松杨栅锈菌担孢子显微图像识别方法

针对松杨栅锈菌(Melampsora larici-populina)担孢子萌发数量计数问题,提出了利用图像处理技术实现对松杨栅锈菌担孢子显微图像的识别及自动计数。首先,运用形态学重建滤波算法去除松杨栅锈菌担孢子显微图像噪声;然后利用二维阈值化进行图像分割;再对分割后的松杨栅锈菌担孢子显微图像作距离变换;最后利用分水岭算法对松杨栅锈菌担孢子显微图像进行有效分割,实现了对分水岭算法过分割问题的改进。利用孔洞检测算法,实现了松杨栅锈菌担孢子的自动计数。     

GIS和Voronoi图在哈尔滨城市公园绿地布局中的应用

将哈尔滨市2009年GIS图和实地调研相结合,运用距离衰减和Voronoi图分析方法估计了哈尔滨城市公园绿地的服务总人数、面积及单位面积服务的人数,并对哈尔滨城市公园绿地布局进行了分析评价。结果表明:湿地公园、丁香公园、体育公园每公顷服务人数均小于300人,公园绿地发展良好;开发区景观广场、乐松广场、长青公园、建国公园、清滨公园、太平公园,尚志公园每公顷面积服务人数均已超过40 000人,无法满足周围游人的需要。根据研究结果提出了3点建议:局部地段建立新的公园绿地;加强对公园基础服务设施的建设和养护资金的投入;在郊区建立新的公园。     

基于单目视觉的前方车辆探测方法

介绍了采用单目视觉技术获取前方车辆多元信息的方法。利用单帧图像识别出的路径标线建立初始感兴趣区 ,并对目标进行初步探测 ;建立识别感兴趣区 ,应用对称性测度确认前方车辆是否存在 ,并寻找出前方车辆的对称轴 ;在连续序列图像中 ,利用 Kalm an预估器进行目标跟踪 ;建立基于静态图像处理和摄像机内部参数标定的单目视觉测距方法并进行相关试验验证。     

鄱阳湖长江江豚同步监测及种群动态分析

为支撑鄱阳湖长江江豚保护方案制定,及时准确掌握鄱阳湖长江江豚种群动态,2019年11月-2021年11月开展了4次同步监测,并采用 Distance 7.4 软件估算了其种群数量和密度。研究结果表明,总有效航程为1846 km,累计在429个位点观测到长江江豚,累计观测到长江江豚1001头次,母子豚130对次。2021年11月在139个位点观测378头个体,2019年11月仅在123个位点观测到225头。两年间鄱阳湖长江江豚观测个体数量增长了68%,观测位点数量增长了13.0%,估算的种群密度也增长49.2%。鄱阳湖长江江豚在集群规模方面,1-2头个体组成群体的频次最大,占比60.43%-90.24%,年际间差别较大,占比逐年下降;5头（含）以上群体,占比4.88%-12.20%,占比逐年上升,均与水位关系不明显。鄱阳湖长江江豚平均遇见率为 0.418-0.804头/ km,不同水位差别较大,低水位遇见率高,2021年11月长江江豚以及母子豚遇见率和幼豚所占比例均最高,说明长江江豚种群数量、幼体和可育雌性群体在种群中所占比例均呈现稳中有增趋势,表明鄱阳湖长江江豚种群可能已经实现了正增长。     

茶文化距离对茶叶贸易拓展影响的研究综述

本文分别从相关概念及理论研究,文化距离对贸易拓展的影响、文献述评三个方面进行了详细的综述,期望对茶文化距离对茶叶贸易拓展影响的研究有一定的参考作用。     

Analysis on Three -Dimensional Numerical Controlled Last Machining Algorithm

On the basis of applying three dimensional discrete formative technology to describing last surface, working principle of numerical controlled last carving machine is briefly introduced. Then the algorithm of ascertaining milling cutter machining position during the machining process is analyzed in detail. We establish a three dimensional reference frame with spatial analytic geometry and obtain the spatial equation of milling cutter rotary surface. According to last machining character, we put forward a machining algorithm named Minimal Distance Method and is used to calculate the milling cutter machining position. Finally, the glabrous degree of last made by us has reached the conventional demand.     

