for Journals by Title or ISSN
for Articles by Keywords
help

Publisher: Elsevier   (Total: 3175 journals)

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

Showing 1 - 200 of 3175 Journals sorted alphabetically
A Practical Logic of Cognitive Systems     Full-text available via subscription   (Followers: 8)
AASRI Procedia     Open Access   (Followers: 14)
Academic Pediatrics     Hybrid Journal   (Followers: 28, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 22, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 90, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 25, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 33, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 5)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 6, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 376, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 27, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 2)
Acta de Investigación Psicológica     Open Access   (Followers: 3)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (Followers: 1, SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 235, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 10, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription  
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 2, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 1)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 25, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 3)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 2)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.383, h-index: 19)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 1)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 5, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 3, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 6)
Acute Pain     Full-text available via subscription   (Followers: 14)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.967, h-index: 57)
Addictive Behaviors     Hybrid Journal   (Followers: 15, SJR: 1.514, h-index: 92)
Addictive Behaviors Reports     Open Access   (Followers: 7)
Additive Manufacturing     Hybrid Journal   (Followers: 9, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 22)
Advanced Cement Based Materials     Full-text available via subscription   (Followers: 3)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 128, SJR: 5.2, h-index: 222)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.265, h-index: 53)
Advanced Powder Technology     Hybrid Journal   (Followers: 16, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 8, SJR: 0.299, h-index: 15)
Advances in Agronomy     Full-text available via subscription   (Followers: 12, SJR: 2.071, h-index: 82)
Advances in Anesthesia     Full-text available via subscription   (Followers: 27, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 10, SJR: 1.054, h-index: 35)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 10, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 22, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 14, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 2, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 28, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 7, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 2.139, h-index: 42)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 3)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 27, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 10, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 28, SJR: 0.938, h-index: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 14, SJR: 0.223, h-index: 22)
Advances in Dermatology     Full-text available via subscription   (Followers: 14)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 10)
Advances in Digestive Medicine     Open Access   (Followers: 8)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 21)
Advances in Ecological Research     Full-text available via subscription   (Followers: 42, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 27, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 6)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 42, SJR: 5.465, h-index: 64)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 1)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 7)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 54, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Genetics     Full-text available via subscription   (Followers: 14, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 7)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 2.325, h-index: 20)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 23)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 1, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 36, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 2, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 3)
Advances in Life Course Research     Hybrid Journal   (Followers: 8, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Marine Biology     Full-text available via subscription   (Followers: 14, SJR: 1.645, h-index: 45)
Advances in Mathematics     Full-text available via subscription   (Followers: 10, SJR: 3.261, h-index: 65)
Advances in Medical Sciences     Hybrid Journal   (Followers: 6, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 21)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 8)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, SJR: 0.324, h-index: 8)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 3)
Advances in Oncobiology     Full-text available via subscription   (Followers: 1)
Advances in Organ Biology     Full-text available via subscription   (Followers: 1)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15, SJR: 2.885, h-index: 45)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 6, SJR: 0.148, h-index: 11)
Advances in Parasitology     Full-text available via subscription   (Followers: 5, SJR: 2.37, h-index: 73)
Advances in Pediatrics     Full-text available via subscription   (Followers: 24, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 10)
Advances in Pharmacology     Full-text available via subscription   (Followers: 15, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 7)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 18, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 59)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6, SJR: 0.478, h-index: 32)
Advances in Radiation Oncology     Open Access  
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.1, h-index: 2)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 5)
Advances in Space Research     Full-text available via subscription   (Followers: 375, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 5)
Advances in Surgery     Full-text available via subscription   (Followers: 9, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 29, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 17)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 46, SJR: 2.408, h-index: 94)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 0.973, h-index: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 333, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 6, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 9, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 429, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 43, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access   (Followers: 1)
Agriculture and Natural Resources     Open Access   (Followers: 2)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 56, SJR: 1.879, h-index: 120)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.434, h-index: 14)
Air Medical J.     Hybrid Journal   (Followers: 5, SJR: 0.234, h-index: 18)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.285, h-index: 3)
Alcohol     Hybrid Journal   (Followers: 11, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 9)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access   (Followers: 1)
Algal Research     Partially Free   (Followers: 9, SJR: 2.05, h-index: 20)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.46, h-index: 29)
Allergology Intl.     Open Access   (Followers: 5, SJR: 0.776, h-index: 35)
Alpha Omegan     Full-text available via subscription   (SJR: 0.121, h-index: 9)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 9, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 48, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 4)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 6)
American Heart J.     Hybrid Journal   (Followers: 50, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 50, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 42, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 10, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 31, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 26, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 32, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 42, SJR: 2.023, h-index: 189)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 189, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 62, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 6)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 25, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 27, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 27, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 36, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 6)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 61, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 14)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 4, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 39, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 164, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 10, SJR: 0.18, h-index: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 11)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 1)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 22, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access   (Followers: 1)

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

Journal Cover AKCE International Journal of Graphs and Combinatorics
  [SJR: 0.285]   [H-I: 3]   [0 followers]  Follow
    
  This is an Open Access Journal Open Access journal
   ISSN (Print) 0972-8600
   Published by Elsevier Homepage  [3175 journals]
  • The line completion number of hypercubes

    • Authors: S.A. Tapadia; B.N. Waphare
      Abstract: Publication date: Available online 21 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): S.A. Tapadia, B.N. Waphare
      In 1992, Bagga, Beineke, and Varma introduced the concept of the super line graph of index r of a graph G , denoted by ℒ r ( G ) . The vertices of ℒ r ( G ) are the r -subsets of E ( G ) , and two vertices S and T are adjacent if there exist s ∈ S and t ∈ T such that s and t are adjacent edges in G . They also defined the line completion number l c ( G ) of graph G to be the minimum index r for which ℒ r ( G ) is complete. They found the line completion number for certain classes of graphs. In this paper, we find the line completion number of hypercube Q n for every n .

