1,009 research outputs found

    Time Resolved Control of Electron Tunnelling Times and Single-shot Spin Readout in a Quantum Dot

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    We are pursuing a capability to perform time resolved manipulations of single spins in quantum dot circuits involving more than two quantum dots. In this paper, we demonstrate full counting statistics as well as averaging techniques we use to calibrate the tunnel barriers. We make use of this to implement the Delft protocol for single shot single spin readout in a device designed to form a triple quantum dot potential. We are able to tune the tunnelling times over around three orders of magnitude. We obtain a spin relaxation time of 300 microseconds at 10T.Comment: Submitted to EP2DS 2009 Conference Proceeding

    Improving outcomes for older people in the emergency department : a review of reviews

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    Background: There has been a recognised trend of increasing use of emergency and urgent care and emergency departments (EDs) by older people, which is marked by a substantial evidence base reporting interventions for this population and guidance from key organisations. Despite this, outcomes for this population remain suboptimal. A plethora of reviews in this area provides challenges for clinicians and commissioners in determining which interventions and models of care best meet people’s needs. The aim of this review was to identify effective ED interventions which have been reported for older people, and to provide a clear summary of the myriad reviews and numerous intervention types in this area. Methods: A review of reviews, reporting interventions for older people, either initiated or wholly delivered within the ED. Results: A total of 15 review articles describing 83 primary studies met our content and reporting standards criteria. The majority (n=13) were systematic reviews (four using meta-analysis.) Across the reviews, 26 different outcomes were reported with inconsistency. Follow-up duration varied within and across the reviews. Based on how authors had reported results, evidence clusters were developed: (1) staff-focused reviews, (2) discharge intervention reviews, (3) population-focused reviews and (4) intervention component reviews. Conclusions: The evidence base describing interventions is weak due to inconsistent reporting, differing emphasis placed on the key characteristics of primary studies (staff, location and outcome) by review authors and varying quality of reviews. No individual interventions have been found to be more promising, but interventions initiated in the ED and continued into other settings have tended to result in more favourable patient and health service outcomes. Despite many interventions reported within the reviews being holistic and patient focused, outcomes measured were largely service focused. PROSPERO registration number: PROSPERO CRD42018111461

    Оценивание устойчивого развития окружающей среды на субнациональном уровне в Украине

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    Рассмотрены существующие методы оценивания устойчивого развития окружающей среды (самостоятельные индикаторы, а также их системы и индексы). Предложен индекс устойчивого развития окружающей среды для оценивания взаимоотношений с окружающей средой на уровне регионов Украины, учитывающий национальные приоритеты в экологической политике. По предложенному региональному индексу получены экологические профили и рейтинг областей Украины.Розглянуто існуючі методи оцінювання сталого розвитку довкілля (самостійні індикатори, а також їх системи та індекси). Запропоновано індекс сталого розвитку довкілля для оцінювання взаємовідносин із навколишнім середовищем на рівні регіонів України, який враховує національні пріоритети в екологічній політиці. За запропонованим регіональним індексом отримано екологічні профілі і рейтинг областей України.The existing methods for assessment of the environment sustainable development (independent indicators, their systems and indices) are considered. The environment sustainability index for assessment of relations with the environment at a regional level for Ukraine is proposed, which takes into account the national priorities in ecological policy. Ecological profiles and rating of the Ukrainian regions are obtained according to the proposed regional index

    Development and calibration of a currency trading strategy using global optimization

