Dual loop feedback pre-distortion in satellite communication

Since the satellite communication goes in the trend of high-frequency and fast speed, the coefficients updating and the precision of the traditional pre-distortion feedback methods need to be further improved. On this basis, this paper proposes dual loop feedback pre-distortion, which uses two first-order Volterra filter models to reduce the computing complexity and a dynamic error adjustment model to construct a revised feedback to ensure a better pre-distortion performance. The computation complexity, iterative convergence speed and precision of the proposed method are theoretically analyzed. Simulation results show that this dual loop feedback pre-distortion can speed the updating of coefficients and ensure the linearity of the amplifier output.

Visual Communication Design of Digital Media in Digital Advertising

With the continuous development of modem science and technology,great changes have taken place in the advertising media industry where the traditional form of advertising has gradually changed into digital ones.Compared with the traditional advertising,digital advertising has more flexibility and has a variety of forms in its advertising creation according to product itself.In addition,visual communication design plays a critical role where it is an important way to improve digital advertising.Therefore,it is necessary to optimize visual communication design in order to improve the quality of digital advertising.In this way,this article carries out an in-depth research and analysis on the visual communication design of digital media in digital advertising and put forward some reasonable suggestions and measures,aiming to further promote the development of China's advertising media industry.

Dual Band Switched Beam Textile Antenna for 5G Wireless Communications

This paper presents the single element dual band switched beam textile antenna.The antenna can operate at frequencies of 0.7 and 2.6 GHz using for 5G wireless communication applications.Textile fabric is considered to be used for substrate layer at the parts of a microstrip antenna for wireless body area network.The beam pattern of antenna can be switched into two directions by changing the position of shorted-circuit points at each edge of antenna.The main beam direction is 45°/225°when corner A is shorted while it steers at 135°/315°when corner B is shorted circuit.The advantage of the proposed antenna is the decrease of the problems like interference,light weight,flexibility and ability to switch beam easily.In addition,the results of the fabricated antenna are compared with the simulated ones.Moreover,the antenna is bent with curvature radius of 6 mm in forward direction.The effects of the bent antenna are studied.The results can confirm that radiation patterns of the bending antenna can be pointed into two directions when changing the positions of shorted circuit.Therefore,the proposed antenna can switch beam patterns,it is flexible,and it can operate at dual-band frequency on textile.

DUAL MODE WIDEBAND BAND-PASS FILTER WITH NOTCHED BAND FOR COMMUNICATION SYSTEM

This paper presents a planar microstrip wideband dual mode Band-Pass Filter(BPF) from 2 GHz to 3.4 GHz with a notched band at 2.62 GHz.The dual mode band-pass filter consists of a ring resonator with two quarter-wavelength open-circuited stubs at =90o and =0o,respectively.A square perturbation stub has been put at the corner of the ring resonator to increase the narrow stopbands and improve the performance of selectivity.By using a parallel-coupled feed line,a narrow notched band is introduced at the required frequency and its Fractional BandWidth(FBW) is about 5%.The proposed filter has a narrow notched band and a wide pass-band with a sharp cutoff frequency characteristic,the attenuation rate for the sharp cutoff frequency responses is 297.17 dB/GHz(cal-culated from 1.959 GHz with-34.43 dB to 2.065 GHz with-2.93 dB) and 228.10 dB/GHz(calculated from 3.395 GHz with-2.873 dB to 3.507 GHz with-28.42 dB).This filter has the advantages of good insertion loss in both operating bands and two rejections of greater than 16 dB in the range of 1.59 GHz to 1.99 GHz and 3.49 GHz to 3.98 GHz.Having been presented in this article,the measurement results agree well with the simulation results,which validates our idea.

DVCast:denoising and variable dct for analog visual communications

Recently,analog visual transmission has attracted considerable attention owing to its graceful performance degradation for various wireless channels.In this study,we propose a novel analog visual communications system,named DVCast,in which an image denoising algorithm is used to fully utilize spatial correlation;moreover,the variable block size Discrete Cosine Transform(DCT)is used to preserve more correlation information in an image.Obviously,there is a tradeoff between system performance and computing complexity.Therefore,to improve the real-time performance of the proposed system,implementation of Block Matching with 3D filtering(BM3D)and DCT by Graphics Processing Units(GPUs)is introduced.According to DCT block size,i.e.,88,1616,and 3232,the schemes DVCast8,DVCast16,and DVCast32,respectively,are designed and implemented.Simulations show that DVCast with larger block size achieves better gain and visual quality than reference schemes.Moreover,it requires less computing time.DVCast32 outperforms conventional digital schemes by approximately 3.51 dB and achieves a 1.12 dB gain over state-of-the-art reference schemes.Furthermore,the analysis shows that DVCast can reduce overhead by at least 75%.

