Peter Weinstein - Academia.edu (original) (raw)

Papers by Peter Weinstein

Ann Arbor, 2007

The quantity and complexity of information on the Web is growing rapidly. While several simple in... more The quantity and complexity of information on the Web is growing rapidly. While several simple interactive search tools exist to help locate items of interest on the Web, the increasing sophistication of uses and the sheer quantity of data together indicate a need ...

Ontologies are more than a particularly elaborate approach to the description and classification ... more Ontologies are more than a particularly elaborate approach to the description and classification of information. They can be used to support the operation and growth of a new kind of digital library, implemented as a distributed, intelligent system. We describe the design and use of ontologies in the University of Michigan Digital Library. These ontologies will model all aspects of the digital library, including content, services, and licenses. We have refined and extended the IFLA hierarchy for the realization of work, and are starting to use ontologies to support reasoning about content search. We have also used the ontologies to classify the capabilities of computational elements of the system (agents), in a dynamic way that sustains functionality as new agents are added to the system. 1 1 Introduction We are developing ontologies of digital library content, services, and licenses, to support the evolution of distributed, intelligent information systems. Ontologies are highly exp...

Abstract. One of our goals when building the University of Michigan Digital Library (UMDL) has be... more Abstract. One of our goals when building the University of Michigan Digital Library (UMDL) has been to prototype an architecture that can continually recon gure itself as users, contents, and services come and go. We haveworked toward this goal by developing a multi-agent infrastructure with agents that buy and sell services from each other using our commerce and communication protocols. We refer to the services and protocols o ered by this infrastructure as the Service Market Society (SMS). Within the SMS, agents are able to nd, work with, and even try to outsmart each other, as each agent attempts to accomplish the tasks for which itwas created. When we open the door to decentralized decision-making among self-interested agents, there is a risk that the system will degenerate into chaos. In this paper, we describe the protocols, services, and agent abilities embedded in the SMS infrastructure that combat such chaos while permitting exibility, extensibility, and scalability of the ...

To anticipate and prevent acts of terrorism, Indications and Warnings analysts try to connect clu... more To anticipate and prevent acts of terrorism, Indications and Warnings analysts try to connect clues gleaned from massive quantities of complex data. Multi-agent approaches to support Indications and Warnings are appropriate because ownership and security issues fragment the data. Furthermore, the massive scale of the data suggests the need for large numbers of agents. The Ant CAFE...

The Service Classifier Agent maintains a dynamic ontology of agent capabilities. To advertise the... more The Service Classifier Agent maintains a dynamic ontology of agent capabilities. To advertise their services, agents define concepts at runtime. These concepts are automatically classified with description logic. Agents requesting services can select the best available to meet their needs, using queries that exploit rich knowledge about services and their relations to other services. Runtime classification of agent services encourages the development of agents to provide new services. New agents may be utilized immediately upon joining a society, without requiring modification or even notification of existing agents. 1.

Abstract. Information processing operations in support of intelligence analysis are of two kinds.... more Abstract. Information processing operations in support of intelligence analysis are of two kinds. They may sift relevant data from a larger body, thus reducing its quantity, or sort that data, thus reducing its entropy. These two classes of operation typically alternate with one another, successively shrinking and organizing the available data to make it more accessible and understandable. We term the resulting construct, the “semantic pyramid. ” We sketch the general structure of this construct, and illustrate two adjacent layers of it that we have implemented in the Ant CAFÉ. 1.

Concepts in differentiated ontologies inherit definitional structure from concepts in shared onto... more Concepts in differentiated ontologies inherit definitional structure from concepts in shared ontologies. Shared, inherited structure provides a common ground that supports measures of “description compatibility.” These algorithms are the primary contribution of this paper. The description-compatibility measures compare concepts to predict semantic compatibility, the probability that an instance of a recommendation will satisfy a request. The description-compatibility measures cross a spectrum regarding their knowledge of the semantics of roles in concept definitions. Some of the measures identify and analyze correspondences among elements of the definitions, and are thus a form of analogical reasoning. We use simulations to evaluate the description-compatibility measures in detail. Description compatibility can be used to rank alternative query translations, and to guide search for capabilities across communities that subscribe to differentiated ontologies.

