Physical Transmission Research Articles

The impact of face coverings on audio-visual contributions to communication with conversational speech

The use of face coverings can make communication more difficult by removing access to visual cues as well as affecting the physical transmission of speech sounds. This study aimed to assess the independent and combined contributions of visual and auditory cues to impaired communication when using face coverings. In an online task, 150 participants rated videos of natural conversation along three dimensions: (1) how much they could follow, (2) how much effort was required, and (3) the clarity of the speech. Visual and audio variables were independently manipulated in each video, so that the same video could be presented with or without a superimposed surgical-style mask, accompanied by one of four audio conditions (either unfiltered audio, or audio-filtered to simulate the attenuation associated with a surgical mask, an FFP3 mask, or a visor). Hypotheses and analyses were pre-registered. Both the audio and visual variables had a statistically significant negative impact across all three dimensions. Whether or not talkers’ faces were visible made the largest contribution to participants’ ratings. The study identifies a degree of attenuation whose negative effects can be overcome by the restoration of visual cues. The significant effects observed in this nominally low-demand task (speech in quiet) highlight the importance of the visual and audio cues in everyday life and that their consideration should be included in future face mask designs.

Compressed Sensing for Biomedical Photoacoustic Imaging: A Review.

Photoacoustic imaging (PAI) is a rapidly developing emerging non-invasive biomedical imaging technique that combines the strong contrast from optical absorption imaging and the high resolution from acoustic imaging. Abnormal biological tissues (such as tumors and inflammation) generate different levels of thermal expansion after absorbing optical energy, producing distinct acoustic signals from normal tissues. This technique can detect small tissue lesions in biological tissues and has demonstrated significant potential for applications in tumor research, melanoma detection, and cardiovascular disease diagnosis. During the process of collecting photoacoustic signals in a PAI system, various factors can influence the signals, such as absorption, scattering, and attenuation in biological tissues. A single ultrasound transducer cannot provide sufficient information to reconstruct high-precision photoacoustic images. To obtain more accurate and clear image reconstruction results, PAI systems typically use a large number of ultrasound transducers to collect multi-channel signals from different angles and positions, thereby acquiring more information about the photoacoustic signals. Therefore, to reconstruct high-quality photoacoustic images, PAI systems require a significant number of measurement signals, which can result in substantial hardware and time costs. Compressed sensing is an algorithm that breaks through the Nyquist sampling theorem and can reconstruct the original signal with a small number of measurement signals. PAI based on compressed sensing has made breakthroughs over the past decade, enabling the reconstruction of low artifacts and high-quality images with a small number of photoacoustic measurement signals, improving time efficiency, and reducing hardware costs. This article provides a detailed introduction to PAI based on compressed sensing, such as the physical transmission model-based compressed sensing method, two-stage reconstruction-based compressed sensing method, and single-pixel camera-based compressed sensing method. Challenges and future perspectives of compressed sensing-based PAI are also discussed.

Lamb waves-based PCF-DMA: An anti-interference synchronous independent data transmission scheme for multiple cross-space users

Due to the high cost and safety risk brought about by wire penetration within the aerospace and underwater structure, reliable wireless cross-space multiple access transmission techniques become highly necessary. Lamb waves data transmission is recognized as a feasible solution, since it utilizes the solid structures as the transmission medium without being affected by electromagnetic radiation. However, in the case of synchronous transmission of multiple users, the aggravation of inter-access interference would severely weaken the reliability of the transmission system. Focusing on the issue of anti-interference synchronous independent data transmission for multiple cross-space users, this study proposes a Lamb waves-based pulse code frequency division multiple access (PCF-DMA) scheme. Firstly, a fast pulse position modulation strategy is established to improve the transmission rate. Considering the characteristics of the Lamb waves excitation pulses as the codeword, a PCF-DMA multiple access encoding method is designed. Secondly, by sparsely representing the Lamb waves physical transmission channel, a shift-invariant sparse deconvolution technology is proposed for decoding. Specially, to achieve reliable multiple access transmission with the PCF-DMA scheme, a normalized cross-correlation coefficient is used as the design criterion of the Lamb wave pulses. To validate these concepts, a three-user PCF-DMA data transmission system based on Lamb waves is built. The experimental results illustrate that the proposed design criterion can accurately predict the reliability of the multiple access transmission system. The bit error rate (BER) of the proposed PCF-DMA scheme is 30 % lower than that of conventional FDMA within a signal-to-noise ratio of −12 to 8 dB. Further, the influence factor analysis for the BER and communication rate are conducted. Finally, a synchronous independent data transmission for multiple cross-space users is achieved, with a maximum communication rate of 92.9 kbps per user and a BER below 0.17 %.

