一种新型高精度的中位面法储油罐罐容测算研究

提出了一种新的储油罐罐容计算方法,有较高的精确度和较低的计算复杂度,并用形象的图形给出了罐体变位前后罐容表,达到良好的仿真结果分析,能够很好的推广应用。     

基于FPGA的传感数据加速处理*

随着传感器网络技术的快速发展,实时处理海量的高速的传感数据为现有数据处理技术提出许多挑战。利用非对称性多核系统加速特殊操作是当前计算机体系结构发展的一种趋势,是解决物联网应用实时响应的有效途径。本文提出一种基于FPGA加速处理传感数据中位数计算的方法,包括计算模型、符合FPGA设计限制的实现过程,把FPGA连接到系统的其他部分的适当的融合策略,实验表明与通用CPU相比,本文提出的基于FPGAs的加速数据处理策略在功耗和并行传感数据流评价方面具有明显的优势,可以广泛地应用于物联网中前端轻量级数据预处理节点的设计与实现。     

基于模糊推理的方向中值椒盐滤波算法

针对灰度图像中的椒盐噪声,提出了一种基于模糊逻辑推理的方向中值滤波算法.该算法先利用椒盐噪声的特点,将图像像素点分为信号像素点和噪声像素点,然后利用模糊推理在4个方向上推理出最接近理想值的非噪声点代替当前噪声点.同时算法中采用一种简便的方法检测出噪声点所处的滑动窗口中的边和线.仿真结果表明,该算法能在有效抑制噪声的同时较好地保存图像的细节信息.     

地震速度场的趋势面分析及应用

建立地震速度场的数据主要来源于速度谱，速度的影响因素较复杂，而由速度谱数据过渡到地层的层速度与平均速度的各种方法都存在一定的局限性。在速度数据体中，异常数据较多。地震速度场的平均值与中值滤波趋势分析能较好地压制速度场中的异常数据和提高速度场数据的精度。用这种分析方法对某盆地Ｙ构造带Ｔ８层的平均速度数据进行了处理，效果十分显著。     

工件检测中基于方向码的图像模板匹配

针对在线工件的特点提出了一种新的工件检测办法.该算法提取方向码作为特征,分粗精两个步骤进行检测,首先计算模板和子图方向码并计算出方向码直方图,粗略的计算候选匹配点和工件旋转角度,然后,针对匹配候选点,利用于图和模板的方向码差值进行精匹配.该方法在工件位置发生旋转甚至是在遮档和光强引起的光照波动等情况下,也能较好的进行匹...     

Irregular Characteristics of Bond Interface Formation in Ultrasonic Wire Wedge Bonding

The mechanism of ultrasonic wire wedge bonding, one of the die/chip interconnection methods, was investigated based on the characteristics of the ultrasonic wire bonding joints. The Al-1%Si wire of 25 μm in diameter was bonded on Au/Ni/Cu pad and the joint cross-section was analyzed by scanning electron microscopy （SEM） and energy-dispersive X-ray spectroscopy （EDX）. The results indicated that it is irregular for the ultrasonic bond formation, non-welded at the centre but joining well at the periphery, especially at the heel and toe of the joint. Furthermore, the diffusion and/or reaction at the cross-section interface are not clear at C-zone, while there exists a strip layer microstructure at P-zone, and the composition is 78.96 at. pct Al and 14.88 at. pct Ni, close to the Al3Ni intermetallic compound. All these observations are tentatively ascribed to the plastic flow enhanced by ultrasonic vibration and repeated cold deformation driving interdiffusion between AI and Ni at bond interface.     

Effects of repeated exposures to severely cold environments on thermal responses of humans

Abstract

This study was conducted to investigate the effects of different exposure rates on thermal responses with the total cold exposure time the same under each of the conditions. After resting in a warm room (25°C) for 10 minutes, six male students wearing standard cold protective clothing entered an adjoining cold room (— 25°C). Each 5-, 10- and 20-minute cold exposure was repeated 12, 6 and 3 times, respectively. Each cold exposure was followed by a similar duration of rest at 25°C. Total cold exposure time was the same under the three conditions. Rectal temperature, skin temperatures, blood pressure, 17-hydroxycoyticoids (OHCS), counting task and subjective responses were measured. At the end of the cold exposure skin temperatures in the shorter exposures were higher than those in the other conditions, except on the foot. Discomfort due to cold was less in the shorter exposures and manifestation of discomfort was delayed. However, there were no differences among the three conditions in the fall of rectal temperature and urinary excretion of 17-OHCS, which are good indices of cold stress, Moreover, increase in blood pressure and decrease in counting task due to cold were not different among the three conditions. Even though the cold exposure time for each stay was short, when cold exposures were repeated frequently, cold stress of the whole body and decrease in manual task performance were the same as in the longer cold exposure.     

Effect of working position and cold environment on muscle activation level and fatigue in the upper limb during manual work tasks

Several occupational groups are exposed to periods of low ambient temperatures while performing manual work tasks outdoors. Work tasks typically include heavy lifting, tool handling, and overhead work. This study evaluated the effect of working position and cold environment on muscle activation level (%RMS_max) and fatigue in the upper limb during manual work tasks. Fourteen male participants (25 ± 3 years, 80.9 ± 6.4 kg, 182 ± 5 cm) completed a 2-h test protocol consisting of five test periods alternating with four work periods, wearing identical sets of clothing, under cold (−15 °C) and control (5 °C) conditions. The work periods consisted of manual work at the hip level, manual overhead work, and a lifting exercise. The test periods consisted of isometric maximal voluntary contractions (MVC) and seated rest. Skin temperatures decreased during cold exposure, especially in the extremities. %RMS_max in the forearm was higher in the cold condition both during overhead work and work at the hip level than that for the same work in the control condition, especially at the end of the test when the difference was approximately 25% (equating to 2–3 %RMS_max). For the middle deltoid muscle, the %RMS_max was approximately three times (or 10 %RMS_max) higher during overhead work than work at the hip level, but there was no additional cost of working in the cold. Signs of deltoid muscle fatigue (decrease in electromyography median power frequency and an increase in %RMS_max) were observed during the overhead work periods in both temperature conditions. No decrease in MVC, as a sign of overall muscle fatigue, was observed in either condition.Relevance to industryThis study demonstrated that when wearing suitable cold-weather protective clothing, the adverse effect of work posture is much higher than that of cold on muscle demand and physical strain.     

油田采出水Zeta电位和中值粒径对絮凝效果条件研究

该研究依据动态电泳光散射理论进行Zeta电位测定,利用多个激光源的光束投射测定中值粒径,采用絮凝沉降测定胶体颗粒的絮凝体积及沉降速度.着重考察不同采出水添加剂、聚醚类破乳剂、杀菌剂1227、阻垢剂EDTMP、咪唑啉类缓蚀剂与聚合氯化铝(PAC)复配对颗粒聚集Zeta电位、中值粒径、絮凝体积、沉降速度与颗粒聚集之间的关系...     

一种新型噪声检测中值滤波算法

本文提出了一种基于噪声检测的迭代中值滤波算法。该算法首先检测出噪声点,然后利用信号点对噪声点滤波。其中,噪声检测方法改进了Minmax方法。经过实验仿真并与其他滤波算法进行比较表明,该算法可以有效地去除图像中的脉冲噪声并且保留原图像的细节。