Clifford Behrens

A regional analysis of Barí land use intensification and its impact on landscape heterogeneity

Since pacification 30 years ago, the Barí of northwest Venezuela have aggregated in villages and have begun to produce cattle and some crops for sale in regional markets. This research analyzes satellite imagery to compare patterns of land use among Barí settlements that differ in their population size, cattle holdings, and distance to nearest marketplace. These comparisons indicate that settlement history mediates the effect of population pressure and herd sizes on land use. Moreover, intensification of land use is associated with greater deforestation and a more heterogeneous landscape, but less biodiversity in woody species.

Telcordia LSI Engine: implementation and scalability issues

Latent Semantic Indexing (LSI), a vector space-based approach to information retrieval, has been proven to be an effective tool in correlating and retrieving relevant documents. While much work has been published on LSI, most of it addresses the algorithmic or theoretical basis of the model. Little, if any, presents implementation issues in practice. We describe a production-level implementation of LSI. The system integrates components including document collection and preprocessing, singular value decomposition (SVD), multilingual processing, and a tree-based access method for similarity querying. We discuss implementation issues encountered during the development of the system. In particular, we address scalability issues in the query engine and various components of the system, and present lessons learned.

Labor specialization and the formation of markets for food in a Shipibo subsistence economy

Traditionally, the Shipibo economy was subsistence-based with shifting cultivation supplying calories, principally in the form of plantains and root crops, while fishing and hunting provided animal proteins to the diet. Some men, who recently began producing rice for sale in regional markets, now allocate less time to wild food procurement. Moreover, this trend has been accompanied by the nucleation of households, a growing cash market for agricultural labor, and the intravillage sale of faunal foods. This paper shows that with cash cropping, some Shipibo now freely distribute less food to others in relation to the amount they produce. To account for this change, a theory is developed based on time allocation and patterns of economic behavior reported throughout the Amazon. This theory is then applied to explain specialization and the formation of cash markets for food labor among the Shipibo.

Web services for knowledge-driven collaborative modeling

This paper describes new Web services that provide knowledge validation to panels of domain experts involved in the collaborative construction of models. Since 9/11, the intelligence community has moved aggressively to develop new IT infrastructures that make better use of their domain expertise to counter terrorism. While these infrastructures have the potential to improve the quality of intelligence produced by expert panels, use of collaboration tools often lacks sufficient motivation. We are addressing these concerns in our Schemer prototype. This is a DARPA-funded R&D effort to provide new consensus analysis services that process information acquired from human collaborators. Unlike previous approaches that support interactions between experts based on organizational relationships, Schemer leverages knowledge and its distribution among panelists to motivate use of available collaboration tools, i.e., knowledge-driven collaboration. Schemer services have been designed and implemented as a Web service that plays the critical role of a broker between information analysis/modeling tools and collaboration tools.

The Geospatial Interoperability Problem: Lessons Learned from Building the Geolens Prototypye

In 1994 NASA issued a Cooperative Agreement Notice to support new research on digital library technology that would enable broader public use of its Earth science data over the Internet. As a response to this CAN, the Universal Spatial Data Access Consortium (USDAC) was formed and it proposed to prototype the GeoLens system that would not only give broader public access to NASA’s Earth observation data, but also made these data interoperate with other geospatial data served by the Federal government. Part of the challenge of the GeoLens Project has been to decompose the larger geospatial interoperability problem into constituent issues. This chapter will address these issues and describe solutions implemented in our GeoLens prototype. The purpose of this exercise is to support an end-to-end scenario, beginning with geospatial data discovery and ending with conflation of geospatial data extracts from extremely heterogeneous sources. The larger goal is to investigate the opportunity for new information processing standards and innovative digital library technology to play a key role in the realization of this scenario.

Mapping domain expertise within teams: visual stimulation of knowledge-building through collaboration

Recent R&D efforts for the U.S. Intelligence Community have been directed towards providing new information technology that better supports collaborative war-gaming and decision-modeling among expert teams so as to produce valid and reliable intelligence in a more-timely, less-costly manner. This paper describes Schemer, a Web service that provides knowledge validation and collaboration support to virtual panels of experts. Of particular interest is the way that Schemer uses visualization of knowledge distribution among panelists to motivate collaboration, with the goal of fostering greater consensus and knowledge-building, hence, better intelligence. Since an additional requirement for supporting virtual panels is incremental data acquisition from panel members, models must often be computed from incomplete data. The same visualization techniques for evaluating consensus formation and knowledge-building among panelist also prove useful for evaluating the impact of data imputation on model validity and reliability.

Collaborative Panel Administrator: A framework and implementation for expert panel lifecycle management

In this paper, we describe the Collaborative Panel Administrator, a collaboration framework designed to manage the lifecycle of virtual teams of domain experts working in collaborative gaming and modeling. A unique feature of the CPA is the way it is guided by sound experimental research design so that information collected from panelists can be vetted, and knowledge built from this information can be validated quantitatively. The framework is deployed as a J2EE application and provides extension points to integrate critical services needed to foster collaboration among panelists and analyze the information acquired from them. We examine in detail the CPApsilas integration with a commercial collaboration platform.