检索结果-南通市图书馆

Design and performance evaluation of a variable-rate orchard sprayer based on a laser-scanning sensor

International Journal of agricultural and Biological Engineering 2019年第6期12卷 51-57页

作者： Jichen Cai Xiu Wang Yuanyuan Gao Shuo Yang Chunjiang Zhao College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083China National Research Center of Intelligent Equipment for agriculture Beijing 100097China Key Laboratory of Agri-Informatics Ministry of AgricultureBeijing 100097China Beijing key laboratory of Intelligent Equipment Technology for agriculture Beijing 100097China

To improve the precision spraying strategy and reduce excessive pesticide application in orchards,an air-assisted sprayer integrated with a laser-scanning system was developed to realize the toward-target variable-rate spraying.In the spray control system,a method of calculating canopy gridding volumes was designed to ensure that the canopy was divided into a uniform grid size,a variable-rate spray model was used in the flow rate decision software to control the spray output according to the canopy gridding volumes and travel speed,and a method of saving and accessing spray data was used to control the spray delay.The effects of different grid sizes and travel speeds on the spray performance were evaluated by quantifying spray coverage uniformity inside tree canopies.The results showed that spray coverage uniformity declined with increasing grid width from 0.14 to 0.28 m although the mean spray coverage on each target location showed no significant differences.Additionally,there were no significant variations in mean spray coverage at speeds of 1.0,1.2 and 1.4 m/s for a tested tree of 1.6 m width and at any experimental speeds for a tested tree of 1.3 m width,which indicated that the variable-rate sprayer could provide good spray coverage uniformity under various travel speeds with a canopy size limitation.Compared with the same sprayer without the variable-rate spray function,the intelligent sprayer prototype realized effective toward-target spraying and avoided overspraying while providing sufficient spray coverage.

关键词： laser-scanning sensor variable-rate spray orchard precision sprayer pesticide application efficiency

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Comparative Analysis of the Purchase Price of Raw Milk in the World

引用

Asian agricultural Research 2014年第1期6卷 35-38页

作者： Xiaoxia DONG agricultural Information Institute of Chinese Academy of agricultural Sciences/Key Laboratory of Agri-Informatics Ministry of Agriculture/Key Laboratory of Digital Agricultural Early-warning TechnologyMinistry of Agriculture

This paper selects 20 countries from the major dairy producing continents such as Oceania,the Americas,Europe and Asia,for the comparative analysis of the purchase price of raw milk in the world. Based on the summarization of general features of the world raw milk prices,this paper elaborates the fluctuations in the purchase price of raw milk in Oceania,the Americas,Europe and Asia,respectively,and carries out the comparative study of the gap between the domestic purchase price of raw milk and the world purchase price of raw milk.

关键词： Raw milk Purchase price Comparative analysis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国东北玉米空间分布对气候变化的响应,1980–2010（英文）

引用

Journal of Geographical Sciences 2016年第1期26卷 3-14页

作者：李正国谭杰扬唐鹏钦陈浩张莉刘晗吴文斌唐华俊杨鹏刘珍环 Chinese Academy of agricultural Sciences Key Laboratory of Agri-informaticsMinistry of Agriculture/Institute of Agricultural Resources and Regional Planning Hunan Academy of agricultural Sciences Institute of Agricultural Economics and Regional Planning Sun Yat-sen University School of Geography and Planning

Based on county-level crop statistics and other ancillary information, spatial distri- bution of maize in the major maize-growing areas （latitudes 39°-48°N） was modelled for the period 1980-2010 by using a cross-entropy-based spatial allocation model. Maize extended as far north as the northern part of the Lesser Khingan Mountains during the period, and the area sown to maize increased by about 5 million ha. More than half of the increase occurred before 2000, and more than 80% of it in the climate transitional zone, where the annual ac- cumulated temperature （AAT） was 2800-3400 ℃.d. Regions with AAT of 3800-4000 ℃-d became more important, accounting for more than 25% of the increase after 2000. The ex- pansion of maize was thus closely related to warming, although some variation in the distri- bution was noticed across zones in relation to the warming, indicating that maize in northeast China may have adapted successfully to the warming by adjusting its spatial distribution to match the changed climate.

