On a Compound Poisson Risk Model Perturbed by Brownian Motion with Variable Premium and Tail Dependence between Claims Amounts and Inter-Claim Time

This paper considers the compound Poisson risk model perturbed by Brownian motion with variable premium and dependence between claims amounts and inter-claim times via Spearman copula. It is assumed that the insurance company’s portfolio is governed by two classes of policyholders. On the one hand, the first class where the amount of claims is high, and on the other hand, the second class where the amount of claims is low, this difference in claim amounts has significant implications for the insurance company’s pricing and risk management strategies. When policyholders are in the first class, they pay an insurance premium of a constant amount c1 and when they are in the second class, the premium paid is a constant amount c2 such that c1 > c2. The nature of claims (low or high) is measured via random thresholds . The study in this work will focus on the determination of the integro-differential equations satisfied by Gerber-Shiu functions and their Laplace transforms in the risk model perturbed by Brownian motion with variable premium and dependence between claims amounts and inter-claim times via Spearman copula. .

A coherency function model of ground motion at base rock corresponding to strike-slip fault

At present, the method to study spatial variation of ground motions is statistic analysis based on dense array re-cords such as SMART-1 array, etc. For lacking of information of ground motions, there is no coherency function model of base rock and different style site. Spatial variation of ground motions in elastic media is analyzed by deterministic method in this paper. Taking elastic half-space model with dislocation source of fault, near-field ground motions are simulated. This model takes strike-slip fault and earth media into account. A coherency func-tion is proposed for base rock site.

Bessel Function and Damped Simple Harmonic Motion

A glance at Bessel functions shows they behave similar to the damped sinusoidal function. In this paper two physical examples (pendulum and spring-mass system with linearly increasing length and mass respectively) have been used as evidence for this observation. It is shown in this paper how Bessel functions can be approximated by the damped sinusoidal function. The numerical method that is introduced works very well in adiabatic condition (slow change) or in small time (independent variable) intervals. The results are also compared with the Lagrange polynomial.

MULTI-DIMENSIONAL GEOMETRIC BROWNIANMOTIONS, ONSAGER-MACHLUP FUNCTIONS, AND APPLICATIONS TO MATHEMATICAL FINANCE

The solutions of the following bilinear stochastic differential equation are studied [GRAPHICS] where A(t)(k), B-t are (deterministic) continuous matrix-valued functions of t and w(1) (t),..., w(m) (t) are m independent standard Brownian motions. Conditions are given such that the solution is positive if the initial condition is positive. The equation the most probable path must satisfy is also derived and applied to a mathematical finance problem.

Numerical Green’s function method:Application to quantifying ground motion variations of M7 earthquakes

The concept of ＂numerical Green’s functions＂ （NGF or Green’s function database） is developed. The basic idea is： a large seismic fault is divided into subfaults of appropriate size, for which synthetic Green’s functions at the surface （NGF） are calculated and stored. Consequently, ground motions from arbitrary kinematic sources can be simulated, rapidly, for the whole fault or parts of it by superposition. The target fault is a simplified, vertical model of the Newport-Inglewood fault in the Los Angeles basin. This approach and its functionality are illustrated by investigating the variations of ground motions （e.g. peak ground velocity and synthetic seismograms） due to the source complexity. The source complexities are considered with two respects： hypocenter location and slip history. The results show a complex behavior, with dependence of absolute peak ground velocity and their variation on source process directionality, hypocenter location, local structure, and static slip asperity location. We concluded that combining effect due to 3-D structure and finite-source is necessary to quan- tify ground motion characteristics and their variations. Our results will facilitate the earthquake hazard assessment projects.

Research on motion compensation method based on neural network of radial basis function

The machining precision not only depends on accurate mechanical structure but also depends on motion compensation method. If manufacturing precision of mechanical structure cannot be improved, the motion compensation is a reasonable way to improve motion precision. A motion compensation method based on neural network of radial basis function(RBF) was presented in this paper. It utilized the infinite approximation advantage of RBF neural network to fit the motion error curve. The best hidden neural quantity was optimized by training the motion error data and calculating the total sum of squares. The best curve coefficient matrix was got and used to calculate motion compensation values. The experiments showed that the motion errors could be reduced obviously by utilizing the method in this paper.

