A General Equilibrium Financial Asset Economy with Transaction Costs and Trading Constraints

This paper presents a unified framework for examining the general equilibrium effects of transactions costs and trading constraints on security market trades and prices. The model uses a discrete time/state framework and Kuhn-Tucker theory to characterize the optimal decisions of consumers and financial intermediaries. Transaction costs and constraints give rise to regions of no trade and to bid-ask spreads: their existence frustrate the derivation of standard results in arbitrage-based pricing. Nevertheless, we are able to obtain as dual characterizations of our primal problems, one-sided arbitrage pricing results and a personalized martingale representation of asset pricing. These pricing results are identical to those derived by Jouini and Kallal (1995) using arbitrage arguments. The paper's framework incorporates a number of specialized existing models and results, proves new results and discusses new directions for research. In particular, we include characterizations of intermediaries who hold optimal portfolios; brokers who do not hold portfolios, and consumer-specific transactions costs and trading constraints. Furthermore we show that in the special case of equiproportional transaction costs and a sufficient number of assets, there is an analogue of the arbitrage pricing result for European derivatives where prices are interpreted as mid-prices between the bid-ask spread. We discuss the effects of non-convex transaction technologies on prices and trades.Financial Markets, Transaction Costs, Trading Constraints, Asset Pricing, General Equilibrium, Incomplete Markets

Feedforward and feedback control in apraxia of speech: effects of noise masking on vowel production

PURPOSE: This study was designed to test two hypotheses about apraxia of speech (AOS) derived from the Directions Into Velocities of Articulators (DIVA) model (Guenther et al., 2006): the feedforward system deficit hypothesis and the feedback system deficit hypothesis. METHOD: The authors used noise masking to minimize auditory feedback during speech. Six speakers with AOS and aphasia, 4 with aphasia without AOS, and 2 groups of speakers without impairment (younger and older adults) participated. Acoustic measures of vowel contrast, variability, and duration were analyzed. RESULTS: Younger, but not older, speakers without impairment showed significantly reduced vowel contrast with noise masking. Relative to older controls, the AOS group showed longer vowel durations overall (regardless of masking condition) and a greater reduction in vowel contrast under masking conditions. There were no significant differences in variability. Three of the 6 speakers with AOS demonstrated the group pattern. Speakers with aphasia without AOS did not differ from controls in contrast, duration, or variability. CONCLUSION: The greater reduction in vowel contrast with masking noise for the AOS group is consistent with the feedforward system deficit hypothesis but not with the feedback system deficit hypothesis; however, effects were small and not present in all individual speakers with AOS. Theoretical implications and alternative interpretations of these findings are discussed.R01 DC002852 - NIDCD NIH HHS; R01 DC007683 - NIDCD NIH HH

Economic aspects of the bee industry /

B55

Studies of the composition of milk

Cover title.Bibliography: p. 60

A general equilibrium financial asset economy with transaction costs and trading constraints

This paper presents a unified framework for examining the general equilibrium effects of transactions costs and trading constraints on security market trades and prices. The model uses a discrete time/state framework and Kuhn- Tucker theory to characterize the optimal decisions of consumers and financial intermediaries. Transaction costs and constraints give rise to regions of no trade and to bid-ask spreads: their existence frustrate the derivation of standard results in arbitrage-based pricing. Nevertheless, we are able to obtain as dual characterisations of our primal problems, one-sided arbitrage pricing results and a personalised martingale representation of asset pricing. These pricing results are identical to those derived by Jouini and Kallal (1995) using arbitrage arguments. The paper's framework incorporates a number of specialised existing models and results, proves new results and discusses new directions for research. In particular, we include characterisations of intermediaries who hold optimal portfolios; brokers who do not hold portfolios, and consumer-specific transactions costs and trading constraints. Furthermore we show that in the special case of equiproportional transaction costs and a sufficient number of assets, there is an analogue of the arbitrage pricing result for European derivatives where prices are interpreted as mid-prices between the bid-ask spread. We discuss the effects of non-convex transaction technologies on prices and trades

