scholarly journals A New Variant of the Minimum-Weight Maximum-Cardinality Clique Problem to Solve Conflicts between Aircraft

2015 ◽  
pp. 3-14
Author(s):  
Thibault Lehouillier ◽  
Jérémy Omer ◽  
François Soumis ◽  
Guy Desaulniers
Keyword(s):  
Minimum Weight ◽  
Maximum Cardinality ◽  
New Variant ◽  
Clique Problem

Roman domination and 2-independence in trees

2017 ◽  
Vol 09 (02) ◽  
pp. 1750023 ◽  
Author(s):  
Nacéra Meddah ◽  
Mustapha Chellali
Keyword(s):  
Independence Number ◽  
Minimum Weight ◽  
Domination Number ◽  
Independent Set ◽  
Maximum Cardinality ◽  
Roman Domination ◽  
Roman Domination Number ◽  
Number Formula ◽  
Sum Formula ◽  
Roman Dominating Function

A Roman dominating function (RDF) on a graph [Formula: see text] is a function [Formula: see text] satisfying the condition that every vertex [Formula: see text] with [Formula: see text] is adjacent to at least one vertex [Formula: see text] of [Formula: see text] for which [Formula: see text]. The weight of a RDF is the sum [Formula: see text], and the minimum weight of a RDF [Formula: see text] is the Roman domination number [Formula: see text]. A subset [Formula: see text] of [Formula: see text] is a [Formula: see text]-independent set of [Formula: see text] if every vertex of [Formula: see text] has at most one neighbor in [Formula: see text] The maximum cardinality of a [Formula: see text]-independent set of [Formula: see text] is the [Formula: see text]-independence number [Formula: see text] Both parameters are incomparable in general, however, we show that if [Formula: see text] is a tree, then [Formula: see text]. Moreover, all extremal trees attaining equality are characterized.

scholarly journals Local Search for Minimum Weight Dominating Set with Two-Level Configuration Checking and Frequency Based Scoring Function (Extended Abstract)

2017 ◽  
Author(s):  
Yiyuan Wang ◽  
Shaowei Cai ◽  
Minghao Yin
Keyword(s):  
Local Search ◽  
Search Algorithm ◽  
Dominating Set ◽  
Minimum Weight ◽  
Scoring Function ◽  
Solution Quality ◽  
Configuration Checking ◽  
New Variant ◽  
New Ideas ◽  
Better Than

The Minimum Weight Dominating Set (MWDS) problem is an important generalization of the Minimum Dominating Set (MDS) problem with extensive applications. This paper proposes a new local search algorithm for the MWDS problem, which is based on two new ideas. The first idea is a heuristic called two-level configuration checking (CC2), which is a new variant of a recent powerful configuration checking strategy (CC) for effectively avoiding the recent search paths. The second idea is a novel scoring function based on the frequency of being uncovered of vertices. Our algorithm is called CC2FS, according to the names of the two ideas. The experimental results show that, CC2FS performs much better than some state-of-the-art algorithms in terms of solution quality on a broad range of MWDS benchmarks.

scholarly journals Local Search for Minimum Weight Dominating Set with Two-Level Configuration Checking and Frequency Based Scoring Function

2017 ◽  
Vol 58 ◽  
pp. 267-295 ◽  
Author(s):  
Yiyuan Wang ◽  
Shaowei Cai ◽  
Minghao Yin
Keyword(s):  
Local Search ◽  
Search Algorithm ◽  
Dominating Set ◽  
Minimum Weight ◽  
Scoring Function ◽  
Solution Quality ◽  
Configuration Checking ◽  
New Variant ◽  
New Ideas ◽  
Better Than

The Minimum Weight Dominating Set (MWDS) problem is an important generalization of the Minimum Dominating Set (MDS) problem with extensive applications. This paper proposes a new local search algorithm for the MWDS problem, which is based on two new ideas. The first idea is a heuristic called two-level configuration checking (CC2), which is a new variant of a recent powerful configuration checking strategy (CC) for effectively avoiding the recent search paths. The second idea is a novel scoring function based on the frequency of being uncovered of vertices. Our algorithm is called CC2FS, according to the names of the two ideas. The experimental results show that, CC2FS performs much better than some state-of-the-art algorithms in terms of solution quality on a broad range of MWDS benchmarks.

