2,404 research outputs found
Computable Artificial General Intelligence
Artificial general intelligence (AGI) may herald our extinction, according to
AI safety research. Yet claims regarding AGI must rely upon mathematical
formalisms -- theoretical agents we may analyse or attempt to build. AIXI
appears to be the only such formalism supported by proof that its behaviour is
optimal, a consequence of its use of compression as a proxy for intelligence.
Unfortunately, AIXI is incomputable and claims regarding its behaviour highly
subjective. We argue that this is because AIXI formalises cognition as taking
place in isolation from the environment in which goals are pursued (Cartesian
dualism). We propose an alternative, supported by proof and experiment, which
overcomes these problems. Integrating research from cognitive science with AI,
we formalise an enactive model of learning and reasoning to address the problem
of subjectivity. This allows us to formulate a different proxy for
intelligence, called weakness, which addresses the problem of incomputability.
We prove optimal behaviour is attained when weakness is maximised. This proof
is supplemented by experimental results comparing weakness and description
length (the closest analogue to compression possible without reintroducing
subjectivity). Weakness outperforms description length, suggesting it is a
better proxy. Furthermore we show that, if cognition is enactive, then
minimisation of description length is neither necessary nor sufficient to
attain optimal performance, undermining the notion that compression is closely
related to intelligence. However, there remain open questions regarding the
implementation of scale-able AGI. In the short term, these results may be best
utilised to improve the performance of existing systems. For example, our
results explain why Deepmind's Apperception Engine is able to generalise
effectively, and how to replicate that performance by maximising weakness.Comment: Experiment code available on TechRxiv:
https://www.techrxiv.org/articles/preprint/Computable_Artificial_General_Intelligence/1974019
Should the FDIC worry about the FHLB? the impact of Federal Home Loan Bank advances on the Bank Insurance Fund
Does growing commercial-bank reliance on Federal Home Loan Bank (FHLBank) advances increase expected losses to the Bank Insurance Fund (BIF)? Our approach to this question begins by modeling the link between advances and expected losses. We then quantify the effect of advances on default probability with a CAMELS-downgrade model. Finally, we assess the impact on loss-given-default by estimating resolution costs in two scenarios: the liquidation of all banks with failure probabilities above two percent and the liquidation of all banks with advance-to-asset ratios above 15 percent. The evidence points to non-trivial increases in expected losses. The policy implication is that the FDIC should price FHLBank-related exposures.Banks and banking ; Financial institutions ; Deposit insurance
Support Department Cost Allocations in the Georgia Healthcare Industry
This study examines support department cost allocations in the Healthcare Industry. The topic is of current interest to both accountants and to healthcare administrators because of recent innovations in the design of management accounting systems. Using a survey of Georgian healthcare firms, the results indicate that sophisticated support cost methods are used less than may be expected given the complexity of the healthcare firms\u27 operations. This result is documented despite the historical presence of support cost allocations through such industry practice as Medicare cost reports. Respondents indicate that the employment of cost allocation methods is determined internally by the financial management
Saffman-Taylor fingers with kinetic undercooling
The mathematical model of a steadily propagating Saffman-Taylor finger in a
Hele-Shaw channel has applications to two-dimensional interacting streamer
discharges which are aligned in a periodic array. In the streamer context, the
relevant regularisation on the interface is not provided by surface tension,
but instead has been postulated to involve a mechanism equivalent to kinetic
undercooling, which acts to penalise high velocities and prevent blow-up of the
unregularised solution. Previous asymptotic results for the Hele-Shaw finger
problem with kinetic undercooling suggest that for a given value of the kinetic
undercooling parameter, there is a discrete set of possible finger shapes, each
analytic at the nose and occupying a different fraction of the channel width.
