Acanthagrion marinae sp. Nov. (zygoptera: Coenagrionidae): A new species of the apicale group

Acanthagrion marinae sp. nov. (Holotype male: BRASIL, Mato Grosso do Sul, Campo Grande, UFMS, 20°29’56.26’’S-54°36’48.43’’W, 547m, leg. M.E. Rodrigues, 03.ii.2015, collection code: VZYG437, MLP) is described and illustrated on the basis of 15 males. The new species belongs to the apicale species group by having horns on S10 and sclerotized hooks on tip of distal segment of the genital ligula. It can be easily distinguished from other species of the group by a combination of characters of the genital ligulae (presence of setae on segment two; absence of setae at flexure; distal lateral lobes of segment three absent). Notes on habitat and a modification of previous keys for the species of the apicale group are provided.Fil: Lozano, Federico. Universidad Nacional de Avellaneda. Departamento de Ciencias Ambientales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodrigues, Marciel E. Universidade Estadual de Santa Cruz; Brasi

Regularity for the near field parallel refractor and reflector problems

We prove local $C^{1,\alpha}$ estimates of solutions for the parallel refractor and reflector problems under local assumptions on the target set $\Sigma$, and no assumptions are made on the smoothness of the densities.Comment: 32 pages, three figure

Language modeling and transcription of the TED corpus lectures

Transcribing lectures is a challenging task, both in acoustic and in language modeling. In this work, we present our first results on the automatic transcription of lectures from the TED corpus, recently released by ELRA and LDC. In particular, we concentrated our effort on language modeling. Baseline acoustic and language models were developed using respectively 8 hours of TED transcripts and various types of texts: conference proceedings, lecture transcripts, and conversational speech transcripts. Then, adaptation of the language model to single speakers was investigated by exploiting different kinds of information: automatic transcripts of the talk, the title of the talk, the abstract and, finally, the paper. In the last case, a 39.2% WER was achieved

Welfare-based optimal monetary policy with unemployment and sticky prices: a linear-quadratic framework

In this paper, we derive a linear-quadratic model for monetary policy analysis that is consistent with sticky prices and search and matching frictions in the labor market. We show that the second-order approximation to the welfare of the representative agent depends on inflation and "gaps" that involve current and lagged unemployment. Our approximation makes explicit how the costs of fluctuations are generated by the presence of search frictions. These costs are distinct from the costs associated with relative price dispersion and fluctuations in consumption that appear in standard new Keynesian models. We use the model to analyze optimal monetary policy under commitment and discretion and to show that the structural characteristics of the labor market have important implications for optimal policy.Monetary policy ; Econometric models

The welfare consequences of monetary policy

We explore the distortions in business cycle models arising from inefficiencies in price setting and in the search process matching firms to unemployed workers, and the implications of these distortions for monetary policy. To this end, we characterize the tax instruments that would implement the first best equilibrium allocations and then examine the trade-offs faced by monetary policy when these tax instruments are unavailable. Our findings are that the welfare cost of search inefficiency can be large, but the incentive for policy to deviate from the inefficient flexible-price allocation is in general small. Sizable welfare gains are available if the steady state of the economy is inefficient, and these gains do not depend on the existence of an inefficient dispersion of wages. Finally, the gains from deviating from price stability are larger in economies with more volatile labor flows, as in the U.S.Labor market

Gauss-Codazzi thermodynamics on the timelike screen

It is a known result by Jacobson that the flux of energy-matter through a local Rindler horizon is related with the expansion of the null generators in a way that mirrors the first law of thermodynamics. We extend such a result to a timelike screen of observers with finite acceleration. Since timelike curves have more freedom than null geodesics, the construction is more involved than Jacobson's and few geometrical constraints need to be imposed: the observers' acceleration has to be constant in time and everywhere orthogonal to the screen. Moreover, at any given time, the extrinsic curvature of the screen has to be flat. The latter requirement can be weakened by asking that the extrinsic curvature, if present at the beginning, evolves in time like on a cone and just rescales proportionally to the expansion.Comment: 8+1 pages, final versio

The Welfare Consequences of Monetary Policy and the Role of the Labor Market: a Tax Interpretation

We explore the distortions in business cycle models arising from inefficiencies in price setting and in the search process matching firms to unemployed workers, and the implications of these distortions for monetary policy. To this end, we characterize the tax instruments that would implement the first best equilibrium allocations and then examine the trade-offs faced by monetary policy when tax instruments are unavailable. Our findings are that the welfare cost of search inefficiency can be large, but the incentive for policy to deviate from the inefficient flexible-price allocation is in general small. Sizable welfare gains are available if the steady state of the economy is inefficient, and these gains do not depend on the existence of an inefficient dispersion of wages. Finally, the gains from deviating from price stability are larger in economies with more volatile labor flows, as in the U.S.Optimal monetary policy, search inefficiency, job vacancies, unemployment

The Welfare Consequences of Monetary Policy and the Role of the Labor Market: a Tax Interpretation

We explore the distortions in business cycle models arising from inefficiencies in price setting and in the search process matching firms to unemployed workers, and the implications of these distortions for monetary policy. To this end, we characterize the tax instruments that would implement the first best equilibrium allocations and then examine the trade-offs faced by monetary policy when these tax instruments are unavailable. Our findings are that the welfare cost of search inefficiency can be large, but the incentive for policy to deviate from the inefficient flexible-price allocation is in general small. Sizable welfare gains are available if the steady state of the economy is inefficient, and these gains do not depend on the existence of an inefficient dispersion of wages. Finally, the gains from deviating from price stability are larger in economies with more volatile labor flows, as in the U.S.