Results 41 to 50 of about 35,538 (168)

On the Complexity of Reinforcement in Graphs

Discussiones Mathematicae Graph Theory, 2016
We show that the decision problem for p-reinforcement, p-total rein- forcement, total restrained reinforcement, and k-rainbow reinforcement are NP-hard for bipartite graphs.
Rad Nader Jafari
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Restricted optimal pebbling is NP-hard

Discrete Applied Mathematics, 2023
Consider a distribution of pebbles on a graph. A pebbling move removes two pebbles from a vertex and place one at an adjacent vertex. A vertex is reachable under a pebble distribution if it has a pebble after the application of a sequence of pebbling moves. A pebble distribution is solvable if each vertex is reachable under it.
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Unshuffling a square is NP-hard

Journal of Computer and System Sciences, 2014
A shuffle of two strings is formed by interleaving the characters into a new string, keeping the characters of each string in order. A string is a square if it is a shuffle of two identical strings. There is a known polynomial time dynamic programming algorithm to determine if a given string z is the shuffle of two given strings x,y; however, it has ...
Buss, Sam, Soltys, Michael
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A Column Generation-Based Lower Bound for the Minimum Sum Coloring Problem

IEEE Access, 2020
The objective of this paper is to derive a tight and efficient lower bound for the minimum sum coloring problem. This NP-hard problem is a variant of the classical graph coloring problem where the objective is to minimize the sum of the colors.
Mehdi Mrad, Olfa Harrabi, Jouhaina Chaouachi Siala, Anis Gharbi   +3 more
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The STO-problem is NP-hard

Journal of Symbolic Computation, 1994
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Apt, K.R., van Emde Boas, P., Welling, A.   +2 more
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PrxCa1−xMnO3 based stochastic neuron for Boltzmann machine to solve “maximum cut” problem

APL Materials, 2019
The neural network enables efficient solutions for Nondeterministic Polynomial-time (NP) hard problems, which are challenging for conventional von Neumann computing.
Devesh Khilwani, Vineet Moghe, Sandip Lashkare, Vivek Saraswat, Pankaj Kumbhare, Maryam Shojaei Baghini, Srivatsava Jandhyala, Sreenivas Subramoney, Udayan Ganguly   +8 more
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The Dual Characterization of Structured and Skewed Structured Singular Values

Mathematics, 2022
The structured singular values and skewed structured singular values are the well-known mathematical quantities and bridge the gap between linear algebra and system theory.
Mutti-Ur Rehman, Jehad Alzabut, Taqwa Ateeq, Jutarat Kongson, Weerawat Sudsutad   +4 more
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Grassmannian Optimization Is NP-Hard

SIAM Journal on Optimization
We show that unconstrained quadratic optimization over a Grassmannian $\operatorname{Gr}(k,n)$ is NP-hard. Our results cover all scenarios: (i) when $k$ and $n$ are both allowed to grow; (ii) when $k$ is arbitrary but fixed; (iii) when $k$ is fixed at its lowest possible value $1$. We then deduce the NP-hardness of unconstrained cubic optimization over
Zehua Lai, Lek-Heng Lim, Ke Ye
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Unique Perfect Phylogeny Is NP-Hard [PDF]

, 2011
We answer, in the affirmative, the following question proposed by Mike Steel as a $100 challenge: "Is the following problem NP-hard? Given a ternary phylogenetic X-tree T and a collection Q of quartet subtrees on X, is T the only tree that displays Q ?"
Habib, Michel, Stacho, Juraj
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Ising formulations of many NP problems

Frontiers in Physics, 2014
We provide Ising formulations for many NP-complete and NP-hard problems, including all of Karp's 21 NP-complete problems. This collects and extends mappings to the Ising model from partitioning, covering and satisfiability.
Andrew eLucas
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