Numerical Study on Indoor Wideband Channel Characteristics with Different Internal Wall

Effects of material and configuration of the internal wall on the performance of wideband channel are investigated by using the Finite Difference Time-Domain (FDTD) method. The indoor wideband channel characteristics, such as the path-loss, Root-Mean-Square (RMS) delay spread and number of the multipath components (MPCs), are presented. The simulated results demonstrate that the path-loss and MPCs are affected by the permittivity, dielectric loss tangent and thickness of the internal wall, while the RMS delay spread is almost not relevant with the dielectric permittivity. Furthermore, the comparison of simulated result with the measured one in a simple scenario has validated the simulation study

Constrained structure of ancient Chinese poetry facilitates speech content grouping

Ancient Chinese poetry is constituted by structured language that deviates from ordinary language usage [1, 2]; its poetic genres impose unique combinatory constraints on linguistic elements [3]. How does the constrained poetic structure facilitate speech segmentation when common linguistic [4, 5, 6, 7, 8] and statistical cues [5, 9] are unreliable to listeners in poems? We generated artificial Jueju, which arguably has the most constrained structure in ancient Chinese poetry, and presented each poem twice as an isochronous sequence of syllables to native Mandarin speakers while conducting magnetoencephalography (MEG) recording. We found that listeners deployed their prior knowledge of Jueju to build the line structure and to establish the conceptual flow of Jueju. Unprecedentedly, we found a phase precession phenomenon indicating predictive processes of speech segmentation—the neural phase advanced faster after listeners acquired knowledge of incoming speech. The statistical co-occurrence of monosyllabic words in Jueju negatively correlated with speech segmentation, which provides an alternative perspective on how statistical cues facilitate speech segmentation. Our findings suggest that constrained poetic structures serve as a temporal map for listeners to group speech contents and to predict incoming speech signals. Listeners can parse speech streams by using not only grammatical and statistical cues but also their prior knowledge of the form of language

Deep Learning for Single Image Super-Resolution: A Brief Review

Single image super-resolution (SISR) is a notoriously challenging ill-posed problem, which aims to obtain a high-resolution (HR) output from one of its low-resolution (LR) versions. To solve the SISR problem, recently powerful deep learning algorithms have been employed and achieved the state-of-the-art performance. In this survey, we review representative deep learning-based SISR methods, and group them into two categories according to their major contributions to two essential aspects of SISR: the exploration of efficient neural network architectures for SISR, and the development of effective optimization objectives for deep SISR learning. For each category, a baseline is firstly established and several critical limitations of the baseline are summarized. Then representative works on overcoming these limitations are presented based on their original contents as well as our critical understandings and analyses, and relevant comparisons are conducted from a variety of perspectives. Finally we conclude this review with some vital current challenges and future trends in SISR leveraging deep learning algorithms.Comment: Accepted by IEEE Transactions on Multimedia (TMM

Observation of indirect ionization of W7+ in an electron-beam ion-trap plasma

In this work, visible and extreme ultraviolet spectra of W7+ are measured using the high-temperature superconducting electron-beam ion trap (EBIT) at the Shanghai EBIT Laboratory under extremely low-energy conditions (lower than the nominal electron-beam energy of 130 eV). The relevant atomic structure is calculated using the flexible atomic code package based on the relativistic configuration interaction method. The GRASP2K code, in the framework of the multiconfiguration Dirac-Hartree-Fock method, is employed as well for calculating the wavelength of the M1 transition in the ground configuration of W7+. A line from the W7+ ions is observed at a little higher electron-beam energy than the ionization potential for W4+, making this line appear to be from W5+. A hypothesis for the charge-state evolution of W7+ is proposed based on our experimental and theoretical results; that is, the occurrence of W7+ ions results from indirect ionization caused by stepwise excitation between some metastable states of lower-charge-state W ions, at the nominal electron-beam energy of 59 eV

In situ loading and delivery of short single- And double-stranded dna by supramolecular organic frameworks

