基于OpenMP并行技术的多核环境下轮对图像处理方法研究

基于光电图像的轮对磨耗在线检测过程中,轮对图像处理的速度对在线检测的实时性有重要影响。针对轮对图像的处理速度不能够满足轮对高速在线检测要求的问题,利用多核处理器的计算优势,对基于Open MP并行技术的轮对图像处理方法进行了研究。通过分析轮对图像的特点,对不同类型的轮对图像采用了不同的分割方法,减小了轮对图像分割环节对后期处理的影响;提出了采用多图并行处理的编程模式,设计了并行优化方案,利用Open MP并行技术对轮对图像的处理进行了并行优化;并将Open MP四线程与单线程对轮对图像的处理结果进行了对比分析,验证了轮对图像处理加速效果。研究结果表明,多核环境下,轮对图像处理通过Open MP并行优化,获得了高于2倍的加速比,可满足车辆轮对检测速度达到80 km/h的在线检测要求。     

新型串并联机器人的仿真设计

设计出了一种具有6自由度的新型串并联机器人,介绍了该机器人的结构和工作原理,并对该机器人的自由度进行了计算,之后对机器人进行了运动学分析,给出了其末端执行器的运动方程,最后对其进行了计算机仿真并对仿真结果进行了分析.     

砌块成型机振动模态与谐响应分析及设计改进

对某砌块成型机进行了有限元建模,介绍了建模方法,通过砌块成型机的模态试验结果,对其进行了修正.分析了各阶模态振型.修正结果表明,砌块成型机模型能够反映其真实的动态特性,同时对振动台进行了谐响应分析,得出了砌块成型机振动台的理论振幅值,并对砌块质量进行了评价.最后根据现场测试对砌块成型机进行了结构改进.     

数控车削加工的对刀方法及技巧

以FANUC—Oi系统为例,分析了数控车削加工时的对刀原理,介绍了车削加工时的对刀方法,并结合实际应用提出了一些对刀技巧,对提高对刀的准确性和对刀效率有指导意义。     

磨削因素对陶瓷轴承外圈内表面粗糙度的影响

主要介绍了磨削因素对陶瓷轴承外圈的内表面粗糙度的影响,通过单一方法和正交试验法对陶瓷轴承外圈进行了加工,并对试验数据进行了分析,得出了磨削因素对表面粗糙度影响的规律,完善了陶瓷轴承的磨削加工理论,对陶瓷轴承的磨削加工具有重要意义.     

树脂基复合材料发动机机架结构研究

采用树脂基复合材料,对发动机执架的结构进行了设计,对结构进行了材料工艺及静强度试验研究.在设计分析的基础上,对纤维和树脂基体的筛选、优化进行了研究,对复合材料的基本力学性能和疲劳老化性能进行了研究.最后对大部件复合材料固化成型的工艺参数进行了优化,开展了机架结构连接方式和相关接头加工技术可行性研究.本文对树脂基复合材料在航天主承力结构上的应用进行了初步的探索和研究.     

新一代数控车床样机切削力测试试验研究

设计了切削力测试试验,对数控车床切削45钢切削用量对切削力的影响进行了试验研究,重点分析了切削用量对主切削力的影响规律。设计了切削用量对切削力影响单因素试验和正交试验,并对试验结果进行了分析,根据正交试验结果对主切削力经验公式进行了拟合,结果表明:切深和进给速度对切削力的影响显著,切削速度对切削力的影响不显著,该经验公式具有较高的预测精度。     

往复泵曲轴强度及疲劳分析

根据往复泵曲轴受力分析的结果,利用ANSYS对曲轴的静强度进行了计算,对疲劳强度进行了分析,比较了两种材料的力学性能,对曲轴材料进行了优化选择。     

谈以信息化带动工业化的认识与措施

根据对信息化的分析,论述了信息化带动工业化的必然性,分析了信息技术是生产力的标志,讨论了国内外信息化形势,进而提出了对信息化的客观认识和应采取的措施,强调了领导干部对信息化的态度,提出了人才培养的方式.     

浅谈机械加工圆锥面的对刀方法

本文介绍了机械加工圆锥面的几种对刀方法,并给出了各种对刀方法的名称,比较了各种对刀方法的优缺点和使用范围,并对作者提出的对刀装置法作了较详细的介绍。     

Analyzing the Efficiency of the Forward Radiation Shielding for the CMS Detector at the LHC

The forward radiation shielding of the CMS detector is developed for the LHC by the Institute for High-Energy Physics. The efficiency of this shielding is analyzed on the basis of the results of numerical simulation. The computed particle-flux densities are compared to those of the ideal model of the shielding. The secondary-radiation field near the detector is investigated with different configurations of the shielding. Measures for reinforcing the shielding of the detector's experimental zone are proposed. The possibilities of improving the shielding structure and the composition of its materials are discussed.     

Characteristics of the inlet with the pressure perturbation in the ramjet engine

Flows in a ramjet inlet is simulated for the study of the rocket-ramjet transition. The flow is unsteady, two-dimensional axisymmetric, compressible and turbulent. Double time marching method is used for the unsteady calculation and HLLC method is used as a higher order MUSCL method. As for turbulent calculation, k — ω SST model is used for more accurate viscous calculations. Sinusoidal pressure perturbation is given at the exit and the flow fields at the inlet is studied. The cruise condition as well as the ground test condition are considered. The pressure level for the ground test condition is relatively low and the effect of the pressure perturbation at the combustion chamber is small. The normal shock at the cruise condition is very sensitive to the pressure perturbation and can be easily detached from the cowl when the exit pressure is relatively high. The sudden decrease in the mass flux is observed when the inlet flow becomes subcriticai, which can make the inlet incapable. The amplitude of travelling pressure waves becomes larger as the downstream pressure increases, and the wavelength becomes shorter as Mach number increases. The phase difference of the travelling perturbed pressure wave in space is 180 degree.     

