Transmission Medium Research Articles

Non-similar investigation of magnetohydrodynamics hybrid nanofluid flow over a porous medium with Joule heating and radiative effects

The aim of present article is to investigate the mixed convective magnetohydrodynamic (MHD) flow through non-similar modeling of hybrid nanofluid over a stretched surface with radiative effects. Nanofluids are considered a cutting-edge medium for energy transmission in the next generation, with outstanding thermodynamic features. The investigation of heat transfer on exponentially expanded sheets hold significant importance for researchers, given its broad range of applications in industries, manufacturing processes, and medical fields. In this study the flow is endorsed with the viscous dissipation, Joule heating and radiation impacts in the energy equation. In order to enhance the heat transfer, hybrid nanoparticles uniformly mixed with the base fluid. The differential equations emerged after the mathematical formulations are made non-dimensional via the non-similarity transformation up to the second order of iteration. To numerically simulate ordinary differential equations (ODEs), the MATLAB function bvp4c is employed. Key factors have been thoroughly mapped out in graphical form for easy comprehension. It is observed that when the strength of the Prandtl and Eckert number increases, the energy profile decreases, meanwhile temperature for expanding surface increases with an expansion in magnetic parameter. It is observed that the greater radiation quantities throughout the entire flux zone increase the thickness of the thermal boundary layer and the hydrodynamic temperature in the stretching situation. The increasing heat for expanding sheet causes fluid temperature to rise heat parameter, but the opposite consequences occur for shrinking sheet. The velocity reduces as the magnetic factor and the porosity parameter rises. The relevant engineering parameters, specifically the coefficient of skin friction and Nusselt number, have been documented in tabular form with respect to the significant factors mentioned earlier. The Nusselt coefficient decreases with an expansion in magnetic and the Ecker number. In accordance with the author's understanding, no previous work on the current model utilizing the local non-similarity method has been published. This discovery could help researchers who are interested in thermal power plants and solar energy storage. In limiting case, excellent agreement is found between present work and published article.

Unlocking mode programming with multi-plane light conversion using computer-generated hologram optimisation

Abstract Programmable optical devices provide performance enhancement and flexibility to spatial multiplexing systems enabling transmission of tributaries in high-order eigenmodes of spatially-diverse transmission media, like multimode fibre (MMF). Wavefront shaping with spatial light modulators (SLMs) facilitates scalability of the transmission media by allowing for channel diagonalization and quasi-single-input single-output operation. Programmable mode multiplexing configurations like multi-plane light conversion (MPLC) utilise the SLM and offer the potential to simultaneously launch an arbitrary subset of spatial tributaries in any N -mode MMF. Such programmable optical processor would enable the throughput of space-division multiplexing (SDM) systems to be progressively increased by addressing a growing number of tributaries over one MMF and in this way meet a growing traffic demand – similarly to the wavelength-division multiplexing evolution path. Conventionally, MPLC phasemasks are calculated using the wavefront matching algorithm (WMA). However, this method does not exploit the full potential of programmable mode multiplexers. We show, that computer-generated hologram algorithms like direct search enable significant improvement compared to the traditional WMA-approach. Such gains are enabled by tailored cost functions with dynamic constraints concerning insertion loss as wellas mode extinction ratio. We show that average mode extinction ratio can be greatly improved by as much as ≈ 15 dB at the expense of a small insertion loss35
deterioration of < 3 dB. One particular feature of programmable mode multiplexers is the adaptability to optimised transmission functions. Besides conventional LP modes transmission, we employ our approach on Schmidt modes, which are spatial eigenchannels with minimum crosstalk derived from a measured transmission matrix

Security and Reliability of Internet of Underwater Things: Architecture, Challenges, and Opportunities

The Internet of Underwater Things (IoUT) pertains to a system that utilizes technology of Internet of Things (IoT) for data collection, communication, and control in the underwater environment. The monitoring and management of various parameters in the underwater domain are gathered through the deployment of underwater sensors, communication devices, and controllers. It is crucial in emerging ocean engineering. However, due to the instability of the underwater environment and the particularity of the underwater communication transmission medium, it is vulnerable to security threats, which may damage the system or cause data errors. In this survey, we will discuss the challenges, solutions, and future directions of IoUT from security and reliability, respectively. To ensure the normal operation of IoUT, we analyze the underwater security problems and solutions of the IoUT. Then, we discuss the reliability issue and improved strategies of IoUT system in detail. Finally, we come up with our views about the theories, challenges, and future prospects of IoUT security after the comparative analysis.

