一种基于偏好免疫网络多特征辨识的油茶果分选识别方法

针对油茶果采摘、脱壳后机器视觉分选效率不高的问题,提出一种多特征偏好人工免疫网络算法,该算法应用人工免疫网络的多目标优化与偏好数据库特征,提取油茶目标的颜色、形态多特征输入免疫网络进行仿真测试。试验结果表明,本文提出的多特征偏好免疫网络的识别率最高达到90%以上。相比单特征分选方法有了较大的提升,证明本文分选方法的有效性,并为农林业目标智能化分选辨识提供一种可行的方案。     

泥炭块制作机应用前景展望

介绍了泥炭块育苗技术的优点，分析了泥炭块制作机制作泥炭块的工艺流程及其关键技术，展望了泥炭块制作机的应用前景。     

语音符号在英语学习中的作用

每种语言都有自己的音节节拍规律,语言学习应从语音知识开始.语音符号具有浓烈的民族性,不同的民族有不同的语音系统,其中韵律是语言最核心的本质.朗读是掌握一门语言语音知识最基本也是最重要的手段.阅读离不开内部言语活动,语音符号有利于提高阅读理解能力.笔者通过多年的英语教学发现,语音符号在英语学习中起到了非常重要的作用.英语学习也不例外,英语语音符号是文字符号的基础,是打开文字符号大门的钥匙.所以笔者呼吁,英语教师们,尤其是少儿英语和小学英语的教师们在教学中应重视语音符号的教学,这样才能更好地提高英语教学并克服聋哑外语.     

专业教师下厂锻炼与教学改革的关系研究——以江苏财经职业技术学院粮食工程与管理系为例

为推动高职院校与行业更加广泛深入的合作，以江苏财经职业技术学院粮食工程与管理系为例，介绍其在校企合作方面的主要做法及取得有成效。根据师生参加粮食行业实践工作的经验，从行业指导、教学模式改革、双师型教师培养、教学过程反思等方面。分析高职院校深入行业开展科技服务与教学的必要性。     

树莓采摘机械研制必要性分析

随着树莓推广种植面积的不断增加,树莓人工采摘劳动强度大且效率低、成本高的问题已经严重影响到树莓产业的发展。在调查研究国内外树莓采摘机械化发展现状、市场需求情况和预期效益的基础上,分析研制树莓采摘机械的必要性,为促进我国树莓生产机械化发展提供依据。     

Detection of Ecballium elaterium in hedgerow olive orchards using a low-cost uncrewed aerial vehicle and open-source algorithms

BACKGROUND

Ecballium elaterium (common name: squirting cucumber) is an emerging weed problem in hedgerow or superintensive olive groves under no tillage. It colonizes the inter-row area infesting the natural or sown cover crops, and is considered a hard-to-control weed. Research in other woody crops has shown E. elaterium has a patchy distribution, which makes this weed susceptible to design a site-specific control strategy only addressed to E. elaterium patches. Therefore, the aim of this work was to develop a methodology based on the analysis of imagery acquired with an uncrewed aerial vehicle (UAV) to detect and map E. elaterium infestations in hedgerow olive orchards.

RESULTS

The study was conducted in two superintensive olive orchards, and the images were taken using a UAV equipped with an RGB sensor. Flights were conducted on two dates: in May, when there were various weeds infesting the orchard, and in September, when E. elaterium was the only infesting weed. UAV-orthomosaics in the first scenario were classified using random forest models, and the orthomosaics from September with E. elaterium as the only weed, were analyzed using an unsupervised algorithm. In both cases, the overall accuracies were over 0.85, and the producer's accuracies for E. elaterium ranged between 0.74 and 1.00.

CONCLUSION

These results allow the design of a site-specific and efficient herbicide control protocol which would represent a step forward in sustainable weed management. The development of these algorithms in free and open-source software fosters their application in small and medium farms. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

One hundred years of population ecology: Successes,failures and the road ahead

Population ecology is the most mature of the three subdisciplines of ecology partly because it has a solid mathematical foundation and partly because it can address the primary questions of distribution and abundance with experimental protocols. Yet there is much left to do to integrate our population knowledge into community and ecosystem ecology to help address the global issues of food security and the conservation of biodiversity. Many different approaches are now being developed to bring about this integration and much more research will be necessary to decide which if any will be most useful in achieving our goals of explaining the changes we see in the distribution and abundance of animals and plants. Food web ecology would appear to be the best approach at present because it uses the detailed information of the population ecology of particular species in combination with data on consumer–resource interactions to apply to the applied problems of biodiversity conservation, food security, pest management and disease prevention. If we can use our understanding of population ecology to address the practical problems of our time in a creative way, we will benefit both the human population and the Earth's biodiversity. Much remains to be done.     

海南岛几种优势树种构筑型的研究

对海南 9种优势树种构筑型进行研究 ,通过对树木分枝方式和发芽方式的细致观察和描述 ,发现有 1种属Massart型 ,1种属Troll型 ,7种属Rauh型。对这 9种树木的构筑型特征与国外的研究进行了比较 ,确定了构筑模式与属及发芽模式与属之间的关系。     

Signals of summer drought in crown condition data from the German Level I network

Crown transparency estimates of Scots pine, Norway spruce, common beech, pedunculate and sessile oak, annually surveyed between 1990 and 2004 within a grid over Germany, provide a suitable response variable to study drought effects on forest trees. Major climatic factors, available on a monthly basis as plot-specifically interpolated values and parameters of site and stand conditions, biotic and other relevant factors were used as predictors in different cross- and length-sectional, and longitudinal models. Stand age is a considerable and most constant driver of crown transparency in all species. Pine, spruce and beech responded—mainly with a delay of 1 year—with some foliar loss in areas where there was a surplus of temperature after the generally hot and dry summer of 2003. Parallel time-series analyses delivered species-specific geographic large-scale patterns with delayed or recent precipitation deficits or temperature surpluses. Even if beech is partly responding in current years with leaf loss towards precipitation surpluses, defoliation is especially high 1 year after hot summers, partly a result of high seed sets after such summers. Crown condition of oak responds in dry and warm areas according to the drought stress hypothesis, however, in cool and wet mountainous ranges oak responds after wet summers with higher defoliation. Longitudinal approaches revealed for all 4-tree species significant relationships between crown condition and deviations from the long-term means of temperature, precipitation but also global radiation and wind speed. Results do not always match the drought stress hypothesis, however, this is not to expect considering the heterogeneous site, stand and climatic conditions across Germany. Complex interactions of climatic and biotic factors also impede simple relationships. Soil-related clusters reveal higher sensitivity of spruce and beech towards climatic drought factors on more acid soils with thin humus layers. Also clusters constructed from plot-specific courses of defoliation reveal groups with rather closer relationships like a group of pine plots in the Oberpfalz, which seems to be especially sensitive to summer drought.     

基于虚拟仪器技术的自动立木整枝机离合弹簧性能测试系统的设计

离合弹簧在自动立木整枝机变速换向过程中起着重要的作用.本文分别从硬件设计和软件设计两方面介绍了基于虚拟仪器技术开发的自动立木整枝机离合弹簧性能测试系统,该测试系统支持不同类型信号的多通道数据采集和处理,能够实现信号的产生、数据实时采集、数据处理、分析、显示及存储等功能,并通过多次测试离合弹簧的实验,验证了该测试系统的实用性和可靠性.