What Some Concepts Might Not Be

2020 ◽  
pp. 669-712
Author(s):  
Sharon Lee Armstrong ◽  
Lila R. Gleitman ◽  
Henry Gleitman
Keyword(s):  
Plane Geometry ◽  
Stimulus Materials

A discussion of the difficulties of prototype theories for describing compositional meaning motivates three experiments that inquire how well-defined concepts fare under paradigms that are commonly interpreted to support the prototype view. The stimulus materials include exemplars of prototype categories (sport, vehicle, fruit, vegetable) previously studied by others, and also exemplars of supposedly well-defined categories (odd number, even number, female and plane geometry figure)

Empathy Does Not Amplify Vicarious Threat Learning

2019 ◽  
Author(s):  
Alexander Lane Williams ◽  
Christopher C Conway
Keyword(s):  
Individual Differences ◽  
Skin Conductance ◽  
Defensive Response ◽  
Conditioned Stimuli ◽  
Defensive Reaction ◽  
Direct Exposure ◽  
Conditioned Responses ◽  
Clinically Significant ◽  
Stimulus Materials ◽  
Dispositional Empathy

Clinically significant fears and phobias can be acquired vicariously. Witnessing a demonstrator’s defensive reaction to potentially dangerous objects and situations can instill conditioned threat responses in the observer. The present study concentrates on individual differences in this social learning process. Specifically, we hypothesized that dispositional empathy modulates vicarious threat conditioning. We examined university students’ (N = 150) conditioned threat responding after they observed strangers undergo Pavlovian threat conditioning. There was evidence of a substantial conditioned defensive response (Cohen’s d = 0.66), as indexed by elevated skin conductance reactions during participants’ direct exposure to the vicariously conditioned stimuli. Contrary to expectations, indices of dispositional empathy were weakly related to the size of conditioned responses (median r = .04). Our results confirm that vicarious threat learning can be evaluated experimentally, but they do not support the hypothesis that empathy amplifies this process. The preregistration, stimulus materials, data, and analysis code for this study are available at https://osf.io/h6hm2.

Spacetime Geometry

2018 ◽  
Author(s):  
David M. Wittman
Keyword(s):  
Coordinate System ◽  
Special Relativity ◽  
Displacement Vector ◽  
Proper Time ◽  
Plane Geometry ◽  
Spatial Displacement ◽  
Spacetime Geometry ◽  
Space And Time ◽  
Displacement Vectors

This chapter shows that the counterintuitive aspects of special relativity are due to the geometry of spacetime. We begin by showing, in the familiar context of plane geometry, how a metric equation separates frame‐dependent quantities from invariant ones. The components of a displacement vector depend on the coordinate system you choose, but its magnitude (the distance between two points, which is more physically meaningful) is invariant. Similarly, space and time components of a spacetime displacement are frame‐dependent, but the magnitude (proper time) is invariant and more physically meaningful. In plane geometry displacements in both x and y contribute positively to the distance, but in spacetime geometry the spatial displacement contributes negatively to the proper time. This is the source of counterintuitive aspects of special relativity. We develop spacetime intuition by practicing with a graphic stretching‐triangle representation of spacetime displacement vectors.

Three-point perspective and plane geometry

2007 ◽  
Vol 1 (4) ◽  
pp. 213-223 ◽  
Author(s):  
Marc Frantz ◽  
Annalisa Crannell
Keyword(s):  
Plane Geometry

Static and dynamic response of sandwich beams with lattice and pantographic cores

2021 ◽  
pp. 109963622110338
Author(s):  
Yury Solyaev ◽  
Arseniy Babaytsev ◽  
Anastasia Ustenko ◽  
Andrey Ripetskiy ◽  
Alexander Volkov
Keyword(s):  
Mechanical Performance ◽  
Lattice Structure ◽  
Unit Length ◽  
Experimental Tests ◽  
Plane Geometry ◽  
Sandwich Beams ◽  
Static Tests ◽  
Three Point Bending ◽  
The Core ◽  
The Impact

Mechanical performance of 3d-printed polyamide sandwich beams with different type of the lattice cores is investigated. Four variants of the beams are considered, which differ in the type of connections between the elements in the lattice structure of the core. We consider the pantographic-type lattices formed by the two families of inclined beams placed with small offset and connected by stiff joints (variant 1), by hinges (variant 2) and made without joints (variant 3). The fourth type of the core has the standard plane geometry formed by the intersected beams lying in the same plane (variant 4). Experimental tests were performed for the localized indentation loading according to the three-point bending scheme with small span-to-thickness ratio. From the experiments we found that the plane geometry of variant 4 has the highest rigidity and the highest load bearing capacity in the static tests. However, other three variants of the pantographic-type cores (1–3) demonstrate the better performance under the impact loading. The impact strength of such structures are in 3.5–5 times higher than those one of variant 4 with almost the same mass per unit length. This result is validated by using numerical simulations and explained by the decrease of the stress concentration and the stress state triaxiality and also by the delocalization effects that arise in the pantographic-type cores.

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