Considering fairness has become increasingly important in recent research. This paper proposes the prize-collecting vertex cover problem with fairness constraints (FPCVC). In a prize-collecting vertex cover problem, t...
详细信息
Considering fairness has become increasingly important in recent research. This paper proposes the prize-collecting vertex cover problem with fairness constraints (FPCVC). In a prize-collecting vertex cover problem, those edges that are not covered incur penalties. By adding fairness concerns into the problem, the vertex set is divided into l groups, the goal is to find a vertex set to minimize the cost-plus-penalty value under the constraints that the profit of edges collected by each group exceeds a coverage requirement. In this paper, we propose a hybrid algorithm (combining deterministic rounding and randomized rounding) for the FPCVC problem which, with probability at least 1-1/l alpha\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1-1/l<^>{\alpha }$$\end{document}, returns a feasible solution with an objective value at most 9(alpha+1)2lnl+3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left( \frac{9(\alpha +1)}{2}\ln l+3\right) $$\end{document} times that of an optimal solution, where alpha\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha $$\end{document} is a constant. We also show a lower bound of Omega(lnl)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega (\ln l)$$\end{document} for the approximability of FPCVC. Thus, our approxima
For a given graph G, the minimum weight connected-k-subgraph cover problem (MinWCkSC) is to find a minimum weight vertex subset C of G such that each connected subgraph of G on k vertices contains at least one vertex ...
详细信息
For a given graph G, the minimum weight connected-k-subgraph cover problem (MinWCkSC) is to find a minimum weight vertex subset C of G such that each connected subgraph of G on k vertices contains at least one vertex of C. Previously, Zhang et al. [37] presented a (k - 1)-approximation algorithm for MinWCkSC under the assumption that the girth of G, which is the length of a shortest cycle of G, is at least k. In this paper, we improve this result by showing that (k - 1)-approximation can be achieved when the girth requirement is relaxed from k to 2k/3. (C) 2020 Elsevier B.V. All rights reserved.
Let H = (V, epsilon) be a hypergraph with maximum edge size l and maximum degree Delta. For a given positive integers b(v), v is an element of V, a set multicover in H is a set of edges C subset of epsilon such that e...
详细信息
Let H = (V, epsilon) be a hypergraph with maximum edge size l and maximum degree Delta. For a given positive integers b(v), v is an element of V, a set multicover in H is a set of edges C subset of epsilon such that every vertex v in V belongs to at least b(v) edges in C. Set multicover is the problem of finding a minimum-cardinality set multicover. Peleg, Schechtman and Wool conjectured that for any fixed Delta and b := min(v is an element of V) b(v), the problem of set multicover is not approximablewithin a ratio less than delta :=Delta-b+1, unlessP = NP. Hence it's a challenge to explore for which classes of hypergraph the conjecture doesn't hold. We present a polynomial time algorithm for the set multicover problem which combines a deterministic threshold algorithm with conditioned randomized rounding steps. Our algorithm yields an approximation ratio of max {148/149 delta, (1 - (b-1)e(delta/4)/94l)delta} for b >= 2 and delta >= 3. Our result not only improves over the approximation ratio presented by El Ouali et al. (algorithmica 74:574, 2016) but it's more general since we set no restriction on the parameter l. Moreover we present a further polynomial time algorithm with an approximation ratio of 5/6 delta for hypergraphs with l <= (1 + epsilon)(l) over bar for any fixed epsilon is an element of [0, 1/2], where (l) over bar is the average edge size. The analysis of this algorithm relies on matching/covering duality due to Ray-Chaudhuri (1960), which we convert into an approximative form. The second performance disprove the conjecture of Peleg et al. for a large subclass of hypergraphs.
The problem of efficiently monitoring the network flow is regarded as the problem to find out the minimum weighted weak vertex cover set for a given graphG=(V,E). In this paper, we give an approximation algorithm to s...
详细信息
The problem of efficiently monitoring the network flow is regarded as the problem to find out the minimum weighted weak vertex cover set for a given graphG=(V,E). In this paper, we give an approximation algorithm to solve it, which has the approximation ratio lnd+1, whered is the maximum degree of the vertex in graphG, and improve the previous work.
Keywords weak vertex cover - NP-hard - approximation algorithm
Note
This work is supported by the Ministry of Science and Technology of China (Grant No.2001CCA03000), the National Natural Science Foundation of China (Grant No.60273045), and the Shanghai Science and Technology Development Foundation (Grant No.025115032).
The problem of assigning power levels to the nodes of a wireless sensor network from a given a set of two power levels is called Dual power management problem and the underlying network is called Dual power network. W...
详细信息
The problem of assigning power levels to the nodes of a wireless sensor network from a given a set of two power levels is called Dual power management problem and the underlying network is called Dual power network. We consider the problem of minimizing the maximum receiver interference of such a network. The interference disrupts the communication and forces the data packets to be retransmitted. The motivation is to conserve the energy by minimizing the interference and maintaining the connectivity of the dual power network. Receiver interference problem is proved to be NP-hard. In this paper, an approximation algorithm is derived for minimizing the maximum receiver interference of a dual power network by utilizing the approximation algorithm for Dual Power Management Problem. The proposed algorithm is supported by the simulation results. We term this problem as Dual Power Receiver Interference Problem and show that it is NP-complete using a polynomial time reduction from Degree Constrained Minimum Spanning Tree problem. We also prove the NP-completeness of Dual Power Management Problem by a polynomial reduction from Vertex Cover Problem.
