15632441
Direction-Adaptive Discrete Wavelet Transform via Directional Lifting and Bandeletization
We propose an adaptive lifted discrete wavelet transform to locally adapt the filtering direction to the geometric flow in the image. The proposed approach refines previous directional lifting approaches to achieve superior compression performance with less demand for computation. Additionally, a bandeletization procedure is combined with directional lifting in a unified framework to further remove the correlation in the wavelet coefficients. Up to 2.8 dB improvement in PSNR over the conventional 2-D CDF 9/7 wavelet transform for natural images is reported. Significant improvement in subjective quality is also observed.
1786671
Light field compression using disparity-compensated lifting and shape adaptation
We propose disparity-compensated lifting for wavelet compression of light fields. With this approach, we obtain the benefits of wavelet coding, such as scalability in all dimensions, as well as superior compression performance. Additionally, the proposed approach solves the irreversibility limitations of previous light field wavelet coding approaches, using the lifting structure. Our scheme incorporates disparity compensation into the lifting structure for the transform across the views in the light field data set. Another transform is performed to exploit the coherence among neighboring pixels, followed by a modified SPIHT coder and rate-distortion optimized bitstream assembly. A view-sequencing algorithm is developed to organize the views for encoding. For light fields of an object, we propose to use shape adaptation to improve the compression efficiency and visual quality of the images. The necessary shape information is efficiently coded based on prediction from the existing geometry model. Experimental results show that the proposed scheme exhibits superior compression performance over existing light field compression techniques.
12151320
Mining Periodic Patterns in Sequence Data
Periodic pattern mining is the problem that regards temporal regularity. There are many emerging applications in periodic pattern mining, including web usage recommendation, weather prediction, computer networks and biological data. In this paper, we propose a Progressive Timelist-Based Verification (PTV) method to the mining of periodic patterns from a sequence of event sets. The parameter min_rep, is employed to specify the minimum number of repetitions required for a valid segment of non-disrupted pattern occurrences. We also describe a partitioning approach to handle extra large/long data sequence. The experiments demonstrate good performance and scalability with large frequent patterns.
15614662
Towards increasing web application productivity
In this paper we present and discuss a template/meta-data based partial code generation system supporting web application development. Seamlessly incorporating the recent top-notch technologies, the framework maximally exploits the capabilities of the underlying implementation technologies. Our approach primarily benefits the framework and code developers. In addition, the complete separation of data model, navigation model, and presentation model reflects on a more general conceptual process that would decouple the technique and methodology from its underlying technology choices. The decoupling between the generated code and the code that is necessarily added later on through other development pathways than the generator deals with the incremental changes and adaptations of the models in the face of an operational system, therefore further enhances the extensibility, maintainability, and reusability of the generated applications.
18643244
An Empirical Performance Study on PSIM
It is well known that errors caught in the early stages of system development life cycle greatly helped reduce the expense for later error fixing and mitigate risks and complications. Performance analysis is one of the methods to ensure satisfactory system performance that can avoid redesign and patch in the later stage of system development when performance problems emerge. Much work has been done to address such concerns collectively known as the 'performance engineering' problem. However, a comprehensive method is still needed to provide an end-to-end support for performance evaluation on software architecture design. Automated tools to support the method must be developed, and its validation must be carefully planned and conducted. In response to this need, we propose our approach, PSIM (performance simulation and modeling). PSIM is a performance simulation and modeling tool that integrated performance properties into software architecture specifications expressed in several major UML diagrams. PSIM models can be transformed into Colored GSPN (colored generalized stochastic Petri nets) via an automated tool. As a result, the Colored GSPN models can be simulated to perform model-based performance evaluation. In this paper PSIM is first briefly reviewed and illustrated through modeling a web-based electronic conferencing system, called M-Net, to derive performance metrics. We then conduct runtime performance testing to the implementation of M-Net and compare the simulation results against the runtime testing data. PSIM is shown to be effective in predicting system performance and in identifying system performance bottlenecks through this experimentation.
11608556
MORF: A Distributed Multimodal Information Filtering System
The proliferation of objectionable information on the Internet has reached a level of serious concern. To empower end-users with the choice of blocking undesirable and offensive Web-sites, we propose a multimodal personalized information filter, named MORF. The design of MORF aims to meet three major performance goals: efficiency, accuracy, and personalization. To achieve these design goals, we have devised a multimodality classification algorithm and a personalization algorithm. Empirical study and initial statistics collected from the MORF filters deployed at sites in the U.S. and Asia show that MORF is both efficient and effective, compared to the traditional URL- and text-based filtering approaches.
2500932
Mediating electronic meetings
Electronic meeting control has been the focus of many research efforts; however, extensively adopted standards are still unavailable. In this paper, we present a generic model for electronic meeting control. Our model is based on the formal meeting protocol commonly known as the parliamentary procedure or Robert's Rules of Order (RRO). Capturing the essential features of traditional RRO, we suggest extension mechanisms in order to exploit the capabilities of electronic media. Centered on the concept of a discussion thread, our extended RRO model can handle concurrent meeting activities, multiple floors, amendment nesting, and discussion hierarchies. M-Net, an electronic meeting system, is introduced as an example supported by our model.