Research on Key Technologies of Hand Function Rehabilitation Training Evaluation System Based on Leap Motion

This paper proposes an immersive training system for patients with hand dysfunction who can perform rehabilitation training independently. The system uses Leap Motion binocular vision sensors to collect human hand information, and uses the improved PCA (Principal Component Analysis) to perform data fusion on the real-time data collected by the sensor to obtain more hands with fewer principal components, and improve the stability and accuracy of the data. Immediately, the use of improved SVM (Support Vector Machine) and KNN (K-Nearest Neighbor Algorithm) for gesture recognition and classification is proposed to enable patients to perform rehabilitation training more effectively. Finally, the effective evaluation results of the rehabilitation effect of patients by the idea of AHP (Analytic Hierarchy Process) are taken as necessary reference factors for doctors to follow up treatment. Various experimental results show that the system has achieved the expected results and has a good application prospect.

Leap Motion-based virtual reality training for improving motor functional recovery of upper limbs and neural reorganization in subacute stroke patients

Virtual reality is nowadays used to facilitate motor recovery in stroke patients. Most virtual reality studies have involved chronic stroke patients; however, brain plasticity remains good in acute and subacute patients. Most virtual reality systems are only applicable to the proximal upper limbs （arms） because of the limitations of their capture systems. Nevertheless, the functional recovery of an affected hand is most difficult in the case of hemiparesis rehabilitation after a stroke. The recently developed Leap Motion controller can track the fine movements of both hands and fingers. Therefore, the present study explored the effects of a Leap Motion-based virtual reality system on subacute stroke. Twenty-six subacute stroke patients were assigned to an experimental group that received virtual reality training along with conventional occupational rehabilitation, and a control group that only received conventional rehabilitation. The Wolf motor func- tion test （WMFT） was used to assess the motor function of the affected upper limb; functional magnetic resonance imaging was used to measure the cortical activation. After four weeks of treatment, the motor functions of the affected upper limbs were significantly improved in all the patients, with the improvement in the experimental group being significantly better than in the control group. The action perfor- mance time in the WMFT significantly decreased in the experimental group. Furthermore, the activation intensity and the laterality index of the contralateral primary sensorimotor cortex increased in both the experimental and control groups. These results confirmed that Leap Motion-based virtual reality training was a promising and feasible supplementary rehabilitation intervention, could facilitate the recovery of motor functions in subacute stroke patients. The study has been registered in the Chinese Clinical Trial Registry （registration number： ChiCTR-OCH- 12002238）.

正念减压疗法结合适度锻炼对强直性脊柱炎患者康复效果的影响

目的讨论正念减压疗法结合适度锻炼对强直性脊柱炎患者康复效果的影响。方法按随机数字表法将2021年4月至2023年4月在惠州市中心人民医院风湿免疫科住院的118例强直性脊柱炎患者分为对照组和观察组,各59例。对照组给予常规干预,观察组基于常规干预给予正念减压疗法结合适度锻炼干预,并比较2组的干预效果。结果干预1个月后,观察组的枕墙距和指地距均小于对照组,Schober试验距离和胸廓活动度范围均较对照组增加(P均<0.05),且2组均较入院时改善(P均<0.05)。干预1个月后,观察组的强直性脊柱炎功能指数量表各项评分均低于对照组,健康调查量表36各项评分均高于对照组(P均<0.05),且2组均优于入院时(P均<0.05)。结论正念减压疗法结合适度锻炼有助于改善强直性脊柱炎患者的脊柱活动度、躯体功能和生活质量。

基于正余弦函数设计位移运动算法的研究与实现

为实现机床加工运动过程中算法规划能输出连续的运动指令,提高位置控制精度,文章基于正余弦函数值周期连续变化的特性,设计出位移运动指令随时间连续变化的算法模型并进行公式推导。结合Matlab对算法的规划细节进行仿真分析,得到算法规划的控制指令平稳且连续,证明了算法模型建立与公式推导过程的正确性。选择机床加工PCB覆铜板运动过程为试验研究对象,使用激光干涉仪对机床加工实际位移距离进行测量,测得采用所设计的位移运动算法进行运动过程规划,位置控制精度能达到1.788μm,验证了位移运动算法的正确性。

