Comparison study of harmonic imaging （HI） and fundamental imaging （FI） in fetal echocardiography

Objectives: To directly compare the quality of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography and to determine any differences in image quality between the two modalities. Methods: Fetal echocardiograms were performed with the use of FI and HI in 58 fetuses, image quality and visualization of left and right atria, left and right ventricles, mitral and tricuspid valves, aortic and pulmonary valves, left and right ventricular outflow tracts were evaluated and compared between FI and HI. Results: Mean HI scores were higher than mean FI scores (2.73±0.43 vs 2.16±0.69, P <0.001)for all the cardiovascular structures evaluated. Compared with FI, HI improved the image quality and visualization of fetal cardiac structures in subjects with both good (2.73±0.43 vs 2.88±0.32, P <0.001) and suboptimal (1.65±0.41 vs 2.58±0.47, P <0.001) echocardiographic windows. The interobserver correlation coefficient for the grading scores was 0.74 ( P <0.001). Conclusions: harmonic imaging enhances and improves the image quality of fetal echocardiography; and has important potential role in cardiac imaging in the fetus.

Transverse Velocity Field Measurements in High-resolution Solar Images Based on Deep Learning

To address the problem of the low accuracy of transverse velocity field measurements for small targets in highresolution solar images,we proposed a novel velocity field measurement method for high-resolution solar images based on PWCNet.This method transforms the transverse velocity field measurements into an optical flow field prediction problem.We evaluated the performance of the proposed method using the Hαand TiO data sets obtained from New Vacuum Solar Telescope observations.The experimental results show that our method effectively predicts the optical flow of small targets in images compared with several typical machine-and deeplearning methods.On the Hαdata set,the proposed method improves the image structure similarity from 0.9182 to0.9587 and reduces the mean of residuals from 24.9931 to 15.2818;on the TiO data set,the proposed method improves the image structure similarity from 0.9289 to 0.9628 and reduces the mean of residuals from 25.9908 to17.0194.The optical flow predicted using the proposed method can provide accurate data for the atmospheric motion information of solar images.The code implementing the proposed method is available on https://github.com/lygmsy123/transverse-velocity-field-measurement.

Convolutional Neural Networks Based Indoor Wi-Fi Localization with a Novel Kind of CSI Images

Indoor Wi-Fi localization of mobile devices plays a more and more important role along with the rapid growth of location-based services and Wi-Fi mobile devices.In this paper,a new method of constructing the channel state information(CSI)image is proposed to improve the localization accuracy.Compared with previous methods of constructing the CSI image,the new kind of CSI image proposed is able to contain more channel information such as the angle of arrival(AoA),the time of arrival(TOA)and the amplitude.We construct three gray images by using phase differences of different antennas and amplitudes of different subcarriers of one antenna,and then merge them to form one RGB image.The localization method has off-line stage and on-line stage.In the off-line stage,the composed three-channel RGB images at training locations are used to train a convolutional neural network(CNN)which has been proved to be efficient in image recognition.In the on-line stage,images at test locations are fed to the well-trained CNN model and the localization result is the weighted mean value with highest output values.The performance of the proposed method is verified with extensive experiments in the representative indoor environment.

正则FI代数的MP滤子与同构基本定理

正则FI-代数是仅基于蕴涵算子在一般集合上建立的逻辑代数,它是BR0-代数和BL-代数的基础逻辑代数。基于经典代数的思想和方法,讨论了正则FI-代数的MP滤子与同构基本定理。引入正则FI-代数中MP滤子的概念,并讨论了其基本性质,给出了正则FI-代数中包含任意子集的最小MP滤子的构造方法;讨论了正则FI-代数的MP滤子和同余关系之间的内在联系;给出了正则FI-代数的同构基本定理。

