Center of Excellence in Command, Control, Communications, and Intelligence
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The Center of Excellence in Command, Control, Communications, and Intelligence at George Mason University was established under the direction of Dr.Harry Van Trees in July 1989 in order to provide an intellectual base for the command , control, communications, and intelligence area. Dr.Mark Pullen, who became the Center's Director in 2005, has continued its emphasis on bringing academic expertise to the needs of the U.S. military and related government and commercial applications of information technology. The Center conducts a broad spectrum R&D and educational program in C4I. The program is accomplished by bringing together a multidisciplinary group consisting of academic faculty, research staff, and fellows in residence from industry and government.
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Browsing Center of Excellence in Command, Control, Communications, and Intelligence by Author "Costa, Paulo C. G."
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Item A Proposal for a W3C XG on Uncertainty Reasoning for the World Wide Web(Information Extraction & Transport, Inc. (IET), 2006-11) Laskey, Kenneth J.; Costa, Paulo C. G.; Laskey, Kathryn B.The Semantic Web envisions effortless cooperation between humans and computers, seamless interoperability and information exchange among web applications, and rapid and accurate identification and invocation of appropriate Web services. At the current stage of evolution in Semantic Web research, there is a growing understanding that a major step towards this vision involves the implementation of principled uncertainty representation and reasoning in SW applications. This position paper introduces initial thoughts on how the World Wide Web Consortium (W3C) Incubator XG process could be employed to move forward the concept of a Web with uncertainty.Item Bayesian ontologies in AI systems(2006-07-30T03:10:44Z) Costa, Paulo C. G.; Laskey, Kathryn B.; AlGhamdi, GhaziOntologies have become ubiquitous in current-generation information systems. An ontology is an explicit, formal representation of the entities and relationships that can exist in a domain of application. Following a well-trodden path, initial research in computational ontology has neglected uncertainty, developing almost exclusively within the framework of classical logic. As appreciation grows of the limitations of ontology formalisms that cannot represent uncertainty, the demand from user communities increases for ontology formalisms with the power to express uncertainty. Support for uncertainty is essential for interoperability, knowledge sharing, and knowledge reuse. Bayesian ontologies are used to describe knowledge about a domain with its associated uncertainty in a principled, structured, sharable, and machine-understandable way. This paper considers Multi-Entity Bayesian Networks (MEBN) as a logical basis for Bayesian ontologies, and describes PR-OWL, a MEBN-based probabilistic extension to the ontology language OWL. To illustrate the potentialities of Bayesian probabilistic ontologies in the development of AI systems, we present a case study in information security, in which ontology development played a key role.Item Bayesian Semantics for the Semantic Web(George Mason University, 2005-07-12) Costa, Paulo C. G.Uncertainty is ubiquitous. Any representation scheme intended to model real-world actions and processes must be able to cope with the effects of uncertain phenomena. A major shortcoming of existing Semantic Web technologies is their inability to represent and reason about uncertainty in a sound and principled manner. This not only hinders the realization of the original vision for the Semantic Web (Berners-Lee & Fischetti, 2000), but also raises an unnecessary barrier to the development of new, powerful features for general knowledge applications. The overall goal of our research is to establish a Bayesian framework for probabilistic ontologies, providing a basis for plausible reasoning services in the Semantic Web. As an initial effort towards this broad objective, this dissertation introduces a probabilistic extension to the Web ontology language OWL, thereby creating a crucial enabling technology for the development of probabilistic ontologies. The extended language, PR-OWL (pronounced as “prowl”), adds new definitions to current OWL while retaining backward compatibility with its base language. Thus, OWL-built legacy ontologies will be able to interoperate with newly developed probabilistic ontologies. PR-OWL moves beyond deterministic classical logic (Frege, 1879; Peirce, 1885), having its formal semantics based on MEBN probabilistic logic (Laskey, 2005). By providing a means of modeling uncertainty in ontologies, PR-OWL will serve as a supporting tool for many applications that can benefit from probabilistic inference within an ontology language, thus representing an important step toward the World Wide Web Consortium’s (W3C) vision for the Semantic Web. In addition, PR-OWL will be suitable for a broad range of applications, which includes improvements to current ontology solutions (i.e. by providing proper support for modeling uncertain phenomena) and much-improved versions of probabilistic expert systems currently in use in a variety of domains (e.g. medical, intelligence, military, etc).Item DTB Project: A Behavioral Model for Detecting Insider Threats(MITRE Corporation, 2005-05) Costa, Paulo C. G.; Laskey, Kathryn B.; AlGhamdi, Ghazi; Barbará, Daniel; Shackelford, Thomas; Mirza, Sepideh; Revankar, MehulThis paper describes the Detection of Threat Behavior (DTB) project, a joint effort being conducted by George Mason University (GMU) and Information Extraction and Transport, Inc. (IET). DTB uses novel approaches for detecting insiders in tightly controlled computing environments. Innovations include a distributed system of dynamically generated document-centric intelligent agents for document control, object oriented hybrid logic-based and probabilistic modeling to characterize and detect illicit insider behaviors, and automated data collection and data mining of the operational environment to continually learn and update the underlying statistical and probabilistic nature of characteristic behaviors. To evaluate the DTB concept, we are conducting a human subjects experiment, which we will also include in our discussion.Item MEBN Logic: A Key Enabler for Network Centric Warfare(CCRP Publications, 2005-06) Costa, Paulo C. G.; Laskey, Kathryn