1358360
A Web service for efficient ontology comparison
In this paper, we develop a Web service for ontology comparison based on a novel senses refinement algorithm, which builds senses sets to represent the semantics of the input ontologies. The senses refinement algorithm converts the measurement of ontology difference into simple set operations based on set theory, thus ensures the efficiency and accuracy of the ontology comparison. We believe our Web service is the first available online measurement tool for ontology comparison.
54104798
Data allocation algorithms for distributed video servers
42282919
Exploring Local Community Structures in Large Networks
In this paper, we extend the concept of degree from single vertex to sub-graph, and present a formal definition of module/community in a network based on this extension. A new locally optimized algorithm is designed to find the module for a given source vertex in a network. Our analysis shows that the complexity of this algorithm is O(K2d), where K is the number of vertices to be explored in the sub-graph and d is the average degree of the vertices in the sub-graph. Based on this algorithm, we implement a JAVA tool, MoNet, for exploring local community structures in large networks. Using this tool to analyze a co-purchase network from Amazon shows that there are local community structures in this network. Further analyses on these local community structures demonstrate that media items are much easier to form compact local modules than book items do, indicating that recommending digital media items to customers based on co-purchasing information in the online store will be more efficient than recommending books.
14997765
2PSM: an efficient framework for searching video information in a limited-bandwidth environment
Abstract. We present a novel technique, called 2-Phase Service Model, for streaming videos to home users in a limited-bandwidth environment. This scheme first delivers some number of non-adjacent data fragments to the client in Phase 1. The missing fragments are then transmitted in Phase 2 as the client is playing back the video. This approach offers many benefits. The isochronous bandwidth required for Phase 2 can be controlled within the capability of the transport medium. The data fragments received during Phase 1 can be used to provide an excellent preview of the video. They can also be used to facilitate VCR-style operations such as fast-forward and fast-reverse. Systems designed based on this method are less expensive because the fast-forward and fast-reverse versions of the video files are no longer needed. Eliminating these files also improves system performance because mapping between the regular files and their fast-forward and fast-reverse versions is no longer part of the VCR operations. Furthermore, since each client machine handles its own VCR-style interaction, this technique is very scalable. We provide simulation results to show that 2-Phase Service Model is able to handle VCR functions efficiently. We also implement a video player called {\em FRVplayer}. With this prototype, we are able to judge that the visual quality of the previews and VCR-style operations is excellent. These features are essential to many important applications. We discuss the application of FRVplayer in the design of a video management system, called VideoCenter. This system is intended for Internet applications such as digital video libraries.
7304743
Proxy ecology - cooperative proxies with artificial life
In this paper, we propose a novel P2P cooperative proxy cache system using an individual-based model. We borrow the idea from an ecological system as well as economic systems to manage the cooperative proxies through data and information exchange among individual proxies. The data flow among proxy nodes creates artificial life for the cooperative proxies. The proxy servers with artificial life can automatically configure themselves into a virtual proxy graph. The aggregate effect of caching actions by individual peer proxies automatically distributes the Web document closer to the clients and balances the workload. Our simulation results show that the proposed proxy caching scheme tremendously improves the system performance. In addition, the individual-based design model ensures the simplicity and scalability of the cache system.
9138036
Earthworm: a network memory management technique for large-scale distributed multimedia applications
The two main operating constraints of today's multimedia servers are the I/O bandwidth and communication bandwidth limitations. Both of these problems are addressed in this paper using a novel technique called Earthworm. In this scheme, the network memory is used as a huge cache for buffering multimedia data. Dramatic reduction in the demand on the I/O bandwidth, therefore, can be achieved. This scheme also chains display stations to allow them to forward video streams. This strategy eliminates the congestion at the communication port of the server. Removing this bottleneck allows our technique to operate on the vast aggregate bandwidth of the WAN rather than being constrained by the very limited local bandwidth available to the server. A unique feature of the Earthworm approach is that every display station using the server attempts to make some contribution to the caching space and communication bandwidth. The arrival of a new request, therefore, can be seen as a contributor, rather than just a burden to the server. This characteristic ensures the scalability of our design to support very large multimedia applications.