关键词： climate warming regional response spatial pattern Zea mays China

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Development of real-time laser-scanning system to detect tree canopy characteristics for variable-rate pesticide application

引用

International Journal of agricultural and Biological Engineering 2017年第6期10卷 155-163页

作者： Cai Jichen Wang Xiu Song Jian Wang Songlin Yang Shuo Zhao Chunjiang College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083China National Research Center of Intelligent Equipment for agriculture Beijing 100097China Key Laboratory of Agri-Informatics Ministry of AgricultureBeijing 100097China Beijing key laboratory of Intelligent Equipment Technology for agriculture Beijing 100097China

Improving pesticide application efficiency is increasingly important in orchard spraying.In this study,a laser-scanning system was designed to acquire gridding volumes of a tree to quantify the geometry characteristics of the tree canopy in real-time.A laser-scanning sensor mounted on a linear guide was utilized to measure the structure of a target tree canopy.A computer was used to receive measurement data from the laser scanner and obtain the movement distance of the laser-scanning sensor from a controller.An algorithm written with VC#program was designed to calculate gridding volumes of trees by recognizing valid measurement data from the laser scanner.laboratory evaluations were conducted on three kinds of regular objects,and the maximum relative errors of section volumes of the cuboid,triangular prism and cylinder objects were 3.3%,7.9%and 9.4%,respectively,which illustrated that the algorithm could calculate the section volumes in different parts of the objects with high accuracy.A conifer tree and an apple tree were chosen to verify detecting accuracy of the laser-scanning system at variable speeds and grid sizes.The variation coefficients of total volumes for each kind of the tree were 0.078 and 0.041,respectively,which indicated that the laser-scanning system could be applied to provide the gridding volumes of different canopy densities in real-time with good reliability for guiding a variable-rate sprayer.

关键词： laser-scanning system sensor tree canopy variable-rate spray pesticide application efficiency gridding volumes calculation algorithm

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A method for weighing broiler chickens using improved amplitude-limiting filtering algorithm and BP neural networks

引用

Information Processing in agriculture 2021年第2期8卷 299-309页

作者： Weihong Ma Qifeng Li Jiawei Li Luyu Ding Qinyang Yu Beijing Research Center for Information Technology in agriculture Beijing 100097China National Engineering Research Center for Information Technology in agriculture Beijing 100097China Key Laboratory of Agri-Informatics Ministry of AgricultureBeijing 100097China Beijing Engineering Research Center of agriculture Internet of Things Beijing 100097China

Broiler chickens are traditionally weighed by steelyard or platform scale,which is timeconsuming and labor-intensive.Broiler chickens usually exhibit stress-related behavior during weighing.The 3D camera-based weighing system for broiler chickens can only weigh the broiler chicken in the monitoring area.Usually,it makes poor weight prediction due to poor segmentation especially when the broiler chicken is flapping its wings.To solve these issues,we developed one simple and low-cost weighing system with high stability and accuracy.A validity value extraction method from dynamic weighing was proposed.Then,an improved amplitude-limiting filtering algorithm and a BP neural networks model were developed to avoid accidental interference.The BP neural networks model used daily weight gain,day-age,average velocity,and the weight data after filtering algorithm as the input layer.The weighing system was tested in a commercial Beijing Fatty Chickens house with Beijing Fatty Chickens.We tested thirteen groups of Beijing Fatty Chickens of different weights,from 500 g to 1800 g in intervals of 100 g,using the three different methods:no filtering algorithm or BP neural networks,only the improved amplitude-limiting filtering algorithm and a hybrid of the improved amplitude-limiting filtering algorithm and BP neural networks.The results showed that the hybrid algorithm had a better performance in minimizing the error,lowering from the original 6%down to 3%.The accurate weight data was transmitted to the remote service platform for further decision-making,such as activity analysis,feeding management,and health alerts.

关键词： Weighing of broiler chickens Improved amplitude-limiting filtering algorithm BP neural networks Dynamic weighing

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Micro-nondestructive detection of the moisture and ion of rice seeds during germination under salt stress

引用

International Journal of agricultural and Biological Engineering 2019年第2期12卷 103-110页

作者： Hongwei Yang Jianwei Ji Cheng Wang Liying Zhang Xiaodong Wang Ping Song Peng Song College of Information and Electrical Engineering Shenyang Agricultural UniversityShenyang 110866China National Research Center of Intelligent Equipment and Technology for agriculture Beijing 100097China Key Laboratory of Agri-Informatics Ministry of AgricultureBeijing 100097China Beijing key laboratory of Intelligent Equipment and Technology for agriculture Beijing 100097China Liaoning Rice Research Institute Shenyang 110161China

