Separation Violations Research Articles

Discrete Symmetries CP, T, CPT

The role of Symmetry Breaking mechanisms to search for New Physics is of highest importance. We discuss the status and prospects of the Discrete Symmetries CP, T, CPT looking for their separate Violation in LHC experiments and meson factories.

Combined schemes for signature and encryption: The public-key and the identity-based setting

Consider a scenario in which parties use a public-key encryption scheme and a signature scheme with a single public key/private key pair—so the private key sk is used for both signing and decrypting. Such a simultaneous use of a key is in general considered poor cryptographic practice, but from an efficiency point of view looks attractive.We offer security notions to analyze such violations of key separation. For both the identity- and the non-identity-based setting, we show that—although being insecure in general—for schemes of interest the resulting combined scheme can offer strong security guarantees.

An Experimental Test of the Anscombe–Aumann Monotonicity Axiom

Most models of ambiguity aversion satisfy the Anscombe–Aumann monotonicity axiom. Monotonicity implies a weak form of separability of preferences across events that occur with unknown probability. We construct a test of weak separability by modifying the Allais paradox, adapting it to the Anscombe–Aumann framework. Three experimental studies are conducted. Study 1 finds frequent, systematic violations of weak separability in the lab. These findings replicate in study 2, where we employ a subject pool of online workers and use a natural rather than an artificial source of uncertainty. Investigating a potential explanation of the violations, study 3 suggests that the certainty effect plays a major role. Data and the web appendix are available at https://doi.org/10.1287/mnsc.2017.3010 . This paper was accepted by Han Bleichrodt, decision analysis.

Categorization training increases the perceptual separability of novel dimensions

Perceptual separability is a foundational concept in cognitive psychology. A variety of research questions in perception – particularly those dealing with notions such as “independence,” “invariance,” “holism,” and “configurality” – can be characterized as special cases of the problem of perceptual separability. Furthermore, many cognitive mechanisms are applied differently to perceptually separable dimensions than to non-separable dimensions. Despite the importance of dimensional separability, surprisingly little is known about its origins. Previous research suggests that categorization training can lead to learning of novel dimensions, but it is not known whether the separability of such dimensions also increases with training. Here, we report evidence that training in a categorization task increases perceptual separability of the category-relevant dimension according to a variety of tests from general recognition theory (GRT). In Experiment 1, participants who received pre-training in a categorization task showed reduced Garner interference effects and reduced violations of marginal invariance, compared to participants who did not receive such pre-training. Both of these tests are theoretically related to violations of perceptual separability. In Experiment 2, participants who received pre-training in a categorization task showed reduced violations of perceptual separability according to a model-based analysis of data using GRT. These results are at odds with the common assumption that separability and independence are fixed, hardwired characteristics of features and dimensions.

Plasmon decay and thermal transport from spin-charge coupling in generic Luttinger liquids.

We discuss the violation of spin-charge separation in generic nonlinear Luttinger liquids and investigate its effect on the relaxation and thermal transport of genuine spin-1/2 electron liquids in ballistic quantum wires. We identify basic scattering processes compatible with the symmetry of the problem and conservation laws that lead to the decay of plasmons into the spin modes. We derive a closed set of coupled kinetic equations for the spin-charge excitations and solve the problem of thermal conductance of interacting electrons for an arbitrary relation between the quantum wire length and spin-charge thermalization length.

On the Internal Representation of Numerical Magnitude and Physical Size

A nascent idea in the numerical cognition literature--the analogical hypothesis (Pinel, Piazza, Bihan, & Dehaene, 2004)--assumes a common noisy code for the representation of symbolic (e.g., numerals) and nonsymbolic (e.g., numerosity, physical size, luminance) magnitudes. The present work subjected this assumption to various tests from the perspective of General Recognition Theory (GRT; Ashby &Townsend, 1986)--a multidimensional extension of Signal Detection Theory (Green & Swets, 1966). The GRT was applied to the dimensions of numerical magnitude and physical size with the following goals: (a) characterizing the internal representation of these dimensions in the psychological space, and (b) assessing various types of (in)dependence and separability governing the perception of these dimensions. The results revealed various violations of independence and separability with Stroop incongruent, but not with Stroop congruent stimuli. The outcome suggests that there are deep differences in architecture between Stroop congruent and incongruent stimuli that reach well beyond the semantic relationship involved.

Error distributions in aircraft position determination

The paper deals with the problems of determining aircraft coordinates. The widely used Gaussian distribution does not make it possible to analyze extremely rare events with certainty. The ICAO- recommended double-exponent distribution does not meet the requirements of accuracy either. It is, therefore, necessary to look for new distributions. The paper gives examples of such distributions as well as examples of solving problems of detecting violations of separation.

