Lyman-Break Galaxy (LBG) samples observed during reionization (z 6) with Hubble Space Telescope's WideFieldCamera3 are reaching sizes sufficient to characterize their clustering properties. Using a combined catalog from the Hubble eXtreme Deep Field and CANDELS surveys, containing N = 743 LBG candidates at z ≥ 6.5 at a mean redshift of z = 7.2, we detect a clear clustering signal in the angular correlation function (ACF) at 4σ, corresponding to a real-space correlation length r 0 = 6.7 +0.9 −1.0 h −1 cMpc. The derived galaxy bias b = 8.6 +0.9 −1.0 is that of dark-matter halos of M = 10 11.1 +0.2 −0.3 M at z = 7.2, and highlights that galaxies below the current detection limit (M AB ∼ −17.7) are expected in lower-mass halos (M ∼ 10 8 − 10 10.5 M ). We compute the ACF of LBGs at z ∼ 3.8 − z ∼ 5.9 in the same surveys. A trend of increasing bias is found from z = 3.8 (b ∼ 3.0) to z = 7.2 (b ∼ 8.6), broadly consistent with galaxies at fixed luminosity being hosted in dark-matter halos of similar mass at 4 z 6, followed by a slight rise in halo masses at z 7 (∼ 2σ confidence). Separating the data at the median luminosity of the z = 7.2 sample (M U V = −19.4) shows higher clustering at z = 5.9 for bright galaxies (r 0 = 5.5 +1.4 −1.6 h −1 cMpc, b = 6.2 +1.2 −1.5 ) compared to faint galaxies (r 0 = 1.9 +1.1 −1.0 h −1 cMpc, b = 2.7 +1.2 −1.2 ) implying a constant mass-to-light ratio dlogM dlogL ∼ 1.2 +1.8 −0.8 . A similar trend is present in the z = 7.2 sample with larger uncertainty. Finally, our bias measurements allow us to investigate the fraction of dark-matter halos hosting UV-bright galaxies (the duty-cycle, DC ). At z = 7.2 values near unity are preferred, which may be explained by the shortened halo assembly time at high-redshift.

We study the bivariate size-luminosity distribution of Lyman Break Galaxies (LBGs) selected at redshifts around 4 and 5 in GOODS and the HUDF fields. We model the size-luminosity distribution as a combination of log-normal distribution (in size) and Schechter function (in luminosity), therefore it enables a more detailed study of the selection effects. We perform extensive simulations to quantify the dropout-selection completenesses and measurement biases and uncertainties in two-dimensional size and magnitude bins, and transform the theoretical size-luminosity distribution to the expected distribution for the observed data. Using maximum-likelihood estimator (MLE), we find that the Schechter function parameters for B 435 -dropouts are α = −1.68 +0.068 −0.095 , M * = −20.60 +0.13 −0.17 , and φ * = 1.79 +0.32 −0.52 ×10 −3 Mpc −3 . The log-normal size distribution is characterized by the peak R 0 = 1.34 +0.099 −0.108 kpc at M 1500 = −21 mag, width σ ln R = 0.83 +0.046 −0.044 , and the slope of the size-luminosity (RL) relation β = 0.22 +0.058 −0.056 . Similarly, for V 606 -dropouts we find α = −1.74 +0.15 −0.20 , M * = −20.53 +0.24 −0.27 , φ * = 1.55 +0.62 −0.77 × 10 −3 Mpc −3 , R 0 = 1.19 +0.21 −0.16 kpc, σ ln R = 0.90 +0.15 −0.065 , and β = 0.25 +0.15 −0.14 . The Schechter function parameters are consistent with the values in the literature, while the size distributions are wider than expected from the angular momentum distribution of the underlying dark matter halos.The slope of the size-luminosity (RL) relation is similar to those found for local disk galaxies, but considerably shallower than local early-type galaxies.

No abstract

No abstract

Fast splitting based tag identification algorithm for anti-collision in UHF RFID System. IEEE Transactions on Communications.

No abstract

No abstract

Guangjun (2016) An effective frame breaking policy for dynamic framed slotted aloha in RFID. IEEE Communications Letters, 20 (4). pp. 692-695. ISSN 1089-7798 This version is available from Sussex Research Online: http://sro.sussex.ac.uk/59314/ This document is made available in accordance with publisher policies and may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the URL above for details on accessing the published version. Copyright and reuse:Sussex Research Online is a digital repository of the research output of the University.Copyright and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable, the material made available in SRO has been checked for eligibility before being made available.Copies of full text items generally can be reproduced, displayed or performed and given to third parties in any format or medium for personal research or study, educational, or not-for-profit purposes without prior permission or charge, provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Abstract-Tag collision problem is considered as one of the critical issues in RFID system. To further improve the identification efficiency of UHF RFID system, a frame breaking policy is proposed with dynamic framed slotted aloha algorithm. Specifically, the reader makes effective use of idle, successful and collision statistics during the early observation phase to recursively determine the optimal frame size. Then the collided tags in each slot will be resolved by individual frames. Simulation results show that the proposed algorithm achieves a better identification performance compared with the existing Alohabased algorithms.