Use of spectral transmittance model to improve the detection accuracy of chromium in soil

As a new quantitative analysis method for heavy-metal elements in soil, the main function of the polarization resolution model is to filter out the disturbance of other elements on the spectral signal of target plasma. In order to quantify the mechanism of improving detection performance, the spectral transmittance of plasma intensity in the polarization-resolved optical path has been derived, and the relationship between the intensity of polarization-resolved laser-induced breakdown spectroscopy (PRLIBS) and the characteristic peak wavelength has been defined. Using the spectral data in the wavelength range of 424.50–429.24 nm as the characteristic signal, a quantitative analysis method for detection of the Cr element in soil has been developed. The improvement of spectral intensity stability at the characteristic peak of Cr I 425.7 was analyzed, and the mechanism of enhancing the detection accuracy was elucidated. Research has shown that, based on the polarization characteristics of Cr element plasma, PRLIBS is not affected by the matrix effects of soil and characterizes the amplitude conversion from the reference concentration of Cr element to the plasma spectral intensity. The spectral transmittance of plasma spectra depends not only on the characteristic peak wavelength and complex refractive index of heavy-metal elements but also on the measurement conditions such as spatial geometric angles and reflectivity of the transmission medium.

Corti fluid is a medium for outer hair cell force transmission.

The mammalian cochlea amplifies sounds selectively to improve frequency resolution. However, vibrations around the outer hair cells (OHCs) are amplified non-selectively. The mechanism of the selective or non-selective amplification is unknown. This study demonstrates that active force transmission through the extracellular fluid in the organ of Corti (Corti fluid) can explain how the cochlea achieves selective sound amplification despite the non-frequency-selective action of OHCs. Computational model simulations and experiments with excised cochleae from young gerbils of both sexes were exploited. OHC motility resulted in characteristic off-axis motion of the joint between the OHC and Deiters cell (ODJ). Incorporating the Corti fluid dynamics was critical to account for the ODJ motion due to OHC motility. The incorporation of pressure transmission through the Corti fluid resulted in three distinct frequency tuning patterns depending on sites in the organ of Corti. In the basilar membrane, the responses were amplified near the best-responding frequency (BF). In the ODJ region, the responses were amplified non-selectively. In the reticular lamina, the responses were amplified near the BF but suppressed in lower frequencies. The suppressive effect of OHCs was further examined by observing the changes in tuning curves due to local inhibition of OHC motility. The frequency response of the reticular lamina resembled neural tuning, such as the hypersensitivity of tuning-curve tails after hair cell damage. Our results demonstrate how active OHCs exploit the elastic frame and viscous fluid in the organ of Corti to amplify and suppress cochlear vibrations for better frequency selectivity.Significance Statement Active outer hair cells have been considered to selectively amplify the basilar membrane vibrations near the sound's tonotopic location. However, recent observations from different labs showed that outer hair cells' action is non-selective-it spreads over the broad span of traveling waves. These observations challenge the existing theory pegged to basilar-membrane mechanics. The motion at the joint between the outer hair cell and the Deiters (ODJ) cell holds the key to account for the non-selective action of outer hair cells. We show that the characteristic motions at the ODJ are explained coherently when Corti fluid acts as the medium for outer hair cell force transmission. Our results demonstrate how non-selective outer hair cell action produces selective neural responses.

