Phase-Based Optical Flow Method with Optimized Parameter Settings for Enhancing Displacement Measurement Adaptability

To enhance the applicability and measurement accuracy of phase-based optical flow method using complex steerable pyramids in structural displacement measurement engineering applications, an improved method of optimizing parameter settings is proposed. The optimized parameters include the best measurement points of the Region of Interest (ROI) and the levels of pyramid filters. Additionally, to address the issue of updating reference frames in practical applications due to the difficulty in estimating the maximum effective measurement value, a mechanism for dynamically updating reference frames is introduced. Experimental results demonstrate that compared to representative image gradient-based displacement measurement methods, the proposed method exhibits higher measurement accuracy in engineering applications. This provides reliable data support for structural damage identification research based on vibration signals and is expected to broaden the engineering application prospects for structural health monitoring.

Automatic Optimization of Chirp Setting Parameters in Medical Ultrasound Contrast Imaging

Medical ultrasound contrast imaging is a powerful modality undergoing successive developments in the last decade to date Lately, pulse inversion has been used in both ultrasound tissue harmonic and contrast imaging. However, there was a tradeoff between resolution and penetration. Chirp excitations partially solved the tradeoff, but the chirp setting parameters were not optimized. The present work proposes for the first time combining chirp inversion with ultrasound contrast imaging, with the motivation to improve the contrast, by automatically optimizing the setting parameters of chirp excitation, it is thus an optimal command problem. Linear chirps, 5 μm diameter microbubbles and gradient ascent algorithm were simulated to optimize the chirp setting parameters. Simulations exhibited a gain of 5 dB by automatic optimization of chirp inversion relative to pulse inversion. The automatic optimization process was quite fast. Combining chirp inversion with ultrasound contrast imaging led to a maximum backscattered power permitting high contrast outcomes and optimum parameters.

Effect of Heat-Setting on Structural Parameters and Mechanical Properties of PP Monofilament Hernia Patch

General surgery hernia is a common and frequently- occurring disease in the world. In the tension-free hernia repair surgery, polypropylene （PP） patch has been confirmed as the most popular surgical implants. In this study, domestic medical PP monofilament was selected as raw material whose diameter was 0.15 mm, and the patch was knitted in the warp knitting machine of 12E gauge with one bar. Using the method of orthogonal experiment with three factors and three levels, the best heat-setting process of PP mesh was determined at the temperature of 130 ~C with 10 min under tension-free conditions. The relationship between heat-setting tension and performance of the patch was discussed. Patches with different porosity were prepared, and then structural parameters including density, thickness, porosity, and mechanical properties including tensile breaking strength, bursting strength, tearing strength, flexural rigidity and suture pulling out strength were tested and compared. The experimental results show that： the smaller of the patch＇s density, the higher of the porosity; other properties including density, thickness, bending stiffness, tensile breaking strength, bursting strength, tear strength, and suture pulling out strength reduce in varying degrees. This different degree of reduction is worth summarizing.

Effect of parameter setting and spectral normalization approach on study of matrix effect by laser induced breakdown spectroscopy of Ag–Zn binary composites

The complex nature of laser-material interaction causes non-stoichiometric ablation of alloy samples.This is attributed to matrix effect, which reduces analyzing capability. To address this issue, the analytical performance of three different normalization methods, namely normalization with background, internal normalization and three point smoothing techniques at different parameter settings is studied for quantification of Ag and Zn by Laser induced breakdown spectroscopy(LIBS).The LIBS spectra of five known concentration of silver zinc binary composites have been investigated at various laser irradiances(LIs). Calibration curves for both Ag(I) line(4d^(10)5s^2S_(1/2)→4d^(10)5p^2P_(1/2) at 338.28 nm) and Zn(I) line(4s5s^3S_1→4s4p^3P_2 at 481.053 nm) have been determined at LI of 5.86?×?10^(10)W cm^(-2). Slopes of these calibration curves provide the valuation of matrix effect in the Ag–Zn composites. With careful sample preparation and normalization after smoothing at optimum parameter setting(OPS), the minimization of sample matrix effect has been successfully achieved. A good linearity has been obtained in Ag and Zn calibration curve at OPS when normalized the whole area of spectrum after smoothing and the obtained coefficients of determination values were R^2?=?0.995 and 0.998 closer to 1. The results of matrix effect have been further verified by analysis of plasma parameters. Both plasma parameters showed no change with varying concentration at OPS. However, at high concentration of Ag, the observed significant changes in both plasma parameters at common parameter setting PS-1 and PS-2 were the gesture of matrix effect. In our case, the better analytical results were obtained at smoothing function with optimized parameter setting that indicates it is more efficient than normalization with background and internal normalization method.