Steiner tree problem is a typical NP-hard problem, which has vast application background and has been an active research topic in recent years. Stochastic optimization problem is an important branch in the field of op...
详细信息
Steiner tree problem is a typical NP-hard problem, which has vast application background and has been an active research topic in recent years. Stochastic optimization problem is an important branch in the field of optimiza-tion. Compared with deterministic optimization problem, it is an optimization problem with random factors, and requires the use of tools such as probability and statistics, stochastic process and stochastic analysis. In this paper, we study a two-stage finite-scenario stochastic prize-collecting Steiner tree prob-lem, where the goal is to minimize the sum of the first stage cost, the expected second stage cost and the expected penalty cost. Our main contribution is to present a primal-dual 3-approximation algorithm for this problem.
We study the problem Of MINIMIZING TOTAL LATENCY IN MACHINE SCHEDULING WITH DELIVERIES, which is defined as follows. There is a set of n jobs to be processed by a single machine at a plant, where job J(i) is associate...
详细信息
We study the problem Of MINIMIZING TOTAL LATENCY IN MACHINE SCHEDULING WITH DELIVERIES, which is defined as follows. There is a set of n jobs to be processed by a single machine at a plant, where job J(i) is associated with its processing time and a customer i located at location i to which the job is to be delivered. In addition, there is a single uncapacitated delivery vehicle available. All jobs (vehicle) are available for processing (delivery) at time 0. Our aim is to determine the sequence in which the jobs should be processed in the plant, the departure times of the vehicle from the plant, and the routing of the vehicle, so as to minimize the total latency (job delivery time). We present a 6e similar to 16.309691-approximation algorithm for the problem. (C) 2007 Elsevier B.V. All rights reserved.
The k-means problem is a classical combinatorial optimization problem which has lots of applications in many fields such as machine learn-ing, data mining, etc. We consider a variant of k-means problem in the spherica...
详细信息
The k-means problem is a classical combinatorial optimization problem which has lots of applications in many fields such as machine learn-ing, data mining, etc. We consider a variant of k-means problem in the spherical space, that is, spherical k-means problem with penalties. In the problem, it is allowable that some nodes in the spherical space can not be clustered by paying some penalty costs. Based on local search scheme, we propose a (4(11 + 4 root 7) + epsilon)-approximation algorithm using singe-swap oper-ation, where E is a positive constant.
Trade-offs between energy and performance are important for energy-aware scheduling. Recently, a novel model, called energy-aware profit maximizing scheduling problem (EAPM), which combines energy and makespan into th...
详细信息
Trade-offs between energy and performance are important for energy-aware scheduling. Recently, a novel model, called energy-aware profit maximizing scheduling problem (EAPM), which combines energy and makespan into the objective of maximizing the profit per unit of time has been proposed. The user pay a given price to have a bag-of-tasks processed and the objective is to maximize the profit per unit time. In this study, we design a polynomial-time algorithm for the EAPM problem. The execution time of our algorithm is polynomial in the number of task types which is an improvement over the previous algorithm, whose execution time is polynomial in the number of tasks. Moreover, we demonstrate that the approximation ratio of our algorithm is close to 2 for a special case, which may be the best result we can obtain. Experimental results show that our algorithm can produce a feasible solution with better objective value than the previous algorithm. (C) 2018 Published by Elsevier Inc.
作者:
Feng, WangsenZhang, Li'angWang, HanpinPeking Univ
Ctr Comp Minist Educ Key Lab Network & Software Secur Assurance Beijing 100871 Peoples R China Peking Univ
Sch Elect Engn & Comp Sci Minist Educ Key Lab High Confidence Software Technol Beijing 100871 Peoples R China
We propose a polynomial time approximation algorithm for a novel maximum edge coloring problem which arises from wireless mesh networks [Ashish Raniwala, Tzi-cker Chiueh, Architecture and algorithms for an IEEE 802.11...
详细信息
We propose a polynomial time approximation algorithm for a novel maximum edge coloring problem which arises from wireless mesh networks [Ashish Raniwala, Tzi-cker Chiueh, Architecture and algorithms for an IEEE 802.11-based multi-channel wireless mesh network, in: INFOCOM 2005, pp. 2223-2234;Ashish Raniwala, Kartik Gopalan, Tzi-cker Chiueh, Centralized channel assignment and routing algorithms for multi-channel wireless mesh networks, Mobile Comput. Commun. Rev. 8 (2) (2004) 50-65]. The problem is to color all the edges in a graph with maximum number of colors under the following q-Constraint: for every vertex in the graph, all the edges incident to it are colored with no more than q (q is an element of Z, q >= 2) colors. We show that the algorithm is a 2-approximation for the case q = 2 and a (1 + 4q-2/3q(2)-5q+2)-approximation for the case q > 2 respectively. The case q = 2 is of great importance in practice. For complete graphs and trees, polynomial time accurate algorithms are found for them when q = 2. The approximation algorithm gives a feasible solution to channel assignment in multi-channel wireless mesh networks. (C) 2008 Elsevier B.V. All rights reserved.
暂无评论