Optimization-based mode selection scheme for OAM millimeter wave system in the off-axis misalignment case

Millimeter-wave transmission combined with Orbital Angular Momentum(OAM)has the advantage of reducing the loss of beam power and increasing the system capacity.However,to fulfill this advantage,the antennas at the transmitter and receiver must be parallel and coaxial;otherwise,the accuracy of mode detection at the receiver can be seriously influenced.In this paper,we design an OAM millimeter-wave communication system for overcoming the above limitation.Specifically,the first contribution is that the power distribution between different OAM modes and the capacity of the system with different mode sets are analytically derived for performance analysis.The second contribution lies in that a novel mode selection scheme is proposed to reduce the total interference between different modes.Numerical results show that system performance is less affected by the offset when the mode set with smaller modes or larger intervals is selected.

Collision off-axis position dependence of relativistic nonlinear Thomson inverse scattering of an excited electron in a tightly focused circular polarized laser pulse

This paper presents a novel view of the impact of electron collision off-axis positions on the dynamic properties and relativistic nonlinear Thomson inverse scattering of excited electrons within tightly focused, circularly polarized laser pulses of varying intensities. We examine the effects of the transverse ponderomotive force, specifically how the deviation angle and speed of electron motion are affected by the initial off-axis position of the electron and the peak amplitude of the laser pulse. When the laser pulse intensity is low, an increase in the electron's initial off-axis distance results in reduced spatial radiation power, improved collimation, super-continuum phenomena generation, red-shifting of the spectrum's harmonic peak, and significant symmetry in the radiation radial direction. However, in contradiction to conventional understandings,when the laser pulse intensity is relatively high, the properties of the relativistic nonlinear Thomson inverse scattering of the electron deviate from the central axis, changing direction in opposition to the aforementioned effects. After reaching a peak, these properties then shift again, aligning with the previous direction. The complex interplay of these effects suggests a greater nuance and intricacy in the relationship between laser pulse intensity, electron position, and scattering properties than previously thought.

An improved algorithm based on equivalent sound velocity profile method at large incident angle

With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing method.The classical equivalent sound speed profile(ESSP)method replaces the measured sound velocity profile(SVP)with a simple constant gradient SVP,reducing the computational workload of beam positioning.However,in deep-sea environment,the depth measurement error of this method rapidly increases from the central beam to the edge beam.By analyzing the positioning error of the ESSP method at edge beam,it is discovered that the positioning error increases monotonically with the incident angle,and the relationship between them could be expressed by polynomial function.Therefore,an error correction algorithm based on polynomial fitting is obtained.The simulation experiment conducted on an inclined seafloor shows that the proposed algorithm exhibits comparable efficiency to the original ESSP method,while significantly improving bathymetry accuracy by nearly eight times in the edge beam.

Study on the optimal incident proton energy of ^(7)Li(p,n)^(7)Be neutron source for boron neutron capture therapy

Boron neutron capture therapy(BNCT)is recognized as a precise binary targeted radiotherapy technique that effectively eliminates tumors through the^(10)B(n,α)^(7)Li nuclear reaction.Among various neutron sources,accelerator-based sources have emerged as particularly promising for BNCT applications.The^(7)Li(p,n)^(7)Be reaction is highly regarded as a potential neutron source for BNCT,owing to its low threshold energy for the reaction,significant neutron yield,appropriate average neutron energy,and additional benefits.This study utilized Monte Carlo simulations to model the physical interactions within a lithium target subjected to proton bombardment,including neutron moderation by an MgF_(2)moderator and subsequent BNCT dose analysis using a Snyder head phantom.The study focused on calculating the yields of epithermal neutrons for various incident proton energies,finding an optimal energy at 2.7 MeV.Furthermore,the Snyder head phantom was employed in dose simulations to validate the effectiveness of this specific incident energy when utilizing a^(7)Li(p,n)^(7)Be neutron source for BNCT purposes.

