EXPRESS: Using Relative-Speed-of-Processing to Explain the Shielding Function of Task Rules

In choice reaction tests, applying task rules instead of responding associatively can help participants shield against interference from distractors. However, the mechanism of such shielding functions remains unclear. Through four experiments, we show how the shielding function can be explained by the Relative-Speed-of-Processing theory. Experiment 1A demonstrated that applying task rules can reduce the relative processing advantage of the distractor by facilitating the target processing speed, thereby eliminating the interference effect. In Experiments 1B, and 1C, we manipulated the relative processing advantage between targets and distractors by adjusting the temporal sequence of the presence of the targets and distractors: stimuli appearing first would gain more relative processing advantage. The results showed that when the relative processing advantage of a distractor was large enough, applying task rules cannot help participants shield against the interference. Contrarily, when the relative processing advantage of the distractor was small, even without applying task rules, participants did not experience the interference. In Experiment 2, we directly manipulated the processing speed of the targets and the distractor, so that participants who responded associatively would facilitate target processing speed, but participants who applied task rules would not. Contrary to previous studies but in line with our prediction, in Experiment 2, only participants who applied task rules had interference effects. Our results suggested that applying the task rule might not help us shield against the interference directly. Instead, applying task rules improves target-processing speed, which in turn reduces the relative processing advantage of the distractor and eliminates the interference.

Strength Evaluation and Failure Analysis of the Vortex Reducer under Overspeed Condition

Rotating parts of aeroengines need to have a high speed margin according to the civil aviation airworthiness regulations. Previous studies on burst speed are based on mechanical properties of standard specimens. In this paper, a new method for predicting burst speed by means of a tensile test of a simulative specimen is proposed, and the predicted results are compared with the traditional method. The results show that the stress gradient of the designed simulative specimen and the assessment location of vortex reducer are in good agreement, which indicates that they have similar stress characteristics. The burst speed predicted by the new method is greater than the traditional method. Both prediction methods can provide a reference for such a structure in the design stage. In addition, the overspeed test of a vortex reducer is carried out, and the results verify that it still has sufficient strength reserves at 120% relative speed.

Bargaining under the Illusion of Transparency

This paper studies bargaining with noncommon priors where the buyer projects and exaggerates the probability that her private information may leak to the seller. Letting the buyer name her price first, raises the seller’s payoff above his payoff from posting a price. In seller-offer bargaining, projection implies a partial reversal of classic Coasian comparative static results. Weakening price commitment can benefit the seller and, as long as the relative speed at which imaginary information versus offers arrive does not converge to zero too quickly, frictionless bargaining converges to a fast haggling process which allows the seller to extract all surplus from trade. Bargaining under common prior transparency is instead slow and becomes equivalent to simply waiting. The comparative static predictions are consistent with experimental evidence. (JEL C78, D82)

Pacing and Body Weight Changes During a Mountain Ultramarathon: Sex Differences and Performance

The study was aimed at comparing pacing adopted by males and females in a 107-km mountain ultramarathon and assessing whether pacing-related variables were associated with intracompetition body weight changes and performance. Forty-seven athletes (29 males; 18 females) were submitted to a cardiopulmonary exercise test before the race. Athletes were also weighted before the start of the race, at three midpoints (33 km, 66 km and 84 km) and after the race. Pacing was analyzed using absolute and relative speeds and accelerometry-derived sedentary time spent during the race. Results showed that females spent less sedentary time (4.72 ± 2.91 vs. 2.62 ± 2.14%; p = 0.035; d = 0.83) and displayed a smaller body weight loss (3.01 ± 1.96 vs. 4.37 ± 1.77%; p = 0.048; d = 0.77) than males. No significant sex differences were revealed for speed variability, absolute and relative speed. In addition, finishing time was correlated with: speed variability (r = 0.45; p = 0.010), index of pacing (r = -0.63; p < 0.001) and sedentary time (r = 0.64; p < 0.001). Meanwhile, intracompetition body weight changes were related with both the absolute and relative speed in the first and the last race section. These results suggest that females, as compared with males, take advantage of shorter time breaks at aid stations. Moreover, performing a more even pacing pattern may be positively associated with performance in mountain ultramarathons. Finally, intracompetition body weight changes in those races should be considered in conjunction with running speed fluctuations.