肌内效贴对前交叉韧带重建后康复疗效的Meta分析

目的:一些研究显示肌内效贴在提升前交叉韧带重建后患者肌肉力量、改善关节稳定性、减轻疼痛及水肿方面具有积极效应,然而现有研究关于肌内效贴的临床疗效存在相互矛盾的结果。文章采用Meta分析方法,系统评价肌内效贴对前交叉韧带重建术后康复疗效的影响。方法:应用计算机检索PubMed、Web of Science、Embase、The Cochrane Library、EBSCO、中国知网、万方、维普数据库,搜集有关肌内效贴对前交叉韧带重建后患者影响的随机对照试验,检索时限均从各数据库建库至2022-12-06,结局指标包括股四头肌力量、腘绳肌力量、膝关节肿胀、膝关节活动度、Lysholm膝关节功能评分、目测类比评分6个连续型变量。运用EndNote X9.1筛选文献,采用Cochrane风险偏倚评估工具和Jadad量表评估纳入文献质量,采用RevMan 5.3软件进行Meta分析。结果:①共纳入6项随机对照试验,包括252例前交叉韧带重建后患者,其中对照组126例,肌内效贴组126例;②Meta分析结果显示,与对照组相比,肌内效贴组患者腘绳肌力量显著增加[SMD=0.68,95%CI(0.12,1.23),P=0.02]、目测类比评分显著降低[MD=-0.56,95%CI(-1.04,-0.08),P=0.02],两组患者间股四头肌力量、膝关节肿胀、膝关节活动度及Lysholm膝关节功能评分比较差异均无显著性意义(P>0.05)。结论:当前证据显示,肌内效贴可能有助于提升前交叉韧带重建后患者腘绳肌力量、减轻患者疼痛,然而并不能显著改善患者股四头肌力量、膝关节肿胀、膝关节活动度和功能评分。

基于人工鱼群算法的篮球跳投轨迹实时跟踪

篮球运动轨迹跟踪方法由于轨迹特征提取效果差,导致跟踪误差高,提出一种基于人工鱼群算法的篮球跳投轨迹实时跟踪方法。提取三维坐标系下图像中篮球边缘轮廓信息,通过滤波函数消除篮球跳投图像噪声,基于人工鱼群算法提取图像中篮球跳投轨迹特征,寻找篮球运动轨迹的最优解集,改进篮球实时跟踪匹配路径,形成轨迹跟踪函数。实验结果可知,该方法的平均轨迹跟踪误差为18.28mm,与常规方法相比降低了6.22mm以上。因此,该跟踪方法的篮球轨迹跟踪精度更高,并且实时跟踪轨迹与真实轨迹更吻合。

基于人工智能技术的机器人运动控制系统设计

设计一种基于人工智能技术的机器人运动控制系统,确保机器人更好地理解人类的意图,并提供更加人性化的服务。该系统通过运动数据采集与传输组件连接机器人的轴电机,采集机器人当前运动数据后,将其传输到控制器组件内,控制器组件依托X86架构工控机,使用PIC总线将采集到的机器人当前运动数据发送到基于人工智能技术的机器人运动路径规划模块内。该模块运用人工智能技术中的A*算法获取机器人轨迹路径规划结果后,依据该路径规划结果,将人工智能技术中的神经网络和模糊B样条基函数相结合,建立模糊B样条基函数神经网络控制器。该控制器输出机器人运动控制指令,并发送给伺服驱动器组件,伺服驱动器负责驱动机器人轴电机,控制机器人运动。实验结果表明:所设计系统具备较强的机器人路径规划能力,可在复杂路径情况下实现机器人运动控制,且控制精度和控制阶跃响应能力均较强。

MOTOmed智能运动反馈训练联合精细化康复训练对脑梗死后偏瘫患者的影响

目的 观察MOTOmed智能运动反馈训练联合精细化康复训练对脑梗死后偏瘫患者神经功能、平衡功能、肢体运动功能和生活质量的影响。方法 选择2022年1-10月在南通市第三人民医院康复中心住院治疗的148例脑梗死后偏瘫患者,采用随机数字表法分为对照组和观察组,每组74例。对照组在常规治疗基础上接受精细化康复训练。根据脑梗死患者(卧床患者、可坐立患者、借助辅具可站立患者和无辅具可挺直站立患者)肢体运动功能障碍程度给予相应的运动康复训练(如肢体关节训练、身体转移训练、平衡训练和步行训练等),5 d/周,持续治疗12周。观察组在对照组基础上联合MOTOmed智能运动反馈训练(被动运动模式、有助力运动模式和主动训练模式的上肢/下肢运动康复训练),1次/d,45 min/次,5 d/周,持续治疗12周。分别于治疗前后采用美国国立卫生研究院脑卒中量表(NIHSS)评分评估患者神经功能缺损情况;采用Berg平衡量表(BBS)评分评估患者平衡功能;采用Fugl-Meyer运动功能评定量表(FMA)评分评估患者肢体运动功能;采用改良Barthel指数量表(MBI)评分评估患者日常生活活动能力;采用世界卫生组织生活质量测定量表简表(WHOQOL-BREF)评分评估患者生活质量;比较患者大脑中动脉(MCA)、大脑前动脉(ACA)血流速度变化和血清神经生长因子(NGF)、脑源性神经营养因子(BDNF)水平。结果 与治疗前比较,2组治疗后NIHSS评分均明显降低,上肢/下肢FMA评分、BBS评分、MBI评分、WHOQOL-BREF评分、MAC和ACA血流速度、血清NGF和BDNF水平均明显升高,差异均具有统计学意义(P<0.05)。与对照组比较,观察组治疗后NIHSS评分明显降低,上肢/下肢FMA评分、BBS评分、MBI评分、WHOQOL-BREF评分、MAC和ACA血流速度、血清NGF和BDNF水平均明显升高,差异均具有统计学意义(P<0.05)。结论MOTOmed智能运动反馈训练联合精细化康复训练可改善脑梗死后偏瘫患者神经功能、平衡功能、肢体运动功能和生活质量,值得临床推广。

