基于三轴加速度传感器的山羊行为特征分类与识别

为分类并识别山羊的典型日常行为特征,以半封闭圈养的波尔山羊为研究对象,利用三轴加速度传感器对山羊的三轴加速度数据进行采集,利用K-means聚类算法对采集的数据集进行反复叠加训练得到较为稳定的聚类中心,同时利用全程的视频监控结合动作发生的时间识别并验证山羊的4种典型日常行为。结果表明,将三轴加速度传感器部署在山羊羊角处基本无明显应激反应,并且此传感器可以连续不间断地记录山羊的行为特征参数,对山羊的躺卧、站立或慢走、采食、跨跳等典型日常行为识别的准确率达87.76%,为山羊福利及山羊疾病预测模型的建立奠定了基础。     

Horizontal distribution and seasonal variability of the epipelagic chaetognath Sagitta elegans in relation to hydrography in the western subarctic Pacific Ocean

The spatial distribution and seasonal variability of epipelagic chaetognaths along the Kurile Islands and off south-east Hokkaido, in the western subarctic Pacific Ocean. were investigated during the period from May 1990 to October 1992. Sagitta elegans was the dominant species among the epipelagic chaetognaths in the study area. Juvenile S. elegans were distributed mainly along the path of the mixed water which was determined by the acceleration potential anomaly (APA) at the iso-pycnal density surface of 26.6 σθ. The location of the path of The mixed water meandered around cyclonic and anticyclonic eddies. Catches of S. elegans were made at temperatures ranging from 4.5 to 22.2C. The juvenile distribution, however, was mostly restricted to between 1 and 4C of the potential temperature determined at the isopycnal density surface of 26.6 σθ. Variability in the juvenile abundance within the path of the mixed water could be caused by predation rather than by food limitation because microzooplankton, which are known to he prey for juveniles, were abundant enough to meet the food requirements of juveniles in the study area. Adults occurred in spring (April-May) and young individuals (juvenile and stage 1) were abundant in summer (June-July), when a strong thermocline developed. The main spawning period appears to be during April-May, with a possible second spawning period in the autumn.     

Monitoring the spawning behaviour of chum salmon with an acceleration data logger

Abstract –  The continuous observation of salmon behaviour in some wild environments can be extremely difficult. We recorded spawning behaviour of female chum salmon ( Oncorhynchus keta ) in the field simultaneously using visual observation and fish-borne data loggers with two-axis accelerometer sensors. Using only acceleration records, behaviours were successfully classified into the eight well-known components of spawning behaviour: swimming, nosing, exploratory digging, nest digging, probing, oviposition, covering and post-spawning digging. To understand how the female chum salmon modulates spawning behaviours in relation to changes in environmental conditions, we compared the behaviours of salmon during normal flow of clear water to those of salmon during the heavy flow of turbid water after a storm. Salmon in the normal flow showed all eight behaviours, whereas salmon in the heavy flow showed only three behaviours: swimming, nosing and exploratory digging. The proportion of time spent on swimming was greater in the heavy flow than in the normal flow (mean of 98.47% vs. 92.84%). Moreover, the proportion of tail beating in swimming was greater in the heavy flow (77.86%) than in the normal flow (15.63%). Our results indicate that the behaviour of female chum salmon was strongly affected by the heavy flow of turbid water after a storm. The recording of accelerations is a promising method for clarifying the spawning behaviour of salmonids in the wild where continuous visual observation is too difficult.     

基于无线网桥传输气吸式免耕播种机振动测试系统设计

针对气吸式免耕播种机在空旷的田间试验不便应用有线传输的特点,采用加速度传感器测量振动的方法,设计了一种综合无线传输技术和振动信号采集与分析的振动测量系统。系统选用Ti3058k-16M的无线网桥、加速度传感器和数据采集卡实现了振动测量信号的采集和无线传送,Mat Lab分析处理采集到的数据。试验表明:系统在田间试验稳定性好、抗干扰能力强、网桥传输数据范围广、便捷实用,可为气吸式免耕播种机的田间测振试验提供方便。     

基于Labview的汽车ASM排放检测系统的开发设计

针对加速模拟工况的检测要求,利用Labview软件为平台,运用动态链接库技术,独立地设计出在用汽车的排放污染物检测系统。该系统实现了数据的输入输出、检测参数的采集、系统控制及数据分析处理等功能。该系统软件功能齐全,界面明了,容易操作,开发费用低,实用性强。     

四轮转向车辆操纵稳定性仿真分析

采用线性二自由度汽车模型,建立汽车四轮转向的运动微分方程式,从而对四轮转向汽车进行转向特性的进一步研究。在建立四轮转向汽车操纵动力学的模型基础上,借助MATLAB/Simulink模块对四轮转向汽车的动力学响应进行仿真分析,并将仿真结果与传统的前轮转向汽车作对比。仿真结果表明:四轮转向汽车在高速行驶时具有更好的操纵稳定性。     

7个水稻品种(系)的光周期反应特性

在人工气候室中,研究了7个不同类型水稻品种(系)的抽穗期对16h 长光照和10h 短光照的反应特性.结果表明:(1)不论是早稻还是晚稻,籼稻还是粳稻,均存在明显的“长日促进期”,把水稻基本营养生长期分为长日亚期(BVP—Ⅰ)和短日亚期(BVP—Ⅱ)是合理的;(2)长日照对不同品种有不同程度的抽穗阻滞效应;(3)强感光的晚稻品种未观察到长日补偿期,在连续16h 长光照下未能进入幼穗分化.     

小球弹跳运动中混沌现象的模拟与研究

介绍了小球在简谐振动台面上弹跳运动的运动学方程．计算机模拟了从规则运动到无规则运动的各种动力学行为，还得出；表征碰撞耗散的恢复系数α及振动台面加速度的幅值与重力加速度之比β两个参量对小球的弹跳运动行为有重要影响。     

工农－5型手扶拖拉机手把振动的测试分析及评价

通过理论分析和振动测试，探索了工农－５型手扶拖拉机手把振动主要振源及其振动特性，并根据国际标准ＩＳＯ５３４９进行了振动评价，发现手把振动的主要激励源是发动机。研究结果为手拖手把减振装置的研制提供了理论依据。