Spatial Statistical Models: An Overview under the Bayesian Approach

Spatial documentation is exponentially increasing given the availability of Big Data in the Internet of Things, enabled by device miniaturization and data storage capacity. Bayesian spatial statistics is a useful statistical tool to determine the dependence structure and hidden patterns in space through prior knowledge and data likelihood. However, this class of modeling is not yet well explored when compared to adopting classification and regression in machine-learning models, in which the assumption of the spatiotemporal independence of the data is often made, that is an inexistent or very weak dependence. Thus, this systematic review aims to address the main models presented in the literature over the past 20 years, identifying the gaps and research opportunities. Elements such as random fields, spatial domains, prior specification, the covariance function, and numerical approximations are discussed. This work explores the two subclasses of spatial smoothing: global and local.

High-Performance Photodetectors Based on Nanostructured Perovskites

In recent years, high-performance photodetectors have attracted wide attention because of their important applications including imaging, spectroscopy, fiber-optic communications, remote control, chemical/biological sensing and so on. Nanostructured perovskites are extremely suitable for detective applications with their long carrier lifetime, high carrier mobility, facile synthesis, and beneficial to device miniaturization. Because the structure of the device and the dimension of nanostructured perovskite have a profound impact on the performance of photodetector, we divide nanostructured perovskite into 2D, 1D, and 0D, and review their applications in photodetector (including photoconductor, phototransistor, and photodiode), respectively. The devices exhibit high performance with high photoresponsivity, large external quantum efficiency (EQE), large gain, high detectivity, and fast response time. The intriguing properties suggest that nanostructured perovskites have a great potential in photodetection.

Persistent Josephson Phase-Slip Memory with Topological Protection

Superconducting computing promises enhanced computational power in both classical and quantum approaches. Yet, efficient schemes for scalable and fast superconducting memories are still missing. On the one hand, the large inductance required in magnetic flux-controlled Josephson memories impedes device miniaturization and scalability. On the other hand, schemes based on the ferromagnetic order to store information often degrades superconductivity, and limits the operation speed to the magnetization switching rate of a few GHz. Here, we overcome these limitations with a fully superconducting memory cell based on the hysteretic phase-slip transition existing in long aluminum nanowire Josephson junctions. The memory logic state is codified in the topological index of the junction providing a robust protection against stocastic phase slips and magnetic flux noise. Our direct and non-destructive read-out schemes, based on local DC or AC tunneling spectroscopy, ensure reduced dissipation (≤ 40 fW) thereby yielding a very low energy per bit read-out power consumption as low as ~ 10-24 J as estimated from the typical time response of the structure (≤ 30 ps). The memory, measured over several days, showed no evidence of information degradation up to ~1.1 K, i.e., ~85% of the critical temperature of aluminum. The ease of operation combined with remarkable performance elects the Josephson phase-slip memory as an attractive storage cell to be exploited in advanced superconducting classical logic architectures or flux qubits.

Cross-nanofin-based waveplate pixels for broadband hybrid polarization coding in near-field

As an inherent characteristic of light, polarization plays important roles in information storage, display and even encryption. Metasurfaces, composed of specifically designed subwavelength units in a two-dimensional plane, offer a great convenience for polarization manipulation, yet improving their integrability and broadband fidelity remain significant challenges. Here, based on the combination of various subwavelength cross-nanofins (CNs), a new type of metasurface for multichannel hybrid polarization distribution in near-field is proposed. Sub-wavelength CN units with various waveplate (WP) functionalities, such as frequency-division multiplexing WP, half-WP and quarter-WP are implemented with high efficiency in broadband. High-resolution grayscale image encryption, multi-image storage and rapid polarization detection are demonstrated by encoding the WP pixels into single, double and four channels, respectively. All these applications possess good fidelity in an ultrabroad wavelength band from 1.2 to 1.9 µm, and the high degree of integrability, easy fabrication and multifunction make the CN-shaped WP pixels a promising candidate in optical device miniaturization, quantum applications and imaging technologies.

