1,141 research outputs found
First Documented Record of \u3ci\u3eOarisma Powesheik\u3c/i\u3e (Lepidoptera: Hesperiidae) in Canada
During a brief survey of the prairie areas near Vita, Manitoba, July 1985, Oarisma powesheik Parker was found to be abundant, although often local. Specimens collected constitute the first documented record for the species in Canada
Formula Pricing and Profit Sharing in Inter‐Firm Contracts
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109908/1/mde2704.pd
Perfectly-matched-layer truncation is exponentially accurate at high frequency
We consider a wide variety of scattering problems including scattering by Dirichlet, Neumann, and penetrable obstacles. We consider a radial perfectly-matched layer (PML) and show that for any PML width and a steep-enough scaling angle, the PML solution is exponentially close, both in frequency and the tangent of the scaling angle, to the true scattering solution. Moreover, for a fixed scaling angle and large enough PML width, the PML solution is exponentially close to the true scattering solution in both frequency and the PML width. In fact, the exponential bound holds with rate of decay c (omicrontanθ − C)k where omicron is the PML width and θ is the scaling angle. More generally, the results of the paper hold in the framework of black-box scattering under the assumption of an exponential bound on the norm of the cutoff resolvent, thus including problems with strong trapping. These are the first results on the exponential accuracy of PML at high-frequency with non-trivial scatterers
Chapter 7 : Use of Assessments to Inform Educational Policies in French-Speaking Belgium
In French-speaking Belgium, the national assessments developed only lately, and there are not yet national assessments developed by professionals that can be used to evaluate trends. Therefore, the only tools available to rigorously evaluate trends are international assessments. French-speaking Belgium has participated in international assessments since the early 1970s and their results are highly valued by policy-makers. Their level of awareness of the strengths and weaknesses of the education system can be considered as good. However, until recently, the impact of international assessments on education policies has been limited. Only scattered initiatives have been taken. From 2014, an extremely ambitious plan called Pacte pour un enseignement d’excellence has been launched. The Pact tackles most of the systemic weaknesses of the education system in FS Belgium and addresses at the same time structural change (lowering grade repetition, moving to a comprehensive lower secondary education), curricular changes and governance in a long-term perspective. A significant reform of the system of national assessments is currently under discussion
Decompositions of High-Frequency Helmholtz Solutions via Functional Calculus, and Application to the Finite Element Method
Over the last 10 years, results from [J. M. Melenk and S. Sauter, Math. Comp., 79 (2010), pp. 1871–1914], [J. M. Melenk and S. Sauter, SIAM J. Numer. Anal., 49 (2011), pp. 1210–1243], [S. Esterhazy and J. M. Melenk, Numerical Analysis of Multiscale Problems, Springer, New York, 2012, pp. 285–324] and [J. M. Melenk, A. Parsania, and S. Sauter, J. Sci. Comput., 57 (2013), pp. 536–581] decomposing high-frequency Helmholtz solutions into “low-” and “high-” frequency components have had a large impact in the numerical analysis of the Helmholtz equation. These results have been proved for the constant-coefficient Helmholtz equation in either the exterior of a Dirichlet obstacle or an interior domain with an impedance boundary condition. Using the Helffer–Sjöstrand functional calculus [B. Helffer and J. Sjöstrand, Schrödinger Operators, Springer, Berlin, 1989, pp. 118–197] this paper proves analogous decompositions for scattering problems fitting into the black-box scattering framework of Sjöstrand and Zworski [J. Amer. Math. Soc., 4 (1991), pp. 729–769] thus covering Helmholtz problems with variable coefficients, impenetrable obstacles, and penetrable obstacles all at once. These results allow us to prove new frequency-explicit convergence results for (i) the hp-finite-element method (hp-FEM) applied to the variable-coefficient Helmholtz equation in the exterior of an analytic Dirichlet obstacle, where the coefficients are analytic in a neighborhood of the obstacle, and (ii) the h-FEM applied to the Helmholtz penetrable-obstacle transmission problem. In particular, the result in (i) shows that the hp-FEM applied to this problem does not suffer from the pollution effect
A socio-phonetic study of a Quebec French community: Trois-Rivieres
This study of urban dialectology consists of an
invest.igation of some aspects of the French phonological
system in the city of Trois-Rivieres, Province of Quebec.
The corpus of data includes a series of sixty recorded interviews
which provides conparable speech samples from a
significant cross-section of Trifluvians, who are stratified
according to age, sex, occupation and education. The
data obtained from these interviews represent the sociolinguistic
variation existing in Trois-Rivieres and the
inter-individual diversity within this speech community.
Descriptions on the methods of sampling, collection
of data, the quantitative analysis of phonological
variables, and interview construction eliciting different
speech styles are made in chapter 1, together with a general
description of the situation of the French language
in Quebec and Canada.
To study the variation existing in the Trifluvian
speech community, seven phonological variables are subjected
to special examination. These.consist of four vocalic variables,
i.e. (a),(e),(eu),(o), and three consonantal variables, namely (g), (ch), (r). The analysis of the co-variation
of these phonological variables and sociological and stylistic
factors is made throughout chapter 2. In this latter
chapter, questions concerning the extent of the linguistic
variation present, the causes of linguistic diversity and
the process of linguistic change are also treated.
Chapter 3 is devoted to the examination of general
attitudes of speakers towards language and to the correlation
of their subjective attitudes with their objective
linguistic behaviour observed in chapter 2.
The final chapter, or the synthesis, studies the
processes in which the variables are involved end their
consequences for the evolution of the Trifluvian sociolinguistic system
Ground state of the Kagome-like S=1/2 antiferromagnet, Volborthite Cu3V2O7(OH)2.2H2O
Volborthite compound is one of the very few realizations of S=1/2 quantum
spins on a highly frustrated kagome-like lattice. Low-T SQUID measurements
reveal a broad magnetic transition below 2K which is further confirmed by a
peak in the 51V nuclear spin relaxation rate (1/T1) at 1.4K0.2K. Through
51V NMR, the ground state (GS) appears to be a mixture of different spin
configurations, among which 20% correspond to a well defined short range order,
possibly of the type. While the freezing involve all
the Cu spins, only 40% of the copper moment is actually frozen which
suggests that quantum fluctuations strongly renormalize the GS.Comment: 4 pages, 4 figures, to appear in PR
- …