Application of MPSO technique to find optimal location and parameter setting of TCSC

A new mothod was presented to find the optimal location and parameter setting of Thyristor Controlled Series Compensator (TCSC) to maxmize the transfer capability.Firstly the sensitivity of the transfer capability with respect was described to the line's reactance was described to find the more sensitive lines for installing TCSC,however,the line which has the most sesitivity value is always not the best line for installing TCSC.For solving this problem,the more sensitive m lines were selected as the alternative line group of installing TCSC,and then modified particle swarm optimization (MPSO) was used to find out the optimal location and the optimal parameter settings of TCSC.Particle swarm optimization (PSO) algorithm can results premature convergence.For solving this problem,population entropy and cellular automata were introduced to it.Simulation results of IEEE 30-bus system proved the effectiveness of the method and its application values.

Effects of transmitter-related parameter settings on ranging accuracy for IR-UWB systems

For impulse radio ultra-wideband (IR-UWB) ranging systems,effects of the settings of transmitter-related parameters, which include the pulse shape, the bandwidth and the pulse repetition interval (PRI), on ranging accuracy were studied through theoretical analysis and simulations. Both the match-filtering based coherent TOA estimation algorithm and the energy-detection based non-coherent algorithm were used during simulations. Results show that the pulse shape has the least effect on the ranging accuracy. Increasing the pulse bandwidth can improve the ranging performance, but the performance is hardly improved any more when the bandwidth is increased beyond a certain level. PRI should be set long enough to guarantee the accurate ranging, because when PRI is shorter than the maximum excess delay of the channel, the ranging accuracy will be deteriorated by inter-pulse interference.

Calculation Model of Equivalent Strength for Induced Crack Based on Double-K Fracture Theory and Its Optimizing Setting in RCC Arch Dam

By means of fracture testing on roller-compacted concrete （RCC） three-point bending beams with two different specimen sizes, the P-CMOD complete curve for RCC was gained. Furthermore, by applying double-K fracture theory, KiniⅠC,KunⅠC, as well as the critical effective crack length and the critical crack tip opening displacement, were evaluated. Based on the double-K fracture parameters above, the calculation model of equivalent strength for induced crack was established, thus the calculation method on its initiation, stable propagation and unstable fracture was ascertained. Moreover, the finite element simulation analysis of stress field in ShaPai arch dam and the on-site observational splaying points of induced crack at different altitudes validated the reliability of the model. Finally, crack inducer′s optimal setting in RCC arch dam was studied. It improves the design level of induced crack in RCC arch dam and satisfies the necessity of engineering practice.

Sensitivity analysis for parameters of a monitoring system for steep slopes of open-pit mines

Monitoring the stability of steep slopes of open-pit mines is a major issue relating to production safety in mines.In order to determine the technical parameters of a new type of supervising system applied in monitoring steep slopes of open-pit mines,the MSARMA method was used to establish analytical models for the monitoring system,given various parameter settings based on the description of mechanical monitoring principles.We used this sensitivity analysis to conclude that the setting of the most sensitive location of a mechanical monitoring system should be within a range of 1/5～1/2 of the lower part in a vertical direction of steep slopes,with a rational and feasible range of the dip angle setting between 0°～20°.Given the analytical results of our on-site experiments,we have shown that the parameters determined reflect the stability of steep slopes accurately and effectively.These conclusions provide a basis for the application of a new type of steep slope stability monitoring technology in open-pit mines.

An approach to optimize the settings of actuated signals

Traffic-actuated signal employs relatively complex control logic to regulate traffic flow. Introduction of control variables into the traffic-actuated system contributes to system operational flexibility and complexity, and also complicates the system with uncertainties. The paper proposes two tentative methods to optimize the actuated signal parameters： basic requirements of controller parameters and analytical model, and macroscopic computer simulation. It is concluded that when the actuated signal operates within the volume/capacity range of 0.4 to 0.6, it will create the most significant benefits; the research suggests that minimum green time in the main street shall be set long enough to meet the required demand, preferably at the 60% of the main street capacity. In order to ensure less control delay in a semi-actuated intersection, relatively small values of vehicle extension （e.g., 2.5 s） and maximum green time are recommended to be assigned to the less important street.

Analysis on a Set of 12-parameter Rectangular Plate Element with High Accuracy

It is proved that the so-called a set of 12-parameter rectangular plate elements with high accuracy constructed by using double set parameter method and undetermined method are, in fact, the same one; the real shape function space is nothing but the Adini＇s element＇s, which has nothing to do with the other high degree terms and leads to a new method for constructing the high accuracy plate elements. This fact has never been seen for other conventional and unconventional, conforming and nonconforming rectangular plate elements, such as Quasi-conforming elements, generalized conforming elements and other double set parameter finite elements. Moreover, such kind of rectangular elements can not be constructed by the conventional finite element methods.