Short DNA represents an important class of biomacromolecules that are widely applied in gene therapy, editing, and modulation. However, the development of simple and reliable methods for their intracellular delivery remains a challenge. Herein, we describe that seven water-soluble, homogeneous supramolecular organic frameworks (SOFs) with a well-defined pore size and high stability in water that can accomplish in situ inclusion of single-stranded (ss) and double-stranded (ds) DNA (21, 23, and 58 nt) and effective intracellular delivery (including two noncancerous and six cancerous cell lines). Fluorescence quenching experiments for single and double endlabeled ss- and ds-DNA support that the DNA sequences can be completely enveloped by the SOFs. Confocal laser scanning microscopy and flow cytometry reveal that five of the SOFs exhibit excellent delivery efficiencies that, in most of the studied cases, outperform the commercial standard Lipo2000, even at low SOF-nucleic acid ratios. In addition to high delivery efficiencies, the watersoluble, self-assembled SOF carriers have a variety of advantages, including convenient preparation, high stability, and in situ DNA inclusion, which are all critical for practical applications in nucleic acid delivery

SSL++: Improving Self-supervised Learning by Mitigating the Proxy Task-Specificity Problem

The success of deep convolutional networks (ConvNets) generally relies on a massive amount of well-labeled data, which is labor-intensive and time-consuming to collect and annotate in many scenarios. To eliminate such limitation, self-supervised learning (SSL) is recently proposed. Specifically, by solving a pre-designed proxy task, SSL is capable of capturing general-purpose features without requiring human supervision. Existing efforts focus obsessively on designing a particular proxy task but ignore the semanticity of samples that are advantageous to downstream tasks, resulting in the inherent limitation that the learned features are specific to the proxy task, namely the proxy task-specificity of features. In this work, to improve the generalizability of features learned by existing SSL methods, we present a novel self-supervised framework SSL++ to incorporate the proxy task-independent semanticity of samples into the representation learning process. Technically, SSL++ aims to leverage the complementarity, between the low-level generic features learned by a proxy task and the high-level semantic features newly learned by the generated semantic pseudo-labels, to mitigate the task-specificity and improve the generalizability of features. Extensive experiments show that SSL++ performs favorably against the state-of-the-art approaches on the established and latest SSL benchmarks. The code will be available to the public

Effects of vitrification and post-thawing interval on the cytoskeleton and subsequent fertilization rate of in vitro derived bovine oocytes

Vitrification may alter the cytoskeleton (microtubule, meiotic spindle, microfilament, etc.) and the subsequent fertilization rate of in vitro derived bovine oocytes. This study was conducted to evaluate the effect of vitrification and post-thawing incubation periods on the cytoskeleton and fertilization rate of in vitro matured (IVM) bovine oocytes. Following 22 h of IVM, 184 fresh matured oocytes (MO) were immediately fertilized in vitro and served as a control. The remaining MO (1009) were then vitrified by the solid surface vitrification method. Immediately after thawing, MO were incubated in maturation medium in 5% CO2 at 39 °C for 0, 30, 60, 90 and 120 min respectively. Following incubation, half of the MO from each vitrified-thawed treatment group (0, 30, 60, 90, and 120 min) was stained with fluorescein isothiocyanate conjugated (FITC) and propidium iodide (PI) to evaluate the microtubule and DNA or spindle under laser-scanning confocal microscopy. The remaining half from the vitrified-thawed MO treatment groups was washed three times in Brackett and Oliphant\'s fertilization medium and in vitro fertilized. Cleavage and blastocyst rates were recorded 48 h post-fertilization. Results demonstrated that vitrification damaged MO zona pellucida (ZP), microtubule (MT), meiotic spindle (MS), and caused chromosomal fragmentation. Both the cleavage (84%) and blastocyst rates (50%) of the control group were significantly higher compared to the vitrified-thawed treatment groups. However, extending the incubation period of vitrified MO to 120 min after thawing (prior to fertilization) improved cleavage (65%) and blastocyst (13%) rates 48 h post-fertilization. Fertilizing vitrified MO immediately (0 min group) after thawing resulted in the lowest cleavage (42%) and blastocyst (1.9%) rates. In conclusion, vitrification reduces the subsequent fertilization rate of MO, however, a prolonged post-thawing incubation period (120 min) improves survival, cleavage and blastocyst formation rates, and enhances the reorganization of MO\'s cytoskeleton (MT and MS). Keywords: Vitrification; cytoskeleton; bovine; oocytes; fertilization; in vitro matured South African Journal of Animal Science Vol. 36 (5) 2006: pp.42-4