8736717
Skew detection and reconstruction based on maximization of variance of transition-counts
Abstract The input document images with skew can be a serious problem in the optical character recognition system. A robust method is proposed in this paper for skew detection and reconstruction in document images which can contain less text areas, high noises, tables, figures, flow-chart, and photos. The basic idea of our approach is the maximization of variance of transition counts for the skew detection and text-orientation determination. Once the skew angle is determined, the scanning-line model is applied to reconstruct the skew images. 103 documents with great varieties have been tested and successfully processed. The average detection time of A4 size image is 4.86 s and the reconstruction time is 5.52 s. The proposed approach is also compared with the existing algorithms published in the literature and our method gets some significant improvements in skew detection and reconstruction.
53249335
Modeling and rendering of quasi-homogeneous materials
Many translucent materials consist of evenly-distributed heterogeneous elements which produce a complex appearance under different lighting and viewing directions. For these quasi-homogeneous materials, existing techniques do not address how to acquire their material representations from physical samples in a way that allows arbitrary geometry models to be rendered with these materials. We propose a model for such materials that can be readily acquired from physical samples. This material model can be applied to geometric models of arbitrary shapes, and the resulting objects can be efficiently rendered without expensive subsurface light transport simulation. In developing a material model with these attributes, we capitalize on a key observation about the subsurface scattering characteristics of quasi-homogeneous materials at different scales. Locally, the non-uniformity of these materials leads to inhomogeneous subsurface scattering. For subsurface scattering on a global scale, we show that a lengthy photon path through an even distribution of heterogeneous elements statistically resembles scattering in a homogeneous medium. This observation allows us to represent and measure the global light transport within quasi-homogeneous materials as well as the transfer of light into and out of a material volume through surface mesostructures. We demonstrate our technique with results for several challenging materials that exhibit sophisticated appearance features such as transmission of back illumination through surface mesostructures.
2328843
Data-rich section extraction from HTML pages
We propose a novel algorithm, DSE (data-rich subtree extraction) to recognize and extract the data-rich section of an HTML page. We apply the DSE algorithm as a pre-processing "clean-up" step for two typical Web information retrieval problems: topic distillation and Web information extraction. Our experiments show that, for the test data sets used, the DSE algorithm can correctly identify data-rich sections of HTML pages with 100% accuracy. Therefore, it can effectively reduce the root set size for the topic distillation problem thereby improving the precision and accuracy of the IETS algorithm. Furthermore, when applied to the Web information extraction problem using the IEPAD algorithm, it can decrease the number of patterns discovered by this algorithm, thus shortening its time cost to generalize a wrapper for HTML pages.
16940978
Video tooning
We describe a system for transforming an input video into a highly abstracted, spatio-temporally coherent cartoon animation with a range of styles. To achieve this, we treat video as a space-time volume of image data. We have developed an anisotropic kernel mean shift technique to segment the video data into contiguous volumes. These provide a simple cartoon style in themselves, but more importantly provide the capability to semi-automatically rotoscope semantically meaningful regions.In our system, the user simply outlines objects on keyframes. A mean shift guided interpolation algorithm is then employed to create three dimensional semantic regions by interpolation between the keyframes, while maintaining smooth trajectories along the time dimension. These regions provide the basis for creating smooth two dimensional edge sheets and stroke sheets embedded within the spatio-temporal video volume. The regions, edge sheets, and stroke sheets are rendered by slicing them at particular times. A variety of styles of rendering are shown. The temporal coherence provided by the smoothed semantic regions and sheets results in a temporally consistent non-photorealistic appearance.
30210949
Exact and approximate algorithms for unordered tree matching
We consider the problem of comparison between unordered trees, i.e., trees for which the order among siblings is unimportant. The criterion for comparison is the distance as measured by a weighted sum of the costs of deletion, insertion and relabel operations on tree nodes. Such comparisons may contribute to pattern recognition efforts in any field (e.g., genetics) where data can naturally be characterized by unordered trees. In companion work, we have shown this problem to be NP-complete. This paper presents an efficient enumerative algorithm and several heuristics leading to approximate solutions. The algorithms are based on probabilistic hill climbing and bipartite matching techniques. The paper evaluates the accuracy and time efficiency of the heuristics by applying them to a set of trees transformed from industrial parts based on a previously proposed morphological model. >