Visual Communication Design of Intangible Cultural Heritage Based on Internet+

Wuchuan Piaose Art is a traditional folk cultural activity of the Han nationality in Wuchuan City,Guangdong Province.It is a comprehensive plastic art integrating drama,music,art,magic,acrobatics,and mechanics.Exploring and recording the intangible cultural heritage of Wuchuan in an Internet+and computer-aided way is of great significance to the practice and historical research of Wuchuan.It provides a folklore material for the artistic creation of figure paintings,which is of pioneering significance.

The Comprehensive and Integrating Design of Subway Visual Communication and Urban Culture

The subway has become an dominant form for public transportation in all the great metropolis. It not only saves energy and time ,but also relieves stress caused by the dense commuting. As a high-effi cient travel mode in modern city, the metro can not only relieve the ground traffi c pressure, but also represents the culture and value of the city, which is the essence of our life. Metro visual communication design of developed countries in the world is almost closely related to the origin of urban culture, then the metro culture with local specialties has been formed. Therefore, comparative research on the situation of metro visual communication design both can induce the integration and regeneration of urban metro visual communication design and urban culture of China, as well as the formation and development of the metro culture.

Exploring the Practice of Cultivating Design Thinking Skills in Visual Communication Major

The development of diversified industries has promoted the emergence of diversified majors,and visual communication is a new type of profession,and the course is also a new type of course,which requires students to have better design thinking,and how to improve the design thinking of visual communication majors through daily learning.Based on this,this paper proposes a definition of visual communication and the relevance of design thinking.It proposes a strategy to enhance the design thinking ability of visual communication majors.

Visual Communication Design in Food Commercial Photography

Photography is a new visual aesthetic field,which is created by multifarious visual communication elements.In the context of the continuous development of science and technology,based on people’s pursuit of beauty,the increasingly portability of the photographic equipment has become more and more independent,so photography has been integrated into all aspects of life.Food commercial photography emerges in this case,which is not only widely used in commercial areas including catering,but also has become an art of publicity using the characteristics of photography.In this paper,the food commercial photography is analyzed and studied from the application of light and colour,and the corresponding suggestions are given.

Unified Smith Predictor Based H_∞ Wide-Area Damping Controller to Improve the Control Resiliency to Communication Failure

Inter-area low frequency oscillation in power system is one of the major problems for bulk power transmission through weak tie lines.Use of wide-area signal is more effective than the local area signal in damping out the inter-area oscillations.Wide area measurement system(WAMS)is convenient to transmit the wide area signal through the communication channel to the remote location.Communication failure is one of the disastrous phenomena in a communication channel.In this paper,a dual input single output(DISO)Hm controller is designed to build the control resiliency by employing two highest observability ranking wide area signals with respect to the critical damping inter-area mode.The proposed controller can provide sufficient damping to the system and also the system remains stabilized if one of the wide-area signals is lost.The time delay is an unwanted phenomenon that degrades the performance of the controllers.The unified Smith predictor approach is used to design a Hm controller to handle the time delay.Kundur's two-area and IEEE-39 bus test systems are considered to verify the effectiveness of the proposed controller.From the simulation results,it is verified that,the proposed controller provides excellent damping performance at normal communication and improves the controller resiliency to counteract the communication failure.

Collision Classification MAC Protocol for Underwater Acoustic Communication Networks Using Directional Antennas

Traditional underwater acoustic communication networks(UACNs)generally use omnidirectional transmission technology that causes a large number of data-packet collisions,thus resulting in low network throughput and high end-to-end delays.Compared with omnidirectional transmission technology,directional technology only sends and receives data packets in a specified direction.This can significantly reduce the probability of collisions and improve network performance.However,it also causes a deafness problem,which occurs when the sending node sends a data packet to the receiving node but the receiving node is unable to reply to the sender,because its antenna beam is closed.To resolve this issue,this study proposes a collision classification media access control(CC-MAC)protocol for UACNs.With this protocol,the underwater acoustic channel is divided into two subchannels,and the nodes transmit corresponding data types on them.The sending node can estimate the current status of the receiving node(i.e.,no collision,normal collision,deafness)according to the type of the data packet received and the sub-channel it arrived on,and it can choose correct options to improve network efficiency.Finally,we verify the performance of CC-MAC via simulations,showing that the protocol achieved higher network throughput and lower end-toend delays.

