170,496 research outputs found
Constructing cell data for diagram algebras
We show how the treatment of cellularity in families of algebras arising from
diagram calculi, such as Jones' Temperley--Lieb wreaths, variants on Brauer's
centralizer algebras, and the contour algebras of Cox et al (of which many
algebras are special cases), may be unified using the theory of tabular
algebras. This improves an earlier result of the first author (whose hypotheses
covered only the Brauer algebra from among these families).Comment: Approximately 38 pages, AMSTeX. Revised in light of referee comments.
To appear in the Journal of Pure and Applied Algebr
Possibility of observing MSSM charged Higgs in association with a W boson at LHC
Possibility of observing associated production of charged Higgs and W boson
in the framework of MSSM at LHC is studied. Both leptonic and hadronic decays
of W boson are studied while the charged Higgs boson is considered to decay to
a lepton and a neutrino. Therefore two search categories are defined
based on the leptonic and hadronic final states, i.e.
and where or and is a light jet from
decay. The discovery chance of the two categories is evaluated at an
integrated luminosity of 300 \invfb at LHC. It is shown that both leptonic and
hadronic final states have the chance of discovery at high \tanb. Finally
and contours are provided for both search categories.Comment: 20 pages, 19 figure
The evolution of ideas and practice concerning the provision of children's playspace (with a special reference to New Zealand and Palmerston North) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Social Science at Massey University
This thesis seeks to explore the historical processes underlying the allocation and use of public space for children's play in nineteenth and twentieth century industrial society and examine how the processes have influenced the New Zealand situation.
The form of publicly provided playspace in New Zealand borrows extensively from overseas ideas and practices. The origins of playspace were a response to the conditions existing as a result of industrialisation in the late nineteenth century. The convergence of two streams of thought; the first the use of play as a tool for social integration of migrant children in the United States; and secondly the development of an urban parks system to alleviate the industrial blight of the cityscape in the United Kingdom; led to the establishment of recreation standards for the provision of children's playspace. The transportable nature of these ideas and practices resulted in children's playgrounds developing in New Zealand between 1920 and 1970 in a largely similar way. During this same period ideas concerning child constructed playgrounds and safety were evolving overseas. Such ideas when adopted in New Zealand have influenced the appearance and internal design of New Zealand playgrounds. However, in terms of function and form these changes have only been superficial.
Within New Zealand the social mechanisms for determining the allocation and design of playgrounds has constrained the use of playgrounds often to the disadvantage of different societal groups. The thesis concludes with a review of this issue
Variability of Internally Generated Turbulence in an Estuary, from 100 Days of Continuous Observations
We present detailed observations of internally generated turbulence in a sheared, stratified natural flow, as well as an analysis of the external factors leading to its generation and temporal variability. Multi-month time series of vertical profiles of velocity, acoustic backscatter (0.5 Hz), and turbulence parameters were collected with two moored acoustic Doppler current profilers (ADCPs) in the Hudson River estuary, and estuary-long transects of water density were collected 30 times. ADCP backscatter is used for visualization of coherent turbulent structures and evaluation of surface wave biases to the turbulence measurements. Benefits of the continuous long-term turbulence record include our capturing: (1) the seasonality of turbulence due to changing riverflow, (2) hysteresis in stratification and turbulence over the fortnightly cycle of tidal range, and (3) intermittent events such as breaking internal waves. Internal mixing layers (IMLs) are defined as turbulent regions above the logarithmic velocity layer, and the bottom boundary layer (BBL) is defined as the continuously turbulent range of heights above the bed. A cross-correlation analysis reveals how IML and BBL turbulence vary with stratification and external forcing from tidal range, river flow, and winds. Turbulence in both layers is maximal at spring tide and minimal when most stratified, with one exception IML turbulence at a site with changing channel depth and width is maximal at times of maximum stratification and freshwater input
Implications of SUSY Model Building
We discuss the motivations and implications of models of low-energy
supersymmetry. We present the case for the minimal supersymmetric standard
model, which we define to include the minimal particle content and soft
supersymmetry-breaking interactions which are universal at the GUT or Planck
scale. This model is in agreement with all present experimental results, and
yet depends on only a few unknown parameters and therefore maintains
considerable predictive power. From the theoretical side, it arises naturally
in the context of supergravity models. We discuss radiative electroweak
symmetry breaking and the superpartner spectrum in this scenario, with some
added emphasis on regions of parameter space leading to unusual or interesting
experimental signals at future colliders. We then examine how these results may
be affected by various modifications and extensions of the minimal model,
including GUT effects, extended gauge, Higgs, and matter sectors, non-universal
supersymmetry breaking, non-conservation of R-parity, and dynamical
supersymmetry breaking at low energies.Comment: Contribution to the DPF long range study, working group on
'Electroweak Symmetry Breaking and Beyond the SM Physics'; LaTeX file without
figures, 60 pages. The complete PS file, including figures, can be obtained
by anonymous ftp from
ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-879.ps.
