194 research outputs found
Briefing: Resource scarcity and resource security – a suppressed civil engineering challenge
While natural and manufactured resources provide the raw materials with which civil engineers work, the term ‘resources’ should always be considered in its wider interpretation and then in the context that resources are in many cases limited. That they should be used wisely (resource efficiency) is beyond contention – we do this as a matter of course – yet considerations of where and how resources are obtained and refined for use are far less likely to feature in a civil engineer's psyche. Similarly, considerations of resource availability for others now, and importantly in the future, and the vulnerability of these resources to future supply disruption (e.g. for geopolitical reasons) are likely not to be in the forefront of our thinking when conducting our routine business. The ICE Research, Development & Innovation towards Engineering Excellence panel has chosen this topic as one of pressing importance across all the sectors that comprise civil engineering. Accordingly, the panel is promoting this topic for Research & Development Enabling Fund (R&DEF) proposals. This briefing note describes the prior work of the panel in exploring the extent of this issue, along with insights from current research, to raise awareness, encourage R&DEF proposals and prime debates on this topic
A Composite Resilience Index for Road Transport Networks
This paper is concerned with the development of a composite index for the resilience of road transport networks under disruptive events. The index employs three resilience characteristics, namely redundancy, vulnerability and mobility. Two different approaches, i.e. equal weighting and principal component analysis, are adopted to
conduct the aggregation. In addition, the impact of the availability of real-time travel
information for travellers on the three resilience characteristics and the composite resilience index is described. The application of the index on a synthetic road transport network of Delft city
(Netherlands) shows that it responds well to traffic load changes and supply variations.
The composite resilience index could be of use in various ways including supporting decision makers in understanding the dynamic nature of resilience under different disruptive events, highlighting weaknesses in the network and in assisting future
planning to mitigate the impacts of disruptive events
A decision support system to proactively manage subsurface utilities
Critical infrastructure assets are defined in terms of their purpose (e.g. roads, water, and energy) yet the ground, which supports these assets, can also be considered a critical asset leading to the conclusion that any assessment of critical infrastructure must consider the ground in that assessment. While the interdependency of critical infrastructures is recognised, the consequences of failing to recognise the ground as an asset can lead to failure of the infrastructure it supports. This motivates the need for a decision support system for subsurface utilities that takes into account the surrounding ground and the overlying road structure. These facilities mostly exist in an urban environment. The ground supports the road and the underlying utility which means the failure of any of these assets (road, ground, or utility) can trigger a failure in the others, the most extreme example being the collapse of roads due to erosion of the supporting ground by a leaking pipe. This paper describes the principles that underpin a novel decision support system for those engaged in street works of any kind, and how a multidisciplinary approach is being used to create a practical toolkit to reduce risk and minimise disruption to proactively manage subsurface utilities using site observations and investigations, public and private databases, expert opinions captured in a number of ontologies and an inference engine to produce guidance that takes into account risk and sustainability criteria
Do we need to rethink our waterways? Values of ageing waterways in current and future society
In the past canals were developed, and some rivers were heavily altered, driven by the need for good transportation infrastructure. Major investments were made in navigation locks, weirs and artificial embankments, and many of these assets are now reaching the end of their technical lifetime. Since then the concept of integrated water resource management (IWRM) emerged as a concept to manage and develop water-bodies in general. Two pressing problems arise from these developments: (1) major reinvestment is needed in order to maintain the transportation function of these waterways, and (2), it is not clear how the implementation of the concept of IWRM can be brought into harmony with such reinvestment. This paper aims to illustrate the problems in capital-intensive parts of waterway systems, and argues for exploring value-driven solutions that rely on the inclusion of multiple values, thus solving both funding problems and stakeholder conflicts. The focus on value in cooperative strategies is key to defining viable implementation strategies for waterway projects
Appraising infrastructure for new towns in Ireland
Copyright © 2013 ICE Publishing Ltd. Permission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees.Over a 20 year period 1996–2016, a new 223 ha town is being developed 10 miles west of Dublin's city centre on the south side of Lucan, County Dublin, in the Republic of Ireland (ROI). This €4 billion ‘Adamstown’ development is the first of four planning schemes in ROI to be approved as a strategic development zone – an integrated planning framework deemed suitable for creating sustainable neighbourhoods in sites of strategic economic or social importance to the state. The creation of sustainable neighbourhoods in ROI is facilitated through the implementation of a checklist of 60 indicators. This paper critically examines the attempts being made to consider sustainability within the development's overall infrastructure plan, specifically: transport, energy and water services, information technology and waste. Inadequacies in the existing development are linked to shortfalls in the sustainability checklist, by way of a comparison of infrastructure-related indicators from the ROI checklist with those derived for the UK and exemplar European projects (i.e. Bedzed, UK and Freiberg, Germany). The subsequent legacy for future residents of Adamstown is then considered in the context of ‘what if’ scenarios
Measurement of the Cross Section and Triple Gauge Couplings in Collisions at TeV
This Letter describes the current most precise measurement of the
production cross section as well as limits on anomalous couplings at a
center-of-mass energy of 1.96 TeV in proton-antiproton collisions for the
Collider Detector at Fermilab (CDF). candidates are reconstructed from
decays containing three charged leptons and missing energy from a neutrino,
where the charged leptons are either electrons or muons. Using data collected
by the CDF II detector (7.1 fb of integrated luminosity), 63 candidate
events are observed with the expected background contributing events.
