26576594
OminiSearch: a method for searching dynamic content on the Web
To address the search problem over dynamic web pages, several domain-speci c information integration portal services have emerged, such as jango.excite.com and cnet.com. These integration services o er uniform access to heterogeneous collections of dynamic pages using wrapper technology. Common techniques used for constructing wrapper programs often require embedding programmers' understanding of the speci c presentation layout or speci c contents of the Web pages, often with the assistance of semi-automatic tools. However, even with partially automated tools, developing and maintaining wrappers turns out to be labor intensive and error-prone, especially for Web sites that are frequently changing their information presence on the Web. As a result, most information integration services are limited to a handful of sources and have a limited capability to e ectively incorporate additional or updated content providers into their existing integration access framework. The OminiSearch system demonstrates a method to incorporate new dynamic sources into an integration system in which useful data objects are extracted from dynamic Web pages without programmer intervention, and to maintain the capability to extract relevant information in the face of evolving structure in the Web sites.
599285
Differential evaluation of continual queries
We define continual queries as a useful tool for monitoring of updated information. Continual queries are standing queries that monitor the source data and notify the users whenever new data matches the query. In addition to periodic refresh, continual queries include Epsilon Transaction concepts to allow users to specify query refresh based on the magnitude of updates. To support efficient processing of continual queries, we propose a differential re-evaluation algorithm (DRA), which exploits the structure and information contained in both the query expressions and the database update operations. The DRA design can be seen as a synthesis of previous research on differential files, incremental view maintenance, and active databases.
3582970
Building a Semantic Web System for Scientific Applications: An Engineering Approach
This paper presents an engineering experience for building a Semantic Web compliant system for a scientific application – agricultural zoning. First, we define the concept of ontological cover and a set of relationships between such covers. These definitions, based on domain ontologies, can be used, for example, to support the discovery of services on the Web. Second, we propose a semantic acyclic restriction on ontologies which enables the efficient comparison of ontological covers. Third, we present different engineering solutions to build ontology views satisfying the acyclic restriction in a prototype. Our experimental results unveil some limitations of the current Semantic Web technology to handle large data volumes, and show that the combination of such technology with traditional data management techniques is an effective way to achieve highly functional and scalable solutions.
33902172
An Object-Centered Approach for Manipulating Hierarchically Complex Objects
We present an object-centered approach for manipulating hierarchically complex objects, which covers an extended object model and an object-centered query algebra. Extensions of the object model are mainly based on a separation of structural and semantic elements in modeling complex objects, including a general distinction between aggregation reference and association reference, an introduction of type inheritance into aggregation hierarchies and a support for combination of aggregation inheritance with subtype inheritance. Based on the extensions, we develop a query algebra as an integral part of the model. Unlike most of existing algebra-based query languages, our object algebra takes complex object collectively as a unit of high level queries and allows complex objects to be accessed at all levels of aggregation hierarchies without having resort to any kind of path expressions. Features of aggregation hierarchies, such as acyclicity and aggregation inheritance, have played important roles in such a development. We have also formally described the output type of each operator in order for dynamic classification of query results in the IsA type/class lattice. Although the design is based on the chosen object-oriented model, other object-oriented databases are possible. We feel that the proposal largely covers the query requirements for complex objects, and meanwhile provides users with an opportunity to remain within the framework of the model of complex objects while querying database. As a consequence, the flexibility and adaptability of the object-oriented model against schema changes are increased.
12589406
VISTA: Validating and Refining Clusters Via Visualization
Clustering is an important technique for understanding of large multidimensional datasets. Most of clustering research to date has been focused on developing automatic clustering algorithms and cluster validation methods. The automatic algorithms are known to work well in dealing with clusters of regular shapes, for example, compact spherical shapes, but may incur higher error rates when dealing with arbitrarily shaped clusters. Although some efforts have been devoted to addressing the problem of skewed datasets, the problem of handling clusters with irregular shapes is still in its infancy, especially in terms of dimensionality of the datasets and the precision of the clustering results considered. Not surprisingly, the statistical indices works ineffective in validating clusters of irregular shapes, too. In this paper, we address the problem of clustering and validating arbitrarily shaped clusters with a visual framework (VISTA). The main idea of the VISTA approach is to capitalize on the power of visualization and interactive feedbacks to encourage domain experts to participate in the clustering revision and clustering validation process. The VISTA system has two unique features. First, it implements a linear and reliable visualization model to interactively visualize multi-dimensional datasets in a 2D star-coordinate space. Second, it provides a rich set of user-friendly interactive rendering operations, allowing users to validate and refine the cluster structure based on their visual experience as well as their domain knowledge.
