University of Tehran Journal of Algorithms and Computation 2476-2776 49 1 2017 06 01 Theta Graph Designs 1 16 7963 10.22059/jac.2017.7963 EN Anthony D. Forbes Department of Mathematics and Statistics, The Open University, Milton Keynes MK7 6AA, UK. Terry S. Griggs Department of Mathematics and Statistics, The Open University, Milton Keynes MK7 6AA, UK. Tamsin J. Forbes 22 St Albans Road, Kingston upon Thames KT2 5HQ, UK Journal Article 2018 01 19 We solve the design spectrum problem for all theta graphs with 10, 11, 12, 13, 14 and 15 edges. https://jac.ut.ac.ir/article_7963_0512bf59e0fecd0dc77de2de97c2c8c6.pdf
University of Tehran Journal of Algorithms and Computation 2476-2776 49 1 2017 06 01 Remainder Cordial Labeling of Graphs 17 30 7965 10.22059/jac.2017.7965 EN R. Ponraj Department of Mathematics, Sri Paramakalyani College, Alwarkurichi{627 412, India K. Annathurai Department of Mathematics, Thiruvalluvar College,, Papanasam{627 425, India R. Kala Department of Mathematics, Manonmaniam Sundaranar University, Tirunelveli{ 627 012, India. Journal Article 2018 01 19 In this paper we introduce remainder cordial labeling of graphs. Let $G$ be a $(p,q)$ graph. Let $f:V(G)\rightarrow \{1,2,...,p\}$ be a $1-1$ map. For each edge $uv$ assign the label $r$ where $r$ is the remainder when $f(u)$ is divided by $f(v)$ or $f(v)$ is divided by $f(u)$ according as $f(u)\geq f(v)$ or $f(v)\geq f(u)$. The function$f$ is called a remainder cordial labeling of $G$ if $\left| e_{f}(0) - e_f(1) \right|\leq 1$ where $e_{f}(0)$ and $e_{f}(1)$ respectively denote the number of edges labelled with even integers and odd integers. A graph $G$ with a remainder cordial labeling is called a remainder cordial graph. We investigate the remainder cordial behavior of path, cycle, star, bistar, crown, comb, wheel, complete bipartite $K_{2,n}$ graph. Finally we propose a conjecture on complete graph $K_{n}$. https://jac.ut.ac.ir/article_7965_9bf96b3c6575b2e98518384f18e0de66.pdf
University of Tehran Journal of Algorithms and Computation 2476-2776 49 1 2017 06 01 Asteroidal number for some product graphs 31 43 7979 10.22059/jac.2017.7979 EN S. ALAGU Department of Mathematics, Manonmaniam Sundaranar University, Tirunelveli - 627 012, Tamilnadu, India R. KALA Department of Mathematics, Manonmaniam Sundaranar University, Tirunelveli - 627 012, Tamilnadu, India Journal Article 2016 11 27 The notion of Asteroidal triples was introduced by Lekkerkerker and Boland . D.G.Corneil and others , Ekkehard Kohler  further investigated asteroidal triples. Walter generalized the concept of asteroidal triples to asteroidal sets . Further study was carried out by Haiko Muller . In this paper we find asteroidal numbers for Direct product of cycles, Direct product of path and cycle, Strong product of paths and cycles and some more graphs. https://jac.ut.ac.ir/article_7979_01beaa9142c979dd177ee0b4e047fdf0.pdf
University of Tehran Journal of Algorithms and Computation 2476-2776 49 1 2017 06 01 Edge-tenacity in Networks 45 53 7980 10.22059/jac.2017.7980 EN Dara Moazzami University of Tehran, College of Engineering, Department of Engineering Science Journal Article 2016 08 30 Numerous networks as, for example, road networks, electrical networks and communication networks can be modeled by a graph. Many attempts have been made to determine how well such a network is "connected" or stated differently how much effort is required to break down communication in the system between at least some nodes. Two well-known measures that indicate how "reliable" a graph is are the "Tenacity" and "Edge-tenacity" of a graph. In this paper we present results on the tenacity and edge-tenacity, $T_e(G)$, a new invariant, for several classes of graphs. Basic properties and some bounds for edge-tenacity, $T_e(G)$, are developed. Edge-tenacity values for various classes of graphs are calculated and future work andconcluding remarks are summarized https://jac.ut.ac.ir/article_7980_d39c785dea8c5952d0d192f44c767675.pdf
University of Tehran Journal of Algorithms and Computation 2476-2776 49 1 2017 06 01 Linear optimization on the intersection of two fuzzy relational inequalities defined with Yager family of t-norms 55 82 7981 10.22059/jac.2017.7981 EN Amin Ghodousian Faculty of Engineering Science, College of Engineering, University of Tehran, P.O.Box 11365-4563, Tehran, Iran Reza Zarghani School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, 11155-4563, Iran Journal Article 2016 05 03 In this paper, optimization of a linear objective function with fuzzy relational inequality constraints is investigated where the feasible region is formed as the intersection of two inequality fuzzy systems and Yager family of t-norms is considered as fuzzy composition. Yager family of t-norms is a parametric family of continuous nilpotent t-norms which is also one of the most frequently applied one. This family of t-norms is strictly increasing in its parameter and covers the whole spectrum of t-norms when the parameter is changed from zero to infinity. The resolution of the feasible region of the problem is firstly investigated when it is defined with max-Yager composition. Based on some theoretical results, conditions are derived for determining the feasibility. Moreover, in order to simplify the problem, some procedures are presented. It is shown that a lower bound is always attainable for the optimal objective value. Also, it is proved that the optimal solution of the problem is always resulted from the unique maximum solution and a minimal solution of the feasible region. A method is proposed to generate random feasible max-Yager fuzzy relational inequalities and an algorithm is presented to solve the problem. Finally, an example is described to illustrate these algorithms https://jac.ut.ac.ir/article_7981_efef0843919600ca87fd333cdebadf64.pdf
