773 research outputs found
Artificial General Intelligence, Existential Risk, and Human Risk Perception
Artificial general intelligence (AGI) does not yet exist, but given the pace
of technological development in artificial intelligence, it is projected to
reach human-level intelligence within roughly the next two decades. After that,
many experts expect it to far surpass human intelligence and to do so rapidly.
The prospect of superintelligent AGI poses an existential risk to humans
because there is no reliable method for ensuring that AGI goals stay aligned
with human goals. Drawing on publicly available forecaster and opinion data,
the author examines how experts and non-experts perceive risk from AGI. The
findings indicate that the perceived risk of a world catastrophe or extinction
from AGI is greater than for other existential risks. The increase in perceived
risk over the last year is also steeper for AGI than for other existential
threats (e.g., nuclear war or human-caused climate change). That AGI is a
pressing existential risk is something on which experts and non-experts agree,
but the basis for such agreement currently remains obscure
Simulator-Based Driving with Hemianopia: Detection Performance and Compensatory Behaviors on Approach to Intersections
OBJECTIVES In 22 states people with homonymous hemianopia (complete loss of the visual field on the sameside in both eyes) are explicitly prohibited from driving, as they do not meet the minimum visualfield requirements for driver licensing. However, there is little scientific evidence derived eitherfrom on-road or driving simulator studies about the safety of driving with hemianopia. If the eyeand head were kept stationary, people with hemianopia would not detect anything on the side ofthe field loss. In the real world, however, they may be able to compensate for the loss byexploring the affected (blind) side using head- and eye-scanning. It has been reported that inHolland (where driving with hemianopia is permitted), driving examiners consider increasedhead-scanning (especially on approach to intersections) to be an effective compensation forperipheral visual field defects (Coeckelbergh et al., 2002). Whether increased head-scanningwhile driving results in better detection performance has never been quantitatively investigated.We conducted a simulator-based evaluation of driving with hemianopia to investigate detectionperformance and head movement behaviors on approach to intersections.METHODSTo date, eight people with complete homonymous hemianopia (5 left and 3 right), and withoutvisual neglect or significant cognitive decline have completed the study. All had current or recentdriving experience (within the last 6 years). They completed two simulator sessions, one weekapart, driving in a high-fidelity simulator. Each session consisted of a familiarization period of30-60 minutes followed by 6 test drives (each about 12 minutes in duration). The primarysimulator task was to detect and respond (by a horn press) to the appearance of pedestrian targetsin a variety of traffic situations while driving according to the normal rules of the road. Targetsappeared randomly in locations relevant to real-world driving. There were two types of targets:âroadwayâ targets, which appeared either on the left or right of the road at small (~ 4°) or large(~14°) eccentricities from the presumed line of sight, and âintersectionâ targets, which wereplaced near or at intersections to test whether drivers were scanning effectively whenapproaching an intersection. Primary outcome measures were the percentage of targets detectedand reaction times when detected. Head movements were recorded with an inexpensive, lightweight,head-mounted optical head tracking system. Preliminary analyses of head movementbehaviors were conducted for intersections with stop or yield signs. Based on visual inspectionof the head movement plots, the number and direction of head movements were recorded and head movement scanning was graded on a 4-point scale (from 1 inadequate to 4 excellent). Inaddition, we are developing methods to automatically quantify driving skills (e.g., steering, laneposition) from the simulator data output.RESULTSDetection rates for roadway pedestrian targets were lower and reaction times longer on the blindside than the seeing side (p ⤠0.05). Blind side: median detection rate 47% (IQR 22 to 63%),median reaction time 1.65s (IQR 1.05 to 1.84s); seeing side: median detection rate 93% (IQR89% to 99%), median reaction time 0.93s, (IQR 0.88 to 1.25s). Detection rates on the blind sidewere lower at the larger eccentricity (median 23%) than the smaller eccentricity (median 66%; p= 0.01). Drivers with right hemianopia (RH) detected 83% of intersection pedestrian targets onthe extreme left of an intersection but none on the extreme right, whereas drivers with lefthemianopia (LH) detected 33% on the extreme left and 80% on the extreme right. Better headscanningscores were associated with better detection rates for intersection targets at extremepositions on the blind side (Spearman r = 0.79, p = 0.02). Two of the drivers with LH showedinadequate scanning (grade 1), failing to scan to the left at more than 60% of intersections. Therest of the drivers with LH and all three with RH demonstrated better head-scanning (grades 2-4)with some compensatory head movement behaviors. At T-intersections with no incoming roadon one side, they scanned more frequently in the direction of the âabsentâ road when it was onthe blind side (RH 40% and LH 80%) than when it was on the seeing side (RH and LH \u3c10%).When there were incoming roads on both sides, the first head scan was normally to the left forLH, but it was to the right about 30% of the time for drivers with RH.CONCLUSIONSThese results provide evidence of widely varying levels of compensation and detection abilitiesamongst drivers with hemianopia, suggesting that fitness to drive should be evaluated on anindividual basis. The preliminary finding of a relationship between head-scanning score andintersection detection performance will be further evaluated using automated methods toquantify head movement behaviors and a larger sample of drivers with hemianopia. Furthermore,we will compare head movement behaviors of drivers with hemianopia to matched controldrivers without visual field loss.REFERENCESCoeckelbergh, T.R., Brouwer, W.H., Cornelissen, F.W., van Wolffelaar, P., Kooijman, A.C.(2002). The effect of visual field defects on driving performance: a driving simulator study. ArchOphthalmol, 120, 1509-1516
