混合动力叉车动力系统构型设计与动力装置参数匹配

分析了各种混合动力车辆动力组合形式的优缺点以及叉车的运行工况,提出了适合叉车的轴动力组合式并联混合动力构型;对发动机、ISG电机、发电机和镍氢电池等主要元件进行了动力参数设计;并对柴油机叉车和混合动力叉车进行了仿真计算,结果表明了混合动力叉车有良好的节能效果。     

Application of time-frequency distribution correlating and matching method in signal extraction

The time-frequency coupling relation between useful non-stationary components and noises bring great difficulties to the realization of de-noising for non-stationary signals,which can not be solved by classic de-noising method in time or frequency domain. The principles of short time Fourier transform(STFT),Wigner-Ville transform,Chirplet adaptive decomposition are analyzed,and then a novel de-noising method for non-stationary based on joint time-frequency distribution is proposed. In this method,the analyzed signal WVD is seen as the combination of auto-WVD and cross-term WVD. Firstly,STFT energy spectrum of the analyzed signal is used as template to cross-correlate with its corresponding WVD in order to obtain the satisfactory time-frequency distribution with high time-frequency resolution and without cross-term interferences. Secondly,the useful components are decomposed as Chirplet function using the two-dimension least square fitting method,and then are extracted out to reconstruct for noise suppression. Finally,the computer simulation results verify the effectiveness of this proposed method. Its application in gearbox fault diagnosis indicates that with the method the extracted cycle of the gearbox vibration impulses has a good consistency with the corresponding fault frequency.     

CBERS-02影像条带噪声处理方法探讨

选择覆盖内蒙古阿荣旗地区CBERS02-CCD数据,采用直方图匹配法、主成分分析法、矩匹配法、低通滤波法、小波变换法等空间域和频率域共5种方法,结合定性分析和定量计算对比评价,结果表明,小波变换法可以有效去除条带噪声,而且在细节突出方面也存在一定优势;矩匹配法容易改变地物本身的光谱信息,虽然条带去除效果较好,但不适宜CBERS-02影像数据图像与处理工作;主成分分析法不仅没有去除条带,在某种程度上,反而加强了条带噪声。     

优质米加工及降碎措施

南方产优质稻谷粒形长,导致加工过程碎米率高、出米率低、生产成本高。实践表明,做好品种的选育、生产管理和收储,优化大米加工工艺流程及设备匹配,是降低优质米加工破碎率及提高经济效益的有效措施。     

具有极小Hosoya指数的含圈共轭图

图G=(V(G),E(G))为简单连通共轭图,即含有完备匹配的图,其顶点集为V(G),边集为E(G).n,m表示含有n(n≥8)个顶点m(n≤m≤n+2n-2)条边的共轭图集合.用m(G,k)表示G中恰含k条边的匹配个数.z(G)表示图G的Hosoya指数,即G的所有匹配的总数.对于任何一个共F轭图G,都存在一个完备匹配.把G的边集分成两个子集,其中一个子集为图G的完备匹配所含的边,记为M(G),另一个子集为图G除完备匹配之外剩余的边,记为Q(G).对于G中任一个k-匹配,都可以从完备匹配M(G)中选j(0≤j≤k)条边,再从Q(G)中选择k-j条边,且保证所选的k条边互不相邻.如果对任意G1,G2∈n,m和k≤2n,都满足m(G1,k)≤m(G2,k),那么,就可以证明∑k2n=0m(G1,k)≤∑k2n=0m(G2,k),即z(G1)≤z(G2).本文用这种排列组合的方法研究并刻画了n,m中具有最小、次小Hosoya指数的极值图.     

谈西部生态建设的几个问题

在生态林规划中,应注意立地以水为主的生态负荷能力,使种植材料的生态习性与立地状况相适应.作好树种选择与树种搭配.扩大乡土树种、本地种源和灌木的种植比例,不要营造大面积纯林.在遗传改良品种的使用上,认为多无性系复合品种和实生繁殖材料,更有利于对本地环境的适应.     