改进MixNet的CSI图像指纹室内定位方法

为了提升信道状态信息(channel state information,CSI)指纹室内定位的性能,提出了一种改进MixNet的CSI图像指纹室内定位方法.在离线阶段,通过选择定位参考点(reference point,RP)处信号强度指示(received signal strength indication,RSSI)最强的3个接入点(access point,AP),提取其CSI数据并转换为图像;然后利用改进的MixNet模型对图像进行训练并保存模型.其中改进的MixNet引入了坐标注意力(coordinate attention,CA)和残差连接.首先,将MixNet-s中的SE(squeeze-and-excitation)注意力替换为CA,以增强网络的信息表示能力并更精确地获取CSI图像指纹特征.其次,根据MixNet-s模型的特点构建残差连接,以增强网络的表示能力并防止过拟合.最后,通过减小网络深度确保所有网络层得到充分训练;在线阶段,采集目标设备的CSI数据并转换为图像,输入已训练好的改进MixNet模型(命名为MixNet-CA);最后利用加权质心算法根据模型输出的概率值估计目标设备的最终位置.提出方法在室内环境中进行了验证,达到了0.3620 m的平均定位误差.

北京市自然地理实体采集关键技术研究及实践

本文以2022年城市地图(City Mapper-2)软件的框幅式立体影像、国土变更调查数据为主要数据源,对北京市自然地理实体数据生产流程和关键技术进行研究,结合怀柔科学城自然地理实体生产工程实践,详细阐述了山体与水系图元采集、农林用地与土质存量数据转换及高程赋值、实体关系构建等关键技术的实现过程,形成了一套切实可行的自然地理实体构建工艺流程。结果表明,本文探索的技术路线为同类型自然地理实体生产项目提供技术参考,构建的地理实体平面精度为0.21 m,高程精度为0.26 m,有效地保证了产品精度、时效性,推动了传统单一比例尺数据库向实体化、一体化时空数据库转变。

医学影像技术专业影像电子学基础课程分层教学探讨

在高职院校扩大招生的背景下,文章通过对医学影像技术专业学生进行问卷调查与影像电子学基础课程课程测评的方式,调查与了解学生的课程学习情况和实际需求,以人才培养方案对医学影像技术专业基础知识的要求为着力点,探索新的影像电子学基础分层教育模式。不同层次学生的课程学习情况和实际需求不同,为达到相同的人才培养效果,文章提出可展开教学分层、教学目标分层、教学内容分层、学习过程分层、考核方法分层和评价分层,切实提升学生的专业基础能力和知识水平。

Radiological diagnosis of duodenocaval fistula:A case report and literature review

Duodenocaval fistula(DCF) is an uncommon but lethal clinical entity.The high mortality has been attributed to the difficulty of diagnosis before attempts at definitive therapy.In this case report,we describe a patient with a series of computed tomography(CT) examinations over a 2-mo period in hospital.A low-density air bubble appeared in the inferior vena cava(IVC) on the second day in hospital and became clear on day 19,and gradually enlarged.Magnetic resonance imaging(MRI) also clearly demonstrated a high-signal enteric contrast medium or thrombus and signal-void air bubbles in the IVC.However,cavography did not show the filling defect.We suggest that noninvasive CT and MRI should be chosen as a first-line investigation,and IVC,including the surrounding structures,should be carefully reviewed on images if DCF is clinically considered.

Clinical forensic imaging and fundamental rights in Austria

Clinical forensic imaging encompasses the diverse application of imaging procedures that serve the same purpose:to enable the analysis and investigation of criminal activities and consequences of a crime.All kinds of imaging techniques and their corresponding images can be subsumed under“forensigraphy”,a more comprehensive term for forensic imaging created by the Ludwig Boltzmann Institute for Clinical Forensic Imaging in Graz,Austria.As the word forensigraphy suggests,criminal imaging material should be of use in forensic investigations.Ideally,this can lead to new findings that would not have been revealed without the application of imaging techniques and are moreover admissible as evidence in criminal proceedings.However,the admissibility of evidence can only be facilitated through the implementation of clinical forensic imaging techniques into the forensic routine case work,which requires a precise pre-analysis of the corresponding legal framework.Because taking and displaying internal images of a person’s body touches upon various aspects of one’s physical and psychological integrity,imaging methods in general and clinical forensic imaging methods especially have a strong impact on and interfere regularly with the fundamental rights of the concerned person.Particularly with regard to a possible medical context,certain legal regulations have to be taken into account.Therefore,this paper examines forensic imaging in the field of radiological forensigraphy,specifically its in vivo(i.e.clinical)application.It is designed to enlighten readers as to the great significance of legal barriers that emerge from fundamental rights,as laid down in the European Convention on Human Rights(ECHR),when dealing with clinical forensic imaging.As a result,the legal framework of clinical forensic imaging procedures are comprehensively described,the relevant fundamental rights,especially the right to respect for private and family life,the right to data protection and certain procedural guarantees,are concisely presented to further raise awareness regarding the importance of fundamental rights.

