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Xiaoming Li

Publications and source records attributed to Xiaoming Li.

92 records · Page 6Linked to original sources

On the length of Golomb Ruler: A function construction approach based on difference triangle

Since the significance of Golomb Ruler Problem in some context, we proposes a function construction approach based on difference triangle to generate near-optimal Golomb rulers. Let x1, x2, ..., xn be an increasing sequence of integers, where x1 = 0, which satisfies the following conditions: if abs(xi-xj) = abs(xp-xq) then {i, j} = {p,q}. Our objective is to find the order of minimum xn for any given n. In this paper, the two results in a paper are both improved. In addition, it will be shown that the length of Golomb Ruler have been shortened to a half, and that the satisfying sequence can not be generated by such a quadratic formula as $xi = ai^2+bni+ci+dn^2+en+f$ for any rational a, b, c, d, e and f.

math.NT↗

A commend on "Three Classes of Newtonian Three-Body Planar Periodic Orbits" by Šuvakov and Dmitrašinović (PRL, 2013)

Currently, the fifteen new periodic solutions of Newtonian three-body problem with equal mass were reported by Šuvakov and Dmitrašinović (PRL, 2013) [1]. However, using a reliable numerical approach (namely the Clean Numerical Simulation, CNS) that is based on the arbitrary-order Taylor series method and data in arbitrary-digit precision, it is found that at least seven of them greatly depart from the periodic orbits after a long enough interval of time. Therefore, the reported initial conditions of at least seven of the fifteen orbits reported by Šuvakov and Dmitrašinović [1] are not accurate enough to predict periodic orbits. Besides, it is found that these seven orbits are unstable.

astro-ph.EP↗