Salt stress is one of the major stress factors limiting rice productivity.Its damaging effects include water deficit due to osmotic stress,and ionic toxicity caused by ionic stress.It is very important to study the salt-tolerance mechanism of rice under salt stress,in order to improve the salt-tolerance capacity of rice and thereby increase the yield.In this experiment,the low field nuclear magnetic resonance(LF NMR)technique and the traditional dry-weight weighing method,the non-invasive micro-test technique(NMT)and the inductively coupled plasma emission spectrometry(ICP-AES)were applied to analyze the distribution of water and the flow of K^(+)and Na^(+)of rice seeds during germination under NaCl stress.The results suggested that for all different NaCl concentrations,as germination hours grew,the amplitude of NMR signals of the bound water that of the free water and the total amplitude all increased gradually.And the higher the NaCl concentration is,the weaker the increase trend is.In addition,the moisture content of the seeds and the total amplitude of NMR signals were positively correlated.The regression equation was y=191.53x+1463.6,the correlation coefficient was R=0.9823,and the determination coefficient was R2=0.9650.By this regression equation,the moisture content of each state of water during seed germination can be calculated.When without NaCl stress,the rice seeds absorbed K^(+)in the germination process.However,when under NaCl stress at different concentrations,K^(+)efflux was detected.The contents of K^(+)and K^(+)/Na^(+)were lower than that under the control condition.The higher NaCl concentration is,the lower the K^(+)and K^(+)/Na^(+)contents are.These results are in consistence with the K^(+)and Na^(+)contents detected by the inductively coupled technique.These empirical data offer a reference for the study of rice-seeds’response mechanism under salt stress during germination and the screening of germplasm resources,and also put forward a new method of biopsy micro-nondestructive test for plants

关键词： nuclear magnetic resonance(NMR) non-invasive micro-test(NMT) NaCl stress seed germination moisture dynamic ion flow

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Framework of SAGI agriculture Remote Sensing and Its Perspectives in Supporting National Food Security

引用

Journal of Integrative agriculture 2014年第7期13卷 1443-1450页

作者： SHI Yun JI Shun-ping SHAO Xiao-wei TANG Hua-jun WU Wen-bin YANG Peng ZHANG Yong-jun Shibasaki Ryosuke Key Laboratory of Agri-Informatics Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Earth Observation Data Integration and Fusion Research Initiative The University of Tokyo School of Remote Sensing and Information Engineering Wuhan University

Remote sensing, in particular satellite imagery, has been widely used to map cropland, analyze cropping systems, monitor crop changes, and estimate yield and production. However, although satellite imagery is useful within large scale agriculture applications （such as on a national or provincial scale）, it may not supply sufifcient information with adequate resolution, accurate geo-referencing, and specialized biological parameters for use in relation to the rapid developments being made in modern agriculture. Information that is more sophisticated and accurate is required to support reliable decision-making, thereby guaranteeing agricultural sustainability and national food security. To achieve this, strong integration of information is needed from multi-sources, multi-sensors, and multi-scales. In this paper, we propose a new framework of satellite, aerial, and ground-integrated （SAGI） agricultural remote sensing for use in comprehensive agricultural monitoring, modeling, and management. The prototypes of SAGI agriculture remote sensing are ifrst described, followed by a discussion of the key techniques used in joint data processing, image sequence registration and data assimilation. Finally, the possible applications of the SAGI system in supporting national food security are discussed.

关键词： SAGI agriculture remote sensing multi-platform data processing food security

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Contribution of Drought to Potential Crop Yield Reduction in a Wheat-Maize Rotation Region in the North China Plain

引用

Journal of Integrative agriculture 2014年第7期13卷 1509-1519页

作者： HU Ya-nan LIU Ying-jie TANG Hua-jun XU Yin-long PAN Jie Institute of Environment and Sustainable Development in agriculture Chinese Academy of Agricultural Sciences Key Laboratory of Agri-Informatics Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Public Meteorological Service Center Chinese Meteorological Administration

