10,055 research outputs found
Luminosity Dependent Evolution of Lyman Break Galaxies from redshift 5 to 3
In this contribution we briefly describe our recent results on the properties
of Lyman break galaxies at z~5 obtained from deep and wide blank field surveys
using Subaru telescope, and through the comparison with samples at lower
redshift ranges we discuss the evolution of star-forming galaxies in the early
universe.Comment: 2 pages, 1 figure, for the proceedings of the IAU Symposium 235,
Galaxies Across the Hubble Time, J. Palous & F. Combes, ed
Non-ergodic transitions in many-body Langevin systems: a method of dynamical system reduction
We study a non-ergodic transition in a many-body Langevin system. We first
derive an equation for the two-point time correlation function of density
fluctuations, ignoring the contributions of the third- and fourth-order
cumulants. For this equation, with the average density fixed, we find that
there is a critical temperature at which the qualitative nature of the
trajectories around the trivial solution changes. Using a method of dynamical
system reduction around the critical temperature, we simplify the equation for
the time correlation function into a two-dimensional ordinary differential
equation. Analyzing this differential equation, we demonstrate that a
non-ergodic transition occurs at some temperature slightly higher than the
critical temperature.Comment: 8 pages, 1 figure; ver.3: Calculation errors have been fixe
Fine-Grained Complexity of k-OPT in Bounded-Degree Graphs for Solving TSP
The Traveling Salesman Problem asks to find a minimum-weight Hamiltonian cycle in an edge-weighted complete graph. Local search is a widely-employed strategy for finding good solutions to TSP. A popular neighborhood operator for local search is k-opt, which turns a Hamiltonian cycle C into a new Hamiltonian cycle C\u27 by replacing k edges. We analyze the problem of determining whether the weight of a given cycle can be decreased by a k-opt move. Earlier work has shown that (i) assuming the Exponential Time Hypothesis, there is no algorithm that can detect whether or not a given Hamiltonian cycle C in an n-vertex input can be improved by a k-opt move in time f(k) n^o(k / log k) for any function f, while (ii) it is possible to improve on the brute-force running time of O(n^k) and save linear factors in the exponent. Modern TSP heuristics are very successful at identifying the most promising edges to be used in k-opt moves, and experiments show that very good global solutions can already be reached using only the top-O(1) most promising edges incident to each vertex. This leads to the following question: can improving k-opt moves be found efficiently in graphs of bounded degree? We answer this question in various regimes, presenting new algorithms and conditional lower bounds. We show that the aforementioned ETH lower bound also holds for graphs of maximum degree three, but that in bounded-degree graphs the best improving k-move can be found in time O(n^((23/135+epsilon_k)k)), where lim_{k -> infty} epsilon_k = 0. This improves upon the best-known bounds for general graphs. Due to its practical importance, we devote special attention to the range of k in which improving k-moves in bounded-degree graphs can be found in quasi-linear time. For k <= 7, we give quasi-linear time algorithms for general weights. For k=8 we obtain a quasi-linear time algorithm when the weights are bounded by O(polylog n). On the other hand, based on established fine-grained complexity hypotheses about the impossibility of detecting a triangle in edge-linear time, we prove that the k = 9 case does not admit quasi-linear time algorithms. Hence we fully characterize the values of k for which quasi-linear time algorithms exist for polylogarithmic weights on bounded-degree graphs
A new method of alpha ray measurement using a Quadrupole Mass Spectrometer
We propose a new method of alpha()-ray measurement that detects
helium atoms with a Quadrupole Mass Spectrometer(QMS). A demonstration is
undertaken with a plastic-covered Am -emitting source to detect
-rays stopped in the capsule. We successfully detect helium atoms that
diffuse out of the capsule by accumulating them for one to 20 hours in a closed
chamber. The detected amount is found to be proportional to the accumulation
time. Our method is applicable to probe -emitting radioactivity in bulk
material.Comment: 8 pages, 6 figure
Assembling strategies in extrinsic evolvable hardware with bi-directional incremental evolution
Bidirectional incremental evolution (BIE) has been proposed as a technique to overcome the âstallingâ effect in evolvable hardware applications. However preliminary results show perceptible dependence of performance of BIE and quality of evaluated circuit on assembling strategy applied during reverse stage of incremental evolution. The purpose of this paper is to develop assembling strategy that will assist BIE to produce relatively optimal solution with minimal computational effort (e.g. the minimal number of generations)
Can Increasing Fruit and Vegetable Intake Decrease High Blood Pressure?
High blood pressure is usually treated through pharmaceutics medications but research suggests that blood pressure may also be managed through changes in diet through an increase in fruit and vegetable consumption.https://dune.une.edu/an_studedres/1153/thumbnail.jp
Ingredients of nuclear matrix element for two-neutrino double-beta decay of 48Ca
Large-scale shell model calculations including two major shells are carried
out, and the ingredients of nuclear matrix element for two-neutrino double beta
decay are investigated. Based on the comparison between the shell model
calculations accounting only for one major shell (-shell) and those for two
major shells (-shell), the effect due to the excitation across the two
major shells is quantitatively evaluated.Comment: To appear in J. Phys. Soc. Conf. Proc. (ARIS2014); for ver.2, Fig.1
is revise
The Japanese Payloads for the N-Launch Vehicles
National Space Development Agency of Japan (NASDA), which was established in 1969 as the nucleus of the national space development effort, is promoting a variety of space projects in accordance with the Space Development Programs which are decided and revised annually by the Space Activities Commission in line with the basic space development plan authorized by the Prime Minister.
Since 1975, NASDA has launched the following satellites from Tanegashima Space Center: ETS-I (KIKU), ETS-II (KIKU-2), ISS-a (UME), ISS-b (UME-2), ECS-a (AYAME), ECS-b (AYAME-2), ETS-IV (KIKU-3) and GMS-2 (HIMAWARI-2). The launch vehicles for these satellites are the N-I and the N-II launch vehicles, of which outline has been presented last year at this congress
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