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    We have developed a new financial indicator—called the Interest Rate Differentials Adjusted for Volatility (IRDAV) measure—to assist investors in currency markets. On a monthly basis, we rank currency pairs according to this measure and then select a basket of pairs with the highest IRDAV values. Under positive market conditions, an IRDAV based investment strategy (buying a currency with high interest rate and simultaneously selling a currency with low interest rate, after adjusting for volatility of the currency pairs in question) can generate significant returns. However, when the markets turn for the worse and crisis situations evolve, investors exit such money-making strategies suddenly, and—as a result—significant losses can occur. In an effort to minimize these potential losses, we also propose an aggregated Risk Metric that estimates the total risk by looking at various financial indicators across different markets. These risk indicators are used to get timely signals of evolving crises and to flip the strategy from long to short in a timely fashion, to prevent losses and make further gains even during crisis periods. Since our proprietary model is implemented in Excel as a highly nonlinear “black box” computational procedure, we use suitable global optimization methodology and software—the Lipschitz Global Optimizer solver suite linked to Excel—to maximize the performance of the currency basket, based on our selection of key decision variables. After the introduction of the new currency trading model and its implementation, we present numerical results based on actual market data. Our results clearly show the advantages of using global optimization based parameter settings, compared to the typically used “expert estimates” of the key model parameters.post-prin

    Revisiting the Local Scaling Hypothesis in Stably Stratified Atmospheric Boundary Layer Turbulence: an Integration of Field and Laboratory Measurements with Large-eddy Simulations

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    The `local scaling' hypothesis, first introduced by Nieuwstadt two decades ago, describes the turbulence structure of stable boundary layers in a very succinct way and is an integral part of numerous local closure-based numerical weather prediction models. However, the validity of this hypothesis under very stable conditions is a subject of on-going debate. In this work, we attempt to address this controversial issue by performing extensive analyses of turbulence data from several field campaigns, wind-tunnel experiments and large-eddy simulations. Wide range of stabilities, diverse field conditions and a comprehensive set of turbulence statistics make this study distinct

    Precision Measurement of PArity Violation in Polarized Cold Neutron Capture on the Proton: the NPDGamma Experiment

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    The NPDGamma experiment at the Los Alamos Neutron Science Center (LANSCE) is dedicated to measure with high precision the parity violating asymmetry in the γ\gamma emission after capture of spin polarized cold neutrons in para-hydrogen. The measurement will determine unambiguously the weak pion-nucleon-nucleon (πNN\pi NN) coupling constant {\it fπ1^1_{\pi}}Comment: Proceedings of the PANIC'05 Conference, Santa Fe, NM, USA, October 24-28, 2005, 3 pages, 2 figure

    Companions of Stars: From Other Stars to Brown Dwarfs to Planets: The Discovery of the First Methane Brown Dwarf

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    The discovery of the first methane brown dwarf provides a framework for describing the important advances in both fundamental physics and astrophysics that are due to the study of companions of stars. I present a few highlights of the history of this subject along with details of the discovery of the brown dwarf Gliese 229B. The nature of companions of stars is discussed with an attempt to avoid biases induced by anthropocentric nomenclature. With the newer types of remote reconnaissance of nearby stars and their systems of companions, an exciting and perhaps even more profound set of contributions to science is within reach in the near future. This includes an exploration of the diversity of planets in the universe and perhaps soon the first solid evidence for biological activity outside our Solar System.Comment: 31 pages, 13 figure

    Assessing neurosky's usability to detect attention levels in an assessment exercise

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    This paper presents the results of a usability evaluation of the NeuroSky's MindSet (MS). Until recently most Brain Computer Interfaces (BCI) have been designed for clinical and research purposes partly due to their size and complexity. However, a new generation of consumer-oriented BCI has appeared for the video game industry. The MS, a headset with a single electrode, is based on electro-encephalogram readings (EEG) capturing faint electrical signals generated by neural activity. The electrical signal across the electrode is measured to determine levels of attention (based on Alpha waveforms) and then translated into binary data. This paper presents the results of an evaluation to assess the usability of the MS by defining a model of attention to fuse attention signals with user-generated data in a Second Life assessment exercise. The results of this evaluation suggest that the MS provides accurate readings regarding attention, since there is a positive correlation between measured and self-reported attention levels. The results also suggest there are some usability and technical problems with its operation. Future research is presented consisting of the definition a standardized reading methodology and an algorithm to level out the natural fluctuation of users' attention levels if they are to be used as inputs
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