9,269 research outputs found
Sustainability best practice in PPP: Case study of a hospital project in the UK
Globally, sustainable development has been given high priority for the Government agenda in order to achieve a balance of social, economic and environmental factors. The UK government realise the importance and criticality of sustainable development and they intend to use the public procurement power to demand more sustainable public building development to improve energy efficiency and reduce carbon emissions. Public Private Partnership (PPP) is an effective procurement tool for the government to deliver the provision of public services. In the UK, the most common PPP form is Private Finance Initiative (PFI). Up until March 2012, a total of 717 PFI projects have been delivered to sustain social and economic development in the UK (HM Treasury, 2012). There is potential to use PPP to incorporate the sustainability agenda and support low carbon economic development. However, little research has been conducted to demonstrate the benefits and advantages of the PPP procurement system incorporating sustainable development. This paper aims to demonstrate best practice in sustainable development through PPP (PFI) procurement system in the UK. It initially illustrates the relationship between PPP and sustainable development and then uses a case study of one of the largest PPP hospital projects in the UK, utilising interviews and secondary data to show evidence of how the sustainability issues have been addressed within the procurement process and the advantage and limitations of using the PPP procurement system in delivering sustainable development. The results show best practice across different strands of sustainability through contribution to local employment and the local economy, a high percentage of waste recycling, dust and noise reduction and technical innovations such as green roofs, natural ventilation and a focus on occupant comfort
Graded, Dynamically Routable Information Processing with Synfire-Gated Synfire Chains
Coherent neural spiking and local field potentials are believed to be
signatures of the binding and transfer of information in the brain. Coherent
activity has now been measured experimentally in many regions of mammalian
cortex. Synfire chains are one of the main theoretical constructs that have
been appealed to to describe coherent spiking phenomena. However, for some
time, it has been known that synchronous activity in feedforward networks
asymptotically either approaches an attractor with fixed waveform and
amplitude, or fails to propagate. This has limited their ability to explain
graded neuronal responses. Recently, we have shown that pulse-gated synfire
chains are capable of propagating graded information coded in mean population
current or firing rate amplitudes. In particular, we showed that it is possible
to use one synfire chain to provide gating pulses and a second, pulse-gated
synfire chain to propagate graded information. We called these circuits
synfire-gated synfire chains (SGSCs). Here, we present SGSCs in which graded
information can rapidly cascade through a neural circuit, and show a
correspondence between this type of transfer and a mean-field model in which
gating pulses overlap in time. We show that SGSCs are robust in the presence of
variability in population size, pulse timing and synaptic strength. Finally, we
demonstrate the computational capabilities of SGSC-based information coding by
implementing a self-contained, spike-based, modular neural circuit that is
triggered by, then reads in streaming input, processes the input, then makes a
decision based on the processed information and shuts itself down
Visual Chunking: A List Prediction Framework for Region-Based Object Detection
We consider detecting objects in an image by iteratively selecting from a set
of arbitrarily shaped candidate regions. Our generic approach, which we term
visual chunking, reasons about the locations of multiple object instances in an
image while expressively describing object boundaries. We design an
optimization criterion for measuring the performance of a list of such
detections as a natural extension to a common per-instance metric. We present
an efficient algorithm with provable performance for building a high-quality
list of detections from any candidate set of region-based proposals. We also
develop a simple class-specific algorithm to generate a candidate region
instance in near-linear time in the number of low-level superpixels that
outperforms other region generating methods. In order to make predictions on
novel images at testing time without access to ground truth, we develop
learning approaches to emulate these algorithms' behaviors. We demonstrate that
our new approach outperforms sophisticated baselines on benchmark datasets.Comment: to appear at ICRA 201
The limit of massive gravity
Lorentz-invariant massive gravity is usually associated with a strong
coupling scale . By including non-trivial effects from the
Stueckelberg modes, we show that about these vacua, one can push the strong
coupling scale to higher values and evade the linear vDVZ-discontinuity. For
generic parameters of the theory and generic vacua for the Stueckelberg fields,
the -decoupling limit of the theory is well-behaved and free of any
ghost or gradient-like instabilities. We also discuss the implications for
nonlinear sigma models with Lorentzian target spaces.Comment: 38 pages, 1 figure, JHEP version, minor change
Casimir Meets Poisson: Improved Quark/Gluon Discrimination with Counting Observables
Charged track multiplicity is among the most powerful observables for
discriminating quark- from gluon-initiated jets. Despite its utility, it is not
infrared and collinear (IRC) safe, so perturbative calculations are limited to
studying the energy evolution of multiplicity moments. While IRC-safe
observables, like jet mass, are perturbatively calculable, their distributions
often exhibit Casimir scaling, such that their quark/gluon discrimination power
is limited by the ratio of quark to gluon color factors. In this paper, we
introduce new IRC-safe counting observables whose discrimination performance
exceeds that of jet mass and approaches that of track multiplicity. The key
observation is that track multiplicity is approximately Poisson distributed,
with more suppressed tails than the Sudakov peak structure from jet mass. By
using an iterated version of the soft drop jet grooming algorithm, we can
define a "soft drop multiplicity" which is Poisson distributed at
leading-logarithmic accuracy. In addition, we calculate the
next-to-leading-logarithmic corrections to this Poisson structure. If we allow
the soft drop groomer to proceed to the end of the jet branching history, we
can define a collinear-unsafe (but still infrared-safe) counting observable.
Exploiting the universality of the collinear limit, we define generalized
fragmentation functions to study the perturbative energy evolution of
collinear-unsafe multiplicity.Comment: 38+10 pages, 21 figures; v2: discussions added to match JHEP versio
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