Training for Vessel Collision Prevention:Circumstances and Causes of Near-Miss Incidents

Among the near-miss incidents related to the operation of training ship of the JMETS(Japan Agency of Maritime Education and Training for Seafarers),three characteristic cases were analyzed,extracting their circumstances and near-miss factors.Based on the results of these analyses,measures to prevent vessel collisions were studied,from which we proposed collision prevention training.The training entails(1)lookout training,(2)navigation planning training,(3)resource management training,and(4)false assumption prevention training.In future research,we aim to verify the effectiveness of the proposed training,improve the training’s effectiveness,and contribute to the development of effective anti-collision support devices.

GNSS array receiver faced with overloaded interferences:anti-jamming performance and the incident directions of interferences

Anti-jamming solutions based on antenna arrays enhance the anti-jamming ability and the robustness of global navigation satellite system(GNSS)receiver remarkably.However,the performance of the receiver will deteriorate significantly in the overloaded interferences scenario.We define the overloaded interferences scenario as where the number of interferences is more than or equal to the number of antenna arrays elements.In this paper,the effect mechanism of interferences with different incident directions is found by studying the anti-jamming performance of the adaptive space filter.The theoretical analysis and conclusions,which are first validated through numerical examples,reveal the relationships between the optimal weight vector and the eigenvectors of the input signal autocorrelation matrix,the relationships between the interference cancellation ratio(ICR),the signal to interference and noise power ratio(SINR)of the adaptive space filter output and the number of interferences,the eigenvalues of the input signal autocorrelation matrix.In addition,two simulation experiments are utilized to further corroborate the theoretical findings through soft anti-jamming receiver.The simulation results match well with the theoretical analysis results,thus validating the effect mechanism of overloaded interferences.The simulation results show that,for a four elements circular array,the performance difference is up to 19 dB with different incident directions of interferences.Anti-jamming performance evaluation and jamming deployment optimization can obtain more accurate and efficient results by using the conclusions.

Unmanned aerial vehicle based intelligent triage system in mass-casualty incidents using 5G and artificial intelligence

BACKGROUND:Rapid on-site triage is critical after mass-casualty incidents(MCIs)and other mass injury events.Unmanned aerial vehicles(UAVs)have been used in MCIs to search and rescue wounded individuals,but they mainly depend on the UAV operator’s experience.We used UAVs and artificial intelligence(AI)to provide a new technique for the triage of MCIs and more efficient solutions for emergency rescue.METHODS:This was a preliminary experimental study.We developed an intelligent triage system based on two AI algorithms,namely OpenPose and YOLO.Volunteers were recruited to simulate the MCI scene and triage,combined with UAV and Fifth Generation(5G)Mobile Communication Technology real-time transmission technique,to achieve triage in the simulated MCI scene.RESULTS:Seven postures were designed and recognized to achieve brief but meaningful triage in MCIs.Eight volunteers participated in the MCI simulation scenario.The results of simulation scenarios showed that the proposed method was feasible in tasks of triage for MCIs.CONCLUSION:The proposed technique may provide an alternative technique for the triage of MCIs and is an innovative method in emergency rescue.

Traffic Incident Management Performance Measures: Ranking Agencies on Roadway Clearance Time

This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requiring more training or resources for incident management. Previous NCHRP reports discussed usage of different factors including incident severity, roadway characteristics, number of lanes involved and time of incident separately for estimating the performance. However, it does not tell us how to incorporate all the factors at the same time. Thus, this study aims to account for multiple factors to ensure fair comparisons. This study used 149,174 crashes from Iowa that occurred from 2018 to 2021. A Tobit regression model was used to find the effect of different variables on roadway clearance time. Variables that cannot be controlled directly by agencies such as crash severity, roadway type, weather conditions, lighting conditions, etc., were included in the analysis as it helps to reduce bias in the ranking procedure. Then clearance time of each crash is normalized into a base condition using the regression coefficients. The normalization makes the process more efficient as the effect of uncontrollable factors has already been mitigated. Finally, the agencies were ranked by their average normalized roadway clearance time. This ranking process allows agencies to track their performance of previous crashes, can be used in identifying low performing agencies that could use additional resources and training, and can be used to identify high performing agencies to recognize for their efforts and performance.

