523 research outputs found

    Briefing: sustainable drainage for sports pitch developments

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    Effective management of storm water is of paramount importance in urban development, and drainage design is usually governed by planning constraints. In the development of sports pitches, planning bodies often impose discharge constraints, and frequently class such areas as impermeable surfaces, thus treating their drainage behaviour in a similar fashion to roads and pavements, which may require the provision of separate attenuation. This briefing presents preliminary findings of a project to assess the drainage behaviour of sports pitch developments. The work undertaken to date suggests only a fraction of water falling on a pitch (rain) is discharged to the drains, identifying an apparent attenuation capacity and potential over-design within current sports pitch drainage systems. In addition to the low discharge volumes measured from pitch systems, there has also been a broad range of flow rates experienced. This led to the development of a bespoke flow monitoring device, FloPod. Designed and fabricated at Loughborough University, this device allows a broad range of flow rates to be measured without compromising aspects of data resolution and reliability – key factors that were not found in commercially available devices

    Drainage behaviour of sport pitches - findings from a research study

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    The drainage design of sports pitches has traditionally been based on experience and can be considered an inexact science. Whilst the sport surface can be adequately drained to meet specific criteria, estimating outflows at the discharge point is more challenging. The hydraulic performance of sports pitches has not previously been measured in detail prior to this study. Within the wider industry and regulatory bodies there is a perceived contribution to local flood risk of the storm water and run off from sport pitches. It is also apparent that artificial pitches have in some cases been treated in planning consents as impermeable. Observations from industry have suggested that in reality the pitch drainage systems discharge low volumes of water and low peak flow rates, with limited surface runoff (especially from porous artificial pitches). However, in some cases, for artificial pitches in particular, at planning stage the drainage design has required to include off-line tanks to provide storm water storage and attenuation. A lack of technical guidance on sport pitch design and drainage benefits may be leading to overdesign, and prompted this study. This 3 year study comprised field measurements of weather and discharge behaviour at a range of artificial and natural turf pitches in England; laboratory physical model testing of pitch component hydraulic behaviour; and mathematical modelling to predict how a pitch system may be expected to perform hydraulically. Bespoke field monitoring apparatus was developed as part of the research to measure across a large range of flow rates and volumes. The experimental work in this study has provided the evidence to demonstrate that the porous pitch designs provide high attenuation of peak rainfall events and large capacity for water storage, similar to the requirements of SuDs based ‘source control’ designs required in new urban developments. The field monitoring observations suggest that in reality the drainage system behaviour is not as consistent or predictable as might be expected from assumptions made in design software and that in all cases the measured outflow water volume was far less than that estimated from rainfall as the total water volume flowing into the pitch drainage system. The experimental work, combined with the mathematical modelling, has highlighted the key mechanisms that provide resistance to flow and explain the attenuation behaviour observed. It is considered that in most cases insufficient head is created in the sub-surface layers to drive water to the lateral drainage pipes, and that the high frictional resistance to flow in the corrugated collector pipes provide large ‘head’ losses under the low hydraulic gradients. The research findings support the claims by many in the industry that in some cases planning approvals, where a lack of understanding or evidence on how pitches can attenuate and store water exists, may be causing the over-design of pitch drainage systems requiring unnecessary offline storage tanks

    A reduced complexity numerical method for optimal gate synthesis

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    Although quantum computers have the potential to efficiently solve certain problems considered difficult by known classical approaches, the design of a quantum circuit remains computationally difficult. It is known that the optimal gate design problem is equivalent to the solution of an associated optimal control problem, the solution to which is also computationally intensive. Hence, in this article, we introduce the application of a class of numerical methods (termed the max-plus curse of dimensionality free techniques) that determine the optimal control thereby synthesizing the desired unitary gate. The application of this technique to quantum systems has a growth in complexity that depends on the cardinality of the control set approximation rather than the much larger growth with respect to spatial dimensions in approaches based on gridding of the space, used in previous literature. This technique is demonstrated by obtaining an approximate solution for the gate synthesis on SU(4)SU(4)- a problem that is computationally intractable by grid based approaches.Comment: 8 pages, 4 figure