Study on the Spatio-temporal Evolutionary Properties of Gas-liquid Two-phase Flow in Centrifugal Pump as Turbine (PAT)

With the increasing complexity of the industrial production process, the transmission medium of the hydraulic turbine is no longer satisfied, and the gas-liquid two-phase mixed medium has to be considered. The presence of gas in the transmission medium will alters the internal flow structure of the hydraulic turbine and affect its operational stability. Therefore, for the purpose of clarifying the influence of inlet gas content on the internal flow of PAT, the unsteady flow of the PAT is simulated in this paper using numerical simulation. Based on the numerical simulation results, the influence of inlet gas content on the internal flow characteristics, characteristics of pressure fluctuation in impeller and volute, and vortex evolution of flow field are analyzed. The accumulation of gas phase leads to the emergence of vortices, and regions with low pressure values appear at the vortex generation. The major factor of the periodic variation of pressure fluctuation between volute and cut-water is the dynamic and static interference of impeller. The increase of gas content causes more flow disorder in the cut-water region and the volute contraction section. Since the gas in the flow channel is predominantly on the suction side of blades, the flow field on the suction side is more complex than that on the pressure side, and the amplitude of pressure fluctuation increases appropriately. The vortex structure is mainly distributed on balance hole, inlet area of impeller and suction side of blade. As the blade rotates, there are new shedding and growth of vortices, and finally attached to the volute wall. Increasing gas content enhances the influence of blade rotation on the vortex evolution characteristics in the volute and impeller.

Low-Cost IoT-Based Sensors Dashboard for Monitoring the State of Health of Mobile Harbor Cranes: Hardware and Soft-ware Description

A cost-effective IoT-based real-time data acquisition and analysis hardware system was developed to enhance the performance of the mobile harbor cranes using a combination of a cost-effective quality control monitoring sensor dashboard (proximity sensors, angle position sensor, weight sensor, vibration sensor, and wind sensor), embedded microcontroller (Arduino), and embedded computer (Raspberry Pi). Hardware was operated using a specially developed novel Quality Control and Data Acquisition Multiprocessing software (QC-DAS). The QC-DAS can automatically collect and save real-time data of the sensors in a large-capacity SD card, monitor the state of health of the hardware, and transmit the real-time data of the sensors and the working state of the crane to an IoT server. The novelty of the QC-DAS design is that each function is encapsulated in a predefined module that is "immersed" in a message transmission medium. Modules interact by sending and receiving various signals through this medium. Modularity makes system design simpler, faster, and flexible. Thanks to modularity, users may incorporate their data processing modules when new sensors are added to match the system's needs. Thanks to modularity the DC-DAS can operate quality control hardware for any mobile cranes. There are several constraints in the quality control data acquisition system used by the Damietta Port Authority in Damietta, Egypt, SESCO TRANS company which cause the loading and unloading process to be slowed down. As a result, the SESCO TRANS company upgraded its quality control data acquisition system using the QC-DAS. The hardware was deployed for six months, during which the collected data was used to verify the crane's performance. The vibration produced by the slewing of the crane was monitored and compared with the bearing fault frequency limits, during the operation the wind speed was monitored and compared with the critical wind speed to stop the crane operation automatically, and the payloads data of the six months was collected and was used to calculate the working efficiency of the load and unload process of the crane. The results demonstrated that while maintenance costs were decreased, the crane load/unload procedure was improved. The SESCO TRANS company crane operators approved the developed approach and appreciated the achieved results.

Biometric Steganography Using Mid Position Value Technique

Abstract: Biometric data, is prone to attacks and threats from cyber criminals to conduct identity theft, and its economic value makes it a product that can be traded in underground marketplaces such as the dark web. Securing it is the need of the hour. Sensitive data is subsequently in danger throughout a biometric identification system, and therefore the security measures implemented to guard this data must cover all contingencies. A steganographic approach is proposed as a solution to this. Biometrics are hidden inside other biometrics for safe storage and secure transmission. Steganography is a process of hiding data in a transmission medium. The main objectives while hiding data are its undetectability, robustness against image processing and other attacks, which steganography can easily achieve. This project focuses on a process of hiding an image in another image by using mid position value(mpv) technique. Here we have to choose the secret biometric on which Arnold transform will be applied resulting in a scrambled version of the secret biometric. This will be embedded into the cover image resulting in a stego image. Lastly, the hidden secret biometric will be decoded from this stego image, which will first result in a scrambled secret biometric. Inverse Arnold Transform will be applied on this to finally result in the decoded secret biometric.