Study and application analysis of random noise adaptive morphological fi lter algorithm reconstruction for seismic signals

In this study,a new adaptive morphological filter is developed based on the mathematical morphology algorithm and characteristics of the subtle differences in the waveform morphology in seismic data.The algorithm improves the traditional morphological dilation and corrosion operations.In this study,we propose a multiscale adaptive operator based on the principle of morphological structural“probes”and present the corresponding mathematical proof.Simulation experiments and actual seismic data processing results show that compared with traditional morphological filters,the constructed OCCO-based multistructure adaptive morphological filter can suppress noise to the greatest extent.Moreover,it can effectively improve the SNR of the images,and offers great application prospects.

基于Wi-Fi Direct的农业图像采集系统设计

农业大棚所处环境偏远,通用的无线网基站难以很好覆盖,导致信号不强、通信不畅。提出了一种基于Wi-Fi Direct无线通信的图像采集系统。该系统采用Linux操作系统与ARM9S3C2440作为软硬件开发平台,将CMOS OV9650摄像头作为图像传感器,利用Wi-Fi Direct无线通信将采集到的图像信息发送至远程监控终端,上位机监控界面用LabVIEW开发。给出了图像采集系统的软硬件设计方案及测试结果。结果表明,该系统硬件结构小、运行稳定,最大优势是传输速率快,不用路由器就能组网实现远程图像的实时传输,在农业方面具有一定的实用价值。

基于连续图像深度学习的Wi-Fi人体行为识别方法

针对基于深度学习的Wi-Fi人体行为识别技术存在抗噪声能力弱、信号尺寸不兼容和特征提取不充分等问题,提出了一种基于连续图像深度学习的识别方法。首先把时变Wi-Fi信号重构为若干个连续图像帧,确保输入尺寸一致;进而设计低秩分解算法,对噪声湮没的关键运动信息进行分离;同时提出一种时间域和空间域信息融合的深度模型,自动捕捉变长图像序列的时空域特征,并在WiAR数据集和自主采集数据集上对所提方法进行验证。实验结果表明,所提方法平均识别精度分别为0.94和0.96,具备普适场景下的高精度和稳健性。

GEOMETRIC PROPERTIES FOR GAUSSIAN IMAGE OF SUBMANIFOLDS IN S^(n+p)(1)

The geometric properties for Gaussian image of submanifolds in a sphere are investigated. The computation formula, geometric equalities and inequalities for the volume of Gaussian image of certain submanifolds in a sphere are obtained.

基于Wi-Fi传输模块优化的GIS设备数字成像系统设计

为准确检测GIS设备的缺陷状态,凸显GIS设备数字成像细节,提升GIS设备缺陷精度与效率,设计基于Wi-Fi传输模块优化的GIS设备数字成像系统。应用X射线机和成像板同步升降装置调节X摄像机和成像板位置,通过Wi-Fi信号可控制同步升降装置的位置、控制数字成像系统的数据采集与图像传输,引入Wi-Fi网络通信信息传输效率优化方法,提高GIS设备数字成像信息传输效率。实验结果验证:该系统对多种GIS设备的数字成像效果显著,成像时设备缺陷细节明显;对GIS设备缺陷的漏检率降低,信息传输效率与吞吐量得以优化。