In the limit in which the kinetic undercooling parameter vanishes, the fraction
for each family approaches 1/2, suggesting that this 'selection' of 1/2 by
kinetic undercooling is qualitatively similar to the well-known analogue with
surface tension. We treat the numerical problem of computing these
Saffman-Taylor fingers with kinetic undercooling, which turns out to be more
subtle than the analogue with surface tension, since kinetic undercooling
permits finger shapes which are corner-free but not analytic. We provide
numerical evidence for the selection mechanism by setting up a problem with
both kinetic undercooling and surface tension, and numerically taking the limit
that the surface tension vanishes.Comment: 10 pages, 6 figures, accepted for publication by Physical Review
Proposal for an IMLS Collection Registry and Metadata Repository
The University of Illinois at Urbana-Champaign proposes to design, implement, and research a collection-level registry and item-level metadata repository service that will aggregate information about digital collections and items of digital content created using funds from Institute of Museum and Library Services (IMLS) National Leadership Grants. This work will be a collaboration by the University Library and the Graduate School of Library and Information Science. All extant digital collections initiated or augmented under IMLS aegis from 1998 through September 30, 2005 will be included in the proposed collection registry. Item-level metadata will be harvested from collections making such content available using the Open Archives Initiative Protocol for Metadata Harvesting (OAI PMH). As part of this work, project personnel, in cooperation with IMLS staff and grantees, will define and document appropriate metadata schemas, help create and maintain collection-level metadata records, assist in implementing OAI compliant metadata provider services for dissemination of item-level metadata records, and research potential benefits and issues associated with these activities. The immediate outcomes of this work will be the practical demonstration of technologies that have the potential to enhance the visibility of IMLS funded online exhibits and digital library collections and improve discoverability of items contained in these resources. Experience gained and research conducted during this project will make clearer both the costs and the potential benefits associated with such services. Metadata provider and harvesting service implementations will be appropriately instrumented (e.g., customized anonymous transaction logs, online questionnaires for targeted user groups, performance monitors). At the conclusion of this project we will submit a final report that discusses tasks performed and lessons learned, presents business plans for sustaining registry and repository services, enumerates and summarizes potential benefits of these services, and makes recommendations regarding future implementations of these and related intermediary and end user interoperability services by IMLS projects.unpublishednot peer reviewe
Taking a Constitutional: A Walking Tour of Boston\u27s Constitutional History
A tour supplementing The Freedom Trail and The Black Heritage Trail with sites and information of special relevance to the Bicentennial of the United States Constitution
Continuous-Variable Quantum Key Distribution using Thermal States
We consider the security of continuous-variable quantum key distribution
using thermal (or noisy) Gaussian resource states. Specifically, we analyze
this against collective Gaussian attacks using direct and reverse
reconciliation where both protocols use either homodyne or heterodyne
detection. We show that in the case of direct reconciliation with heterodyne
detection, an improved robustness to channel noise is achieved when large
amounts of preparation noise is added, as compared to the case when no
preparation noise is added. We also consider the theoretical limit of infinite
preparation noise and show a secure key can still be achieved in this limit
provided the channel noise is less than the preparation noise. Finally, we
consider the security of quantum key distribution at various electromagnetic
wavelengths and derive an upper bound related to an entanglement-breaking
eavesdropping attack and discuss the feasibility of microwave quantum key
distribution.Comment: 12 pages, 11 figures. Updated from published version with some minor
correction
Nuclear magnetic resonance spectroscopy: An experimentally accessible paradigm for quantum computing
We present experimental results which demonstrate that nuclear magnetic
resonance spectroscopy is capable of efficiently emulating many of the
capabilities of quantum computers, including unitary evolution and coherent
superpositions, but without attendant wave-function collapse. Specifically, we
have: (1) Implemented the quantum XOR gate in two different ways, one using
Pound-Overhauser double resonance, and the other using a spin-coherence double
resonance pulse sequence; (2) Demonstrated that the square root of the
Pound-Overhauser XOR corresponds to a conditional rotation, thus obtaining a
universal set of gates; (3) Devised a spin-coherence implementation of the
Toffoli gate, and confirmed that it transforms the equilibrium state of a
four-spin system as expected; (4) Used standard gradient-pulse techniques in
NMR to equalize all but one of the populations in a two-spin system, so
obtaining the pseudo-pure state that corresponds to |00>; (5) Validated that
one can identify which basic pseudo-pure state is present by transforming it
into one-spin superpositions, whose associated spectra jointly characterize the
state; (6) Applied the spin-coherence XOR gate to a one-spin superposition to
create an entangled state, and confirmed its existence by detecting the
associated double-quantum coherence via gradient-echo methods.Comment: LaTeX + epsfig + amsmath packages, 27 pages, 12 figures, to appear in
Physica D; revision updates list of authors and reference
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