Hybrid absorbing boundary condition based on transmitting boundary and its application in 3D fractional viscoacoustic modeling

An accurate numerical simulation for wave equations is essential for understanding of wave propagation in the earth's interior as well as full waveform inversion and reverse time migration. However, due to computational cost and hardware capability limitations, numerical simulations are often performed within a finite domain. Thus, an adequate absorbing boundary condition (ABC) is indispensable for obtaining accurate numerical simulation results. In this study, we develop a hybrid ABC based on a transmitting boundary, which is referred to as THABC, to eliminate artificial boundary reflections in 3D second-order fractional viscoacoustic numerical simulations. Furthermore, we propose an adaptive weighted coefficient to reconcile the transmitting and viscoacoustic wavefields in THABC. Through several numerical examples, we determine that the proposed THABC approach is characterized by the following benefits. First, with the same number of absorbing layers, THABC exhibits a better ability in eliminating boundary reflection than traditional ABC schemes. Second, THABC is more effective in computation, since it only requires the wavefields at the current and last time steps to solve the transmitting formula within the absorbing layers. Benefiting from a simple but effective combination between the transmitting equation and the second-order wave equation, our scheme performs well in the 3D fractional Laplacian viscoacoustic numerical simulation.

Partial transmitting sequence method based on trellis factor search

To obtain good trade-offs between complexity and performance onpeak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM)using partial transmitting sequence (PTS) schemes, a trellis structure based PTS factor searchmethod is proposed. The trellis search is with a variant constraint length L_C, 1 ≤ L_C ≤ V-1,where V is the number of PTS subblocks. The method is to decide a PTS factor by searching all thepossible paths obtained by varying L_C consecutive factors. The trellis search can be viewed as ageneral PTS factor search model. If L_C = V-1, it is a full search, and if L_C = 1, it is aniterative search. Using different constraint lengths, trellis factor search PTS exhibits differentPAPR reduction performances. A larger L_C results in a better performance and L_C = V-1 results inthe optimum. However, a larger L_C requires more computation. This helps to choose a good trade-offbetween complexity and performance.

FINITE ELEMENT-ARTIFICIAL TRANSMITTING BOUNDARY METHOD FOR WAVE SCATTERING FROM IRREGULAR CYLINDER

The finite element artificial transmitting boundary method is employed here to treat the near field scattering of a cylindrical wave from an irregular cylinder. A comparison is made between this method and the analytical one. And then examples are given to demonstrate the solution of several problems of the irregular object scattering. The method can not only produce clear physical pictures, but can efficiently handle many complicated scattering problems.

Time-Domain Analysis of Underground Station-Layered Soil Interaction Based on High-Order Doubly Asymptotic Transmitting Boundary

Based on the modified scale boundary finite element method and continued fraction solution,a high-order doubly asymptotic transmitting boundary(DATB)is derived and extended to the simulation of vector wave propagation in complex layered soils.The high-order DATB converges rapidly to the exact solution throughout the entire frequency range and its formulation is local in the time domain,possessing high accuracy and good efficiency.Combining with finite element method,a coupled model is constructed for time-domain analysis of underground station-layered soil interaction.The coupled model is divided into the near and far field by the truncated boundary,of which the near field is modelled by FEM while the far field is modelled by the high-order DATB.The coupled model is implemented in an open source finite element software,OpenSees,in which the DATB is employed as a super element.Numerical examples demonstrate that results of the coupled model are stable,accurate and efficient compared with those of the extended mesh model and the viscous-spring boundary model.Besides,it has also shown the fitness for long-time seismic response analysis of underground station-layered soil interaction.Therefore,it is believed that the coupled model could provide a new approach for seismic analysis of underground station-layered soil interaction and could be further developed for engineering.

Image Processing Technology of Flaws within Infrared Transmitting Glasses

We investigated image processing algorithms of the original infrared glass flaw image. Using the Laplacian edge enhancement following LSD （Line Segment Detector） algorithm, we can get a good flaw image very consistent with the original one. This study is very helpful to further enhance the infrared glass flaw inspection technique.

Assessment Model of Atmosphere Transmitting Influence on High-resolution Airborne SAR Stereo Positioning

The influence derived from atmosphere transmitting of radar wave, in the application of high-resolution airborne Synthetic Aperture Radar (SAR) stereo positioning, may produce some phase errors, and eventually be introduced into positioning model. This paper described the principle of airborne SAR stereo positioning and the error sources of stereo positioning accuracy that arose from atmosphere transmitting, established a corresponding assess- ment model of atmosphere transmitting influence, and testified the model and the assessment principle taking the 1-m resolution airborne SAR images of Zigong City, Sichuan Province in China, as the test dataset. The test result has proved that the assessment model is reliable and reasonable. And, it has shown that the phase error arisen from time delay is the main error source during the atmosphere transmitting, which has much more influences on cross-track di- rection and introduces a stereo positioning error of about eight meters, but less on the along-track direction.

