Impervious Surface Analysis for Durham Under Current and Build-Out Conditions In Support of Stormwater Management

An analysis was performed to determine current and projected impervious surface areas in the Town of Durham, New Hampshire with the purpose of generating data to guide the adoption of stormwater management practices in the Town. Because impervious surfaces affect stormwater runoff peak flows and volumes significantly, it is critical to understand the Town’s impervious area characteristics (and the resulting stormwater management implications) under current conditions in order to develop appropriate stormwater management policies

Consequences of Weyl Consistency Conditions

The running of quantum field theories can be studied in detail with the use of a local renormalization group equation. The usual beta-function effects are easy to include, but by introducing spacetime-dependence of the various parameters of the theory one can efficiently incorporate renormalization effects of composite operators as well. An illustration of the power of these methods was presented by Osborn in the early 90s, who used consistency conditions following from the Abelian nature of the Weyl group to rederive Zamolodchikov's c-theorem in d=2 spacetime dimensions, and also to obtain a perturbative a-theorem in d=4. In this work we present an extension of Osborn's work to d=6 and to general even d. We compute the full set of Weyl consistency conditions, and we discover among them a candidate for an a-theorem in d=6, similar to the d=2,4 cases studied by Osborn. Additionally, we show that in any even spacetime dimension one finds a consistency condition that may serve as a generalization of the c-theorem, and that the associated candidate c-function involves the coefficient of the Euler term in the trace anomaly. Such a generalization hinges on proving the positivity of a certain "metric" in the space of couplings.Comment: 19 pages, Mathematica file with consistency conditions included in submission. v2: Fixed typo

How Should Monetary Policy Respond to Asset-Price Bubbles?

We present a simple macroeconomic model that includes a role for an asset-price bubble. We then derive optimal monetary policy settings for two policymakers: a skeptic, for whom the best forecast of future asset prices is the current price; and an activist, whose policy recommendations take into account the complete stochastic implications of the bubble. We show that the activist’s recommendations depend sensitively on the detailed stochastic properties of the bubble. In some circumstances the activist clearly recommends tighter policy than the skeptic, but in others the appropriate recommendation is to be looser. Our results highlight the stringent informational requirements inherent in an activist policy approach to handling asset-price bubbles.

The NASA Electric Propulsion Program

The NASA OAST Propulsion, Power, and Energy Division supports an electric propulsion program aimed at providing benefits to a broad class of missions. Concepts which have the potential to enable or significantly benefit space exploration and exploitation are identified and advanced toward application in the near and far term. This paper summarizes recent program progress in mission/system analysis; in electrothermal, electrostatic, and electromagnetic propulsion technologies; and in propulsion/spacecraft integration

A challenge to the aa-theorem in six dimensions

The possibility of a strong $a$-theorem in six dimensions is examined in multi-flavor $\phi^3$ theory. Contrary to the case in two and four dimensions, we find that in perturbation theory the relevant quantity $\tilde{a}$ increases monotonically along flows away from the trivial fixed point. $\tilde{a}$ is a natural extension of the coefficient $a$ of the Euler term in the trace anomaly, and it arises in any even spacetime dimension from an analysis based on Weyl consistency conditions. We also obtain the anomalous dimensions and beta functions of multi-flavor $\phi^3$ theory to two loops. Our results suggest that some new intuition about the $a$-theorem is in order.Comment: 4 pages. v2: Fixed typos, added reference

Library Impact Data Project: hit, miss or maybe

Purpose In February 2011 the University of Huddersfield along with 7 partners were awarded JISC funding through the Activity Data programme to investigate the hypothesis that: “There is a statistically significant correlation across a number of universities between library activity data and student attainment” The Library Impact Data Project aimed to analyse users’ actions with regards to library usage and then linking those to final degree award. By identifying a positive correlation in this data those subject areas or courses which exhibit high usage of library resources can be used as models of good practice. Design, methodology or approach The overall approach of the project is to extract anonymised activity data from partners’ systems and analyse the findings. For each student who graduated in the sample years, the following data was required: final grade achieved; number of books borrowed; number of times e-resources were accessed; number of times each student entered the library and school or faculty. This data was then collated, normalised, and then analysed. In addition all partners were asked to hold a number of focus groups in order to secure qualitative data from students on library usage to provide a holistic picture of how students engage with library resources. Findings This paper will report on the findings of the project which ran from February to July 2011. It will consider whether the hypothesis was proven for the three indicators of library usage. Research or practical limitations or implications The main aim of the project was to support the hypothesis. The project acknowledges however, that the relationship between the two variables is not a causal relationship and there will be other factors which influence student attainment. Conclusions The paper will discuss the implications of the results and suggest further work that could result from the projects findings

Fairness and desert in tournaments

We model the behavior of agents who care about receiving what they feel they deserve in a two-player rank-order tournament. Perceived entitlements are sensitive to how hard an agent has worked relative to her rival, and agents are loss averse around their meritocratically determined endogenous reference points. In a fair tournament sufficiently large desert concerns drive identical agents to push their effort levels apart in order to end up closer to their reference points on average. In an unfair tournament, where one agent is advantaged, the equilibrium is symmetric in the absence of desert, but asymmetric in the presence of desert. We find that desert concerns can undermine the standard conclusion that competition for a fixed supply of status is socially wasteful and explain why, when the distribution of output noise is fat-tailed, an employer might use a rank-order incentive scheme. Keywords; desert, equity, tournament, loss aversion, reference-dependent preferences, reference point, psychological game theory, status, relative performance evaluation

Exploring the use of Controlled English for communication with ACT-R agents

Research is being undertaken into sense-making by collaborative agents, based upon a cognitive framework of human behaviour, ACT-R, together with communication between the agents. We explore the use of Controlled English for this purpos

Wetting morphologies on an array of fibers of different radii

We investigate the equilibrium morphology of a finite volume of liquid placed on two parallel rigid fibers of different radii. As observed for identical radii fibers, the liquid is either in a column morphology or adopts a drop shape depending on the inter-fiber distance. However the cross-sectional area and the critical inter-fiber distance at which the transition occurs are both modified by the polydispersity of the fibers. Using energy considerations, we analytically predict the critical inter-fiber distance corresponding to the transition between the column and the drop morphologies occurs. This distance depends both on the radii of the fibers and on the contact angle of the liquid. We perform experiments using a perfectly wetting liquid on two parallel nylon fibers: the results are in good agreement with our analytical model. The morphology of the capillary bridges between fibers of different radii is relevant to the modeling of large arrays of polydisperse fibers