19558398
Gestures for Embodied Agents with Logic Programming
The paper discusses how distributed logic programming can be used to define and control the hand gestures of embodied agents in virtual worlds, by using the STEP language as an interface between the constructs of logic programming and the humanoid model defined in Virtual Reality Modelling Language (VRML). By using this framework, different gesture dictionaries can be defined and variants of a hand gesture, according to dynamically changing factors, can be generated on the fly. The approach is tested on the demanding demonstrator of conducting, providing experience, also on time performance of the animation.
17536375
Interactive Agents Learning Their Environment
In this paper we describe the implementation of interactive agents capable of gathering and extending their knowledge. Interactive agents are designed to perform tasks requested by a user in natural language. Using simple sentences the agent can answer questions and in case a task can not be fulfilled the agent must communicate with the user. In particular, an interactive agent can tell when necessary information for a task is missing, giving the user a chance to supply this information, which may in effect result in teaching the agent. The interactive agent platform is implemented in DLP, a tool for the implementation of 3D web agents. In this paper we discuss the motivation for interactive agents, the learning mechanisms and it’s realization in the DLP platform.
607902
A Framework for Handling Inconsistency in Changing Ontologies
One of the major problems of large scale, distributed and evolving ontologies is the potential introduction of inconsistencies. In this paper we survey four different approaches to handling inconsistency in DL-based ontologies: consistent ontology evolution, repairing inconsistencies, reasoning in the presence of inconsistencies and multi-version reasoning. We present a common formal basis for all of them, and use this common basis to compare these approaches. We discuss the different requirements for each of these methods, the conditions under which each of them is applicable, the knowledge requirements of the various methods, and the different usage scenarios to which they would apply.
7369101
Trust and Commitment in Dynamic Logic
Trust and commitment have been identified as crucial concepts in electronic commerce applications. In this paper we are interested in the relation between these social concepts. We introduce a dynamic logic in which violations of stronger commitments result in a higher loss of trustworthiness than violations of weaker ones. We illustrate how the logic can be used to analyze some aspects of a well known example of trust within reason.
1230191
3D agent-based virtual communities
In this paper we propose an approach to 3D agent-based virtual communities in which autonomous agents are participants in VRML-based virtual worlds to enhance the interaction with users or serve as intelligent navigation assistants. In addition, an agent communication language (ACL) is designed as a high-level communication facility, in particular for the realization of shared objects in virtual communities. As a typical example of 3D agent-based virtual communities, a VRML-based multi-user soccer game has been developed and implemented in the distributed logic programming language DLP. We discuss how DLP can be used for the implementation of 3D agent-based virtual communities.
14014109
Dynamic Goal Hierarchies
In this paper we introduce and formalise dynamic goal hierarchies. We begin with a formal definition of goals, according to which they are rational desires. In particular, we require that an agent's goals are coherent; that is, that the agent believes that each goal is jointly realisable with all of the goals which the agent considers to be more important. Thus an agent's goals form a hierarchy, and new goals are defined with reference to it. We then show how preferential entailment can be used to formalise the rational revision of goals and goal hierarchies.
1348972
Non-photorealistic rendering and content-based image retrieval
In this paper, we will show how non-photorealistic rendering (NPR) can take a new role in content-based image retrieval (CBIR). The proposed CBIR method applies a novel image similarity measure: unlike traditional features like color, texture, or shape, our measure is based on a painted representation of the original image. This is produced by a stochastic paintbrush algorithm which simulates a painting process. We use the stroke parameters (color, size, orientation, and location) as features and similarity is measured by matching strokes of a pair of images. The advantage of our approach is that it provides information not only about the color content but also about the structural properties of an image without the segmentation of the image. Experimental results show that the CBIR method using paintbrush features has higher retrieval rate than traditional methods using color or texture features only.
607595
The HUMANOID Environment for Interactive Animation of Multiple Deformable Human Characters
We describe the HUMANOID environment dedicated to human modeling and animation for general multimedia, VR, and CAD applications integrating virtual humans. We present the design of the system and the integration of the various features: generic modeling of a large class of entities with the BODY data structure, realistic skin deformation for body and hands, facial animation, collision detection, integrated motion control and parallelization of computation intensive tasks.
14317741
Interactive 3D modeling using only one image
For virtual reality systems, modeling of 3D objects and scenes is important and challenging. In this paper, we present an image-based interactive 3D modeling framework consisting of three major modules: photogrammetric modeling, human interaction, and texture mapping. These three modules are not sequentially used and they are mixed in the whole modeling process. The major idea is to explore the use of images in interactive modeling systems to achieve the automation. In particular, the use of only one image is addressed. On one side, unlike the common fully interactive modeling framework, the users are not required to specify some low level details interactively which can be derived automatically from the image. On the other side, it still requires human interactions to do some high level tasks that the algorithms are difficult to perform automatically. We have implemented the framework and experimental results are good.
33359596
A framework to customize a face model for reusing animation
We propose a framework to customize a face model for reusing animation. In this framework, two orthogonal photos of a human face are used as input. Based on them, a set of feature points is manually selected. Then, the existing face model will be adapted for both the geometry and muscle model underneath. We formulate it as a nonlinear optimization problem and apply the Levenberg-Marquardt method for the solution. We can get the result instantly. The result is a new animation-ready model with the same look as the two photos. Applying the previous motion specification to this model, we can reuse the animation. Our initial results demonstrate that our approach is effective.
456837
Dynamic buffer management with extensible replacement policies
The objective of extensible DBMSs is to ease the construction of specialized DBMSs for nontraditional applications. Although much work has been done in providing various levels of extensibility (e.g., extensibility of data types and operators, query language extensibility, and query optimizer extensibility), there has been very limited research in providing extensibility at the buffer management level. Supporting extensibility at the buffer management level is important as it can contribute significantly to overall system performance.This paper addresses the problem of supporting extensibility of buffer replacement policies. The main contribution is the proposal of a framework for modeling buffer replacement policies. This work is novel in two aspects. First, by providing a uniform and generic specification of buffer replacement policies, the proposed framework unifies existing work in this area. Second, our work introduces a new level of extensibility. None of the existing extensible DBMSs, to our knowledge, provides extensibility at the buffer management level. The proposed framework provides a basis for the construction of an extensible buffer manager as part of a 100% Java-based storage manager. We conducted an extensive performance study to investigate the performance of the proposed framework. The experimental results demonstrate that the proposed framework is indeed feasible for existing DBMSs and improves system performance significantly without costing significant overhead.