efficient algorithms for these two steps and implemented and tested them on experimental data of cross-linked hemoglobin proteins. An interchain cross-link between two beta subunits was found in two tandem mass spectra. The length of the cross-linker (7.7 A) is very close to the actual distance (8.18 A) obtained from the molecular structure in PDB.
43913114
Second-generation error concealment for video transport over error-prone channels
Video transport over error-prone channels may result in loss or erroneous decoding of the video data. Error concealment is an effective mechanism to reconstruct the video data. In this paper, we review error-concealment methods and introduce a new framework, which we refer to as second-generation error concealment. All the error-concealment methods reconstruct the lost video data by making use of certain a priori knowledge about the video content. First-generation error concealment builds such a priori in a heuristic manner. The proposed second-generation error concealment builds the a priori by modeling the statistics of the video content explicitly, typically in the region of interest (ROI). Context-based models are trained with the correctly received video data and then used to replenish the lost video data. Trained models capture the statistics of the video content and thus reconstruct the lost video data better than reconstruction by heuristics. A new dynamic model ‘updating principal components’ (UPC) is proposed as a model for second-generation error concealment. UPC can be applied to pixel values to conceal loss of pixel data. In addition, UPC can be applied to motion vectors, which results in ‘updating eigenflows’ (U-Eigenflow), to conceal loss of motion vectors. With UPC applied to both pixel values and motion vectors, hybrid temporal/spatial error concealment can be achieved. The proposed second-generation error-concealment method provides superior performances to first-generation error-concealment methods. Copyright © 2002 John Wiley & Sons, Ltd.