How do defendants choose their trial court? Evidence for a heuristic processing account
In jurisdictions with two or more tiers of criminal courts, some defendants can choose the type of trial court to be tried in. This may involve a trade-off between the probability of acquittal/conviction and the estimated severity of sentence if convicted. For instance, in England and Wales, the lower courts have a higher conviction rate but limited sentencing powers, whereas the higher courts have a higher acquittal rate but greater sentencing powers. We examined 255 offendersâ choice of trial court type using a hypothetical scenario where innocence and guilt was manipulated. Participantsâ choices were better predicted by a lexicographic than utility maximization model. A greater proportion of âguiltyâ participants chose the lower court compared to their âinnocentâ counterparts, and estimated sentence length was more important to the former than latter group. The present findings provide further support for heuristic decision-making in the criminal justice domain, and have implications for legal policy-making
Correcting Judgment Correctives in National Security Intelligence
Intelligence analysts, like other professionals, form norms that define standards of tradecraft excellence. These norms, however, have evolved in an idiosyncratic manner that reflects the influence of prominent insiders who had keen psychological insights but little appreciation for how to translate those insights into testable hypotheses. The net result is that the prevailing tradecraft norms of best practice are only loosely grounded in the science of judgment and decision-making. The âcommon senseâ of prestigious opinion leaders inside the intelligence community has pre-empted systematic validity testing of the training techniques and judgment aids endorsed by those opinion leaders. Drawing on the scientific literature, we advance hypotheses about how current best practices could well be reducing rather than increasing the quality of analytic products. One set of hypotheses pertain to the failure of tradecraft training to recognize the most basic threat to accuracy: measurement error in the interpretation of the same data and in the communication of interpretations. Another set of hypotheses focuses on the insensitivity of tradecraft training to the risk that issuing broad-brush, one-directional warnings against bias (e.g., over-confidence) will be less likely to encourage self-critical, deliberative cognition than simple response-threshold shifting that yields the mirror-image bias (e.g., under-confidence). Given the magnitude of the consequences of better and worse intelligence analysis flowing to policy-makers, we see a compelling case for greater funding of efforts to test what actually works
Laser-modified one- and two-photon absorption:Expanding the scope of optical nonlinearity
It is shown that conventional one-photon and two-photon absorption processes can be made subject to nonlinear optical control, in each case significantly modifying the efficiency of absorption, through the effect of a secondary, off-resonant stimulus laser beam. The mechanistic origin of these laser-modified absorption processes, in which the stimulus beam emerges unchanged, is traced to higher-order terms in standard perturbation treatments. These normally insignificant terms become unusually prominent when the secondary optical stimulus is moderately intense. Employing a quantum formulation, the effects of the stimulus beam on one-photon and two-photon absorption are analyzed, and calculations are performed to determine the degree of absorption enhancement, and the form of spectral manifestation, under various laser intensities. The implications of differences in selection rules are also considered and exemplified, leading to the identification of dark states that can be populated as a result of laser-modified absorption. Attention is also drawn to the possibility of quantum nondemolition measurements, based on such a form of optical nonlinearity
Measurement of photon sorting at microwave frequencies in a cavity array metasurface
PublishedJournal ArticleWe present experimental results demonstrating the spatial sorting of incoming radiation in two spectral ranges. A metasurface composed of a periodically patterned metal of subwavelength thickness with dielectric inclusions concentrates and localizes electromagnetic fields near the surface. Light of the separate spectral bands is channeled into different geometrically tuned cavities within each spatially repeating unit cell. Excitation of cavity modes facilitates this simultaneous spatial- and spectral-selective absorption. The measured reflection and field profiles are presented and the spectral and spatial selectivity are shown. A method to apply these concepts to split radiation into three spectral bands is also proposed.This work was supported in part by the AFOSR Bioenergy project (FA9550-10-1-0350), in part by the NSF Industry/University Cooperative Research Center for Metamaterials (IIP-1068028), and in part by the EPSRC, U.K. funding through the QUEST project (ref: EP/I034548/1)
Precise Estimates of the Physical Parameters for the Exoplanet System HD-17156 Enabled by HST FGS Transit and Asteroseismic Observations
We present observations of three distinct transits of HD 17156b obtained with
the Fine Guidance Sensors (FGS) on board the Hubble Space Telescope} (HST). We
analyzed both the transit photometry and previously published radial velocities
to find the planet-star radius ratio R_p/R_s = 0.07454 +/- 0.00035, inclination
i=86.49 +0.24/-0.20 deg, and scaled semi-major axis a/R = 23.19 +0.32/-0.27.