Research on Secure Physical Layer Transmission Assisted by Intelligent Reflective Surfaces

Intelligent Reflecting Surface (IRS) consists of large-scale low-cost passive reflective elements that can reflect and change the base station beam by changing the phase of the reflective units, thus enhancing the security of the physical layer of wireless communications. In the communication system, we will use the security rate to compare the confidentiality performance of a certain transmission signal. In this paper, we study the optimization problem of maximizing the security rate, and propose an alternating iteration method to decompose the problem which has more dimensions and the parameters are coupled with each other, and then design a suitable solution for each phase. Simulation results show a reduction in complexity and a greater advantage in the performance of the designed algorithm.

Circulation in the time of COVID-19: An analysis of physical material data in an academic library

For the last decade or more, circulation numbers of physical materials have declined in academic libraries across the United States. In the spring of 2020, the COVID-19 pandemic drastically altered society and daily life, not to mention library functions. In particular, fears of contagion via physical surfaces and transmission by contact led many libraries to shutter their in-person services or temporarily close altogether. The circulation of physical materials was hit particularly hard, as the ability to browse shelves, check out items, access interlibrary loan, and a host of other similar services were curtailed. This article will examine the statistical markers of physical material handling (checkouts, renewals, item browses, etc.) for two years before and after the pandemic, to reach conclusions about how COVID-19 impacted usage, what we can tell about general patterns in circulation before and due to these changes, and ultimately what these numbers tell us about the future of traditional material use.

Lightweight privacy-preserving authentication mechanism in 5G-enabled industrial cyber physical systems

With the deep integration of informatization and industrialization, cyber-physical system (CPS), which integrates computing, communication and control technologies, comes into being and has been widely used in industrial applications. A large number of information physical system devices and control systems are based on open internet connections, and security and privacy protection issues are gradually emerging, especially in the process of dynamic and difficult to control information physical system stream data transmission and storage, which will face new security threats. To alleviate these issues, user authentication mechanisms can prevent unauthorized access by adversaries in the CPS environment. For this purpose, we put forth a lightweight privacy-preserving authentication scheme for 5G-enabled ecosystems. This method utilizes edge devices to save online transaction data in network and securely transmits IoT devices data from the sensors to the edge gateway. Then, the edge gateway delivers and stores these data in the cloud. A detailed comparative study based on experimental results indicates that our proposal achieves a better balance between security and functionality features, communication and capitulation costs compared to other existing competitive solutions.

All-digital Device-compatible Real-time Physical Layer Secure Transmission based on Delta-sigma Modulation

All-digital Device-compatible Real-time Physical Layer Secure Transmission based on Delta-sigma Modulation

Superomniphobic and Photoactive Surface Presents Antimicrobial Properties by Repelling and Killing Pathogens.

Healthcare-acquired infections place a significant burden on the cost and quality of patient care in hospitals. Reducing contamination on surfaces within healthcare environments is critical for halting the spread of these infections. Herein, we report a bifunctional─repel and kill─surface developed using photoactive TiO2 nanoparticles integrated into a hierarchical scaffold (OmniKill). To quantify the repellency of OmniKill, we developed a touch-based assay, capable of simulating the transfer of individual pathogens, multiple pathogens, or pathogen-latent fecal matter from hands to surfaces. OmniKill repels bacterial pathogens by at least 2.77-log (99.8%). The photoactive material within OmniKill further reduces the viability of transferred pathogens on the surface by an additional 2.43-log (99.6%) after 1 h of light exposure. The antipathogenic effects─repel and kill─remain robust under complex biological contaminates such as feces. These findings show the potential use of OmniKill in reducing the physical transmission of bacterial pathogens in healthcare settings.

