Concealable physical unclonable function generation and an in-memory encryption machine using vertical self-rectifying memristors.

The importance of hardware security increases significantly to protect the vast amounts of private data stored on edge devices. Physical unclonable functions (PUFs) are gaining prominence as hardware security primitives due to their ability to generate true random digital keys by exploiting the inherent randomness of the physical devices. Traditional approaches, however, require significant data movement between memory units and PUF generation circuits to perform encryption, presenting considerable energy efficiency and security challenges.

Enhancing Uniformity, Read Voltage Margin, and Retention in Three-Dimensional and Self-Rectifying Vertical Pt/TaO/AlO/TiN Memristors.

This study introduces a TaO-based self-rectifying memristor (SRM) with an AlO interfacial layer adopted to improve switching uniformity, read voltage margin, and long-term retention. The Pt/TaO/AlO/TiN (PTAT) device exhibits a 10 rectification ratio, 10 on/off ratio, 2 × 10 endurance, and retention of 10 s at 150 °C. A 3-layer 4 × 4 vertical resistive random access memory structure exhibits uniform switching parameters.

A stochastic photo-responsive memristive neuron for an in-sensor visual system based on a restricted Boltzmann machine.

In-sensor computing has gained attention as a solution to overcome the von Neumann computing bottlenecks inherent in conventional sensory systems. This attention is due to the ability of sensor elements to directly extract meaningful information from external signals, thereby simplifying complex data. The advantage of in-sensor computing can be maximized with the sampling principle of a restricted Boltzmann machine (RBM) to extract significant features.

Hyperplane tree-based data mining with a multi-functional memristive crossbar array.

This study explores the stochastic and binary switching behaviors of a Ta/HfO/RuO memristor to implement a combined data mining approach for outlier detection and data clustering algorithms in a multi-functional memristive crossbar array. The memristor switches stochastically with high state dispersion in the stochastic mode and deterministically between two states with low dispersion in the binary mode, while they can be controlled by varying operating voltages. The stochastic mode facilitates the parallel generation of random hyperplanes in a tree structure, used to compress spatial information of the dataset in the Euclidian space into binary format, still retaining sufficient spatial features.

Thresholding Computing with Heterogeneous Integration of Memristive Kernel with Metal-Oxide-Semiconductor Capacitor for Temporal Data Analysis.

Precise event detection within time-series data is increasingly critical, particularly in noisy environments. Reservoir computing, a robust computing method widely utilized with memristive devices, is efficient in processing temporal signals. However, it typically lacks intrinsic thresholding mechanisms essential for precise event detection.

In-Materia Annealing and Combinatorial Optimization Based on Vertical Memristive Array.

Due to its area and energy efficiency, a memristive crossbar array (CBA) has been extensively studied for various combinatorial optimization applications, from network problems to circuit design. However, conventional approaches include heavily burdening software fine-tuning for the annealing process. Instead, this study introduces the "in-materia annealing" method, where the inter-layer interference of vertically stacked memristive CBA is utilized as an annealing method.

Heterogeneous density-based clustering with a dual-functional memristive array.

In the big data era, the requirement for data clustering methods that can handle massive and heterogeneous datasets with varying distributions increases. This study proposes a clustering algorithm for data sets with heterogeneous density using a dual-mode memristor crossbar array for data clustering. The array consists of a Ta/HfO/RuO memristor operating in analog or digital modes, controlled by the reset voltage.

Comprehensive Assessment of Multidrug-Resistant and Extraintestinal Pathogenic in Wastewater Treatment Plant Effluents.

Multidrug-resistant (MDR) poses a significant threat to public health, contributing to elevated rates of morbidity, mortality, and economic burden. This study focused on investigating the antibiotic resistance profiles, resistance and virulence gene distributions, biofilm formation capabilities, and sequence types of strains resistant to six or more antibiotic classes. Among 918 strains isolated from 33 wastewater treatment plants (WWTPs), 53.

Nationwide evaluation of microplastic properties in municipal wastewater treatment plants in South Korea.

Wastewater treatment plants (WWTPs) are considered a significant microplastic discharge source. To evaluate the amount and characteristics of microplastics discharged from WWTPs in South Korea, we selected 22 municipal WWTPs nationally and investigated microplastics at each treatment stage. The mean microplastic removal efficiency by WWTPs was >99%, and most of the microplastics were removed by sedimentation with the second clarifier during wastewater treatment.

Implementation of Bayesian networks and Bayesian inference using a CuTe/HfO/Pt threshold switching memristor.

Bayesian networks and Bayesian inference, which forecast uncertain causal relationships within a stochastic framework, are used in various artificial intelligence applications. However, implementing hardware circuits for the Bayesian inference has shortcomings regarding device performance and circuit complexity. This work proposed a Bayesian network and inference circuit using a CuTe/HfO/Pt volatile memristor, a probabilistic bit neuron that can control the probability of being 'true' or 'false.

Vertically Stackable Ovonic Threshold Switch Oscillator Using Atomic Layer Deposited GeSe Film for High-Density Artificial Neural Networks.

Nanodevice oscillators (nano-oscillators) have received considerable attention to implement in neuromorphic computing as hardware because they can significantly improve the device integration density and energy efficiency compared to complementary metal oxide semiconductor circuit-based oscillators. This work demonstrates vertically stackable nano-oscillators using an ovonic threshold switch (OTS) for high-density neuromorphic hardware. A vertically stackable GeSe OTS-oscillator (VOTS-OSC) is fabricated with a vertical crossbar array structure by growing GeSe film conformally on a contact hole structure using atomic layer deposition.

