Three-dimensional positions of scattering centers reconstruction from multiple SAR images based on radargrammetry

A method and procedure is presented to reconstruct three-dimensional(3D) positions of scattering centers from multiple synthetic aperture radar(SAR) images. Firstly, two-dimensional(2D) attribute scattering centers of targets are extracted from 2D SAR images. Secondly, similarity measure is developed based on 2D attributed scatter centers' location, type, and radargrammetry principle between multiple SAR images. By this similarity, we can associate 2D scatter centers and then obtain candidate 3D scattering centers. Thirdly, these candidate scattering centers are clustered in 3D space to reconstruct final 3D positions. Compared with presented methods, the proposed method has a capability of describing distributed scattering center, reduces false and missing 3D scattering centers, and has fewer restrictionson modeling data. Finally, results of experiments have demonstrated the effectiveness of the proposed method.

New Three-Dimensional Assessment Model and Optimization of Acoustic Positioning System

This paper addresses the problem of assessing and optimizing the acoustic positioning system for underwater target localization with range measurement.We present a new three-dimensional assessment model to evaluate the optimal geometric beacon formation whether meets user requirements.For mathematical tractability,it is assumed that the measurements of the range between the target and beacons are corrupted with white Gaussian noise with variance,which is distance-dependent.Then,the relationship between DOP parameters and positioning accuracy can be derived by adopting dilution of precision(DOP)parameters in the assessment model.In addition,the optimal geometric beacon formation yielding the best performance can be achieved via minimizing the values of geometric dilution of precision(GDOP)in the case where the target position is known and fixed.Next,in order to ensure that the estimated positioning accuracy on the region of interest satisfies the precision required by the user,geometric positioning accuracy(GPA),horizontal positioning accuracy(HPA)and vertical positioning accuracy(VPA)are utilized to assess the optimal geometric beacon formation.Simulation examples are designed to illustrate the exactness of the conclusion.Unlike other work that only uses GDOP to optimize the formation and cannot assess the performance of the specified size,this new three-dimensional assessment model can evaluate the optimal geometric beacon formation for each dimension of any point in three-dimensional space,which can provide guidance to optimize the performance of each specified dimension.

Effects of the initiation position on the damage and fracture characteristics of linear-charge blasting in rock

To study the effects of the initiation position on the damage and fracture characteristics of linear-charge blasting, blasting model experiments were conducted in this study using computed tomography scanning and three-dimensional reconstruction methods. The fractal damage theory was used to quantify the crack distribution and damage degree of sandstone specimens after blasting. The results showed that regardless of an inverse or top initiation, due to compression deformation and sliding frictional resistance, the plugging medium of the borehole is effective. The energy of the explosive gas near the top of the borehole is consumed. This affects the effective crushing of rocks near the top of the borehole, where the extent of damage to Sections Ⅰ and Ⅱ is less than that of Sections Ⅲ and Ⅳ. In addition, the analysis revealed that under conditions of top initiation, the reflected tensile damage of the rock at the free face of the top of the borehole and the compression deformation of the plug and friction consume more blasting energy, resulting in lower blasting energy efficiency for top initiation. As a result, the overall damage degree of the specimens in the top-initiation group was significantly smaller than that in the inverse-initiation group. Under conditions of inverse initiation, the blasting energy efficiency is greater, causing the specimen to experience greater damage. Therefore, in the engineering practice of rock tunnel cut blasting, to utilize blasting energy effectively and enhance the effects of rock fragmentation, using the inverse-initiation method is recommended. In addition, in three-dimensional(3D) rock blasting, the bottom of the borehole has obvious end effects under the conditions of inverse initiation, and the crack distribution at the bottom of the borehole is trumpet-shaped. The occurrence of an end effect in the 3D linear-charge blasting model experiment is related to the initiation position and the blocking condition.

Integration system research and development for three-dimensional laser scanning information visualization in goaf

An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.

Methods for Setting up a Three-Dimensional Industrial Surveying System of “Building Blocks Type”

This paper is to advance some relevant techniques to set up a three-dimensional industrial surveying system of “building blocks type”, making use of the electronic theodolite, standard ruler and portable computer.

Interpreter’s Position in the Process of Interpretation

With the rapid development of globalization, the whole world interweaves unprecedentedly. The frequent global communication is in desperate need of qualified translators and interpreters which draws great attention and invokes discussion about the standard of translation. Is the widely acknowledged criterion—neutral position a possible and necessary regulation to justify professional translators? This essay will illustrate that the interpreters influenced by environment, culture and other factors can’t perform with an absolute neutral position. Furthermore, the creativity of interpreters, who conduct heuristic work instead of algorithmic and reduplicated work, play a pivotal role in qualified work and their long-term development on the basis of Skopos Theory and classical examples, which testifies that it is improper to regard neutral position as a significant standard to evaluate the quality of interpreters.

