NASA Scientific and Technical Aerospace Reports
NASA Scientific and Technical Aerospace Reports
NASA Scientific and Technical Aerospace Reports
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
initially began in 1998 under the DARPA Cyber Panel Project, a part of the DARPA Information Assurance <strong>and</strong> Survivability<br />
project. Cyber Panel sought to provide high-level capabilities to help defend mission-critical information systems by<br />
monitoring them for signs of cyber attack <strong>and</strong> allowing operators to manage the operation of system security/survivability<br />
technologies to avert or resist attack. This program was intended to deliver technologies that could be used to build such a<br />
monitoring <strong>and</strong> management system. The goal was to create <strong>and</strong> validate architectures, algorithms, techniques, <strong>and</strong> automated<br />
tools that aid identification of coordinated attacks, assessment of system health, mission impact assessment, course of action<br />
selection, <strong>and</strong> help carry out effective security <strong>and</strong> survivability posture changes, either proactively or in response to the<br />
appearance of attacks.<br />
DTIC<br />
Computer Networks; Decision Support Systems; Images<br />
20060001906 Defense Advanced Research Projects Agency, Arlington, VA USA<br />
Scenario Customization for Information Extraction<br />
Yangarber, Roman; Jan. 1, 2001; 148 pp.; In English; Original contains color illustrations<br />
Report No.(s): AD-A440512; No Copyright; Avail.: Defense <strong>Technical</strong> Information Center (DTIC)<br />
Information Extraction (IE) is an emerging NLP technology, whose function is to process unstructured, natural language<br />
text, to locate specific pieces of information, or facts, in the text, <strong>and</strong> to use these facts to fill a database. IE systems today<br />
are commonly based on pattern matching. The core IE engine uses a cascade of sets of patterns of increasing linguistic<br />
complexity. Each pattern consists of a regular expression <strong>and</strong> an associated mapping from syntactic to logical form. The<br />
pattern sets are customized for each new topic, as defined by the set of facts to be extracted. Construction of a pattern base<br />
for a new topic is recognized as a time-consuming <strong>and</strong> expensive process--a principal roadblock to wider use of IE technology<br />
in the large.<br />
DTIC<br />
Extraction; Information Retrieval; Natural Language (Computers)<br />
20060001908 Maryl<strong>and</strong> Univ., College Park, MD USA<br />
Information Dynamics Applied to Link-State Routing<br />
Eom, Hyeonsang; Agrawala, Ashok K.; Noh, Sam H.; Shankar, A. U.; Nov. 1, 2001; 21 pp.; In English; Original contains<br />
color illustrations<br />
Contract(s)/Grant(s): F30602-00-2-0578<br />
Report No.(s): AD-A440518; CS-TR-4297; UMIACS-TR-2001-75; No Copyright; Avail.: Defense <strong>Technical</strong> Information<br />
Center (DTIC)<br />
Information Dynamics Agrawala, 2000 is an information-centric framework that provides a sufficient underst<strong>and</strong>ing of the<br />
characteristics of information used in systems for better system design <strong>and</strong> implementation. In this paper, we describe how<br />
to improve link-state routing based on this framework. Link-state routing protocols such as OSPF (Open Shortest Path<br />
First)Moy, 1991 are currently used in many networks. In link-state routing, routes are determined based on link-delay<br />
estimates, which are periodically flooded throughout the network. This flooding of link-delay estimates is done without<br />
considering the relevance of these estimates to routing quality, i.e. without taking into account the usefulness of the link -delay<br />
information. We have developed a new approach that improves link-state routing by estimating future link delays <strong>and</strong> flooding<br />
these estimates only to the extent that they are relevant. This means that we consider the dynamics of the link-delay<br />
information <strong>and</strong> its usefulness. Simulation studies suggest that our approach can lead to significant reductions in routing traffic<br />
with noticeable improvements of routing quality in high-load conditions, demonstrating the effectiveness of the framework.<br />
We plan to further investigate the conditions where our information-dynamics approach is better than the st<strong>and</strong>ard approach.<br />
DTIC<br />
Data Processing; Networks; Protocol (Computers)<br />
20060001910 Maryl<strong>and</strong> Univ., College Park, MD USA<br />
TaxonTree: Visualizing Biodiversity Information<br />
Parr, Cynthia S.; Lee, Bongshin; Campbell, Dana; Bederson, Benjamin B.; Jan. 1, 2003; 9 pp.; In English; Original contains<br />
color illustrations<br />
Contract(s)/Grant(s): F30602-03-2-0018<br />
Report No.(s): AD-A440523; No Copyright; Avail.: Defense <strong>Technical</strong> Information Center (DTIC)<br />
Biodiversity databases have recently become widely available to the public <strong>and</strong> to other researchers. To retrieve<br />
227
Change language