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.02.003
       
  • Trees with distinguishing number two

    • Authors: Saeid Alikhani; Samaneh Soltani
      Abstract: Publication date: Available online 21 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Saeid Alikhani, Samaneh Soltani
      The distinguishing number D ( G ) of a graph G is the least integer d such that G has a vertex labeling with d labels that is preserved only by a trivial automorphism. In this paper we characterize all trees with radius at most three and distinguishing number two. Also we present a necessary condition for trees with distinguishing number two and radius more than three.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.02.001
       
  • On the global offensive alliance in unicycle graphs

    • Authors: Mohamed Bouzefrane; Saliha Ouatiki
      Abstract: Publication date: Available online 15 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Mohamed Bouzefrane, Saliha Ouatiki
      For a graph G = ( V , E ) , a set S ⊆ V is a dominating set if every vertex in V − S has at least a neighbor in S . A dominating set S is a global offensive alliance if for each vertex v in V − S at least half the vertices from the closed neighborhood of v are in S . The domination number γ ( G ) is the minimum cardinality of a dominating set of G , and the global offensive alliance number γ o ( G ) is the minimum cardinality of a global offensive alliance of G . We show that if G is a connected unicycle graph of order n with l ( G ) leaves and s ( G ) support vertices then γ o ( G ) ≥ n − l ( G ) + s ( G ) 3 . Moreover, we characterize all extremal unicycle graphs attaining this bound.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.001
       
  • P2▹H-super antimagic total labeling of comb product of graphs

    • Authors: Ika Hesti Agustin; R.M. Prihandini; Dafik
      Abstract: Publication date: Available online 13 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Ika Hesti Agustin, R.M. Prihandini, Dafik
      Let L and H be two simple, nontrivial and undirected graphs. Let o be a vertex of H , the comb product between L and H , denoted by L ▹ H , is a graph obtained by taking one copy of L and V ( L ) copies of H and grafting the i th copy of H at the vertex o to the i th vertex of L . By definition of comb product of two graphs, we can say that V ( L ▹ H ) = { ( a , v ) a ∈ V ( L ) , v ∈ V ( H ) } and ( a , v ) ( b , w ) ∈ E ( L ▹ H ) whenever a = b and v w ∈ E ( H ) , or a b ∈ E ( L ) and v = w = o . Let G = L ▹ H and P 2 ▹ H ⊆ G , the graph G is said to be an ( a , d ) - P 2 ▹ H -antimagic total graph if there exists a bijective function f : V ( G ) ∪ E ( G ) → { 1 , 2 , … , V ( G ) + E ( G ) } such that for all subgraphs isomorphic to P 2 ▹ H , the total P 2 ▹ H -weights W ( P 2 ▹ H ) = ∑ v ∈ V ( P 2 ▹ H ) f ( v ) + ∑
      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.008
       
  • Automorphism groups of graph covers and uniform subset graphs

    • Authors: N.B. Mumba; E. Mwambene
      Abstract: Publication date: Available online 13 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): N.B. Mumba, E. Mwambene
      Hofmeister considered the automorphism groups of antipodal graphs through the exploration of graph covers. In this note we extend the exploration of automorphism groups of distance preserving graph covers. We apply the technique of graph covers to determine the automorphism groups of uniform subset graphs Γ ( 2 k , k , k − 1 ) and Γ ( 2 k , k , 1 ) . The determination of automorphism groups answers a conjecture posed by Mark Ramras and Elizabeth Donovan. They conjectured that Aut ( Γ ( 2 k , k , k − 1 ) ) ≅ S 2 k × < T > , where T is the complementation map X ↦ T ( X ) = X c = { 1 , 2 , … , 2 k } ∖ X , and X is a k -subset of Ω = { 1 , 2 , … , 2 k } .

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.016
       
  • Zeroth-order general Randić index of cactus graphs

    • Authors: Hassan Ahmed; Akhlaq Ahmad Bhatti; Akbar Ali
      Abstract: Publication date: Available online 12 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Hassan Ahmed, Akhlaq Ahmad Bhatti, Akbar Ali
      A connected graph G is said to be cactus if no two cycles of G have any common edge. The present note is devoted to developing some extremal results for the zeroth-order general Randić index of cactus graphs and finding some sharp bounds on this index.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.006
       
  • On total edge irregularity strength of centralized uniform theta graphs

    • Authors: Riyan Wicaksana Putra; Yeni Susanti
      Abstract: Publication date: Available online 12 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Riyan Wicaksana Putra, Yeni Susanti
      Let G = ( V , E ) be a simple connected and undirected graph. Let f : V ∪ E → { 1 , 2 , … , k } be a total labeling of G . The weight of an edge u v is defined by w f ( u v ) = f ( u ) + f ( v ) + f ( u v ) . The labeling f is called an edge irregular total k -labeling if w f ( u v ) ≠ w f ( u ′ v ′ ) for any two distinct edges u v , u ′ v ′ . If G admits such a labeling, then the minimum k is called the total edge irregularity strength of G . In this paper we determine the total edge irregularity strength of centralized uniform theta graphs.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.02.002
       
  • On super (a,d)-Cn-antimagic total labeling of disjoint union of cycles

    • Authors: Faisal Susanto
      Abstract: Publication date: Available online 12 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Faisal Susanto
      Let H and G be finite simple graphs where every edge of G belongs to at least one subgraph that is isomorphic to H . An ( a , d ) - H -antimagic total labeling of a graph G is a bijection f : V ( G ) ∪ E ( G ) → { 1 , 2 , … , V ( G ) + E ( G ) } such that for all subgraphs H ′ isomorphic to H , the H -weights, w ( H ′ ) = ∑ v ∈ V ( H ′ ) f ( v ) + ∑ u v ∈ E ( H ′ ) f ( u v ) form an arithmetic progression { a , a + d , … , a + ( k − 1 ) d } where a > 0 , d ≥ 0 are two fixed integers and k is the number of subgraphs of G isomorphic to H . Moreover, if the vertex set V ( G ) receives the minimum possible labels { 1 , 2 , … , V ( G ) } , then f is called a super ( a , d ) - H -antimagic total labeling. In this paper we study super ( a , d ) - C n -antimagic total labeling of a disconnected graph, namely m C n .