Conditions for the appearance of stars with a rotation opposite to the orbital rotation of their planets

Обнаружение планетной системы K2-290 A с двумя копланарными планетами, которые обращаются в направлении, обратном вращению центральной звезды, ставит задачу поиска адекватного сценария возникновения таких систем. В данной статье представленные нами ранее сценарии образования планетных систем пересматриваются для оценки возможности формирования в их рамках планет с орбитальным вращением, обратным вращению их центральных звезд. Оценки показывают, что аккреция холодного газа гигантских молекулярных облаков старыми звездами солнечной массы, движущимися в этих облаках с низкой относительной скоростью менее ∼ 1 км/с - это наиболее вероятный сценарий возникновения таких планетных систем. С другой стороны, обратное вращение только одной из нескольких планет системы может быть результатом взаимодействия близких массивных планет на неустойчивых орбитах. Detection of planetary system K2-290 A with two coplanar planets, which rotate in the direction opposite to the rotation of the central star, poses the problem of finding an adequate scenario for the emergence of such systems. In this article, the scenarios for the formation of planetary systems are revised to assess the possibility of forming within their framework planets with orbital rotation opposite to the rotation of their central stars. Estimates show that the accretion of cold gas from giant molecular clouds (GMOs) by old solar-mass stars moving in GMOs with a relative speed less than ∼ 1 km/s - this is the most probable scenario for the emergence of such planetary systems. On the other hand, the opposite rotation of only one of the several planets of the system can be the result of interaction of nearby massive planets in unstable orbits.

Environmental variability and longevity predict the speed of the acute glucocorticoid response across birds.

The acute glucocorticoid response is a key mediator of the coordinated vertebrate response to unpredictable challenges. Rapid increases in glucocorticoids initiate a series of changes that can allow animals to effectively cope with or avoid stressors. It has become clear that the scope of the GC response-defined here as the absolute increase in GCs-is often associated with among-individual differences in performance and fitness and varies across species based on environment and life history. In addition to varying in scope, GC responses can differ enormously in speed; however, relatively little is known about whether speed and scope covary or how selection shapes variation in speed. We used a database of corticosterone samples collected at 5 time points from 1,750 individuals of 58 species of birds to ask i) how the speed and scope of the GC response covary among individuals and species and ii) whether variation among species in the speed of the response is predicted by environmental context or key life history traits. As predicted by a recent optimality model, faster absolute GC responses were strongly associated with a larger scope both among-individuals and among-species. Despite this covariation, the relative speed of the GC response (as a percentage of scope) varied independently of scope, suggesting that selection could operate on both features of the response independently. Species with faster relative GC responses lived in locations with more intra-season variation in temperature and had shorter lifespans. Our results suggest that rapid changes associated with the speed of the GC response, such as those occurring through non-genomic receptors, might be an important determinant of coping ability and we emphasize the need for studies explicitly designed to measure speed independently of scope.

Motion of a tightly fitting axisymmetric object through a lubricated elastic tube

We consider the translation of a rigid, axisymmetric, tightly fitting object through a cylindrical elastic tube filled with viscous fluid, using a combination of theory and direct numerical simulations. The intruding object is assumed to be wider than the undeformed tube radius, forcing solid–solid contact in the absence of relative motion. The motion of the object establishes a thin fluid film that lubricates this contact. Our theory couples lubrication theory to a geometrically nonlinear membrane description of the tube's elasticity, and applies to a slender intruding object and a thin tube with negligible bending rigidity. We show using asymptotic and numerical solutions of the theory, that the thickness of the thin fluid film scales with the square root of the relative speed for small speeds, set by a balance of hoop stresses, membrane tension and fluid pressure. While membrane tension is relatively small at the entrance of the film, it dominates near the exit and produces undulations of the film thickness, even in the limit of vanishing speeds and slender objects. We find that the drag force on the intruding object depends on the slope of its surface at the entrance to the thin fluid film, and scales as the square root of the relative speed. The predictions of the lubricated membrane theory for the shape of the film and the force on the intruder are in quantitative agreement with three-dimensional direct numerical simulations of the coupled fluid–elastic problem.