Analysis of Air Traffic Control Command Entries and the Impact on Decision Support Tool Performance

In the en route environment, air traffic control is responsible for maintaining separation between aircraft with the assistance of many decision support tools (DSTs), such as Conflict Probe and Trajectory Predictor. Conflict Probe predicts potential airspace conflicts and notifies the controller of the impending separation violation, while Trajectory Predictor predicts more accurate aircraft position. In the Next Generation Air Transportation System (NextGen) environment, it is envisioned that Conflict Probe performance will be improved by adding more accurate aircraft and pilot intent data, better air traffic surveillance, and 4D trajectory-based operations.This paper investigates the effect and sensitivity of a proposed NextGen improvement on the Conflict Probe. A quantitative study is designed to examine integration of the text in the 4th line of the flight data block, which currently serves as an optional note field for air traffic controllers, into the en route DST to create new trajectories. The new, more accurate trajectories are compared against the original baseline trajectories to determine aircraft position accuracy improvements from the Trajectory Predictor, and false alert reductions from the Conflict Probe. The study findings quantitatively demonstrate that heading amendments increase trajectory accuracy by reducing horizontal error as much as 6.21nm, cross track error by 3.65nm, and along track error by 3.64nm on the first day. Speed amendments, noted in 4th line of the flight data block, decrease by 10.3% the overall number of false alerts generated by the Conflict Probe.

Dynamic regime of electron transport in correlated one-dimensional conductor with defect

The electron transport in a 1D conductor with an isolated local defect such as an impurity or a non-adiabatic contact is studied theoretically. A new regime of conduction in correlated 1D systems is predicted beyond the well-known regime of tunneling resulting in the power-law I–V-curves. In this regime a quantum wire becomes “opened” at a voltage bias above the threshold value determined by 2kF-component of impurity potential renormalized by fluctuations, giving rise to a rapid increase of the dc current, I¯, accompanied by ac oscillations of frequency f=I¯/e. Manifestations of the effect resemble the Coulomb blockade and the Josephson effect. The spin bias applied to the system affects the I–V curves due to violation of the spin-charge separation at the defect site. The 1D conductor is described in terms of the Tomonaga–Luttinger Hamiltonian with short range or long-range Coulomb interaction by means of the bosonization technique. We derive boundary conditions that take into account relaxation in the leads and permit to solve non-equilibrium problems. Charge fluctuations are studied by means of Gaussian model which can be justified strictly in the limit of large voltages or strong inter-electronic repulsion. Spin fluctuations are taken into account strictly by means of the refermionization technique applicable in the case of spin-rotation invariant interaction.

Direct perception biases with maritime navigation displays of collision risk

Maritime navigation systems need to assist judgments about safe separations and avoidance manoeuvres. Collision Danger Sectors (CDS) are a proposed visualisation for radar displays intended to support the direct perception of impending traffic separation violations. We report an evaluation of the CDS display format in a laboratory study of navigation decision-making involving judgments of safe separations. Contrary to prediction, the CDS display did not bias decision making towards neglecting rules about track crossing. The CDS display did encourage excessive avoidance manoeuvres at higher angles of approach. A marked increase in response time with angle of approach was also evident, indicating a need for decision-aiding.

The Impacts of Inversion and Thatcherisation on Face Processing: Mapping between ERP and GRT

Prior work on the Thatcher illusion (Cornes et al., 2011; Mestry et al., 2012) has indicated both perceptual and decisional components of the illusion. We provide evidence of neural correlates associated with independent influences of inversion and level of feature manipulation (Thatcherisation) in the Thatcher illusion. We also provide an account of how ERP results can be interpreted within the configural processing framework defined by general recognition theory (GRT). We conducted a study examining inversion and the level of Thatcherisation (typical face, eyes Thatcherised, mouth Thatcherised, or both features Thatcherised) on a set of event-related components (the P1, N170, P2 and P3b) that have previously been considered in relation to the Thatcher illusion. Results reveal three independent effects: (1) inversion effects leading to increased amplitude for inverted faces at the N170 and P2 in the occipito-parietal area; (2) a reduction in N170 amplitude with level of Thatcherisation in the right hemisphere; and (3) inversion effects leading to increased amplitude for inverted faces at P3b in the centro-parietal area. This study reveals effects of Thatcherisation that are independent from effects of inversion in the ERP data. These effects can also be mapped to perceptual and decisional measures of configurality revealed in behavioural data using GRT (Mestry et al., 2012). We suggest the Thatcherisation effect at N170 may relate to violations of perceptual independence, the inversion effect across N170 and P2 may relate to violations of perceptual separability, and the inversion effect at P3b may relate to violations of decisional separability. Thus, we suggest a possible role for ERP data in providing a source of converging evidence for inferences regarding the role of perceptual and decisional factors in configurality.