Multi-User Orbital Angular Momentum Based Terahertz Communications

Terahertz (THz) wireless communications are commonly regarded as one of the key technologies of 6G communication. Combined with THz, the newly exploited physical layer transmission dimension orbital angular momentum (OAM) that multiplexes a set of orthogonal modes on the same frequency channel, can unleash its potential in achieving high spectrum efficiency. Currently, most of the research on radio OAM communications focus on the point-to-point scenario in microwave and millimeter-wave (mmWave) bands. In this paper, we propose a uniform circular array (UCA)-based THz multi-user OAM (MU-OAM) communication system including downlink and uplink transmission schemes that simplifies the signal detection to the despiralization and amplitude detection (AD). A salient feature of the proposed MU-OAM communication scheme is lower computational complexity than the traditional MU-MIMO scheme without sacrifacing bit error rate (BER) and achievable sum rate performances, which is validated by mathematical analysis and numerical simulations.

Oxides dispersion-strengthened (ODS) FeCoNiCuZn high entropy alloys through different rare earth elements: Synthesis, structural, physical, and experimental radiation transmission properties

The oxide dispersoids within ODS alloys can act as sinks for radiation-induced defects, such as vacancies and dislocation loops, effectively reducing their mobility and preventing their accumulation. This property is crucial for HEAs employed in radiation-intensive environments, such as nuclear reactors. The objective of this research is to examine the impact of rare earth elements (REE) such as Y2O3, Er2O3, Pr2O3, and Sm2O3, on Oxides Dispersion-Strengthened (ODS) FeCoNiCuZn High Entropy Alloys (HEAs). The mechanical alloying technique is employed to produce a high entropy alloy consisting of Fe, Co, Ni, Cu, and Zn in their raw form. Subsequently, the raw alloy powder is enriched with separate amounts of Y2O3, Er2O3, Pr2O3, and Sm2O3. The microstructural analysis of the samples obtained from the mechanical alloying process was performed utilizing the X-ray diffraction (XRD) technique. In addition, scanning electron microscopy (SEM) was employed to analyze the ODS-HEA samples encoded S1, S2, S3, S4, and S5. To investigate the transmission properties of gamma-ray and neutron radiation, experimental studies are carried out using two types of detectors: Ultra High Purity Germanium (HPGe) detector and Canberra NP-100B BF3 gas proportional detector, respectively. The X-ray diffraction (XRD) spectra of samples did not display any observable peaks that could be attributed to the presence of dispersed rare earth element (REE) oxides. The uniform distribution of the metallic constituents that make up the High Entropy Alloy (HEA) is observed in the samples. Additionally, it can be observed that the implementation of the ODS-HEA technique, incorporating a 3% (wt.) Er2O3 additive, results in the most advantageous results with respect to the characteristics of gamma ray absorption. The S3 sample demonstrated the greatest degree of neutron absorption, as demonstrated by a recorded value of 0.857 μSv/h, where the S1 sample demonstrated the minimum level of absorption, as evidenced by a recorded value of 0.452 μSv/h. Based on the observed effects on neutron and gamma-ray attenuation behaviors in ODS-HEAs, it can be concluded that Er2O3 exhibits characteristics of a monotonic oxide. This feature is particularly advantageous for applications that necessitate a dual enhancement in these behaviors. It can also be concluded that the S1 sample may be deemed appropriate for situations where the utmost consistency of chain reactions in nuclear reactor fuel rods is desired, due to its possession of the lowest neutron absorption properties.

The Role of Virgin Coconut Oil in Corn Starch/NCC-Based Nanocomposite Film Matrix: Physical, Mechanical, and Water Vapor Transmission Characteristics.

