We present an algorithm that enumerates all the minimal triangulations of a graph in incremental polynomial time. Consequently, we get an algorithm for enumerating all the proper tree decompositions, in incremental po...
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ISBN:
(纸本)9781450341981
We present an algorithm that enumerates all the minimal triangulations of a graph in incremental polynomial time. Consequently, we get an algorithm for enumerating all the proper tree decompositions, in incremental polynomial time, where "proper" means that the tree decomposition cannot be improved by removing or splitting a bag. The algorithm can incorporate any method for (ordinary, single result) triangulation or tree decomposition, and can serve as an anytime algorithm to improve such a method. We describe an extensive experimental study of an implementation on real data from different fields. Our experiments show that the algorithm improves upon central quality measures over the underlying tree decompositions, and is able to produce a large number of high-quality decompositions.
We study linear bilevel programming problems whose lower-level objective is given by a random cost vector with known distribution. We consider the case where this distribution is nonatomic, allowing to pose the proble...
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ISBN:
(纸本)9783031327254;9783031327261
We study linear bilevel programming problems whose lower-level objective is given by a random cost vector with known distribution. We consider the case where this distribution is nonatomic, allowing to pose the problem of the leader using vertex-supported beliefs in the sense of [29]. We prove that, under suitable assumptions, this formulation turns out to be piecewise affine over the so-called chamber complex of the feasible set of the high point relaxation. We propose two algorithmic approaches to solve general problems enjoying this last property. The first one is based on enumerating the vertices of the chamber complex. The second one is a Monte-Carlo approximation scheme based on the fact that randomly drawn points of the domain lie, with probability 1, in the interior of full-dimensional chambers, where the problem (restricted to this chamber) can be reduced to a linear program.
We present an efficient algorithm which computes the set of minimal separators of a graph in O(n3) time per separator, thus gaining a factor of n2 on the current best-time algorithms for this problem. Our process is b...
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algorithms can be used to prove and to discover new theorems. This paper shows how algorithmic skills in general, and the notion of invariance in particular, can be used to derive many results from Euclid's algori...
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algorithms can be used to prove and to discover new theorems. This paper shows how algorithmic skills in general, and the notion of invariance in particular, can be used to derive many results from Euclid's algorithm. We illustrate how to use the algorithm as a verification interface (i.e., how to verify theorems) and as a construction interface (i.e., how to investigate and derive new theorems). The theorems that we verify are well-known and most of them are included in standard number-theory books. The new results concern distributivity properties of the greatest common divisor and a new algorithm for efficiently enumerating the positive rationals in two different ways. One way is known and is due to Moshe Newman. The second is new and corresponds to a deforestation of the Stern-Brocot tree of rationals. We show that both enumerations stem from the same simple algorithm. In this way, we construct a Stern-Brocot enumeration algorithm with the same time and space complexity as Newman's algorithm. A short review of the original papers by Stern and Brocot is also included. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
A lattice (d, k)-polytope is the convex hull of a set of points in dimension d whose coordinates are integers between 0 and k. Let δ(d,k) be the largest diameter over all lattice (d, k)-polytopes. We develop a comput...
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The sensor's waking strategy is critical to the sensor network. The basic mathematical model of waking strategy is TSP problem. Some typical intelligent algorithms for TSP problem model include ant colony algorith...
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ISBN:
(纸本)9789811081231;9789811081224
The sensor's waking strategy is critical to the sensor network. The basic mathematical model of waking strategy is TSP problem. Some typical intelligent algorithms for TSP problem model include ant colony algorithm, genetic algorithm and so on. On the basis of the maximum and minimum ant colony algorithm, this paper improves the following disadvantages: According to the principle of choosing the city based on the pheromone principle, the non-contract principle is added, The principle of city selection and make it in the process of selecting the city, the priority to follow the principle of non-contract;in a single path after the help of the enumeration algorithm with the special advantages, refer to the enumeration algorithm part of the results of the re-processing of the path, The path can cover the search space. The improved algorithm avoids the occurrence of stagnation to a certain extent, weakening the blindness of search. The possibility of the results is increased by 25%, single results of the calculation time is reduced by 89.79%.
A knockout tournament, also known as an elimination tournament is a very common competition scheme where competitors play a one-versus-one game with the loser eliminated from the competition and the winner advancing t...
