61,653 research outputs found
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
Infant Day Care and the Working Mother: A Proposal for Reducing Maternal Anxiety
My interest in the day care of children of working mothers was stimulated by my recent involvement in a study of the need for day care facilities in Kitchener-Waterloo. During this study it became apparent that most of the facilities and the interest in day care programs was related specifically to the care and education of children ages three to five. In reviewing the findings of a questionnaire used in the study however, it was readily determined that another problem existed. A total of 75 of 170 working mothers from industry stated that they placed a total of 84 infants with relatives and babysitters while they were at work. One-half of these infants were cared for outside of their homes. Approximately one-half of the mothers indicated that they had been forced to make two or more arrangements during the year and the majority stated that arrangements were hard to make.
This paper deals with three main areas. Initially, it attempts to address the general issues surrounding the provision of infant day care services. Secondly, it presents a point of view regarding the type of facility needed in the Kitchener-Waterloo area. Thirdly, it proposes the undertaking of an initial study devoted to examining the effects of a specific type of infant day care program in reducing anxiety in the low-income working mother from industry
AI mass spectrometers for space shuttle health monitoring
The facility Hazardous Gas Detection System (HGDS) at Kennedy Space Center (KSC) is a mass spectrometer based gas analyzer. Two instruments make up the HGDS, which is installed in a prime/backup arrangement, with the option of using both analyzers on the same sample line, or on two different lines simultaneously. It is used for monitoring the Shuttle during fuel loading, countdown, and drainback, if necessary. The use of complex instruments, operated over many shifts, has caused problems in tracking the status of the ground support equipment (GSE) and the vehicle. A requirement for overall system reliability has been a major force in the development of Shuttle GSE, and is the ultimate driver in the choice to pursue artificial intelligence (AI) techniques for Shuttle and Advanced Launch System (ALS) mass spectrometer systems. Shuttle applications of AI are detailed
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)
Lightweight magnesium-lithium alloys show promise
Evaluation tests show that magnesium-lithium alloys are lighter and more ductile than other magnesium alloys. They are being used for packaging, housings, containers, where light weight is more important than strength
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
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