Corn starch-based nanocomposite films usually have low moisture barrier properties. Adding virgin coconut oil (VCO) as a hydrophobic component can improve the nanocomposite film's characteristics, especially the film's permeability and elongation properties. This study aimed to determine the role of VCO with various concentrations (0, 3, 5 wt%) on the physical, mechanical, and water vapor transmission characteristics of corn starch/NCC-based nanocomposite films. Adding 3% VCO to the film showed the lowest WVTR value by 4.721 g/m2.h. At the same time, the value of tensile strength was 4.243 MPa, elongation 69.28%, modulus of elasticity 0.062 MPa, thickness 0.219 mm, lightness 98.77, and water solubility 40.51%. However, adding 5 wt% VCO to the film increased the film's elongation properties by 83.87%. The SEM test showed that adding VCO formed a finer structure with pores in several areas. The FTIR films showed that adding VCO caused a slightly higher absorption peak shift at the O-H groups and new absorption peaks at wave numbers 1741 cm-1 and 1742 cm-1. The results of this study may provide opportunities for the development of nanocomposite films as biodegradable packaging in the future.

Preparation of rich hydrocarbon biofuels from cracking of waste cooking oil by CaO@Zn-KIT-6

The preparation of biofuel from bio-oils is of great importance to the development of renewable energy and to alleviate environmental pollution problems. In this work, acidic mesoporous silica Me-KIT-6 (Me = Zn, Al, Zr, Sn, Mn) were prepared and coated with basic metal oxides, and the CaO@Me-KIT-6 catalyst was obtained, and tested in the catalytic cracking reaction of waste oils and fats. The structure of the catalyst was characterized by X-ray diffraction, N2 physical adsorption and transmission electron microscopy (TEM), the acidity/basicity was characterized by chemisorption (NH3-TPD/CO2-TPD), and the structure-performance relationship in waste cooking oil catalytic cracking was investigated in detail. The results showed that CaO@Zn-KIT-6 catalyst had a good catalytic performance with a liquid biofuel yield of 66.30% and an acid value of about 23.35 mg KOH/g. The carbon distribution of the liquid biofuel concentrated in the range of C13-C18 with 67.80% of hydrocarbon products. The synthesized core-shell catalysts displayed multifunctional role resulting from tailored acid-base synergy.

Designing a Lead-free and high-density glass for radiation facilities: Synthesis, physical, optical, structural, and experimental gamma-ray transmission properties of newly designed barium-borosilicate glass sample

We report the design, synthesis, optical, structural, and gamma-ray attenuation properties of a newly developed Lead-free and high-density borosilicate glass sample for its potential applications in medical and industrial radiation facilities. A barium-borosilicate glass sample (BSBaZn) was designed and synthesized using nominal composition of 7B2O3-50SiO2-38ZnO-5BaO. The FTIR spectrum of the BSBaZn is revealed four fundamental regions. These regions are 400–620 cm−1, 620–770 cm−1, 800–1210 cm−1, and 1210–1500 cm−1. Transmittance rate in the wavelength range of 350–1100 nm is reported as 80 %. A high-purity Germanium (HPGe) detector along with an energetic 133Ba radioisotope is also utilized for experimental gamma-ray transmission studies. Various fundamental gamma-ray shielding parameters of BSBaZn are determined and accordingly compared with many other glass shields. MCNPX (version 2.7.0) general purpose Monte Carlo code is utilized for gamma-ray transmission factor (TF) values. The results showed that the synthesized BSBaZn sample has promising structural, optical, and physical properties in addition to promising gamma-ray attenuation properties. The high transparency of BSBaZn along with its high-density may be considered as an important selection criterion for its implementation in protection purposes in medical and industrial radiation facilities, where the source and patients monitoring play a significant role.

Real-time stealth optical transmission via dither-remodulation in a bias controller of a Mach-Zehnder modulator.