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.017
       
  • Gap terminology and related combinatorial properties for AVL trees and
           Fibonacci-isomorphic trees

    • Authors: Mahdi Amani
      Abstract: Publication date: Available online 12 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Mahdi Amani
      We introduce gaps that are edges or external pointers in AVL trees such that the height difference between the subtrees rooted at their two endpoints is equal to 2. Using gaps we prove the Basic-Theorem that illustrates how the size of an AVL tree (and its subtrees) can be represented by a series of powers of 2 of the heights of the gaps, this theorem is the first such simple formula to characterize the number of nodes in an AVL tree. Then, we study the extreme case of AVL trees, the perfectly unbalanced AVL trees, by introducing Fibonacci-isomorphic trees that are isomorphic to Fibonacci trees of the same height and showing that they have the maximum number of gaps in AVL trees. Note that two ordered trees (such as AVL trees) are isomorphic iff there exists a one-to-one correspondence between their nodes that preserves not only adjacency relations in the trees, but also the roots. In the rest of the paper, we study combinatorial properties of Fibonacci-isomorphic trees.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.019
       
  • Domination in graphoidally covered graphs: Least-kernel graphoidal
           graphs-II

    • Authors: Purnima Gupta; Rajesh Singh
      Abstract: Publication date: Available online 3 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Purnima Gupta, Rajesh Singh
      Given a graph G = ( V , E ) , not necessarily finite, a graphoidal cover of G means a collection Ψ of non-trivial paths in G called Ψ -edges, which are not necessarily open (not necessarily finite), such that every vertex of G is an internal vertex of at most one path in Ψ and every edge of G is in exactly one path in Ψ . The set of all graphoidal covers of a graph G = ( V , E ) is denoted by G G and for a given Ψ ∈ G G the ordered pair ( G , Ψ ) is called a graphoidally covered graph. Two vertices u and v of G are Ψ -adjacent if they are the ends of an open Ψ -edge. A set D of vertices in ( G , Ψ ) is Ψ -independent if no two vertices in D are Ψ -adjacent and is said to be Ψ -dominating if every vertex of G is either in D or is Ψ -adjacent to a vertex in D ; G is γ Ψ ( G ) -definable ( γ i Ψ ( G ) -definable) if ( G , Ψ ) has a finite Ψ -dominating ( Ψ -independent Ψ -dominating) set. Clearly, if G is γ i Ψ ( G ) -definable, then G is γ Ψ ( G ) -definable and γ Ψ ( G )
      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.002
       
  • A generalization of magic and antimagic labelings of graphs

    • Authors: C. Meenakshi; KM. Kathiresan
      Abstract: Publication date: Available online 3 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): C. Meenakshi, KM. Kathiresan
      A k-magic labeling of a finite, simple graph with V ( G ) = p and E ( G ) = q , is a bijection from the set of edges into the integers { 1 , 2 , 3 , … , q } such that the vertex set V can be partitioned into k sets V 1 , V 2 , V 3 , … , V k , 1 ≤ k ≤ p , and each vertex in the set V i has the same vertex sum and any two distinct vertices in different sets have different vertex sum, where a vertex sum is the sum of the labels of all edges incident with that vertex. A graph is called k-magic if it has k -magic labeling, for some k , 1 ≤ k ≤ p . The study of k -magic labeling is interesting, since all magic graphs are 1-magic and all antimagic graphs are p -magic. In this paper, we discuss the k -magicness of the Complete bipartite graph K p , p , where 1 ≤ k ≤ 2 p .

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.014
       
  • Some properties of 2-absorbing primary ideals in lattices

    • Authors: Meenakshi P. Wasadikar; Karuna T. Gaikwad
      Abstract: Publication date: Available online 2 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Meenakshi P. Wasadikar, Karuna T. Gaikwad
      We introduce the concepts of a primary and a 2-absorbing primary ideal and the radical of an ideal in a lattice. We study some properties of these ideals. A characterization for the radical of an ideal to be a primary ideal is given. Also a characterization for an ideal I to be a 2-absorbing primary ideal is proved. Examples and counter examples are given wherever necessary.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.015
       
  • Rank-metric codes as ideals for subspace codes and their weight properties

    • Authors: Bryan S. Hernandez; Virgilio P. Sison
      Abstract: Publication date: Available online 2 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Bryan S. Hernandez, Virgilio P. Sison
      Let q = p r , p a prime, r a positive integer, and F q the Galois field with cardinality q and characteristic p . In this paper, we study some weight properties of rank-metric codes and subspace codes. The rank weight is not egalitarian nor homogeneous, and the rank weight distribution of M 2 ( F q ) is completely determined by the general linear group G L ( 2 , q ) . We consider subspace weight that is defined on subspace codes and examine their egalitarian property. We also present some examples of rank-metric codes endowed with the rank distance and Grassmannian codes endowed with the subspace distance. These codes were generated from left ideals of M 2 ( F p ) using idempotent elements of M 2 ( F p ) .

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.005
       
  • Generalized projections in Zn

    • Authors: A.S. Khairnar; B.N. Waphare
      Abstract: Publication date: Available online 1 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): A.S. Khairnar, B.N. Waphare
      We consider the ring Z n (integers modulo n ) with the partial order ‘ ≤ ’ given by ‘ a ≤ b if either a = b or a ≡ a b ( m o d n ) ’. In this paper, we obtain necessary and sufficient conditions for the poset ( Z n , ≤ ) to be a lattice.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.010
       
  • Eulerian Cycle Decomposition Conjecture for the line graph of complete
           graphs

    • Authors: R. Rajarajachozhan; R. Sampathkumar
      Abstract: Publication date: Available online 1 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): R. Rajarajachozhan, R. Sampathkumar
      The Eulerian Cycle Decomposition Conjecture, by Chartrand, Jordon and Zhang, states that if the minimum number of odd cycles in a cycle decomposition of an Eulerian graph G of size m is a , the maximum number of odd cycles in such a cycle decomposition is b and ℓ is an integer such that a ≤ ℓ ≤ b where ℓ and m are of the same parity, then there is a cycle decomposition of G with exactly ℓ odd cycles. This conjecture is verified for the line graph of the complete graph.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.012
       
