17,862 research outputs found
Non-Traditional Entrants to the Profession of Teaching: Motivations and Experiences of Second-Career Educators
Individuals entering the teaching profession from other fields have much to offer in terms of practical experience in fields such as business, private industry, law enforcement, and the military. The authors examine the phenomenon of second-career teachers with specific emphasis on the motivating factors, common experiences, and reflections concerning the decision to leave already established professions in order to pursue a career in teaching. This particular issue of life vocation has particular interest for the Christian, who wishes to discern and follow the call of God in their personal and professional commitments. The article surveys research into second-career teachers and explores the process of professional preparation of these newfound entrants in the world of education as well as their assimilation to the culture of schools. Themes emerge from the literature for further consideration, which the authors argue, must more intentionally-inform career preparation programs, trends of new teacher recruitment, and teacher shortages in American school districts
Ephemeral Nebular Components in the Mildly Aqueously Altered CM Carbonaceous Chondrite LEW 85311
No abstract available
Reconfiguring Graph Homomorphisms on the Sphere
Given a loop-free graph , the reconfiguration problem for homomorphisms to
(also called -colourings) asks: given two -colourings of of a
graph , is it possible to transform into by a sequence of
single-vertex colour changes such that every intermediate mapping is an
-colouring? This problem is known to be polynomial-time solvable for a wide
variety of graphs (e.g. all -free graphs) but only a handful of hard
cases are known. We prove that this problem is PSPACE-complete whenever is
a -free quadrangulation of the -sphere (equivalently, the plane)
which is not a -cycle. From this result, we deduce an analogous statement
for non-bipartite -free quadrangulations of the projective plane. This
include several interesting classes of graphs, such as odd wheels, for which
the complexity was known, and -chromatic generalized Mycielski graphs, for
which it was not.
If we instead consider graphs and with loops on every vertex (i.e.
reflexive graphs), then the reconfiguration problem is defined in a similar way
except that a vertex can only change its colour to a neighbour of its current
colour. In this setting, we use similar ideas to show that the reconfiguration
problem for -colourings is PSPACE-complete whenever is a reflexive
-free triangulation of the -sphere which is not a reflexive triangle.
This proof applies more generally to reflexive graphs which, roughly speaking,
resemble a triangulation locally around a particular vertex. This provides the
first graphs for which -Recolouring is known to be PSPACE-complete for
reflexive instances.Comment: 22 pages, 9 figure
Evidence for Widespread Post-Hydration Heating of the CM Carbonaceous Chondrites
No abstract available
Nonrenewable Resource Prices: Deterministic or Stochastic Trends?
In this paper we examine temporal properties of eleven natural resource real price series from 1870-1990 by employing a Lagrangian Multiplier unit root test that allows for two endogenously determined structural breaks with and without a quadratic trend. Contrary to previous research, we find evidence against the unit root hypothesis for all price series. Our findings support characterizing natural resource prices as stationary around deterministic trends with structural breaks. This result is important in both a positive and normative sense. For example, without an appropriate understanding of the dynamics of a time series, empirical verification of theories, forecasting, and proper inference are potentially fruitless. More generally, we show that both pre-testing for unit roots with breaks and allowing for breaks in the forecast model can improve forecast accuracy.
Gauge drivers for the generalized harmonic Einstein equations
The generalized harmonic representation of Einstein's equations is manifestly hyperbolic for a large class of gauge conditions. Unfortunately most of the useful gauges developed over the past several decades by the numerical relativity community are incompatible with the hyperbolicity of the equations in this form. This paper presents a new method of imposing gauge conditions that preserves hyperbolicity for a much wider class of conditions, including as special cases many of the standard ones used in numerical relativity: e.g., K freezing, Gamma freezing, Bona-Massó slicing, conformal Gamma drivers, etc. Analytical and numerical results are presented which test the stability and the effectiveness of this new gauge-driver evolution system
A floor sensor system for gait recognition
This paper describes the development of a prototype floor sensor as a gait recognition system. This could eventually find deployment as a standalone system (eg. a burglar alarm system) or as part of a multimodal biometric system. The new sensor consists of 1536 individual sensors arranged in a 3 m by 0.5 m rectangular strip with an individual sensor area of 3 cm2. The sensor floor operates at a sample rate of 22 Hz. The sensor itself uses a simple design inspired by computer keyboards and is made from low cost, off the shelf materials. Application of the sensor floor to a small database of 15 individuals was performed. Three features were extracted : stride length, stride cadence, and time on toe to time on heel ratio. Two of these measures have been used in video based gait recognition while the third is new to this analysis. These features proved sufficient to achieve an 80 % recognition rate
Pillars Of Prosperity: Leveraging Regional Assets To Grow Minnesota's Economy
Minnesota has always been rich with assets -- a skilled labor force, good jobs in diverse industries, globally competitive companies, and abundant lakes and parks that provide a high quality of life for the people who call it home.However, to maintain its strong economy and quality of life, Minnesota must adapt to fast-changing trends in the global economy, trends that affect each of the state's regions and communities differently.This report explores how the state of Minnesota -- the governor's administration together with the Minnesota Legislature -- can partner with regional networks to foster economic growth and extend prosperity to greater numbers of Minnesotans
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