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.

Baseline advanced RAIM user algorithm and possible improvements

Abstract: We present a baseline multiple fault and multiconstellation advanced receiver autonomous integrity monitoring user algorithm for vertical guidance. After reviewing the navigation requirements for localizer performance with vertical guidance down to 200 feet, we describe in detail how to process the pseudorange measurements, the nominal error models, and the prior fault probabilities to obtain the protection levels and other figures of merit. In particular, we show how to determine which fault modes must be monitored and a method for performing fault exclusion. Finally, we present a list of possible algorithm improvements and simplifications.

Protocol independence through disjoint encryption

Abstract: One protocol (called the primary protocol) is independent of other protocols (jointly called the secondary protocol) if the question whether the primary protocol achieves a security goal never depends on whether the secondary protocol is in use. We use multiprotocol strand spaces to prove that two cryptographic protocols are independent if they use encryption in non-overlapping ways. This theorem applies even if the protocols share public key certificates and secret key "tickets". We use the method of Guttman et al. (2000) to study penetrator paths, namely sequences of penetrator actions connecting regular nodes (message transmissions or receptions) in the two protocols. Of special interest are inbound linking paths, which lead from a message transmission in the secondary protocol to a message reception in the primary protocol. We show that bundles can be modified to remove all inbound linking paths, if encryption does not overlap in the two protocols. The resulting bundle does not depend on any activity of the secondary protocol. We illustrate this method using the Neuman-Stubblebine protocol as an example.

Gaia Data Release 1. Open cluster astrometry: performance, limitations, and future prospects

Abstract: Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information. Aims. We investigate the scientific potential and limitations of the TGAS component by means of the astrometric data for open clusters. Methods. Mean cluster parallax and proper motion values are derived taking into account the error correlations within the astrometric solutions for individual stars, an estimate of the internal velocity dispersion in the cluster, and, where relevant, the effects of the depth of the cluster along the line of sight. Internal consistency of the TGAS data is assessed. Results. Values given for standard uncertainties are still inaccurate and may lead to unrealistic unit-weight standard deviations of least squares solutions for cluster parameters. Reconstructed mean cluster parallax and proper motion values are generally in very good agreement with earlier Hipparcos-based determination, although the Gaia mean parallax for the Pleiades is a significant exception. We have no current explanation for that discrepancy. Most clusters are observed to extend to nearly 15 pc from the cluster centre, and it will be up to future Gaia releases to establish whether those potential cluster-member stars are still dynamically bound to the clusters. Conclusions. The Gaia DR1 provides the means to examine open clusters far beyond their more easily visible cores, and can provide membership assessments based on proper motions and parallaxes. A combined HR diagram shows the same features as observed before using the Hipparcos data, with clearly increased luminosities for older A and F dwarfs.

An Examination of the Conceptual Issues Involved in Developing Credit-Scoring Models

Abstract: Multiple discriminant analysis (MDA) is frequently used to develop statistical credit-scoring models for loan evaluation purposes. Current legislative efforts to insure that credit is being granted in a nondiscriminatory manner have focused considerable attention on the reliability of such models. This article examines the theoretical requirements of the MDA model in the context of a realistic lending situation and illustrates the extent of bias when these theoretical assumptions are not fully met. The article concludes that failure to rigorously meet all the theoretical assumptions of the statistical model may not be as critical as insuring that credit managers fully understand the limitations of these types of decision tools. Furthermore, the evidence indicates that statistical models other than multiple discriminant analysis are possibly more relevant to the credit-granting decision.

Readings in Intelligent User Interfaces

Abstract: Introduction I: Multimedia Input Analysis II: Multimedia Presentation Design III: Automated Graphic Design IV: Automated Layout V: User and Discourse Modeling VI: Model Based Interfaces VII: Agent Interfaces VIII: Evaluation