22,019 research outputs found
Systems Analysis as a Decision-Making Tool for the Library Manager
published or submitted for publicatio
Middle-atmospheric response to a future increase in humidity arising from increased methane abundance
On the Sequential Choice of Tradable Permit Allocations
This paper investigates the sequential announcement of domestic emissions caps by regulators in a federal or international-based tradable pollution permit market for a transboundary pollutant. A leader-follower framework is used to analyse the consequences of regulators sequentially announcing domestic allocation caps. We find the sequential choice of domestic allocation caps is sub-optimal and depends on the follower's reaction to the leader's choice. Furthermore, the marginal damage and the degree to which allocations are substitutes or complements affects whether the leader changes from being a net permit buyer (seller) of permits to a seller (buyer).Initial allocation, international tradable permit market, leader-follower
Controlling externalities in the presence of rent seeking
Contests are a common method to describe the distribution of many different types of rents. Yet in many of these situations the utilisation of the prize plays an important role in determining agents payoffs and incentives. In this paper, we investigate the incentives to expend effort for a prize that produces consumption externalities and consider alternative regulatory policies. We find relatively more global consumption externalities will increase (decrease) rent seeking when con- sumption externalities are negative (positive). We show how introducing Pigouvian taxation (possibly with revenue transfer) and Coasean bargaining alters equilib- rium effort and payoffs. Pigouvian taxation tends to reduce both effort and payoffs whereas this is not always the case for Coasean bargaining. In the presence of suf- ficiently large consumption externalities, establishing Pigouvian taxation coupled with some element of lump-sum transfer may reduce costly rent seeking effort and improve the welfare of some agents compared to other approaches.externalities, contest, natural resources
Holistic finite differences accurately model the dynamics of the Kuramoto-Sivashinsky equation
We analyse the nonlinear Kuramoto-Sivashinsky equation to develop an accurate
finite difference approximation to its dynamics. The analysis is based upon
centre manifold theory so we are assured that the finite difference model
accurately models the dynamics and may be constructed systematically. The
theory is applied after dividing the physical domain into small elements by
introducing insulating internal boundaries which are later removed. The
Kuramoto-Sivashinsky equation is used as an example to show how holistic finite
differences may be applied to fourth order, nonlinear, spatio-temporal
dynamical systems. This novel centre manifold approach is holistic in the sense
that it treats the dynamical equations as a whole, not just as the sum of
separate terms
Accurately model the Kuramoto--Sivashinsky dynamics with holistic discretisation
We analyse the nonlinear Kuramoto--Sivashinsky equation to develop accurate
discretisations modeling its dynamics on coarse grids. The analysis is based
upon centre manifold theory so we are assured that the discretisation
accurately models the dynamics and may be constructed systematically. The
theory is applied after dividing the physical domain into small elements by
introducing isolating internal boundaries which are later removed.
Comprehensive numerical solutions and simulations show that the holistic
discretisations excellently reproduce the steady states and the dynamics of the
Kuramoto--Sivashinsky equation. The Kuramoto--Sivashinsky equation is used as
an example to show how holistic discretisation may be successfully applied to
fourth order, nonlinear, spatio-temporal dynamical systems. This novel centre
manifold approach is holistic in the sense that it treats the dynamical
equations as a whole, not just as the sum of separate terms.Comment: Without figures. See
http://www.sci.usq.edu.au/staff/aroberts/ksdoc.pdf to download a version with
the figure
Gill Ventilation Rates of Mayfly Nymphs (Ephemeroptera: Heptageniidae) as a Biomonitoring Technique
Gill ventilation frequency (GVF) of the mayfly nymph Stenacron interpunctatum (Ephemeroptera: Heptageniidae) was studied to assess the applicability of a relatively simple, real time video methodology and to assess the potential of GVF rates for use in a chronic assay of sediment pore water. Stenacron interpunctatum nymphs were exposed to pore water samples taken along a transect from the mouth of the Fox River to Sturgeon Bay in the Green Bay area of Lake Michigan. This transect has previously been shown to exhibit several distinct gradients in sediment and water column conditions with distance from the Fox River. The highest GVF value of 6.68 ± 0.27 Hz was observed in pore water from the more polluted area near the Fox River. A lower GVF value of 5.44 ± 0.32 Hz was observed in pore water from the station near Sturgeon Bay and of 4.25 ± 0.27 Hz from the cleaner Lake Michigan station. GVF values exhibited a decreasing trend with relative distance from the mouth of the Fox River (r2 = 0.76)
A Preservative-Free Emergent Trap for the Isotopic and Elemental Analysis of Emergent Insects From a Wetland System
This study reports a cost-effective, live emergent trap designed for the preservative-free use in both biogeochemical and ecological analyses of emerging insects. The trap proved to be advantageous in several ways. First, the simple design made the trap time-efficient since it was easy to set-up, change, and maintain. Second, live sampling not only provided uncontaminated organisms for elemental and stable isotopic analyses, it minimized disfigurement. This resulted in rapid and easy handling, as well as identification, of adult insects. Finally, trap avoidance by ephemeropterans and odonates, a common problem encountered in the literature, was minimal and organisms from both insect orders were successfully collected
An efficient counter-based broadcast scheme for mobile ad hoc networks
In mobile ad hoc networks (MANETs), broadcasting plays a fundamental role, diffusing a message from a given source node to all the other nodes in the network. Flooding is the simplest and commonly used mechanism for broadcasting in MANETs, where each node retransmits every uniquely received message exactly once. Despite its simplicity, it however generates redundant rebroadcast messages which results in high contention and collision in the network, a phenomenon referred to as broadcast storm problem. Pure probabilistic approaches have been proposed to mitigate this problem inherent with flooding, where mobile nodes rebroadcast a message with a probability p which can be fixed or computed based on the local density. However, these approaches reduce the number of rebroadcasts at the expense of reachability. On the other hand, counter-based approaches inhibit a node from broadcasting a packet based on the number of copies of the broadcast packet received by the node within a random access delay time. These schemes achieve better throughput and reachability, but suffer from relatively longer delay. In this paper, we propose an efficient broadcasting scheme that combines the advantages of pure probabilistic and counter-based schemes to yield a significant performance improvement. Simulation results reveal that the new scheme achieves superior performance in terms of saved-rebroadcast, reachability and latency
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