  • Structure connectivity of hypercubes

    • Authors: S.A. Mane
      Abstract: Publication date: Available online 1 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): S.A. Mane
      The connectivity of a graph is an important measurement for the fault-tolerance of the network. To provide more accurate measures for the fault-tolerance of networks than the connectivity, some generalizations of connectivity have been introduced. Let H be a connected subgraph of a graph G . A set F of a connected subgraph of G is called a subgraph cut of G if G − F is either connected or trivial. If further, each member of F is isomorphic to H , then F is called an H -structure cut of G. The H -structure connectivity κ ( G ; H ) of G is the minimum cardinality of an H -structure cut of G . In this paper we determine κ ( Q n ; H ) or its upper bound where Q n is the n -dimensional hypercube with n ≥ 4 and H is either Q m with m ≤ n − 2 or even cycle C l with l ≤ 2 n .

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.009
       
  • Results on the Wiener profile

    • Authors: Morteza Faghani; Gyula O.H. Katona
      Abstract: Publication date: Available online 1 February 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Morteza Faghani, Gyula O.H. Katona


      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.003
       
  • Note on edge irregular reflexive labelings of graphs

    • Authors: Martin Bača; Muhammad Irfan; Joe Ryan; Andrea Semaničová-Feňovčíková; Dushyant Tanna
      Abstract: Publication date: Available online 20 January 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Martin Bača, Muhammad Irfan, Joe Ryan, Andrea Semaničová-Feňovčíková, Dushyant Tanna
      For a graph G , an edge labeling f e : E ( G ) → { 1 , 2 , … , k e } and a vertex labeling f v : V ( G ) → { 0 , 2 , 4 , … , 2 k v } are called total k -labeling, where k = max { k e , 2 k v } . The total k -labeling is called an edge irregular reflexive k -labeling of the graph G , if for every two different edges x y and x ′ y ′ of G , one has w t ( x y ) = f v ( x ) + f e ( x y ) + f v ( y ) ≠ w t ( x ′ y ′ ) = f v ( x ′ ) + f e ( x ′ y ′ ) + f v ( y ′ ) . The minimum k for which the graph G has an edge irregular reflexive k -labeling is called the reflexive edge strength of G . In this paper we determine the exact value of the reflexive edge strength for cycles, Cartesian product of two cycles and for join graphs of the path and cycle with 2 K 2 .

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2018.01.013
       
  • 3-total edge product cordial labeling of rhombic grid

    • Authors: Aisha Javed; Muhammad Kamran Jamil
      Abstract: Publication date: Available online 10 January 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Aisha Javed, Muhammad Kamran Jamil
      For a simple graph G = ( V ( G ) , E ( G ) ) , this paper deals with the existence of an edge labeling χ : E ( G ) → { 0 , 1 , … , k − 1 } , 2 ≤ k ≤ E ( G ) , which induces a vertex labeling χ ∗ : V ( G ) → { 0 , 1 , … , k − 1 } in such a way that for each vertex v , assigns the label χ ( e 1 ) ⋅ χ ( e 2 ) ⋅ ⋯ ⋅ χ ( e n ) ( ( mod k ) ) , where e 1 , e 2 , … , e n are the edges incident to the vertex v . The labeling χ is called a k -total edge product cordial labeling of G if ( e χ ( i ) + v χ ∗ ( i ) ) − ( e χ ( j ) + v χ ∗ ( j ) ) ≤ 1 for every i , j , 0 ≤ i < j ≤ k − 1 , where e χ ( i ) and v χ ∗ ( i ) are the number of edges and vertices with χ ( e ) = i and χ ∗ ( e ) = i , respectively. In this paper, we examine the existence of such labeling for rhombic grid graph.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2017.12.002
       
  • Center of intersection graph of submodules of a module

    • Authors: Kukil Kalpa Rajkhowa; Helen K. Saikia
      Abstract: Publication date: Available online 5 January 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Kukil Kalpa Rajkhowa, Helen K. Saikia
      Let R be a commutative ring and M be a unital R -module. The intersection graph of submodules of M , denoted by G M , is the graph whose vertex set is the collection of all submodules of M and in which two distinct vertices A and B are adjacent if and only if A ∩ B ≠ 0 . In this paper the notion of essentiality of modules plays a vital role in the study of intersection graph of submodules of M . This notion gives a new dimension in characterizing the center of intersection graphs of submodules of M . We define mna (maximal non-adjacent) vertex in G M and observe some of its characteristics. The notion of complemented intersection graph exhibits some significant algebraic and graphical properties. Moreover, defining the concept of isolated center in G M we establish certain results related to mna vertex.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2017.12.004
       
  • Effect of vertex deletion on the weak Roman domination number of a graph

    • Authors: P. Roushini Leely Pushpam; M. Kamalam
      Abstract: Publication date: Available online 5 January 2018
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): P. Roushini Leely Pushpam, M. Kamalam
      Let G = ( V , E ) be a graph and f : V → { 0 , 1 , 2 } be a function. The weight of a vertex u ∈ V is f ( u ) and a vertex u with weight f ( u ) = 0 is said to be undefended with respect to f , if it is not adjacent to a vertex with positive weight. The function f is a weak Roman dominating function (WRDF) if each vertex u with f ( u ) = 0 is adjacent to a vertex v with f ( v ) > 0 such that the function f ′ : V → { 0 , 1 , 2 } defined by f ′ ( u ) = 1 , f ′ ( v ) = f ( v ) − 1 and f ′ ( w ) = f ( w ) if w ∈ V − { u , v } , has no undefended vertex. The weight of f is w ( f ) = ∑ v ∈ V f ( v ) . The weak Roman domination number, denoted by γ r ( G ) , is the minimum weight of a weak Roman dominating function on G . In this paper we examine the effects on γ r ( G ) when G is modified by deleting a vertex.