Reconstruction of protoliths of metamorphic rocks and tectonic setting of Wolegen Group

Parametamorphic rocks from Arong County in southeastern Inner Mongolia- Daxinganling district are regarded as Proterozoic in age, belonging to the Wolegen Group and composed of volcanoclastic and sand- stone in origin, and have been disputed in tectonic setting. Because of the stability in metamorphism, the rare earth elements indicate the features of their protoliths. The authors integrated the petrologic methods with the geochemical parameters which include ЕREE, ЕLREE/NHREE, δCe, δEu, La/Yb, Sm/Nd, Th/Sc and the standard values of chondrite. The results show that the protoliths of Wolengen Group may be a group of volcanoclastic and continental margin clastic rocks, and their tectonic setting is the continent island arc.

纳布啡不同镇痛泵参数用于剖宫产术后镇痛的比较

目的比较三种不同参数纳布啡患者自控静脉镇痛(PCIA)用于剖宫产术后镇痛的效果。方法选择剖宫产术后的产妇179例,年龄18~45岁,BMI 20~35 kg/m 2,ASAⅠ或Ⅱ级,术后均给予PCIA(纳布啡2 mg/kg+托烷司琼8 mg/100 ml,间隔时间15 min,极限量10 ml/h)。将产妇随机分成三组:对照组(C组,背景量2 ml/h,单次按压2 ml,n=60)、低背景量组(L组,背景量1 ml/h,单次按压3 ml,n=62)和无背景量组(N组,背景量0 ml/h,单次按压4 ml,n=57)。记录术后2、6、12、24、48 h静息和活动时VAS疼痛评分、纳布啡消耗量。记录术后48 h内PCIA按压情况、术后首次肛门排气时间、术后住院时间、Ramsay镇静评分和术后恶心呕吐、头晕、感染等不良反应的发生情况。结果与C组比较,N组术后6、12 h静息时VAS疼痛评分明显升高(P<0.05),L组和N组术后24、48 h纳布啡消耗量明显减少,术后首次肛门排气时间明显缩短,头晕发生率明显降低(P<0.05),N组术后住院时间明显缩短(P<0.05)。与L组比较,N组术后12 h静息和活动时VAS疼痛评分明显升高,术后48 h纳布啡消耗量明显减少,总按压次数和有效按压次数明显增加,术后首次肛门排气时间明显缩短(P<0.05)。三组Ramsay镇静评分和术后恶心呕吐、感染发生率差异无统计学意义。结论低背景量(1 ml/h)纳布啡PCIA可在充分镇痛的同时,减少阿片类药物用量,降低相关不良反应发生率,缩短术后首次肛门排气时间,可作为纳布啡PCIA用于剖宫产术后镇痛参数设置的优先选择。

改进势场蚁群算法优化路径自动规划

针对势场与蚁群联合的自主路径规划存在局部最优解、初始路径选择随机导致效率不高及环境适应性差等问题,提出了基于自适应域和参数自适应设置的改进算法。算法首先基于自适应域改进势场目标不可达问题,并过滤震荡点以平滑路径;其次,通过状态转移函数和信息素更新等相关参数的自适应设置,提高算法在收敛效率和搜索能力上的平衡性,进而提高对障碍环境的适应性。实验结果表明,所提算法能够有效避免局部最优、目标不可达和复杂环境的适应性问题,在路径长度和效率上优于实验采用的已有算法,从而验证了算法的有效性。

基于改进型SM-ADRC的PMSM控制策略研究

在永磁同步电机(PMSM)控制中,传统的滑模自抗扰控制(SM-ADRC)能够减小外部负载变化和参数变化导致控制系统性能下降所带来的影响,但是还存在控制器参数太多,整定过于复杂化的问题,故提出一种改进型SM-ADRC方法。设计了一种新型变指数趋近律及新型控制函数将其引入扩展状态观测器(ESO)和非线性状态误差反馈控制律(NLSEF),得到新型滑模状态观测器(SM-ESO)和新型滑模状态误差反馈控制律(SM-NLSEF),减少了SM-ESO和SM-NLSEF待整定参数个数,简化了SM-ADRC参数整定。建立Simulink仿真模型和Links-RT半实物仿真实验平台,仿真和实验结果均表明:与传统SM-ADRC相比,改进型SM-ADRC在简化参数整定的同时提高了系统的响应速度和系统的抗扰性能,减小了电流脉动。