A Practical Way to Estimate Retail Tobacco Sales Violation Rates More Accurately

U.S. states annually estimate retailer propensity to sell adolescents cigarettes, which is a violation of law, by staging a single purchase attempt among a random sample of tobacco businesses. The accuracy of single-visit estimates is unknown. We examined this question using a novel test-retest protocol. Supervised minors attempted to purchase cigarettes at all retail tobacco businesses located in 3 Colorado counties. The attempts observed federal standards: Minors were aged 15-16 years, were nonsmokers, and were free of visible tattoos and piercings, and were allowed to enter stores alone or in pairs to purchase a small item while asking for cigarettes and to show or not show genuine identification (ID, e.g., driver's license). Unlike federal standards, stores received a second purchase attempt within a few days unless minors were firmly told not to return. Separate violation rates were calculated for first visits, second visits, and either visit. Eleven minors attempted to purchase cigarettes 1,079 times from 671 retail businesses. One sixth of first visits (16.8%) resulted in a violation; the rate was similar for second visits (15.7%). Considering either visit, 25.3% of businesses failed the test. Factors predictive of violation were whether clerks asked for ID, whether the clerks closely examined IDs, and whether minors included snacks or soft drinks in cigarette purchase attempts. A test-retest protocol for estimating underage cigarette sales detected half again as many businesses in violation as the federally approved one-test protocol. Federal policy makers should consider using the test-retest protocol to increase accuracy and awareness of widespread adolescent access to cigarettes through retail businesses.

An approach to optimization of airport taxiway scheduling and traversal under uncertainty

Airport runways and taxiways have been identified as a key source of system-wide congestion and delay in the over-strained commercial air traffic system. To combat this growing problem, we present a novel approach for taxiway scheduling and traversal. Aircraft must traverse a taxiway, represented by a graph, from gates to their respective runways and arrive at their scheduled times while adhering to safety separation constraints. We describe a combinatorial mixed-integer linear program to determine the push-back time windows, aircraft speeds, stopping times, and in particular, traversal paths for a given graph and an imposed flight schedule as part of a single optimization problem. Safety and scheduling constraints are made robust to probabilistic deviations from the prescribed schedule and aircraft motion, and multiple objective functions are considered to examine the trade-off between taxi times and the probability of safety separation violation. Several scenarios are presented to demonstrate improvements gained from the method and possible uses for this approach.

Identifying Sources of Configurality in Three Face Processing Tasks

Participants performed three feature-complete face processing tasks involving detection of changes in: (1) feature size and (2) feature identity in successive matching tasks, and (3) feature orientation. In each experiment, information in the top (eyes) and bottom (mouths) parts of faces were manipulated. All tasks were performed with upright and inverted faces. Data were analyzed first using group-based analysis of signal detection measures (sensitivity and bias), and second using analysis of multidimensional measures of sensitivity and bias along with probit regression models in order to draw inferences about independence and separability as defined within general recognition theory (Ashby and Townsend, 1986). The results highlighted different patterns of perceptual and decisional influences across tasks and orientations. There was evidence of orientation specific configural effects (violations of perceptual independence, perceptual seperability and decisional separabilty) in the Feature Orientation Task. For the Feature Identity Task there were orientation specific performance effects and there was evidence of configural effects (violations of decisional separability) in both orientations. Decisional effects are consistent with previous research (Wenger and Ingvalson, 2002, 2003; Richler et al., 2008; Cornes et al., 2011). Crucially, the probit analysis revealed violations of perceptual independence that remain undetected by marginal analysis.

The Erotics of Amplification in the Pamphilus de Amore

The Pamphilus de Amore, a twelfth-century comedy that recounts the seduction and rape of the virgin Galathea by the youth Pamphilus, has generated a critical controversy about whether Galathea is sincere in her protests of the rape. The Pamphilus exacerbates the difficulty of distinguishing between love from afar and sexual coercion, I argue, by exploiting the concealment inherent to the rhetorical techniques of circumvention and periphrasis. I show that Galathea does indeed try to separate violation from sex, an effort flagged most clearly when she tries to break from the text’s stylistic investment in circumlocution. If this implies that Galathea wants to call attention to the difference between sex and rape, it is also the case that her request is refused, by Pamphilus, by the Old Woman who acts as his pander, and by the text itself. In the end it is sexualized violence, rather than sex itself, that is the unnarratable center of the Pamphilus.