NFC-Based Wearable Optoelectronics Working with Smartphone Application for Untact Healthcare

With growing interest in healthcare, wearable healthcare devices have been developed and researched. In particular, near-field communication (NFC) based wearable devices have been actively studied for device miniaturization. Herein, this article proposes a low-cost and convenient healthcare system, which can monitor heart rate and temperature using a wireless/battery-free sensor and the customized smartphone application. The authors designed and fabricated a customized healthcare device based on the NFC system, and developed a smartphone application for real-time data acquisition and processing. In order to achieve compact size without performance degradation, a dual-layered layout is applied to the device. The authors demonstrate that the device can operate as attached on various body sites such as wrist, fingertip, temple, and neck due to outstanding flexibility of device and adhesive strength between the device and the skin. In addition, the data processing flow and processing result are presented for offering heart rate and skin temperature. Therefore, this work provides an affordable and practical pathway for the popularization of wireless wearable healthcare system. Moreover, the proposed platform can easily delivery the measured health information to experts for contactless/personal health consultation.

Abstract 16097: Impact of Device Miniaturization on Implantable Loop Recorder Utilization in the Pediatric Population: An Analysis of the Marketscan Database

Introduction: Implantable loop recorders (ILRs) are an effective technology in the detection of paroxysmal arrhythmias, but utility in the pediatric population has been limited by device size. In 2014, a miniaturized ILR was introduced with a less invasive implant technique. The impact of this technology on ILR utilization in pediatric patients has not been evaluated. Hypothesis: We hypothesize an increase in annual pediatric ILR implants since 2014 due to device miniaturization. Methods: A retrospective observational study was conducted using administrative claims from Marketscan Medicaid and Commercial insurance claims databases. Utilization of ILR between 1/2013 and 12/2018 was measured (normalized to the total enrolled population ≤18 years) and compared to two balancing measures (Holter ambulatory monitors and encounters with syncope as a diagnosis). Secondary analyses included evaluations of subsequent interventions and complications. Results: The study cohort included 33,532,185 individual subjects, of which 769 underwent ILR implantation. ILR subjects were 52% male, with a median age of 16 years (IQR 10-17 yrs). 71% had a history of syncope, 43% had a history of palpitations, and 28% had a history of congenital heart disease. Utilization of ILR increased in 2014, from 5 procedures per million enrollees in 2013 to 11 per million between 2015-2018, while balancing measures remained static (see Figure).Of 393 subjects with ≥1 year of follow-up post-implant, interventions included catheter ablation in 24 (6%), pacemaker implant in 15 (4%) and ICD implant in 7 (1.8%). Among this group, 14 (3.6%) had a device infection and 5 (1.3%) had an erosion. Conclusions: Following introduction of the miniaturized ILR, pediatric utilization has rapidly increased. The effect of this change on outcomes and value deserves further attention.

Colossal Permittivity and Multiple Effects in (Zn + Ta) co-doped TiO2 Ceramics

The search for giant dielectric constant materials is imperative because of their potential for important applications for the areas of device miniaturization and energy storage. In this work, we report a (Zn + Ta) co-doped TiO2 (ZTTO) ceramics that manifests high dielectric permittivity (>104) and low dielectric loss. This dielectric property shows a high stability in wide temperature range (25-200℃) and frequency range(20-106Hz). The crystalline structure, microstructure and dielectric properties of ZTTO ceramics were systematically investigated. XPS, Impedance spectroscopy and frequency dependent dielectric constant under DC bias results reveal that the colossal dielectric properties of (Zn2+1/3Ta5+2/3)xTi1-xO2 ceramics were mainly caused by electron-pinned defect-dipoles (EPDD) model, internal barrier layer capacitance (IBLC) effect and electrode effect. This work would provide a guidance to further researching the colossal permittivity CP materials.

All-Dielectric Meta-Surface for Multispectral Photography by Theta Modulation

The traditional theta modulator encodes input information by superimposing Ronchi sub-gratings, which is extremely easy to cause spatial channel overlap that results in bands mixing. In this case, we present an all-dielectric theta modulation meta-surface with a new encoding method, which separates red, green, blue, and achromatic spatial channels on the focal plane. The meta-surface ensures that the positions of focal points are relatively consistent while focusing energy into the sub-wavelength regions. Our study offers a way to facilitate device miniaturization and system integration, which may have an important application in compact multispectral photography only with one detector.