Wearable Antenna for Power Efficient On-Body and Off-Body Communications

A novel dual-band and diverse radiation pattern antenna is proposed for power efficient on-body and off-body communications intended for various applications in healthcare and sport monitoring. The antenna is dual band at 2.45 GHz (ISM band) with omnidirectional radiation pattern over the body surface to communicate power efficiently with other co-located body worn devices and at 1.9 GHz (PCS band), it has directive radiation pattern towards off the body to communicate from on-body device to off-body devices. The free space and on-body performances of the antenna are investigated by both simulation and experiment. The antenna shows very good on-body radiation efficiency of 58% at 2.45 GHz and 61% at 1.9 GHz. Good on-body gain is noticed at both frequency bands. Results show that the gain of the proposed antenna increases by 4.7% at 2.45 GHz and 3.2% at 1.9 GHz when placed on the body.

Effects of Communication Robot on Distress Reduction in Mammography

Mammography is obviously useful for the early detection and diagnosis of breast diseases in women. However, it usually involves anxieties and pains. This paper aimed to explore effects of the communication robot on distress reduction in mammography. Nineteen healthy women participated in the examination. They were randomly assigned to either an experimental group (n = 9) or a control group (n = 10). The participants in the experimental group talked and played with a communication robot before mammography. PALRO (FUJISOFT Inc., Tokyo, Japan) was used as the communication robot, which was a chatty, comforting robot. PALRO can communicate with the human and has several specific applications such as dancing, singing and talking about knowledge of various things. Autonomic nervous activities were observed before and during mammography. Degrees of subjective pain associated with mammography were also assessed using a visual analogue scale (VAS). As a result, autonomic nervous activities between the experimental group and the control group were not significantly different. Unfortunately, the communication robot did not help to intensify parasympathetic nerve activities, which became dominant at rest or a relaxed state. On the other hand, the VAS scores for pain in the experimental group were significantly smaller than ones in the control group (p < 0.01). This result suggested that the communication robot was useful for relieving degrees of subjective pain associated with mammography. In conclusion, communication with a robot before mammography would yield positive emotions and it would be related to the pain alleviation during mammography.

Model of Verbal Communication with Blind Patient:Application in Nursing Appointment

It was aimed at validating the applicability of the Model of Verbal Communication with blind people in nursing appointment in the stages of the nursing process. A methodology of quantitative study was used with 30 nurses and 30 blind people who participated in the study, divided in control and experimental groups. 30 nursing appointments took place;they were recorded and analyzed by three judges. The experimental group had excellent performance in following protocol (95.6%);taking notes informing the reason for silence (93.4%);and avoiding long silence (100%). In interventions, it presented excellence in all the items, in the evaluation stage, there were no bad/terrible actions. In none of the actions the control group presented better performance than the experimental one. The use of the Model is recommended in nursing appointment with blind patient.

Deep Neural Network-based Speaker-Aware Information Logging for Augmentative and Alternative Communication

People with complex communication needs can use a high-technology augmentative and alternative communication device to communicate with others.Currently,researchers and clinicians often use data logging from high-tech augmentative and alternative communication devices to analyze augmentative and alternative communication user performance.However,existing automated data logging systems cannot differentiate the authorship of the data log when more than one user accesses the device.This issue reduces the validity of the data logs and increases the difficulties of performance analysis.Therefore,this paper presents a solution using a deep neural network-based visual analysis approach to process videos to detect different augmentative and alternative communication users in practice sessions.This approach has significant potential to improve the validity of data logs and ultimately to enhance augmentative and alternative communication outcome measures.

