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6.0

Jun 30, 2018
06/18

by
Akitoshi Kawamura; Yusuke Kobayashi

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Suppose we want to patrol a fence (line segment) using k mobile agents with given speeds v_1, ..., v_k so that every point on the fence is visited by an agent at least once in every unit time period. Czyzowicz et al. conjectured that the maximum length of the fence that can be patrolled is (v_1 + ... + v_k)/2, which is achieved by the simple strategy where each agent i moves back and forth in a segment of length v_i/2. We disprove this conjecture by a counterexample involving k = 6 agents. We...

Topics: Multiagent Systems, Computing Research Repository, Computational Geometry, Robotics

Source: http://arxiv.org/abs/1407.8194

7
7.0

Jun 30, 2018
06/18

by
Alejandro Edera; Yanela Strappa; Facundo Bromberg

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Markov networks are models for compactly representing complex probability distributions. They are composed by a structure and a set of numerical weights. The structure qualitatively describes independences in the distribution, which can be exploited to factorize the distribution into a set of compact functions. A key application for learning structures from data is to automatically discover knowledge. In practice, structure learning algorithms focused on "knowledge discovery" present...

Topics: Computing Research Repository, Data Structures and Algorithms, Learning

Source: http://arxiv.org/abs/1407.8088

6
6.0

Jun 30, 2018
06/18

by
L. Amati; J. Braga; F. Frontera; C. Labanti; M. Feroci; R. Hudec; A. Gomboc; R. Ruffini; A. Santangelo; A. Vacchi; R. Campana; Y. Evangelista; F. Fuschino; R. Salvaterra; G. Stratta; G. Tagliaferri; C. Guidorzi; P. Rosati; L. Titarchuk; A. Penacchioni; L. Izzo; N. Zampa; T. Rodic; on behalf of the GAME collaboration

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We describe the GRB and All-sky Monitor Experiment (GAME) mission submitted by a large international collaboration (Italy, Germany, Czech Repubblic, Slovenia, Brazil) in response to the 2012 ESA call for a small mission opportunity for a launch in 2017 and presently under further investigation for subsequent opportunities. The general scientific objective is to perform measurements of key importance for GRB science and to provide the wide astrophysical community of an advanced X-ray all-sky...

Topics: Instrumentation and Methods for Astrophysics, High Energy Astrophysical Phenomena, Astrophysics

Source: http://arxiv.org/abs/1407.8126

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8.0

Jun 30, 2018
06/18

by
Richard Baraniuk; Simon Foucart; Deanna Needell; Yaniv Plan; Mary Wootters

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Binary measurements arise naturally in a variety of statistical and engineering applications. They may be inherent to the problem---e.g., in determining the relationship between genetics and the presence or absence of a disease---or they may be a result of extreme quantization. In one-bit compressed sensing it has recently been shown that the number of one-bit measurements required for signal estimation mirrors that of unquantized compressed sensing. Indeed, $s$-sparse signals in $\mathbb{R}^n$...

Topics: Mathematics, Computing Research Repository, Information Theory, Statistics Theory, Statistics

Source: http://arxiv.org/abs/1407.8246

5
5.0

Jun 30, 2018
06/18

by
S. Ehlert; S. W. Allen; W. N. Brandt; R. E. A. Canning; B. Luo; A. Mantz; R. G. Morris; A. von der Linden; Y. Q. Xue

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We present the results of a new analysis of the X-ray selected Active Galactic Nuclei (AGN) population in the vicinity of 135 of the most massive galaxy clusters in the redshift range of 0.2 < z < 0.9 observed with Chandra. With a sample of more than 11,000 X-ray point sources, we are able to measure, for the first time, evidence for evolution in the cluster AGN population beyond the expected evolution of field AGN. Our analysis shows that overall number density of cluster AGN scales with...

Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics

Source: http://arxiv.org/abs/1407.8181

6
6.0

Jun 30, 2018
06/18

by
Yiran Wang; R. J. Brunner

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We analyze the clustering of photometrically selected galaxy pairs by using the halo-occupation distribution (HOD) model. We measure the angular two-point auto-correlation function, $\omega(\theta)$, for galaxies and galaxy pairs in three volume-limited samples and develop an HOD to model their clustering. Our results are successfully fit by these HOD models, and we see the separation of "1-halo" and "2-halo" clustering terms for both single galaxies and galaxy pairs. Our...

Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics

Source: http://arxiv.org/abs/1407.8230

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Jun 30, 2018
06/18

by
Yixuan Xie; Jinhong Yuan; Qifu; Sun

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We propose two types, namely Type-I and Type-II, quantum stabilizer codes using quadratic residue sets of prime modulus given by the form $p=4n\pm1$. The proposed Type-I stabilizer codes are of cyclic structure and code length $N=p$. They are constructed based on multi-weight circulant matrix generated from idempotent polynomial, which is obtained from a quadratic residue set. The proposed Type-II stabilizer codes are of quasi-cyclic (QC) structure and code length $N=pk$, where $k$ is the size...

Topics: Mathematics, Computing Research Repository, Information Theory

Source: http://arxiv.org/abs/1407.8249

8
8.0

Jun 30, 2018
06/18

by
Yuan Zhu; Siyun Tang

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In this paper, a new algebraic soft-decision decoding algorithm for Reed-Solomon code is presented. It is based on rational interpolation and the interpolation points are constructed by Berlekamp-Messay algorithm. Unlike the traditional K{\"o}tter-Vardy algorithm, new algorithm needs interpolation for two smaller multiplicity matrixes, due to the corresponding factorization algorithm for re-constructing codewords.

Topics: Mathematics, Computing Research Repository, Information Theory

Source: http://arxiv.org/abs/1407.8069

5
5.0

Jun 30, 2018
06/18

by
Yun-Fei Yang; Hui-Xue Qu; Kai-Fan Ji; Song Feng; Hui Deng; Jia-Ben Lin; Feng Wang

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We study the motions of G band bright points (GBPs) in the quiet Sun to obtain the characteristics of different motion types. A high resolution image sequence taken with the Hinode/Solar Optical Telescope (SOT) is used, and GBPs are automatically tracked by segmenting 3D evolutional structures in a space time cube. After putting the GBPs that do not move during their lifetimes aside, the non stationary GBPs are categorized into three types based on an index of motion type. Most GBPs that move...

Topics: Astrophysics, Solar and Stellar Astrophysics

Source: http://arxiv.org/abs/1407.7958