2Memristor-1Capacitor Integrated Temporal Kernel for High-Dimensional Data Mapping.

Compact but precise feature-extracting ability is core to processing complex computational tasks in neuromorphic hardware. Physical reservoir computing (RC) offers a robust framework to map temporal data into a high-dimensional space using the time dynamics of a material system, such as a volatile memristor. However, conventional physical RC systems have limited dynamics for the given material properties, restricting the methods to increase their dimensionality.

Cross-Wired Memristive Crossbar Array for Effective Graph Data Analysis.

Graphs adequately represent the enormous interconnections among numerous entities in big data, incurring high computational costs in analyzing them with conventional hardware. Physical graph representation (PGR) is an approach that replicates the graph within a physical system, allowing for efficient analysis. This study introduces a cross-wired crossbar array (cwCBA), uniquely connecting diagonal and non-diagonal components in a CBA by a cross-wiring process.

Emergency contraceptive provision in the emergency department and risk analysis for delayed utilization in South Korea.

In certain nations, the emergency department (ED) has been designated as the primary center to provide emergency contraception (EC). However, analyses of ED visits for EC are limited. Moreover, ED-based research that focuses on time is limited to only a few surveys.

A high-dimensional in-sensor reservoir computing system with optoelectronic memristors for high-performance neuromorphic machine vision.

In-sensor reservoir computing (RC) is a promising technology to reduce power consumption and training costs of machine vision systems by processing optical signals temporally. This study demonstrates a high-dimensional in-sensor RC system with optoelectronic memristors to enhance the performance of the in-sensor RC system. Because optoelectronic memristors can respond to both optical and electrical stimuli, optical and electrical masks are proposed to improve the dimensionality and performance of the in-sensor RC system.

Characterization of seasonal behaviors of naturally occurring radioactive materials in a groundwater borehole using an in situ monitoring system.

Understanding the temporal behaviors of naturally occurring radioactive materials is important for safeguarding groundwater as a secure water resource for drinking, agriculture, and industry usage. This study reports the vertical profiles of U concentration and Rn activity and the management of in situ monitoring systems during intensive field sampling of a national groundwater-monitoring borehole for seven years (2015-2021). The aim was to capture the seasonal characteristics of the U concentrations and Rn activity.

Detection of microplastic traces in four different types of municipal wastewater treatment plants through FT-IR and TED-GC-MS.

Large amounts of microplastics are discharged into wastewater treatment plants (WWTPs), from where some of them are released into natural waterbodies on account of their not being fully eliminated by WWTPs. To investigate the behavior and emission of microplastics from WWTPs, we selected four WWTPs with different treatment technologies, including anaerobic-anoxic-aerobic (AO), sequence batch reactor (SBR), media, and membrane bioreactor (MBR). The number of microplastics detected using Fourier transform infrared (FT-IR) spectroscopy ranged from 520 to 1820 particles/L in influent and from 0.

Exposure to an accidental trichlorosilane spill: three case reports.

Chlorosilane is a hazardous chemical compound which is used as a raw material in the production of silicone. Despite strict restrictions, accidental spillage of chlorosilane is often reported. However, human exposure was rarely reported in the past decades and the effect on humans is barely known.

Local Behavior of Lap-Spliced Deformed Rebars in Reinforced Concrete Beams.

Twelve full-scale reinforced concrete beams with two tension lap splices were constructed and tested under a four-point loading test. Half of these beams had shorter lap splices than that recommended by American Concrete Institute Building Code ACI 318-19; they failed by bond loss between steel and concrete at the lap splice region before rebar yielding. The other half of the beams were designed with a lap splice length slightly exceeding that recommended by ACI 318-19; they failed by rebar yielding and exhibited a ductile behavior.

Development of diagnostic systems for wide range and highly sensitive detection of two waterborne hepatitis viruses from groundwater using the conventional reverse transcription nested PCR assay.

Waterborne epidemics of human hepatitis virus A and E (HAV and HEV) have been reported worldwide. Molecular biology techniques, such as reverse transcription polymerase chain reaction (RT-PCR), have been widely used to detect the two hepatitis viruses. However, comparative studies of various types of samples are needed, and different environmental factors, including the low copy pathogens, presence of PCR inhibitors in the sample, unknown non-specific reaction with template, and sequence diversity leading to new variants in viruses, should be considered.

High Mobility Group Box Chromosomal Protein-1 Induces Myofibroblast Differentiation and Extracellular Matrix Production via RAGE, p38, JNK and AP-1 Signaling Pathways in Nasal Fibroblasts.

Background: Chronic rhinosinusitis is involved in myofibroblast differentiation and extracellular matrix (ECM) accumulation. High mobility group box chromosomal protein 1 (HMGB-1) is known to stimulate lung fibroblast to produce ECM in lung fibrosis. The aim of this study was to investigate whether HMGB-1 induces myofibroblast differentiation and ECM production in nasal fibroblasts and to identify the signal pathway.

Spatial variation of pharmaceuticals in the unit processes of full-scale municipal wastewater treatment plants in Korea.

Several reports have elucidated the removal of pharmaceutical residues in municipal wastewater treatment plants (WWTPs). However, there remains a need to determine the spatial distribution of pharmaceuticals in the unit processes of full-scale municipal WWTPs. Herein, spatial variations of fifteen pharmaceuticals in the unit processes of four full-scale municipal WWTPs were assessed by analyzing both solid and liquid samples.