      PubDate: 2018-02-26T18:40:01Z
      DOI: 10.1016/j.akcej.2017.12.003
       
  • On n-connected splitting matroids

    • Authors: Y.M. Borse; Ganesh Mundhe
      Abstract: Publication date: Available online 26 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Y.M. Borse, Ganesh Mundhe
      In general, the splitting operation on a binary matroid M does not preserve the connectivity of M . In this paper, we provide sufficient conditions to preserve n -connectedness of a binary matroid under splitting operation. As a consequence, for an ( n + 1 ) -connected binary matroid M , we give a precise characterization of when the splitting matroid M T is n -connected.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.12.001
       
  • 2-swappable graphs

    • Authors: Sylwia Cichacz; Irmina A. Zioło
      Abstract: Publication date: Available online 23 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Sylwia Cichacz, Irmina A. Zioło
      Let G = ( V , E ) be a graph, by V 2 , we mean the set of all 2-combinations of V . We say that a graph G is k -swappable if for every edge e ∈ E , there are two sets A ⊂ E , B ⊂ V 2 ∖ E such that e ∈ A , A ≤ k , and G ≅ ( V , ( E ∖ A ) ∪ B ) . The swapping number of G is the minimum k > 0 such that G is k -swappable. Let d ≥ 2 be an integer. Every tree with exactly one vertex of degree d and remaining vertices of degree d + 1 or 1 we will call a d -nary tree. In this paper we give sufficient conditions for general graphs as well as sufficient and necessary conditions for a d -nary tree for d > 2 to be 2-swappable.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.11.002
       
  • Domination in Cayley graphs: A survey

    • Authors: T. Tamizh Chelvam; M. Sivagami
      Abstract: Publication date: Available online 21 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): T. Tamizh Chelvam, M. Sivagami
      Let Ω be a symmetric generating set of a finite group Γ . Assume that ( Γ , Ω ) be such that Γ = 〈 Ω 〉 and Ω satisfies the two conditions C 1 : the identity element e ⁄ ∈ Ω and C 2 : if a ∈ Ω , then a − 1 ∈ Ω . Given ( Γ , Ω ) satisfying C 1 and C 2 , define a Cayley graph G = C a y ( Γ , Ω ) with V ( G ) = Γ and E ( G ) = { ( x , y ) a x , y ∈ Γ , a ∈ Ω and y = x a } . When Γ = Z n = 〈 Ω 〉 , it is called as circulant graph and denoted by C i r ( n , Ω ) . In this paper, we give a survey about the results on dominating sets in Cayley graphs and circulant graphs.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.11.005
       
  • On the size of two families of unlabeled bipartite graphs

    • Authors: Abdullah Atmaca; A. Yavuz Oruç
      Abstract: Publication date: Available online 21 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Abdullah Atmaca, A. Yavuz Oruç
      Let B u ( n , r ) denote the set of unlabeled bipartite graphs whose edges connect a set of n vertices with a set of r vertices. In this paper, we provide exact formulas for B u ( 2 , r ) and B u ( 3 , r ) using Polya’s Counting Theorem. Extending these results to n ≥ 4 involves solving a set of complex recurrences and remains open. In particular, the number of recurrences that must be solved to compute B u ( n , r ) is given by the number of partitions of n that is known to increase exponentially with n by Ramanujan–Hardy–Rademacher’s asymptotic formula.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.11.008
       
  • Nilpotent graphs with crosscap at most two

    • Authors: A. Mallika; R. Kala
      Abstract: Publication date: Available online 20 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): A. Mallika, R. Kala
      Let R be a commutative ring with identity. The nilpotent graph of R , denoted by Γ N ( R ) , is a graph with vertex set Z N ( R ) ∗ , and two vertices x and y are adjacent if and only if x y is nilpotent, where Z N ( R ) = { x ∈ R : x y is nilpotent, for some y ∈ R ∗ } . In this paper, we characterize finite rings (up to isomorphism) with identity whose nilpotent graphs can be embedded in the projective plane or Klein bottle. Also, we classify finite rings whose nilpotent graphs are ring graph or outerplanarity index 1,2.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.11.006
       
  • Results on Laplacian spectra of graphs with pockets

    • Authors: Sasmita Barik; Gopinath Sahoo
      Abstract: Publication date: Available online 20 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Sasmita Barik, Gopinath Sahoo
      Let F , H v be simple connected graphs on n and m + 1 vertices, respectively. Let v be a specified vertex of H v and u 1 , … , u k ∈ F . Then the graph G = G [ F , u 1 , … , u k , H v ] obtained by taking one copy of F and k copies of H v , and then attaching the i th copy of H v to the vertex u i , i = 1 , … , k , at the vertex v of H v (identify u i with the vertex v of the i th copy) is called a graph with k pockets. In 2008, Barik raised the question that ‘how far can the Laplacian spectrum of G be described by using the Laplacian spectra of F and H v '’ and discussed the case when deg ( v ) = m in H v . In this article, we study the problem for more general cases and describe the Laplacian spectrum. As an application, we construct new nonisomorphic Laplacian cospectral graphs from the known ones.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.11.004
       
  • Zeta functions from graphs

    • Authors: Simon Davis
      Abstract: Publication date: Available online 19 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Simon Davis
      The location of the nontrivial poles of a generalized zeta function is derived from the spectrum of Ramanujan graphs and bounds are established for irregular graphs. The existence of a similarity transformation of the diagonal matrix given by a specified set of eigenvalues to an adjacency matrix of a graph is proven, and the method yields a set of finite graphs with eigenvalues determined approximately by a finite subset of the poles of the Ihara zeta function.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.09.007
       
  • The k-distance chromatic number of trees and cycles

    • Authors: Niranjan P.K.; Srinivasa Rao Kola
      Abstract: Publication date: Available online 18 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Niranjan P.K., Srinivasa Rao Kola
      For any positive integer k , a k -distance coloring of a graph G is a vertex coloring of G in which no two vertices at distance less than or equal to k receive the same color. The k -distance chromatic number of G , denoted by χ k G is the smallest integer α for which G has a k -distance α -coloring. In this paper, we improve the lower bound for the k -distance chromatic number of an arbitrary graph for k odd case and see that trees achieve this lower bound by determining the k -distance chromatic number of trees. Also, we find k -distance chromatic number of cycles and 2-distance chromatic number of a graph G in which every pair of cycles are edge disjoint.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.11.007
       
