125,050 research outputs found
Nonparametric Regression using the Concept of Minimum Energy
It has recently been shown that an unbinned distance-based statistic, the
energy, can be used to construct an extremely powerful nonparametric
multivariate two sample goodness-of-fit test. An extension to this method that
makes it possible to perform nonparametric regression using multiple
multivariate data sets is presented in this paper. The technique, which is
based on the concept of minimizing the energy of the system, permits
determination of parameters of interest without the need for parametric
expressions of the parent distributions of the data sets. The application and
performance of this new method is discussed in the context of some simple
example analyses.Comment: 10 pages, 4 figure
Direct observation of voids in the vacancy excess region of ion bombarded silicon
The results reported in this letter indicate that the spatial separation of the vacancy and interstitial excesses which result from ion bombardment gives rise to stable voids upon annealing at 850 °C even for implants where the projected ion range is only of the order of a few thousand Ångstrom. Such voids have been observed directly by transmission electron microscopy. Furthermore, in cases where both voids and interstitial-based defects are present at different depths, it is found that Au has a strong preference for decorating void surfaces and hence Au can, indeed, be used as a selective detector of open volume defects in Si.One of the authors ~J.W.-L.!
acknowledges the Australian Research Council for financial
support
ASSESSING THE ECONOMIC IMPACTS OF INTEGRATED PEST MANAGEMENT: LESSONS FROM THE PAST, DIRECTIONS FOR THE FUTURE
This paper reviews the literature assessing the economic impacts of integrated pest management (IPM). Definitions of IPM are categorized as input- or outcome-oriented, and an outcome- oriented definition is recommended for public program assessment. The literature on economic impact assessment of IPM is divided according to focus on expected profit, profitability risk, environment, and health. Measuring diverse impacts on the environment and health poses a challenge, as does placing a value on those impacts. Evaluation of environment and health variables has been accomplished either by comparing individual attributes (multiple criteria approach) or else by constructing a weighted index (index approach), which may be measured in monetary or non- monetary terms. While partial budgeting represents an accepted measure of short-term expected profitability effects of IPM practices, the three other focal areas are much more costly and complicated to measure. For routine IPM project assessments, simple indicators of health and environmental impacts are needed that can be used to extrapolate upon valuation measures from prior, published studies.Crop Production/Industries,
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Black and Asian police officers and support staff: prejudice, identity, agency and social cohesion
This primary research paper presents a review of research that finds that the British Government’s new social cohesion agenda does hold promise for racial and ethnic prejudice reduction – but that social cohesion policies and practice must include at their core policies to reduce institutional racism in British police services. Analysis of the literature reveals that considerably more research is required to examine the precise nature and dynamics of institutional racism within the police services. There is a need to understand how racism against Black and minority ethnic (BME) police employees, and police racism against BME communities, influences social cohesion. That this is important, given the British government’s current social cohesion policy agenda, is patently clear. Considerably more research is about to be undertaken in this area by the authors of this paper and the results will be published in the academic press, disseminated at conferences and presented in training programmes
Correlation functions of the One-Dimensional Random Field Ising Model at Zero Temperature
We consider the one-dimensional random field Ising model, where the spin-spin
coupling, , is ferromagnetic and the external field is chosen to be
with probability and with probability . At zero temperature, we
calculate an exact expression for the correlation length of the quenched
average of the correlation function in the case that is not an integer. The
result is a discontinuous function of . When , we also
place a bound on the correlation length of the quenched average of the
correlation function .Comment: 12 pages (Plain TeX with one PostScript figure appended at end), MIT
CTP #220
Low noise tunnel diode receivers for satellite application
Low noise tunnel diode receivers for satellite application
New results in rho^0 meson physics
We compare the predictions of a range of existing models based on the Vector
Meson Dominance hypothesis with data on e^+ e^- -> pi^+ pi^$ and e^+ e^- ->
mu^+ mu^- cross-sections and the phase and near-threshold behavior of the
timelike pion form factor, with the aim of determining which (if any) of these
models is capable of providing an accurate representation of the full range of
experimental data. We find that, of the models considered, only that proposed
by Bando et al. is able to consistently account for all information, provided
one allows its parameter "a" to vary from the usual value of 2 to 2.4. Our fit
with this model gives a point-like coupling (gamma pi^+ \pi^-) of magnitude ~
-e/6, while the common formulation of VMD excludes such a term. The resulting
values for the rho mass and pi^+ pi^- and e^+e^- partial widths as well as the
branching ratio for the decay omega -> pi^+ pi^- obtained within the context of
this model are consistent with previous results.Comment: 34 pages with 7 figures. Published version also available at
http://link.springer.de/link/service/journals/10052/tocs/t8002002.ht
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