Do personality traits predict post-traumatic stress?: a prospective study in civilians experiencing air attacks

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Economic performance of DMAs in water distribution systems

This is the final version of the article. Available from the publisher via the DOI in this record.© 2015 Published by Elsevier Ltd. An effective implementation of District Metered Areas (DMAs) in water distribution systems requires the analysis and cost comparison of various feasible solutions, which differ both in the number and the boundaries of the districts and provide different levels of benefits. The evaluation of the benefits provided by alternative DMA layouts (in terms of reduction of leakage, burst frequency, water and energy consumption) allows practitioners to make sensible decisions and create functional and efficient DMAs. This paper shows an analysis of the costs and benefits following the introduction of DMAs to water distribution systems, providing a framework for assessing the economic performance of DMAs, comparing different possible DMA layouts, and identifying the best solution among different options. A real water distribution network is considered as a case study, various DMA layouts are identified and ranked on the basis of the total benefit provided

Finance pathways for young innovative small‐ and medium‐size enterprises: a demand‐side examination of finance gaps and policy implications for the post‐global financial crisis finance escalator

The paper addresses the persistent finance gaps facing young, innovative SMEs, by examining the financing pathways of 40 UK businesses in a post global financial crisis (GFC) environment. Using a unique combination of finance escalator and resource-based view theories four propositions are tested by examining: (i) early and growth stage development; (ii) innovation R&D investment horizons; (iii) the management resource base; (iv) finance gaps and their implications. The paper finds that successful financing strategies are emerging, using a mix of bootstrapping, collaboration and new emerging post-GFC finance escalator funding, which is heavily reliant on government interventions. It also pinpoints remaining finance gaps and the need for more cohesive financing and support policy to address these

Dilute magnetic semiconductor quantum-well structures for magnetic field tunable far-infrared/terahertz absorption

The design of ZnCdSe–ZnMnSe-based quantum wells is considered, in order to obtain a large shift of the peak absorption wavelength in the far infrared range, due to a giant Zeeman splitting with magnetic field, while maintaining a reasonably large value of peak absorption. A triple quantum-well structure with a suitable choice of parameters has been found to satisfy such requirements. A maximal tuning range between 14.6 and 34.7 meV is obtained, when the magnetic field varies from zero to 5 T, so the wavelength of the absorbed radiation decreases from 85.2 to 35.7 μm with absorption up to 1.25% at low temperatures. These structures might form the basis for magnetic field tunable photodetectors and quantum cascade lasers in the terahertz range

Urban hydroinformatics: past, present and future

This is the author accepted manuscriptHydroinformatics, as an interdisciplinary domain that blurs boundaries between water science, data science and computer science, is constantly evolving and reinventing itself. At the heart of this evolution, lies a continuous process of critical (self) appraisal of the discipline’s past, present and potential for further evolution, that creates a positive feedback loop between legacy, reality and aspirations. The power of this process is attested by the successful story of hydroinformatics thus far, which has arguably been able to mobilize wide ranging research and development and get the water sector more in tune with the digital revolution of the past 30 years. In this context, this paper attempts to trace the evolution of the discipline, from its computational hydraulics origins to its present focus on the complete socio-technical system, by providing at the same time, a functional framework to improve the understanding and highlight the links between different strands of the state-of-art hydroinformatic research and innovation. Building on this state-of-art landscape, the paper then attempts to provide an overview of key developments that are coming up, on the discipline’s horizon, focusing on developments relevant to urban water management, while at the same time, highlighting important legal, ethical and technical challenges that need to be addressed to ensure that the brightest aspects of this potential future are realized. Despite obvious limitations imposed by a single paper’s ability to report on such a diverse and dynamic field, it is hoped that this work contributes to a better understanding of both the current state of hydroinformatics and to a shared vision on the most exciting prospects for the future evolution of the discipline and the water sector it serves

