2,547 research outputs found

    User's guide for NETS/PROSSS

    Get PDF
    Expensive analysis programs are often combined with optimization procedures to solve engineering problems. To obtain an optimal solution requires numerous iterations between the analysis program and the optimizer. This often becomes prohibitive due to the cost and amount of computer time needed to converge to an optimal solution. NETS/PROSSS was developed to address this problem. The purpose of this paper is to serve as a user's guide for NETS/PROSSS. The key features include the neural network, determining the training pairs for the neural network, and the approximated analysis/optimization process. A small problem is given to serve as an example of how to apply the system

    Stochastic oscillations of adaptive networks: application to epidemic modelling

    Full text link
    Adaptive-network models are typically studied using deterministic differential equations which approximately describe their dynamics. In simulations, however, the discrete nature of the network gives rise to intrinsic noise which can radically alter the system's behaviour. In this article we develop a method to predict the effects of stochasticity in adaptive networks by making use of a pair-based proxy model. The technique is developed in the context of an epidemiological model of a disease spreading over an adaptive network of infectious contact. Our analysis reveals that in this model the structure of the network exhibits stochastic oscillations in response to fluctuations in the disease dynamic.Comment: 11 pages, 4 figure

    Uncoupling of T Cell Receptor Zeta Chain Function during the Induction of Anergy by the Superantigen, Staphylococcal Enterotoxin A

    Get PDF
    Staphylococcus aureus enterotoxins have immunomodulatory properties. In this study, we show that Staphylococcal enterotoxin A (SEA) induces a strong proliferative response in a murine T cell clone independent of MHC class II bearing cells. SEA stimulation also induces a state of hypo-responsiveness (anergy). We characterized the components of the T cell receptor (TCR) during induction of anergy by SEA. Most interestingly, TCR zeta chain phosphorylation was absent under SEA anergizing conditions, which suggests an uncoupling of zeta chain function. We characterize here a model system for studying anergy in the absence of confounding costimulatory signals

    IMPACT OF HUMAN CHARACTERISTICS IN BASIC UNDERWATER DEMOLITION/SEAL (BUD/S) TRAINING PERFORMANCE

    Get PDF
    Reporting and clerical functions at Naval Special Warfare (NSW) Echelon IV commands are ripe for digitization, automation, and optimization. This study utilizes a restricted digitalized NSW dataset to showcase how “big data” in the context of SEAL training can be used to predict performance success of various Basic Underwater Demolition/SEAL (BUD/S) training evolutions. Our study focuses on multiple human characteristics and compares their correlation to evolution pass rates in training using Ordinary Least Squares (OLS) for our prediction model. From our initial regression analysis of over 232,000 data points, our findings indicate higher pass rates for BUD/S candidates who are older, married, and officers, as well as increased pass rates in individuals who were taller, lighter, and right-handed. Lower pass rates are found among minorities. The Black population had high fail rates in the evolutions that involve water activities. This study is an example of how long-term efficiencies could be gained from greater automation of data using simple software that could provide long-term benefit if captured in a more persistent and accurate manner. We advocate for the implementation of a more automated data/software collection system that can capture each student's training career in one cohesive data profile. Moving forward, NSW studies should continue to leverage the use of “big data” to optimize its performance across all domains of the force.Approved for public release. Distribution is unlimited.Lieutenant, United States NavyLieutenant, United States Nav

    A representation of the natural numbers by means of cycle-numbers, with consequences in number theory

    Get PDF
    In this paper we give rules for creating a number triangle T in a manner analogous to that for producing Pascal’s arithmetic triangle; but all of its elements belong to {0, 1}, and cycling of its rows is involved in the creation. The method of construction of any one row of T from its preceding rows will be defined, and that, together with starting and boundary conditions, will suffice to define the whole triangle, by sequential continuation. We shall use this triangle in order to define the so-called cycle-numbers, which can be mapped to the natural numbers. T will be called the ‘cyclenumber triangle’. First we shall give some theorems about relationships between the cyclenumbers and the natural numbers, and discuss the cycling of patterns within the triangle’s rows and diagonals. We then begin a study of figures (i.e. (0,1)patterns, found on lines, triangles and squares, etc.) within T. In particular, we shall seek relationships which tell us something about the prime numbers. For our later studies, we turn the triangle onto its side and work with a doubly-infinite matrix C. We shall find that a great deal of cycling of figures occurs within T and C, and we exploit this fact whenever we can. The phenomenon of cycling patterns leads us to muse upon a ‘music of the integers’, indeed a ‘symphony of the integers’, being played out on the cycle-number triangle or on C. Like Pythagoras and his ‘music of the spheres’, we may well be the only persons capable of hearing it! Keywords: cycle-number triangle, cycle-number, prime cycle-number

    A principled approach to the measurement of situation awareness in commercial aviation

    Get PDF
    The issue of how to support situation awareness among crews of modern commercial aircraft is becoming especially important with the introduction of automation in the form of sophisticated flight management computers and expert systems designed to assist the crew. In this paper, cognitive theories are discussed that have relevance for the definition and measurement of situation awareness. These theories suggest that comprehension of the flow of events is an active process that is limited by the modularity of attention and memory constraints, but can be enhanced by expert knowledge and strategies. Three implications of this perspective for assessing and improving situation awareness are considered: (1) Scenario variations are proposed that tax awareness by placing demands on attention; (2) Experimental tasks and probes are described for assessing the cognitive processes that underlie situation awareness; and (3) The use of computer-based human performance models to augment the measures of situation awareness derived from performance data is explored. Finally, two potential example applications of the proposed assessment techniques are described, one concerning spatial awareness using wide field of view displays and the other emphasizing fault management in aircraft systems
    corecore