Experimental Investigation of Transmitting Properties of Acoustic Emission Signal and Its Application

The transmitting properties of acoustic emission(AE) signal is investigated in order to provide experimental basis for application of AE technique. In the paper, the influences of the geometric shape and material properties of the mediums and the bearing type on AE transmission are analyzed for providing the theoretic foundation for selecting the transmission route of AE signal and the fixing location of the AE sensor reasonably. According to the transmitting properties of AE, an apparatus of detecting AE signal for the tool breakage monitoring system has been set up. Its application results show that it is of benefit to improving the sensitivity of the tool breakage monitoring system.

The Source and Observation System of Binchuan Earthquake Signal Transmitting Seismic Station and Its Preliminary Observation Results

This paper summarizes the basic situation of the Binchuan Transmitting Seismic Station and the geophysical observations of the area where it is located,with a focus on the constitution of the observation system of the transmitting seismic station,the excitation characteristics and propagation distance of signals excited by the airgun source in the reservoir and well. The paper also summarizes and discusses on the results of the observations and problems encountered since the Transmitting Seismic Station was built.Finally,this paper proposes the main research to be carried out on the basis of the project aims.

Research on the Novel Mode of Plane Graphic Design from the Angle of Visual Language Transmitting

In this paper, we conduct research on the novel mode of plane graphic design from the core angle of the primary visual language transmitting. Relationship between nationality and cosmopolitan processing in graphic design in the design of image symbol expression and significance of the symbol on the one hand require symbolic form must have enough openness and the cognitive function on the other hand with semiotics method can let the designer to extract the most representative and symbolic notation style to carry on the design expression. As a non- verbal symbols, from the perspective of the view, the design image is no national boundaries, but the human form to beauty and should express the symbolism of cognition is the same. In the form of the ethnic groups of the cosmopolitan codes are for identification of Chinese contemporary design possible effective methods. Our research proposes novel perspective of the design which is meaningful.

The immune system:uncharted pathways between senses and the brain

Humans and animals use the classic five senses-sight,hearing,touch,smell,and taste-to detect and monitor their environment,with the sense of position and movement often referred to as the sixth sense.The perception of external signals through the senses is essential to an organism's survival,transmitting signals to the central nervous system(CNS)and prompting physiological changes in other biological systems.In addition to the direct effects of sense-induced mediators in the brain.

Experimental study on pulse radar target probing in RFS based on interrupted transmitting and receiving

Radar target probing and measurement are challenging tasks for Radio Frequency Simulation（RFS） with pulse radar signal. Due to the long-time duration of pulse radar signal and the limited space of anechoic chamber, the reflected signal returns before pulse radar signal is fully transmitted in RFS. As a consequence, the transmitted and reflected signals are coupled at the receiver. To handle this problem, the Interrupted Transmitting and Receiving（ITR） experiment system is constructed in this paper by dividing the pulse radar signal into sub-pulses. The target echo can be obtained by transmitting and receiving the sub-pulses intermittently. Furthermore, the principles of ITR are discussed and the target probing experiments are performed with the ITR system. It is demonstrated that the ITR system can overcome the coupling between the reflected and transmitted signals. Based on the target probing results, the performance of pulse radar target probing and measurement can be verified in RFS with the ITR system.

Transmit Power Minimization for IRS-Assisted NOMA-UAV Networks

The flexibility of unmanned aerial vehicles(UAVs)allows them to be quickly deployed to support ground users.Intelligent reflecting surface(IRS)can reflect the incident signal and form passive beamforming to enhance the signal in the specific direction.Motivated by the promising benefits of both technologies,we consider a new scenario in this paper where a UAV uses non-orthogonal multiple access to serve multiple users with IRS.According to their distance to the UAV,the users are divided into the close users and remote users.The UAV hovers above the close users due to their higher rate requirement,while the IRS is deployed near the remote users to enhance their received power.We aim at minimizing the transmit power of UAV by jointly optimizing the beamforming of UAV and the phase shift of IRS while ensuring the decoding requirement.However,the problem is non-convex.Therefore,we decompose it into two sub-problems,including the transmit beamforming optimization and phase shift optimization,which are transformed into second-order cone programming and semidefinite programming,respectively.We propose an iterative algorithm to solve the two sub-problems alternatively.Simulation results prove the effectiveness of the proposed scheme in minimizing the transmit power of UAV.