Three-dimensional Information Decoupling System Based on PSD and Deviation Correction

Three-dimensional Information Decoupling System Based on PSD were designed based on LabVIEW, in order to achieve precision, timeliness, reliability require-ments of the PSD used in the ATP system of Satellite Earth quantum communication. Firstly, the laser light source was driven by a stepper motor to scan on the PSD photosensitive surface, and the voltage value was collected and calculated to get the spot position. Analyzing the cause of nonlinear, a mathematical model was built between the actual value and the measured value by using binary quadratic polynomial method, PSD nonlinear correction function would be got. Then, the object micro displacement and angle offset were measured by combining optical triangulation method, and the error of the measurement results was corrected. Experimental results showed that, after the correction, the measuring deviation could be significantly reduced, the PSD performance calibration requirements was achieved, the efficiency of the system was developed greatly by using LabVIEW.

On capped Higgs positivity cone

The Wilson coefficients of the standard model effective field theory are subject to a series of positivity bounds.It has been shown that while the positivity part of the ultraviolet(UV)partial wave unitarity leads to the Wilson coefficients living in a convex cone,further including the nonpositivity part caps the cone from above.For Higgs scattering,a capped positivity cone was obtained using a simplified,linear unitarity condition without utilizing the full internal symmetries of Higgs scattering.Here,we further implement stronger nonlinear unitarity conditions from the UV,which generically gives rise to better bounds.We show that,for the Higgs case in particular,while the nonlinear unitarity conditions per se do not enhance the bounds,the fuller use of the internal symmetries do shrink the capped positivity cone significantly.

Effects of lower body positive pressure treadmill on functional improvement in knee osteoarthritis:A randomized clinical trial study

BACKGROUND Knee joint pain and stiffness are the two main symptoms of knee osteoarthritis(OA)and thus restrict a patient’s activities,such as walking and walking up and downstairs.The lower body positive pressure(LBPP)treadmill as one of the emerging body weight support system devices brings new hope for exerciserelated rehabilitation for knee OA patients.AIM To investigate the biomechanical effects and the subjective clinical assessment of LBPP treadmill walking exercise when compared with conventional therapy in mild to moderate knee OA patients.METHODS Eighteen patients with mild-to-moderate knee OA were recruited in this randomized controlled trial(RCT)study.The eligible knee OA patients were randomly assigned to two groups:LBPP and control groups.The patients in the LBPP group performed an LBPP walking training program for 30 min/session per day,6 d per week for 2 wk whereas the patients in the control group performed walking on the ground for the same amount.All patients underwent clinical assessments and three-dimensional gait analysis at pre-and 2-wk post-treatment.RESULTS The Western Ontario and McMaster Universities Arthritis Index and visual analog scale scores in both the LBPP group and control group were found to decrease significantly at the post-treatment point than the pre-treatment point(LBPP:70.25±13.93 vs 40.50±11.86;3.88±0.99 vs 1.63±0.52;control:69.20±8.88 vs 48.10±8.67;3.80±0.79 vs 2.60±0.70,P<0.001).Moreover,compared with the control group,the LBPP group showed more improvements in walking speed(P=0.007),stride length(P=0.037),and knee range of motion(P=0.048)during walking,which represented more improvement in walking ability.CONCLUSION The results of our RCT study showed that the LBPP group has a greater effect on improving gait parameters than the conventional group,although there was no significant advantage in clinical assessment.This finding indicates that LBPP treadmill walking training might be an effective approach for alleviating pain symptoms and improving lower extremity locomotion in mild to moderate knee OA patients.

The application of 3D printing in the development of RECIST standard for evaluating tumor efficacy

Three-dimensional(3D)printing technology,as a novel technical method,can convert conventional computed tomography(CT)or magnetic resonance imaging(MRI)scans to computer-aided design files and develop a 2D spatial structure into a 3D imaging structure.In recent years,the technology has been widely used in numerous areas,including head and neck surgery,orthopedics,and bio-medicinal research.This article uses examples of 3D printed tumor models to develop Response Evaluation Criteria In Solid Tumors(RECIST)standards to evaluate the changes in tumors.RECIST standard is currently recognized as the standard for assessment of chemotherapy.Under the RECIST standard,changes occurring in tumors before and after the surgery,are evaluated.The assessment depends upon a CT evaluation of the changes in the lesions with the largest diameters.In addition,the disease progression and stability of remission is also assessed.Three-dimensional printing technology is more intuitive in the evaluation of changes to human tumors following chemotherapy and targeted therapy.However,a few reports are available.

The Ugly Beauty Standard: What can Fashion Industry Do?

