Joseph B. Kopena

DAMLJessKB: a tool for reasoning with the Semantic Web

Fully realizing the Semantic Web vision will require practical tools. We believe that DAMLJessKB is one such tool. As more and more Web sites, network services, databases, and knowledge bases look to DAML as a de facto representation syntax, we hope that DAMLJessKB will become one in a suite of tools that let users truly leverage the shared semantics.

Mobile robot labs

There has been much interest in achieving educational and research objectives through the use of small, low-cost robot platforms. While our initial experiences with these platforms were similarly positive, we questioned whether these platforms could be pushed beyond their early uses and transitioned towards achieving substantial educational and research goals. This article reports initial results of this investigation - the construction and implementation of a series of detailed lab assignments using these platforms to tackle basic computer science, AI, robotics, and engineering problems. We first provide detailed descriptions of the labs we have developed and then discuss the robot platforms, including the progression of hardware issues encountered. Finally, we share what we have learned from this endeavor.

Semantic integration through invariants

A semantics-preserving exchange of information between two software applications requires mappings between logically equivalent concepts in the ontology of each application. The challenge of semantic integration is therefore equivalent to the problem of generating such mappings, determining that they are correct, and providing a vehicle for executing the mappings, thus translating terms from one ontology into another. This article presents an approach toward this goal using techniques that exploit the model-theoretic structures underlying ontologies. With these as inputs, semi-automated and automated components may be used to create mappings between ontologies and perform translations.

DAMLJessKB: a tool for reasoning with the semantic web

We describe DAMLJessKB, a tool for reasoning with the DARPA Agent Markup Language (DAML) and performing inference on the Semantic Web. DAMLJessKB maps DAMLs semantics into facts and rules for use in a production system, such as the Java Expert System Shell (Jess). This article presents our underlying methodology and provides a detailed example of how DAMLJessKB can be used to make decisions about DAML-encoded engineering design knowledge. We believe that tools like DAMLJessKB are needed to help realize the full potential of the Semantic Web and DAML.

Development and Specification of a Reference Model for Agent-Based Systems

Agent-based systems have been the object of intense research over the past decade. While great theoretical progress has been made, the software frameworks for creating agent-based systems offer considerable variability in their capabilities and functionality. This paper introduces a reference model for agent-based systems. The purpose of a reference model is to provide a common conceptual basis for comparing systems and driving the development of software architectures and other standards. The Foundation for Intelligent Physical Agents and other groups have advanced a number of agent standards, yet, to date, no comprehensive reference model has been presented for software systems composed of agents. This paper provides an overview of a reference model for agent-based systems. The agent systems reference model is the result of a multiyear effort studying software systems built with agents and software frameworks for implementing these systems. As part of this study, the team applied software reverse engineering techniques to perform static and dynamic analysis of operational agent-based systems. This analysis enabled identification of key common concepts across over one dozen different agent frameworks. To demonstrate its applicability, the reference model is then used to analyze a number of complete agent-based software systems. It is the belief of the authors that the reference model will be an essential prerequisite for future transition, deployment, and integration of agent-based systems.

Service-based computing on manets: enabling dynamic interoperability of first responders

Mobile ad hoc networks will form a critical part of the first-responder communications infrastructure. Empirical data shows how network-aware, autonomous, mobile agents can manage information services on live manet environments. A multidisciplinary team in Drexel Universitys College of Engineering has been working with local law enforcement and transportation officials to identify problems in enabling police, fire, security, and other public protectors to effectively communicate and collaborate in first-response situations. Development of the Philadelphia Area Urban Wireless Network Testbed (PA-UWNT) is part of this effort. The PA-UWNT is a mobile ad hoc network (manet) comprising mobile computers (PDAs, tablets, and laptops) and Web service-based applications. Our experience in the PA-UWNT project indicates that constructing such systems will require new research developments in computer networking, agent and service-based computing, and security that integrate each of these disciplines at several fundamental levels. In this paper, we outline part of this approach through experiments demonstrating the utility of integrating the network and agent layers and enabling agents to reason about the current operating context. We posit that autonomous agents that can reason about the networks slate and services offer an effective means of meeting the manet environments challenges.

Distributed Coordination of First Responders

In a disaster scenario, first responders must be able to perform multiple functions in a coordinated way. At all levels of the task - from integrating heterogeneous systems to addressing response tasks and allocating resources - responders must be able to make decisions in a globally optimal fashion. Automated coordination mechanisms can help, but they still face several challenges that researchers must address to make them effective and useful. This article discusses the application of distributed constraint optimization in disaster management coordination.

On the long-term retention of geometry-centric digital engineering artifacts

This paper discusses the challenges of long-term preservation of digital geometric models and the engineering processes associated with them. For engineering, design, manufacturing, and physics-based simulation data this requires formats that are accessible potentially indefinitely into the future. One of the fundamental challenges is the development of digital geometry-centric engineering representations that are self describing and assured to be interpretable over the long lifespans required by archival applications. Additionally, future users may have needs that require other information, going beyond geometry, be also accessible to fully interpret the model. These problems are highly interdisciplinary and not exclusively algorithmic or technical. To provide context, the paper introduces a case study illustrating an overall portrait of the problem. Based on observations from this case study, we present a framework for enhancing the preservation of geometry-centric engineering knowledge. This framework is currently being used on a number of projects in engineering education.

OntoNet: Scalable knowledge-based networking

Recent years have seen a proliferation of work on the Semantic Web, an initiative to enable intelligent agents to reason about and utilize World Wide Web content and services. Concurrently, the networking community has developed a concept of the knowledge plane, using artificial intelligence to reason about and manage network behavior. These two efforts have progressed independently despite potential synergies. This paper presents early work on OntoNet, a knowledge-based middleware which aims to integrate those visions and provide flexible, scalable knowledge-based networking with ontologies. We focus on supporting multicast messaging in mobile ad-hoc networks using description logic advertisements and requests in a subset of the Web Ontology Language (OWL). We explore a novel hybrid tree- mesh protocol which enables efficient and robust propagation of potentially verbose queries and descriptions. We demonstrate the potential viability of this protocol via simulations in the newly developed NS-3 simulator.

RapidMesh: declarative toolkit for rapid experimentation of wireless mesh networks

We present the RapidMesh toolkit for rapid protocol simulation, implementation and experimentation of wireless mesh networks. RapidMesh utilizes declarative networking, a declarative, database-inspired extensible infrastructure that uses query languages to specify behavior. RapidMesh integrates a declarative networking engine with the emerging ns-3 network simulator. The same declarative specifications can also be used as actual implementations using the ns-3 network emulator, hence providing a bridge between simulation and testbed-based experimentation. We demonstrate that RapidMesh enables a variety of wireless routing protocols and neighbor discovery protocols can be synthesized via compact declarative specifications. We experimentally validate declarative MANET routing protocols in dynamic settings within RapidMesh operating in ns-3 simulation environment and on the ORBIT wireless testbed.