A Survey of Digital Content Required for STD Prevention Education Taught by School Nurses

Purpose: In recent years, there has been concern in Japan about the increase in STDs among adolescents aged 15 - 19. In order to prevent STDs and guide adolescents toward desirable sexual behavior, this study’s goal was to examine the actual state of STD prevention education taught by school nurses as part of the school curriculum, as well as the kinds of digital content they wish to have for teaching on the subject. Method: An anonymous, self-administered questionnaire was distributed by email and leaflet. Targeting the 100 valid responses received from the surveyed school nurses, descriptive statistics were made for each survey item and comparisons were made between the early- and mid-career groups based on years of experience. Results: 70.0% of respondents reported teaching about STDs in Health & Physical Education classes. School nurses in the early-career group used ready-made materials, while the mid-career group used both ready-made and self-made materials. 95% of respondents reported that they had little or no knowledge of STDs, while 84% reported that they were “good” or “fairly good” at teaching classes on sexuality. Both groups reported difficulty with the topics of “phimosis” and “nocturnal emissions” in the physiological category, “sexual behavior” in the “sex-adjacent” category, and “sexual and reproductive issues” in the psychosocial category. Respondents expressed a need for digital content covering the topics of “sexual violence”, “sexual abuse”, “sexually transmitted diseases”, and “how to turn down sex”. The mid-career group desired digital content for more items than the early-career group, with significant differences in the pathogens involved in sexually transmitted diseases and sex-adjacent items. 32.0% of respondents answered that they had done self-study for sex education classes in the past three years, and both groups desired self-study on “sexually transmitted diseases”, with the mid-career group significantly higher than the early-career group on “cervical cancer & HPV”, “emergency contraceptives”, and “media literacy”. Conclusion: Health & Physical Education is the main subject that covers STDs, and pre-existing materials are commonly used. It is expected that this is due to nurses’ busy schedules and the fact that only one school nurse is assigned to each school. The data collected suggested that nurse teachers want categorized digital content that can be used in the classes they are responsible for, rather than educational content on topics they are not comfortable with. In addition, given the changing environment surrounding sex, it was clear that they wish to understand the realities and needs of the high school students they teach, and desire self-study opportunities to improve their teaching methods.

Parents’s knowledge and awareness about hepatitis B can influence the vaccination of their children

BACKGROUND Birth-dose(Hep-BD)followed by three additional doses(Hep-B3)of hepatitis B virus(HBV)vaccine are key to eliminating HBV by 2030.Unfortunately,Hep-BD and Hep-B3 coverage in our country is poor.AIM To studied the parent’s knowledge and awareness about HBV infection,its prevention,consequences and vaccination.METHODS Parents of 6 months to 8 years old children were interviewed to assess their knowledge&awareness about hepatitis B,its transmission,prevention,illness caused by this,and vaccination.Eighteen close-ended questions were admini-stered,and responses were recorded as‘yes’,‘no’,or‘not sure’.HBV knowledge score was calculated based on the sum of correct answers.Each correct response scored one point and incorrect,missing or‘not sure’responses received no points.Categorical data are presented as number(%)and numerical data are expressed as median.Data were compared using Chi2 tests and level of significance was kept as P<0.05.RESULTS Parents(58.3%mothers)of 384 children(89.9%age<5 years;82%age-appropriately vaccinated)were included.Three hundred and twenty-two(83.9%)children were Hep-B3 vaccinated.94.3%,87.5%,and 29.2%parents knew about polio,tetanus,and hepatitis B vaccine.Overall,41.2%,15.8%,and 23%parents knew about hepatitis B transmission,consequences of infection,and prevention respectively.Only 7.6%parents knew about three-dose schedule of hepatitis B vaccination.Only 23%parents believed that vaccine could prevent HBV,15.7%knew that HBV affects liver.Parents of Hep-B3 vaccinated children were significantly more aware about HBV than the parents of unvaccinated children(P<0.05 for 17/18 questions).CONCLUSION The knowledge and awareness among the parents about hepatitis B is poor.The Increasing knowledge/awareness about HBV among parents may improve Hep-B3 vaccination coverage.

Seroprevalence Survey of HIV and Hepatitis B Virus and Behavioral Characteristics among Heavy Truck Drivers along Port Sudan-Khartoum Highways

