The "Logarithmic Weighted Random Selector" (LWRS) introduces a novel algorithm designed for selecting randomly one item from a list, with the bias that the further to the beginning of the list each one is, t...
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DNA microarray technology, originally developed to measure the level of gene expression, has become one of the most widely used tools in genomic study. The crux of microarray design lies in how to select a unique prob...
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DNA microarray technology, originally developed to measure the level of gene expression, has become one of the most widely used tools in genomic study. The crux of microarray design lies in how to select a unique probe that distinguishes a given genomic sequence from other sequences. Due to its significance, probe selection attracts a lot of attention. Various probe selection algorithms have been developed in recent years. Good probe selection algorithms should produce a small number of candidate probes. Efficiency is also crucial because the data involved are usually huge. Most existing algorithms are usually not sufficiently selective and quite a large number of probes are returned. We propose a new direction to tackle the problem and give an efficient algorithm based on randomization to select a small set of probes and demonstrate that such a small set of probes is sufficient to distinguish each sequence from all the other sequences. Based on the algorithm, we have developed probe selection software RANDPS, which runs efficiently in practice. The software is available on our website (http://***/similar to cindy/RandPS/***). We test our algorithm via experiments on different genomes (Escherichia coli, Saccharamyces cercvisiae, etc.) and our algorithm is able to output unique probes for most of the genes efficiently. The other genes can be identified by a combination of at most two probes. (C) 2007 Elsevier Ltd. All rights reserved.
We recently developed a new randomized optimization framework, the Nested Partitions (NP) method. This approach uses partitioning, global random sampling, and local search heuristics to create a Markov chain that has ...
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We recently developed a new randomized optimization framework, the Nested Partitions (NP) method. This approach uses partitioning, global random sampling, and local search heuristics to create a Markov chain that has global optima as its absorbing states. This new method combines global and local search in a natural way and it is highly matched to emerging massively parallel processing capabilities. In this paper, we apply the NP method to the Travelling Salesman Problem. Preliminary numerical results show that the NP method generates high-quality solutions compared to well-known heuristic methods, and that it can be a very promising alternative for finding a solution to the TSP. (C) 1999 Elsevier Science Ltd. All rights reserved.
KNET is an environment for constructing probabilistic, knowledge-intensive systems within the axiomatic framework of decision theory. The KNET architecture defines a complete separation between the hypermedia user int...
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KNET is an environment for constructing probabilistic, knowledge-intensive systems within the axiomatic framework of decision theory. The KNET architecture defines a complete separation between the hypermedia user interface on the one hand, and the representation and management of expert opinion on the other. KNET offers a choice of algorithms for probabilistic inference. We and our coworkers have used KNET to build consultation systems for lymph-node pathology, bone-marrow transplantation therapy, clinical epidemiology, and alarm management in the intensive-care unit. Most important, KNET contains a randomized approximation scheme (RAS) for the difficult and almost certainly intractable problem of Bayesian inference. Our algorithm can, in many circumstances, perform efficient approximate inference in large and richly interconnected models of medical diagnosis. In this article, we describe the architecture of KNET, construct a randomized algorithm for probabilistic inference, and analyze the algorithm's performance. Finally, we characterize our algorithms' empiric behavior and explore its potential for parallel speedups. From design to implementation, then, KNET demonstrates the crucial interaction between theoretical computer science and medical informatics.
We present a randomized pattern formation algorithm for asynchronous oblivious (i.e., memory-less) mobile robots that enables formation of any target pattern. As for deterministic pattern formation algorithms, the cla...
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ISBN:
(纸本)9783662451748
We present a randomized pattern formation algorithm for asynchronous oblivious (i.e., memory-less) mobile robots that enables formation of any target pattern. As for deterministic pattern formation algorithms, the class of patterns formable from an initial configuration I is characterized by the symmetricity (i.e., the order of rotational symmetry) of I, and in particular, every pattern is formable from I if its symmetricity is 1. The randomized pattern formation algorithm psi(PF) we present in this paper consists of two phases: The first phase transforms a given initial configuration I into a configuration I' such that its symmetricity is 1, and the second phase invokes a deterministic pattern formation algorithm psi(CWM) by Fujinaga et al. (DISC 2012) for asynchronous oblivious mobile robots to finally form the target pattern. There are two hurdles to overcome to realize psi(PF). First, all robots must simultaneously stop and agree on the end of the first phase, to safely start the second phase, since the correctness of psi(CWM) is guaranteed only for an initial configuration in which all robots are stationary. Second, the sets of configurations in the two phases must be disjoint, so that even oblivious robots can recognize which phase they are working on. We provide a set of tricks to overcome these hurdles.
Given a set of sites in the plane, their order-k Voronoi diagram partitions the plane into regions such that all points within one region have the same k nearest sites. The order-k abstract Voronoi diagram is defined ...
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ISBN:
(纸本)9783319130750;9783319130743
Given a set of sites in the plane, their order-k Voronoi diagram partitions the plane into regions such that all points within one region have the same k nearest sites. The order-k abstract Voronoi diagram is defined in terms of bisecting curves satisfying some simple combinatorial properties, rather than the geometric notions of sites and distance, and it represents a wide class of order-k concrete Voronoi diagrams. In this paper we develop a randomized divide-and-conquer algorithm to compute the order-k abstract Voronoi diagram in expected O(kn(1+epsilon)) operations. For solving small sub-instances in the divide-and-conquer process, we also give two sub-algorithms with expected O(k(2)n log n) and O(n 2 2 a(n) log n) time, respectively. This directly implies an O(kn(1+epsilon))-time algorithm for several concrete order-k instances such as points in any convex distance, disjoint line segments and convex polygons of constant size in the L-p norm, and others.
We shall investigate randomized algorithms for solving large-scale linear inverse problems with general Tikhonov regularizations. Our first approach transforms general form inverse problems into standard form, then we...
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We shall investigate randomized algorithms for solving large-scale linear inverse problems with general Tikhonov regularizations. Our first approach transforms general form inverse problems into standard form, then we apply randomized algorithms to reduce large-scale systems of standard form to much smaller-scale systems and seek their regularized solutions in combination with some popular choice rules for regularization parameters. Our second approach involves a new random generalized SVD algorithm that can essentially reduce the sizes of the original large-scale ill-posed systems. The reduced systems can provide approximate regularized solutions with about the same accuracy as the ones by the classical generalized SVD, but they are much more stable and much less expensive as they need only to work on problems of much smaller sizes. Numerical results are presented to demonstrate the efficiency and accuracy of the algorithms.
randomized algorithms, or probabilistic algorithms, extend the notion of algorithm by introducing input of random data and random choices in the process of computation. A new mathematical theory of the semantic domain...
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An automobile consists of a large number of component parts that must be assembled. Even if all parts precisely fit together, it is not clear whether they can be assembled or not. The process of finding a suitable ass...
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ISBN:
(纸本)3540673547
An automobile consists of a large number of component parts that must be assembled. Even if all parts precisely fit together, it is not clear whether they can be assembled or not. The process of finding a suitable assembly sequence, which can be performed in reality, is called assembly planning. We present our probabilistic motion planner RAMONA developed in cooperation with Audi AG, Germany, which is used within a digital mock-up project for checking the feasibility of assembly sequences. The heart of RAMONA is a probabilistic complete motion planner, together with an efficient local path planner. We describe the basic concepts of our algorithm and investigate some details of the local planner.
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