    Drainage behavior of sports pitches–A case study review

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    The drainage behavior of sports pitches has traditionally been designed from experience with hydraulic performance rarely measured in detail. Within the wider industry and regulatory bodies there is a perception that storm water and increased drainage rates from sports pitches contribute to local flood risk. Empirical observations have suggested that in reality pitch drainage systems may discharge water at low volumes and rates and there is often limited surface run-off. Furthermore it appears that lack of technical guidance on the discharge of water from sport pitch drainage systems may have led to misunderstanding their drainage behavior and possible benefits they could bring to water management as opposed to perceived dis-benefits. This paper summarizes selected results of a case study which included field measurements of weather and discharge behavior on a range of natural turf sports pitches in England. The findings from this study indicate that natural turf sports pitches can provide resistance to flow and hence advantageous attenuation of rainfall and storm water. Additionally sports pitches can store large volumes of water within the pervious materials used in their design. The study has confirmed that sport pitches demonstrate the key functions that are reflected in the design requirements of Sustainable Urban Drainage Systems (SuDs) such as pervious pavements providing source control of surface rain water

    Understanding natural language commands for robotic navigation and mobile manipulation

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    This paper describes a new model for understanding natural language commands given to autonomous systems that perform navigation and mobile manipulation in semi-structured environments. Previous approaches have used models with fixed structure to infer the likelihood of a sequence of actions given the environment and the command. In contrast, our framework, called Generalized Grounding Graphs, dynamically instantiates a probabilistic graphical model for a particular natural language command according to the command's hierarchical and compositional semantic structure. Our system performs inference in the model to successfully find and execute plans corresponding to natural language commands such as "Put the tire pallet on the truck." The model is trained using a corpus of commands collected using crowdsourcing. We pair each command with robot actions and use the corpus to learn the parameters of the model. We evaluate the robot's performance by inferring plans from natural language commands, executing each plan in a realistic robot simulator, and asking users to evaluate the system's performance. We demonstrate that our system can successfully follow many natural language commands from the corpus

    Numerical Solution of the Dynamic Programming Equation for the Optimal Control of Quantum Spin Systems

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    The purpose of this paper is to describe the numerical solution of the Hamilton-Jacobi-Bellman (HJB) for an optimal control problem for quantum spin systems. This HJB equation is a first order nonlinear partial differential equation defined on a Lie group. We employ recent extensions of the theory of viscosity solutions from Euclidean space to Riemannian manifolds to interpret possibly non-differentiable solutions to this equation. Results from differential topology on the triangulation of manifolds are then used to develop a finite difference approximation method, which is shown to converge using viscosity solution techniques. An example is provided to illustrate the method.Comment: 11 pages, 5 figure

    Approaching the Symbol Grounding Problem with Probabilistic Graphical Models

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    In order for robots to engage in dialog with human teammates, they must have the ability to map between words in the language and aspects of the external world. A solution to this symbol grounding problem (Harnad, 1990) would enable a robot to interpret commands such as “Drive over to receiving and pick up the tire pallet.” In this article we describe several of our results that use probabilistic inference to address the symbol grounding problem. Our specific approach is to develop models that factor according to the linguistic structure of a command. We first describe an early result, a generative model that factors according to the sequential structure of language, and then discuss our new framework, generalized grounding graphs (G3). The G3 framework dynamically instantiates a probabilistic graphical model for a natural language input, enabling a mapping between words in language and concrete objects, places, paths and events in the external world. We report on corpus-based experiments where the robot is able to learn and use word meanings in three real-world tasks: indoor navigation, spatial language video retrieval, and mobile manipulation.U.S. Army Research Laboratory. Collaborative Technology Alliance Program (Cooperative Agreement W911NF-10-2-0016)United States. Office of Naval Research (MURI N00014-07-1-0749

    Dermatologist and Patient Preferences in Choosing Treatments for Moderate to Severe Psoriasis

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    INTRODUCTION: The objective of the study was to determine the relative importance (RI) of treatment attributes psoriasis patients and physicians consider when choosing between biologic therapies based on psoriasis severity. METHODS: A discrete choice experiment (DCE) weighting preference for eight sets of hypothetical treatments for moderate or severe psoriasis was conducted. DCE hypothetical treatments were defined and varied on combinations of efficacy, safety, and dosing attributes [frequency/setting/route of administration (ROA)]. RESULTS: When assuming moderate psoriasis in the patient DCE, ROA (RI 29%) and efficacy (RI 27%) drive treatment choices. When assuming severe disease in the DCE, patients preferred treatments with higher efficacy (RI 36%); ROA was relatively less important (RI 15%). From the physician perspective, ROA (RI 32%) and efficacy (RI 26%) were most important for moderate psoriasis patients. In the physician model for severe psoriasis, efficacy (RI 42%) was the predominant driver followed by ROA (RI 22%). Regardless of severity, probability of loss of response within 1 year was the least important factor. CONCLUSIONS: The severity of disease is a critical element in psoriasis treatment selection. There are high levels of alignment between physician- and patient-derived preferences in biologic treatment choice selection for psoriasis. FUNDING: Janssen Pharmaceuticals