  • Some results for chessboard separation problems

    • Authors: Paul A. Burchett; R. Douglas Chatham
      Abstract: Publication date: Available online 15 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Paul A. Burchett, R. Douglas Chatham
      For a chessboard graph and a given graph parameter π , a π separation number is the minimum number of pawns for which some arrangement of those pawns on the board will produce a board where π has some desired value. We extend previous results on independence and domination separation. We also consider separation of other domination-related parameters.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.11.001
       
  • Lexicographic product graphs Pm[Pn] are antimagic

    • Authors: Wenhui Ma; Guanghua Dong; Yingyu Lu; Ning Wang
      Abstract: Publication date: Available online 14 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Wenhui Ma, Guanghua Dong, Yingyu Lu, Ning Wang
      A graph with q edges is called a n t i m a g i c if its edges can be labeled with 1, 2, … , q such that the sums of the labels on the edges incident to each vertex are distinct. Hartsfield and Ringel conjectured that every connected graph other than K 2 is antimagic. In this paper, through a labeling method and a modification on this labeling, we obtained that the lexicographic product graphs P m [ P n ] are antimagic.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.10.005
       
  • Client–server and cost effective sets in graphs

    • Authors: Mustapha Chellali; Teresa W. Haynes; Stephen T. Hedetniemi
      Abstract: Publication date: Available online 14 December 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Mustapha Chellali, Teresa W. Haynes, Stephen T. Hedetniemi
      For any integer k ≥ 0 , a set of vertices S of a graph G = ( V , E ) is k -cost-effective if for every v ∈ S , N ( v ) ∩ ( V ∖ S ) ≥ N ( v ) ∩ S + k . In this paper we study the minimum cardinality of a maximal k -cost-effective set and the maximum cardinality of a k -cost-effective set. We obtain Gallai-type results involving the k -cost-effective and global k -offensive alliance parameters, and we provide bounds on the maximum k -cost-effective number. Finally, we consider k -cost-effective sets that are also dominating. We show that computing the k -cost-effective domination number is NP-complete for bipartite graphs. Moreover, we note that not all trees have a k -cost-effective dominating set and give a constructive characterization of those that do.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.09.001
       
  • The adjacency spectrum of two new operations of graphs

    • Authors: Dijian Wang; Yaoping Hou; Zikai Tang
      Abstract: Publication date: Available online 20 November 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Dijian Wang, Yaoping Hou, Zikai Tang
      Let G be a graph and A = A ( G ) be its adjacency matrix. The eigenvalues μ 1 , μ 2 , … , μ n of A ( G ) are the eigenvalues of G and form the adjacency spectrum, denoted by S p e c ( G ) . In this paper, we introduce two new operations G 1 ■ k ( G 3 □ G 2 ) and ( G 4 □ G 1 ) ■ k ( G 3 □ G 2 ) , and describe the adjacency spectra of G 1 ■ k ( G 3 □ G 2 ) and ( G 4 □ G 1 ) ■ k ( G 3 □ G 2 ) of regular graphs G 1 , G 2 and arbitrarily graphs G 3 , G 4 in terms of their adjacency spectra. As the applications, we obtain some new integral spectrum graphs.

      PubDate: 2017-12-27T01:34:11Z
      DOI: 10.1016/j.akcej.2017.10.004
       
  • Normalized Laplacian spectrum of some subdivision-joins and R-joins of two
           regular graphs

    • Authors: Arpita Das; Pratima Panigrahi
      Abstract: Publication date: Available online 8 November 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Arpita Das, Pratima Panigrahi
      In this paper we determine the full normalized Laplacian spectrum of the subdivision-vertex join, subdivision-edge join, R -vertex join, and R -edge join of two regular graphs in terms of the normalized Laplacian eigenvalues of the graphs. Moreover, applying these results we find non-regular normalized Laplacian cospectral graphs.

      PubDate: 2017-11-10T18:09:09Z
      DOI: 10.1016/j.akcej.2017.10.006
       
  • Sampling contingency tables

    • Authors: Koko K. Kayibi; S. Pirzada; T.A. Chishti
      Abstract: Publication date: Available online 1 November 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Koko K. Kayibi, S. Pirzada, T.A. Chishti
      Let Ω be the set of all m × n matrices, where r i and c j are the sums of entries in row i and column j , respectively. Sampling efficiently uniformly at random elements of Ω is a problem with interesting applications in Combinatorics and Statistics. To calibrate the statistic χ 2 for testing independence, Diaconis and Gangolli proposed a Markov chain on Ω that samples uniformly at random contingency tables of fixed row and column sums. Although the scheme works well for practical purposes, no formal proof is available on its rate of convergence. By using a canonical path argument, we prove that this Markov chain is fast mixing and the mixing time τ x ( ϵ ) is given by τ x ( ϵ ) ≤ 2 c m a x ( m n ) 4 ln ( c m a x ϵ − 1 ) , where c m a x − 1 is the maximal value in a cell.

      PubDate: 2017-11-03T04:04:03Z
      DOI: 10.1016/j.akcej.2017.10.001
       
  • On irregularity strength of diamond network

    • Authors: Nurdin Hinding; Dian Firmayasari; Hasmawati Basir; Martin Bača; Andrea Semaničová-Feňovčíková
      Abstract: Publication date: Available online 28 October 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Nurdin Hinding, Dian Firmayasari, Hasmawati Basir, Martin Bača, Andrea Semaničová-Feňovčíková
      In this paper we investigate the total edge irregularity strength tes ( G ) and the total vertex irregularity strength tvs ( G ) of diamond graphs B r n and prove that tes ( B r n ) = ( 5 n − 3 ) ∕ 3 , while tvs ( B r n ) = ( n + 1 ) ∕ 3 .