The ugly beauty standard is caused by the fashion industry as people tend to pay more attention to being skinny and achieving the perfect body.More and more people are sacrificing their health and choose to do plastic surgeries.The fashion industry can also take some measures to get rid of the beauty standard by spreading the different brands that design clothes for different body types,and making the brand that is inclusive for all body size.The future fashion industry should be inclusive and diverse,and help people find the beautiful side and love themselves.

手术沙滩椅体位摆置标准作业程序的建立及应用

目的研究手术沙滩椅体位(beach chair position,BCP)摆置标准作业程序(standard operation procedure,SOP)的建立及应用。方法采用方便抽样的方法,选取2020年10—12月厦门大学附属第一医院收治的16例肩关节镜手术患者为对照组,以对等原则选取2021年1—3月收治的16例患者为观察组。对照组按常规手术体位摆置;观察组按BCP摆置SOP实施摆置。比较2组摆置时间、团队协作熟悉度及医生满意度,并就对手术BCP摆置SOP进行评价。结果观察组手术体位摆置时间为(471.81±52.41)s,短于对照组的(719.13±66.94)s(P<0.05);观察组手术医生的满意度高于对照组,手术团队协作熟悉度评分高于对照组,差异有统计学意义(P<0.05)。2组麻醉医生满意度比较,差异无统计学意义(P>0.05)。团队成员对手术BCP摆置SOP评价认可度均较高。结论手术BCP摆置SOP的建立及应用使手术体位护理规范化、标准化、同质化,有效提高手术室护理质量和工作效率。

推进煤矿岗位标准作业流程应用 促进煤矿安全生产形势根本好转

通过分析煤矿现场安全管理长期以来存在的主要问题,发现员工作业规范欠缺是长期困扰煤矿现场安全管理的重要因素之一,认为煤矿岗位标准作业流程是破解煤矿现场安全规范作业难题、保障煤矿安全生产的有效手段。阐述了煤矿岗位标准作业流程的由来,并对近几年煤炭行业在推广应用煤矿岗位标准作业流程过程中取得的主要成效进行了介绍。提出加快流程标准体系建设、加强流程示范引领与学习共享、强化流程科技创新与总结、持续拓展完善流程体系内容等进一步推进煤矿岗位标准作业流程应用的具体举措。

高校全员大安全责任制建设与岗位安全标准化实践探索

国内实验室安全管理水平严重滞后于高校学科建设快速发展步伐与安全环境的要求。通过对新安全生产法等文件解读,开展全员参与、全过程履责的大安全观制度建设,提高实验室管理整体安全性。从安全风险防控系统性视角,构建以岗位作业行为标准化、岗位作业环境标准化及岗位安全信息标准化为主要手段的可目视化标准化管理模式,实现高校实验室安全管理模式由经验粗放型、分散化管理向精细化、目标化、责任制、标准化管理转变;打造全员、全组织安全责任制全过程全覆盖,形成高校全员全方位安全责任内生机制,推动构建“大安全”管理体系,为实验室安全治理体系与治理能力现代化提供有益探索。

新时期煤矿岗位标准作业流程应用探讨

随着我国煤炭工业智能化水平的逐步提升,生产力水平也随之发生变化。针对煤矿岗位标准作业流程如何支撑煤炭行业新质生产力的发展进行了深入探讨,认为煤矿岗位标准作业流程应用将面临智能矿山建设、职业安全健康、机器人替代、新兴岗位出现、多岗位协同作业等方面的挑战,提出了数字化应用、智能化装备落地、系统化培训等发展路径;总结了煤矿岗位标准作业流程在保障安全生产和推动智能化、高效化、绿色化发展中发挥的作用,最后提出未来优化和创新建议。

类型优化视域下中高本一体化标准开发样态与优化框架

开发中高本一体化专业人才培养标准是实现中高本内涵式一体化发展的基本路径,是构建现代职业教育体系、优化职业教育类型定位的应有之义。而职业教育的类型属性是开发中高本一体化专业人才培养标准的起点。当前,一体化专业人才培养标准开发实践虽已初见成效,但仍存在开发主体失衡、内容失真、过程失序等诸多不足,标准的成果质量与类型特征仍有待整体性提升。基于职业教育的类型属性或特征,在专业人才培养标准开发一般性原理与技术的基础之上,针对一体化标准开发的问题样态,分别从开发工作机制、体系逻辑、技术方案不同维度进行优化设计,构成了一体化标准开发的主要实践向度。

一种口腔检查机器人的设计与定位研究

传统的口腔疾病诊断高度依赖医生的临床经验和专业素养,因此创新设计了一种口腔检查机器人样机,采用标准D-H法建模,利用蒙特卡洛法进行工作空间分析,利用五次多项式插值函数对机械手进行轨迹规划,验证了结构设计的合理性。基于Dlib模型设计了口腔状态判断方法,通过分析Astra S相机、机械手和三维空间之间的坐标系转换关系,获取嘴部中心坐标,经重复定位试验得到误差均在±2 mm之内,验证了嘴部定位方法的可行性。