Calibrating Wiedemann-99 Model Parameters to Trajectory Data of Mixed Vehicular Traffic

We propose a new methodology for calibrating Wiedemann-99 vehicle-following parameters for mixed traffic (different conventional vehicle classes) based on trajectory data. The existing acceleration equations of the Wiedemann model are modified to represent more realistic driving behavior. Exploratory analysis of simulation data revealed that different Wiedemann-99 model parameters could lead to similar macroscopic behavior, highlighting the importance of calibration at the microscopic level. Therefore, the proposed methodology is based on optimizing performance measures at the microscopic level (acceleration, speed, and trajectory profiles) to estimate suitable calibration parameters. Further, the goodness of fit for the observed data is sensitive to the numerical integration method used to compute vehicles’ velocity and position. We found that the calibrated parameters using the proposed methodology perform better than other approaches for calibrating mixed traffic. The results reveal that the calibrated parameter values and, consequently, the thresholds that delineate closing, following, emergency braking, and opening regimes, vary between two-wheelers and cars. The window (in the relative speed versus gap plot) for the unconscious following is larger for cars while the free-flow regime is more extensive for two-wheelers. Moreover, under the same relative speed and gap stimulus, two-wheelers and cars may be in different regimes and display different acceleration responses. Thus, accurate calibration of each vehicle’s parameters is essential for developing micro-simulation models for mixed traffic. The calibration analysis results of strict and overlapping staggered car following signify an impact of staggered car following compared with strict car following which demands separate calibration for strict and staggered following.

Estimating Lane Change Duration for Overtaking in Nonlane-Based Driving Behavior by Local Linear Model Trees (LOLIMOT)

Lane change (LC) is one of the main maneuvers in traffic flow. Many studies have estimated LC duration directly by using lane-based data. The current research presents an estimate of LC duration for overtaking maneuver in nonlane-based traffic flow. In this paper, the LC duration is estimated implicitly by modeling lateral speed and applying the length of required lateral movement to complete the LC maneuver. In lateral speed modeling, the local linear model tree is applied which consists of three variables: the initial lateral distance, longitudinal speed, and time to collision (TTC), which itself is a function of the relative speed of follower and the distance between the two vehicles. The initial lateral distance is the relative transverse distance from which the following vehicle initializes the LC. The range of lateral speed was estimated between 0.5 and 5 km/h, which resulted in the LC duration between 2.5 and 24 sec. The results indicate that the lateral and longitudinal speed would be inversely related, while the lateral speed and the initial transverse distance as well as TTC would be directly related. The findings also indicate that TTC can be assumed as the most important factor affecting lateral speed. TTC at 8 sec can be considered as the threshold for its effect on the LC duration since at longer TTCs, and the lateral speed has remained almost constant. When TTC is longer than 8 sec, it would not affect the LC duration.

Centralized Algorithms Based on Clustering with Self-tuning of Parameters for Cooperative Target Observation

Clustering on target positions is a class of centralized algorithms used to calculate the surveillance robots' displacements in the Cooperative Target Observation (CTO) problem. This work proposes and evaluates Fuzzy C-means (FCM) and Density-Based Spatial Clustering of Applications with Noise (DBSCAN) with K-means (DBSk) based self-tuning clustering centralized algorithms for the CTO problem and compares its performances with that of K-means. Two random motion patterns are adopted for the targets: in free space or on a grid. As a contribution, the work allows identifying ranges of problem configuration parameters in which each algorithm shows the highest average performance. As a first conclusion, in the challenging situation in which the relative speed of the targets is high, and the relative sensor range of the surveillance is low, for which the existing algorithms present a substantial drop in performance, the FCM algorithm proposed outperforms the others. Finally, the DBSk algorithm adapts very well in low execution frequency, showing promising results in this challenging situation.