18,733 research outputs found
Method of making impurity-type semiconductor electrical contacts Patent
Fabrication of sintered impurity semiconductor brushes for electrical energy transfe
Improved molybdenum disulfide-silver motor brushes have extended life
Motor brushes of proper quantities of molybdenum disulfide and copper or silver are manufactured by sintering techniques. Graphite molds are used. These brushes operate satisfactorily for long periods in normal atmosphere or in a high-vacuum environment
The Online Laboratory: Conducting Experiments in a Real Labor Market
Online labor markets have great potential as platforms for conducting
experiments, as they provide immediate access to a large and diverse subject
pool and allow researchers to conduct randomized controlled trials. We argue
that online experiments can be just as valid---both internally and
externally---as laboratory and field experiments, while requiring far less
money and time to design and to conduct. In this paper, we first describe the
benefits of conducting experiments in online labor markets; we then use one
such market to replicate three classic experiments and confirm their results.
We confirm that subjects (1) reverse decisions in response to how a
decision-problem is framed, (2) have pro-social preferences (value payoffs to
others positively), and (3) respond to priming by altering their choices. We
also conduct a labor supply field experiment in which we confirm that workers
have upward sloping labor supply curves. In addition to reporting these
results, we discuss the unique threats to validity in an online setting and
propose methods for coping with these threats. We also discuss the external
validity of results from online domains and explain why online results can have
external validity equal to or even better than that of traditional methods,
depending on the research question. We conclude with our views on the potential
role that online experiments can play within the social sciences, and then
recommend software development priorities and best practices
As-built specification for CLASSY conversion
There are no author-identified significant results in this report
Greater data science at baccalaureate institutions
Donoho's JCGS (in press) paper is a spirited call to action for
statisticians, who he points out are losing ground in the field of data science
by refusing to accept that data science is its own domain. (Or, at least, a
domain that is becoming distinctly defined.) He calls on writings by John
Tukey, Bill Cleveland, and Leo Breiman, among others, to remind us that
statisticians have been dealing with data science for years, and encourages
acceptance of the direction of the field while also ensuring that statistics is
tightly integrated.
As faculty at baccalaureate institutions (where the growth of undergraduate
statistics programs has been dramatic), we are keen to ensure statistics has a
place in data science and data science education. In his paper, Donoho is
primarily focused on graduate education. At our undergraduate institutions, we
are considering many of the same questions.Comment: in press response to Donoho paper in Journal of Computational
Graphics and Statistic
Crop identification using ERTS imagery
Digital analysis of August 15 ERTS-I imagery for southeastern South Dakota was performed to determine the feasibility of conducting crop surveys from satellites. Selected areas of bands 4, 5, 6, and 7 positive transparencies were converted to digital form utilizing Signal Analysis and Dissemination Equipment (SADE). The optical transmission values were printed out in a spatial format. Visual analysis of the printouts indicated that cultivated areas were readily distinguished from non-cultivated areas in all four bands. Bare soil was easily recognized in all four bands. Corn and soybeans, the two major crops in the area, were treated as separate classes rather than as a single class called row crops. Bands 6 and 7 provided good results in distinguishing between corn and soybeans
Contact stresses calculated for miniature slip rings
Using mathematical formulations to plot the graphs of the contact preload versus the Hertzian load, calculations of unit loading of the preloaded brushes on slip rings can be made. This optimizes the design of contact brushes and miniature slip rings
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