15,442 research outputs found
Techniques for Using SCATS as an Incident Management Tool
This paper will discuss how SCATS (Sydney Co-ordinated Adaptive Traffic System), used widely throughout New Zealand, can be used to manage the sudden change in traffic demand resulting from incidents on the transport network. SCATS is an adaptive traffic signal control system that uses real time traffic information (loop detectors) to adjust phase splits, cycle times and offsets to optimise a signalised traffic network, resulting in reduced delays to motorists. This paper will focus on how SCATS can be modified to detect and respond to incidents.
Various tools are available within SCATS to handle unique traffic situations, such as those resulting from incidents. These include action plans, variation routines, using the unusual congestion monitor and the ITS port. The benefits of using these tools will be shown using a an S-Paramics traffic model linked to SCATS with FUSE. This allows various incidents to be modelled in a microsimulation model with the signals operating under SCATS control. The model used includes the Northern Motorway on Auckland’s North Shore with various diversion routes off of the motorway. Various incidents will be modelled on and off of the motorway, showing traffic diversions on the arterial network. This case study will show how travel time on diversion routes used during incidents, can be decreased by using the SCATS as an incident management tool.
This paper will discuss incident management strategies, the various SCATS tools available to handle incident scenarios, and present the benefits of these SCATS tools using a case study
Atlantic menhaden, Brevoortia tyrannus, Purse Seine Fishery, 1972-84, with a brief discussion of age and size composition of the Landings
This report summarizes (I) annual purse seine landings of Atlantic menhaden, Brevoortia tyrannus, for 1972-84, (2) estimated numbers of fish caught by fishing area. (3) estimates of nominal fishing effort and catch-per-unit-effort, (4) mean fish length and weight, and (5) major changes in the fishery. During the 1970s stock size and recruitment increased and the age composition broadened. reversing trends witnessed during the fishery's decline in the 1960s. Landings steadily improved and by 1980 the total coast wide landings exceeded 400,000 metric tons.
Nevertheless, the character of the fishery changed considerably. Eleven reduction plants processed fish at seven ports in 1972, but in 1984 only eight plants
operated at live ports. Beginning in the mid-1960s the center of fishing aclivity shifted from the Middle Atlantic area to the Chesapeake Bay area, which has continued to dominate the fishery in landings and effort through the 1970s and 1980s. During this period the average size and age of fish in the catches declined. (PDF file contains 30 pages.
Non-additive properties of finite 1D Ising chains with long-range interactions
We study the statistical properties of Ising spin chains with finite
(although arbitrary large) range of interaction between the elements. We
examine mesoscopic subsystems (fragments of an Ising chain) with the lengths
comparable with the interaction range. The equivalence of the Ising chains and
the multi-step Markov sequences is used for calculating different non-additive
statistical quantities of a chain and its fragments. In particular, we study
the variance of fluctuating magnetization of fragments, magnetization of the
chain in the external magnetic field, etc. Asymptotical expressions for the
non-additive energy and entropy of the mesoscopic fragments are derived in the
limiting cases of weak and strong interactions.Comment: 20 pages, 4 figure
Winds of Planet Hosting Stars
The field of exoplanetary science is one of the most rapidly growing areas of
astrophysical research. As more planets are discovered around other stars, new
techniques have been developed that have allowed astronomers to begin to
characterise them. Two of the most important factors in understanding the
evolution of these planets, and potentially determining whether they are
habitable, are the behaviour of the winds of the host star and the way in which
they interact with the planet. The purpose of this project is to reconstruct
the magnetic fields of planet hosting stars from spectropolarimetric
observations, and to use these magnetic field maps to inform simulations of the
stellar winds in those systems using the Block Adaptive Tree Solar-wind Roe
Upwind Scheme (BATS-R-US) code. The BATS-R-US code was originally written to
investigate the behaviour of the Solar wind, and so has been altered to be used
in the context of other stellar systems. These simulations will give
information about the velocity, pressure and density of the wind outward from
the host star. They will also allow us to determine what influence the winds
will have on the space weather environment of the planet. This paper presents
the preliminary results of these simulations for the star Bo\"otis,
using a newly reconstructed magnetic field map based on previously published
observations. These simulations show interesting structures in the wind
velocity around the star, consistent with the complex topology of its magnetic
field.Comment: 8 pages, 2 figures, accepted for publication in the peer-reviewed
proceedings of the 14th Australian Space Research Conference, held at the
University of South Australia, 29th September - 1st October 201
Socio-economic status over the life-course and depressive symptoms in men and women in Eastern Europe
Objective: Research into social inequalities in depression has studied western populations but data from non-western countries are sparse. In this paper, we investigate the extent of social inequalities in depression in Eastern Europe, the relative importance of social position at different points of the life-course, and whether social patterning of depression differs between men and women.Method: A cross-sectional study examined 12,053 men and 13,582 women in Russia, Poland and the Czech Republic. Depressive symptoms (16 or above on the CESD-20) were examined in relation to socio-economic circumstances at three phases of the life-course: childhood (household amenities and father's education); own education; current circumstances (financial difficulties and possession of household items).Results: Pronounced social differences in depression exist in men and women throughout Eastern Europe. Depression was largely influenced by current circumstances rather than by early life or education, with effects stronger in Poland and Russia. Odds ratios in men for current disadvantage were 3.16 [95% CI: 2.57-3.89], 3.16 [2.74-3.64] and 2.17 [1.80-2.63] in Russia, Poland and the Czech Republic respectively. Social variables did not explain the female excess in depression, which varied from 2.91 [2.58-3.27] in Russia to 1.90 [1.74-2.08] in Poland. Men were more affected by adult disadvantage than women, leading to narrower sex differentials in the presence of disadvantage.Limitations: Cross-sectional data with recall of childhood conditions were used.Conclusion: Current social circumstances are the strongest influence on increased depressive symptoms in countries which have recently experienced social changes. (C) 2007 Elsevier B.V. All rights reserved
Breaking of ergodicity and long relaxation times in systems with long-range interactions
The thermodynamic and dynamical properties of an Ising model with both short
range and long range, mean field like, interactions are studied within the
microcanonical ensemble. It is found that the relaxation time of
thermodynamically unstable states diverges logarithmically with system size.
This is in contrast with the case of short range interactions where this time
is finite. Moreover, at sufficiently low energies, gaps in the magnetization
interval may develop to which no microscopic configuration corresponds. As a
result, in local microcanonical dynamics the system cannot move across the gap,
leading to breaking of ergodicity even in finite systems. These are general
features of systems with long range interactions and are expected to be valid
even when the interaction is slowly decaying with distance.Comment: 4 pages, 5 figure
Duality Invariant Magnetohydrodynamics And Dyons
The theory of magnetohydrodynamics is extended to the cases of a plasma of
separate magnetic and electric charges, as well as to a plasma of dyons
respectively. In both these cases the system possesses electric-magnetic
duality symmetry. In the former case we find that because of the existence of
two independent generalized Ohm's law equations, the limit of infinite electric
and magnetic conductivity results in the vanishing of both electric and
magnetic fields, as well as the corresponding currents. In the dyonic case, we
find that the resulting duality-invariant system of equations are equivalent to
those of ordinary MHD, after suitable field redefinitions.Comment: 11 pages, late
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