Unified life detection system: A concept
Systematic investigation of techniques and hardware which could be utilized in life detection system has resulted in identification of group of candidate concepts and selection of "unified system". Theme of concept permits greatest flexibility in procedural details for experiments which can be performed in individual ampules
A Deep Infrared Search for AXP 1E 1841-045
Multi-colour (JHKs) imaging and photometry of the field of the Anomalous
X-ray Pulsar AXP 1E 1841-045 is analysed in the light of new, accurate
coordinates from Chandra (Wachter et al, 2004). From excellentquality images,
we find multiple sources in and around the position error circle. Of these,
none can be confidently identified as the infrared counterpart. The limiting
magnitudes reached were J=22.1, H=20.7 and Ks=19.9$ (95% confidence).Comment: 8 pages LaTeX, 2 eps figures; ApJ accepte
The blocks of the Brauer algebra in characteristic zero
We determine the blocks of the Brauer algebra in characteristic zero. We also give information on the submodule structure of standard modules for this algebra
Approximate Bayesian Computation in State Space Models
A new approach to inference in state space models is proposed, based on
approximate Bayesian computation (ABC). ABC avoids evaluation of the likelihood
function by matching observed summary statistics with statistics computed from
data simulated from the true process; exact inference being feasible only if
the statistics are sufficient. With finite sample sufficiency unattainable in
the state space setting, we seek asymptotic sufficiency via the maximum
likelihood estimator (MLE) of the parameters of an auxiliary model. We prove
that this auxiliary model-based approach achieves Bayesian consistency, and
that - in a precise limiting sense - the proximity to (asymptotic) sufficiency
yielded by the MLE is replicated by the score. In multiple parameter settings a
separate treatment of scalar parameters, based on integrated likelihood
techniques, is advocated as a way of avoiding the curse of dimensionality. Some
attention is given to a structure in which the state variable is driven by a
continuous time process, with exact inference typically infeasible in this case
as a result of intractable transitions. The ABC method is demonstrated using
the unscented Kalman filter as a fast and simple way of producing an
approximation in this setting, with a stochastic volatility model for financial
returns used for illustration
Rare earth elements in Andaman Island surface water : geochemical tracers for the monsoon
The Asian summer monsoon affects the lives of billions of people. With the aim of identifying geochemical tracers for the monsoon related freshwater input from the major rivers draining into the Bay of Bengal and Andaman Sea we have taken surface seawater samples from various locations up and down the Andaman Islands during 2011. Importantly, in some locations samples have been taken in March, July and November, covering most of a seasonal cycle and different monsoon phases. Samples were collected from the side of small wooden boats or while swimming and were filtered within a few hours at 0.45 or 0.22 microns using the vacuum produced by a water jet or a hand operated peristaltic pump. Filtered and unfiltered samples were acidified to < pH 2 and analysed for Y and the REEs with an automated online preconcentration ICP-MS technique [1].
The local input of REEs from streams and sediment rich areas such as mangrove environments is clearly identified by middle REE enrichments in the shale normalised patterns of some samples. These middle REE bulges accompany large increases in dissolved REE concentrations at some locations, especially for the July samples obtained during the peak monsoon season with frequent storms. Y/Ho fractionation aslo occurs during the local input of dissolved REEs with affected samples having lower Y/Ho ratios. Conversly, some samples, in particular those taken after heavy rainfall in March, show strong REE scavenging accompanied by the prefferential removal of dissolved light REEs and higher Y/Ho ratios.
The time series at a location away from local input sources shows remarkably similar REE patterns and concentraions in March and July. Then in October-November, following the peak in monsoon river discharge, the dissolved REE concentration increases by almost a factor of 2. The notable exception to this seasonal pattern is the Ce anomally which is around 0.3 in March and November but 0.6 in July, implying less oxidative removal of Ce(IV) during the peak summer monsoon rains. With the exception of elevated dissolved Ce concentrations, the North Pacific Deep Water normalised REE patterns are similar to those reported for offshore samples from the Bay of Bengal and Andaman Sea [2]. These seawater normalised patterns are distinctive having a middle REE enriched arc with similar light and heavy REE values suggesting the input from large rivers in the region is traceable using seawater REE chemistry.
[1] Hathorne et al. (2012), Online preconcentration ICP-MS analysis of rare earth elements in seawater, Geochem. Geophys. Geosyst., 13, Q01020, doi:10.1029/2011GC003907.
[2] Amakawa et al. (2000), Geochim. Cosmochim. Acta 64, 1715-1727
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