      PubDate: 2017-11-03T04:04:03Z
      DOI: 10.1016/j.akcej.2017.10.003
       
  • Genus of total graphs from rings: A survey

    • Authors: T. Tamizh Chelvam; T. Asir
      Abstract: Publication date: Available online 23 October 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): T. Tamizh Chelvam, T. Asir
      Let R be a commutative ring. The total graph T Γ ( R ) of R is the undirected graph with vertex set R and two distinct vertices x and y are adjacent if x + y is a zero divisor in R . In this paper, we present a survey of results on the genus of T Γ ( R ) and three of its generalizations.

      PubDate: 2017-10-26T19:14:13Z
      DOI: 10.1016/j.akcej.2017.10.002
       
  • L(j,k)-labeling numbers of square of paths

    • Authors: Qiong Wu; Wai Chee Shiu
      Abstract: Publication date: Available online 14 August 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Qiong Wu, Wai Chee Shiu
      For j ≤ k , the L ( j , k ) -labeling arose from code assignment problem. That is, let j , k and m be positive numbers, an m - L ( j , k ) -labeling of a graph G is a mapping f : V ( G ) → [ 0 , m ] such that f ( u ) − f ( v ) ≥ j if d ( u , v ) = 1 , and f ( u ) − f ( v ) ≥ k if d ( u , v ) = 2 . The span of f is the difference between the maximum and the minimum numbers assigned by f . The L ( j , k ) -labeling number of G , denoted by λ j , k ( G ) , is the minimum span over all L ( j , k ) -labelings of G . The k th power G k of an undirected graph G is the graph with the vertex set of G in which two vertices are adjacent when their distance in G is at most k . In this paper, the L ( j , k ) -labeling numbers of P n 2 are determined for j ≤ k .

      PubDate: 2017-09-04T10:04:28Z
      DOI: 10.1016/j.akcej.2017.07.001
       
  • A graph theoretic analysis of leverage centrality

    • Authors: Roger Vargas; Abigail Waldron Anika Sharma Rigoberto Darren Narayan
      Abstract: Publication date: Available online 7 June 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Roger Vargas, Abigail Waldron, Anika Sharma, Rigoberto Flórez, Darren A. Narayan
      In 2010, Joyce et al. defined the leverage centrality of vertices in a graph as a means to analyze functional connections within the human brain. In this metric a degree of a vertex is compared to the degrees of all it neighbors. We investigate this property from a mathematical perspective. We first outline some of the basic properties and then compute leverage centralities of vertices in different families of graphs. In particular, we show there is a surprising connection between the number of distinct leverage centralities in the Cartesian product of paths and the triangle numbers.

      PubDate: 2017-06-12T20:47:55Z
       
  • m-dominating k-ended trees of l-connected graphs

    • Authors: Masao Tsugaki; Guiying Yan
      Abstract: Publication date: Available online 17 May 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Masao Tsugaki, Guiying Yan
      Let k ≥ 2 , l ≥ 1 and m ≥ 0 be integers, and let G be an l -connected graph. If there exists a subgraph X of G such that the distance between v and X is at most m for any v ∈ V ( G ) , then we say that X m -dominates G . A subset S of V ( G ) is said to be 2 ( m + 1 ) -stable if the distance between each pair of distinct vertices in S is at least 2 ( m + 1 ) . In this paper, we prove that if G does not have a 2 ( m + 1 ) -stable set of order at least k + l , then G has an m -dominating tree which has at most k leaves.

      PubDate: 2017-05-18T19:54:14Z
      DOI: 10.1016/j.akcej.2017.04.004
       
  • An improved bound for negative binomial approximation with z-functions

    • Authors: K. Teerapabolarn
      Abstract: Publication date: Available online 11 May 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): K. Teerapabolarn
      In this article, we use Stein’s method together with z -functions to give an improved bound for the total variation distance between the distribution of a non-negative integer-valued random variable X and the negative binomial distribution with parameters r ∈ R + and p = 1 − q ∈ ( 0 , 1 ) , where r q p is equal to the mean of X , E ( X ) . The improved bound is sharper than that mentioned in Teerapabolarn and Boondirek (2010). We give three examples of the negative binomial approximation to the distribution of X concerning the negative hypergeometric, Pólya and negative Pólya distributions.

      PubDate: 2017-05-13T17:13:50Z
      DOI: 10.1016/j.akcej.2017.04.005
       
  • On cyclic orthogonal double covers of circulant graphs by special infinite
           graphs

    • Authors: R. El-Shanawany; A. El-Mesady
      Abstract: Publication date: Available online 2 May 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): R. El-Shanawany, A. El-Mesady
      In this article, a technique to construct cyclic orthogonal double covers (CODCs) of regular circulant graphs by certain infinite graph classes such as complete bipartite and tripartite graphs and disjoint union of butterfly and K 1 , 2 n − 10 is introduced.

      PubDate: 2017-05-04T04:32:18Z
      DOI: 10.1016/j.akcej.2017.04.002
       
  • Some new upper bounds of ex(n;{C3,C4})

    • Authors: Novi H. Bong
      Abstract: Publication date: Available online 2 May 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Novi H. Bong
      The extremal number e x ( n ; { C 3 , C 4 } ) or simply e x ( n ; 4 ) denotes the maximal number of edges in a graph on n vertices with forbidden subgraphs C 3 and C 4 . The exact number of e x ( n ; 4 ) is only known for n up to 32 and n = 50 . There are upper and lower bounds of e x ( n ; 4 ) for other values of n . In this paper, we improve the upper bound of e x ( n ; 4 ) for n = 33 , 34 , … , 42 and also n = d 2 + 1 for any positive integer d ≠ 7 , 57 .

