6,661 research outputs found

    Commentary

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    Ronald J. Tabak, Chair of the Committee on the Death Penalty for the American Bar Association\u27s Section of Individual Rights and Responsibilities, discusses the Section\u27s purpose in organizing Forhdam University School of Law\u27s panel discussion on Politics and the Death Penalty. The goal was to illuminate the variety of effects of a widespread perception that the belief of legislators, governors, prosecutors, judges, clemency boards, political candidates and others that the public is overwhelmingly in support of capital punishment. The Section aimed to bring together knowledgeable people from a variety of perspectives to discuss (a) how the capital punishment system and the political process have been affected by the perceived overwhelming popular support for the death penalty, (b) the role that reportage - or the lack thereof - has had on public attitudes about the death penalty and (c) whether opponents of capital punishment can survive politically. Taback then gives an overview of what was discussed by each panelist, which included Norman Redlich, former Dean of New York University Law School, James Coleman, Shabata Sundiata Waglini, Attorney General Ernest Preate, Jr., Bryan Stevenson, Executive Director of the Alabama Capital Representation Resource Center, journalist Nat Hentoff, New York State Assemblywoman Susan John, and Chief Justice Exum of the North Carolina Supreme Court discuss the issue of the death penalty in America

    Trapped Modes in Linear Quantum Stochastic Networks with Delays

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    Networks of open quantum systems with feedback have become an active area of research for applications such as quantum control, quantum communication and coherent information processing. A canonical formalism for the interconnection of open quantum systems using quantum stochastic differential equations (QSDEs) has been developed by Gough, James and co-workers and has been used to develop practical modeling approaches for complex quantum optical, microwave and optomechanical circuits/networks. In this paper we fill a significant gap in existing methodology by showing how trapped modes resulting from feedback via coupled channels with finite propagation delays can be identified systematically in a given passive linear network. Our method is based on the Blaschke-Potapov multiplicative factorization theorem for inner matrix-valued functions, which has been applied in the past to analog electronic networks. Our results provide a basis for extending the Quantum Hardware Description Language (QHDL) framework for automated quantum network model construction (Tezak \textit{et al.} in Philos. Trans. R. Soc. A, Math. Phys. Eng. Sci. 370(1979):5270-5290, to efficiently treat scenarios in which each interconnection of components has an associated signal propagation time delay

    The Dynamic Relationship between Stock Prices and Exchange Rates: evidence for Brazil

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    This paper studies the dynamic relationship between stock prices and exchange rates in the Brazilian economy. We use recently developed unit root and cointegration tests, which allow endogenous breaks, to test for a long run relationship between these variables. We performed linear, and nonlinear causality tests after considering both volatility and linear dependence. We found that there is no long-run relationship, but there is linear Granger causality from stock prices to exchange rates, in line with the portfolio approach: stock prices lead exchange rates with a negative correlation. Furthermore, we found evidence of nonlinear Granger causality from exchange rates to stock prices, in line with the traditional approach: exchange rates lead stock prices. We believe these findings have practical applications for international investors

    Monetary Policy Surprises and the Brazilian Term Structure of Interest Rates

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    This paper examines the information content of COPOM decisions to change or to leave unchanged monetary policy by estimating the responses of the term structure to changes in the target for interest rates on COPOM meeting days. Within an event-study approach the evidence suggests that market participants anticipate, at least partially, monetary policy actions. Furthermore, it is found that the introduction of the floating exchange and inflation-targeting regime has had a dampening effect on interest rate surprises along the term structure.

    On the Information Content of Oil Future Prices

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    This paper deals with the efficiency of the Brent Crude oil future contracts and tests whether futures can be used to predict realized oil spot prices. Evidence suggests that future prices up to three-months contracts on Brent Crude are unbiased predictors of future spot prices but the explanation power is not high (around 20%). Furthermore, using cointegration techniques the unbiasedness hypothesis for future prices as predictors of realized spot prices could not be rejected. When the sample is divided into sub-periods, the absence of bias in futures prices is rejected.

    The Random Walk Hypothesis and the Behavior of Foreign Capital Portfolio Flows: the Brazilian Stock Market Case

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    In this paper the random walk hypothesis is tested for a set of daily Brazilian stock data given by the São Paulo Stock Exchange Index (IBOVESPA) in the period of 1986-1998. A rolling variance ratio test for different investment horizons was conducted, and it is concluded that prior to 1994 the random walk hypothesis is rejected but after that it cannot be rejected. Institutionally maturing markets, increasing liquidity and the openness of Brazilian markets for international capital can explain this increase of efficiency of the Brazilian stock market. An error-correction model is used to explain the relationship between the IBOVESPA and foreign portfolio inflows. Evidence suggests that the release of foreign capital control is one of the main determinants of increased efficiency in the Brazilian equity market.

    Systematic Stochastic Reduction of Inertial Fluid-Structure Interactions subject to Thermal Fluctuations

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    We present analysis for the reduction of an inertial description of fluid-structure interactions subject to thermal fluctuations. We show how the viscous coupling between the immersed structures and the fluid can be simplified in the regime where this coupling becomes increasingly strong. Many descriptions in fluid mechanics and in the formulation of computational methods account for fluid-structure interactions through viscous drag terms to transfer momentum from the fluid to immersed structures. In the inertial regime, this coupling often introduces a prohibitively small time-scale into the temporal dynamics of the fluid-structure system. This is further exacerbated in the presence of thermal fluctuations. We discuss here a systematic reduction technique for the full inertial equations to obtain a simplified description where this coupling term is eliminated. This approach also accounts for the effective stochastic equations for the fluid-structure dynamics. The analysis is based on use of the Infinitesmal Generator of the SPDEs and a singular perturbation analysis of the Backward Kolomogorov PDEs. We also discuss the physical motivations and interpretation of the obtained reduced description of the fluid-structure system. Working paper currently under revision. Please report any comments or issues to [email protected]: 19 pages, 1 figure. arXiv admin note: substantial text overlap with arXiv:1009.564
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