Leaky Feeder as A VoIP Transmission Medium

VoIP (Voice over Internet Protocol) is a technology that allows its user to transmit voices using an internet network, although the technology uses the internet as its transmission medium VoIP still uses cable for most of its applications resulting in complicated cable management if not managed properly, this method can be optimized via wireless transmission for more efficient mobility and system configuration. This research aims to find out the capabilities of Leaky Feeder cable as a medium for VoIP transmission. A leaky feeder system consists of a single cable that runs along its designated space. This cable has gaps that allow the radio signal to leak into or out of the cable along its entire length meaning it can cover a larger area than the usual point-to-point transmission using cable. The parameters observed in particular are Signal Strength, Bit Rate, Packet Loss, Delay, and Throughput, the data obtained is taken quantitatively and its average value is calculated to ensure the system efficiency. Signal Strength trial shows an average value of -60.25 dBm, while also having an uplink and downlink of each 14.86 Mbps and 12.79 Mbps, Bit Rate trial shows that the more clients are served the less bandwidth each client will have , The Packet Loss trial shows an outstanding 0.71% loss, the delay trial shows an average of 20.5ms delay with -40dbm signal quality, and finally Throughput trial shows the highest value at 388Kbps when performing one call with -65dbm signal quality . This shows that the application of Leaky Feeder cable use on VoIP transmission is in a good category. Using Leaky Feeders in buildings can also reduce the number of Access Point installations required to cover the same area.

Digital watermarking algorithm for QR code based on hybrid PSOGWO optimization

Abstract With the rapid development of digital media, QR codes have become widely used as an important medium for information transmission. However, this also presents serious security challenges, such as frequent image infringement and inevitable compression and scaling issues during data transfer. These challenges directly threaten the effectiveness and integrity of image information, and effective protection measures must be taken. Under this background, digital watermarking technology comes into being as an innovative method to enhance security. This paper presents an innovative Hybrid Particle Swarm Optimization and Gray Wolf optimization (HPG) algorithm, which combines the advantages of PSO and overcomes the limitations of traditional GWO algorithm. The algorithm is further improved by using Bernoulli chaotic mapping and nonlinear convergence factor. The experiments focus on the global and local search balance of the algorithm and its ability to resist repeated scaling attacks. The results show that the nonlinear convergence factor of HPG algorithm slows down the iteration speed at the initial stage, strengthens the global search, and avoids falling into the local optimal. In the later stage, the iteration is accelerated to improve the local search speed and convergence efficiency, thus optimizing the performance of the algorithm and ensuring the safety and quality of image information. In addition, the algorithm has better performance in balancing imperceptibility and robustness of digital watermarking, and its peak signal-to-noise ratio (PSNR) is higher. Even with many scaling iterations, the normalized correlation (NC) value is still close to 1. Compared with the existing typical algorithms, HPG algorithm is more robust to repeated scaling attacks.

Physics-Driven Image Dehazing from the Perspective of Unmanned Aerial Vehicles

Drone vision is widely used in change detection, disaster response, and military reconnaissance due to its wide field of view and flexibility. However, under haze and thin cloud conditions, image quality is usually degraded due to atmospheric scattering. This results in issues like color distortion, reduced contrast, and lower clarity, which negatively impact the performance of subsequent advanced visual tasks. To improve the quality of unmanned aerial vehicle (UAV) images, we propose a dehazing method based on calibration of the atmospheric scattering model. We designed two specialized neural network structures to estimate the two unknown parameters in the atmospheric scattering model: the atmospheric light intensity A and medium transmission t. However, calculation errors always occur in both processes for estimating the two unknown parameters. The error accumulation for atmospheric light and medium transmission will cause the deviation in color fidelity and brightness. Therefore, we designed an encoder-decoder structure for irradiance guidance, which not only eliminates error accumulation but also enhances the detail in the restored image, achieving higher-quality dehazing results. Quantitative and qualitative evaluations indicate that our dehazing method outperforms existing techniques, effectively eliminating haze from drone images and significantly enhancing image clarity and quality in hazy conditions. Specifically, the compared experiment on the R100 dataset demonstrates that the proposed method improved the peak signal-to-noise ratio (PSNR) and structure similarity index measure (SSIM) metrics by 6.9 dB and 0.08 over the second-best method, respectively. On the N100 dataset, the method improved the PSNR and SSIM metrics by 8.7 dB and 0.05 over the second-best method, respectively.