Individual Differences in the Effect of Vertical Separation on Conflict Detection in Air Traffic Control

This research examined individual differences in judgments of the risk of aircraft separation violation. Fourteen controllers were asked to judge the risk of conflict for aircraft pairs varying in geometry and vertical separation. A cluster analysis revealed individual differences in how judgments of conflict risk changed with increased vertical separation. There were no individual differences in conflict risk judgments when vertical separation was 0 ft. However, as vertical separation increased to 2,000 ft and 4,000 ft, some controllers made progressively lower judgments of conflict risk than others. These findings have implications for the design of automation tools and for training.

Numerical Renormalization Group at Marginal Spectral Density: Application to Tunneling in Luttinger Liquids

Many quantum mechanical problems (such as dissipative phase fluctuations in metallic and superconducting nanocircuits or impurity scattering in Luttinger liquids) involve a continuum of bosonic modes with a marginal spectral density diverging as the inverse of energy. We construct a numerical renormalization group in this singular case, with a manageable violation of scale separation at high energy, capturing reliably the low energy physics. The method is demonstrated by a nonperturbative solution over several energy decades for the dynamical conductance of a Luttinger liquid with a single static defect.

Perceptual and decisional factors influencing the discrimination of inversion in the Thatcher illusion.

The Thatcher illusion (Thompson, 1980) is considered to be a prototypical illustration of the notion that face perception is dependent on configural processes and representations. We explored this idea by examining the relative contributions of perceptual and decisional processes to the ability of observers to identify the orientation of two classes of forms-faces and churches-and a set of their component features. Observers were presented with upright and inverted images of faces and churches in which the components (eyes, mouth, windows, doors) were presented either upright or inverted. Observers first rated the subjective grotesqueness of all of the images and then performed a complete identification task in which they had to identify the orientation of the overall form and the orientation of each of the interior features. Grotesqueness ratings for both classes of image showed the standard modulation of rated grotesqueness as a function of orientation. The complete identification results revealed violations of both perceptual and decisional separability but failed to reveal any violations of within-stimulus (perceptual) independence. In addition, exploration of a simple bivariate Gaussian signal detection model of the relationship between identification performance and judged grotesqueness suggests that within-stimulus violations of perceptual independence on their own are insufficient for producing the illusion. This lack of evidence for within-stimulus configurality suggests the need for a critical reevaluation of the role of configural processing in the Thatcher illusion. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

Indecision on decisional separability

The theoretical framework of General Recognition Theory (GRT; Ashby & Townsend, Psychological Review, 93, 154-179, 1986) coupled with the empirical analysis tools of Multidimensional Signal Detection Analysis (MSDA; Kadlec & Townsend, Multidimensional models of perception and recognition, pp. 181-228, 1992) have become one important method for assessing dimensional interactions in perceptual decision-making. In this article, we critically examine MSDA and characterize cases where it is unable to discriminate two kinds of dimensional interactions: perceptual separability and decisional separability. We performed simulations with known instances of violations of perceptual or decisional separability, applied MSDA to the data generated by these simulations, and evaluated MSDA on its ability to accurately characterize the perceptual versus decisional source of these simulated dimensional interactions. Critical cases of violations of perceptual separability are often mischaracterized by MSDA as violations of decisional separability.

Rating Severity of Aircraft Separation Violations from Logic of Relative Collision Probability in Event Reenactment

Rating the severity of losses of standard separation between aircraft in controlled airspace is a critical practice by FAA safety analysts in the measurement of aviation safety performance. The current practice in use by FAA safety analysts of using three categories is simple, but precludes making comparisons from data aggregated across the full range of separations. The proposed model rectifies this shortcoming by providing an approach to rating severity based on a relative collision probability estimate for an event that is replayed with quantitative separation variability based on published estimates. The model incorporates: (1) consideration of event reenactment of given horizontal and vertical separation with specified variability in each dimension, (2) probability density of co-location of the two aircraft to account for the overlap in aircraft variability for the event reenactment (formally the convolution or aggregation of co-location densities), and (3) size of each aircraft involved in horizontal and vertical dimensions. An appendix compares empirical measures of relative severity with those of the model. The form of such a model may be used to evaluate anticipated future changes in surveillance technology, separation standards, aircraft equipage, flight procedures, etc.