The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Large amount of contents in the Internet have increased loads of contents servers, networks and data centers, which may degrade quality of service. To solve this problem, there is a method that some mirror servers providing the same contents are located on a network and a request is navigated to one of the mirror servers. As the location of the mirror servers affects the quality of service, it is...
This paper proposes an improved Logarithmic Maximum A Posteriori (Log-MAP) algorithm for Turbo decoding in the Third Generation Partnership Project Long Term Evolution (3GPP LTE). In the proposed algorithm, we exploit the understanding of polynomial regression function to approximately compute the logarithm term (also called correction function) in the Jacobian logarithmic function. The goal is to...
In this paper1, a method to search the subsets I and J needed in computing the unknown syndromes for the (73, 37, 13) quadratic residue (QR) code is proposed. According to the resulting I and J, one computes the unknown syndromes, and thus finds the corresponding error-locator polynomial by using an inverse-free BM algorithm. Based on the modified Chase-II algorithm, the performance of soft-decision...
In this paper, we introduce and study the Rectangle Escape Problem (REP), which is motivated by PCB bus escape routing. Given a rectangular region R and a set S of rectangles within R, the REP is to choose a direction for each rectangle to escape to the boundary of R, such that the resultant maximum density over R is minimized. We prove that the REP is NP-Complete, and show that it can be formulated...
We give efficient algorithms for volume sampling, i.e., for picking k-subsets of the rows of any given matrix with probabilities proportional to the squared volumes of the simplices defined by them and the origin (or the squared volumes of the parallelepipeds defined by these subsets of rows). This solves an open problem from the monograph on spectral algorithms by Kannan and Vempala (see Section...
The Lovász Local Lemma (LLL) is a powerful tool that gives sufficient conditions for avoiding all of a given set of "bad" events, with positive probability. A series of results have provided algorithms to efficiently construct structures whose existence is non-constructively guaranteed by the LLL, culminating in the recent breakthrough of Moser & Tardos. We show that the output distribution...
This paper considers a size constrained version of the undirected feedback vertex set problem motivated by placing wavelength converters on a WDM network efficiently, and proves that this problem is NP-complete even in several special cases. Moreover, the paper presents a simple approximation algorithm for a minimization version of the problem using an algorithm for the original minimum undirected...
Given a set system (V, S), V = {1,..., n} and S = {S1,...,Sm}, the minimum discrepancy problem is to find a 2-coloring X : V → {-1,+1}, such that each set is colored as evenly as possible, i.e. find X to minimize maxj∈|m] Σi∈sj X(i)|· In this paper we give the first polynomial time algorithms for discrepancy minimization that achieve bounds similar to those known existentially using the so-called...
Given a weighted graph, the maximum weight matching problem (MWM) is to find a set of vertex-disjoint edges with maximum weight. In the 1960s Edmonds showed that MWMs can be found in polynomial time. At present the fastest MWM algorithm, due to Gabow and Tarjan, runs in Õ(m√n) time, where m and n are the number of edges and vertices in the graph. Surprisingly, restricted versions of the problem,...
We consider the following general scheduling problem: The input consists of n jobs, each with an arbitrary release time, size, and a monotone function specifying the cost incurred when the job is completed at a particular time. The objective is to find a preemptive schedule of minimum aggregate cost. This problem formulation is general enough to include many natural scheduling objectives, such as...
We give a subexponential time approximation algorithm for the Unique Games problem. The algorithms run in time that is exponential in an arbitrarily small polynomial of the input size, nε. The approximation guarantee depends on ε, but not on the alphabet size or the number of variables. We also obtain a subexponential algorithms with improved approximations for SMALL-SET EXPANSION and MULTICUT. For...
The notion of vertex sparsification (in particular cut-sparsification) is introduced in, where it was shown that for any graph G = (V, E) and any subset of k terminals K ⊂ V, there is a polynomial time algorithm to construct a graph H = (K, EH) on just the terminal set so that simultaneously for all cuts (A,K-A), the value of the minimum cut in G separating A from K-A is approximately the same as...
The increased deployment of real-time video applications, including IPTV in home networks and remote monitoring in Internet of Things, requires new routing mechanism to support rapid and reliable real-time traffic transmission, especially in the bandwidth-limited and high link loss rate networks. In this paper, we study the problem of reliable multi-path routing with bandwidth and delay constraints...
Given a graph G = (V, E) with real-valued edge weights, the problem of correlation k-clustering with pre-clustered items is to extend a k-clustering of distinguished vertices of G (pre-clustered items) to partition all the vertices into clusters so as to minimize the total absolute weight of cut positive edges and uncut negative edges. This problem for general graphs is APX-complete. A polynomial...
K-Anonymity is a famous and widely used privacy principle for protecting private information. It requires that each tuple of a public released data table must be indistinguishable from at least other k - 1 tuples. Given a table, finding an optimal k-anonymous version is NP-hard in most previous recoding ”model”. Thus, designing an efficient algorithm to find high-quality k-anonymous version is still...
Cloud platforms enable enterprises to lease computing power in the form of virtual machines. An important problem for such enterprise users is to understand how many and what kinds of virtual machines will be needed from clouds. We formulate demand for computing power and other resources as a resource allocation problem with multiplicity, where computations that have to be performed concurrently are...
A new algorithm for the type II 2-D discrete cosine transform (2D-DCT) using Ramanujan ordered numbers is proposed. Based on the polynomial transform, the 2-D DCT with size N1 × N2, where Ni is a power of 2, can be converted to a series of one dimensional (1-D) DCT's. The proposed algorithm would be completely multiplierless with the evaluation of the cosine angles of the DCT by Ramanujan ordered...
Given an undirected graph with vertex and edge weights and a subset of vertices called terminals, the bounded size graph clustering (BSGC) problem is to partition the vertices into clusters of size at most a given budget such that each cluster contains at most one terminal and the total size of the clusters is minimized, where the size of a cluster is defined as the total vertex weight in the subset...
In this paper, we study the problem of wireless sensor network design by deploying a minimum number of additional relay nodes (to minimize network design cost) at a subset of given potential relay locationsin order to convey the data from already existing sensor nodes (hereafter called source nodes) to a Base Station within a certain specified mean delay bound. We formulate this problem in two different...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.