7412637
EXEC: An Evolvable and eXtensible Environment for Collaboration
This paper presents an evolvable and extensible environment for collaboration (EXEC), which aims to address the long-identified flexibility and reusability issues in collaborative systems. Due to the clean separation between data and control, both user interface components (data) and coordination service components (control) can be reused for developing collaborative applications and be flexibly bound at run time to address the evolutionary needs of collaboration tasks. Additionally, new collaboration tools can be easily prototyped to extend the functionality of the environment
6337639
Transparent sharing and interoperation of heterogeneous single-user applications
Multi-user applications generally lag behind in features or compatibility with single-user applications. As a result, users are often not motivated to abandon their favorite single-user applications for groupware features that are less frequently used. A well-accepted approach, collaboration transparency, is able to convert off-the-shelf single-user applications into groupware without modifying the source code. However, existing systems have been largely striving to develop generic application-sharing mechanisms and undesirably force users to share the same application in cooperative work. In this paper we analyze this problem and present a novel approach (called intelligent collaboration transparency) to addressing this problem. Our approach allows for heterogeneous application sharing by considering the particular semantics of the applications and the collaboration task in question.
37096144
Operation Propagation in Real-Time Group Editors
Operation propagation refers to the mechanisms and policies used in group editors for the participants to notify each other of their individual editing activities. The timing and granularity of propagation depend on different requirements, such as network bandwidth, session scale, the computational power of the involved sites and the preferences of each user. In this article, we draw on some common design principles in two group editors we have implemented.
1850331
COCA: collaborative objects coordination architecture
Coordination policies vary from collaboration to collaboration and are even subject to evolution in different phases of the same collaboration. It is vital for collaborative systems to be flexible enough to accommodate changes to the coordination policies du ring development and the lifetime of the collaboration. Motivated by previous work of separating coordinati on and computation, we propose COCA as a generic framework for developing collaborative systems and modeling the coordination policies. Participants ex plicitly adopt roles, and coordination policies are specifie d in terms of roles in a logic-based specification langu age. Policies are interpreted at runtime at each collabo r ti n site by a COCA virtual machine. It is easy to chang e the coordination policies both during development and a t runtime.
8785272
A Framework for Building Collaboration Tools by Leveraging Industrial Components
Groupware applications allow a distributed group of human users to work apart together over a computer network They are difficult to develop due to the needs to suit a range of collaboration tasks that are often with diverse and evolutionary requirements To address this problem, we propose a new framework in which shared data components conforming to a well-defined interface can be dynamically plugged in for flexible sharing, and a simple transformation tool is provided such that the myriad of industrial collaboration-transparent components can be transformed into shared components The validity of our framework is evaluated by building a suite of typical collaboration tools such as group editors Under our framework, most components in the Java Development Kit (JDK) can be transformed automatically for prototyping collaboration tools With minimal manual work, those tools can be adapted to achieve advanced flexibility, e.g., data and control components can be bound dynamically to switch control protocols.
17075751
A collaboration specification language
COCA (Collaborative Objects Coordination Architecture) was proposed as a novel means to model and support collaborations over the Internet. Our approach separates coordination policies from user interfaces and the policies are specified in a logic-based language. Over the past year, both the collaboration model and the specification language have been substantially refined and evaluated through our experience in building real-life collaboration systems. This paper presents the design of the specification language and illustrates the main ideas with a few simple design examples. Semantics, implementation, runtime support, and applications are also covered but not as the focus of this paper.
1387834
An Efficient Algorithm for Pattern Discovery in Large Text Databases
15275424
Blur identification based on kurtosis minimization
In this paper, we describe an algorithm for identifying a parametrically described blur based on kurtosis minimization. Using different choices for the parameters of the blur, the noisy blurred image is restored using Wiener filter. We use the kurtosis as a measurement of the quality of the restored image. From the set of the candidate deblurred images, the one with the minimum kurtosis is selected. The proposed technique is tested in a simulated experiment on a variety of blurs including atmospheric turbulence blurs, Gaussian blurs, and out-of-focus blurs. The proposed approach is also tested on real blurred images. Moreover, we test the performance when a wrong blur model is given. Our experiments show that the kurtosis minimization measurements match well with methods that maximize PSNR.
6720899
Mode selection and mode-dependency modeling for power-aware embedded systems
Among the techniques for system-level power management, it is not currently possible to guarantee timing constraints and have a comprehensive system model supporting multiple components at the same time. We propose a new method for modeling and selecting the power modes for the optimal system-power management of embedded systems under timing and power constraints. First, we not only model the modes and the transitions overhead at the component level, but we also capture the application-imposed relationships among the components by introducing a mode dependency graph at the system level. Second, we propose a mode selection technique, which determines when and how to change mode in these components such that the whole system can meet all power and timing constraints. Our constraint-driven approach is a critical feature for exploring power/performance tradeoffs in power-aware embedded systems. We demonstrate the application of our techniques to a low-power sensor and an autonomous rover.
7454095
On the relationship between the integer and continuous solutions of convex programs
Abstract A bound is obtained in this note for the distance between the integer and real solutions to convex quadratic programs. This bound is a function of the condition number of the Hessian matrix. We further extend this proximity result to convex programs and mixed-integer convex programs. We also show that this bound is achievable in certain situations and the distance between the integer and continuous minimizers may tend to infinity.
4669631
A new hierarchical control scheme for a class of cyclically repeated discrete-event systems
We extend the hierarchical control method in (Li et al., 2004) to a more generic setting which involves cyclically repeated processes. A hierarchical architecture is presented to facilitate control synthesis. Specifically, a conservative max-plus model for cyclically repeated processes is introduced on the upper level which provides an optimal online plan list. An enhanced min-plus algebra based scheme on the lower level not only handles unexpected events but, more importantly, addresses cooperation issues between sub-plants and different cycles. A rail traffic example is given to demonstrate the effectiveness of the proposed approach.