Dean B. Krafft

Core services in the architecture of the national science digital library (NSDL)

We describe the core components of the architecture for the National Science Digital Library (NSDL). Over time the NSDL will include heterogeneous users, content, and services. To accommodate this, a design for a technical and organization infrastructure has been formulated based on the notion of a spectrum of interoperability. This paper describes the first phase of the interoperability infrastructure including the metadata repository, search and discovery services, rights management services, and user interface portal facilities.

A case study of flexible object manipulation

This article describes a project undertaken to explore pro gramming physical operations on complex flexible objects. Uncertainty about the exact state of the object makes it im possible to precisely specify the actions to be performed at the time the program is written. Furthermore, the detailed conse quences of manipulations on flexible objects cannot be deter mined before the action is performed. Lacking precise specifi cations, the programmer must abstract the essential properties of objects and actions. In an effort to study manipulation offlexible objects, a system to tie knots in rope with a robot arm was developed. The system includes an extensible graph representation for knots, a vision system that binds the contour of a physical rope to an abstract description, and a knot-tying language based on parametric motion commands. Knots of modest complexity, such as a bowline or figure 8, can be tied in a va riety of ropes with minimal constraints on the initial configu ration of the rope. The work highlights the importance of software engineering principles and a good programming en vironment for robot program development.

Ncore: architecture and implementation of a flexible, collaborative digital library

NCore is an open source architecture and software platform for creating flexible, collaborative digital libraries. NCore was developed by the National Science Digital Library (NSDL) project, and it serves as the central technical infrastructure for NSDL. NCore consists of a central Fedora-based digital repository, a specific data model, an API, and a set of backend services and frontend tools that create a new model for collaborative, contributory digital libraries. This paper describes NCore, presents and analyzes its architecture, tools and services; and reports on the experience of NSDL in building and operating a major digital library on it over the past year and the experience of the Digital Library for Earth Systems Education in porting their existing digital library and tools to the NCore platform.

Dienst: Building a Production technical Report Server

Dienst is a protocol and implementation that provides Internet access to a distributed, decentralized multi-format document collection. It supports full text and boolean searches, thumbnail visual browsing, onscreen reading, and printing. In this paper we describe a number of issues that arose as we developed Dienst, including copyright policy, document management, and handling multiple formats of documents, and then lay out a number of areas where we still need to make progress, including interoperability among heterogeneous search engines, reliability, logical document structuring, and technology transfer.

Representing contextualized information in the NSDL

The NSDL (National Science Digital Library) is funded by the National Science Foundation to advance science and math education. The initial product was a metadata-based digital library providing search and access to distributed resources. Our recent work recognizes the importance of context – relations, metadata, annotations – for the pedagogical value of a digital library. This new architecture uses Fedora, a tool for representing complex content, data, metadata, web-based services, and semantic relationships, as the basis of an information network overlay (INO). The INO provides an extensible knowledge base for an expanding suite of digital library services.

An information network overlay architecture for the NSDL

We describe the underlying data model and implementation of a new architecture for the National Science Digital Library (NSDL) by the Core Integration Team (CI). The architecture is based on the notion of an information network overlay. This network, implemented as a graph of digital objects in a Fedora repository, allows the representation of multiple information entities and their relationships. The architecture provides the framework for contextualization and reuse of resources, which we argue is essential for the utility of the NSDL as a tool for teaching and learning

Toward better computer science: Dependent on software, the United States needs a national policy on computer-science research: The scientists need more time and money for research, teaching, and leadership

The authors call for a national policy in the US on computer science research. They argue that computer scientists need more time and money for research, teaching, and leadership. The benefits of coordinated research and the consequences of computer failure are illustrated.

NSDL MatDL: adding context to bridge materials e-research and e-education

The National Science Digital Library (NSDL) Materials Digital Library Pathway (MatDL) has implemented an information infrastructure to disseminate government funded research results and to provide content as well as services to support the integration of research and education in materials. This poster describes how we are integrating a digital repository into opensource collaborative tools, such as wikis, to support users in materials research and education as well as interactions between the two areas. A search results plug-in for MediaWiki has been developed to display relevant search results from the MatDL repository in the Soft Matter Wiki established and developed by MatDL and its partners. Collaborative work with the NSDL Core Integration team at Cornell University is also in progress to enable information transfer in the opposite direction, from a wiki to a repository.