University of Exeter

About: University of Exeter is a education organization based out in Exeter, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 15820 authors who have published 50650 publications receiving 1793046 citations. The organization is also known as: Exeter University & University of the South West of England.

Pressure-Driven Demand and Leakage Simulation for Water Distribution Networks

Abstract: Increasingly, water loss via leakage is acknowledged as one of the main challenges facing water distribution system operations. The consideration of water loss over time, as systems age, physical networks grow, and consumption patterns mature, should form an integral part of effective asset management, rendering any simulation model capable of quantifying pressure-driven leakage indispensable. To this end, a novel steady-state network simulation model that fully integrates into a classical hydraulic representation, pressure-driven demand and leakage at the pipe level is developed and presented here. After presenting a brief literature review about leakage modeling, the importance of a more realistic simulation model allowing for leakage analysis is demonstrated. The algorithm is then tested from a numerical standpoint and subjected to a convergence analysis. These analyses are performed on a case study involving two networks derived from real systems. Experimentally observed convergence/error statistics demonstrate the high robustness of the proposed pressure-driven demand and leakage simulation model.

Breaking the frame: an analysis of strategic cognition and decision making under uncertainty

Abstract: This paper reports the findings of two experimental investigations into the efficacy of a causal cognitive mapping procedure as a means for overcoming cognitive biases arising from the framing of strategic decision problems In Study 1, final year management studies undergraduate students were presented with an elaborated strategic decision scenario, under one of four experimental conditions: positively vs negatively framed decision scenarios, with prechoice vs postchoice mapping task orders (ie, participants were required to engage in cognitive mapping before or after making a decision) As predicted, participants in the postchoice mapping conditions succumbed to the framing bias whereas those in the prechoice mapping conditions did not Study 2 replicated and extended these findings in a field setting, on a sample of senior managers, using a decision scenario that closely mirrored a strategic dilemma currently facing their organization Taken together, the findings of these studies indicate that the framing bias is likely to be an important factor in strategic decision making, and suggest that cognitive mapping provides an effective means of limiting the damage accruing from this bias Copyright © 1999 John Wiley & Sons, Ltd

The future that may (or may not) come: How framing changes responses to uncertainty in climate change communications

Abstract: Communicating possible effects of climate change inevitably involves uncertainty Because people are generally averse to uncertainty, this activity has the potential to undermine effective action more than stimulate it The present research considered how framing climate change predictions differently might moderate the tendency for uncertainty to undermine individual action Two studies ( N s = 88 and 120) show that higher uncertainty combined with a negative frame (highlighting possible losses) decreased individual intentions to behave environmentally However when higher uncertainty was combined with a positive frame (highlighting the possibility of losses not materializing) this produced stronger intentions to act Study 2 revealed that these effects of uncertainty were mediated through feelings of efficacy These results suggest that uncertainty is not an inevitable barrier to action, provided communicators frame climate change messages in ways that trigger caution in the face of uncertainty

Accessing the transport properties of graphene and its multilayers at high carrier density

Abstract: We present a comparative study of high carrier density transport in mono-, bi-, and trilayer graphene using electric double-layer transistors to continuously tune the carrier density up to values exceeding 10(14) cm(-2). Whereas in monolayer the conductivity saturates, in bi- and trilayer filling of the higher-energy bands is observed to cause a nonmonotonic behavior of the conductivity and a large increase in the quantum capacitance. These systematic trends not only show how the intrinsic high-density transport properties of graphene can be accessed by field effect, but also demonstrate the robustness of ion-gated graphene, which is crucial for possible future applications.

Fictitious Inhibitory Differences How Skewness and Slowing Distort the Estimation of Stopping Latencies

Abstract: The stop-signal paradigm is a popular method for examining response inhibition and impulse control in psychology, cognitive neuroscience, and clinical domains because it allows the estimation of the covert latency of the stop process: the stop-signal reaction time (SSRT). In three sets of simulations, we examined to what extent SSRTs that were estimated with the popular mean and integration methods were influenced by the skew of the reaction time distribution and the gradual slowing of the response latencies. We found that the mean method consistently overestimated SSRT. The integration method tended to underestimate SSRT when response latencies gradually increased. This underestimation bias was absent when SSRTs were estimated with the integration method for smaller blocks of trials. Thus, skewing and response slowing can lead to spurious inhibitory differences. We recommend that the mean method of estimating SSRT be abandoned in favor of the integration method.