This last value translates directly to a mean stellar density determination of
0.522 +0.021/-0.018 g cm^-3. Analysis of asteroseismology observations by the
companion paper of Gilliland et al. (2009) provides a consistent but
significantly refined measurement of the stellar mean density. We compare
stellar isochrones to this density estimate and find M_s = 1.275 +/- 0.018
M_sun and a stellar age of $3.37 +0.20/-0.47 Gyr. Using this estimate of M_s
and incorporating the density constraint from asteroseismology, we model both
the photometry and published radial velocities to estimate the planet radius
R_p= 1.0870 +/- 0.0066 Jupiter radii and the stellar radius R_s = 1.5007 +/-
0.0076 R_sun. The planet radius is larger than that found in previous studies
and consistent with theoretical models of a solar-composition gas giant of the
same mass and equilibrium temperature. For the three transits, we determine the
times of mid-transit to a precision of 6.2 s, 7.6 s, and 6.9 s, and the transit
times for HD 17156 do not show any significant departures from a constant
period. The joint analysis of transit photometry and asteroseismology presages
similar studies that will be enabled by the NASA Kepler Mission.Comment: Accepted for publication to Ap
Boosting intelligence analystsâ judgment accuracy: what works, what fails?
A routine part of intelligence analysis is judging the probability of alternative hypotheses given available evidence. Intelligence organizations advise analysts to use intelligence-tradecraft methods such as Analysis of Competing Hypotheses (ACH) to improve judgment, but such methods have not been rigorously tested. We compared the evidence evaluation and judgment accuracy of a group of intelligence analysts who were recently trained in ACH and then used it on a probability judgment task to another group of analysts from the same cohort that were neither trained in ACH nor asked to use any specific method. Although the ACH group assessed information usefulness better than the control group, the control group was a little more accurate (and coherent) than the ACH group. Both groups, however, exhibited suboptimal judgment and were susceptible to unpacking effects. Although ACH failed to improve accuracy, we found that recalibration and aggregation methods substantially improved accuracy. Specifically, mean absolute error (MAE) in analystsâ probability judgments decreased by 61% after first coherentizing their judgments (a process that ensures judgments respect the unitarity axiom) and then aggregating their judgments. The findings cast doubt on the efficacy of ACH, and show the promise of statistical methods for boosting judgment quality in intelligence and other organizations that routinely produce expert judgments
Hawai`i Supernova Flows: A Peculiar Velocity Survey Using Over a Thousand Supernovae in the Near-Infrared
We introduce the Hawai`i Supernova Flows project and present summary
statistics of the first 1218 astronomical transients observed, 669 of which are
spectroscopically classified Type Ia Supernovae (SNe Ia). Our project is
designed to obtain systematics-limited distances to SNe Ia while consuming
minimal dedicated observational resources. This growing sample will provide
increasing resolution into peculiar velocities as a function of position on the
sky and redshift, allowing us to more accurately map the structure of dark
matter. This can be used to derive cosmological parameters such as
and can be compared with large scale flow maps from other methods such as
luminosity-line width or luminosity-velocity dispersion correlations in
galaxies. Additionally, our photometry will provide a valuable test bed for
analyses of SNe Ia incorporating near-infrared data. In this survey paper, we
describe the methodology used to select targets, collect and reduce data, and
calculate distances.Comment: 33 pages, 23 figure
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