Digital computer processing of X-ray photos

Digital computers correct various distortions in medical and biological photographs. One of the principal methods of computer enhancement involves the use of a two-dimensional digital filter to modify the frequency spectrum of the picture. Another computer processing method is image subtraction

Man-machine interactive imaging and data processing using high-speed digital mass storage

The role of vision in teleoperation has been recognized as an important element in the man-machine control loop. In most applications of remote manipulation, direct vision cannot be used. To overcome this handicap, the human operator's control capabilities are augmented by a television system. This medium provides a practical and useful link between workspace and the control station from which the operator perform his tasks. Human performance deteriorates when the images are degraded as a result of instrumental and transmission limitations. Image enhancement is used to bring out selected qualities in a picture to increase the perception of the observer. A general purpose digital computer, an extensive special purpose software system is used to perform an almost unlimited repertoire of processing operations

Laser-assisted electron-argon scattering at small angles

Electron-argon scattering in the presence of a linearly polarized, low frequency laser field is studied theoretically. The scattering geometries of interest are small angles where momentum transfer is nearly perpendicular to the field, which is where the Kroll-Watson approximation has the potential to break down. The Floquet R matrix method solves the velocity gauge Schr\"odinger equation, using a larger reaction volume than previous treatments in order to carefully assess the importance of the long range polarization potential to the cross section. A comparison of the cross sections calculated with the target potential fully included inside 20 and 100 a.u. shows no appreciable differences, which demonstrates that the long range interaction can not account for the high cross sections measured in experiments.Comment: 2 figure

Automobile Prices, Gasoline Prices, and Consumer Demand for Fuel Economy

The relationship between gasoline prices and the demand for vehicle fuel efficiency is important for environmental policy but poorly understood in the academic literature. We provide empirical evidence that automobile manufacturers price as if consumers respond to gasoline prices. We derive a reduced-form regression equation from theoretical micro-foundations and estimate the equation with nearly 300,000 vehicle-week-region observations over the period 2003-2006. We find that vehicle prices generally decline in the gasoline price. The decline is larger for inefficient vehicles, and the prices of particularly efficient vehicles actually rise. Structural estimation that ignores these effects underestimates consumer preferences for fuel efficiency.Automobiles, Gasoline, Consumer Preference, Demand, Fuel Efficiency

Asymmetric information and the role of FED watching

Federal Open Market Committee ; Monetary policy - United States

Augmented information in a theory of ambiguity, credibility and inflation

Monetary policy - United States ; Money supply

The Entry Incentives of Complementary Producers: A Simple Model with Implications for Antitrust Policy

We model competition between two firms in a vertical upstream-downstream relationship. Each firm can pay a sunk cost to enter the other’s market. For equilibria in which both firms enter, the downstream price can be lower than the joint profit maximizing level, and coordination (e.g., through merger) is anticompetitive.

Coherent Perfect Rotation

Two classes of conservative, linear, optical rotary effects (optical activity and Faraday rotation) are distinguished by their behavior under time reversal. In analogy with coherent perfect absorption, where counterpropagating light fields are controllably converted into other degrees of freedom, we show that only time-odd (Faraday) rotation is capable of coherent perfect rotation in a linear and conservative medium, by which we mean the complete transfer of counterpropagating coherent light fields into their orthogonal polarization. This highlights the necessity of time reversal odd processes (not just absorption) and coherence in perfect mode conversion and may inform device design.Comment: 4 pages, 2 figure