北斗三号仅用作追踪的机载设备适航要求分析

随着北斗三号卫星导航系统服务正式开通,北斗二号相关适航标准已无法满足当前机载设备应用场景需求,严重制约了北斗在民航领域的应用进程,急需开展北斗三号相应标准的研究与制定。针对北斗在民用航空器中应用第1阶段“仅用作航空器追踪”,对北斗二号与北斗三号开展差异性分析,提出标准修订总体方案,综合考虑适航安全性、机载设备应用场景,结合工业实践,根据设备构型提出指标修订方案,形成审定要素及符合性方法建议,为设备研发与适航取证提供标准支持。仿真分析了设备天线增益、卫星可见性等关键参数,验证了所修订技术指标的正确性。

外科住院医师规范化培训后岗位胜任力调查分析

目的 了解住院医师规范化培训(以下简称“住培”)结业后外科住院医师的岗位胜任力情况,为提高外科住培质量和优化培训体系提供参考。方法 采用整群抽样的方式对参加北京市2022年住培结业考核的552名外科住院医师及外科住培基地的348名上级医师进行问卷调查。问卷由一般信息问卷、胜任力调查问卷两部分组成。结果 住院医师在岗位胜任力、临床技能与医疗服务能力、医学知识与终身学习能力、人际沟通能力、团队合作能力、科学研究能力、核心价值观与医生素养能力的自评分均高于上级医师评分(P<0.05)。科学研究能力、信息与管理能力在各维度中处于评分的最后2位。岗位胜任力及各维度的自评分在不同性别、身份、学历、培训年限中的分布比较,差异有统计学意义(P<0.05)。结论 外科住院医师的岗位胜任力在科研能力、信息与管理能力上稍显薄弱,在未来的培训中需加以关注。同时,在培训过程中,应根据不同人员类型特点,继续深化岗位胜任力培训体系。

成人正畸术后美观人群的颅颌面特征和前牙目标位设计

目的 以正畸患者为基础,探究成人正畸术后美观人群的颅颌面特征,并为前牙目标位设计提供参考。方法 从1 055例成人正畸患者中,经过纳入标准、排除标准和术后美学评价,最终纳入338例术后美观人群进行头影测量分析。统计描述术后美观人群的头影测量均值,广义估计方程比较性别、骨性矢状向分类(ANB)的差异,单因素分析评价不同性别中年龄、骨性指标和软组织指标的相关性,多因素分析评价骨组织指标、软组织指标对正畸切牙指标拟合的影响。结果 术后美观人群中,男女性在颅骨和下颌骨长度、下颌骨顺旋程度、骨性颏部突度、上颌切牙唇倾度、上唇厚度、面下1/3高度、鼻部突度差异存在统计学意义。术后美观骨性Ⅰ类人群中,男性和女性的骨性颏部突度差异无统计学意义,男性下唇突度比女性更小,其余性别差异与不区分骨性矢状向分类的美观人群结果一致。男性在不同骨性分类中,上下唇突度、软组织颏部突度差异存在统计学意义,但骨性Ⅱ类比骨性Ⅰ类人群的上唇基底部更薄,骨性Ⅲ类比骨性Ⅰ类人群的下唇面高更大。女性在不同骨性分类中,上唇突度、上唇面高、软组织颏部突度差异存在统计学意义,但骨性Ⅲ类比骨性Ⅰ类人群的上唇基底部更厚。术后美观人群中,男女性的上唇厚度、女性上唇基底部厚度及下唇面高与年龄存在相关性。男性患者上唇突度与后颅底长度、下颌体长度、ANB、上颌骨矢状向长度存在相关性,下唇突度与下颌升支高度、下颌骨顺旋情况、骨性颏部突度存在相关性。女性患者上唇突度与SNA、ANB、上颌骨矢状向长度、下颌骨顺旋情况、骨性颏部突度存在相关性,下唇突度与ANB、下颌骨顺旋情况、骨性颏部突度存在相关性。使用多个骨性指标拟合牙性指标时,男性的牙性指标IMPA和女性的牙性指标G Vert-U1的adjusted R^(2)(分别为0.712、0.795)最大。同时使用多个骨性和软组织指标拟合牙性指标时,男女性的G Vert-U1的adjusted R^(2)(分别为0.836、0.842)最大,其中男性G Vert-U1主要受软组织颏部突度和鼻基底部突度影响,女性G Vert-U1主要受鼻基底部突度和ANB影响。结论 本研究以正畸患者为基础,展示了成人正畸术后美观人群的颅颌面特征,发现了性别、年龄、骨组织与软组织指标的相关性,基于多个骨组织和软组织对牙性指标进行拟合,为正畸前牙目标位美学设计提供参考。