34,688 research outputs found
The construction, utilization, and evaluation of a series of exercises designed to improve the oral language of second grade children
Thesis (Ed.M.)--Boston Universit
Some Results On Normal Homogeneous Ideals
In this article we investigate when a homogeneous ideal in a graded ring is
normal, that is, when all positive powers of the ideal are integrally closed.
We are particularly interested in homogeneous ideals in an N-graded ring
generated by all homogeneous elements of degree at least m and monomial ideals
in a polynomial ring over a field. For ideals of the first trype we generalize
a recent result of S. Faridi. We prove that a monomial ideal in a polynomial
ring in n indeterminates over a field is normal if and only if the first n-1
positive powers of the ideal are integrally closed. We then specialize to the
case of ideals obtained by taking integral closures of m-primary ideals
generated by powers of the variables. We obtain classes of normal monomial
ideals and arithmetic critera for deciding when the monomial ideal is not
normal.Comment: 19 page
Who is Selling the Ivory Tower? Sources of Growth in University Licensing
Historically, commercial use of university research has been viewed in terms of spillovers. Recently, there has been a dramatic increase in technology transfer through licensing as universities attempt to appropriate the returns from faculty research. This change has prompted concerns regarding the source of this growth - specifically, whether it suggests a change in the nature of university research. We develop an intermediate input model to examine the extent to which the growth in licensing is due to the productivity observable inputs or driven by a change in the propensity of faculty and administrators to engage in commercializing university research. We model licensing as a three stage process, each involving multiple inputs. Nonparametric programming techniques are applied to survey data from 65 universities to calculate total factor productivity (TFP) growth in each state. To examine the sources of TFP growth, the productivity analysis is augmented by survey evidence from business who license-in university inventions. Results suggest that increased licensing is due primarily to an increased willingness of faculty and administrators to license and increased business reliance on external R&D rather than a shift in faculty research.
Are Faculty Critical? Their Role in University-Industry Licensing
Understanding the nature of the involvement of faculty in university licensing is im-portant for understanding how technology is transferred through licensing as well as more controversial issues, such as the need for university licensing. Using data from a survey of firms that actively license-in from universities we explore the importance of faculty in the licensing and development of inventions, as well as how and why they are used and how the use of faculty relates to characteristics of firms. In particular we find that the use of faculty through sponsored research in lieu of a license is closely related to the amount of basic research conducted by firms whereas the use of faculty within the terms of a license is related to the prevalence of personal contacts between industry R&D researchers and university faculty.
Interstate Cigarette Bootlegging: Extent, Revenue Losses, and Effects of Government Intervention
In this paper, we develop and estimate a model of commercial smuggling in which some, but not all, firms smuggle a portion of the cigarettes they sell. The model is used to examine the effects on interstate cigarette smuggling of the Contraband Cigarette Act and a change in the federal excise tax. We find that both policies have unintentional effects. While the Contraband Cigarette Act was imposed to reduce interstate smuggling, we find it had the opposite effect. In contrast, an increase in the federal tax is not intended to affect smuggling, but we find it increases the portion of cigarette sales that is commercially smuggled.
Online Bin Covering: Expectations vs. Guarantees
Bin covering is a dual version of classic bin packing. Thus, the goal is to
cover as many bins as possible, where covering a bin means packing items of
total size at least one in the bin.
For online bin covering, competitive analysis fails to distinguish between
most algorithms of interest; all "reasonable" algorithms have a competitive
ratio of 1/2. Thus, in order to get a better understanding of the combinatorial
difficulties in solving this problem, we turn to other performance measures,
namely relative worst order, random order, and max/max analysis, as well as
analyzing input with restricted or uniformly distributed item sizes. In this
way, our study also supplements the ongoing systematic studies of the relative
strengths of various performance measures.
Two classic algorithms for online bin packing that have natural dual versions
are Harmonic and Next-Fit. Even though the algorithms are quite different in
nature, the dual versions are not separated by competitive analysis. We make
the case that when guarantees are needed, even under restricted input
sequences, dual Harmonic is preferable. In addition, we establish quite robust
theoretical results showing that if items come from a uniform distribution or
even if just the ordering of items is uniformly random, then dual Next-Fit is
the right choice.Comment: IMADA-preprint-c
A Nitsche-based cut finite element method for a fluid--structure interaction problem
We present a new composite mesh finite element method for fluid--structure
interaction problems. The method is based on surrounding the structure by a
boundary-fitted fluid mesh which is embedded into a fixed background fluid
mesh. The embedding allows for an arbitrary overlap of the fluid meshes. The
coupling between the embedded and background fluid meshes is enforced using a
stabilized Nitsche formulation which allows us to establish stability and
optimal order \emph{a priori} error estimates,
see~\cite{MassingLarsonLoggEtAl2013}. We consider here a steady state
fluid--structure interaction problem where a hyperelastic structure interacts
with a viscous fluid modeled by the Stokes equations. We evaluate an iterative
solution procedure based on splitting and present three-dimensional numerical
examples.Comment: Revised version, 18 pages, 7 figures. Accepted for publication in
CAMCo
Geometric mutual information at classical critical points
A practical use of the entanglement entropy in a 1d quantum system is to
identify the conformal field theory describing its critical behavior. It is
exactly for an interval of length in an infinite system,
where is the central charge of the conformal field theory. Here we define
the geometric mutual information, an analogous quantity for classical critical
points. We compute this for 2d conformal field theories in an arbitrary
geometry, and show in particular that for a rectangle cut into two rectangles,
it is proportional to . This makes it possible to extract in classical
simulations, which we demonstrate for the critical Ising and 3-state Potts
models.Comment: 5 pages. v3: published versio
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