Digital Bits Research Articles

Epsilon negative dynamic coded THz metamaterial beamformer for digital information encryption

Light propagation facilitates digital information encryption by utilizing Epsilon Negative (ENG) metamaterials as a medium. Achieving the desired encryption hinges on synchronizing two pivotal features: the phase difference and the epsilon shifting of the metamaterials. The proposed metamaterial is intricately designed to represent digital bit 1 (states 0 and 1), contingent upon the arrangement of material multilayers within the metamaterial device. Specifically, state 1 is fashioned through a combination of Graphene and Gold, while state 0 is solely represented by Graphene on a metamaterial structure. The developed structure exhibits right hand metamaterial (epsilon of \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:+$$\\end{document}7.20) for state 0 and plasma metamaterial (epsilon \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:-$$\\end{document}6.94) for state 1 at 8.6 THz. Notably, the phase difference between 0 and 1 states is around \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:90^\\circ\\:$$\\end{document}. Primarily leveraging the synchronized combination phase and epsilon as the key design parameters for the metamaterial array, the beamforming pattern enables beam steering within the angular range of \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:+30^\\circ\\:$$\\end{document} to \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:-30^\\circ\\:$$\\end{document}. Secondly, employing a sophisticated material addition strategy involving Gallium Arsenide (GaAs) systematically manipulates the sidelobe in specific directions, thereby providing a mechanism to modulate the sidelobe and concurrently augment spatial resolution. After preparing the metamaterial coded (MC) lens, the source, lens and receiver strategically encrypt the scanning image, employing techniques including Doppler compression and 2D discrete Fourier transform. The proposed MC lens offers applicability like image encryption, security scanning, conveyor systems, hyperlenses and modern cryptography.

Toward mechanical proprioception in autonomously reconfigurable kirigami-inspired mechanical systems.

Mechanical metamaterials have recently been exploited as an interesting platform for information storing, retrieval and processing, analogous to electronic devices. In this work, we describe the design and fabrication a two-dimensional (2D) multistable metamaterial consisting of building blocks that can be switched between two distinct stable phases, and which are capable of storing binary information analogous to digital bits. By changing the spatial distribution of the phases, we can achieve a variety of different configurations and tunable mechanical properties (both static and dynamic). Moreover, we demonstrate the ability to determine the phase distribution via simple probing of the dynamic properties, to which we refer as mechanical proprioception. Finally, as a simple demonstration of feasibility, we illustrate a strategy for building autonomous kirigami systems that can receive inputs from their environment. This work could bring new insights for the design of mechanical metamaterials with information processing and computing functionalities. This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'.

Digital Mechanical Metamaterial with Programmable Functionality.

Digitization has brought a new era to the world, liberating information from physical media. The material structure-property relation is high-dimensional and nonlinear, and the digitization of structure-property relations may bring unprecedented functional programmability and diversity. Here, a new concept of digital mechanical metamaterial (DMM) is presented, where property design is realized by programming the digital states of the DMM to decouple the design of the structure and property. Transforming the binary stable states of a curved beam to the digital bit, one unit cell of DMM manifests three distinct deformation responses under compression, i.e., compression-twist coupling (CTC), compression-shear coupling (CSC), and pure compression (PC). These deformation modes show notable differences in motion and stiffness, which, by digitally programming a series of DMM, can yield a spectrum of functionalities, including information encryption, stress-strain relation customization, energy absorption in cushioning, effective vibration isolation, and tunable force transmission. This study pioneers a versatile material design paradigm that provides much greater freedom for the property design of intelligent mechanical metamaterials.

