Induction of First-Order Decision Lists: Results on Learning the Past Tense of English Verbs

This paper presents a method for inducing logic programs from examples that learns a new class of concepts called first-order decision lists, defined as ordered lists of clauses each ending in a cut. The method, called FOIDL, is based on FOIL (Quinlan, 1990) but employs intensional background knowledge and avoids the need for explicit negative examples. It is particularly useful for problems that involve rules with specific exceptions, such as learning the past-tense of English verbs, a task widely studied in the context of the symbolic/connectionist debate. FOIDL is able to learn concise, accurate programs for this problem from significantly fewer examples than previous methods (both connectionist and symbolic).Comment: See http://www.jair.org/ for any accompanying file

A COST-EFFECTIVENESS ANALYSIS OF ACTIONS TO REDUCE STREAM TEMPERATURE AT THE WATERSHED SCALE

A cost-effectiveness frontier is developed to compare economic and environmental tradeoffs associated with planting a riparian buffer to reduce stream temperature at the watershed scale. Results indicate that total welfare change and its distribution among sectors vary between scenarios. The policy selected may differ if riparian plantings are voluntary rather than mandatory.Environmental Economics and Policy, Land Economics/Use,

OPTIMAL SPATIAL SCALE FOR EVALUATING ECONOMIC AND ENVIRONMENTAL TRADEOFFS

This paper develops a conceptual framework that can provide a scientific foundation for formulating policies that consider environmental and economic tradeoffs. It addresses a critical problem recognized in the environmental sciences, namely, choosing the appropriate spatial scale for measurement and analysis of spatially variable economic and biophysical processes.scale, carbon sequestration, agriculture, economic policy, Environmental Economics and Policy, Industrial Organization,

Interferometric mapping of Magnetic fields: G30.79 FIR 10

We present polarization maps of G30.79 FIR 10 (in W43) from thermal dust emission at 1.3 mm and from CO J=$2 \to 1$ line emission. The observations were obtained using the Berkeley-Illinois-Maryland Association array in the period 2002-2004. The G30.79 FIR 10 region shows an ordered polarization pattern in dust emission, which suggests an hourglass shape for the magnetic field. Only marginal detections for line polarization were made from this region. Application of the Chandrashkar-Fermi method yielded $B_{pos} \approx 1.7$ mG and a statistically corrected mass to magnetic flux ratio $\lambda_{C} \approx 0.9$, or essentially critical.Comment: 11 pages, 2 Figures, Published in Ap

A study of the energy content of the seismic waves P and pP

The energy observed in the seismic waves P and pP in a large number of earthquakes is compared, by means of two partly independent methods, with the theoretical energy calculated from a standard equation. The results are analyzed, depth of focus, distance from epicenter to observing station, geographical location of epicenter, and azimuth from station being used as variables. When compared with the theoretical ratio, the ratio of the energy in pP to the energy in P averaged over a distance range 60°-90° is observed to decrease with depth, by 0.5 on a logarithmic scale of energy between 100 and 600 km. depth of focus. The results for the two waves are compared separately with theoretical values, and the observed effect appears to be about equally due to an increase of P energy and a decrease of pP energy with depth. The theoretical formula is reëxamined to determine if permissible changes in the assumptions or numerical values can account for the results. No such changes are found; certain assumptions with respect to increased absorption of energy near the surface of the earth provide a partial qualitative explanation, but quantitatively they cannot be reconciled with data from other sources. The variation with distance between observed and calculated energies is not large enough to be treated quantitatively; slight changes in the slope of the accepted velocity vs. depth curve are tentatively suggested on the basis of it. The energy ratio pP/P compared to the theoretical ratio is significantly too large in shallow earthquakes occurring in the Aleutian region and can be attributed to pP rather than P. For shallow shocks in the New Hebrides region and very deep shocks of the Southwest Pacific there is some indication that the energy ratio is smaller than for comparable shocks elsewhere. Data on observed wave periods are given. The effect of differences between instruments is considered

Alien Registration- Mooney, James M. (Houlton, Aroostook County)

https://digitalmaine.com/alien_docs/34810/thumbnail.jp