9143242
Update Monitoring: The CQ Project
In rapidly growing open environments such as the Internet, users experience information starvation in the midst of data overload, due to difficulties similar to finding the needle in a haystack. Update monitoring is a promising area of research where we bring the right information to the user at the right time, instead of forcing the user through manual browsing or repeated submission of queries. As an example of update monitoring research, we outline our work in the Continual Queries (CQ) project, including its basic concepts, software architecture, and current implementation status.
32876579
Medical image segmentation and retrieval via deformable models
A new method based on deformable shape models for medical image segmentation is described. Experiments for blood cell micrographs have been conducted to verify the accuracy of the shape model-based segmentation and object shape description method. The cell segmentation method does not require user input for initialization. Coherence information between cells is utilized via a globally consistent cost function. The proposed segmentation method can be used in automated analysis for images of stained blood smear and segmentation of other medical structures. A method for shape population-based retrieval is also described. Results of population-based image queries for a database of blood cell micrographs are shown.
24019518
Obtaining the service language for H.245's multimedia capability exchange signalling protocol: the final step
The capability exchange signalling (CES) protocol is a subprotocol of ITU-T recommendation H.245, "control protocol for multimedia communication". We are interested in verifying this protocol, including verification of its general properties such as absence of deadlocks and livelocks, and verification of the protocol against its service. In previous work, we have analysed the general properties of the CES protocol. In order to verify the protocol against its service, we need to generate the CES service language, which defines all the possible sequences of user observable events. We firstly create the CES service CPN model and then extract the language from the occurrence graph (OG) of the model. In the case of the CES service, this is challenging because we wish to have a general result for arbitrary capacity of the network over which the CES protocol operates. To tackle this problem we introduced into the CPN model a parameter, l, representing the capacity of the communication channel. We derived a recursive formula for the parameterised OG in terms of l. We treat this OG as a finite state automaton (FSA) by nominating acceptance states and apply FSA reduction algorithms to obtain a deterministic FSA that represents the CES service language. We have discovered a recursive formula in l for the CES service language. This paper introduces the CES service via its CPN model as necessary background and presents the final step of the proof of this finding.
34700716
Local computation of Gaussian belief functions
12537942
Deformable shape detection and description via model-based region grouping
A method for deformable shape detection and recognition is described. Deformable shape templates are used to partition the image into a globally consistent interpretation, determined in part by the minimum description length principle. Statistical shape models enforce the prior probabilities on global, parametric deformations for each object class. Once trained, the system autonomously segments deformed shapes from the background, while not merging them with adjacent objects or shadows. The formulation can be used to group image regions based on any image homogeneity predicate; e.g., texture, color or motion. The recovered shape models can be used directly in object recognition. Experiments with color imagery are reported.
3249877
Dual Laplacian editing for meshes
Recently, differential information as local intrinsic feature descriptors has been used for mesh editing. Given certain user input as constraints, a deformed mesh is reconstructed by minimizing the changes in the differential information. Since the differential information is encoded in a global coordinate system, it must somehow be transformed to fit the orientations of details in the deformed surface, otherwise distortion will appear. We observe that visually pleasing deformed meshes should preserve both local parameterization and geometry details. We propose to encode these two types of information in the dual mesh domain due to the simplicity of the neighborhood structure of dual mesh vertices. Both sets of information are nondirectional and nonlinearly dependent on the vertex positions. Thus, we present a novel editing framework that iteratively updates both the primal vertex positions and the dual Laplacian coordinates to progressively reduce distortion in parametrization and geometry. Unlike previous related work, our method can produce visually pleasing deformations with simple user interaction, requiring only the handle positions, not local frames at the handles.