A Domain-Independent Algorithm for Plan Adaptation

The paradigms of transformational planning, case-based planning, and plan debugging all involve a process known as plan adaptation - modifying or repairing an old plan so it solves a new problem. In this paper we provide a domain-independent algorithm for plan adaptation, demonstrate that it is sound, complete, and systematic, and compare it to other adaptation algorithms in the literature. Our approach is based on a view of planning as searching a graph of partial plans. Generative planning starts at the graph's root and moves from node to node using plan-refinement operators. In planning by adaptation, a library plan - an arbitrary node in the plan graph - is the starting point for the search, and the plan-adaptation algorithm can apply both the same refinement operators available to a generative planner and can also retract constraints and steps from the plan. Our algorithm's completeness ensures that the adaptation algorithm will eventually search the entire graph and its systematicity ensures that it will do so without redundantly searching any parts of the graph.Comment: See http://www.jair.org/ for any accompanying file

Feedback Control and Characterization of a Microcantilever Using Optical Radiation Pressure

We describe a method for feedback-regulation of a microcantilever's response using optical radiation pressure. One laser measures the position of the cantilever and another laser applies a force that is a phase-shifted function of that position. The force is due solely to the momentum of the photons in the laser. The feedback changes the microcantilever's effective quality factor Qeff and effective temperature Teff. Reduction of both Qeff and Teff by more than a factor of 15 is demonstrated. Additionally, we suggest a method for determination of a microcantilever's spring constant using the known force exerted on it by radiation pressure.Comment: 10 pages, 3 figures. Updated acknowledgements and used smaller file format for Figure

Self-assembled Zeeman slower based on spherical permanent magnets

We present a novel type of longitudinal Zeeman slower. The magnetic field profile is generated by a 3D array of permanent spherical magnets, which are self-assembled into a stable structure. The simplicity and stability of the design make it quick to assemble and inexpensive. In addition, as with other permanent magnet slowers, no electrical current or water cooling is required. We describe the theory, assembly, and testing of this new design

Progress in the Analysis of Cosmic-Ray Observations

The report herein contained is of a preliminary character, and is intended to exhibit only the first steps of the problem in hand. At the Des Moines meeting of the American Physical Society on Dec. 31 last, the writer presented a paper in which were set forth details of a method of treating the observations of Millikan and Cameron upon the absorption of the cosmic-rays, in order to render them susceptible to adjustment by the method of least squares

A Simplified Deduction of Maxwell\u27s Distribution Law

It is the object of this paper, not to contribute to the volume of evidence for the validity of Maxwell\u27s molecular velocity law, or to improve upon the cogency of the various lines of argument which have previously led to it; but rather to bring the deduction within easy reach of any student of integral calculus who has knowledge of the merest rudiments of the theory of errors

A New Method of Identifying Polarized Light Reflected from Small Opaque Crystals.

The method is a modification of one used originally by Voigt for the identification of elliptically polarized light. The light under examination passes first through an arrangement of quartz wedges acting as a Babinet compensator, then through a rotator consisting of another pair of quartz wedges cut perpendicular to the axis, one from right-handed, the other from left-handed quartz; and finally through a large Nicol prism. The result is that the field is filled with rows of black spots in regular arrangement; and from the location of these spots with reference to the cross-hairs, as photographed, the exact character of the elliptic vibration can be readily calculated

On the Existence of a Minimum Volume in Solution

This research has for its general object to inquire into the physical condition of substances in near-saturated aqueous solution. The subject was attacked by means of experiments at different temperatures on the apparent specific volume in solution; by which is meant, the volume of that amount of solution which contains one gram of the solute, minus the natural volume of the water contained therein. This quantity is always somewhat less than the volume of the solid solute

Effect of Temperature Inequalities on the Balance

The topic herein presented had its origin in some work preliminary to another investigation, requiring the use of a sensitive balance operated with the greatest possible degree of precision. The balance used is by Sartorius, with 18 cm. beam and sensibility of about 2.3 scale divisions per mgr., pans empty, and so constructed that the sensibility increases slightly with moderate increase of load. The writer was studying this balance with a view to getting acquainted with its peculiarities, determining its constants and learning what degree of precision to expect of it (as should always be done with a new balance about to be used in particular work), and had taken a series of consecutive zero readings by the oscillating pointer method with pans empty, when a marked progressive change in the readings attracted immediate attention and demanded explanation

Calibration of a Gold Leaf Electrometer for Ionization Work

The ordinary type of ionization electroscope having a straight, horizontal scale of 100 divisions in the focal plane of its microscope, over which the image of the gold leaf is seen to move obliquely, is subject to well-marked variations which, for certain kinds of work, necessitate its calibration

Progress in the Analysis of Cosmic-Ray Observations (II)

One year ago the writer reported to this Academy the results of some preliminary calculations of the intensities of the three components assumed by Millikan to compose the cosmic radiation, based upon his last published data.1 At that time the Academy was so kind as to set apart a grant for a continuance of this research. Soon afterward, Dr. Millikan informed me that he was engaged upon a more elaborate series of depth-ionization measurements which promised greater precision, and extended the hope that the results would be available by fall. It was, however, not until February that the new data were received, and it was then found that the results would entail considerably more calculation than had been anticipated from the earlier set