7,972 research outputs found
E-business impacts for urban freight: results from an Australian study
E-Business is expected to dramatically change the way business is conducted internationally, nationally, within states and at the local area level. Moreover, these changes are very likely to happen well within the planning time frames required for provision of transport infrastructure and services. E-business is defined as including e-commerce, either between Businesses to Business (B2B) or Business to Customers (B2C), and the adoption of electronic technology within businesses. This paper presents some results from a study commissioned by the Australian National Transport Secretariat (NTS) to assist Australian business and government pro-actively address the transport issues arising from e-business. The resulting working papers will be used to establish a research framework for identifying policy and planning levers to maximize benefits to Australia from national and global e-business activity. The study sought to investigate three principal questions on e-business impacts: how will the transport task change; what will be affected; and how can the transport system respond? Current literature suggests that growth in e-business stems from the combined existence of market demand, suitable enabling technology, and skills and familiarity in management/users/ industry/government. The results of the study suggest that e-business will have implications for urban freight including higher levels of demand for goods and services, increased requirements for logistics distribution, changes in location preferences and improved transport network performance
Introducing the transport impacts of E-business project
E-Business is expected to dramatically change the way business is conducted internationally, nationally, within states and at the local area level. Moreover, these changes are very likely to happen well within the planning time frames required for provision of transport infrastructure and services. This paper introduces a study to investigate: how will the transport task change; what will be affected; and how can the transport system respond? The work, a joint initiative of the National Transport Secretariat [NTS], and the CSIRO/QUT Built Environment Research Alliance, in collaboration with Queensland Department of Public Works, is intended to assist Australian business and government pro-actively address the transport issues arising from e-business. E-commerce is growing exponentially: worldwide e-commerce revenues are estimated to reach $US1300 billion by 2003. Growth in electronic communications within companies which, together with e-commerce between companies, B2B, or between business and consumers, B2C, make up e-business, is even more significant. The magnitude and speed of both these changes increase the urgency of planning, for their impacts provide forecasting challenges. A study approach is described to consider direct impacts from e-business on Australian transport, derived demand for travel or delivery as other businesses prosper and transport related constraints to e-business in the next five to ten years. Base line information collection: includes a review of literature and information about trends in e-business then transport and e-Business; interviews with stakeholder/experts in planning agencies, e-business companies and transport/logistics firms across Australia; appraisal of data available for on-going assessment; and contact with international experts. Trends and impact assessment: National trends will be estimated and very important impacts or very urgent impacts selected via a ranking and rating process. Transport related productivity gains will be assessed; trends in regional Australia and international trends and experience will be reported with a final assessment of opportunities and threats for Australia. Outputs: A series of working papers and final reports; a user friendly database of contacts, publications and data availability information for update; a research framework for identification of policy and planning levers to maximise benefits to Australia from national and global e-business activity
On the scaling of the damping time for resonantly damped oscillations in coronal loops
There is not as yet full agreement on the mechanism that causes the rapid
damping of the oscillations observed by TRACE in coronal loops. It has been
suggested that the variation of the observed values of the damping time as
function of the corresponding observed values of the period contains
information on the possible damping mechanism. The aim of this Letter is to
show that, for resonant absorption, this is definitely not the case unless
detailed a priori information on the individual loops is available
Soil carbon sequestration rates under Mediterranean woody crops using recommended management practices : A meta-analysis
This work was supported by the projects: CARBOLIVAR (P11-RNM-7186) funded by Consejería de Innovación, Ciencia y Empresa of Junta de Andalucía and GEISpain project (CGL2014‐52838‐C2‐1‐R) funded by Ministerio de Economía y Competitividad, both including European Union ERDF funds. This work was also supported by the FPU 2012 grant program of the Ministerio de Educación, Cultura y Deporte of Spain. Dr. Roberto Garcia-Ruiz and Eduardo Aguilera gratefully acknowledge support by the Sustainable Farm Systems project (SSHRC 895-2011-1020) funded by the Canadian Social Sciences and Humanities Research Council.Peer reviewedPostprin
Algebraic and combinatorial aspects of sandpile monoids on directed graphs
The sandpile group of a graph is a well-studied object that combines ideas
from algebraic graph theory, group theory, dynamical systems, and statistical
physics. A graph's sandpile group is part of a larger algebraic structure on
the graph, known as its sandpile monoid. Most of the work on sandpiles so far
has focused on the sandpile group rather than the sandpile monoid of a graph,
and has also assumed the underlying graph to be undirected. A notable exception
is the recent work of Babai and Toumpakari, which builds up the theory of
sandpile monoids on directed graphs from scratch and provides many connections
between the combinatorics of a graph and the algebraic aspects of its sandpile
monoid.
