18785
NCL: A common language for achieving rule-based interoperability among heterogeneous systems
For achieving interoperability among heterogeneous computing systems, the Object Management Group (OMG) has adapted the Common Object Request Broker Architecture (CORBA) and the use of an Interface Definition Language (IDL) for specifying object properties and operations which encapsulate the data and programs of heterogeneous systems. This paper describes a common language which is an enhancement of IDL to include: 1) the semantic richness of EXPRESS, an information modeling language adapted by the ISO/STEP community for achieving product model and data exchange; and 2) the extensibility features and knowledge rule specification offered by the Object-oriented Semantic Association Model (OSAM*). This common language, named the NIIIP Common Language (NCL), is a part of the R&D effort of a project entitled the National Industrial Information Infrastructure Protocols (NIIIP). The design of NCL is standards-based, incorporating the semantic features of the two standard languages, IDL and EXPRESS, and conforming to their syntaxes as much as possible. It is an extensible language which supports the addition of new class, constraint, and association types to the language and its underlying object model in order to satisfy the diverse modeling needs of virtual enterprises. The language also contains a high-level rule specification component. Rules in NCL can be used for defining and enforcing integrity and security constraints, government or enterprise policies and regulations, and other types of semantic constraints that are local or global to heterogeneous systems. In this paper, we shall show how such a modeling language and its supporting KBMS functions can be used to achieve rule-based interoperability in an active heterogeneous system as an enhancement to OMG's CORBA.
6278910
Eyes alive
For an animated human face model to appear natural it should produce eye movements consistent with human ocular behavior. During face-to-face conversational interactions, eyes exhibit conversational turn-taking and agent thought processes through gaze direction, saccades, and scan patterns. We have implemented an eye movement model based on empirical models of saccades and statistical models of eye-tracking data. Face animations using stationary eyes, eyes with random saccades only, and eyes with statistically derived saccades are compared, to evaluate whether they appear natural and effective while communicating.
6168624
Optimizing the Order of Taxon Addition in Phylogenetic Tree Construction Using Genetic Algorithm
Phylogenetics has gained in public favor for the analysis of DNA sequence data as molecular biology has advanced. Among a number of algorithms for phylogenetics, the fastDNAml is considered to have reasonable computational cost and performance. However, it has a defect that its performance is likely to be significantly affected by the order of taxon addition. In this paper, we propose a genetic algorithm for optimizing the order of taxon addition in the fastDNAml. Experimental results show that the fastDNAml with the optimized order of taxon addition constructs more probable evolutionary trees in terms of the maximum likelihood.
33132157
Updatability in Federated Database Systems
It is important to support updates in federated database systems. However, not all updates on the federated schema are possible because some may violate certain constraints in the local databases which are involved in the federation. In this paper, we give a formal framework which characterizes the conditions under which a federated schema object type is updatable. We study the steps involved to systematically map an update request on an external view of a federated schema into the equivalent update(s) on the local databases. We also consider the situation where semantically equivalent object types may not model exactly the same set of objects in the real world. We ensure that the set constraints (EQUAL, SUBSET, DISJOINT) between the instance sets of equivalent object types are not violated after an update.
15400882
Distributed and scalable XML document processing architecture for E-commerce systems
XML has became a very important emerging standard for E-commerce because of its flexibility and universality. Many software designers are actively developing new systems to handle information in XML formats. We propose a generic architecture for processing XML. We have designed an XML processing system using the latest technologies, such as XML, XSLT (XML Stylesheet Language Transformation), HTTP and Java servlets. Our design is very generic, flexible, scalable, extensible, and also suitable for distributed network environments. A main application of the architecture and the system is to support data exchange in E-commerce systems.
819318
Feature Sensitive Out-of-Core Chartification of Large Polygonal Meshes
Mesh chartification is an important tool for processing meshes in various applications. In this paper, we present a novel feature sensitive mesh chartification technique that can handle huge meshes with limited main memory. Our technique adapts the mesh chartification approach using Lloyd-Max quantization to out-of-core processing. While the previous approach updates chartification globally at each iteration of Lloyd-Max quantization, we propose a local update algorithm where only a part of the chartification is processed at a time. By repeating the local updates, we can obtain a chartification of a huge mesh that cannot fit into the main memory. We verify the accuracy of the serialized local updates by comparing the results with the global update approach. We demonstrate that our technique can successfully process huge meshes for applications, such as mesh compression, shape approximation, and remeshing.
14063599
Light field morphing using 2D features
We present a 2D feature-based technique for morphing 3D objects represented by light fields. Existing light field morphing methods require the user to specify corresponding 3D feature elements to guide morph computation. Since slight errors in 3D specification can lead to significant morphing artifacts, we propose a scheme based on 2D feature elements that is less sensitive to imprecise marking of features. First, 2D features are specified by the user in a number of key views in the source and target light fields. Then the two light fields are warped view by view as guided by the corresponding 2D features. Finally, the two warped light fields are blended together to yield the desired light field morph. Two key issues in light field morphing are feature specification and warping of light field rays. For feature specification, we introduce a user interface for delineating 2D features in key views of a light field, which are automatically interpolated to other views. For ray warping, we describe a 2D technique that accounts for visibility changes and present a comparison to the ideal morphing of light fields. Light field morphing based on 2D features makes it simple to incorporate previous image morphing techniques such as nonuniform blending, as well as to morph between an image and a light field.