NIR-II light-encoded 4D-printed magnetic shape memory composite for real-time reprogrammable soft actuator

For the intelligent 4D-printed actuators, the excellent performance, including quickly reversible spatial-shape transformation and locking, digital and precise shape manipulation in real-time, and remote actuation in special spaces or harsh environments, is significantly desirable but still challenging. Here, using a UV-curable system containing the shape memory polymer (SMP) and NdFeB particles, namely the magSMP composite, we fabricate a real-time reprogrammable soft actuator via high-resolution Digital Light Processing (DLP)-based 4D printing. The printed structure is composed of an array of physical binary magSMP composite elements (m-bits), analogous to digital bits. Owing to the NdFeB's photothermal effect, each m-bit can be independently and reversibly switched between unlocking or locking states (allowing or prohibiting responsive shape-morphing) in response to the on/off state of NIR-II light. Through projecting NIR-II light patterns for encoding a set of binary instructions onto 4D-printed actuators, the real-time light-programmed deformations are induced precisely under an actuation magnetic field due to the NdFeB's huge coercivity. Thus, the synergistic magnetic and light field-manipulated multimodal deformations of actuators, including mimosa shape changing, grasping, and wire guiding, are achieved. This study shines lights on the fabrication of soft structures of arbitrary sizes and provides their future perspectives in soft robot design.

A 12-Bit 1.2-GS/s Current-Steering DAC in 45-NM CMOS Technology

This research paper presents a 12-bit 8–4-segmented current-steering DAC (digital-to-analog converter) that offers notable advantages, particularly in terms of its reduced power consumption compared to other similar designs. The exceptional performance of our DAC can be attributed to two key factors: the use of a thermometer encoder and an efficient digital input bit segmentation. These features contribute to enhanced precision and reduced power requirements, setting our DAC apart from the existing solutions in the field. These enhancements significantly reduce glitches and improve the accuracy of the DAC’s output. DAC dissipates a total power of about 44.95[Formula: see text]mW when running at a sample rate of 1.2[Formula: see text]GHz with the CMOS technology of 45[Formula: see text]nm. While the supply input voltage is held constant at 1.2[Formula: see text]V, the DAC’s digital input is pulsating in nature in which the ON voltage is 1[Formula: see text]V and OFF voltage is 0[Formula: see text]V. Also, the DAC has a spurious-free dynamic range (SFDR) of 41.77[Formula: see text]dB.

Cryptographic transistor for true random number generator with low power consumption.

We design a cryptographic transistor (cryptoristor)-based true random number generator (tRNG) with low power consumption and small footprint. This is the first attempt to use irregular and unpredictable operation-induced randomness of a cryptoristor as an entropy source. To extract discrete random numbers with a binary code from the cryptoristor, we developed a noise-coupling analog-to-digital converter. This converter not only converts analog signals to digital random bits but also improves the randomness of the entropy source with low power consumption. The randomness of the cryptoristor is attributed to the random carrier multiplications with the creation and stochastic carrier escape as destruction, which occurs iteratively as long as the input current is fed. The cryptoristor-based tRNG passed 15 randomness test suites of NIST Special Publication 800-22. It is robust to iterative operational stresses and to ambient temperature changes, making it an attractive option for hardware-based security solutions in the Internet of Things due to its low power consumption and small size.

Semantic Technologies to Model Battery Data and Knowledge

Data-intensive battery research is here to stay. With open data incentives on the rise and simpler software interfaces granting access to powerful machine learning algorithms, researchers are uncovering a wealth of insights from battery data. However, data without context are just unusable digital bits. Battery data must be appropriately described to render it interoperable and reusable for traditional and data-intensive research. This requires overcoming numerous challenges associated to data heterogeneity, inconsistency, standardization, and meaning. Semantic technologies address these challenges by providing a unified and flexible framework for integrating and reasoning about data from heterogeneous sources.In this contribution, we will introduce Semantic Technologies and how they enable both human and software agents to understand and reuse battery data. We will present the tools we are developing to i) encourage the adoption of a common standard vocabulary to describe the battery domain[1], ii) connect research resources (datasets, experts, reports, publications, projects) within an accessible platform[2], and iii) reduce the effort required to upgrade data with semantic context. Overall, these tools take concrete steps towards guaranteeing compliance with FAIR data principles. We will further outline plans for future development, including strategies for reaching out to the global battery landscape, facilitate the curation of battery data for data-driven research, and enable knowledge exploration via natural language models.[1] S. Clark et al., "Toward a Unified Description of Battery Data," Adv. Energy Mater., vol. 2102702, 2021.[2] https://github.com/BIG-MAP/Demo-BatteryDataSemanticSearch