The measured total cross section pb is in good
agreement with the standard model prediction of . The same sample
is used to set limits on anomalous couplings.Comment: Resubmission to PRD-RC after acceptance (27 July 2012
Precision measurement of the top quark mass from dilepton events at CDF II
We report a measurement of the top quark mass, M_t, in the dilepton decay
channel of
using an integrated luminosity of 1.0 fb^{-1} of p\bar{p} collisions collected
with the CDF II detector. We apply a method that convolutes a leading-order
matrix element with detector resolution functions to form event-by-event
likelihoods; we have enhanced the leading-order description to describe the
effects of initial-state radiation. The joint likelihood is the product of the
likelihoods from 78 candidate events in this sample, which yields a measurement
of M_{t} = 164.5 \pm 3.9(\textrm{stat.}) \pm 3.9(\textrm{syst.})
\mathrm{GeV}/c^2, the most precise measurement of M_t in the dilepton channel.Comment: 7 pages, 2 figures, version includes changes made prior to
publication by journa
Measurement of the Ratios of Branching Fractions B(Bs -> Ds pi pi pi) / B(Bd -> Dd pi pi pi) and B(Bs -> Ds pi) / B(Bd -> Dd pi)
Using 355 pb^-1 of data collected by the CDF II detector in \ppbar collisions
at sqrt{s} = 1.96 TeV at the Fermilab Tevatron, we study the fully
reconstructed hadronic decays B -> D pi and B -> D pi pi pi. We present the
first measurement of the ratio of branching fractions B(Bs -> Ds pi pi pi) /
B(Bd -> Dd pi pi pi) = 1.05 pm 0.10 (stat) pm 0.22 (syst). We also update our
measurement of B(Bs -> Ds pi) / B(Bd -> Dd pi) to 1.13 pm 0.08 (stat) pm 0.23
(syst) improving the statistical uncertainty by more than a factor of two. We
find B(Bs -> Ds pi) = [3.8 pm 0.3 (stat) pm 1.3 (syst)] \times 10^{-3} and B(Bs
-> Ds pi pi pi) = [8.4 pm 0.8 (stat) pm 3.2 (syst)] \times 10^{-3}.Comment: 7 pages, 2 figure
Cross Section Measurements of High- Dilepton Final-State Processes Using a Global Fitting Method
We present a new method for studying high- dilepton events
(, , ) and simultaneously
extracting the production cross sections of , , and p\bar{p} \to \ztt at a center-of-mass energy of TeV. We perform a likelihood fit to the dilepton data in a parameter
space defined by the missing transverse energy and the number of jets in the
event. Our results, which use of data recorded with the CDF
II detector at the Fermilab Tevatron Collider, are pb, pb, and
\sigma(\ztt) =291^{+50}_{-46} pb.Comment: 20 pages, 2 figures, to be submitted to PRD-R
Top Quark Mass Measurement from Dilepton Events at CDF II with the Matrix-Element Method
We describe a measurement of the top quark mass using events with two charged
leptons collected by the CDF II detector from collisions with TeV at the Fermilab Tevatron. The likelihood in top mass is
calculated for each event by convoluting the leading order matrix element
describing
with detector resolution functions. The presence of background events in the
data sample is modeled using similar calculations involving the matrix elements
for major background processes. In a data sample with integrated luminosity of
340 pb, we observe 33 candidate events and measure This
measurement represents the first application of this method to events with two
charged leptons and is the most precise single measurement of the top quark
mass in this channel.Comment: 21 pages, 14 figure
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