Far-field vector-diffraction of off-axis parabolic mirror under oblique incidence

Based on a full vector-diffraction theory, a detailed theoretical study is carried out, aiming at providing a clear insight into the effects of different focusing and off-axis parabola parameters on far-field vector-diffraction properties of an offaxis parabolic mirror in the presence of misalignments of the incoming beam. The physical origin of these effects is also explored. The results show that the far-field intensity profile is altered by the distortion-, coma-, and astigmatism-like aberrations, which are caused by oblique incidence rather than inherent aberrations for the off-axis configuration. The radius of 90% encircled energy also increases but does not change monotonically with incident beam size increasing, or rather,it first decreases and then increases. The focal shift strongly depends on the effective focal length and oblique incidence angle, but it is almost independent of the beam size, which affects the focusing spot patterns. The intensity distribution produces a higher astigmatic image with off-axis angle increasing. Coma-like aberration starts to become dominant with beam size increasing and results in larger curved propagation trajectory. The incident polarization also affects the intensity distribution. The variation in the Strehl ratio with oblique incidence angle strongly depends on the misalignment direction and beam size as well. In addition, we find that the difference in locus between the catacaustic and the diffraction focus in the meridian is small. But the locus of the sagittal foci is obviously different from the locus of the meridian foci and the catacaustic focus. Moreover, the peak intensity of the sagittal focus is maximum, and the ratio of the peak intensity to that in the meridian plane is approximately 1.5. Understanding these effects is valuable for assessing a practical focused intensity and describing the motion of charged particles under a strong electric field in ultraintense laser–matter interaction.

Cancer incidence and mortality in China,2022

Background:The National Cancer Center(NCC)of China regularly reports the nationwide statistics on cancer incidence and mortality in China.The International Agency for Research on Cancer(IARC)calculates and publishes the cancer burden of countries around the world every two years.To ensure consistency between the actual surveillance data in China and the data published by IARC,NCC has received approval from the National Health Commission and IARC to simultaneously release the cancer burden data for China in GLOBOCAN 2022.Methods:There were a total of 700 registries reporting high-quality data on cancer incidence and mortality across China in 2018,of which 106 registries with continuous monitoring from 2010 to 2018 were used to establish an age-period-cohort model to simulate the trend of cancer incidence and mortality and to estimate the incidence and mortality in China in 2022.In addition,we analyzed the temporal trends of age-standardized cancer incidence and mortality from 2000 to 2018 using data from 22 continuous cancer registries.Results:It was estimated about 4,824,700 new cancer cases and 2,574,200 new cancer deaths occurred in China in 2022.Cancers of the lung,colon-rectum,thyroid,liver and stomach were the top five cancer types,accounting for 57.42%of new cancer cases.Cancers of the lung,liver,stomach,colon-rectum and esophagus were the five leading causes of cancer deaths,accounting for 67.50%of total cancer deaths.The crude rate and age-standardized incidence rate(ASIR)were 341.75 per 100,000 and 201.61 per 100,000,respectively.The crude mortality rate was 182.34 per 100,000 and the age-standardized mortality rate(ASMR)was 96.47 per 100,000.The ASIR of all cancers combined increased by approximately 1.4%per year during 2000–2018,while the ASMR decreased by approximately 1.3%per year.We observed decreasing trends in ASIR and ASMR for cancers of the esophagus,stomach,and liver,whereas the ASIR increased significantly for cancers of the thyroid,prostate,and cervix.Conclusions:Cancer remains a major public health concern in China,with a cancer profile that reflects the coexistence of developed and developing regions.Sustained implementation of prevention and control measures has resulted in significant reductions in the incidence and mortality rates of certain historically high incidence cancers,such as esophageal,stomach and liver cancers.Adherence to the guidelines of the Healthy China Action Plan and the Cancer Prevention and Control Action Plan,along with continued efforts in comprehensive risk factor control,cancer screening,early diagnosis and treatment,and standardization of diagnostic and therapeutic protocols,are key strategies to effectively mitigate the increasing cancer burden by 2030.

