Concurrent Image Processing Executive (CIPE)

The design and implementation of a Concurrent Image Processing Executive (CIPE), which is intended to become the support system software for a prototype high performance science analysis workstation are discussed. The target machine for this software is a JPL/Caltech Mark IIIfp Hypercube hosted by either a MASSCOMP 5600 or a Sun-3, Sun-4 workstation; however, the design will accommodate other concurrent machines of similar architecture, i.e., local memory, multiple-instruction-multiple-data (MIMD) machines. The CIPE system provides both a multimode user interface and an applications programmer interface, and has been designed around four loosely coupled modules; (1) user interface, (2) host-resident executive, (3) hypercube-resident executive, and (4) application functions. The loose coupling between modules allows modification of a particular module without significantly affecting the other modules in the system. In order to enhance hypercube memory utilization and to allow expansion of image processing capabilities, a specialized program management method, incremental loading, was devised. To minimize data transfer between host and hypercube a data management method which distributes, redistributes, and tracks data set information was implemented

Knowledge-based vision and simple visual machines

The vast majority of work in machine vision emphasizes the representation of perceived objects and events: it is these internal representations that incorporate the 'knowledge' in knowledge-based vision or form the 'models' in model-based vision. In this paper, we discuss simple machine vision systems developed by artificial evolution rather than traditional engineering design techniques, and note that the task of identifying internal representations within such systems is made difficult by the lack of an operational definition of representation at the causal mechanistic level. Consequently, we question the nature and indeed the existence of representations posited to be used within natural vision systems (i.e. animals). We conclude that representations argued for on a priori grounds by external observers of a particular vision system may well be illusory, and are at best place-holders for yet-to-be-identified causal mechanistic interactions. That is, applying the knowledge-based vision approach in the understanding of evolved systems (machines or animals) may well lead to theories and models that are internally consistent, computationally plausible, and entirely wrong

Multiaxis thrust vectoring using axisymmetric nozzles and postexit vanes on an F/A-18 configuration vehicle

A ground-based investigation was conducted on an operational system of multiaxis thrust vectoring using postexit vanes around an axisymmetric nozzle. This thrust vectoring system will be tested on the NASA F/A-18 High Alpha Research Vehicle (HARV) aircraft. The system provides thrust vectoring capability in both pitch and yaw. Ground based data were gathered from two separate tests at NASA Langley Research Center. The first was a static test in the 16-foot Transonic Tunnel Cold-Jet Facility with a 14.25 percent scale model of the axisymmetric nozzle and the postexit vanes. The second test was conducted in the 30 by 60 foot wind tunnel with a 16 percent F/A-18 complete configuration model. Data from the two sets are being used to develop models of jet plume deflection and thrust loss as a function of vane deflection. In addition, an aerodynamic interaction model based on plume deflection angles will be developed. Results from the scale model nozzle test showed that increased vane deflection caused exhaust plume turning. Aerodynamic interaction effects consisted primarily of favorable interaction of moments and unfavorable interaction of forces caused by the vectored jet plume

Data-Driven Constitutional Avoidance

This article uses a case study to explain how empirical analysis can promote judicial modesty. In Matal v. Tam, the U.S. Supreme Court invoked the First Amendment to strike down the Lanham Act\u27s bar on federal registration of disparaging trademarks. The Tam decision has great constitutional significance. It expands First Amendment coverage into a new field of economic regulation, and it deepens the constitutional prohibition on viewpoint-based speech regulations. This article contends that empirical analysis could have given the Court a narrower basis for the Tam result, one that would have avoided the fraught First Amendment issues the Court decided. The Tam challenge came from an Asian-American rock band that calls itself The Slants -as a means to re-appropriate an anti-Asian slur. The authors performed an original empirical study of how Americans understand the term slants. The data show that both Asian-Americans and non-Asian-Americans understand the term variably based on its context. Both groups recognize the term\u27s derogatory meaning, but they also understand the use of the term by an Asian-American band as an effort to re-appropriate the derogatory term. This contextual variation in how Americans understand the term slants exposes the incoherence of the Lanham Act\u27s flat treatment of certain terms as uniformly disparaging. That incoherence supports the legal conclusion that the disparagement bar is unconstitutionally vague. A finding of vagueness in Tam would have achieved relative constitutional avoidance, invalidating the disparagement bar on a narrower, less constitutionally significant ground than the actual decision\u27s First Amendment analysis. Constitutional avoidance serves judicial modesty values that courts and our broader legal culture tend to portray favorably. This article\u27s study and analysis provide a model for other situations in which empirical data can give courts a path to constitutional avoidance

Nuclear magnetic resonance structural studies of allergen protein

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1994.Includes bibliographical references.by Gregory L. Warren.Ph.D

Taming Uncivil Discourse

In an era of increasingly intense populist politics, a variety of issues of intergroup prejudice, discrimination, and conflict have moved center stage in American politics. Among these is “political correctness” and, in particular, what constitutes a legitimate discourse of political conflict and opposition. Yet the meaning of legitimate discourse is being turned on its head as some disparaged groups seek to reclaim, or re-appropriate, the slurs directed against them. Using a Supreme Court decision about whether “The Slants” – a band named after a traditional slur against Asians – can trademark its name, we test several hypotheses about re-appropriation processes, based on a nationally representative sample with an oversample of Asian-Americans and several survey experiments. In general, we find that contextual factors influence how people understand and evaluate potentially disparaging words, and we suggest that the political discourse of intergroup relations in the U.S. has become more complicated by processes of re-appropriation

The first-time homebuyer : the builder's perspective

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1991.Includes bibliographical references (leaves 46-47).by Gregory L. Petrini.M.S

The ectodomain of Toll-like receptor 9 is cleaved to generate a functional receptor.

Mammalian Toll-like receptors (TLRs) 3, 7, 8 and 9 initiate immune responses to infection by recognizing microbial nucleic acids; however, these responses come at the cost of potential autoimmunity owing to inappropriate recognition of self nucleic acids. The localization of TLR9 and TLR7 to intracellular compartments seems to have a role in facilitating responses to viral nucleic acids while maintaining tolerance to self nucleic acids, yet the cell biology regulating the transport and localization of these receptors remains poorly understood. Here we define the route by which TLR9 and TLR7 exit the endoplasmic reticulum and travel to endolysosomes in mouse macrophages and dendritic cells. The ectodomains of TLR9 and TLR7 are cleaved in the endolysosome, such that no full-length protein is detectable in the compartment where ligand is recognized. Notably, although both the full-length and cleaved forms of TLR9 are capable of binding ligand, only the processed form recruits MyD88 on activation, indicating that this truncated receptor, rather than the full-length form, is functional. Furthermore, conditions that prevent receptor proteolysis, including forced TLR9 surface localization, render the receptor non-functional. We propose that ectodomain cleavage represents a strategy to restrict receptor activation to endolysosomal compartments and prevent TLRs from responding to self nucleic acids