5,360 research outputs found
Disappearing private reputations in long-run relationships
For games of public reputation with uncertainty over types and imperfect public monitoring, Cripps et al. [Imperfect monitoring and impermanent reputations, Econometrica 72 (2004) 407–432] showed that an informed player facing short-lived uninformed opponents cannot maintain a permanent reputation for playing a strategy that is not part of an equilibrium of the game without uncertainty over types. This paper extends that result to games in which the uninformed player is long-lived and has private beliefs, so that the informed player's reputation is private. The rate at which reputations disappear is uniform across equilibria and reputations also disappear in sufficiently long discounted finitely repeated games
Common learning
Consider two agents who learn the value of an unknown parameter by observing a sequence of private signals. The signals are independent and identically distributed across time but not necessarily across agents. We show that when each agent's signal space is finite, the agents will commonly learn the value of the parameter, that is, that the true value of the parameter will become approximate common knowledge. The essential step in this argument is to express the expectation of one agent's signals, conditional on those of the other agent, in terms of a Markov chain. This allows us to invoke a contraction mapping principle ensuring that if one agent's signals are close to those expected under a particular value of the parameter, then that agent expects the other agent's signals to be even closer to those expected under the parameter value. In contrast, if the agents' observations come from a countably infinite signal space, then this contraction mapping property fails. We show by example that common learning can fail in this case
Mesoscopic Thermovoltage Measurement Design
Quantitative thermoelectric measurements in the mesoscopic regime require
accurate knowledge of temperature, thermovoltage, and device energy scales. We
consider the effect of a finite load resistance on thermovoltage measurements
of InAs/InP heterostructure nanowires. Load resistance and ac attenuation
distort the measured thermovoltage therefore complicating the evaluation of
device performance. Understanding these effects improves experimental design
and data interpretation.Comment: 2 pages, 3 figure
Helping teachers teach : exploring student needs in elementary classrooms
Unmet student needs negatively affect the ability of teachers to create a successful learning environment for all students. Some of these needs include students not being at the academic levels they should be and special education students not getting individualized attention. As a future educator, I sought to discover what could be done to help teachers address these needs in order to create a better classroom environment. Two teachers from the same elementary school were interviewed about student needs, how student needs impact their teaching ability, and what is being done to assist theses needs. Preliminary data analyses indicate that more participation is needed from within both the school and the outside community in classrooms and additional attention given to special education students. Thus, it has been learned that schools benefit most from further assistance, participation, and collaboration by teachers, parents, and other involved community members
Large Magnetoresistance in Co/Ni/Co Ferromagnetic Single Electron Transistors
We report on magnetotransport investigations of nano-scaled ferromagnetic
Co/Ni/Co single electron transistors. As a result of reduced size, the devices
exhibit single electron transistor characteristics at 4.2K. Magnetotransport
measurements carried out at 1.8K reveal tunneling magnetoresistance (TMR)
traces with negative coercive fields, which we interpret in terms of a
switching mechanism driven by the shape anisotropy of the central wire-like Ni
island. A large TMR of about 18% is observed within a finite source-drain bias
regime. The TMR decreases rapidly with increasing bias, which we tentatively
attribute to excitation of magnons in the central island.Comment: 12 pages (including 4 figures). Accepted for publishing on AP
Probing confined phonon modes by transport through a nanowire double quantum dot
Strong radial confinement in semiconductor nanowires leads to modified
electronic and phononic energy spectra. We analyze the current response to the
interplay between quantum confinement effects of the electron and phonon
systems in a gate-defined double quantum dot in a semiconductor nanowire. We
show that current spectroscopy of inelastic transitions between the two quantum
dots can be used as an experimental probe of the confined phonon environment.
The resulting discrete peak structure in the measurements is explained by
theoretical modeling of the confined phonon mode spectrum, where the
piezoelectric coupling is of crucial importance.Comment: 4 pages, 4 figures; final versio
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