基于小波分析和三次有理Bézier样条的曲线光顺算法

给出了一种先对初始曲率进行小波分解,再用变步长的方法选取待插值点,最后利用G2连续的三次有理Bézier样条插值重建出光顺的平面曲线的方法.这种方法能适应逆向工程中处理海量数据的重建要求,可以直接处理含噪声的数据.采取变步长选取待插值点,避免选用坏点,提高了光顺效果.算例表明该光顺方法得到了良好的光顺效果,具有很强的适用性.     

基于BERT-LDA模型的新冠肺炎疫情网络舆情演化仿真

构建大规模网络舆情演化仿真模型,对新冠疫情武汉重灾区与全国其他地区采取差异化的应急管理和舆情疏导具有指导价值.为实现主题细粒度的舆情情感演化仿真,将LDA(LatentDirichlet Allocation)主题模型与BERT(Bidirectional Encoder Representations from Tr...     

Study of an inchworm-like micro-robot

A micro-robot with 4 DOFs is presented in this paper. An inchworm-like biped mechanical structure is selected with the advantages of small size and minimal weight. It can walk on wall as an inchworm with two different locomotion modes such as crawling and overturn. With rotation mode, this robot can change it＇ s motion direction. The robot can also transit between different surfaces. The kinematics model of the robot has been analyzed. A DSP based embedded controller is used for minimal power consumption and efficient control. The micro-robot can move flexibly and fit complicated un-structural environment well.     

微重力下管内凝结换热性能的研究

为了预测失重条件下航天飞行器中冷凝器的传热性能，提出了一种研究微重力场中管内凝结换热过程的方法，建立了管内环状流域层流凝结换热的数理模型。改变重力加速度ｇ值进行仿真计算，随着ｇ值的减小，凝结液膜变厚，使凝结换热恶化，例如在相同冷却条件下，当进口蒸气Ｒｅ数为１０４时，ｇ＝０和ｇ＝９．８ｍ／ｓ２环境下的平均冷凝Ｎｕ将降低３０％。并以重力场中垂直管内凝结换热的实验结果对模型进行了间接的检验。给出了预测零重力环境中管内平均凝结换热系数的准则关联式，可供航天器热控系统的热分     

可穿戴技术应用于术后监控和康复的现状分析

 术后健康监控过程能够保障在生命体征出现异常情况时可以进行及时处理,同时术后康复训练及效果评估也需要有效的工具进行支持,可穿戴技术的出现和发展,为这些需求的实现提供了相应的技术保障。本文利用国内外学术数据库,对可穿戴技术在术后监控、术后康复训练方面的研究和应用相关文献进行了收集和整理,综述了可穿戴技术在各类外科领域的应用情况,包括基本功能、技术原理、使用方法及对其进行效果评价。结果表明,可穿戴技术在术后的应用已涉及显微外科、矫形外科、普通外科、心胸外科、神经外科等外科方向,但其应用尚处于研究探索阶段。未来需要更多关于可穿戴技术用于术后健康监控和康复训练评估的可行方法和临床验证工作的研究,以使它真正满足病人术后在医院和家庭进行健康监控和康复训练的需要。     

敏捷成像卫星时间依赖型调度问题、模型与算法

针对敏捷成像卫星时间依赖型调度问题展开研究,将时间依赖调度与敏捷成像卫星调度相结合,在分析主要约束条件的基础上,建立了问题的数学模型.根据成像质量随成像时间动态变化的特点,设计了随时间动态变化的收益函数,并将轮盘赌思想和时间窗口裁剪概念引入到求解方法中,提出了一种启发式算法.实验数据显示,通过对时间依赖的考虑,更多的任务能够在最佳观测时刻点附近成像,同时也表明了模型的合理性以及算法的有效性.     

The design of the robot assisted magnetic resonance imaging guidance for minimally invasive surgery system

assisted Minimally lnvasive Surgery (MIS) is one of the rapidest developing directiorls in the current surgical reahn. Magnetic Resonance Imaging (MRI) is an optimal imaging modality which was applied in MIS in recent years. By combination of precise positioning to the target by intra-operative MRI guided surgery and dexterous motion by the robot, safe and smooth operation is expected to be peffurmed.An overview of the MR I-guided robotic system for MIS is offered. The design of the intra-operative MR scalmer system is described. The MR-compatible robotic system is carefully desigaled for safety and sterilization issues. This system unifies image information from open MRI, an optical endoscope and conventional vital-sign detectors. It helps and guides the surgeon and other medical staffs so they can make the right decisions. The high-performance manipulator can mimic the movement of the surgeon‘ s hand precisely. And the analysis for active and passive interventional surgical instrument tracking is provided.     

A novel 5-DOF exoskeletal rehabilitation robot system for upper limbs

A novel 5-DOF exoskeletal rehabilitation robot for upper limbs of hemiplegic patients caused bystroke is proposed in this paper.Its hardware structure is introduced and the control methods are ana-lyzed.To implement intelligent and interactive rehabilitation exercises,motion intention of patients' up-per limb is introduced into control methods of rehabilitation exercises.In passive motions,according tothe character of unilateral impaired,multi-channels surface electromyogram(sEMG)signals of patients'hea...     

基于信息熵与未确知测度的煤炭企业经济效益综合评价模型研究

从量的方面客观、有效地研究煤炭企业经济效益的状况,是煤炭企业持续健康发展的必然要求。本文在对现有评价方法研究的基础上,建立煤炭企业经济效益综合评价指标体系,引入信息熵理论．通过熵度量法对量化后的指标体系进行约筒,在此基础上,应用未确知测度模型对煤炭企业经济效益进行综合评价。最后,通过实例给出模型实现的具体过程,验证模型的可行性与有效性。     

An effective algorithm for needle tip displacement compensation in robot-assisted percutaneous surgery

This paper presents an automatic compensation algorithm for needle tip displacement in order to keep the needle tip always fixed at the skin entry point in the process of needle orientation in robot-assisted percutaneous surgery.The algorithm, based on a two-degree-of-freedom (2-DOF) robot wrist (not the mechanically constrained remote center of motion (RCM) mechanism) and a 3-DOF robot arm, firstly calculates the needle tip displacement caused by rotational motion of robot wrist in the arm coordinate frame using the robotic forward kinematics, and then inversely compensates for the needle tip displace-ment by real-time Cartesian motion of robot arm.The algorithm achieves the function of the RCM and eliminates many mechanical and virtual constraints caused by the RCM mechanism.Experimental result demonstrates that the needle tip displacement is within 1 mm in the process of needle orientation.