Wavelet FIR filter architecture using Pipe lined Addition Reordering (PAR) technique is designed and presented in this paper. The average adder cost and computation time for the proposed PAR algorithm is compared with...
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ISBN:
(纸本)9780769538921
Wavelet FIR filter architecture using Pipe lined Addition Reordering (PAR) technique is designed and presented in this paper. The average adder cost and computation time for the proposed PAR algorithm is compared with other existing graphical algorithms. Experimental results show that PAR algorithm reduces the hardware cost by 14% compared to RAG-n (Reduced Adder graph) and 17% compared to BIM (Modified Bull and Horrocks) algorithm. The speed of the circuit is found to increase by a factor of 3.7 when compared to ordinary addition reordering technique. The proposed algorithm is significant due to the increased throughput, low average power dissipation and reduced latency.
We consider distributed algorithms for approximate maximum matching on general graphs. Our main result is a randomized (4 + epsilon)-approximation distributed algorithm for maximum weighted matching, whose running tim...
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We consider distributed algorithms for approximate maximum matching on general graphs. Our main result is a randomized (4 + epsilon)-approximation distributed algorithm for maximum weighted matching, whose running time is O(log n) for any constant epsilon > 0, where n is the number of nodes in the graph. This is, to the best of our knowledge, the first log-time distributed algorithm that achieves constant approximation for maximum weighted matching on general graphs. In addition, we consider the dynamic case, where nodes are inserted and deleted one at a time. For unweighted dynamic graphs, we give a distributed algorithm that maintains a (1 + epsilon)-approximation in O(1/epsilon) time for each node insertion or deletion for any constant epsilon > 0. For weighted dynamic graphs we give a constant-factor approximation distributed algorithm that runs in constant time for each insertion or deletion.
One of the fundamental assumptions for machine-learning based text classification systems is that the underlying distribution from which the set of labeled-text is drawn is identical to the distribution from which the...
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ISBN:
(纸本)9789896740115
One of the fundamental assumptions for machine-learning based text classification systems is that the underlying distribution from which the set of labeled-text is drawn is identical to the distribution from which the text-to-be-labeled is drawn. However, in live news aggregation sites, this assumption is rarely correct. Instead, the events and topics discussed in news stories dramatically change over time. Rather than ignoring this phenomenon, we attempt to explicitly model the transitions of news stories and classifications over time to label stories that may be acquired months after the initial examples are labeled. We test our system, based on efficiently propagating labels in time-based graphs, with recently published news stories collected over an eighty day period. Experiments presented in this paper include the use of training labels from each story within the first several days of gathering stories, to using a single story as a label.
Given a task T, a pool of individuals X with different skills, and a social network G that captures the compatibility among these individuals, we study the problem of finding X, a subset of X, to perform the task. We ...
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ISBN:
(纸本)9781605584959
Given a task T, a pool of individuals X with different skills, and a social network G that captures the compatibility among these individuals, we study the problem of finding X, a subset of X, to perform the task. We call this the TEAM FORMATION problem. We require that members of X' not only meet the skill requirements of the task, but can also work effectively together as a team. We measure effectiveness using the communication cost incurred by the subgraph in G that only involves X'. We study two variants of the problem for two different communication-cost functions, and show that both variants are NP-hard. We explore their connections with existing combinatorial problems and give novel algorithms for their solution. To the best of our knowledge, this is the first work to consider the TEAM FORMATION problem in the presence of a social network of individuals. Experiments on the DBLP dataset show that our framework works well in practice and gives useful and intuitive results.
In this paper we define and study a family of optimization problems called FERRY problems, which may be viewed as generalizations of the classical wolf-goat-cabbage puzzle. We present the FERRY COVER problem (FC), whe...
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ISBN:
(纸本)9783540729136
In this paper we define and study a family of optimization problems called FERRY problems, which may be viewed as generalizations of the classical wolf-goat-cabbage puzzle. We present the FERRY COVER problem (FC), where the objective is to determine the minimum required boat size to safely transport n items represented by a graph G and demonstrate a close connection with VERTEX COVER which leads to hardness and approximation results. We also completely solve the problem on trees. Then we focus on a variation of the same problem with the added constraint that only 1 round-trip is allowed (FC1). We present a reduction from MAX-NAE{3}-SAT which shows that this problem is NP-hard and APX-hard. We also provide an approximation algorithm for bipartite graphs with a factor asymptotically equal to 4/3 and a 1.56-approximation algorithm for planar graphs. Finally, we generalize the above problem to define FCm, where at most m round-trips are allowed, and MFTk, which is the problem of minimizing the number of round-trips when the boat capacity is k. We present some preliminary lemmata for both, which provide bounds on the value of the optimal solution, and relate them to FC.
Let G = (V, E) be an edge-weighted graph, and let v)(H) denote the sum of the weights of the edges in a subgraph H of G. Given a positive integer k, the balanced tree partitioning problem requires to cover all vertice...
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ISBN:
(纸本)9783642002014
Let G = (V, E) be an edge-weighted graph, and let v)(H) denote the sum of the weights of the edges in a subgraph H of G. Given a positive integer k, the balanced tree partitioning problem requires to cover all vertices in V by a set T of k trees of the graph so that the ratio a of max(T is an element of T) w(T) to w(T*)/k is minimized, where T* denotes a minimum spanning tree of G. The problem has been used as a core analysis in designing approximation algorithms for several types of graph partitioning problems over metric spaces, and the performance guarantees depend on the ratio alpha of the corresponding balanced tree partitioning problems. It is known that the best possible value of alpha is 2 for the general metric space. In this paper, we study the problem in the d-dimensional Euclidean space R-d, and break the bound 2 on alpha, showing that alpha < 2 root 3 - 3/2 = 1.964 for d >= 3 and alpha < (13 + root 109)/12 = 1.953 for d = 2. These new results enable us to directly improve the performance guarantees of several existing approximation algorithms for graph partitioning problems if the metric space is an Euclidean space.
We show that the multicut problem is APX-hard in directed acyclic graphs, even with three source-sink pairs. We also show that it is tractable in planar graphs with a fixed number of terminals, and even FPT if all the...
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A multimedia programming approach for the generalized graph search (traversal) algorithms is considered. It is based on a concept of cyberFilm, which is a set of multi-media frames defining algorithmic features. Throu...
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ISBN:
(纸本)0889865450
A multimedia programming approach for the generalized graph search (traversal) algorithms is considered. It is based on a concept of cyberFilm, which is a set of multi-media frames defining algorithmic features. Through these frames, the user can represent computational steps and specify "activity" within the steps. Each set of multimedia frames, represented by a special icon, is supported by a set of template programs to generate corresponding executable codes. Such icons and sets of template programs behind them provide powerful repetitive-type constructs for specifying computational algorithms. The main contributions of this paper are an introduction of a cyberFilm developed for the generalized graph search algorithms and a description of the template programs supporting this cyberFilm. 505-086 in display pdf
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