早期康复治疗对手部瘢痕挛缩患者术后手功能的影响

目的 探讨早期康复治疗对手部瘢痕挛缩患者术后手功能影响。方法 采用回顾性非随机对照的研究方法,选取2019年9月至2022年3月于郑州大学第一附属医院烧伤与修复重建外科收治的60例手部瘢痕挛缩伴功能障碍患者的临床资料,瘢痕挛缩时间3~12个月,其中男32例,女28例,年龄6~30岁。根据患者是否在术后1个月内进行手部康复功能锻炼分为早期康复组(≤1个月)和晚期康复组(>1个月)。所有患者接受相同的康复内容,包括瘢痕皮肤护理,外用防疤药物,瘢痕按摩,主、被动关节活动,压力治疗,支具佩戴等。嘱患者及家属分别于术后3、6个月来院复查。对比两组患者基本资料和切口愈合时间,采用温哥华瘢痕量表(VSS)评估患者术前及术后3、6个月手部瘢痕增生情况;采用Jebsen手功能测试评估患者治疗前及术后3、6个月的手功能变化;采用总主动活动度法评定手指关节活动度,并计算优良比;记录两组患者术后不良反应发生情况。结果 术前两组手部瘢痕评分、完成Jebsen手功能测试所需时间比较,差异无统计学意义(P>0.05),术后3、6个月,早期康复组手部瘢痕评分均低于晚期康复组,完成Jebsen手功能测试所需时间均短于晚期康复组(P<0.05)。术前早期康复组和晚期康复组手关节活动度优良比分别为4/30、5/30,术后3个月优良比分别为28/30、22/30;术后6个月优良比分别为29/30、23/30,术后3、6个月,早期康复组手关节活动度优良比高于晚期康复组(P<0.05);两组治疗期间均未出现皮片坏死、感染、水疱等不良反应。结论 早期康复治疗能改善手瘢痕增生情况,增加相关受累关节活动范围,能较好恢复手功能,从而提高患者的生活质量。

基于轮廓误差灵敏度函数的增益匹配研究

现有数控系统和伺服驱动系统开放性有限,实时轮廓误差控制策略难以实现,为避免加工设备二次开发,研究了精密加工轮廓误差的离线补偿方法,本文提出了一种以减少轮廓误差为目的的跟踪误差匹配方法。首先在构建各进给系统的机电混合控制模型的基础上,推导轮廓误差关于参考轨迹的灵敏度函数;然后以轮廓误差灵敏度函数为理论依据,针对数控加工过程中常用的G01直线和G02/G03圆弧指令,分析伺服参数在不同运动学参数下对加工轨迹的影响;最后通过调整各伺服轴的控制参数,匹配动态误差系数,提高轮廓精度。此方法可在不增加控制系统复杂性的同时减小各轴动态特性导致的误差,对提高多轴联动加工轮廓精度具有参考价值。

麦肯基运动疗法联合颈椎关节松动术与耳穴压豆治疗颈型颈椎病临床效果

目的:探讨麦肯基运动疗法联合颈椎关节松动术与耳穴压豆治疗颈型颈椎病临床效果。方法:将广州医科大学附属第六人民医院2021年1月—2022年8月门诊及住院部接收的颈型颈椎病患者160例作为研究对象,采用随机数字表法将其分为对照组与研究组,每组80例。对照组采用麦肯基运动疗法,研究组采用麦肯基运动疗法联合颈椎关节松动术与耳穴压豆治疗,两组均持续治疗3个月。采用颈椎功能障碍指数(NDI)、疼痛灾难化量表(PCS)评价颈功能、疼痛程度。比较两组颈椎活动范围、凝视稳定性(GS)测试阳性率、眼动测试(EMT)阳性率。结果:治疗后,研究组NDI评分低于对照组,差异有统计学意义(P<0.05)。治疗后,研究组PCS评分的疼痛反复思虑、疼痛无助感、疼痛夸大维度得分及总分均低于对照组,差异均有统计学意义(P<0.05)。治疗后,研究组颈椎前屈、后伸、左右侧屈、左右旋转活动范围均高于对照组,差异均有统计学意义(P<0.05)。治疗后,研究组GS阳性率、EMT阳性率均低于对照组,差异均有统计学意义(P<0.05)。结论:麦肯基运动疗法联合颈椎关节松动术与耳穴压豆治疗颈型颈椎病,可有效恢复颈椎功能,减轻疼痛,增加颈椎活动范围,改善颈椎神经的协调性和稳定性。