The physical layer transmission security is a promising technology against security threats. As an effective supplement to the encryption strategy, steganography has received widespread attention. We report a real-time 2 kbps stealth transmission in the 10 Gbps dual polarization QPSK public optical communication. The stealth data is embedded in dither signals via precise and stable bias control technique for a Mach-Zehnder modulator. In the receiver, the stealth data can be recovered from the normal transmission signals by low SNR signal processing and digital down conversion. The stealth transmission has been verified to pose almost no impact on the public channel over a 117 km distance. The proposed scheme is compatible with existing optical transmission systems, so that no new hardware needs to be employed. It can be accomplished and is exceeded economically by adding simple algorithms, which utilizes only a small amount of FPGA resources. The proposed method can cooperate with encryption strategies or cryptographic protocols at different network layers to reduce the communication overhead and improve the overall security of the system.

Research and Implementation of CPS for Transmission Front Middle Case Assembly Line

As an indispensable part of the automobile factory transmission system, the transmission assembly line has a high level of automation and can play as a pioneer in the digital transformation of production. However, for the transmission production process, especially the front and middle case, there are many problems, such as a low degree of informatization, low efficiency of information transmission, and lack of a platform for rapid information release and sharing. This leads to the difficulty of timely discovery and feedback of exceptional events, resulting in low assembly efficiency. Therefore, this paper constructs its cyber–physical system (CPS) with the help of the Internet of Things (IoT) technologies, such as physical identification, information collection, and transmission. It contributes to improving the intelligent level of transmission of front and middle case assembly, strengthening the close integration, interaction, and collaboration between a large amount of assembly data and the physical entity of the assembly process, realizing the real-time monitoring of the transmission front and middle case assembly process, timely discovering, provide feedback, and dealing with exceptional events. In addition, scientific and effective adjustment strategies based on the data can be provided. Ultimately, the assembly efficiency of the transmission front and middle case is improved, ensuring the stability of the assembly line.

An Anonymous Authentication and Secure Communication Protocol in Ad-Hoc Networks

Abstract: The one-time pad (OTP) stable transmission is based at the random keys to acquire best secrecy, whilst the unpredictable wi-fi channel is proven to be an awesome random source. There is only a few paintings of the joint layout of OTP and key era from wi-fi channels. This paper presents a complete and quantitative research on stable transmission accomplished with the use of using OTP and wi-fi channel randomness. We recommend OTP stable transmission schemes, i.e., Identical Keyprimarily based totally Physical Layer Secure Transmission (IK-PST) and Un-Same Key-primarily based totally Physical-layer Secure Transmission (UK-PST). We quantitatively examine the overall performance of each schemes and show that UKPST outperforms IK-PST. We enlarge the pairwise techniques to a collection of customers in networks with super mega celebrity and chain topologies. We put in force prototypes of each schemes and examine the proposed schemes thru each simulations and experiments. The consequences confirm that UK-PST has a better powerful mystery transmission charge than that of IK-PST for situations with each pairwise and organization customers

Synthesis, optical, structural, physical, and experimental gamma-ray transmission properties of high-density lead-boro-tellurite glasses: A multi-phases investigation towards providing a behavioral symmetry through Lead(II) oxide

We report the synthesis and multiple material properties of newly designed high-density lead-boro-tellurite glass system. The glass formulation as zPbO + [(100-z)(0.2B2O3 + 0.8TeO2)], where z: 10, 15, 20, and 25 mol%, were synthesized using a traditional melting technique around 625 to 725 °C. After successfully preparing the glass samples coded BT20-Pb10, BT20-Pb15, BT20-Pb20, and BT20-Pb25, some physical, structural, and optical analyses were included to serve up a broad understanding. BT20-Pb10, had a density of 5.4125 g/cm3, whilst BT20-Pb25 possessed a density of 6.0756 g/cm3. According to the XRD method, all samples except for BT20-Pb25 had an amorphous structure without any sharp peaks. Furthermore, the transmission percentage was in a decreasing trend parallel to the increasing PbO concentration. This phenomenon also influenced on energy bandgap values to reduce from 2.70 to 2.45 eV for BT20-Pb10 to BT20-Pb25 samples, respectively. In addition to the material characterizations, we studied experimental and theoretical radiation shielding properties. Using experimental methods, the photon absorption properties of the manufactured glasses were studied, and we found out that the BT20-Pb25 sample exhibited the highest MAC values among the compared glasses. Based on MAC findings, other essential parameters, such as HVL and Zeff, were found to be in enhancing way as PbO increased in the glass network. In the context of benchmarking of findings with theoretical and experimental results, it was clearly demonstrated that precise harmony reigns when all eight energy values are taken into account. To sum up, BT20-Pb25 may be regarded as a potential shielding glass for various applications in radiation fields owing to its significant material properties and shielding performance against energetic photons.