The paper describes a novel approach to cognitive architecture exploration in which multiple cogn... more The paper describes a novel approach to cognitive architecture exploration in which multiple cognitive architectures are integrated in their entirety. The goal is to increase significantly the application breadth and utility of cognitive architectures generally. The resulting architecture favors a breadth-first rather than depth-first approach to cognitive modeling by focusing on matching the broad power of human cognition rather than any specific data set. It uses human cognition as a functional blueprint for meeting the requirements for general intelligence. For example, a chief design principle is inspired by the power of human perception and memory to reduce the effective complexity of problem solving. Such complexity reduction is reflected in an emphasis on integrating subsymbolic and statistical mechanisms with symbolic ones. The architecture realizes a “cognitive pyramid” in which the scale and complexity of a problem is successively reduced via three computational layers: Pr...

To enable decentralized development of large societies of agents, agents should be able to select... more To enable decentralized development of large societies of agents, agents should be able to selectively team with others based on declarative descriptions of services, rather than a priori knowledge. This capability is difficult to achieve because descriptions written by different developers may be terminologically heterogenous— including vocabulary from ontologies that are potentially inconsistent. For example, one agent might describe its service as (a formal equivalent of) “query planning for high-school biology”, while another agent wants to “find collections for advanced life sciences”. We want the latter agent to recognize that the former might satisfy its request. We have completed research on two aspects of this problem. Our Service Classifier Agent (SCA) supports selection of agent services in societies that are dynamic and evolving, but whose agents all use the same ontologies [Weinstein and Birmingham 97]. We have also developed an algorithm that identifies maximal similar...

This paper presents a vision for an internet application that will support constructive political... more This paper presents a vision for an internet application that will support constructive political discourse. Consensus Builder will invite people to speak their beliefs and engage in interpretive processes that result in internal representation of statements as ontological models. Analyses of similarities and differences between statements will support listening and exchange of ideas. Semantically informed query and summarization capabilities will facilitate learning from Consensus Builder and the emergence of community leaders capable of negotiating solutions to difficult problems. Illustrations of interfaces for each aspect of Consensus Builder help the reader to understand what using Consensus Builder will be like, and to appreciate its potential contribution to society.

Consensus Builder is a vision for an internet application that can organize and facilitate politi... more Consensus Builder is a vision for an internet application that can organize and facilitate political discussion involving large numbers of participants. Consensus Builder will invite people to speak about what they know and care about. To fully participate, speakers will need to engage in interpretive processes that yield ontological models of statements like those used for the Semantic Web. Analyses of similarities and differences between statements will support listening and exchange of ideas. Semantically informed query and summarization capabilities will aggregate and publish speaker beliefs and facilitate learning from Consensus Builder. One potential early focus for Consensus Builder would be to support a badly needed national discussion about health care. Applications from the organizational to the global levels are also possible.

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We are developing techniques for unifying models of business processes that span and integrate or... more We are developing techniques for unifying models of business processes that span and integrate organizations. In this paper, we describe our approach and discuss its potential for broader application to decision-making and political process. Key elements of the approach include the following. Participants work with familiar diagrams that the system represents internally in OWL. The system unifies models of analogous processes in a manner where users contribute confirmation and guidance but are not required to provide any particular input. Unified models can be compared, yielding visualizations that crystallize insight and metrics for quantifying alignment. The unification process thus identifies commonality and analyzes differences. This process is therefore well suited to facilitate thorough discussion of policy issues in a manner that fosters creative negotiation and consensus building.

The Business Process Interoperability Living Ontologies (BPILO) project is developing tools for c... more The Business Process Interoperability Living Ontologies (BPILO) project is developing tools for comparing models of business processes across multiple organizations. Models are represented on two levels: users work with familiar diagrams, while the system works internally with OWL. A swarming model unification algorithm converts original models expressed in heterogeneous terminology into unified models that maximize terminological and substantive commonality. Users contribute confirmation and guidance to the unification process, but are not required to provide any particular input. Unified models can be compared, yielding visualizations that crystallize insight and metrics that quantify alignment. BPILO can thus provide scientifically rigorous comparisons of business processes. Potential applications include studies focused on integration, conformance, business process reengineering, and process alignment.