Magnetic field tunable terahertz quantum well infrared photodetector

A theoretical model and a design of a magnetic field tunable CdMnTe/CdMgTe terahertz quantum well infrared photodetector are presented. The energy levels and the corresponding wavefunctions were computed from the envelope function Schr¨odinger equation using the effective mass approximation and accounting for Landau quantization and the giant Zeeman effect induced by magnetic confinement. The electron dynamics were modeled within the self-consistent coupled rate equations approach, with all relevant electron-longitudinal optical phonon and electron-longitudinal acoustic phonon scattering included. A perpendicular magnetic field varying between 0 T and 5 T, at a temperature of 1.5 K, was found to enable a large shift of the detection energy, yielding a tuning range between 24.1 meV and 34.3 meV, equivalent to 51.4 μm to 36.1 μm wavelengths. For magnetic fields between 1 T and 5 T, when the electron population of the QWIP is spin-polarized, a reasonably low dark current of ≤1.4×10–² A/cm² and a large responsivity of 0.36−0.64 A/W are predicted

Interactive 3D visualisation of optimisation for water distribution systems

Session S6-03, Special Session: Evolutionary Computing in Water Resources Planning and Management IIIThis project investigates the use of modern 3D visualisation techniques to enable the interactive analysis of water distribution systems with the aim of providing the engineer with a clear picture of the problem and thus aid the overall design process. Water distribution systems are complex entities that are difficult to model and optimise as they consist of many interacting components each with a set of considerations to address, hence it is important for the engineer to understand and assess the behaviour of the system to enable its effective design and optimisation. This paper presents a new three-dimensional representation of pipe based water systems and demonstrates a range of innovative methods to convey information to the user. The system presented not only allows the engineer to visualise the various parameters of a network but also allows the user to observe the behaviour and progress of an iterative optimisation method. This paper contains examples of the combination of the interactive visualisation system and an evolutionary algorithm enabling the user to track and visualise the actions of the algorithm down to an individual pipe diameter change. It is proposed that this interactive visualisation system will provide engineers an unprecedented view of the way in which optimisation algorithms interact with a network model and may pave the way for greater interaction between engineer, network and optimiser in the futur

Multi-objective pipe smoothing genetic algorithm for water distribution network design

Session S6-03, Special Session: Evolutionary Computing in Water Resources Planning and Management IIIThis paper describes the formulation of a Multi-objective Pipe Smoothing Genetic Algorithm (MOPSGA) and its application to the least cost water distribution network design problem. Evolutionary Algorithms have been widely utilised for the optimisation of both theoretical and real-world non-linear optimisation problems, including water system design and maintenance problems. In this work we present a pipe smoothing based approach to the creation and mutation of chromosomes which utilises engineering expertise with the view to increasing the performance of the algorithm whilst promoting engineering feasibility within the population of solutions. MOPSGA is based upon the standard Non-dominated Sorting Genetic Algorithm-II (NSGA-II) and incorporates a modified population initialiser and mutation operator which directly targets elements of a network with the aim to increase network smoothness (in terms of progression from one diameter to the next) using network element awareness and an elementary heuristic. The pipe smoothing heuristic used in this algorithm is based upon a fundamental principle employed by water system engineers when designing water distribution pipe networks where the diameter of any pipe is never greater than the sum of the diameters of the pipes directly upstream resulting in the transition from large to small diameters from source to the extremities of the network. MOPSGA is assessed on a number of water distribution network benchmarks from the literature including some real-world based, large scale systems. The performance of MOPSGA is directly compared to that of NSGA-II with regard to solution quality, engineering feasibility (network smoothness) and computational efficiency. MOPSGA is shown to promote both engineering and hydraulic feasibility whilst attaining good infrastructure costs compared to NSGA-II

Development of a leakage target setting approach for South Korea based on Economic Level of Leakage

Published13th Computer Control for Water Industry Conference, CCWI 2015Leakage has become a crucial issue that needs to be addressed effectively by water suppliers in terms of economic management of water systems. A target setting method based on the ELL (Economic Level of Leakage) calculation is proposed in this paper. The methodology applied is developed specifically for the South Korean context to select a minimum achievable level of NRW (Non-Revenue Water) and verify the appropriateness of the current target within existing financial constraints by using limited available data. This approach is focused on the derivation of the NRW control cost curve by using the newly developed cumulative method that minimizes data fluctuation and enhances the cost curve reliability. This has been applied to a case study by using data collected from the water supplier information system. The results obtained in this case study show significant outcomes in respect of both identification of an economically optimal target and prevention of unnecessary investment to meet this aim. This advance in leakage management allows water suppliers to select a rational target and manage their system economically and efficiently.This work has been funded and supported by K-water which is the public water company in South Kore