With consecutive occurrences of drought disasters in China in recent years, it is important to estimate their potential impacts on regional crop production. In this study, we detect the impacts of drought on wheat and maize yield and their changes at a 0.5＆#176;＆#215;0.5＆#176; grid scale in the wheat-maize rotation planting area in the North China Plain under the A1B climate change scenario using the Decision Support System for Agrotechnology Transfer （DSSAT） model and the outputs of the regional climate modeling system-Providing Regional Climates for Impacts Studies （PRECIS）. Self-calibrating palmer drought severity index was used as drought recognition indicator. Two time slices used for the study were the baseline （1961-1990） and 40 years of 2011-2050. The results indicate that the potential planting region for double crop system of wheat-maize would expend northward. The statistic conclusions of crop simulations varied considerably between wheat and maize. In disaster-affected seasons, wheat yield would increase in the future compared with baseline yields, whereas in opposite for maize yield. Potential crop yield reductions caused by drought would be lower for wheat and higher for maize, with a similar trend found for the ratio of potential crop yield reductions for both crops. It appears that the negative impact of drought on maize was larger than that on wheat under climate change A1B scenario.

关键词： drought yield DSSAT A1B scenario climate change

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mapping regional cropping patterns by using GF-1 WFV sensor data

引用

Journal of Integrative agriculture 2017年第2期16卷 337-347页

作者： SONG Qian ZHOU Qing-bo WU Wen-bin HU Qiong LU Miao LIU Shu-bin Key Laboratory of Agri-Informatics Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 P.R. China Remote Sensing Technology Center Heilongjiang Academy of Agricultural Sciences Harbin 150086 P.R.China

The successful launched Gaofen satellite no. 1 wide field-of-view （GF-1 WFV） camera is characterized by its high spatial resolution and may provide some potential for regional crop mapping. This study, taking the Bei＇an City, Northeast China as the study area, aims to investigate the potential of GF-1 WFV images for crop identification and explore how to fully use its spectral, textural and temporal information to improve classification accuracy. In doing so, an object-based and Random Forest （RF） algorithm was used for crop mapping. The results showed that classification based on an optimized single temporal GF-1 image can achieve an overall accuracy of about 83%, and the addition of textural features can im- prove the accuracy by 8.14%. Moreover, the multi-temporal GF-1 data can produce a classification map of crops with an overall accuracy of 93.08% and the introduction of textural variables into multi-temporal GF-1 data can only increase the accuracy by about 1%, which suggests the importance of temporal information of GF-1 for crop mapping in comparison with single temporal data. By comparing classification results of GF-1 data with different feature inputs, it is concluded that GF-1 WFV data in general can meet the mapping efficiency and accuracy requirements of regional crop. But given the unique spectral characteristics of the GF-1 WFV imagery, the use of textual and temporal information is needed to yield a satisfactory accuracy.

关键词： crop mapping GF-1 object-based Random Forest

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

How do temporal and spectral features .matter in crop classification in Heilongjiang Province, China？

引用

Journal of Integrative agriculture 2017年第2期16卷 324-336页

作者： HU Qiong WU Wen-bin SONG Qian LU Miao CHEN Di YU Qiang-yi TANG Hua-jun Key Laboratory of Agri-Informatics Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 P.R.China Remote Sensing Technology Center Heilongjiang Academy of Agricultural Sciences Harbin 150086 PR. China

How to fully use spectral and temporal information for efficient identification of crops becomes a crucial issue since each crop has its specific seasonal dynamics. A thorough understanding on the relative usefulness of spectral and temporal features is thus essential for better organization of crop classification information. This study, taking Heilongjiang Province as the study area, aims to use time-series moderate resolution imaging spectroradiometer （MODIS） surface reflectance product （MOD09A1） data to evaluate the importance of spectral and temporal features for crop classification. In doing so, a feature selection strategy based on separability index （SI） was first used to rank the most important spectro-temporal features for crop classification. Ten feature scenarios with different spectral and temporal variable combinations were then devised, which were used for crop classification using the support vector machine and their accuracies were finally assessed with the same crop samples. The results show that the normalized difference tillage index （NDTI）, land surface water index （LSWl） and enhanced vegetation index （EVI） are the most informative spectral features and late August to early September is the most informative temporal window for identifying crops in Heilongjiang for the observed year 2011. Spectral diversity and time variety are both vital for crop classification, and their combined use can improve the accuracy by about 30% in comparison with single image. The feature selection technique based on SI analysis is superior for achieving high crop classification accuracy （producers＇ accuracy of 94.03% and users＇ accuracy of 93.77%） with a small number of features. Increasing temporal resolution is not necessarily important for improving the classification accuracies for crops, and a relatively high classification accuracy can be achieved as long as the images associated with key phenological phrases are retained.

关键词： crop identification temporal feature spectral feature feature selection MODIS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：