Search results for "Tightness"
showing 8 items of 8 documents
On some parameters related to weak noncompactness in L1(μ,E)
2009
A weak measure of noncompactness γU is defined in a Banach space in terms of convex compactness. We obtain relationships between the measure γU(A) of a bounded set A in the Bochner space L1(μ,E) and two parameters Π(A) and Λ1(A).
Free sequences and the tightness of pseudoradial spaces
2019
Let F(X) be the supremum of cardinalities of free sequences in X. We prove that the radial character of every Lindelof Hausdorff almost radial space X and the set-tightness of every Lindelof Hausdorff space are always bounded above by F(X). We then improve a result of Dow, Juhasz, Soukup, Szentmiklossy and Weiss by proving that if X is a Lindelof Hausdorff space, and $$X_\delta $$ denotes the $$G_\delta $$ topology on X then $$t(X_\delta ) \le 2^{t(X)}$$ . Finally, we exploit this to prove that if X is a Lindelof Hausdorff pseudoradial space then $$F(X_\delta ) \le 2^{F(X)}$$ .
Comparing deep‐end confinement in England & Wales and Norway
2022
Extreme forms of custody represent the boundary points of state power. The configuration of the most restrictive corners of prison systems, and what goes on within them, is highly instructive in exposing the objectives, limits, and implications of state coercion at its most severe. Based on data collected in England & Wales and Norway, this article has two main aims. The first is to explore the degree to which “deep-end” confinement differs between jurisdictions with different penal philosophies. The second is to understand how the most extreme form of confinement in each jurisdiction differs from the more typical carceral experiences within each system and its overall penal ethos. Empirica…
Differences between tight and loose cultures: a 33-nation study.
2011
With data from 33 nations, we illustrate the differences between cultures that are tight (have many strong norms and a low tolerance of deviant behavior) versus loose (have weak social norms and a high tolerance of deviant behavior). Tightness-looseness is part of a complex, loosely integrated multilevel system that comprises distal ecological and historical threats (e.g., high population density, resource scarcity, a history of territorial conflict, and disease and environmental threats), broad versus narrow socialization in societal institutions (e.g., autocracy, media regulations), the strength of everyday recurring situations, and micro-level psychological affordances (e.g., prevention …
Upper bounds for the tightness of the $$G_\delta $$-topology
2021
We prove that if X is a regular space with no uncountable free sequences, then the tightness of its $$G_\delta $$ topology is at most the continuum and if X is, in addition, assumed to be Lindelof then its $$G_\delta $$ topology contains no free sequences of length larger then the continuum. We also show that, surprisingly, the higher cardinal generalization of our theorem does not hold, by constructing a regular space with no free sequences of length larger than $$\omega _1$$ , but whose $$G_\delta $$ topology can have arbitrarily large tightness.
Variations of selective separability II: Discrete sets and the influence of convergence and maximality
2012
A space $X$ is called selectively separable(R-separable) if for every sequence of dense subspaces $(D_n : n\in\omega)$ one can pick finite (respectively, one-point) subsets $F_n\subset D_n$ such that $\bigcup_{n\in\omega}F_n$ is dense in $X$. These properties are much stronger than separability, but are equivalent to it in the presence of certain convergence properties. For example, we show that every Hausdorff separable radial space is R-separable and note that neither separable sequential nor separable Whyburn spaces have to be selectively separable. A space is called \emph{d-separable} if it has a dense $\sigma$-discrete subspace. We call a space $X$ D-separable if for every sequence of …
Effects of Air Tightness Tests on Steel Thin-Wall Box Structures with Circular and Rectangular Cross Sections
2019
In this paper, the effects of air tightness tests on steel box structures with rectangular or circular cross sections typical of port cranes (legs, arms, and crosspieces) are analyzed. Legs and arms are generally made with elements with profiles having a square or rectangular cross section, while the diagonal struts are made with profiles having circular cross sections. To verify the air tightness of these elements, a necessary requirement to protect them from corrosion if they are not protected with other protection techniques, air tightness tests are performed. These tests, in the framework of durability tests, must be carried out while maintaining the structure elasticity well below the …
On some parameters related to weak noncompactness in L1(μ,E)
2009
A measure of weak noncompactness γU is defined in a Banach space X in terms of convex compactness. We obtain relationships between the measure γU(A) of a bounded set A in the Bochner space L1(μ,E) and two parameters Π(A) and Λ1(A) related, respectively, to uniform integrability and weak-tightness. The criterion for relative weak compactness in L1(μ,E) is recovered.