B.; Takikawa, Masami; Pool, Michael; Fung, Francis; Wright, Edward J.Among the lessons learned from recent conflicts stands the dramatic change in the very way wars are fought. There are no more clear-cut enemies or allies; rules of engagement have become increasingly fuzzy; guerrilla and insurgent tactics are now commonplace: in short, the battlespace is a very different place from what it used to be. Furthermore, advances in sensor technology and network computing have brought a new element to the complex equation of warfare: information overload. Nowadays, instead of merely gathering information and displaying assets, command and control systems must be able to fill the gap between the glut of information arriving from a networked grid of sensors and the capacity of human commanders to make sense of it. In short, the quest today is for systems that work under the knowledge paradigm. Systems must automatically provide decision makers with a clear picture of what is happening, how it relates to the current situation, and what are the options and their respective consequences. Facing this challenge with technologies of the past is a recipe for failure. New, more powerful approaches are needed. The objective of this paper is to argue for two claims: (1) Bayesian decision theory is an appropriate technology for modeling human decision-making in complex, ambiguous scenarios; and (2) Bayesian reasoning technology is a promising enabler for Network Centric Warfare. To support both claims, we have applied Multi-Entity Bayesian Networks (MEBN) to model a historical tactical decision from the naval domain. MEBN is a breakthrough Bayesian reasoning system in which complex probabilistic models are constructed from modular components that can be replicated and combined in an infinite variety of ways. MEBN allows models to capture important and subtle aspects of objects and their interrelationships that would be impossible to model using existing technologies. We provide a brief overview of modeling in MEBN and then present our model and the outcome of applying it to a historical scenario. Our results clearly support the validity of our approach.Item Multi-Entity Bayesian Networks without Multi-Tears(2006-01-27T23:47:24Z) Costa, Paulo C. G.; Laskey, Kathryn B.An introduction is provided to Multi-Entity Bayesian Networks (MEBN), a logic system that integrates First Order Logic (FOL) with Bayesian probability theory. MEBN extends ordinary Bayesian networks to allow representation of graphical models with repeated sub-structures. Knowledge is encoded as a collection of Bayesian network fragments (MFrags) that can be instantiated and combined to form highly complex situation-specific Bayesian networks. A MEBN theory (MTheory) implicitly represents a joint probability distribution over possibly unbounded numbers of hypotheses, and uses Bayesian learning to refine a knowledge base as observations accrue. MEBN provides a logical foundation for the emerging collection of highly expressive probability-based languages. A running example illustrates the representation and reasoning power of the MEBN formalism.Item Of Starships and Klingons: Bayesian Logic for the 23rd Century(AUAI Press, 2005-07) Laskey, Kathryn B.; Costa, Paulo C. G.Intelligent systems in an open world must reason about many interacting entities related to each other in diverse ways and having uncertain features and relationships. Traditional probabilistic languages lack the expressive power to handle relational domains, whereas classical first-order logic is sufficiently expressive but lacks a coherent plausible reasoning capability. Recent years have seen the emergence of a variety of approaches to integrating first-order logic, probability, and machine learning. This paper presents Multi-entity Bayesian networks (MEBN), a formal system that integrates First Order Logic (FOL) with Bayesian probability theory. MEBN extends ordinary Bayesian networks to allow representation of graphical models with repeated sub-structures. We present the logic using an example inspired by the Paramount Series Star Trek. MEBN semantics integrates random variables as formalized in mathematical statistics with model theoretic semantics for first-order logic.Item PR-OWL: A Bayesian Framework for the Semantic Web(2005-11-07) Costa, Paulo C. G.; Laskey, Kathryn B.; Laskey, Kenneth J.This paper addresses a major weakness of current technologies for the Semantic Web, namely the lack of a principled means to represent and reason about uncertainty. This not only hinders the realization of the original vision for the Semantic Web, but also creates a barrier to the development of new, powerful features for general knowledge applications that require proper treatment of uncertain phenomena. We propose to extend OWL, the ontology language recommended by the World Wide Web Consortium (W3C), to provide the ability to express probabilistic knowledge. The new language, PR-OWL, will allow legacy ontologies to interoperate with newly developed probabilistic ontologies. PR-OWL will move beyond the current limitations of deterministic classical logic to a full first-order probabilistic logic. By providing a principled means of modeling uncertainty in ontologies, PR-OWL will serve as a supporting tool for many applications that can benefit from probabilistic inference within an ontology language, thus representing an important step toward the W3C’s vision for the Semantic Web.Item Probabilistic Ontologies for Efficient Resource Sharing in Semantic Web Services(Information Extraction & Transport, Inc. (IET), 2006-11) Costa, Paulo C. G.; Laskey, Kathryn B.; Laskey, Kenneth J.Service Oriented Architecture (SOA) is a key technology to support interoperability among data and processing resources. Semantic interoperability requires mapping between vocabularies of independently developed resources, a task fraught with uncertainty. Probabilistic ontologies enable representation of knowledge in domains characterized by uncertainty. As such, they promise to improve the quality of service descriptions, enable more thorough analysis of service composition opportunities, and provide a theoretically sound methodology for semantic mapping under uncertainty. This paper defines probabilistic ontologies, discusses their application to SOA, and presents a conceptual scheme for using a federation of ontologies (with both common and probabilistic ontologies) as a semantic mapping tool for service oriented information exchange systems with different levels of service descriptions (including legacy and probabilistic enabled descriptions).