A fast quantitative identification algorithm of colorimetric visual-sensor-array based on basic units matching

There are many difficulties to process a colorimetric visual-sensor-array by traditional processing methods, such as complicated manual analysis due to many data and hard to finish varieties and concentrations identification simultaneously, etc. In view of colorimetric-sensor-array’s same location response to the same gas, a fast quantitative identification algorithm of colorimetric visual-sensor-array based on basic units matching which can solve these problems is proposed. First, denoising and feature extraction are processed by setting experienced threshold to reduce redundancies and lessen manual analysis. Second, a creative qualitative analysis method based on basic units is put forward, which not only reduces computation, but also increases efficiency and precision. Finally, a ANFIS of NH3 concentration recognition utilizing advantages of fuzzy logic and neural network is used to distinguish low concentration NH3. The advantage of this algorithm is that varieties and concentrations of different gases could be detected successively, solving the problem of recognition errors caused by characteristic data infection when varieties and concentrations of different gases are detected simultaneously.The results of template matching based on basic units show that the classification accuracy of NH3, Cl2 and SO2 are 100%. The low concentration NH3 classification accuracy is also very high after species identification with measurement errors below 5%.     

基于HOG特征和SVM的棉花行数动态计数方法

正确地进行棉花行数的动态计数是保证视觉植保车在田端横移过程中实现准确定位的前提。该研究以植保期间的棉花作物为研究对象,提出通过方向梯度直方图(Histogram of Oriented Gradient,HOG)和支持向量机(Support Vector Machine,SVM)实现棉田的棉花行动态计数方法。为了减少棉花行之间的粘连,以及缺苗和倒伏对棉花行识别造成的影响,设置图像的感兴趣区域(Region of Interest,ROI);为了减小相机抖动、光照变化以及刮风对动态数行造成的影响,使用HOG-SVM模型在视频序列图像ROI区域内窗口滑动检测,将棉花行和行间背景分别设置正、负样本,通过提取二者HOG特征、多次训练获得SVM分类器参数,固化HOG-SVM模型,再使用非极大值抑制(Non-Maximum Suppression,NMS)进行窗口的归一,通过归一化互相关(Normalized Cross Correlation,NCC)模板匹配实现棉花行的动态跟踪和计数。结果表明,该方法可以准确地对棉花行实现动态计数,有很好的泛化能力,识别率高于90%,平均每帧检测时间为32 ms,满足实际田间作业要求,可作为视觉植保车在地头横移的距离依据。     

Reducing maize yield gap by matching plant density and solar radiation

Yield gap exists because the current attained actual grain yield cannot yet achieve the estimated yield potential. Chinese high yield maize belt has a wide span from east to west which results in different solar radiations between different regions and thus different grain yields. We used multi-site experimental data, surveyed farmer yield data, the highest recorded yield data in the literatures, and simulations with Hybrid-Maize Model to assess the yield gap and tried to reduce the yield gap by matching the solar radiation and plant density. The maize belt was divided into five regions from east to west according to distribution of accumulated solar radiation. The results showed that there were more than 5.8 Mg ha~(–1) yield gaps between surveyed farmer yield and the yield potential in different regions of China from east to west, which just achieved less than 65% of the yield potential. By analyzing the multi-site density experimental data, we found that the accumulated solar radiation was significantly correlated to optimum plant density which is the density with the highest yield in the multi-site density experiment(y=0.09895 x–32.49, P0.01), according to which the optimum plant densities in different regions from east to west were calculated. It showed that the optimum plant density could be increased by 60.0, 55.2, 47.3, 84.8, and 59.6% compared to the actual density, the grain yield could be increased by 20.2, 18.3, 10.9, 18.1, and 15.3% through increasing plant density, which could reduce the yield gaps of 33.7, 23.0, 13.4, 17.3, and 10.4% in R(region)-1, R-2, R-3, R-4, and R-5, respectively. This study indicates that matching maize plant density and solar radiation is an effective approach to reduce yield gaps in different regions of China.