Groupthink and the Classroom: Changing Familiar Patterns to Encourage Critical Thought

Groupthink is an unhealthy decision-making pattern characterized by a high degree of cohesiveness and a striving for consensus among the members of a decision-making group. This article considers the classroom as a potential contributor to the groupthink phenomenon, comparing the antecedent conditions for group think with typical classroom conditions and expectations. With a plausible, though unproven, link between the classroom and group think decision making, four suggestions are offered teachers for encouraging independent thought and action in students. The four suggestions include adding critical-thinking skills, decision-making skills, small group communication skills, and conflict management skills to the curriculum. These additions are possible and valuable at every educational level

Probability Density Functions of Observed Rainfall in Montana

The question of whether a rain rate probability density function (PDF) can vary uniformly between precipitation events is examined. Image analysis on large samples of radar echoes is possible because of advances in technology. The data provided by such an analysis easily allow development of radar reflectivity factors (and by extension rain rate) distribution. Finding a PDF becomes a matter of finding a function that describes the curve approximating the resulting distributions. Ideally, one PDF would exist for all cases; or many PDF's that have the same functional form with only systematic variations in parameters (such as size or shape) exist. Satisfying either of theses cases will, validate the theoretical basis of the Area Time Integral (ATI). Using the method of moments and Elderton's curve selection criteria, the Pearson Type 1 equation was identified as a potential fit for 89 percent of the observed distributions. Further analysis indicates that the Type 1 curve does approximate the shape of the distributions but quantitatively does not produce a great fit. Using the method of moments and Elderton's curve selection criteria, the Pearson Type 1 equation was identified as a potential fit for 89% of the observed distributions. Further analysis indicates that the Type 1 curve does approximate the shape of the distributions but quantitatively does not produce a great fit

Beam control of extremely agile relaying laser source for bifocal relay mirror spacecraft

The concept of controlling optical laser beams on spacecraft for acquisition, tracking and pointing purposes is quickly becoming a reality. As a result, fine pointing of laser beams is turn out to be an increasingly important research topic. A unique testbed was constructed in order to study and develop new methods for laser beam control. This testbed, the Moving Target-Source Test Fixture (MTSTF), hosts a laser source, the Extremely Agile Relaying Laser Source (EARLS), which has the capability of automatically acquiring and directing a laser beam onto a satellite simulator while in motion. The purpose of this thesis is to make the EARLS platform operational by developing a tracking control system. The ultimate goal is to point the laser beam at the satellite simulatorâ s receiving telescope and maintain the laser within the telescopeâ s limits in the presence of structural disturbance induced by the EARLS motion.http://archive.org/details/beamcontrolofext109452630Approved for public release; distribution is unlimited

Mid-Infrared Optical Frequency Combs based on Difference Frequency Generation for Molecular Spectroscopy

Mid-infrared femtosecond optical frequency combs were produced by difference frequency generation of the spectral components of a near-infrared comb in a 3-mm-long MgO:PPLN crystal. We observe strong pump depletion and 9.3 dB parametric gain in the 1.5 \mu m signal, which yields powers above 500 mW (3 \mu W/mode) in the idler with spectra covering 2.8 \mu m to 3.5 \mu m. Potential for broadband, high-resolution molecular spectroscopy is demonstrated by absorption spectra and interferograms obtained by heterodyning two combs.Comment: 11 pages, 8 figure

Shaping metallic glasses by electromagnetic pulsing

With damage tolerance rivalling advanced engineering alloys and thermoplastic forming capabilities analogous to conventional plastics, metallic glasses are emerging as a modern engineering material. Here, we take advantage of their unique electrical and rheological properties along with the classic Lorentz force concept to demonstrate that electromagnetic coupling of electric current and a magnetic field can thermoplastically shape a metallic glass without conventional heating sources or applied mechanical forces. Specifically, we identify a process window where application of an electric current pulse in the presence of a normally directed magnetic field can ohmically heat a metallic glass to a softened state, while simultaneously inducing a large enough magnetic body force to plastically shape it. The heating and shaping is performed on millisecond timescales, effectively bypassing crystallization producing fully amorphous-shaped parts. This electromagnetic forming approach lays the groundwork for a versatile, time- and energy-efficient manufacturing platform for ultrastrong metals

Ohio Principals’ Perceptions of Communication Skills, Factors, and Courses Among Criteria for Secondary- Teacher Effectiveness

In a recent article in Communication Education, Curtis, Winsor, and Stephens (1989) presented the results of a study that assessed managers’ perceptions of the skills and abilities of greatest significance in the business setting. The authors concluded “It is our belief and the belief of perspective (sic) employers throughout the United States that courses such as public speaking, listening, and interpersonal communication should be included as an oral communication core in (business programs)” (p. 13). The present study seeks to expand their findings and beliefs to a secondary-education setting. Specifically, this paper presents the results of a survey study conducted using a sample of secondary principals from the state of Ohio. The primary research question was “What skills, factors, and coursework are considered of greatest importance by secondary principals as administrators involved in the hiring and evaluation of secondary teachers?” A second question was “How do principals rate communication skills and courses when considering teacher effectiveness?” The intent of the authors was to examine the perceptions of secondary principals to determine tentative answers to these questions answers to these questions. Principles were chosen because they play a central role in the teacher-effectiveness discussion. As educational administrators, most are directly involved in applying effectiveness standards to their schools. In addition, this study attempts to provide some empirical support for the assertions and suggestions of Dewitt, et all., (1991) as they argue for an increased role for oral-communication theory and practice in education, and for Allen and Shaw (1990) who assert that communication behaviors are related to teaching effectiveness in the perceptions of supervisors of teachers