Public Firms in a Dynamic Third Market Model

We set the third market model in a dynamic context to decide whether a country can achieve benefits by subsidizing a public rm's exports. We use calculus of variations with the constraint that the welfare is either maximized or grows at constant rate, reflecting the public concern of the firm. We conclude that a subsidy can be a good strategy for the country in some instances, even though only over a finite period of time. The duration of this period depends on the output strategy of the public firm as well as on exogenous factors.public firms, strategic trade policy, third market model, calculus of variations

Testing excitation models of rapidly oscillating Ap stars with interferometry

Rapidly oscillating Ap stars are unique objects in the potential they offer to study the interplay between a number of important physical phenomena, in particular, pulsations, magnetic fields, diffusion, and convection. Nevertheless, the simple understanding of how the observed pulsations are excited in these stars is still in progress. In this work we perform a test to what is possibly the most widely accepted excitation theory for this class of stellar pulsators. The test is based on the study of a subset of members of this class for which stringent data on the fundamental parameters are available thanks to interferometry. For three out of the four stars considered in this study, we find that linear, non-adiabatic models with envelope convection suppressed around the magnetic poles can reproduce well the frequency region where oscillations are observed. For the fourth star in our sample no agreement is found, indicating that a new excitation mechanism must be considered. For the three stars whose observed frequencies can be explained by the excitation models under discussion, we derive the minimum angular extent of the region where convection must be suppressed. Finally, we find that the frequency regions where modes are expected to be excited in these models is very sensitive to the stellar radius. This opens the interesting possibility of determining this quantity and related ones, such as the effective temperature or luminosity, from comparison between model predictions and observations, in other targets for which these parameters are not well determined.Comment: Accepted for publication in the MNRA

EMBRAPA lança novas variedades de mandioca tolerantes ao mal da podridão mole.

bitstream/item/42278/1/Id39826.pdfFonte: Izabel Drulla Brandão, CPATU

Leadership preferences behaviors and its influence on athletes’ performance

The main objective of this study was to evaluate volleyball athletes´ perception of the coach behavior and its relationship with the performance in games. For those, 12 male, Brazilian volleyball high-level players, with mean of age 20.6 years were evaluated through an open question: “Do you see a relationship between the leadership style of your coach and your performance in games? The answers were analyzed through the Discourse of the Collective Subject. Data showed that 75% of the players tended to perceived the coach behavior as influencing directly their performance (“The coach leadership is essential for my performance”); 17% perceive it in a subordinate way (“Sometimes yes, sometimes, no, depends...”), and 8% perceived as no influence (“Leadership and performance are different”). In conclusion, we can say that there is a tendency to perceive the coach behavior as directly connected with the performance

Controlling the stability of both the structure and velocity of domain walls in magnetic nanowires

For magnetic nanowire devices, the precise control of both domain wall (DW) motion and pinning behaviour is essential for reliable functional performance. The domain wall velocity and wall structure are typically sensitive to the driving field or spin-polarized current, and the pinning behaviour depends on the walls’ structure and chirality, leading to variability in behaviour. Here, a systematic study combining experimental measurements and micromagnetic simulations of planar nanowires with small fixed-angle structural modulations on both edges was undertaken to study the domain wall reversal regime. A phase diagram for the reversal field as a function of modulation amplitude was obtained that shows that three DW reversal regime. A range of field and modulation amplitudes were identified in which stable DW reversal occurs, where the wall velocity is constant as a function of field and the wall structure is stable, which is well suited to applications

Entangled inputs cannot make imperfect quantum channels perfect

Entangled inputs can enhance the capacity of quantum channels, this being one of the consequences of the celebrated result showing the non-additivity of several quantities relevant for quantum information science. In this work, we answer the converse question (whether entangled inputs can ever render noisy quantum channels have maximum capacity) to the negative: No sophisticated entangled input of any quantum channel can ever enhance the capacity to the maximum possible value; a result that holds true for all channels both for the classical as well as the quantum capacity. This result can hence be seen as a bound as to how "non-additive quantum information can be". As a main result, we find first practical and remarkably simple computable single-shot bounds to capacities, related to entanglement measures. As examples, we discuss the qubit amplitude damping and identify the first meaningful bound for its classical capacity.Comment: 5 pages, 2 figures, an error in the argument on the quantum capacity corrected, version to be published in the Physical Review Letter

The quantum one-time pad in the presence of an eavesdropper

A classical one-time pad allows two parties to send private messages over a public classical channel -- an eavesdropper who intercepts the communication learns nothing about the message. A quantum one-time pad is a shared quantum state which allows two parties to send private messages or private quantum states over a public quantum channel. If the eavesdropper intercepts the quantum communication she learns nothing about the message. In the classical case, a one-time pad can be created using shared and partially private correlations. Here we consider the quantum case in the presence of an eavesdropper, and find the single letter formula for the rate at which the two parties can send messages using a quantum one-time pad

Solos do campo experimental da Embrapa Milho e Sorgo: suas características e classificação no novo Sistema Brasileiro.

bitstream/CNPS/11831/1/bpd05_2002_milho_sorgo.pd

Are all maximally entangled states pure?

We study if all maximally entangled states are pure through several entanglement monotones. In the bipartite case, we find that the same conditions which lead to the uniqueness of the entropy of entanglement as a measure of entanglement, exclude the existence of maximally mixed entangled states. In the multipartite scenario, our conclusions allow us to generalize the idea of monogamy of entanglement: we establish the \textit{polygamy of entanglement}, expressing that if a general state is maximally entangled with respect to some kind of multipartite entanglement, then it is necessarily factorized of any other system.Comment: 5 pages, 1 figure. Proof of theorem 3 corrected e new results concerning the asymptotic regime include