The Solar Cycle Field Reversal

A non-mathematical model of the solar cycle field reversal is presented. The basic process producing the reversal in this model is surface reconnection of higher latitude p-flux with lower latitude f-flux. This picture differs substantially from the reversal aspect of the solar cycle field geometry presented by Babcock (1961), but the discussion is carried out entirely within the context of the flux ropes he originally considered

Shaping Attitudes Toward Science in an Introductory Astronomy Class

At many universities, astronomy is a popular way for non-science majors to fulfill a general education requirement. Because general-education astronomy may be the only college-level science course taken by these students, it is the last chance to shape the science attitudes of these future journalists, teachers, politicians, and voters. I report on an attempt to measure and induce changes in science attitudes in my general-education astronomy course. I describe construction of the attitude survey, classroom activities designed to influence attitudes, and give numerical results indicating a significant improvement. In contrast, the literature on attitudes in introductory physics courses generally reports stagnation or decline. I briefly comment on some plausible explanations for this difference.Comment: v2 includes a copy of the surve

The Boot Lake MF imaging radar

The Middle-Atmosphere Imaging Radar is located at the Boot Lake field site, 10 miles east of Brighton, Colorado. It operates at 2.66 MHz with a 50-kW peak pulse power in 30 microsecond pulses. Ten independent coaxial-collinear antennas are used; five are parallel and run east-west, the other five are parallel and run north-south. Each antenna consists of eight half-wave dipoles. All ten antennas or a crossed pair may be used for transmission; all ten are sampled by pairs in rapid sequence for reception. The system is now operating on a campaign basis as a Fourier interferometer by measuring the complex voltages on the ten antennas and Fourier transforming them independently. Multiple scatterers within a single range gate, now sorted by velocity, can be located individually by their phase angles. The transmitted signal cycles through four modes (N-S linear, right-hand circular, E-W linear, and left-hand circular)

Comparative performances of stochastic competitive evolutionary neural tree (SCENT) with neural classifiers

A stochastic competitive evolutionary neural tree (SCENT) is described and evaluated against the best neural classifiers with equivalent functionality, using a collection of data sets chosen to provide a variety of clustering scenarios. SCENT is firstly shown to produce flat classifications at least as well as the other two neural classifiers used. Moreover its variability in performance over the data sets is shown to be small. In addition SCENT also produces a tree that can show any hierarchical structure contained in the data. For two real world data sets the tree captures hierarchical features of the data.Peer reviewe