8194176
AMOEBA-RT: Run-Time Verification of Adaptive Software
Increasingly, software must dynamically adapt its behavior in response to changes in the supporting computing, communication infrastructure, and in the surrounding physical environment. Assurance that the adaptive software correctly satisfies its requirements is crucial if the software is to be used in high assurance systems, such as command and control or critical infrastructure protection systems. Adaptive software development for these systems must be grounded upon formalism and rigorous software engineering methodology to gain assurance. In this paper, we briefly describe AMOebA-RT , a run-time monitoring and verification technique that provides assurance that dynamically adaptive software satisfies its requirements.
2702943
Specifying real-time properties in autonomic systems
Increasingly, computer software must adapt dynamically to changing conditions. The correctness of adaptation cannot be rigorously addressed without precisely specifying the requirements for adaptation. In many situations, these requirements involve absolute time, in addition to a logical ordering of events. This paper introduces an approach to formally specifying such timing requirements for adaptive software. We introduce TA-LTL, a timed adaptation-based extension to linear temporal logic, and use this logic to specify three timing properties associated with the adaptation process: safety, liveness, and stability. A dynamic adaptation scenario involving interactive audio streaming software is used to illustrate the timed temporal logic.
21312091
Optimizing the Java Piped I/O Stream Library for Performance
The overall performance of Java programs has been significantly improved since Java emerged as a mainstream programming language. However, these improvements have revealed a second tier of performance bottlenecks. In this paper, we address one of these issues: the performance of Java piped I/O stream library. We analyze commonly used data transfer patterns in which one reader thread and one writer thread communicate via Java piped I/O streams. We consider data buffering and synchronization between these two threads, as well as the thread scheduling policy used in the Java virtual machine. Based on our observations, we propose several optimization techniques that can significantly improve Java piped I/O stream performance. We use these techniques to modify the Java piped I/O stream library. We present performance results for seven example programs from the literature that use the Java piped I/O stream library. Our methods improve the performance of the programs by over a factor of 4 on average, and by a factor of 27 in the best case.
13958128
Towards Re-engineering Legacy Systems for Assured Dynamic Adaptation
Increasingly, software must adapt its behavior in response to changes in the supporting computing, communication infrastructure, and in the surrounding physical environment. Since most existing software was not designed to adapt, research on technique to make legacy software dynamically adaptive has gained increasing interest. Assurance is crucial for adaptive software to fulfill its intended purpose. Correctness is even more critical if it is to be applied in high assurance systems. This paper proposes a model-driven approach to introduce dynamic adaptation to non-adaptive legacy systems while maintaining assurance properties. An aspect-oriented technique is applied to achieve separation of concerns in the implementation.
38325345
Specifying adaptation semantics
Computer software must dynamically adapt to changing conditions. In order to fully realize the benefit of dynamic adaptation, it must be performed correctly. The correctness of adaptation cannot be properly addressed without precisely specifying the requirements for adaptation. This paper introduces an approach to formally specifying adaptation requirements in temporal logic. We introduce A-LTL, an adaptation-based extension to linear temporal logic, and use this logic to specify three commonly used adaptation semantics. Neighborhood composition and sequential composition techniques are developed and applied to A-LTL to construct the specification of an adaptive system. We introduce adaptation semantics graphs to visually present the adaptation semantics. Specifications for adaptive systems can be automatically generated from adaptation semantics graphs.
207159067
Model-based development of dynamically adaptive software
Increasingly, software should dynamically adapt its behavior at run-time in response to changing conditions in the supporting computing and communication infrastructure, and in the surrounding physical environment. In order for an adaptive program to be trusted, it is important to have mechanisms to ensure that the program functions correctly during and after adaptations. Adaptive programs are generally more difficult to specify, verify, and validate due to their high complexity. Particularly, when involving multi-threaded adaptations, the program behavior is the result of the collaborative behavior of multiple threads and software components. This paper introduces an approach to create formal models for the behavior of adaptive programs. Our approach separates the adaptation behavior and non-adaptive behavior specifications of adaptive programs, making the models easier to specify and more amenable to automated analysis and visual inspection. We introduce a process to construct adaptation models, automatically generate adaptive programs from the models, and verify and validate the models. We illustrate our approach through the development of an adaptive GSM-oriented audio streaming protocol for a mobile computing application.
13353635
Research group on digital government in North America: developing a comparative and transnational agenda
This poster describes the second year's progress of the research group on Comparative and Transnational Digital Government in North America. This group was formed in 2007 to advance electronic government research across geographic and political boundaries in the region, with the support of the National Science Foundation Digital Government Research Program and the home institutions of the members in Canada, Mexico, and the United States. During the second year of activities, the group members joined their expertise and interests in two face-to-face meetings in Canada. During the second year of work, group members advanced research proposals and developed preliminary products on two topical areas as well as a first draft of a Research Agenda for North America. The group members will continue the discussion of this research agenda in Cholula, Mexico as part of the activities of the 10th Annual International Conference on Digital Government Research (dg.o 2009).
15742108
Supporting software evolution through model-driven program transformation
Model-Driven Software Development (MDSD) techniques are being adopted with more frequency in the engineering of computer based systems, especially in the area of distributed real-time embedded (DRE) systems. This brief summary presents two research objectives for supporting software evolution in MDSD. First, the concept of model-driven program transformation is introduced to support evolution of large legacy software systems. The second research objective that is presented involves the application of a mature program transformation engine to automate model interpreter evolution in the presence of meta-model schema changes.
14759570
Simplifying the Reconstruction of 3D Models using Parameter Elimination
Reconstructing large models from images is a significant challenge for computer vision, computer graphics, and related fields. In this paper, we present an approach for simplifying the reconstruction process by mathematically eliminating external camera parameters. This results in less parameters to estimate and in an overall significantly more robust and accurate reconstruction. We reformulate the problem in such a manner as to be able to identify invariants, eliminate superfluous parameters, and measure the performance of our formulation under various conditions. We compare a two-step camera orientation-free method, where the majority of the points are reconstructed using a linear equation set, and a camera position-and- orientation free method, using a degree-two equation set. Both approaches use a full perspective camera and are applied to synthetic and real-world datasets.
39806803
Model-Driven Adaptive Self-healing for Autonomic Computing
Self-healing is a vital property that an autonomic system must possess in order to provide robust performance and survivability. The promise of self-healing depends on other properties that the system should provide, which include self-monitoring and self-configuring. Autonomic systems further require self-healing behavior to adapt to changes in user needs, business goals, and environmental conditions such that self-healing decisions are made dynamically and adaptively according to the system context. In this paper, we propose a model-driven approach that leverages modeling techniques, reliability engineering methodologies, and aspect-oriented development to realize an adaptive self- healing paradigm for autonomic computing.
25014721
Motion segmentation of multiple translating objects from line correspondences
This paper presents an analytic approach to motion segmentation of multiple translating objects from line correspondences in three perspective views. The basic idea of our algorithm is to view the estimation of multiple translational motions as the estimation of a single, though more complex, multibody motion model that is then factored into the original models by polynomial differentiation. Experimental results on synthetic and real scenes are presented.