Equilibrium analysis of a peer-to-peer energy trading market with shared energy storage in a power transmission grid

With the increasing penetration of renewable energy resources in power systems, energy storage is expected to play a more active role in system regulation. Shared use of energy storage is an emerging business model, and its impact on the power grid needs thorough analysis. This paper proposes a two-layer equilibrium model to study the grid impact of peer-to-peer (P2P) energy trading considering shared energy storage (SES). The upper layer describes the P2P energy transaction among generators and SES units. The generators can freely choose to sell electricity to the SES units or power grid while the SES units can choose to charge or discharge. The physical power transmission grid is considered in the lower layer. It determines the locational marginal price through a real-time optimal power flow model. The locational marginal price in turn affects the decisions of generators and thus the equilibrium of the P2P market in the upper layer. Based on Karush-Kuhn-Tucker (KKT) optimality conditions and the Big-M method, a mixed-integer linear program is developed to compute the equilibrium of the P2P market in the upper layer, and an iteration algorithm is proposed to search the equilibrium point in the transmission grid with the P2P market. Numerical results demonstrate that both generators and SES units can benefit from the P2P energy transaction.

Scattering of water waves by two thin vertical barriers over shelf bottom topography

In this paper, water waves interaction with two thin vertical barriers over shelf bottom topography is analysed using linearised wave theory. The associated mixed boundary value problem is solved with the aid of method involving eigenfunction expansions of the velocity potential and orthogonality relation of the eigenfunctions. Further, the resulting system of algebraic equations is solved using the least square method to find the physical quantities, that is, reflection and transmission coefficients, free surface elevation and non-dimensional horizontal force experienced by the barriers. The energy balance relation is derived from Green's identity which ensures the correctness of the present results. The obtained results are also compared with the results available in the literature for validation purpose. With the help of different plots, the effect of depth ratios, length of the barriers, angle of incidence and gap between the barriers is investigated for various values of physical parameters. The study reveals that the phenomena of zero reflection, that is, full transmission can be avoided by using non-identical barriers or asymmetric shelf bottom topography. Also, it is highlighted that the presence of two barriers instead of a single barrier over shelf topography will help to reduce the transmitted wave energy near the seashore. A generalisation of number of surface piercing barriers over the shelf bottom topography is also demonstrated.

A tri‐level optimization strategy incorporating wind power against coordinated cyber‐physical attacks

AbstractWith the fast development of cyber‐physical power systems, coordinated cyber‐physical attacks have become one of the main threats to the security of modern power grid. Considering that it is difficult for attackers to obtain full information of the entire power grid, the coordinated cyber‐physical attack problem for partitioned power grid is studied in this paper, and a tri‐level defender‐attacker‐dispatcher optimization model with consideration of wind power uncertainty in a specific coordinated cyber‐physical attack mode is proposed. The Karush‐Kuhn‐Tucker (KKT) condition and an improved implicit enumeration algorithm are applied to obtain the solution of the complicated optimization problem effectively. In addition, two risk assessment indices pertinent to the physical lines and load measurements are proposed according to the obtained total amount of optimized load shedding and coordinated attack‐defense strategy under valid attack‐defense scenarios. Taking a partitioned IEEE 39‐bus test system as example, the risks of physical transmission lines and load measurements in different areas under attacks are elaborately studied, and the impact of wind power uncertainty on attack‐defense strategies is discussed as well. Numerical simulation results illustrate the effectiveness of the proposed optimization model and risk assessment indices, and some significant conclusions are drawn.