基于STM32微控制器的Wi-Fi图传系统设计

文章提出一套基于STM32F407微控制器的无线图传系统,微控制器上实现Web服务器功能,通过Wi-Fi硬件模块实现较高帧率的无线图像传输。原型系统通过连接的摄像头对彩色图像进行采集和压缩,并最终使用Wi-Fi无线传输数据到上位机软件或者浏览器直接显示采集到的图像,传输图像标准为QVGA,分辨率大小为320*240,图像传输帧率达到每秒15帧,整套系统成本约为150元。

一种基于Wi-Fi图像控制的采摘机械手设计

研究了一种基于Wi-Fi视频回传定位的电动手动模块化采摘机械手,利用手机app监测装置实时传输视频信息到显示屏,协助采摘者检查果子是否合格、定位是否可靠;通过控制主电机带动丝杠的运动角度,调节双向伸缩杆的长度适应采摘高度,并触发舵机完成剪切动作。该机械手使用方便、动作灵敏、采摘效率高,具有优良的经济性。另外,在有助于降低采摘工作危险程度的同时,还能增加采摘乐趣。

基于Wi-Fi图像传输技术的微型空间外差光谱仪设计

设计了一种基于空间外差光谱技术微型光谱仪,它可以同时获得高通量以及高光谱分辨率。为了满足微型光谱仪在户外环境下便携性、操作便捷的使用要求,将基于ARM11和Linux系统的单板相机与Android嵌入式系统相结合,通过Wi-Fi图像传输模块将采集的光谱信号传输到手机上,并在手机上直接对光谱数据进行处理。该系统无需电脑的接入,提高了微型光谱仪使用的便捷性。

爱恨纠缠的他者想象——论人类世气候小说《未来部》的中国形象

诸多西方作家高度关注21世纪的中国,并将其融入文学创作,这尤为体现在近些年英语文坛蓬勃发展的气候小说中。本文以美国当代著名科幻作家金·斯坦利·罗宾逊2020年出版的《未来部》为研究对象,聚焦其中的中国形象塑造。论文借鉴心理学中的“心智三维度”“双重态度”等理论概念,探讨《未来部》呈现的整体中国形象,考察作家的中国观,并剖析作家塑造中国形象的深层发生机制。研究认为,罗宾逊笔下的中国具有很强的时代感、鲜活感和现实主义色彩;具有高度政治自觉的罗宾逊将中国塑造为人类世时代的“他者”,这根植于西方对中国的态度,对中国他者的态度以“爱恨纠缠”为鲜明特征,这同西方既要依靠中国、又不完全信任中国的矛盾态度密切相关。此个案研究对揭示西方对21世纪的中国的认知具有一定的借鉴价值,对我们更好实现“可信、可爱、可敬的中国形象”的塑造也具有一定的启发意义。

基于鲸鱼优化和模糊聚类的林火图像分割

鲸鱼优化算法(Whale Optimization Algorithm,WOA)收敛速度快、精度高,在寻找最优解的过程中效率较高,对其进行一定的改进,利用改进的鲸鱼优化算法来优化核模糊聚类算法中聚类中心的生成过程,提出一种基于改进鲸鱼优化的核模糊C均值聚类算法(Impoved Whale Optimization Fuzzy C-Means Clustering,IWOA_KFCM)。为了验证算法的性能,采用定性和定量两种分析方法对基于改进鲸鱼的核模糊聚类算法进行了测评,实验结果证明改进鲸鱼的核模糊聚类算法具有较高的聚类准确率,同时时间效率也比较高。将基于改进鲸鱼的核模糊聚类算法应用于林火图像的分割问题上,获得了更为准确的分割阈值和更高的分割效率,具有较强的工程实用性。

中国传统形象元素在手办中的应用

以中国传统造型形象元素为研究对象,探讨中国传统文化在手办设计制作中的应用,结合实践案例分析手办的角色造型、动作设计、表情表达等方面的独特表现。