The agronomic and economic benefits of fertilizer and mulch use in highland banana systems in Uganda

Banana is the most important food crop in Uganda. However, there has been a decline in productivity, attributed to declining soil fertility, drought, pests and diseases and crop management factors. This study aimed to explore the possibility of increasing yields through the use of fertilizer and mulch, and to evaluate the benefits of these inputs across the major banana producing regions in Uganda. This study was carried out in 179 smallholder plots in Central, South, Southwest and East Uganda in 2006/7. Half of the plots were ‘demonstration plots’ of an agricultural development project, while the other half were neighboring farmer plots that acted as ‘control’. Demonstration plots received mineral fertilizer (100% of plots), averaging 71 N, 8 P, 32 K kg ha⁻¹ yr⁻¹ and external mulch from grass and crop residues (64% of plots), whereas control plots received no mineral fertilizer and little external mulch (26% of plots). Demonstration plots had significantly (P ? 0.05) higher yields than control plot in Central, South and Southwest, but average yield increases varied from 4.8 t ha⁻¹ yr⁻¹ (Southwest) to 8.0 (Central), and 10.0 (South). Average weevil corm damage (3%) and nematode-induced root necrosis (7%) was low and similar for both plot types, so yield increases could only be explained by the use of fertilizer and mulch. The highest demonstration plot yield increases were observed where fertilizer addressed key nutrient deficiencies identified using the compositional nutrient diagnosis approach. Farm gate bunch prices declined from 0.17 (Central Uganda) to 0.07 USD kg⁻¹ (Southwest Uganda). Consequently, average marginal rate of return (MRR) of fertilizer and mulch use ranged from 0.1 (Southwest) to 5.8 (Central). The technologies were likely to be acceptable to farmers (MRR ? 1.00) up to 160 km away from the capital. Fertilizer use is likely to be acceptable in all regions (MRR = 0.7-9.4) if local fertilizer prices of 2006/7 (average USD 0.56 kg⁻¹ of fertilizer) declined by 50%. Doubling of fertilizer prices is likely to make fertilizer use unacceptable beyond 100 km away from the capital. The study concludes that there is scope for increased input use in banana systems in Uganda, but that regional variations in crop response, input/output prices, and price fluctuations have to be taken into account.     

实验室条件下鱼类视角与个体邻近距离关系的探究

在麦穗鱼（Pseudorasbora parva）鱼群中,随着邻居鱼的靠拢,其影像在本鱼眼睛中占的视角越大。为了进一步探究其他的鱼群是否也存在相同的规律,本实验选用个体体长较小的喜成群的红鼻剪刀鱼（Hemigrammus rbodostomus）[由30尾组成,平均体长：（20.3±0.2）mm]作为对比研究对象。将其放置在水深5cm的水族缸（78.0cm×52.0cm×65.0cm）中,使用摄像机从正上方拍摄鱼群影像。逐幅提取鱼群影像中各个体的头部、质心（近头部1/3处）、尾部的二维数据,经过数据处理,分析视角与NND间的关系。结果表明：1）红鼻剪刀鱼与麦穗鱼的视角均集中在80o内,即本鱼观察邻居鱼的视角不大于80度。2）在体长差异较大的两种鱼群中,邻近个体占据本鱼的视野范围不会因为鱼体的增大而增加。3）邻近个体占据本鱼视野的最大视角与两者NND间满足以下关系：xy=A,y为视角（用弧度表示）,x为NND（单位:BL）,A为常数。该规律适用于麦穗鱼与红鼻鱼群体。4）该关系式表示,当邻居鱼靠近本鱼时,为了避免碰撞,鱼类个体用视角作为控制的主要参数,调整相互距离;此表明视觉在起主导作用,而侧线,嗅觉、电感觉、磁感觉等即使起作用,也处于次要的地位。     

网格技术在现代远程教育中的应用研究

网格技术是实现网络信息资源共享的技术之一,已成为当前国际计算技术研究的热点和前沿领域,网格技术的不断发展和完善必然会推动现代远程教育的发展.本文阐述了网格技术的概念及特点,提出了教育网格的系统框架.     

Assessing multiple dimensions of distributional justice: Access,biodiversity and landscape structure of green spaces for multiple social groups of the Metropolitan Region of Santiago de Chile

It is broadly recognized the value of green spaces to human well-being and health, hence several cities are taken actions for improving their existence in urban areas. However, it is also recognized that the distribution of those green spaces is not reaching all communities evenly. Several studies on distributional justice have assess. the disparities on the distribution of green spaces worldwide but they tend to focus on. the quantity or the accessibility from residences to green spaces. We proposed to. assess distributional justice as a multidimensional indicator that incorporates size, quantity, quality, access to biodiversity and distance traveled towards visiting a green. space to enrichen our evaluation of distributional justice and disclose disparities further. from green space availability. By using the Metropolitan Region of Santiago as a case. study we evaluated the distributional justice of green spaces by multiple social groups. based on a combination of surveyed, measured and collected spatially explicit data. Our results disclosed that low social status communities have access to green spaces. of smaller size, more dispersed, on lesser amounts and poorer on bird richness than. higher social status communities. Lower social status communities traveled more to. visit green spaces of higher quality and mostly move only one class up in the social. status. Our research showed larger complexities in distributional justice of green. spaces which should be evaluated and incorporated in decision making towards. greening.