scholarly journals Circuit Covers of Signed Eulerian Graphs

10.37236/9084 ◽  
2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Bo Bao ◽  
Rong Chen ◽  
Genghua Fan
Keyword(s):  
Signed Graph ◽  
Natural Analog ◽  
Eulerian Graphs ◽  
Graphic Matroid

A signed circuit cover of a signed graph is a natural analog of a circuit cover of a graph, and is equivalent to a covering of its corresponding signed-graphic matroid with circuits. It was conjectured that a signed graph whose signed-graphic matroid has no coloops has a 6-cover. In this paper, we prove that the conjecture holds for signed Eulerian graphs.

Harary index of Eulerian graphs

2021 ◽  
Author(s):  
Junqing Cai ◽  
Panpan Wang ◽  
Linlin Zhang
Keyword(s):  
Harary Index ◽  
Eulerian Graphs

scholarly journals A note on a walk-based inequality for the index of a signed graph

2021 ◽  
Vol 9 (1) ◽  
pp. 19-21
Author(s):  
Zoran Stanić
Keyword(s):  
Adjacency Matrix ◽  
Signed Graph ◽  
Arbitrary Length ◽  
Largest Eigenvalue ◽  
The Largest Eigenvalue

Abstract We derive an inequality that includes the largest eigenvalue of the adjacency matrix and walks of an arbitrary length of a signed graph. We also consider certain particular cases.

Bipartite output regulation for singular heterogeneous multi‐agent systems on signed graph

2021 ◽  
Author(s):  
Jie Wu ◽  
Qun Deng ◽  
Tao Han ◽  
Huai‐Cheng Yan
Keyword(s):  
Output Regulation ◽  
Signed Graph ◽  
Multi Agent Systems ◽  
Agent Systems ◽  
Multi Agent

scholarly journals Relation Representation Learning Via Signed Graph Mutual Information Maximization for Trust Prediction

Symmetry ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 115
Author(s):  
Yongjun Jing ◽  
Hao Wang ◽  
Kun Shao ◽  
Xing Huo
Keyword(s):  
Mutual Information ◽  
Representation Learning ◽  
Signed Graph ◽  
Trust Prediction ◽  
Trust Networks ◽  
Trust Relation ◽  
Information Maximization ◽  
Real World Datasets ◽  
Negative Links ◽  
Mutual Information Maximization

Trust prediction is essential to enhancing reliability and reducing risk from the unreliable node, especially for online applications in open network environments. An essential fact in trust prediction is to measure the relation of both the interacting entities accurately. However, most of the existing methods infer the trust relation between interacting entities usually rely on modeling the similarity between nodes on a graph and ignore semantic relation and the influence of negative links (e.g., distrust relation). In this paper, we proposed a relation representation learning via signed graph mutual information maximization (called SGMIM). In SGMIM, we incorporate a translation model and positive point-wise mutual information to enhance the relation representations and adopt Mutual Information Maximization to align the entity and relation semantic spaces. Moreover, we further develop a sign prediction model for making accurate trust predictions. We conduct link sign prediction in trust networks based on learned the relation representation. Extensive experimental results in four real-world datasets on trust prediction task show that SGMIM significantly outperforms state-of-the-art baseline methods.

Eigenvalues and chromatic number of a signed graph

2021 ◽  
Author(s):  
Wei Wang ◽  
Zhidan Yan ◽  
Jianguo Qian
Keyword(s):  
Chromatic Number ◽  
Signed Graph

scholarly journals A signed network perspective on the government formation process in parliamentary democracies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Angela Fontan ◽  
Claudio Altafini
Keyword(s):  
Decision Making ◽  
Formation Process ◽  
Signed Graph ◽  
Balance Theory ◽  
Collective Decision Making ◽  
Dynamical Models ◽  
Average Correlation ◽  
Parliamentary Democracies ◽  
Signed Network ◽  
The Government

AbstractIn parliamentary democracies, government negotiations talks following a general election can sometimes be a long and laborious process. In order to explain this phenomenon, in this paper we use structural balance theory to represent a multiparty parliament as a signed network, with edge signs representing alliances and rivalries among parties. We show that the notion of frustration, which quantifies the amount of “disorder” encoded in the signed graph, correlates very well with the duration of the government negotiation talks. For the 29 European countries considered in this study, the average correlation between frustration and government negotiation talks ranges between 0.42 and 0.69, depending on what information is included in the edges of the signed network. Dynamical models of collective decision-making over signed networks with varying frustration are proposed to explain this correlation.

