513 research outputs found
Maximally epistemic interpretations of the quantum state and contextuality
We examine the relationship between quantum contextuality (in both the
standard Kochen-Specker sense and in the generalised sense proposed by
Spekkens) and models of quantum theory in which the quantum state is maximally
epistemic. We find that preparation noncontextual models must be maximally
epistemic, and these in turn must be Kochen-Specker noncontextual. This implies
that the Kochen-Specker theorem is sufficient to establish both the
impossibility of maximally epistemic models and the impossibility of
preparation noncontextual models. The implication from preparation
noncontextual to maximally epistemic then also yields a proof of Bell's theorem
from an EPR-like argument.Comment: v1: 4 pages, revTeX4.1, some overlap with arXiv:1207.7192. v2:
Changes in response to referees including revised proof of theorem 1, more
rigorous discussion of measure theoretic assumptions and extra introductory
materia
Bioethical Catch-22: The Moratorium on Federal Funding of Fetal Tissue Transplantation Research and the NIH Revitalization Amendments
International Diversification with American Depository Receipts (ADRs);
It is already well known that U.S. investors can achieve higher gains by investing directly in emerging markets (De Santis, 1997). Given the opportunity to invest directly in the shares of stocks in the developed (DCs) and emerging (EM) markets, it is interesting to know whether the U.S. investors can potentially gain any benefits by investing in ADRs. We test both index models, and SDF-based model.Our findings show that U.S. investors needed to invest in both ADRs and country portfolios in developed in the eighties, and in Latin American countries in early nineties. During the early and late nineties, we find substitutability between ADRs and country portfolios in DCs. As more and more ADRs are enlisted in the US market from developed countries over time, the ADRs become substitutes to country. Similarly, countries with higher number of ADRs irrespective of regions show the same pattern of substitutability between ADRs and country indices. However, such substitutability does not exist for countries with the highest number of ADRs by the end of sample period, 2001. On the other hand, U.S. investors can achieve the diversification benefits by investing ADRs along with U.S. market index in Asia. The significant marginal contribution of one-third of developed countries requires investment in ADRs and U.S. market in the developed countries. And investors do not need to hold both ADRs and country as it was the case in the eighties. On the other hand, investors need to hold both ADRs and country portfolios in most of the Asian countries to achieve diversification benefits at margin
Incorporating Active Adjustment into a Financing Based Model of Capital Structure
The conventional partial adjustment model, which focuses on leverage evolution, has difficulty identifying deliberate capital structure adjustments as it confounds financing decisions with the mechanical autocorrelation of leverage. We propose and estimate a financing-based partial adjustment model that separates the effects of financing decisions on leverage evolution from mechanical evolution. The speed of adjustment (SOA) is firm specific and stochastic, and active targeting of capital structure has a multiplier effect that depends on the size of financial deficit. Overall, we find expected SOA from active rebalancing(30%) more than doubles what is expected from mechanical mean reversion alone (13%)
Energy-Efficient Algorithms
We initiate the systematic study of the energy complexity of algorithms (in
addition to time and space complexity) based on Landauer's Principle in
physics, which gives a lower bound on the amount of energy a system must
dissipate if it destroys information. We propose energy-aware variations of
three standard models of computation: circuit RAM, word RAM, and
transdichotomous RAM. On top of these models, we build familiar high-level
primitives such as control logic, memory allocation, and garbage collection
with zero energy complexity and only constant-factor overheads in space and
time complexity, enabling simple expression of energy-efficient algorithms. We
analyze several classic algorithms in our models and develop low-energy
variations: comparison sort, insertion sort, counting sort, breadth-first
search, Bellman-Ford, Floyd-Warshall, matrix all-pairs shortest paths, AVL
trees, binary heaps, and dynamic arrays. We explore the time/space/energy
trade-off and develop several general techniques for analyzing algorithms and
reducing their energy complexity. These results lay a theoretical foundation
for a new field of semi-reversible computing and provide a new framework for
the investigation of algorithms.Comment: 40 pages, 8 pdf figures, full version of work published in ITCS 201
Fluctuation Theorem with Information Exchange: Role of Correlations in Stochastic Thermodynamics
We establish the fluctuation theorem in the presence of information exchange
between a nonequilibrium system and other degrees of freedom such as an
observer and a feedback controller, where the amount of information exchange is
added to the entropy production. The resulting generalized second law sets the
fundamental limit of energy dissipation and energy cost during the information
exchange. Our results apply not only to feedback-controlled processes but also
to a much broader class of information exchanges, and provides a unified
framework of nonequilibrium thermodynamics of measurement and feedback control.Comment: To appear in PR
Opening up the Quantum Three-Box Problem with Undetectable Measurements
One of the most striking features of quantum mechanics is the profound effect
exerted by measurements alone. Sophisticated quantum control is now available
in several experimental systems, exposing discrepancies between quantum and
classical mechanics whenever measurement induces disturbance of the
interrogated system. In practice, such discrepancies may frequently be
explained as the back-action required by quantum mechanics adding quantum noise
to a classical signal. Here we implement the 'three-box' quantum game of
Aharonov and Vaidman in which quantum measurements add no detectable noise to a
classical signal, by utilising state-of-the-art control and measurement of the
nitrogen vacancy centre in diamond.
Quantum and classical mechanics then make contradictory predictions for the
same experimental procedure, however classical observers cannot invoke
measurement-induced disturbance to explain this discrepancy. We quantify the
residual disturbance of our measurements and obtain data that rule out any
classical model by > 7.8 standard deviations, allowing us for the first time to
exclude the property of macroscopic state-definiteness from our system. Our
experiment is then equivalent to a Kochen-Spekker test of quantum
non-contextuality that successfully addresses the measurement detectability
loophole
2005 Revised Omaha Economic Development Plan: Plan for Northeast Omaha
The 2005 Revised OEDP provides OEDC with current data and analysis to initiate and complete a strategic process to develop an action plan for community and economic development activities and projects.
The 2005 Revised Overall Economic Development Plan (OEDP) prepared by the Center for Public Affairs Research (CPAR) at the University of Nebraska at Omaha (UNO) for the Omaha Economic Development Corporation (OEDC) replaces the original OEDP first prepared in 1978. While a variety of revisions and updates over the years helped keep the original OEDP relatively current and helpful in development activities, in 2005 OEDC President Alvin Goodwin commissioned CPAR to provide a new basic planning document for the organization. Working with OEDC staff, and using the original OEDP as a framework, faculty and staff from CPAR, with the assistance of UNO graduate students, collected and analyzed data for the 2005 Revised Overall Economic Development Plan. The Revised OEDP retains and updates several of the sections from the original Plan but also adds new sections. Overall economic development plans contain a wealth of information about the demographic, social, and economic characteristics of the geographic area targeted for development by a community development corporation (CDC). CDCs, like the Omaha Economic Development Corporation, engage in many and varied community and economic development projects in its service area, and the overall economic development plan provides needed information to implement these projects. For example, the OEDP helps the community development corporation identify community needs as well as opportunities for business and economic development. Data from the OEDP can also be utilized for marketing and promotional purposes to attract new firms and customers. The OEDP serves as a source of information for formulating broad, long-term organizational goals, as well as specific, short-term development strategies and actions. Finally, the OEDP helps coordinate development activities, plans, and projects among the range of other organizations working in or adjacent to the target area
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