Demodulating Optical Wireless Communication of FBG Sensing with Turbulence-Caused Noise by Stacked Denoising Autoencoders and the Deep Belief Network

Free-space optics communication (FSO) can be used as a transmission medium for fiber optic sensing signals to make fiber optic sensing easier to implement; however, interference with the sensing signals caused by the optical turbulence and scattering of airborne particles in the FSO path is a potential problem. This work aims to deep denoise sensed signals from fiber Bragg grating (FBG) sensors based on FSO link transmission using advanced denoising deep learning techniques, such as stacked denoising autoencoders (SDAE). Furthermore, it will demodulate the sensed wavelength of FBGs by applying the deep belief network (DBN) technique. This is the first time the real FBG sensing experiment has utilized the actual noise interference caused by the environmental turbulence from an FSO link rather than adding noise through numerical processing. Consequently, the spectrum of the FBG sensors is clearly modulated by the noise and the issue with peak power variation. This complicates the determination of the center wavelengths of multiple stacked FBG spectra, requiring the use of machine learning techniques to predict these wavelengths. The results indicate that SDAE is efficient in denoising from the FBG spectrum, and DBN is effective in demodulating the central wavelength of the overlapped FBG spectrum. Thus, it is beneficial to implement an FSO link-based FBG sensing system in adverse weather conditions or atmospheric turbulence.

Using TED talks to improve engineering students’ oral skills

This paper deals with the training of undergraduate engineering students and is interdisciplinary in nature. It brings together three distinct aspects of scientific dissemination: the content of an engineering degree; the oral transmission of this content following the effective TED talks model; and the use English as a medium of scientific transmission. The paper highlights the need for trainee Spanish engineers to be able to communicate their work to the public through oral presentations that are brief and entertaining, yet scientifically rigorous. The core of the study consists of an analysis of a particular TED talk that is relevant for a variety of engineering degrees. We conclude that while it is necessary for Spanish engineers to receive specific training at a professional level in oral communication skills, there is a close relationship between the mode of transmission and the subject specific content to be transmitted that needs to be considered carefully. Developing a mastery of English is important, but essential communication skills are the most crucial aspect, regardless of the language of communication.

Intergenerational Transmission of Wisdom Through Family Narratives: A Qualitative Analysis of Emerging Adults' Perspective

Family narratives are a medium for the intergenerational transmission of life wisdom, which may influence recipient’s beliefs system and behaviors. Despite a growing body of knowledge on wisdom, emerging adults remain insufficiently researched as to what wisdom from their perspective was conveyed to them through stories. The aim was to identify what wisdom emerging adults perceive in the narratives told them by their parents about themselves. The study was conducted in Poland. Convenience sampling was used. 42 emerging adults (33 female, 8 male, 1 non-binary) ranging from 19 to 22 years participated in the study. Participants were asked to write stories about their parents, separately, about mother and father when they were young. These were supposed to be stories both containing wisdom and told them by their parents. Then they were asked to describe what wisdom was contained in the recalled story and what they learned from it. Data was analyzed using thematic analysis. Twelve participants were not able to recall a story about one of their parents. They completed one part of the written task and explained the reasons for not knowing the story about the other. These responses were included in the analysis. The thematic analysis identifies the following main themes: transmission of life lessons, transmission of values, family myths, forms of wisdom transmitting. The wisdom read by emerging adults from the recalled stories took the form of advice, encouragement, warning and reprimand. They were usually expressed indirectly. It required effort to read the hidden message and give it meaning. The study showed the importance of family stories in the upbringing process and preparation for adulthood. In the face of the following changes in lifestyles and family communication, the results may be used to support and educate families in deepening intra-family relationships.