Parallel algorithms for matroid intersection and matroid parity

2015 ◽  
Vol 07 (02) ◽  
pp. 1550019
Author(s):  
Jinyu Huang
Keyword(s):  
Parallel Algorithms ◽  
Polynomial Identity ◽  
Black Box ◽  
Matroid Intersection ◽  
Polynomial Identity Testing ◽  
Identity Testing ◽  
Common Base ◽  
Graphic Matroid ◽  
Matroid Parity ◽  
Nc Algorithms

A maximum linear matroid parity set is called a basic matroid parity set, if its size is the rank of the matroid. We show that determining the existence of a common base (basic matroid parity set) for linear matroid intersection (linear matroid parity) is in NC2, provided that there are polynomial number of common bases (basic matroid parity sets). For graphic matroids, we show that finding a common base for matroid intersection is in NC2, if the number of common bases is polynomial bounded. To our knowledge, these algorithms are the first deterministic NC algorithms for matroid intersection and matroid parity. We also give a new RNC2 algorithm that finds a common base for graphic matroid intersection. We prove that if there is a black-box NC algorithm for Polynomial Identity Testing (PIT), then there is an NC algorithm to determine the existence of a common base (basic matroid parity set) for linear matroid intersection (linear matroid parity).

Volcanic Glass as a Natural Analog for Borosilicate Waste Glass

1993 ◽  
Vol 333 ◽  
Author(s):  
Maury E. Morgenstein ◽  
Don L. Shettel
Keyword(s):  
Silica Glass ◽  
Glass Structure ◽  
Volcanic Glass ◽  
Waste Glass ◽  
Tensile Failure ◽  
Tensile Fracture ◽  
Failure Behavior ◽  
Basaltic Glass ◽  
Glass Waste ◽  
Natural Analog

ABSTRACTObsidian and basaltic glass are opposite end-members of natural volcanic glass compositions. Syngenetic and diagenetic tensile failure in basaltic glass (low silica glass) is pervasive and provides abundant alteration fronts deep into the glass structure. Perlitic fracturing in obsidian (high silica glass) limits the alteration zones to an “onion skin” geometry. Borosilicate waste glass behaves similarly to the natural analog of basaltic glass (sideromelane).During geologic time, established and tensile fracture networks form glass cells (a three-dimensional reticulated pattern) where the production of new fracture surfaces increases through time by geometric progression. This suggests that borosilicate glass monoliths will eventually become rubble. Rates of reaction appear to double for every 12C° of temperature increase. Published leach rates suggest that the entire inventory of certain radionuclides may be released during the 10,000 year regulatory time period. Steam alteration prior to liquid attack combined with pervasive deep tensile failure behavior may suggest that the glass waste form is not license defensible without a metallic- and/or ceramic-type composite barrier as an overpack.

Mechanisms for the Formation of a Perched Water Zone in Fractured Tuff: a Natural Analogue Study

1996 ◽  
Vol 465 ◽  
Author(s):  
E. G. Woodhouse ◽  
R. L. Bassett
Keyword(s):  
Structural Features ◽  
Yucca Mountain ◽  
Nuclear Waste Repository ◽  
Arid Environments ◽  
Perched Water ◽  
Natural Analog ◽  
Welded Tuff ◽  
Geochemical Properties ◽  
Water Zone ◽  
Mountain Site

ABSTRACTPerched water zones have been identified in the fractured, welded tuff in the semi-arid to arid environments of Yucca Mountain, Nevada and near Superior, Arizona. An understanding of the formation of such zones is necessary in order to predict where future perched water might form at Yucca Mountain, the proposed site of a high-level nuclear waste repository. The formation or growth of a perched zone near a repository is one of the factors to be considered in the risk assessment of the Yucca Mountain site.The Apache Leap Research Site near Superior, Arizona is a natural analog to the Yucca Mountain site in terms of geology, hydrology, and climate. Information used to study possible mechanisms for the formation of the perched zone included data regarding isotopie and geochemical properties of the waters in and above the perched water zone; measured hydrologie parameters of the perched zone; geophysical and measured parameters of the tuff; megascopic and microscopic observations of the tuff, including mineralogical, alteration, and structural features; and the lateral and vertical extent of perched water in the region.Aquifer test, geophysical, geochemical, and radioisotopic data show that fractures are the means by which water is recharging the perched zone. The reduced hydraulic conductivity of the formation in the perched zone appears to result from both a severe reduction in matrix porosity and permeability caused by welding, devitrification, and vapor phase crystallization; and by an increase in fracture filling which restricts the pathways for flow.

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