810 research outputs found
Nearsighted justice
Chapter 11 structures complex negotiations between creditors and debtors that are overseen by a bankruptcy court. This paper identifies conditions under which it is optimal for the court to sometimes err in determining whether a firm should be liquidated. Such errors can affect the optimal action choices by both good and bad entrepreneurs. We first characterize the optimal error rate without renegotiation, providing conditions under which it is optimal for the court both to sometimes mistakenly liquidate "good firms," but not "bad firms." When creditors and debtors can renegotiate to circumvent an error-riven court and creditors have all of the bargaining power, we show that for a broad class of action choices, a blind court--one that ignores all information and hence is equally likely to liquidate a good firm as a bad one--is optimal.Bankruptcy
Universal Protocols for Information Dissemination Using Emergent Signals
We consider a population of agents which communicate with each other in a
decentralized manner, through random pairwise interactions. One or more agents
in the population may act as authoritative sources of information, and the
objective of the remaining agents is to obtain information from or about these
source agents. We study two basic tasks: broadcasting, in which the agents are
to learn the bit-state of an authoritative source which is present in the
population, and source detection, in which the agents are required to decide if
at least one source agent is present in the population or not.We focus on
designing protocols which meet two natural conditions: (1) universality, i.e.,
independence of population size, and (2) rapid convergence to a correct global
state after a reconfiguration, such as a change in the state of a source agent.
Our main positive result is to show that both of these constraints can be met.
For both the broadcasting problem and the source detection problem, we obtain
solutions with a convergence time of rounds, w.h.p., from any
starting configuration. The solution to broadcasting is exact, which means that
all agents reach the state broadcast by the source, while the solution to
source detection admits one-sided error on a -fraction of the
population (which is unavoidable for this problem). Both protocols are easy to
implement in practice and have a compact formulation.Our protocols exploit the
properties of self-organizing oscillatory dynamics. On the hardness side, our
main structural insight is to prove that any protocol which meets the
constraints of universality and of rapid convergence after reconfiguration must
display a form of non-stationary behavior (of which oscillatory dynamics are an
example). We also observe that the periodicity of the oscillatory behavior of
the protocol, when present, must necessarily depend on the number ^\\# X of
source agents present in the population. For instance, our protocols inherently
rely on the emergence of a signal passing through the population, whose period
is \Theta(\log \frac{n}{^\\# X}) rounds for most starting configurations. The
design of clocks with tunable frequency may be of independent interest, notably
in modeling biological networks
Gambling for dollars: Strategic hedge fund manager investment
Hedge fund managers differ in ability and investors want to distinguish good ones from bad. Via the design of their investment strategies, better fund managers want to ease this inference problem while worse fund managers want to complicate it. We impose only the minimal restrictions on the nature the investment strategies that, on average, returns reflect the hedge fund manager's ability and that returns be bounded from below, and solve for the set of equilibria that emerge. We then show that under a variety of equilibrium refinements, a unique equilibrium obtains. In this equilibrium, investors set a cutoff standard for providing capital to a hedge fund: and invest if and only if returns exceed this cutoff. This induces less able hedge fund managers to adopt risky investment strategies that maximize the probability of meeting this cutoff by risking large losses if they fail. Over time, as investors learn about a hedge fund manager's ability and less able hedge fund managers are stochastically weeded out, investors set less demanding re-investment standards. Our economy reconciles many facts regarding hedge fund performance. For example, in a regression with fixed hedge fund manager effects, returns of more experienced hedge fund managers decline, even though the expected profits of investors rise with the hedge fund manager's experience; more experienced hedge funds deliver less volatile returns; persistence of returns is greater for better hedge funds; hedge fund failure rates are initially very high, but fall sharply with hedge fund manager experience; returns of exiting hedge funds are substantially worse than historical returns; and the longer is an investor's horizon, the lower is the expected return of the hedge funds in which he invests
The Impact of Human Assurance on Satellite Operations
Mission assurance is a method to guarantee mission success against a known set of risks; mission assurance is generally represented as a probability against a threshold of acceptable performance. Human assurance can be considered as the likelihood of acceptable operator performance given a set of conditions that include the operator, the system, and the environment. Standard mission assurance models tend to assume a qualified crew, but do not include other aspects of the internal or external environment that may impact the reliability of the human operator. A human assurance model can be created that allows the exploration of the variability in operator performance due to the likelihood of different risks. An example human assurance model has been created for the detection of adverse trending satellite data and the need to modify the existing mission schedule to address the satellite emergency. The model leverages the Human Viewpoint framework to capture the human-focused data within the mission context. From this data, sources of risk can be identified for the socio-technical system and a risk framework developed. The resulting risk model allows exploration of the characteristics of both the operator and the operating environment, as well as the impact of organizational mitigations, on the likelihood that the socio-technical system will meet mission assurance thresholds. The method provided can be used to identify the limitations of human system performance against the established criteria
Social Media & Teacher Professional Development
The idea of social mediaâs existing application and future potential for professional development drives a growing subset of academic research. As we encourage preservice and inservice teachers to engage in these platforms to hone or refine their classroom practice, a number of questions emerge: How do we assess participation in these spaces? What uses in particular should we recommend? Further, the very notion of conducting research in these spaces also poses interesting questions. From methodologies to frameworks, commonly accepted practices help shape the future of the field. Lastly, the issue of privacy and policy poses perhaps the most significant area for attention. The intent of this panel discussion is generate conversation on how future research and application on social media usage and research might evolve over time
Ariel - Volume 12(13) Number 2
Editor
Gary Fishbein
Production & Business Manager
Rich Davis
Layout Editor
Lynn Solomon
Assistant Layout Editors
Bessann Dawson
Tonie Kline
Becky A. Zuurbier
Photography Editor
Ben Alma
Giant coherence in driven systems
We study the noise-induced currents and reliability or coherence of transport
in two different classes of rocking ratchets. For this, we consider the motion
of Brownian particles in the over damped limit in both adiabatic and
non-adiabatic regimes subjected to unbiased temporally symmetric and asymmetric
periodic driving force. In the case of a time symmetric driving, we find that
even in the presence of a spatially symmetric simple sinusoidal potential,
highly coherent transport occurs. These ratchet systems exhibit giant coherence
of transport in the regime of parameter space where unidirectional currents in
the deterministic case are observed. Outside this parameter range, i.e., when
current vanishes in the deterministic regime, coherence in transport is very
low. The transport coherence decreases as a function of temperature and is a
non-monotonic function of the amplitude of driving. The transport becomes
unreliable as we go from the adiabatic to the non-adiabatic domain of
operation.Comment: 15 pages, 9 figures, replaced by the version to appear in JSTA
The MANTA: An RPV design to investigate forces and moments on a lifting surface
The overall goal was to investigate and exploit the advantages of using remotely powered vehicles (RPV's) for in-flight data collection at low Reynold's numbers. The data to be collected is on actual flight loads for any type of rectangular or tapered airfoil section, including vertical and horizontal stabilizers. The data will be on a test specimen using a force-balance system which is located forward of the aircraft to insure an undisturbed air flow over the test section. The collected data of the lift, drag and moment of the test specimen is to be radioed to a grand receiver, thus providing real-time data acquisition. The design of the mission profile and the selection of the instrumentation to satisfy aerodynamic requirements are studied and tested. A half-size demonstrator was constructed and flown to test the flight worthiness of the system
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