scholarly journals Visibility reasoning for concurrent snapshot algorithms

2022 ◽  
Vol 6 (POPL) ◽  
pp. 1-30
Author(s):  
Joakim Öhman ◽  
Aleksandar Nanevski
Keyword(s):  
Interface Properties ◽  
Level Of Abstraction ◽  
Concurrent Algorithms ◽  
Abstraction Levels

Visibility relations have been proposed by Henzinger et al. as an abstraction for proving linearizability of concurrent algorithms that obtains modular and reusable proofs. This is in contrast to the customary approach based on exhibiting the algorithm's linearization points. In this paper we apply visibility relations to develop modular proofs for three elegant concurrent snapshot algorithms of Jayanti. The proofs are divided by signatures into components of increasing level of abstraction; the components at higher abstraction levels are shared, i.e., they apply to all three algorithms simultaneously. Importantly, the interface properties mathematically capture Jayanti's original intuitions that have previously been given only informally.

Abstraction As a Configuration Design Methodology

1993 ◽  
Author(s):  
Gary L. Snavely ◽  
Panos Y. Papalambros
Keyword(s):  
Design Methodology ◽  
Configuration Design ◽  
Levels Of Abstraction ◽  
Level Of Abstraction ◽  
Abstraction Levels

Abstract Configuration design can be thought of as a process of generating artifacts by assembling pre-defined components. This paper introduces a method for reducing the size of configuration problems by abstracting components to higher levels of abstraction. At higher abstraction levels, less important detail is temporarily ignored, and each component represents a family of lower-level components. Configuration is then performed at the highest level, explicitly enumerating all configurations at that level. Any complete configuration at the highest level is recursively instantiated to lower levels. At the same time, any incomplete configuration at the highest level is eliminated, thereby eliminating all possible lower-level instantiations of that configuration. In this manner, all configurations of components at the lowest level of abstraction are implicitly enumerated.

Initiating, Maintaining, or Breaking Up?

2014 ◽  
Vol 45 (5) ◽  
pp. 408-420 ◽  
Author(s):  
Michela Menegatti ◽  
Monica Rubini
Keyword(s):  
Romantic Relationships ◽  
Romantic Relationship ◽  
Self Disclosure ◽  
Level Of Abstraction ◽  
Problematic Relationship ◽  
Abstract Language ◽  
Language Abstraction

Two studies examined whether individuals vary the level of abstraction of messages composed to achieve the relational goals of initiating, maintaining, and ending a romantic relationships when the goal of communication was self-disclosure or persuading one’s partner. Study 1 showed that abstract language was preferred to disclose thoughts and feelings about initiating a romantic relationship or to persuade the partner to consolidate a long-term one. Study 2 revealed that participants used abstract terms to persuade the partner to continue a problematic relationship and to disclose their thoughts on ending it. These results show that language abstraction is a flexible means to handle individuals’ goals and influence the course of romantic relationships.

“Farewell to Unjustified Enrichment?” – A Common Law Response

2016 ◽  
Vol 20 (3) ◽  
pp. 326-337
Author(s):  
Steve Hedley
Keyword(s):  
Common Law ◽  
German Law ◽  
Unjust Enrichment ◽  
Level Of Abstraction ◽  
The Law ◽  
Unjustified Enrichment ◽  
High Level ◽  
Logical Process

In this article, Professor Steve Hedley offers a Common Law response to he recently published arguments of Professor Nils Jansen on the German law of unjustified enrichment (as to which, see Jansen, “Farewell to Unjustified Enrichment” (2016) 20 EdinLR 123). The author takes the view that Jansen's paper provided a welcome opportunity to reconsider not merely what unjust enrichment can logically be, but what it is for. He argues that unjust enrichment talk contributes little of value, and that the supposedly logical process of stating it at a high level of abstraction, and then seeking to deduce the law from that abstraction, merely distracts lawyers from the equities of the cases they consider.

A Tight Connection Among Wealth, Income, Sustainability, and Accounting in an Ultra-Simplified Setting

2017 ◽  
Author(s):  
Martin L. Weitzman
Keyword(s):  
Economic Theory ◽  
Quantitative Relationship ◽  
Theoretical Relationship ◽  
Level Of Abstraction ◽  
Tight Connection ◽  
Basic Concepts ◽  
High Level ◽  
Very High

In theory, and under some very strong assumptions, there exists a tight quantitative relationship among the following four fundamental economic concepts: (1) ‘wealth’; (2) ‘income’; (3) ‘sustainability’; (4) ‘accounting’. These four basic concepts are placed in quotation marks here because a necessary first step will be to carefully and rigorously define what exactly is meant by each. This chapter reviews what is known about this important fourfold quantitative relationship in an ultra-simplified setting. It identifies some basic applications of this simplified economic theory of wealth and income (and sustainability and accounting). While the contents of this chapter are expressed at a very high level of abstraction and require many restrictive assumptions, the fundamental fourfold relationship it sharply highlights should be useful for conceptualizing, at least in principle, what is ‘wealth’ and what is its theoretical relationship to ‘income’, ‘sustainability’, and ‘accounting’.

scholarly journals fenicsR13

2021 ◽  
Vol 47 (2) ◽  
pp. 1-29
Author(s):  
Lambert Theisen ◽  
Manuel Torrilhon
Keyword(s):  
Gas Flow ◽  
Differential Operators ◽  
Mixed Finite Element ◽  
Test Cases ◽  
Typical Application ◽  
Flow Models ◽  
Computing Platform ◽  
Abstraction Levels ◽  
Variational Formulations ◽  
Rarefaction Effects

We present a mixed finite element solver for the linearized regularized 13-moment equations of non-equilibrium gas dynamics. The Python implementation builds upon the software tools provided by the FEniCS computing platform. We describe a new tensorial approach utilizing the extension capabilities of FEniCS’ Unified Form Language to define required differential operators for tensors above second degree. The presented solver serves as an example for implementing tensorial variational formulations in FEniCS, for which the documentation and literature seem to be very sparse. Using the software abstraction levels provided by the Unified Form Language allows an almost one-to-one correspondence between the underlying mathematics and the resulting source code. Test cases support the correctness of the proposed method using validation with exact solutions. To justify the usage of extended gas flow models, we discuss typical application cases involving rarefaction effects. We provide the documented and validated solver publicly.

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