The Influence of the vane on the lubrication characteristics between the vane and the rolling piston of a rotary compressor

The rolling piston type rotary compressor has been widely used for refrigeration and air-conditioning systems due to its compactness and high-speed operation. The present analysis is part of a research program directed toward maximizing the advantages of refrigerant compressors. The study of lubrication characteristics in the critical sliding component is essential for the design of refrigerant compressors. Therefore, theoretical investigation of the lubrication characteristics of a rotary compressor being used for refrigeration and air-conditioning systems was investigated. The Newton-Raphson method was used for a partial elastohydrodynamic lubrication analysis between the vane and the rolling piston of a rotary compressor. The results demonstrated that the vane thickness and the center line position of the vane significantly influenced the friction force and the energy loss between the vane and the rolling piston.     

Relating Friction on the Human Skin to the Hydration and Temperature of the Skin

The human skin is constantly in interaction with materials and products. Therefore, skin friction is relevant to all people. In the literature, the frictional properties of the skin have been linked to a large variety of variables, like age, gender and hydration. The present study compares the data of 450 skin friction measurements with the skin hydration and skin temperature on four locations on the body, measured with four materials: stainless steel (SST), aluminum (Al), PE and PTFE. The median skin temperature was 32.1 °C and the median skin hydration was 25.5 AU, as measured with a Corneometer. The median coefficient of friction was 0.52 for the static coefficient of friction and 0.36 for the dynamic coefficient of friction. There was a linear relationship between those two types of coefficient of friction. The coefficient of friction was highest for SST and lowest for PTFE. The frictional properties depend on the skin hydration and skin temperature. Gender differences were found for both skin hydration and coefficient of friction. Most of the variation in the coefficients of friction could be explained by the differences in hydration.     

模糊综合评价法在油井管杆偏磨分析中的应用

综合分析了油井管杆偏磨产生的原因,建立了管杆偏磨的评价指标体系,通过模糊综合评价法,对管杆偏磨的原因进行了评价,并用具体事例给予说明,具有较强的实用性。     

用移动式测力仪调试汽车衡

本文指出目前流行的电子汽车衡调试方法存在的弊端,提出了用移动式测力仪新的调试技术。结合规范安装工艺能达到既高效节能大降费用,又能保持相对长期稳定精度的效果。     

Development of the Readout and Data-Acquisition System for the RICH Detector of the CBM Experiment

A 64-channel readout and data-acquisition module is described in detail. It consists of an H12700 multianode photomultiplier tube, four PADIWA preamplifier boards, and a TRB v3 card that perform the functions of a time-to-digital converter and a data concentrator. The software modules that are necessary for operation of the prototype are described. The inter-channel delays are calibrated. The drift of individual delays does not exceed 0.5 ns for the entire measurement time. The spectra of the “time over threshold” (ToT) are investigated. The influence of periodic noise pickups and the need to improve circuit designs are revealed. The timing properties of the wavelength shifter and its effect on the detection efficiency for Cherenkov rings are investigated. The most intense component is characterized by a decay time of 1.1 ns and there are components with characteristic times of 3.8 and 45 ns. The influence of single-electron spectrum features on the detection efficiency for photoelectrons and the probability of false hits are determined. The total time resolution of 131 channels is 1.1 ns (FWHM). The results make it possible to use the investigated system of readout and data acquisition in the CBM experiment. Nevertheless, the elimination of the revealed shortcomings will provide the efficiency margin and improve the reliability of the system during long-term operation.     

A model for the prediction of the forces at the glenohumeral joint

The design, validation, and application of a three-dimensional musculoskeletal model of the upper limb is presented here, for the study of joint, muscle, and ligament forces during selected tasks of daily living. Much of the model was constructed using data gathered from real cadavers, including the extensive 'visible human' data set, together with information gathered from published post mortem studies on cadavers. Validation was carried out through comparison of model outcomes with available data in the literature. The model was then used to examine the glenohumeral joint loading during ten previously selected activities of daily living. The predicted glenohumeral joint contact forces during everyday activities were found to range from 23 to 75 per cent body weight. A linear regression method for estimating the joint load from externally measured kinetics was developed, giving a 95 per cent confidence interval in predicted joint forces of 8 per cent body weight. The model presented here, namely the Newcastle shoulder model, provides a basis for future studies into biomechanical problems relating to the understanding of musculoskeletal pathology and implant design and performance.     

Testing the electronic system for the γ-quantum detector of the SVD-2 setup

Firmware for checking the electronic equipment for recording signals of the hodoscope γ-quantum detector is described. The detector has 1344 channels for measuring charges of nanosecond pulses arriving from outputs of photomultiplier tubes. The testing system is intended to test the electronics at each level of its hierarchical structure and also to perform the initial check of the γ-quantum detector itself.     

基于螺旋理论对少自由度并联机器人约束链的研究

螺旋理论是分析少自由度机构运动学的有力工具。本文基于螺旋理论对少自由度并联机器人的机构构型中的约束问题作了分析,并对约束链的自由度作了计算,为并联机构的特殊型位分析、运动分析、受力分析提供了有力证据,并进一步丰富了螺旋理论的应用。