Simultaneous detection of CH_(4)and CO_(2)through dual modulation off-axis integrated cavity output spectroscopy

This study established a novel method for the simultaneous detection of two-component gases.Radio frequency(RF)white noise disturbance laser current and wavelength modulation were simultaneously used to improve the off-axis integrated cavity output spectroscopy technique,and a high-precision dual modulation OA-ICOS(RF-WM-OA-ICOS)system was established.The two laser beams were coupled into one laser beam that was applied incident to the cavity of RF-WM-OA-ICOS system.The second harmonic signals of CH_(4)and CO_(2)gas simultaneously appeared in the rising or falling edge of a triangular wave.This method was used to measure CH_(4)and CO_(2)with different concentrations.The results indicated that the proposed system has high stability and can accurately and simultaneously measure the concentrations of CH_(4)and CO_(2),with an optimal integration time of 220 s.The minimum detection limit was 10 ppb for CH_(4)and 1.5 ppm for CO_(2).The corresponding noise equivalent absorption sensitivity values were calculated as 2.67×10^(-13)cm^(-1)·Hz^(-1/2)and 5.18×10^(-11)cm^(-1)·Hz^(-1/2),respectively.The proposed dual-component gas simultaneous detection method can also be used for high-precision simultaneous detection of other gases.Therefore,this study may serve as a reference for developing portable multicomponent gas analyzers.

Methodology for Automatically Setting Camera View to Mile Marker for Traffic Incident Management

Traffic incident management (TIM) is a FHWA Every Day Counts initiative with the objective of reducing secondary crashes, improving travel reliability, and ensuring safety of responders. Agency roadside cameras play a critical role in TIM by helping dispatchers quickly identify the precise location of incidents when receiving reports from motorists with varying levels of spatial accuracy. Reconciling position reports that are often mile marker based, with cameras that operate in a Pan-Tilt-Zoom coordinate system relies on dispatchers having detailed knowledge for hundreds of cameras and perhaps some presets. During real-time incident dispatching, reducing the time it takes to identify the most relevant cameras and setting their view on the incident is an important opportunity to improve incident management dispatch times. This research develops a camera-to-mile marker mapping technique that automatically sets the camera view to a specified mile marker within the field-of-view of the camera. Over 350 traffic cameras along Indiana’s 2250 directional miles of interstate were mapped to approximately 5000 discrete locations that correspond to approximately 780 directional miles (~35% of interstate) of camera coverage. This newly developed technique will allow operators to quickly identify the nearest camera and set them to the reported location. This research also identifies segments on the interstate system with limited or no camera coverage for decision makers to prioritize future capital investments. This paper concludes with brief discussion on future research to automate the mapping using LiDAR data and to set the cameras after automatically detecting the events using connected vehicle trajectory data.

Teaching Intercultural Competence Using Critical Incident and Cultural Story Telling

Intercultural literacy is attached increasingly great importance in this interconnected world.People from diversified cultural backgrounds need to interact with each other for various purposes.Schools and organizations offer courses to improve people’s intercultural competence.This paper examines two effective techniques to teach intercultural competence in the classroom setting:critical incident activity and cultural story telling.These two strategies can help achieve the desired objectives of Michael Byram’s intercultural communication model.

Characteristic Analysis of Off-Axis Meta-Lens

Meta-lens are a new type of planar optical element that can flexibly manipulate the phase, polarization and amplitude of the beam, and are currently receiving a great deal of attention as they are easier to process and manufacture. Off-axis meta-lens are a special type of meta-lens with a certain degree of dispersion that can be used as a beam-splitting element, providing a unique and feasible way to realize micro-miniature instruments. We analyze the effects of different numerical apertures and off-axis angles on the spectral resolution, focusing efficiency and simulation results of off-axis meta-lens to provide ideas for subsequent research and application of off-axis meta-lens. A number of off-axis meta-lens with parameters NA = 0.408 α = 13°, NA = 0.18 α = 13° and NA = 0.408 α = 20° were simulated through Lumerical software. The results show that the off-axis angle is related to the resolution;the larger the angle, the better the spectral resolution but the lower the focusing efficiency;when the numerical aperture is smaller, the smaller the coverage of the phase distribution, which will lead to a larger deviation between simulation and theory. The designer needs to balance the numerical aperture, off-axis angle and other parameters reasonably according to the requirements in order to achieve the desired effect. The findings of this study have important reference values for the theoretical analysis of off-axis meta-lens and the design of parameters in practical applications. .