基于MaxViT和改进几何特征点法的车载单目视觉测速方法研究

车载视觉测速技术作为自动驾驶车辆组合测速技术的重要组成,具有硬件成本低、算法拓展性强、低速下测量准确等特点,应用前景广阔。为进一步提高视觉测速算法在各类工况下的精度和鲁棒性,将几何特征点法在特征点充足时测速精度高和深度学习方法在多场景下测速稳定的优势进行结合,提出一种基于MaxViT和改进几何特征点法的车载单目视觉测速算法。该算法构建基于双输入MaxViT网络和改进几何特征点法的双通道,并行处理车载前视相机获取的连续3帧输入图像序列,滚动估计车辆当前速度,其中双输入MaxViT网络差异化提取图像不同区域的光流特征,估计当前速度所在的置信度为90%的速度区间,改进特征点法基于特征点运动计算当前速度估计值。当速度估计值落在双输入MaxViT网络估计的速度区间时,以该估计值作为实时车速测量值,否则以速度区间中值作为实时车速测量值。当算法迭代运行多帧后,将速度区间中值作为本帧速度输出以减小累积误差。使用6个车速小于40 km/h且包括加减速等工况与直弯道等场景的自建数据集进行实验验证,以理论测速精度0.1 m/s的GPS速度信号为参考速度,本文方法平均相对测速误差少于1.37%,最大相对测速误差少于6.13%。实验结果表明,提出的新方法有效提高了车载视觉测速精度与鲁棒性,可为多元车载视觉测速方法融合提供理论支撑。

正十六烷引燃甲烷预混合气可视化实验研究

为探究环境温度、甲烷预混时间以及引燃燃料喷射压力对正十六烷引燃甲烷预混合气着火及火焰传播特性的影响,本文利用高速摄影技术及阴影拍摄方法,基于定容光学测试系统进行了可视化实验。研究结果表明:提高环境温度,引燃燃料滞燃期缩短,火焰发展速率增加并出现主燃区外预混合气局部着火;预混时间较短时,燃烧产生的碳烟较多,火焰发展速率随混合时间的增加而减小,当预混时间较长时,火焰发展速率趋于稳定;提高引燃燃料喷射压力,引燃燃料喷雾贯穿距离增大,滞燃期缩短,起始着火点位置发生变化,火焰发展速率增加。

双源双能量CT视觉评估和定量分析对椎体骨髓水肿的诊断价值

目的:探讨双源双能量CT(DECT)虚拟去钙(VNCa)技术中视觉评估(VE)和定量分析对椎体骨髓水肿(BME)的诊断价值。方法:回顾性分析2020年8月至2022年4月60例胸腰椎新鲜骨折(观察组)及60例陈旧性骨折(对照组)患者的临床及影像资料。以MRI结果为参考,将DECT的VE结果与之对比,分析1.75和1.45斜率对BME的诊断效能;比较新鲜与陈旧性骨折的定量参数(vCT、rCT、CaD、FF、ΔvCT)差异并绘制ROC曲线,采用Z检验比较曲线下面积(AUC)差异;进一步评估VE与定量参数联合的诊断效能。结果:1.75与1.45斜率VE诊断新鲜与陈旧性骨折的敏感度分别为88.0%、69.3%,特异度分别为93.8%、87.5%,1.75斜率的诊断符合率为90.3%,高于1.45斜率的78.7%,差异有统计学意义(χ^(2)=7.987,P<0.05)。椎体新鲜与陈旧性骨折的vCT、rCT、FF、ΔvCT值差异均有统计学意义(P均<0.05),其中ΔvCT值的AUC值最高(0.96),诊断阈值为28.5 HU时,敏感度、特异度分别为89.3%、96.2%,与其他定量参数差异均有统计学意义(P均<0.05)。VE的Youden指数(0.82)高于vCT(0.62)而略低于ΔvCT(0.86);VE与定量参数联合的AUC值(0.95)低于ΔvCT。结论:VNCa技术VE和定量分析对椎体骨髓水肿均具有较高的诊断效能,两者联合的诊断价值不高。

基于双循环Transformer的三维人体姿态估计

针对视觉传感器采集到的图像进行三维人体姿态估计,提出一种双循环Transformer网络模型,有效地从二维关键关节点中提取时空维度高相关性特征,增大感受野,从而提高三维姿态估计的精度。通过在视觉传感器采集得到的公开数据集Human3.6M上的仿真实验,验证了双循环Transformer算法的性能。分析结果表明,最终估计得到的三维人体关节点的平均关节点位置偏差MPJPE(Mean Per Joint Position Error)为41.6 mm,相比于现有方法有一定提升,可以应用到许多下游相关工作中,有着较强的应用价值。