Experimental Study on Improving the Recovery Rate of Low-Pressure Tight Oil Reservoirs Using Molecular Deposition Film Technology

The intricate geological characteristics of tight oil reservoirs, characterized by extremely low porosity and permeability as well as pronounced heterogeneity, have led to a decline in reservoir pressure, substantial gas expulsion, an accelerated decrease in oil production rates, and the inadequacy of traditional water injection methods for enhancing oil recovery. As a result, operators encounter heightened operational costs and prolonged timelines necessary to achieve optimal production levels. This situation underscores the increasing demand for advanced techniques specifically designed for tight oil reservoirs. An internal evaluation is presented, focusing on the application of molecular deposition film techniques for enhanced oil recovery from tight oil reservoirs, with the aim of elucidating the underlying mechanisms of this approach. The research addresses fluid flow resistance by employing aqueous solutions as transmission media and leverages electrostatic interactions to generate nanometer-thin films that enhance the surface properties of the reservoir while modifying the interaction dynamics between oil and rock. This facilitates the more efficient displacement of injected fluids to replace oil during pore flushing processes, thereby achieving enhanced oil recovery objectives. The experimental results indicate that an improvement in oil displacement efficiency is attained by increasing the concentration of the molecular deposition film agent, with 400 mg/L identified as the optimal concentration from an economic perspective. It is advisable to commence with a concentration of 500 mg/L before transitioning to 400 mg/L, considering the adsorption effects near the well zone and dilution phenomena within the reservoir. Molecular deposition films can effectively reduce injection pressure, enhance injection capacity, and lower initiation pressure. These improvements significantly optimize flow conditions within the reservoir and increase core permeability, resulting in a 7.82% enhancement in oil recovery. This molecular deposition film oil recovery technology presents a promising innovative approach for enhanced oil recovery, serving as a viable alternative to conventional water flooding methods.

Implementation of Optical Coherent Communication System between Two Computers

This work represents implementation and investigation of optical coherent communication system between two computers. A single mode optical fiber is selected as transmission medium. The data are sent via the RS-232 standard interface with a bit rate of 9.6 kbps from personal computer (PC1) by line receive to convert the data from electrical levels (-12/+12 V) into TTL level (0/5 V). The modulation of this data was accomplished by internal modulation using laser diode type (HFCT-5208M) 1310 nm wavelength. The optical D-coupler was used to combine the optical signal that come from laser source with optical signal of laser local oscillator (OTS-304XI) at 1310/1550 nm wavelength to obtain coherent (homodyne and heterodyne) detection respectively. A PIN photodetector (HFCT-5208M) is used. Calculations of Signal to Noise Ratio (SNR) and Bit Error Rate (BER) for coherent detection were measured at different length of the optical fiber. Result show that high SNR and low BER for heterodyne detection than for homodyne detection.

Changes in composition and concentration of differential metabolites in root exudates are associated with aluminum-tolerance of Ricinus communis under a high CO2 environment

Root exudates are the most direct performance for plants responding to adverse environments, and are also important media for materials exchange, energy transmission and information communication between the roots and rhizosphere. However, how plant roots and exudates respond to aluminum (Al) stress under elevated CO2 concentration (eCO2) is still unclear. Ricinus communis is a famous oilseed crop throughout the world, which has strong tolerance to metal contaminated soil. In the present study, root physiological changes and the exudates of this species under aluminum stress and eCO2 based on metabolomic were investigated. The results showed that high Al concentration stress significantly increased aluminum, MDA, proline, and soluble sugar contents, and decreased the dry weights and soluble protein concentration. Furthermore, eCO2 alleviated the inhibition of root growth under high Al stress by increasing the dry weights, antioxidant enzyme activities and decreasing the MDA content. Collectively, a total of 511 metabolites were detected in the castor exudates of which lipids, organic acids, and organic oxygen compounds occupied 40.82%, 17.78% and 12.54%, respectively. There were 83, 15, and 100 differential metabolites for high Al stress, eCO2 and the interaction of the two factors compared with the control. 12 differential metabolites were found under eCO2 and Al stress compared with Al stress alone. Under Al stress, TCA cycle, organic acids, and lipids metabolisms were inhibited; coumarins and carbohydrates conjugates were significantly up-regulated, which may help castor adapt to aluminum-contaminated conditions. Moreover, eCO2 increased the secretion of organic acids, fatty acyls, and carbohydrates to enhance the antioxidant capacity and root growth of castor under Al stress; eCO2 enhanced the TCA cycle, organic acids accumulation, lipids metabolism, biosynthesis of amino acids, pentose and glucuronate interconversions, and inhibited DNA oxidative stress of castor roots under Al stress. The present study provides new insights into the crucial role of root exudates in improving Al-tolerance of castor under eCO2.