Influence of Temperature and Humidity on the Incidence of Pulmonary Tuberculosis in Hainan,China,2004-2018

According to the World Health Organization’s Global Tuberculosis Report 2023,there were 10.6 million cases of tuberculosis(TB)worldwide in 2022,an increase of 2.8%over 2021,and 1.3 million people had already died of the disease.The report also indicated that approximately 748,000 new cases occurred in China in 2022,accounting for 7.1%of the global total,with an incidence of 52/100,000.

Temporal trends and cohort variations of gender-specific major depressive disorders incidence in China:analysis based on the age-period-cohortinteraction model

Background Major depressive disorders(MDDs)impose substantial burdens on individuals and society;however,further detailed analysis is still needed for its long-term trends.Aims This study aimed to analyse the gender-specific temporal trends and cohort variations of MDD incidence among Chinese residents over the past three decades.Methods Employing the age-period-cohort-interaction model and leveraging data from the Global Burden of Disease Study 2019,this research identified and analysed incidence trends of MDD among Chinese males and females aged 5-94 years from 1990 to 2019 across three dimensions,encompassing age,period and birth cohort.Results The analysis reveals age-related effects,indicating heightened MDD risk among adolescents and older adults.Specifically,individuals entering the older adulthood at the age of 65-69 significantly increased the risk of MDD by 64.9%.People aged 90-94 years witnesseda 105.4%increase in MDD risk for the overall population,with females and males in this age group experiencing a 75.1%and 103.4%increase,respectively.In terms of period effects,the risk of MDD displayed a decline from 1990 to 1994,followed by a rebound in 2008.Cohort effects demonstrated diverse generational patterns,with generationⅠand generationⅢmanifesting opposing‘age-as-level'trends.GenerationⅡand generationⅣexhibited'cumulative disadvantage'and'cumulative advantage'patterns,respectively.Age effects indicated an overall higher risk of MDD incidence in females,while cohort effects showed greater variations of MDD incidence among females.Conclusions The study underscores the substantial effects of age,period and cohort on MDD across genders in China.Priority interventions targeting vulnerable populations,including children,adolescents,older adults,females and the post-millennium birth cohort,are crucial to mitigate the impact of MDD.

Knee Arthroplasty Incidence Rate vs. Revision of Knee Arthroplasty and Its Associated Comorbidities in Colombia

Introduction: Total knee arthroplasty (TKA) has been established as a transformative solution in the treatment of advanced degenerative diseases of the knee, such as osteoarthritis, rheumatoid arthritis, and posttraumatic arthritis. In this sense, TKA surgery, which seeks to replace the damaged joint with prosthetic components, has proven to be highly effective in relieving pain, improving joint function, and, ultimately, significantly increasing patients’ quality of life. The present study describes the TKA and revision knee arthroplasty (RKA) rates and, identifies the associated co morbidities in the Colombian context. Methods: A retrospective cohort study was carried out. It describes demographic and clinical characteristics between two groups of patients, TKA or RKA, and its association with mortality at 30 days, 90 days, or one year after the intervention. Results: The incidence rate of the population undergoing TKA was approximately 11.71 cases per 100,000 inhabitants. Furthermore, the incidence rate for revision knee arthroplasty (RKA) procedures in the same period was around 0.96 per 100,000 inhabitants. In both groups at 30 days postoperatively, a total mortality rate of 0.09%was recorded. When the follow-up was extended to 90 days, it increased to 0.15%;at one year postoperatively, it rose to 0.88%. Conclusion: Mortality after surgery was low in Colombia in 2019. Although RKA is a beneficial procedure, in certain circumstances, it was noted that it carries a higher risk compared to primary TKA. Our results emphasize the importance of careful evaluation of co morbidities and risk factors in patients undergoing these surgical procedures. The application of quality-of-life questionnaires should be considered in future studies on effectiveness and mortality for TKA and RKA in our country.