Kansen voor ’t Gorechthuis:’t Gorechthuis op eigen benen

De Gereformeerde Kerk in Haren beheert en exploiteert 't Gorechthuis, het is onderdeel van het complex mede bestaande uit de Gorechtkerk en jeugdgebouw 't Schip. Het College van Kerkrentmeesters is verantwoordelijk voor het beheer en de exploitatie van dit complex. Zij heeft geconstateerd dat de kosten van beheer en exploitatie stijgen en dat de inkomsten onvoldoende stijgen. De beheerders van ’t Gorechthuis willen graag weten op welke manier zij meer inkomsten kunnen genereren en of de manier waarop zij nu te werk gaan wel rendabel genoeg is. De vraagstelling die de Commissie Gorecht heeft is: Op welke manier kunnen er hogere inkomsten gegenereerd worden voor ´t Gorechthuis? Aansluitend op de vraagstelling die de Commissie Gorecht heeft geformuleerd is er voor het vooronderzoek de volgende vraagstelling geformuleerd: Wat is op dit moment de huidige situatie van ’t Gorechthuis? Het doel van het vooronderzoek is om de commissie Gorecht inzicht te geven in de tevredenheid van de gebruikers van ’t Gorechthuis. Hierdoor wordt duidelijk wat de plus en –minpunten zijn van ’t Gorechthuis. Op deze manier kan ’t Gorechthuis enkele veranderingen doorvoeren en hierdoor wordt de bezettingsgraad verhoogd. Studentonderzoek in het kader van het thema Leefomgevin

Feedback and Feedforward Control in Speech Production in Apraxia of Speech and Aphasia

Apraxia of speech (AOS) is considered to be a speech motor planning impairment (e.g., McNeil et al., 2009), but the nature of this impairment remains poorly understood. The present study was designed to test two hypotheses about the nature of AOS, framed in the DIVA model (Guenther et al., 2006). The DIVA model assumes that speech targets are regions in auditory space, and combines two control mechanisms to reach those targets: feedback control and feedforward control. The feedback mechanism generates corrective motor commands when the actual speech sound deviates from the intended speech sound. The feedforward mechanism generates predictive motor commands based on past experiences with the speech target. In the context of the DIVA model, we developed two hypotheses about possible underlying deficits in AOS. The Feedforward Control Impairment (FF) hypothesis states that feedforward control is impaired in AOS, with consequently a greater reliance on feedback control (Jacks, 2008). The Feedback Control Impairment (FB) hypothesis states that feedback control is impaired in AOS; concurrent feedback may be disruptive (cf. Ballard & Robin, 2007). We tested these hypotheses by measuring acoustic vowel contrast in two conditions: normal listening and auditory feedback masking. Under masking conditions, unimpaired speakers maintain segmental contrast (suggesting adequate feedforward commands to support speech without auditory feedback) even though contrast is somewhat reduced (suggesting on-line use of auditory feedback) (Perkell et al., 2007). The FF hypothesis predicts a greater reduction of segmental contrast with feedback masking in speakers with AOS than in controls, because effective removal of the auditory feedback control strategy will reveal the impaired feedforward commands. The FB hypothesis, in contrast, predicts increased segmental contrast with feedback masking, because removal of auditory feedback will allow the intact feedforward commands to produce adequate contrasts. One previous study that used feedback masking in AOS examined vowel duration and found longer vowels with masking in AOS and controls (Rogers et al., 1996); the present study also examined vowel duration

Two-resonator circuit QED: Dissipative Theory

We present a theoretical treatment for the dissipative two-resonator circuit quantum electrodynamics setup referred to as quantum switch. There, switchable coupling between two superconducting resonators is mediated by a superconducting qubit operating in the dispersive regime, where the qubit transition frequency is far detuned from those of the resonators. We derive an effective Hamiltonian for the quantum switch beyond the rotating wave approximation and study the dissipative dynamics within a Bloch-Redfield quantum master equation approach. We derive analytically how the qubit affects the quantum switch even if the qubit has no dynamics, and we estimate the strength of this influence. The analytical results are corroborated by numerical calculations, where coherent oscillations between the resonators, the decay of coherent and Fock states, and the decay of resonator-resonator entanglement are studied. Finally, we suggest an experimental protocol for extracting the damping constants of qubit and resonators by measuring the quadratures of the resonator fields.Comment: 17 pages, 9 figure