scholarly journals Minimum weight resolving sets of grid graphs

2016 ◽  
Vol 08 (03) ◽  
pp. 1650048
Author(s):  
Patrick Andersen ◽  
Cyriac Grigorious ◽  
Mirka Miller
Keyword(s):  
Shortest Path ◽  
Minimum Weight ◽  
Weighted Graph ◽  
Complete Characterization ◽  
Simple Graph ◽  
Resolving Set ◽  
Maximum Cardinality ◽  
Grid Graphs ◽  
Characterization Of Solutions

For a simple graph [Formula: see text] and for a pair of vertices [Formula: see text], we say that a vertex [Formula: see text] resolves [Formula: see text] and [Formula: see text] if the shortest path from [Formula: see text] to [Formula: see text] is of a different length than the shortest path from [Formula: see text] to [Formula: see text]. A set of vertices [Formula: see text] is a resolving set if for every pair of vertices [Formula: see text] and [Formula: see text] in [Formula: see text], there exists a vertex [Formula: see text] that resolves [Formula: see text] and [Formula: see text]. The minimum weight resolving set problem is to find a resolving set [Formula: see text] for a weighted graph [Formula: see text] such that [Formula: see text] is minimum, where [Formula: see text] is the weight of vertex [Formula: see text]. In this paper, we explore the possible solutions of this problem for grid graphs [Formula: see text] where [Formula: see text]. We give a complete characterization of solutions whose cardinalities are 2 or 3, and show that the maximum cardinality of a solution is [Formula: see text]. We show that the grid has the property that given a landmark set, we only need to investigate whether or not all pairs of vertices that share common neighbors are resolved to determine if the whole graph is resolved. We use this result to provide a characterization of a class of minimals whose cardinalities range from [Formula: see text] to [Formula: see text] and show that the number of such minimals is [Formula: see text].

scholarly journals A BRKGA-based matheuristic for the maximum quasi-clique problem with an exact local search strategy

2020 ◽  
Author(s):  
Bruno Q. Pinto ◽  
Celso C Ribeiro ◽  
Jose-Angel Riveaux ◽  
Isabel Rosseti
Keyword(s):  
Data Mining ◽  
Genetic Algorithm ◽  
Local Search ◽  
Search Strategy ◽  
Phone Call ◽  
Computational Results ◽  
Maximum Cardinality ◽  
Call Graphs ◽  
Local Search Strategy ◽  
Clique Problem

Given a graph $G=(V,E)$ and a threshold $\gamma \in (0,1]$, the maximum cardinality quasi-clique problem consists in finding a maximum cardinality subset $C^*$ of the vertices in $V$ such that the density of the graph induced in $G$ by $C^*$ is greater than or equal to the threshold $\gamma$. This problem has a number of applications in data mining, e.g. in social networks or phone call graphs. We propose a matheuristic for solving the maximum cardinality quasi-clique problem, based on the hybridization of a biased random-key genetic algorithm (BRKGA) with an exact local search strategy. The newly proposed approach is compared with a pure biased random-key genetic algorithm, which was the best heuristic in the literature at the time of writing. Computational results show that the hybrid BRKGA outperforms the pure BRKGA.

scholarly journals On the Approximability of the Minimum Weight $t$-partite Clique Problem

2020 ◽  
Vol 24 (3) ◽  
pp. 171-190
Author(s):  
Geoffrey Solano ◽  
Guillaume Blin ◽  
Mathieu Raffinot ◽  
Jhoirene Clemente ◽  
Jaime Caro
Keyword(s):  
Minimum Weight ◽  
Clique Problem

Estimating the Valence of Single Stimuli: A New Variant of the Affective Simon Task

