Glass Beads in Iron-Age and Early-Modern Taiwan: An Introduction

Archaeological research has revealed a long history of glass bead exchange and use in Taiwan, yet it has seldom been discussed in the literature. This paper provides an introduction to this exchange from the Iron Age (ca. late 1st millennium BC – mid-2nd millennium AD) to the early modern period (ca. AD 1600-1900) by revisiting the archaeological and historical records. It is suggested that changes in bead styles and chemical compositions over time reveal the transition of bead supply in Taiwan, which further reflects two broad phases of bead trade: Phase I) the earlier involvement of Taiwan in the Indo-Pacific bead exchange (1st millennium AD) and Phase II) the later cultural and economic contacts between the indigenous people, Chinese merchants, and Europeans (2nd millennium AD)

A REVIEW OF GLASS COMPOSITIONS AROUND THE SOUTH CHINA SEA REGION (THE LATE 1ST MILLENNIUM BC TO THE 1ST MILLENNIUM AD): PLACING IRON AGE GLASS BEADS FROM TAIWAN IN CONTEXT

With more published chemical analyses of glass beads in Southeast Asia and southern China in the last decade, it is becoming possible to discuss the regional and temporal patterns of prehistoric glass beads in these areas. This article focuses the 1st millennium AD, reviewing the chemical composition of glass in Taiwan, Southeast Asia and southern China, in an attempt to understand the potential relationships between the three regions

Dynamics of Rapidly Rotating Bose-Einstein Quantum Droplets

The work theoretically investigates the dynamics of trapped rapidly rotating Bose-Einstein droplets governed by the modified Gross-Pitaevskii equation with the inclusion of Lee-Huang-Yang nonlinear interaction. Mimicking the quantum Hall systems, the stationary properties of droplets are obtained by minimizing the energy functional established based on the Laughlin-like wavefunction including Landau-Level mixing. By tuning the particle-particle interaction and rotation speed, the preference of the formation of the center-of-mass state, vortex state, and off-centered vortex state can be distinguished on the phase diagram. Under fast rotations, the highly-spiral phase portraits reveal that the emergence of huge vortices with high angular momentum would stabilize the droplets against centrifugal depletion. By solving Euler-Lagrange equations, the periodicity and stability of each phase's breathing and trajectory during long-time evolution are analyzed. As a signature of superfluids, the generation of nonuniform persistent currents of multiple topological charges is also a direct reflection of dynamic breathing induced by the Landau-Level mixing effect

Design of Dynamic Frequency Divider Using Negative Differential Resistance Circuit

The behavior of two frequency divider circuits using negative differential resistance (NDR) circuit is studied. This NDR circuit is made of three resistors (R) and two bipolar-junction-transistor (BJT) devices. It can show the NDR characteristic in its current-voltage curve by suitably designing the resistances. We discuss a dynamic frequency divider, which is made of a R-BJT-NDR circuit, an inductor, and a capacitor. This frequency divider circuit is based on the long-period behavior of the nonlinear NDR circuits generating chaos. It demonstrates the period-adding sequences which appear in its bifurcation diagram to perform the frequency division. We investigate the effects of the input signal frequency on the operation. The results show that the dividing ratio can be selected by changing the input frequency. We also discuss the effect of inputting different types of signals with the same frequency on the operation of this frequency divider. The results show that the input signal distortion has a negligible influence on the frequency divider state. DOI: 10.17762/ijritcc2321-8169.15083

Stationary Light Pulses in Cold Atomic Media

Stationary light pulses (SLPs), i.e., light pulses without motion, are formed via the retrieval of stored probe pulses with two counter-propagating coupling fields. We show that there exist non-negligible hybrid Raman excitations in media of cold atoms that prohibit the SLP formation. We experimentally demonstrate a method to suppress these Raman excitations and realize SLPs in laser-cooled atoms. Our work opens the way to SLP studies in cold as well as in stationary atoms and provides a new avenue to low-light-level nonlinear optics.Comment: 4 pages, 4 figure

Parameter inference for coalescing massive black hole binaries using deep learning

In the 2030s, a new era of gravitational-wave (GW) observations will dawn as multiple space-based GW detectors, such as the Laser Interferometer Space Antenna, Taiji and TianQin, open the millihertz window for GW astronomy. These detectors are poised to detect a multitude of GW signals emitted by different sources. It is a challenging task for GW data analysis to recover the parameters of these sources at a low computational cost. Generally, the matched filtering approach entails exploring an extensive parameter space for all resolvable sources, incurring a substantial cost owing to the generation of GW waveform templates. To alleviate the challenge, we make an attempt to perform parameter inference for coalescing massive black hole binaries (MBHBs) using deep learning. The model trained in this work has the capability to produce 50,000 posterior samples for redshifted total mass, mass ratio, coalescence time and luminosity distance of a MBHB in about twenty seconds. Our model can serve as a potent data pre-processing tool, reducing the volume of parameter space by more than four orders of magnitude for MBHB signals with a signal-to-noise ratio larger than 100. Moreover, the model exhibits robustness when handling input data that contains multiple MBHB signals.Comment: 8 pages, 4 figure

Somatomotor-Visual Resting State Functional Connectivity Increases After Two Years in the UK Biobank Longitudinal Cohort

Functional magnetic resonance imaging (fMRI) and functional connectivity (FC) have been used to follow aging in both children and older adults. Robust changes have been observed in children, where high connectivity among all brain regions changes to a more modular structure with maturation. In older adults, prior work has identified changes in connectivity associated with the default mode network (DMN); other work has used brain age to predict pre-clinical Alzheimer's disease. In this work, we find an increasing connectivity between the Somatomotor (SMT) and Visual (VIS) Networks using the Power264 atlas in a longitudinal cohort of the UK Biobank (UKB). This cohort consists of 2,722 subjects, with scans being taken an average of two years apart. The average connectivity increase between SMT-VIS is 6.8% compared to the younger scan baseline (from $\rho=0.39$ to $\rho=0.42$), and occurs in male, female, older subject ($>65$ years old), and younger subject ($<55$ years old) groups. Among all inter-network connections, this average SMT-VIS connectivity is the best predictor of relative scan age, accurately predicting which scan is older 57% of the time. Using the full FC and a training set of 2,000 subjects, one is able to predict which scan is older 82.5% of the time when using the difference of FC between the two scans as input to a classifier. This previously under-reported relationship may shed light on normal changes in aging brain FC, identifies a potential confound for longitudinal studies, and proposes a new area for investigation, specifically the SMT-VIS connectivity.Comment: 12 pages, 10 figures, 3 table