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ISBN:
(纸本)9781728175652
A knockout tournament, also known as an elimination tournament is a very common competition scheme where competitors play a one-versus-one game with the loser eliminated from the competition and the winner advancing to the next round until there is only one competitor left. The setting of the first round of games called "seeding" naturally influences the competition. Although there is considerable amount of work in the literature on how to seed a knockout tournament to achieve some objectives, an algorithm to enumerate possible knockout tournament seedings has not been explicitly presented to the best of our knowledge. In this paper, a discussion on counting the number of possible seedings in a knockout tournament and an algorithm for effectively enumerating the seedings are proposed.
Cancer cells may mutate multiple times, from a normal state to a mutated state and vice versa. Given our sequenced data, we can model the mutation process with a phylogenetic tree. One representative model is the k-Do...
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Cancer cells may mutate multiple times, from a normal state to a mutated state and vice versa. Given our sequenced data, we can model the mutation process with a phylogenetic tree. One representative model is the k-Dollo parsimony, where all observed mutations mutate from a single normal cell and each character of a cell is gained at most once and lost at most k times. We examine the 1-Dollo Phylogeny problem, does a 1-Dollo phylogeny, a tree that follows the 1-Dollo parsimony model, exist for the observations. Current algorithms to solve the 1-Dollo Phylogeny problem only tell us whether or not a set of observations has a 1-Dollo phylogeny by outputting a single solution. We explore the structure of 1-Dollo phylogenies and use our idea of a skeleton to develop an algorithm that enumerates all 1-Dollo phylogenies for any set of observations. This algorithm runs much faster than the naive brute force enumeration algorithm for random input. The implementation is here: https://***/sxie12/skeleton_solver.
Background: MicroRNAs (miRNAs) are an abundant class of small noncoding RNAs (20-24 nts) that can affect gene expression by post-transcriptional regulation of mRNAs. They play important roles in several biological pro...
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Background: MicroRNAs (miRNAs) are an abundant class of small noncoding RNAs (20-24 nts) that can affect gene expression by post-transcriptional regulation of mRNAs. They play important roles in several biological processes (e. g., development and cell cycle regulation). Numerous bioinformatics methods have been developed to identify the function of miRNAs by predicting their target mRNAs. Some viral organisms also encode miRNAs, a fact that contributes to the complex interactions between viruses and their hosts. A need arises to understand the functional relationship between viral and host miRNAs and their effect on viral and host genes. Our approach to meet this challenge is to identify modules where viral and host miRNAs cooperatively regulate host gene expression. Results: We present a method to identify groups of viral and host miRNAs that cooperate in post-transcriptional gene regulation, and their target genes that are involved in similar biological processes. We call these groups (genes and miRNAs of human and viral origin) - modules. The modules are found in a new two-stage procedure, which we call bi-targeting, and is presented in this paper. The stages are (i) a new and efficient target prediction, and (ii) a new method for clustering objects of three different data types. In this work we integrate multiple information sources, including miRNA-target binding information, miRNA expression profiles, and GO annotations. Our hypotheses and the methods have been tested on human and Epstein Barr virus (EBV) miRNAs and human genes, for which we found 34 modules. We provide supporting evidence from biological and medical literature for two of our modules. Our code and data are available at http://***/similar to vaksler/*** Conclusions: The presented algorithm, which makes use of diverse biological data, is demonstrated to be an efficient approach for finding bi-targeting modules of viral and human miRNAs. These modules can contribute to a
This article introduces the concept of minimal structure (MSTR) and presents an enumeration algorithm for the synthesis of heat exchanger networks based on MSTR. Minimal Structures refer to a class of heat exchanger n...
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This article introduces the concept of minimal structure (MSTR) and presents an enumeration algorithm for the synthesis of heat exchanger networks based on MSTR. Minimal Structures refer to a class of heat exchanger networks featuring acyclic heat transfer networks without energy loops. The enumerations used are either exhaustive or smart with a stopping criterion. Without loss of generality we use the isothermal mixing Synheat model, that is, the method applies identically to other superstructures, with likely variations in the optimization models associated to each step. A conjecture is used to state that the algorithm renders solutions that are globally optimal. Literature examples are used to demonstrate the capabilities of the enumeration algorithm. Most of our solutions compare favorably with the best reported ones in literature, with exceptions where the reported solution is not minimal.
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