Mitre Corporation

About: Mitre Corporation is a company organization based out in Bedford, Massachusetts, United States. It is known for research contribution in the topics: Air traffic control & National Airspace System. The organization has 4884 authors who have published 6053 publications receiving 124808 citations. The organization is also known as: Mitre & MITRE.

Assessment of clinical parameters associated with increased frequency of mutant T cells in patients with systemic lupus erythematosus.

Abstract: Objective. To determine the clinical features that contribute to an increased frequency of mutant T cells (FMC) in patients with systemic lupus erythematosus (SLE). Methods. During in vivo T cell division, there are errors in replication which give rise to mutations throughout the genome. An estimate of such mutations may be obtained by focusing on mutations in the hprt gene, which can be screened by assessing relative growth of T cell clones in the presence and absence of 6-thioguanine. In this study, peripheral blood T cell clones from 47 patients with SLE were assessed, and the frequency of mutant T cells (FMC) determined. An attempt was made to correlate the FMC with disease measures. Results. Patients with SLE had a spectrum of FMC values, ranging from normal to almost 1,000 times normal. Total duration of active disease (rs = 0.94), past highest disease activity index (rs = 0.80), and number of lupus flares (rs = 0.76) correlated most strongly (P < 0.0001) with FMC by Spearman's rank order analysis. In contrast, current disease activity index and current anti-DNA level did not correlate with FMC. Similar correlations between FMC and cumulative past lupus disease activity were found by linear regression analysis (rp = 0.89 for the correlation between the natural logarithm of FMC and cumulative duration of active disease). By both statistical tests, therapy was found to be only a minor contributor to FMC. Conclusion. In our patient population, a high FMC value appears to reflect cumulative clinical lupus disease activity, involving both intensity and duration of past active disease.

The Status of the Nominal in Persian Complex Predicates

Abstract: The nature of preverbal nominals and their relation to the verb have been the focus of much debate in languages with a productive complex predication process. For Persian, certain analyses have argued that the bare nominals in complex predicate constructions are distinct from bare objects, while others have treated the two types of bare nominals uniformly. This paper argues that the two categories of preverbal nouns cannot receive the same analysis since they display distinct syntactic and semantic behavior: the preverbal nominals, unlike the bare object nouns, cannot be questioned, are modified differently, have different interpretations, give rise to distinct case-assignment contexts, and can co-occur with a non-specific object. The distinct properties of the two nominal categories are captured by positing distinct structural positions for these nouns. Non-specific bare nouns are internal arguments of the thematic verb, while the nominal element of the complex predicate construction is part of the verbal domain with which it combines through a process of conflation, as defined in Hale and Keyser (2002), to form a single predicate.

Representing Attribute-Based Concepts in a Classifier System

Abstract: Legitimate concerns have been raised about the expressive adequacy of the classifier language. This paper shows that many of those concerns stem from the inadequacies of the binary encodings typically used with classifier systems, not the classifier language per se. In particular, we describe some straightforward binary encodings for attribute-based instance spaces. These encodings give classifier systems the ability to represent ordinal and nominal attributes as expressively as most symbolic machine learning systems, without sacrificing the building blocks required by the genetic algorithm.

When Are Group Scheduling Tools Useful

Abstract: A geographically dispersed department at the MITRE Corporation participated in a field test of groupware tools. This paper documents the results of their use of a group scheduling tool, Meeting Maker Version 1.5. Research in the late 1980s showed that early group scheduling tools were not useful, in part because they only benefited some users and hence critical mass could not be attained. This study was undertaken to determine whether and how far the tools have evolved. Participants said that Meeting Maker made it easy to schedule meetings and maintain their calendars, and 90% wished to continue using it after the study was complete. Problems were noted when not everyone used or had access to the tool, and three generic solutions are discussed: capabilities that allow users to communicate with non-users, capabilities that allow users to stay connected, and lightweight methods of participation.

A PDF multisensor multitarget tracker

Abstract: A previously presented probability density function (pdf) multitarget tracker is extended to a more complex and difficult problem. The input data is bearing measurements from multiple sensors over time, which includes clutter (false alarms) and true measurements (from detected targets) with errors. Targets may be missed. The output is the real-time determination of the number of targets present and their geographic x,y location. The implementation is the recursive numerical computation of the discrete pdf of each target and is derived from the conceptual joint pdf of all targets.