7,194 research outputs found
Flexible arms provide constant force for pressure switch calibration
In-place calibration of a pressure switch is provided by a system of radially oriented flexing arms which, when rotated at a known velocity, convert the centrifugal force of the arms to a linear force along the shaft. The linear force, when applied to a pressure switch diaphragm, can then be calculated
Phase diagram of the three-dimensional Anderson model of localization with random hopping
We examine the localization properties of the three-dimensional (3D) Anderson
Hamiltonian with off-diagonal disorder using the transfer-matrix method (TMM)
and finite-size scaling (FSS). The nearest-neighbor hopping elements are chosen
randomly according to . We find that the
off-diagonal disorder is not strong enough to localize all states in the
spectrum in contradistinction to the usual case of diagonal disorder. Thus for
any off-diagonal disorder, there exist extended states and, consequently, the
TMM converges very slowly. From the TMM results we compute critical exponents
of the metal-insulator transitions (MIT), the mobility edge , and study
the energy-disorder phase diagram.Comment: 4 pages, 5 EPS figures, uses annalen.cls style [included]; presented
at Localization 1999, to appear in Annalen der Physik [supplement
Shifts in U.S. Relative Wages: The Role of Trade, Technology, and Factor Endowments
This paper investigates three hypotheses to account for the observed shifts in U.S. relative wages of less educated workers compared to more educated workers during the period from 1967 to 1992: (1) increased import competition, (2) changes in the relative supplies of labor of different educational levels, and (3) changes in technology. Our analysis relies on a basic relationship of the standard general equilibrium trade model that relates changes in product prices to factor price changes and factor shares, together with information about changes in the composition of output and trade, within-industry factor use, and factor supplies. For the period from 1967 to 1973, we conclude that the relative increase in the supply of well-educated labor was the dominant economic force that narrowed the wage gap among workers of different educational levels. In the 1980s and early 1990s, however, the wage gap between more educated and less educated workers widened sharply, despite the continued relative increase in the supply of workers with more education. We conclude that increased import competition cannot account for the observed increase in inequality among the major education groups, although it could have been a contributory cause of the decrease in the relative wages of the least educated workers. Instead, we find support for technical progress that is saving of less educated labor and that is more rapid in some manufacturing sectors intensively using highly educated labor as the dominant force in widening the wage gaps among college-educated workers, workers with a completed high school education, and workers with 1–11 years of schooling. Finally, we use the Deardorff-Staiger model, which allows changes in the factor content of trade to reveal the effects of trade on relative factor prices. Our empirical tests reinforce the conclusion that increased import competition between 1977 and 1987 was not the dominant force in widening the wage
Automatic mapping of the geomagnetic field
Automatic mapping of geomagnetic field & electric current flow in ionospher
OGO-2 Magnetic Field Observations During the Magnetic Storm of March 13-15, 1966
Magnetic disturbances examined for correlation of surface and satellite magnetic field measurement
Feature Selection on Hyperspectral Data for Dismount Skin Analysis
Many security applications require the ability to accurately identify dismounts based on their distinctive identification properties. A dismount can be identified by many personal characteristics to include clothing, height, and gait. In particular, a dismount\u27s skin can be used as an identifying feature because of the vast variability of skin pigmentation amongst individuals. Hyperspectral data, which is comprised of hundreds of spectral channels sampled from a nearly contiguous electromagnetic spectrum, is used to detect skin spectral variability amongst dismounts. However, hyperspectral data is often highly correlated and computationally expensive to process. Feature selection methods can be employed to reduce the data to a manageable size. This thesis presents the results of applying the fast correlation based filter (FCFB) [51] to a data set that contains hyperspectral data from the forearms of 62 subjects. The reduced data is used to train an artificial neural network (ANN) to discriminate a dismount of interest (DOI) amongst a group of 4 non-DOI\u27s. The trained model is then tested to find the same DOI amongst a group of 62 new non-DOI\u27s. The FCBF selected four features (1014, 1024, 1033, and 1348nm) to discriminate amongst the dismounts. Using these four features, the ANN on average misclassified dismounts amongst four separate DOI validation tests. More specifically, the amount of possible DOI suspects was reduced from 62 to 4 dismounts. The FCBF outperformed three other feature selection methods with 4 times less misclassified instances
A global magnetic anomaly map
A subset of POGO satellite magnetometer data has been formed that is suitable for analysis of crustal magnetic anomalies. Using a thirteenth order field model, fit to these data, magnetic residuals have been calculated over the world to latitude limits of plus 50 deg. These residuals averaged over one degree latitude-longitude blocks represent a detailed global magnetic anomaly map derived solely from satellite data. Preliminary analysis of the map indicates that the anomalies are real and of geological origin
Medically Modified Eyes: A Baptismal Cataract Surgery in Clement of Alexandria
In Paedagogus 1.6.28, Clement describes baptism through the metaphor of a cataract surgery that enables the percipient to see God. In antiquity, cataract surgery was neither a common nor a safe procedure, which raises the question: why does Clement use such an unlikely metaphor for baptism? In this article, I demonstrate that this medical metaphor of cataract surgery enabled Clement to blur the line between the physical and the spiritual. The visual component of the metaphor allowed Clement to draw from Epicurean sensory perception and epistemology, which understood objects to emit tiny films that entered the eye of the body, with repeated contact leading to concept formation, in order to describe how the eye of the soul could see God once it has been transformed through baptism. For Clement, it is only through baptism that the cataract can be removed, thereby providing the baptized Christian with deified eyes to see God. In addition to having her cataract removed, according to Clement, the nature of the baptized Christian\u27s vision changes from intromission to extramission, from receiving films to emitting a visual ray back to the divine. I further argue that the medical component of the metaphor allows Clement to describe the baptized Christian as fundamentally different from the rest of humanity and as part of an elite group that has undergone this uncommon and dangerous cataract surgery. Through these two aspects of his metaphor, Clement describes and defines Christians in terms of their medically modified eyes that enable them to see and to know God
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