Minimal Riesz Energy Point Configurations for Rectifiable d-Dimensional Manifolds

For a compact set A in Euclidean space we consider the asymptotic behavior of optimal (and near optimal) N-point configurations that minimize the Riesz s-energy (corresponding to the potential 1/t^s) over all N-point subsets of A, where s>0. For a large class of manifolds A having finite, positive d-dimensional Hausdorff measure, we show that such minimizing configurations have asymptotic limit distribution (as N tends to infinity with s fixed) equal to d-dimensional Hausdorff measure whenever s>d or s=d. In the latter case we obtain an explicit formula for the dominant term in the minimum energy. Our results are new even for the case of the d-dimensional sphere.Comment: paper: 29 pages and addendum: 4 page

Bidirectional syntactic priming across cognitive domains: from arithmetic to language and back

Scheepers et al. (2011) showed that the structure of a correctly solved mathematical equation affects how people subsequently complete sentences containing high vs. low relative-clause attachment ambiguities. Here we investigated whether such effects generalise to different structures and tasks, and importantly, whether they also hold in the reverse direction (i.e., from linguistic to mathematical processing). In a questionnaire-based experiment, participants had to solve structurally left- or right-branching equations (e.g., 5 × 2 + 7 versus 5 + 2 × 7) and to provide sensicality ratings for structurally left- or right-branching adjective-noun-noun compounds (e.g., alien monster movie versus lengthy monster movie). In the first version of the experiment, the equations were used as primes and the linguistic expressions as targets (investigating structural priming from maths to language). In the second version, the order was reversed (language-to-maths priming). Both versions of the experiment showed clear structural priming effects, conceptually replicating and extending the findings from Scheepers et al. (2011). Most crucially, the observed bi-directionality of cross-domain structural priming strongly supports the notion of shared syntactic representations (or recursive procedures to generate and parse them) between arithmetic and language

IMPLICATION OF IMPROVED IRRIGATION PUMPING EFFICIENCY FOR FARMER PROFIT AND ENERGY USE

Resource /Energy Economics and Policy,

TEMPORAL IMPLICATIONS OF LIMITATIONS ON ANNUAL IRRIGATION WATER PUMPED FROM AN EXHAUSTIBLE AQUIFER

Economic losses caused by uncontrolled pumping of groundwater is of major concern on the Texas High Plains. A recursive linear programming model is used to evaluate various annual limitations on aquifer depletion. Results indicate that, especially under furrow irrigation, some limitations on groundwater withdrawal could be beneficial to society as well as the producers.Resource /Energy Economics and Policy,

Credit Line Availability and Utilization in REITs

Analysis of REIT credit line availability and use under normal conditions and during the recent financial crisis are provided. Descriptive statistics indicate REIT credit lines represent an important component of capital structure, credit line availability and utilization have increased substantially over the sample period, and REITs maintain precautionary liquidity via credit lines rather than holding cash. Multivariate results indicate that credit line availability is directly associated with cash flow uncertainty, dividend distributions, acquisitions, and capital market access and is inversely linked to the market-to-book ratio. Credit line use is unrelated to cash flow volatility and dividends, but is correlated with operating cash flow, acquisitions, and capital market access. Unlike with non-REITs, when setting credit limits lenders focus on dividends and not just operating cash flow. Despite finding that line availability is influenced by dividend payments, REITs do not systematically use lines to pay dividends implying that dividends are paid from operating cash flows.