A STUDY ON THE APPLICATION OF BLOCKCHAIN TECHNOLOGY SUPPORTS CRYPTOCURRENCY

A Blockchain is essentially a distributed database of records, or public ledger, of all completed and shared transactions or digital events. Each transaction in the public ledger is validated by a majority of the system's members. Information can never be deleted after it has been submitted. The Blockchain includes a precise and verifiable record of every single transaction that has ever occurred. The most well-known application of Blockchain technology is Bitcoin, a decentralized peer-to-peer digital money. Although the digital currency bit coin is very contentious, the underlying Blockchain technology has performed perfectly and has found a wide range of uses in both the financial and non- financial worlds. The basic idea is that the Blockchain creates a means for achieving distributed consensus in the digital online world. By producing an unquestionable record in a public ledger, involved entities may be assured that a digital event occurred. It paves the way for the transition from a centralized to a democratic, open, and scalable digital economy. This innovative technology offers huge possibilities, and the change in this field has just begun. This research paper describes Blockchain technology supports crypto currency and some specific applications in both the financial and non- financial sector and also this research paper will examine the difficulties that lie ahead and the business opportunities for this fundamental technology that is going to transform our digital world. Keywords: Blockchain, Bitcoin, Financial and non-financial sector, Technology

Programmable PVT compensated dual output resistance tunable current controlled conveyor

ABSTRACT In the existing dual output resistance tunable current controlled conveyor (DO-RTCCCII), a resistance trimming block is added at the X terminal () which is controlled by programmable bits. includes the variations due to bias current (i.e. intrinsic resistance, RX) and due to setting of digital bits. However, the PVT variations may cause deviations in bias current, thus leading to inaccuracies in the design parameters. To address this, a programmable PVT compensated DO-RTCCCII (PPC-DO-RTCCCII) is proposed. It uses a reference generation section along with DO-RTCCCII. The reference generation section uses bias compensation bits for PVT independent bias current generation and also provides flexibility to get desired bias current through current multiplication bits. The operation of the proposed PPC-DO-RTCCCII has been designed and simulated using 28 nm CMOS technology through the simulator ELDO (AMS) tool of Mentor graphics. The post layout simulations closely match with pre layout simulations. A filter circuit is also included to illustrate the usefulness of the proposal.

All-optical digital-to-analog conversion based on time-domain pulse spectrum encoding

An all-optical digital-to-analog conversion (DAC) scheme based on time-domain pulse spectrum encoding is proposed and experimentally demonstrated. In this approach, the ultrafast optical pulses are first time-broadened and frequency-chirped based on wavelength-to-time mapping and then segmented and power weighted in both time and spectrum domains to produce the multi-band optical carrier. The optical carrier is intensity-modulated by the serial digital inputs to realize the time-domain pulse spectrum encoding. Each spectrum-encoded pulse is then time-compressed to achieve the incoherent weighted intensity summation of digital bits within each word. This approach generates the multi-band optical carrier and achieves the corresponding incoherent intensity summation using all-fiber structure; the system configuration is greatly simplified. Moreover, the time-domain pulse spectrum encoding could efficiently exploit the superwide spectrum resource offered by ultrafast optical pulses and potentially improve the system conversion resolution. A proof-of-concept experiment of a 4-bit DAC system based on time-domain pulse spectrum encoding is carried out, and the obtained results validate the feasibility of the proposed approach. In addition, the system performance in terms of the effective number of bits is investigated.