2003 ◽  
Vol 50 (2) ◽  
pp. 86-96 ◽  
Author(s):  
Andreas Voß ◽  
Klaus Rothermund ◽  
Dirk Wentura
Keyword(s):  
Simon Task ◽  
Emotional Expressions ◽  
Evaluation Task ◽  
New Variant ◽  
Game Context

Abstract. In this article, a modified variant of the Affective Simon Task (AST; De Houwer & Eelen, 1998 ) is presented as a measure of implicit evaluations of single stimuli. In the AST, the words “good” or “bad” have to be given as responses depending on the color of the stimuli. The AST was combined with an evaluation task to increase the salience of the valence of the presented stimuli. Experiment 1 investigated evaluations of schematic faces showing emotional expressions. In Experiment 2 we measured the valence of artificial stimuli that acquired valence in a game context during the experiment. Both experiments confirm the validity of the modified AST. The results also revealed a dissociation between explicit and implicit evaluations.

Further Studies on the Mechanisms for the Antithrombotic Effects of Sulfated Polysaccharides in Rabbits

1988 ◽  
Vol 60 (02) ◽  
pp. 188-192 ◽  
Author(s):  
F A Ofosu ◽  
F Fernandez ◽  
N Anvari ◽  
C Caranobe ◽  
F Dol ◽  
...  
Keyword(s):  
Antithrombin Iii ◽  
Ex Vivo ◽  
Thrombus Formation ◽  
Minimum Weight ◽  
Sulfated Polysaccharides ◽  
Pentosan Polysulfate ◽  
Heparin Cofactor Ii ◽  
Thrombin Inhibition ◽  
The Relationship ◽  
Prothrombin Activation

SummaryA recent study (Fernandez et al., Thromb. Haemostas. 1987; 57: 286-93) demonstrated that when rabbits were injected with the minimum weight of a variety of glycosaminoglycans required to inhibit tissue factor-induced thrombus formation by —80%, exogenous thrombin was inactivated —twice as fast in the post-treatment plasmas as the pre-treatment plasmas. In this study, we investigated the relationship between inhibition of thrombus formation and the extent of thrombin inhibition ex vivo. We also investigated the relationship between inhibition of thrombus formation and inhibition of prothrombin activation ex vivo. Four sulfated polysaccharides (SPS) which influence coagulation in a variety of ways were used in this study. Unfractionated heparin and the fraction of heparin with high affinity to antithrombin III potentiate the antiproteinase activity of antithrombin III. Pentosan polysulfate potentiates the activity of heparin cofactor II. At less than 10 pg/ml of plasma, all three SPS also inhibit intrinsic prothrombin activation. The fourth agent, dermatan sulfate, potentiates the activity of heparin cofactor II but fails to inhibit intrinsic prothrombin activation even at concentrations which exceed 60 pg/ml of plasma. Inhibition of thrombus formation by each sulfated polysaccharides was linearly related to the extent of thrombin inhibition achieved ex vivo. These observations confirm the utility of catalysis of thrombin inhibition as an index for assessing antithrombotic potential of glycosaminoglycans and other sulfated polysaccharides in rabbits. With the exception of pentosan polysulfate, there was no clear relationship between inhibition of thrombus formation and inhibition of prothrombin activation ex vivo.

The Economic Theory of the Firm: A Generalization

2012 ◽  
pp. 41-66 ◽  
Author(s):  
M. Storchevoy
Keyword(s):  
Economic Theory ◽  
General Theory ◽  
Contract Theory ◽  
Theory Of The Firm ◽  
Material Structure ◽  
Structural Factors ◽  
Boundaries Of The Firm ◽  
Opportunistic Behaviour ◽  
New Variant

The paper deals with development of a general theory of the firm. It discusses the demand for such a theory, reviews existing approaches to its generalization, and offers a new variant of general theory of the firm based on the contract theory. The theory is based on minimization of opportunistic behaviour determined by the material structure of production (a classification of ten structural factors is offered). This framework is applied to the analysis of three boundaries problems (boundaries of the job, boundaries of the unit, boundaries of the firm) and five integration dilemmas (vertical, horizontal, functional, related, and conglomerate).

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