Incidence and Management of Early Postoperative Hypoxemia after Abdominal Surgery at Teaching Hospital

Background: Oxygen saturation refers to the quantity of oxygenated hemoglobin in the blood, that is to say the level of oxygen measurable in the red blood cells when they have passed through the lungs. The aim of this study was to describe the management of early postoperative hypoxemia after abdominal surgery at the Yaounde General Hospital (YGH). Method: This is a quantitative, observational study, with a descriptive aim, which took place in the anesthesiology department of the YGH, over a period of 2 months from August 1st to October 1st, 2023. The study included all the patients ≥18 years, of both sexes who had abdominal surgery under general anesthesia and were willing to participate during the time of data collection. The variables studied were the sociodemographic and clinical characteristics, risk factors for oxygen desaturation, postoperative variations in SPO2 and therapeutic tools. Results: We collected 30 patients among whom 11 presented with early postoperative hypoxemia i.e. a frequency of 36.7%. The age of the patients ranged from 18 to 63 years and the mean was 42.47 ± 13.5 years on average. The sex ratio was 0.5. Hysterectomy was the most commonly performed surgery (23.3%). The most common comorbidity was high blood pressure (30%). Half of the patients had midline incision. Supra-umbilical surgery predominated (56.7%), intraoperative blood loss ≥500 ml in 46.7% of cases. Upper abdominal surgery with, subcostal incision and blood loss ≥500 ml are statistically significant risk factors for the occurrence of early postoperative hypoxemia (P Conclusion: Hypoxemia is the result of impaired respiratory function favored by the conditions encountered during the early postoperative period.

A nonlocal dispersal and time delayed HIV infection model with general incidences

Biologically,because of the impact of reproduction period and nonlocal dispersal of HIV-infected cells,time delay and spatial heterogeneity should be considered.In this paper,we establish an HIV infection model with nonlocal dispersal and infection age.Moreover,applying the theory of Fourier transformation and von Foerster rule,we transform the model to an integrodifferential equation with nonlocal time delay and dispersal.The well-posedness,positivity,and boundedness of the solution for the model are studied.

Incidence and Survivability of Acute Lymphocytic Leukemia Patients in the United States: Analysis of SEER Data Set from 2000-2019

The main goal of this research is to assess the impact of race, age at diagnosis, sex, and phenotype on the incidence and survivability of acute lymphocytic leukemia (ALL) among patients in the United States. By taking these factors into account, the study aims to explore how existing cancer registry data can aid in the early detection and effective treatment of ALL in patients. Our hypothesis was that statistically significant correlations exist between race, age at which patients were diagnosed, sex, and phenotype of the ALL patients, and their rate of incidence and survivability data were evaluated using SEER*Stat statistical software from National Cancer Institute. Analysis of the incidence data revealed that a higher prevalence of ALL was among the Caucasian population. The majority of ALL cases (59%) occurred in patients aged between 0 to 19 years at the time of diagnosis, and 56% of the affected individuals were male. The B-cell phenotype was predominantly associated with ALL cases (73%). When analyzing survivability data, it was observed that the 5-year survival rates slightly exceeded the 10-year survival rates for the respective demographics. Survivability rates of African Americans patients were the lowest compared to Caucasian, Asian, Pacific Islanders, Alaskan Native, Native Americans and others. Survivability rates progressively decreased for older patients. Moreover, this study investigated the typical treatment methods applied to ALL patients, mainly comprising chemotherapy, with occasional supplementation of radiation therapy as required. The study demonstrated the considerable efficacy of chemotherapy in enhancing patients’ chances of survival, while those who remained untreated faced a less favorable prognosis from the disease. Although a significant amount of data and information exists, this study can help doctors in the future by diagnosing patients with certain characteristics. It will further assist the health care professionals in screening potential patients and early detection of cases. This could also save the lives of elderly patients who have a higher mortality rate from this disease.