University of Tehran Journal of Algorithms and Computation 2476-2776 49 1 2017 06 01 Tenacity and some related results 83 91 7986 10.22059/jac.2017.7986 EN Dara Moazzami University of Tehran, College of Engineering, Department of Engineerng Science Journal Article 2016 06 30 Conceptually graph vulnerability relates to the study of graph<br />intactness when some of its elements are removed. The motivation for<br />studying vulnerability measures is derived from design and analysis<br />of networks under hostile environment. Graph tenacity has been an<br />active area of research since the the concept was introduced in<br />1992. <br />The tenacity T(G) of a graph G is defined as<br />\begin{center}<br /> $T(G)=\displaystyle \min_{A\subset V(G)}\{\frac{\mid A\mid<br /> +\tau(G-A)}{\omega(G-A)}\}$<br />\end{center}<br />where $\tau(G-A)$ denotes the order (the number of vertices) of a<br />largest component of G-A and $\omega(G-A)$ is the number of<br />components of G-A. <br />In this paper we discuss tenacity and its properties in<br />vulnerability calculation. https://jac.ut.ac.ir/article_7986_4ca995acf8ce801abe8eb3b4123a284c.pdf
University of Tehran Journal of Algorithms and Computation 2476-2776 49 1 2017 06 01 An improved algorithm to reconstruct a binary tree from its inorder and postorder traversals 93 113 7987 10.22059/jac.2017.7987 EN Niloofar Aghaieabiane Department of Engineering, School of Computer Science, New Jersey Institute of Technology, Newark, New Jersey, the USA. Henk Koppelaar Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, Delft, The Netherlands. 0000-0001-7487-6564 Peyman Nasehpour Golpayegan University of Technology, Department of Engineering Science, Golpayegan, Iran. Journal Article 2016 07 15 It is well-known that, given inorder traversal along with one of the preorder or postorder traversals of a binary tree, the tree can be determined uniquely. Several algorithms have been proposed to reconstruct a binary tree from its inorder and preorder traversals. There is one study to reconstruct a binary tree from its inorder and postorder traversals, and this algorithm takes running time of  $\BigO{\emph{n}^2}$. In this paper, we present $\proc{InPos}$ an improved algorithm to reconstruct a binary tree from its inorder and postorder traversals. The running time and space complexity of the algorithm are an order of $\BigTheta{\emph{n}}$ and $\BigTheta{\emph{n}}$ respectively, which we prove to be optimal. <br /> The $\proc{InPos}$ algorithm not only reconstructs the binary tree, but also it determines different types of the nodes in a binary tree; nodes with two children, nodes with one child, and nodes with no child. At the end, the $\proc{InPos}$ returns a matrix-based structure to represent the binary tree, and enabling  access to any structural information of the reconstructed tree in linear time with any given tree traversals.   https://jac.ut.ac.ir/article_7987_96afa0a5a26a75bad5082fc1b7e92603.pdf
University of Tehran Journal of Algorithms and Computation 2476-2776 49 1 2017 06 01 Linear optimization on Hamacher-fuzzy relational inequalities 115 150 7988 10.22059/jac.2017.7988 EN Amin Ghodousian Faculty of Engineering Science, College of Engineering, University of Tehran, P.O.Box 11365-4563, Tehran, Iran Mohammadsadegh Nouri Faculty of Engineering Science, College of Engineering, University of Tehran, P.O.Box 11365-4563, Tehran, Iran. Journal Article 2017 01 30 In this paper, optimization of a linear objective function with fuzzy relational inequality constraints is investigated where the feasible region is formed as the intersection of two inequality fuzzy systems and Hamacher family of t-norms is considered as fuzzy composition. Hamacher family of t-norms is a parametric family of continuous strict t-norms, whose members are decreasing functions of the parameter. The resolution of the feasible region of the problem is firstly investigated when it is defined with max-Hamacher composition. Based on some theoretical results, a necessary and sufficient condition and three other necessary conditions are derived for determining the feasibility. Moreover, in order to simplify the problem, some procedures are presented. It is shown that a lower bound is always attainable for the optimal objective value. Also, it is proved that the optimal solution of the problem is always resulted from the unique maximum solution and a minimal solution of the feasible region. A method is proposed to generate random feasible max-Hamacher fuzzy relational inequalities and an algorithm is presented to solve the problem. Finally, an example is described to illustrate these algorithms. https://jac.ut.ac.ir/article_7988_dbb5f79575a0d1ab22f76d1af7278869.pdf