In this paper we primarily consider sandpile monoids on directed graphs, and
we extend the existing theory in four main ways. First, we give a combinatorial
classification of the maximal subgroups of a sandpile monoid on a directed
graph in terms of the sandpile groups of certain easily-identifiable subgraphs.
Second, we point out certain sandpile results for undirected graphs that are
really results for sandpile monoids on directed graphs that contain exactly two
idempotents. Third, we give a new algebraic constraint that sandpile monoids
must satisfy and exhibit two infinite families of monoids that cannot be
realized as sandpile monoids on any graph. Finally, we give an explicit
combinatorial description of the sandpile group identity for every graph in a
family of directed graphs which generalizes the family of (undirected)
distance-regular graphs. This family includes many other graphs of interest,
including iterated wheels, regular trees, and regular tournaments.Comment: v2: Cleaner presentation, new results in final section. Accepted for
publication in J. Combin. Theory Ser. A. 21 pages, 5 figure
The generic mapping tools version 6
The Generic Mapping Tools (GMT) software is ubiquitous in the Earth and ocean sciences. As a cross-platform tool producing high-quality maps and figures, it is used by tens of thousands of scientists around the world. The basic syntax of GMT scripts has evolved very slowly since the 1990s, despite the fact that GMT is generally perceived to have a steep learning curve with many pitfalls for beginners and experienced users alike. Reducing these pitfalls means changing the interface, which would break compatibility with thousands of existing scripts. With the latest GMT version 6, we solve this conundrum by introducing a new "modern mode" to complement the interface used in previous versions, which GMT 6 now calls "classic mode." GMT 6 defaults to classic mode and thus is a recommended upgrade for all GMT 5 users. Nonetheless, new users should take advantage of modern mode to make shorter scripts, quickly access commonly used global data sets, and take full advantage of the new tools to draw subplots, place insets, and create animations.Funding Agency
National Science Foundation (NSF)
Appeared in article as
U.S. National Science Foundation
MSU Geological Sciences Endowmentinfo:eu-repo/semantics/publishedVersio
Prediction-based classification for longitudinal biomarkers
Assessment of circulating CD4 count change over time in HIV-infected subjects
on antiretroviral therapy (ART) is a central component of disease monitoring.
The increasing number of HIV-infected subjects starting therapy and the limited
capacity to support CD4 count testing within resource-limited settings have
fueled interest in identifying correlates of CD4 count change such as total
lymphocyte count, among others. The application of modeling techniques will be
essential to this endeavor due to the typically nonlinear CD4 trajectory over
time and the multiple input variables necessary for capturing CD4 variability.
We propose a prediction-based classification approach that involves first stage
modeling and subsequent classification based on clinically meaningful
thresholds. This approach draws on existing analytical methods described in the
receiver operating characteristic curve literature while presenting an
extension for handling a continuous outcome. Application of this method to an
independent test sample results in greater than 98% positive predictive value
for CD4 count change. The prediction algorithm is derived based on a cohort of
HIV-1 infected individuals from the Royal Free Hospital, London who
were followed for up to three years from initiation of ART. A test sample
comprised of individuals from Philadelphia and followed for a similar
length of time is used for validation. Results suggest that this approach may
be a useful tool for prioritizing limited laboratory resources for CD4 testing
after subjects start antiretroviral therapy.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS326 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
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