Entaglement and communication in digital qubits using FPGAs

Abstract This paper focuses on usage of digital qubits on a digital quantum computing platform implemented on FPGAs. Modifications have been made to existing digital qubit standards to account for complex probability amplitudes and not only real ones. This paper introduces an improved transient effect ring-oscillator based TRNG used in the scope of this project. The objective of this was to simulate the addition of environmental noise in a digital setting. Using the newly designed digital qubits, a few quantum logic gates have been designed to work on the FPGA platform using Verilog. These logic gates have then been used to implement entanglement on a digital hardware platform. Furthermore, this paper implements communication between two digital quantum computers over both wired and wireless media by transmitting alphabetical messages as qubits and compares the same with transmission involving classical digital bits only.

A Numerical Splitting and Adaptive Privacy Budget-Allocation-Based LDP Mechanism for Privacy Preservation in Blockchain-Powered IoT

Blockchain has gradually attracted widespread attention from the research community of the IoT, due to its decentralization, consistency, and other attributes. It builds a secure and robust system by generating a backup locally for each participant node to collectively maintain the network. However, this feature brings some privacy concerns since all nodes can access the chain data, users' sensitive information under risk of leakage. The local differential privacy (LDP) mechanism can be a promising way to address this issue as it implements data perturbation before uploading to the chain. While traditional LDP mechanisms cannot fit well with blockchain since the requirements of a fixed input range, large data volume, and using the same privacy budget, which are practically difficult in a decentralized environment. To overcome these problems, we propose a novel LDP mechanism to split input numerical data and implement perturbation by digital bits, which does not require a fixed input range and large data volume. In addition, we use an iteration approach to adaptively allocate the privacy budget for different perturbation procedures that minimize the total deviation of perturbed data and increase the data utility. We employ mean estimation as the statistical utility metric under the same and randomized privacy budgets to evaluate the performance of our novel LDP mechanism. The experiment results indicate that the proposed LDP mechanism performs better in different scenarios, and our adaptive privacy budget allocation model can significantly reduce the deviation of perturbation function to provide high data utility while maintaining privacy.

A dual-output switched-capacitor regulator with a self-controlled ripple reduction technique for self-powered EEG acquisition

In this paper, a novel dual-output switched-capacitor (SC) regulator is designed for EEG acquisition. At first, an efficient reconfigurable SC is designed with conversion ratios of 2/3 and 1/4 from 1.3 V input voltage. Reconfigurable SC with pulse frequency modulation (PFM) technique produces two single output voltages of 0.8 V and 0.2 V by changing the digital bit S. Then, a novel algorithm is proposed to produce two output voltages simultaneously and reduce voltage ripple. This SC regulator is self-controlled, and its control digital bits are entirely generated by the control logic circuit. Load current range is proportional to the EEG acquisition, in the range of 5 nA-1 μA and 500 nA-260 μA, for output voltages of 0.2 V and 0.8 V, respectively. The proposed dual-output SC is simulated in TSMC 65 nm CMOS technology and occupies an area of 2.09 mm2. The proposed SC regulator achieves a maximum power efficiency and output power of 92.8% and 193 μW, respectively.

Design of fully differential fast SCL Schmitt-trigger delay element with tunable delay and hysteresis in design and run-time

Tuning the delay of the circuit during the circuit performance can give a chance to a circuit to reduce Process, Voltage and Temperature (PVT) effects on delay and frequency by resetting its delay in feedback. This paper presented a full differential Schmitt-trigger (ST) with tunable delay and hysteresis. The delay-hysteresis setting is done in the design phase by tuning the biasing current, sizing, bias voltage and also during the execute phase (run time) by a digital bit and restructuring the circuit and delay route. The presented ST can have high and low delays with different frequencies using a digital bit in the circuit. This can help the band selection for multi-band applications. A Flip Voltage Follower (FVF) circuit is used for the current tail to increase the current and increase the frequency bands. In this Schmitt-trigger delay changes associated with restructuring result in a 40 % power reduction. A circuit analysis for the equivalent circuit of the presented circuit has also been done and the factors affecting the frequency and delay change have been analyzed and investigated in the simulation. Monte Carlo and PVT analysis have also been performed for circuit accuracy. Power changing with an incremental delay in CMOS is improved and almost monotonous by designing Source-Coupled-Logic (SCL) Schmitt-trigger.