光学感应式下颌运动轨迹描记所获参数准确性及可重复性的体外研究

目的通过体外实验,测量并比较不同设定角度、不同操作路径下前伸髁导斜度及切导斜度的差别,评价光学感应式下颌运动轨迹描记的参数结果准确性及可重复性。方法根据实际招募受试者口内光学扫描及上下颌牙列坐标数据文件,设计制作个性化测量模型及固定装置,3D打印加工并安装于全可调咬合架上。调节咬合架双侧前伸髁导斜度及前伸切导斜度,设10°至60°梯度变化共12组,使用咬合架设定参数模块完成下颌运动轨迹描记,并读取测量参数进行统计学分析。结果除前伸髁导斜度40°与60°组及前伸切导斜度10°组外,其余各组测量值与设定值均存在统计学差异,标准差范围0.300°~2.994°;不同铰链轴测定的操作路径所获得前伸髁导斜度数值不存在统计学差异。结论光学感应式下颌运动轨迹描记所获得的参数准确性及可重复性可满足临床应用需求,但其测量值仍与设定值存在一定差异。在保证测试装置稳定的前提下,针对同一对象进行多次不同测试时,是否进行重复轴定位对于测量结果不存在明显影响。

库尔勒香梨大疆T50无人机授粉参数优选与田间验证

为了提高库尔勒香梨无人机授粉作业的精确性,选用大疆T50无人机,采用三因素(作业速度、作业高度、667 m^(2)喷施量)三水平的正交试验,比较雾滴覆盖率、雾滴密度及雾滴沉积量的分布效果,筛选作业参数并进行了田间授粉效果的验证。结果表明:在环境风速不超过1.5 m/s的条件下,大疆T50无人机对纺锤形库尔勒香梨授粉的最佳作业参数为作业速度4 m/s、作业高度距离树顶4.5 m、667 m^(2)喷施量4L;田间授粉的花序坐果率为75.56%,花朵坐果率为32.87%。影响库尔勒香梨树冠上层雾滴效果的主要因素依次为667 m^(2)喷施量、作业高度、作业速度,影响树冠中层和下层雾滴效果的主要因素依次为667 m^(2)喷施量、作业速度、作业高度。

带式输送机托辊组振动噪声仿真分析及参数优化

带式输送机托辊组产生的振动噪声受多因素联合影响,为解决其振动噪声过大问题,文章提出一种基于有限元-边界元理论对托辊组振动噪声分析与优化的方法。首先,对托辊组进行模态分析与动力学仿真,探明托辊组的振动特性;然后,基于有限元-边界元复合声场仿真方法,作声场的谐响应分析计算托辊组的声场分布,并搭建实际测试平台验证声学仿真模型的可靠性;最后,结合输送能力与轻量化约束条件,得到托辊组结构参数与工作参数的最优解。结果表明,有限元-边界元法可有效模拟托辊组声场分布和变化规律,优化后托辊组噪声声压级较优化前减小约6.1dB,并且托辊组综合性能均有所改善,可对实际工程中的带式输送机优化设计起到有效的指导作用。

复杂光机系统综合性能评估方法

作为涉及光、机、电、控、热、气、液等多个领域的复杂光机系统,如何对其进行综合性能评估一直是难以解决的关键技术问题。针对该问题,通过分层分析并结合熵值、灰色和模糊评估等方法,提出了能够直观反映复杂光机系统的评估因子,即G因子。通过G因子,可直观地对复杂光机系统的综合性能进行评估,并可对比不同光机系统的综合性能;同时在评估过程中,也可对复杂光机系统的某个或几个关键参数进行对比分析。G因子提供了一种能够反映复杂光机系统综合性能的直观参数,为复杂光机系统的综合性能评估及相关系统研制提供了技术支撑。

基于气动肌肉驱动的关节自抗扰控制

为了解决气动人工肌肉驱动的下肢康复机器人轨迹跟踪中存在外界干扰和系统参数不确定的问题,提出了一种关节控制自抗扰算法。该方法在气动人工肌肉关节伺服控制系统数学模型基础上,通过三阶状态扩张观测器对系统状态及系统干扰进行估计,对干扰进行实时补偿,并基于分离性原理进行参数整定;利用气动人工肌肉试验平台对控制系统进行定角度条件下的阶跃信号跟踪控制、方波跟踪控制和正弦跟踪控制对比验证实验。实验结果表明:所设计的自抗扰控制器较比例-积分-微分(proportion integration differentiation,PID)控制器响应时间更快、控制误差更低,满足下肢康复机器人的应用控制要求。

面向造纸辊轴的数控车床编程参数优化研究

造纸辊轴质量本质上取决于数控车床加工程序,因此在车床数控化率日趋攀升的推动下,满足数控车床快速编程与高效加工的个性化需求值得探究。而由于数控车床缺乏非圆曲线插补功能,因此实际生产过程中椭圆与抛物线等典型非圆曲线编程需以宏程序加以实现。由此,基于造纸辊轴加工需求与椭圆曲线方位,针对性设置了数控车床编程参数,以计算与生成了数控车床宏程序。此数控车床宏程序不仅能提高造纸辊轴加工精确度与加工效率,还可优化加工工序,消除加工空行程,兼具可靠性与通用性。