CTAR联合吞咽低频电刺激治疗CS后DAS患者的效果

目的探讨下颏抗阻力训练(chin tuck against resistance,CTAR)联合吞咽低频电刺激治疗脑卒中(cerebral stroke,CS)后吞咽障碍(dysphagia after actue stroke,DAS)患者的疗效。方法采用配对病例对照研究法选取虞城县人民医院康复科2021年1月至2023年9月收治的84例CS后DAS患者进行回顾性研究,按治疗方案不同分为参照组(n=42)、研究组(n=42)。其中采用吞咽低频电刺激治疗的患者设为参照组,采用CTAR联合吞咽低频电刺激治疗的患者设为研究组。比较两组治疗前、治疗4周后吞咽功能障碍分级情况、标准吞咽功能评定量表(SSA)评分、功能性经口舌摄食量表(FOIS)评分、舌骨喉活动度、表面肌电图、吞咽障碍特异性生命质量量表(SWAL-QOL)评分。结果研究组治疗4周后吞咽功能障碍改善情况优于参照组(P<0.05);研究组治疗4周后SSA评分为(24.18±2.12)分,低于参照组(28.79±3.77)分,FOIS评分为(5.68±0.45)分,高于参照组(4.63±0.51)分(P<0.05);研究组治疗4周后舌骨前移、上移活动度分别为(11.47±2.55)mm、(17.38±4.59)mm,高于参照组(8.25±1.06)mm、(14.03±4.56)mm(P<0.05);研究组治疗4周后最大波幅为(725.38±55.02)V,高于参照组(605.98±49.65)V,吞咽时程为(1.11±0.15)s,短于参照组(1.33±0.21)s(P<0.05);研究组治疗4周后SWAL-QOL评分为(125.32±15.32)分,高于参照组(102.54±14.25)分(P<0.05)。结论CTAR联合吞咽低频电刺激治疗CS后DAS患者可有效提高舌骨喉活动度,改善吞咽、摄食功能,促进生活质量提升。

基于RBF神经网络补偿的ROV运动控制算法

针对作业型遥控水下航行器(ROV)在模型参数不确定和外部环境干扰下的运动控制问题,提出了一种基于径向基函数(RBF)神经网络的自适应双环滑模控制策略。首先,对于ROV外环位置控制采用改进趋近律的积分滑模控制方法,对于ROV内环速度控制采用指数趋近律的积分滑模控制方法;其次,为进一步改善滑模控制的抖振问题,引入双曲正切函数作为滑模切换项;然后,利用RBF神经网络控制技术对ROV模型的不确定参数和外部扰动进行估计与补偿;最后,利用李雅普诺夫稳定性理论证明了整个闭环系统的稳定性,并对作业型ROV的运动控制进行了数值仿真。仿真结果验证了所设计的控制器可以实现ROV航行的精确控制,并能够有效抑制模型不确定参数和外部扰动对ROV运动的影响。

基于黑潮流场背景的水下滑翔机运动控制仿真

近年来,水下滑翔机已广泛应用于各种海洋观测领域,但在对黑潮等强流进行观测时,其运动轨迹往往会受到严重影响,因此文中针对黑潮流域内水下滑翔机运动轨迹控制问题进行研究。首先,以“海燕II”为研究对象,根据动量和动量矩定理建立了其考虑黑潮的动力学模型;然后将HYCOM黑潮区域数据作为干扰,其特点是黑潮流速的大小与方向都会随着位置的变化而改变,并利用Simulink对强流影响下的“海燕II”运动轨迹进行了仿真;最后,将径向基函数(RBF)神经网络与常规比例-积分-微分(PID)控制器相结合,对“海燕II”的偏航与纵倾运动进行控制。仿真结果表明RBF-PID控制器可以在一定程度上提高“海燕II”在黑潮区域运动的跟踪精度,增强抵抗黑潮干扰的能力,可为在强流影响下的水下滑翔机轨迹控制提供参考。