Dynamic Precision Analog Computing for Neural Networks

Analog electronic and optical computing exhibit tremendous advantages over digital computing for accelerating deep learning when operations are executed at low precision. Although digital architectures support programmable precision to increase efficiency, analog computing architectures today only support a single, static precision. In this work, we characterize the relationship between the effective number of bits (ENOB) of precision of analog processors, which is limited by noise, and digital bit precision for quantized neural networks. We propose extending analog computing architectures to support dynamic levels of precision by repeating operations and averaging the result, decreasing the impact of noise. To utilize dynamic precision, we propose a method for learning the precision of each layer of a pre-trained model without retraining network weights. We evaluate this method on analog architectures subject to shot noise, thermal noise, and weight noise and find that employing dynamic precision reduces energy consumption by up to 89% for computer vision models such as Resnet50 and by 24% for natural language processing models such as BERT. In one example, we apply dynamic precision to a shot-noise limited homodyne optical neural network and simulate inference at an optical energy consumption of 2.7 aJ/MAC for Resnet50 and 1.6 aJ/MAC for BERT with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${&lt; }2\%$</tex-math></inline-formula> accuracy degradation, implying that the optical energy consumption is unlikely to be the dominant cost.

공중 폭발 탄에 탄속 및 거리정보를 입력하기 위한 전자석 Yoke의 자기장 해석

원하는 거리에서 공중에서 탄을 폭발시키는 방법(ABM: Air Busting Munition)이 개발되고 있다. 이 방식은 원하는 표적만을 정밀 타격할 수 있는 능력을 확보하는 것으로 전장에서 건물, 참호 등과 같은 엄폐물에 차폐된 표적을 효과적으로 제압하기 위한 수단이다. 또한 공중에 있는 표적도 높은 확률로 제압할 수 있어서 최근에는 드론의 공격을 막는 방법으로도 ABM 기술이 개발되고 있다. 본 연구에서는 탄이 총구를 지나갈 때 공중폭발탄에 탄속과 폭발시키려는 목표물의 거리 정보를 탄에 입력하는 방식을 선택하였다. 총구에 여러 개의 전자석 yoke 장치를 이용하여 직렬통신 방식으로 정보를 입력하는 방식을 고안하였다. 직렬통신방법으로 start bit, stop bit, data bit 및 parity bit를 탄에 입력하면, 탄에 장착된 M CU가 start bit과 stop bit 사이의 시간을 측정하고 두 yoke사이의 간격으로 부터 탄의 총구 속도를 계산하여, data bit로부터 얻은 거리정보와 계산된 탄속 정보로 탄의 기폭시간을 설정하는 방식을 택하였다. 이 방식의 구현 가능성을 확인하기 위하여 F EM 시뮬레이션을 수행하였다. Yoke의 크기는 25mm 탄에 적합한 크기를 설정하였으며, yoke의 폭이 6 mm, yoke 사이의 간격이 4mm인 경우, yoke의 자극면에서 1 mm 거리에서 자기장을 측정할 경우 탄에 digital bit 정보를 잘 입력할 수 있음을 확인할 수 있었다.