We use formal ontologies to represent knowledge about digital-library content and services. Forma... more We use formal ontologies to represent knowledge about digital-library content and services. Formal ontologies define concepts with logic in a frame-inheritance structure. The expressiveness and precision of these structures supports computational reasoning that can be used in important ways. This paper focuses on the creation of ontological metadata. We create ontological content metadata by generating it from MARC (MAchine Readable Cataloging) data. MARC contains much information that is hard to exploit computationally. In particular, relationships between works are implicit in shared values and natural-language notes. The conversion process involves specifying an ontological model, mapping MARC to the ontology, and reasoning about the data to create explicit links between works. Service metadata will be supplied by providers who wish to participate fully in a digital library that is implemented as a decentralized multi-agent system. Agents advertise by describing their services in...

We propose an approach to achieve appropriate exchange of services and data in distributed system... more We propose an approach to achieve appropriate exchange of services and data in distributed systems subject to semantic heterogeneity. We assume differentiated ontologies: that terms have formal definitions as concepts related to other concepts, that local concepts inherit from concepts that are shared, and that most or all primitives are shared. We then develop measures of description compatibility using the structure of the source and target definitions. We evaluate these measures by generating description-logic ontologies in artificial worlds. In our simulations, the "meaning" of a concept is its denotation in a finite universe of instances. The accuracy of the description-compatibility measures can thus be judged by their success in predicting the overlap of concept denotations. Description compatibility can be used to guide agent search for services across communities that subscribe to differentiated ontologies. 2 Differentiated Ontologies To enable calculation of the compatibility measures, we make certain assumptions about the syntactic representation of terms to be mapped. Structures that satisfy these assumptions are differentiated ontologies. Assumption 1: Terms are defined as concepts in formal ontologies. Ontologies are sets of concept definitions. Formal ontologies use logic to define concepts by their relations to other concepts. For example, chair might be defined as a-kind-of furniture that a person can sit-upon. 1 The concept chair denotes the set of objects that are chairs; the instance chair001 denotes a particular chair object. The logic must, like description logic, support computational inference of subsumption (Woods 1991). Concept A subsumes B if and only if every instance of B is always an instance of A. Highchair, for example, might be defined as a-kind-of furniture that a toddler can sit-upon; by comparing the definitions for chair and highchair and person and toddler, respectively, description logic can deduce that highchair is a-kind-of chair. (See Weinstein and Birmingham (Weinstein and Birmingham 1998) for an expanded description of "formal ontology"; in this paper, Section 4 specifies the representation that we use in our simulations.) The structure of ontological definition provides a basis for syntactic comparison. The precision required by logic, and in particular the support for subsumption inference, is required to enable calculation of the compatibility measures. Whereas Assumption 1 is fundamental to our enterprise, the following assumptions are "soft" in that they can be violated, but increasing frequency of violation yields increasingly poor results for our description-compatibility measures. Assumption 2: Concepts inherit definitional structure from concepts that are shared. This assumption identifies the form of commonality that we use to enable automatic mapping. Note that mapping between concepts in differentiated ontologies is equivalent to mapping between concepts in a single ontology that provides separate spaces for concept names. Assumption 3: Primitive concepts and relations are shared. Non-primitive definitions have both necessary and sufficient conditions, but primitives have only necessary conditions. For example, given the primitive (C ⇒ D), we cannot infer that instance j ∈ C unless this is asserted explicitly. Clearly, there can be no basis for matching a primitive element of a concept definition to any element of a concept in an ontology where the primitive is undefined. We expect differentiated ontologies to occur in two important contexts. First, architects may design infrastructures for multi-agent systems that include one or more generic ontologies to which all agents are expected to subscribe. As systems change over time, developers will create local versions of ontologies that are specialized to help meet the needs of particular user communities. Over time, large ontological structures will develop, and communities of agents will be defined by the ontologies they use to communicate. Agents will interact with agents in their own community, but may use the techniques

Ann Arbor, 2007

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