The prevalence of human immunodeficiency virus (AIDS) and hepatitis B virus among heavy truck drivers and their assistants has been well documented globally in correlation with their behavioral characteristics. The present study aimed to screen for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and behavioral characteristics among heavy truck drivers in Port Sudan. A cross-sectional study was conducted on 274 heavy truck drivers and their assistants who used the highway Port Sudan-Khartoum in Port Sudan city during 2019-2021. Data on behavioral characteristics and substance use habits were collected using a structured questionnaire, and an ELISA test was used to screen for HIV and HBV infections in the study participants. The chi-square test, odds ratio, and confidence intervals were used to find the association between behavioral characteristics and seropositive HIV/HBV. Of the 274 enrolled participants, the seroprevalence rates of HIV were 2.7% and HBV was 23.7%. Ninety-four (34.3%) of them had a history of high-risk sexual behavior outside of marriage;only two (0.7%) used condoms;14.2% of participants reported alcohol use;and 1.1% reported drug use. Univariate analysis revealed that having a sex history outside of marriage with ≥1 sex partner and never using a condom with a spouse or casual partner were significant risk factors for HIV and HBV among drivers. Fortunately, we found that most of the drivers reported low alcohol and drug use. Concerning this study, the seroprevalence of HIV and HBV is highly associated with a history of having sex outside of marriage and sexual behavior among truck drivers and assistances. Additional studies are needed to further investigate other STIs and behavioral characteristics associated with factors in truck drivers/assistance in different truck stop regions in Sudan.

A GENERALIZATION OF THE TRANSMITTING BOUNDARY

The problem of wave propagation in a heterogeneous medimn, ineluding calculations of near-field seismograms and interacion of waves with man-made structures ornatural structures, etc, is an important problem in seismology and earthquake engineering. Interest in applying discrete methods to this problem has been greatly growing and a number of schemes of the treatment of the artificial boundaries of a finite computational rogion have been proposed over the last few years. By grouping and comparing most of the schemes, it is shown that if we seek a boundary condition suitable

Finite Element - Artificial Transmitting Boundary Method for Acoustical Field on Tapered Waveguide

In earlier approach, the 2-D acoustical field profiles on the substrate region are often calculated with BPM. In this paper, we present a new approach based on the finite element -artificial transmitting boundary method and calculate acoustical field on the substrate region.

Polarimetric scattering and transmitting of the Stokes vector from a layer of chiral small spheroids

To measure fully polarimetric scattering from random chiral small spheroids, the 2×2 dimensional (2×2-D) complex scattering amplitude matrix of randomly oriented, chiral small spheroid is derived. Polarimetric scattering from a bounded layer of non-uniformly oriented, chirally-active small spheroids in the Mueller matrix solution is obtained. Co-polarized and cross-polarized backscattering and polarization degree for any polarized incidence (χ, ψ) are numerically calculated. Transmitting of coherent Stokes parameters through the layer are also discussed. Either non-uniform orientation or chi-rality can yield non-diagonal extinction matrix ke and full eigenmatrix E due to the fact of forward depolarized-scattering functions <f°vh>, <f°hv> ≠ 0. Comparisons of fully polarimetric scattering from the chiral and achiral particulate media demonstrate the chirality effect on wave scattering and transmitting.

Analysis of maximal-ratio of transmitting/receiving antenna selection with perfect and partial channel information

To improve system performance and reduce the complexity and cost of receiver hardware,we investi-gated a new multiple-input multiple-output(MIMO)scheme combining maximal-ratio transmitting and receiver antenna selection(MRT/RAS).In this scheme,a single receiving antenna,which maximizes the signal-to-noise ratio(SNR)at the receiver,is selected for demodulation.The closed-form outage probability and the bit error rate(BER)of theMRT/RAS system are both presented.The simulation demonstrates that the MRT/RAS scheme can achieve a full diversity order as if all the receiving antennas were used.It is shown that the MRT/RAS scheme outperforms some more complex space-time codes of the same spectral efficiency.The ana-lytical results are verified by simulation.In the end,we also analyze the MRT/RAS system based on partial chan-nel information.

Dynamic characterization of tailing dam using fully coupled dynamic analysis with different boundary conditions-a case study

The seismic response analysis of a tailing dam is studied using a fully coupled effective stress approach in conjunction with an advanced multi yield surface plastic constitutive model for tailing material.Strain controlled static and cyclic triaxial tests were carried out to obtain the constitutive model for the tailing material.The tailing materials were collected from the Rampura Agucha tailing dam(Rajasthan State,India).A 2D nonlinear finite element(FE)model was then developed using different boundary conditions from the tailing embankment constructed using the downstream and upstream method of rising using OpenSees software.In first case,the model boundary was fixed in both the X and Y directions,and in the second case,viscous dashpots were introduced for both side and horizontal boundaries.The model was validated with experimental results on tailing material.Analyses were carried out considering five different earthquake motions,which were applied at the base.Comparisons of the different boundary conditions in terms of displacement flow vectors,pore pressure and stress-strain curves during shaking are presented.From the analysis,it was observed that the viscous boundary condition replicates the actual field conditions more accurately than the fixed boundary condition.In addition,it was found that the tailing embankment constructed by the downstream and upstream method of rising is not susceptible to liquefaction and lateral spreading for earthquake motions,even for a magnitude>5.5.