Redshift: Manipulating Signal Propagation Delay via Continuous-Wave Lasers

We propose a new laser injection attack Redshift that manipulates signal propagation delay, allowing for precise control of oscillator frequencies and other behaviors in delay-sensitive circuits. The target circuits have a significant sensitivity to light, and a low-power continuous-wave laser, similar to a laser pointer, is sufficient for the attack. This is in contrast to previous fault injection attacks that use highpowered laser pulses to flip digital bits. This significantly reduces the cost of the attack and extends the range of possible attackers. Moreover, the attack potentially evades sensor-based countermeasures configured for conventional pulse lasers. To demonstrate Redshift, we target ring-oscillator and arbiter PUFs that are used in cryptographic applications. By precisely controlling signal propagation delays within these circuits, an attacker can control the output of a PUF to perform a state-recovery attack and reveal a secret key. We finally discuss the physical causality of the attack and potential countermeasures.

Digital mobile fronthaul based on delta-sigma modulation employing a simple self-coherent receiver

The coherent digital radio-over-fiber (DRoF) system is a promising candidate for future mobile fronthaul networks (MFNs) due to its high receiver sensitivity and excellent robustness against nonlinearities. However, conventional coherent receivers with complicated structure and heavy algorithms are too expensive and power-hungry for cost-sensitive MFN applications. In addition, currently deployed digital MFNs based on common public radio interface (CPRI) suffer from low spectral efficiency and high data rate. Towards these issues we propose a novel DRoF downlink scheme employing a simple self-coherent receiver. In baseband unit (BBU), the radio signal is converted to a digital bit stream by a band-pass delta-sigma modulator (BP-DSM), which can be simply recovered with the utilization of a band-pass filter at the receiver. In remote radio unit (RRU), an electro-absorption modulated laser (EML) acts as a low-cost coherent homodyne receiver in virtue of injection locking technique. In the experiment, the injection-locked operation of the DSM signal is successfully achieved, and two modified schemes are proposed for the DSM signal to increase the locking range with a tolerable sensitivity penalty. The experimental results demonstrate the superiority of our approach in two aspects: 1) the EML-based coherent receiver outperforms a PIN photodiode in terms of receiver sensitivity; 2) compared to the analog RoF system, a 5-dB improvement in loss budget is obtained when DSM is employed with the aid of a simple equalizer.

A dither‐less bit weight digital background calibration for bridge capacitor digital‐to‐analog converter successive approximation register analog‐to‐digital converters

The authors present a dither-less background digital bit weights calibration method for split-capacitor digital-to-analog converter (CDAC) successive approximation register (SAR) analog-to-digital converters (ADCs) to improve non-linearities caused by capacitor mismatch and bridge-capacitor inaccuracy errors in a split-CDAC. By using a digital pseudo-random number (PN) generator and paired comparators with opposite offsets, a dither-less background calibration quickly reaches the target signal-to-noise-and-distortion ratio (SNDR) within 5 × 104 samples for various process uncertainties. The simulated performance using a behavioural 6-bit + 6-bit ADC with 1-bit redundancy for various random offset and capacitor mismatches shows that the SNDR increases from 45.7 to 65.7 dB after the calibration.

Reversible Secured Data Hiding using Binary Encryption and Digital Bit Modification Scheme

The information is getting precious day by day because of the digital revolution and more reach exposure of citizens to technology. The security of information is in demand and the topmost priority among researchers to develop data security systems. Image steganography is one of the data hiding schemes which is invisible in nature, although it uses visible image media to hide information. Steganography is not only limited to images. There are other media like text, audio, or video that can be utilized for hiding information. In this research work, a novel data hiding is being developed using an image as cover media. Researchers are facing during the development of the technique is maintaining the payload capacity as well as higher PSNR values and other parameters. This work uses colour images as cover and digital bit modification methods to hide secure information. Only hiding is not enough to secure information. There is an additional layer of security added by encrypting a secure message using an encryption method. The digital bit modification method is unconventionally spread the sequential bitstream over channels. This would make this approach unique and better as it is keeping the PSNR level higher along with NCC and lower MSE. All this is done by keeping the payload capacity as the maximum available. The average value of PSNR is 60.295dB, NCC is 1.00, and MSE is 0.1567.