    Development of the morpholino gene knockdown technique in Fundulus heteroclitus : a tool for studying molecular mechanisms in an established environmental model

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    Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Aquatic Toxicology 87 (2008): 289-295, doi:10.1016/j.aquatox.2008.02.010.A significant challenge in environmental toxicology is that many genetic and genomic tools available in laboratory models are not developed for commonly used environmental models. The Atlantic killifish (Fundulus heteroclitus) is one of the most studied teleost environmental models, yet few genetic or genomic tools have been developed for use in this species. The advancement of genetic and evolutionary toxicology will require that many of the tools developed in laboratory models be transferred into species more applicable to environmental toxicology. Antisense morpholino oligonucleotide (MO) gene knockdown technology has been widely utilized to study development in zebrafish and has been proven to be a powerful tool in toxicological investigations through direct manipulation of molecular pathways. To expand the utility of killifish as an environmental model, MO gene knockdown technology was adapted for use in Fundulus. Morpholino microinjection methods were altered to overcome the significant differences between these two species. Morpholino efficacy and functional duration were evaluated with molecular and phenotypic methods. A cytochrome P450-1A (CYP1A) MO was used to confirm effectiveness of the methodology. For CYP1A MO-injected embryos, a 70% reduction in CYP1A activity, a 86% reduction in total CYP1A protein, a significant increase in β-naphthoflavone-induced teratogenicity, and estimates of functional duration (50% reduction in activity 10 dpf, and 86% reduction in total protein 12 dpf) conclusively demonstrated that MO technologies can be used effectively in killifish and will likely be just as informative as they have been in zebrafish.This work was funded in part by the National Institute of Environmental Health Sciences through the Duke Superfund Basic Research Center (P42ES010356), the Boston University Superfund Basic Research Program (P42ES007381), and the Duke Integrated Toxicology and Environmental Health Program (ES-T32-0007031). Additional support was provided by a U.S. Environmental Protection Agency STAR fellowship awarded to C.R.F

    The PuZZling Li-Rich Red Giant Associated With NGC 6819

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    A Li-rich red giant (RG) star (2M19411367+4003382) recently discovered in the direction of NGC 6819 belongs to the rare subset of Li-rich stars that have not yet evolved to the luminosity bump, an evolutionary stage where models predict Li can be replenished. The currently favored model to explain Li enhancement in first-ascent RGs like 2M19411367+4003382 requires deep mixing into the stellar interior. Testing this model requires a measurement of C-12/C-13, which is possible to obtain from Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra. However, the Li-rich star also has abnormal asteroseismic properties that call into question its membership in the cluster, even though its radial velocity and location on color-magnitude diagrams are consistent with membership. To address these puzzles, we have measured a wide array of abundances in the Li-rich star and three comparison stars using spectra taken as part of the APOGEE survey to determine the degree of stellar mixing, address the question of membership, and measure the surface gravity. We confirm that the Li-rich star is a RG with the same overall chemistry as the other cluster giants. However, its log g is significantly lower, consistent with the asteroseismology results and suggestive of a very low mass if the star is indeed a cluster member. Regardless of the cluster membership, the C-12/C-13 and C/N ratios of the Li-rich star are consistent with standard first dredge-up, indicating that Li dilution has already occurred, and inconsistent with internal Li enrichment scenarios that require deep mixing.National Science Foundation AST1109888NSF AST-1358862, AST 1109718, AST 1312863Alfred P. Sloan FoundationNational Science FoundationU.S. Department of Energy Office of ScienceUniversity of ArizonaBrazilian Participation GroupBrookhaven National LaboratoryCarnegie Mellon UniversityUniversity of FloridaFrench Participation GroupGerman Participation GroupHarvard UniversityInstituto de Astrofisica de CanariasMichigan State/NotreDame/JINA Participation GroupJohns Hopkins UniversityLawrence Berkeley National LaboratoryMax Planck Institute for AstrophysicsMax Planck Institute for Extraterrestrial PhysicsNew Mexico State UniversityNew York UniversityOhio State UniversityPennsylvania State UniversityUniversity of PortsmouthPrinceton UniversitySpanish Participation GroupUniversity of TokyoUniversity of UtahVanderbilt UniversityUniversity of VirginiaUniversity of WashingtonYale UniversityNational Aeronautics and Space AdministrationTwo Micron All Sky SurveyUniversity of MassachusettsInfrared Processing and Analysis Center/California Institute of TechnologyU.S. Government NAG W-2166Astronom
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