      PubDate: 2017-05-04T04:32:18Z
      DOI: 10.1016/j.akcej.2017.03.006
       
  • On total directed graphs of non-commutative rings

    • Authors: Kukil Kalpa Rajkhowa; Helen K. Saikia
      Abstract: Publication date: Available online 28 April 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Kukil Kalpa Rajkhowa, Helen K. Saikia
      For a non-commutative ring R , the left total directed graph of R is a directed graph with vertex set as R and for the vertices x and y , x is adjacent to y if and only if there is a non-zero r ∈ R which is different from x and y , such that r x + y r is a left zero-divisor of R . In this paper, we discuss some very basic results of left (as well as right) total directed graph of R . We also study the coloring of left total directed graph of R directed graph.

      PubDate: 2017-05-04T04:32:18Z
      DOI: 10.1016/j.akcej.2017.04.001
       
  • Edges and vertices in a unique signed circle in a signed graph

    • Authors: Richard Behr
      Abstract: Publication date: Available online 12 April 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Richard Behr
      We examine the conditions under which a signed graph contains an edge or a vertex that is contained in a unique negative circle or a unique positive circle. For an edge in a unique signed circle, the positive and negative case require the same structure on the underlying graph, but the requirements on the signature are different. We characterize the structure of the underlying graph necessary to support such an edge in terms of bridges of a circle. We then use the results from the edge version of the problem to help solve the vertex version.

      PubDate: 2017-04-19T14:59:29Z
      DOI: 10.1016/j.akcej.2017.03.004
       
  • The forcing total restrained geodetic number and the total restrained
           geodetic number of a graph: Realizability and complexity

    • Authors: H. Abdollahzadeh Ahangar; M. Najimi; V. Samodivkin; Ismael G. Yero
      Abstract: Publication date: Available online 11 April 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): H. Abdollahzadeh Ahangar, M. Najimi, V. Samodivkin, Ismael G. Yero
      Given two vertices u and v of a nontrivial connected graph G , the set I [ u , v ] consists all vertices lying on some u − v geodesic in G , including u and v . For S ⊆ V ( G ) , the set I [ S ] is the union of all sets I [ u , v ] for u , v ∈ S . A set S ⊆ V ( G ) is a total restrained geodetic set of G if I [ S ] = V ( G ) and the subgraphs induced by S and V ( G ) − S have no isolated vertex. The minimum cardinality of a total restrained geodetic set of G is the total restrained geodetic number g t r ( G ) of G and a total restrained geodetic set of G whose cardinality equals g t r ( G ) is a minimum total restrained geodetic set of G . A subset T of a minimum total restrained geodetic set S is a forcing subset for S if S is the unique minimum total restrained geodetic set of G containing T . The forcing total restrained geodetic number f t r ( S ) of S is the minimum cardinality of a forcing subset of S and the forcing total restrained geodetic number f t r ( G ) of G is the minimum forcing total restrained geodetic number among all minimum total restrained geodetic sets of G . In this article we determine all pairs a , b of integers such that f t r ( G ) = a and
      PubDate: 2017-04-19T14:59:29Z
      DOI: 10.1016/j.akcej.2017.03.007
       
  • Connected minimum secure-dominating sets in grids

    • Authors: Johnathan Barnett; Adam Blumenthal; Peter Johnson; Cadavious Jones; Ryan Matzke; Egbert Mujuni
      Abstract: Publication date: Available online 31 March 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Johnathan Barnett, Adam Blumenthal, Peter Johnson, Cadavious Jones, Ryan Matzke, Egbert Mujuni
      For any (finite simple) graph G the secure domination number of G satisfies γ s ( G ) ≥ V ( G ) 2 . Here we find a secure-dominating set S in G such that S = ⌈ V ( G ) 2 ⌉ in all cases when G is a grid, and in the majority of cases when G is a cylindrical or toroidal grid. In all such cases, S satisfies the additional requirement that G [ S ] is connected. We make note that the concept of secure-dominating sets considered in this paper is quite different from the other secure domination currently of interest. 1 1 The other sort of secure domination: A dominating set S ⊆ V ( G ) is secure dominating (in G) if and only if for every v ∈ V ( G ) ∖ S there is some u ∈ S such that ( S ∖ { u } ) ∪ { v } is dominating, in G.

      PubDate: 2017-04-04T18:32:51Z
      DOI: 10.1016/j.akcej.2017.03.003
       
  • L(3,2,1)- and L(4,3,2,1)-labeling problems on interval graphs

    • Authors: Sk Amanathulla; Madhumangal Pal
      Abstract: Publication date: Available online 23 March 2017
      Source:AKCE International Journal of Graphs and Combinatorics
      Author(s): Sk Amanathulla, Madhumangal Pal
      For a given graph G = ( V , E ) , the L ( 3 , 2 , 1 ) - and L ( 4 , 3 , 2 , 1 ) -labeling problems assign the labels to the vertices of G . Let Z ∗ be the set of non-negative integers. An L ( 3 , 2 , 1 ) - and L ( 4 , 3 , 2 , 1 ) -labeling of a graph G is a function f : V → Z ∗ such that f ( x ) − f ( y ) ≥ k − d ( x , y ) , for k = 4 , 5 respectively, where d ( x , y ) represents the distance (minimum number of edges) between the vertices x and y , and 1 ≤ d ( x , y ) ≤ k − 1 . The L ( 3 , 2 , 1 ) - and L ( 4 , 3 , 2 , 1 ) -labeling numbers of a graph G , are denoted by λ 3 , 2 , 1 ( G ) and λ 4 , 3 , 2 , 1 ( G ) and they are the difference between highest and lowest labels used in L ( 3 , 2 , 1 ) - and L ( 4 , 3 , 2 , 1 ) -labeling respectively. In this paper, for an interval graph G , it is shown that λ 3 , 2 , 1 ( G ) ≤ 6 Δ − 3 and λ 4 , 3 , 2 , 1 ( G ) ≤ 10 Δ − 6 , where Δ represents the maximum degree of the vertices of G . Also, two algorithms are designed to label an interval graph by maintaining L ( 3 , 2 , 1 ) - and L ( 4 , 3 , 2 , 1 ) -labeling conditio...
      PubDate: 2017-03-28T21:45:39Z
      DOI: 10.1016/j.akcej.2017.03.002
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.198.134.104
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-