Research on Ultrasonic Guided Wave Pipeline Defect Detection Method Based on Modal Analysis

Abstract Pipelines are important transmission media in the petroleum industry, and their safe and stable operation is of great significance to industrial safety. The secure and reliable operation of oil and gas pipelines holds paramount importance for industrial safety. The significance of non-destructive testing (NDT) technology in this context is steadily growing. Presently, guided wave-based pipeline defect detection technology has garnered considerable attention. This method is noteworthy for its extensive coverage, ability to inspect the entire cross-section, and its capability to conduct inspections without disrupting ongoing production processes. Research focused on the displacement distribution of various modes of guided waves, exploring different excitation methods for each mode. The investigation also delved into the interaction mechanism between guided waves and pipeline defects; Conducted research on the detection of axial, circumferential and radial dimensions of defects using different modes of guided waves, and carried out experimental verification, studying the transformation law of the reflection coefficient of the defect reflection echo when the flaw size changes provide a reference for pipeline defect detection based on guided waves.

Time-Varying Cypher Assignment Based on Secrecy Capacity

Wireless communication is a convenient but not secure transmission media. For internet application, such as E-commerce, there are a lot of private information existed. To protect the secret information inside and to set up a secure communication becomes an urgent topic. The purpose of a perfect communication system is to ensure the authentic destination could correctly and successfully receive the exact desired information from the transmitter. Also, the system with authorization and authentication could protect the transmitted information away from the eavesdroppers. Generally, the encryption scheme is applied to. Although these methods have been employed in the system for the security, those unexpected and advanced attackers have been continuously developing. Error-free cryptogram based on Shannon’s theorem could provide a solution for the information security. It could be implemented with physical-layer security coding scheme. In this paper, the cypher generator is proposed with physical-layer coding scheme. The cypher format includes two parts. One is the prefixed code and the other is error-control code. The major purpose of prefixed code is the key to find the position indexing of code in the cypher. In this cypher generator, the interleaver plays a role to disturb the original data. It increases the degree of difficulty to break the cypher. With cryptanalysis, the practical example of LDPC is given. With AI technology, the advanced algorithm might be developed for cypher coding and decoding.

The fuzzy system ensembles entomological, epidemiological, demographic and environmental data to unravel the dengue transmission risk in an endemic city

BackgroundThe effectiveness of dengue control interventions depends on an effective integrated surveillance system that involves analysis of multiple variables associated with the natural history and transmission dynamics of this arbovirus. Entomological indicators associated with other biotic and abiotic parameters can assertively characterize the spatiotemporal trends related to dengue transmission risk. However, the unpredictability of the non-linear nature of the data, as well as the uncertainty and subjectivity inherent in biological data are often neglected in conventional models.MethodsAs an alternative for analyzing dengue-related data, we devised a fuzzy-logic approach to test ensembles of these indicators across categories, which align with the concept of degrees of truth to characterize the success of dengue transmission by Aedes aegypti mosquitoes in an endemic city in Brazil. We used locally gathered entomological, demographic, environmental and epidemiological data as input sources using freely available data on digital platforms. The outcome variable, risk of transmission, was aggregated into three categories: low, medium, and high. Spatial data was georeferenced and the defuzzified values were interpolated to create a map, translating our findings to local public health managers and decision-makers to direct further vector control interventions.ResultsThe classification of low, medium, and high transmission risk areas followed a seasonal trend expected for dengue occurrence in the region. The fuzzy approach captured the 2020 outbreak, when only 14.06% of the areas were classified as low risk. The classification of transmission risk based on the fuzzy system revealed effective in predicting an increase in dengue transmission, since more than 75% of high-risk areas had an increase in dengue incidence within the following 15 days.ConclusionsOur study demonstrated the ability of fuzzy logic to characterize the city’s spatiotemporal heterogeneity in relation to areas at high risk of dengue transmission, suggesting it can be considered as part of an integrated surveillance system to support timely decision-making.