There are dozens or hundreds of grid-connected inverters for large-scale photovoltaic power plants.In order to facilitate the study of the impact that large-scale photovoltaic power plants have on the power system whi...There are dozens or hundreds of grid-connected inverters for large-scale photovoltaic power plants.In order to facilitate the study of the impact that large-scale photovoltaic power plants have on the power system while avoiding the need to establish a detailed model for each inverter,it is necessary to establish the equivalent model of large-scale photovoltaic power plants.Power generation units of the same type are combined by K-means clustering algorithm to reduce the simulation scale in number.According to the actual data of Shenmu large-scale grid-connected photovoltaic power station,employing RT-LAB software is used to conduct simulation verification and error analysis.The simulation results verify the proposed clustering equivalent modeling method is effective and can accurately track photovoltaic power station’s dynamic characteristics.展开更多
The continuous development of robot technology has made phenotype detection robots a key for extracting and analyzing phenotyping data in agriculture and forestry.The different applications of agricultural robots and ...The continuous development of robot technology has made phenotype detection robots a key for extracting and analyzing phenotyping data in agriculture and forestry.The different applications of agricultural robots and phenotype detection robots were discussed in this article.Further,the structural characteristics and information interaction modes of the current phenotype detection robots were summarized from the viewpoint of agriculture and forestry.The publications with keywords related to clustering distribution were analyzed and the currently available phenotype robots were classified.Additionally,a conclusion on the design criteria and evaluation system of plant phenotype detection robots was summarized and obtained,and the challenges and future development direction were proposed,which can provide a reference for the design and applications of agriculture and forestry robots.展开更多
Background： Ecosystem representation is one key component in assessing the biodiversity impacts of land-use changes that will irrevocably alter natural ecosystems. We show how detailed vegetation plot data can be use...Background： Ecosystem representation is one key component in assessing the biodiversity impacts of land-use changes that will irrevocably alter natural ecosystems. We show how detailed vegetation plot data can be used to assess the potential impact of inundation by a proposed hydroelectricity dam in the Mokihinui gorge, New Zealand, on representation of natural forests. Specifically we ask： 1） How well are the types of forest represented Locally, regionally, and nationally; and 2） How does the number of distinct communities （i.e. beta diversity） in the target catchment compare with other catchments nationally？ Methods： For local and regional comparisons plant species composition was recorded on 45 objectively located 400 m2 vegetation plots established in each of three gorges, with one being the proposed inundation area of the Mokihinui lower gorge. The fuzzy classification framework of noise clustering was used to assign these plots to a specific alliance and association of a pre-existing national-scale classification. NationaLly, we examined the relationship between the number of alliances and associations in a catchment and either catchment size or the number of plots per catchment by fitting Generalised Additive Models. Results： The four alliances and five associations that were observed in the Mokihinui lower gorge arepresent in the region but limited locally. One association was narrowly distributed nationally, but is the mostfrequent association in the Mokihinui lower gorge; inundation may have consequences of national importance to its long-term persistence. That the Mokihinui lower gorge area had nearly twice as many plots that could not be assigned to pre- existing alliances and associations than either the Mokihinui upper or the Karamea lower gorges and proportionally more than the national dataset emphasises the compositional distinctiveness of this gorge. These outlier plots in the Mokihinui lower gorge may be unsorted assemblages of species or reflect sampling bias or that native- 展开更多
There are 463 species of woody plant, belonging to 166 genera and 70 families in Shanxi, North China. The floristic composition types of genera and species are abundant, in which the compositions distributed in tempe...There are 463 species of woody plant, belonging to 166 genera and 70 families in Shanxi, North China. The floristic composition types of genera and species are abundant, in which the compositions distributed in temperate zones (including North Temperate, Old World Temperate and Temperate Asia), having 62 genera, are dominant and account for 38.27% in total genera (except for Cosmopolitan), and they are major constructive or dominant species of vegetation in Shanxi. The floristic compositions of woody plants of Shanxi, Hebei, Beijing, Shandong, Henan, Jiangxi and Inner Mongolia were studied comparatively by using diversity index, principal component analysis(PCA) and groupaverage clustering, respectively. The floristic composition of Shanxi was considerably similar to that of Hebei, Beijing and Shandong because they shared a lot of genera, specially genera distributed in temperate regions, such as Rosa, Quercus, Populus, Salix, Acer, Ulmus, Pinus etc. and their ecoenvironment were considerably similar. However, the flora of Shanxi was comparatively different from that of Henan, Jiangxi and Inner Mongolia by reason that there were distinct differences among their ecogeographic conditions, floristic compositions and constructive or dominant species of dominant vegetation types. 展开更多
基金Supported by National Youth Natural Science Foundation Project(51707053)and Anhui Youth Natural Science Fund Project(1808085-QE155).
文摘There are dozens or hundreds of grid-connected inverters for large-scale photovoltaic power plants.In order to facilitate the study of the impact that large-scale photovoltaic power plants have on the power system while avoiding the need to establish a detailed model for each inverter,it is necessary to establish the equivalent model of large-scale photovoltaic power plants.Power generation units of the same type are combined by K-means clustering algorithm to reduce the simulation scale in number.According to the actual data of Shenmu large-scale grid-connected photovoltaic power station,employing RT-LAB software is used to conduct simulation verification and error analysis.The simulation results verify the proposed clustering equivalent modeling method is effective and can accurately track photovoltaic power station’s dynamic characteristics.
基金funded by the Construction of Collaborative Innovation Center of Beijing Academy of Agricultural and Forestry Sciences(KJCX201917)Beijing Nova Program(Z211100002121065)Science and Technology Innovation Special Construction Funded Program of Beijing Academy of Agriculture and Forestry Sciences(KJCX20210413).
文摘The continuous development of robot technology has made phenotype detection robots a key for extracting and analyzing phenotyping data in agriculture and forestry.The different applications of agricultural robots and phenotype detection robots were discussed in this article.Further,the structural characteristics and information interaction modes of the current phenotype detection robots were summarized from the viewpoint of agriculture and forestry.The publications with keywords related to clustering distribution were analyzed and the currently available phenotype robots were classified.Additionally,a conclusion on the design criteria and evaluation system of plant phenotype detection robots was summarized and obtained,and the challenges and future development direction were proposed,which can provide a reference for the design and applications of agriculture and forestry robots.
基金funded by Meridian Energy Limited,New Zealandby Core funding for Crown Research Institutes from the New Zealand Ministry of Business,Innovation and Employment’s Science and Innovation Group
文摘Background： Ecosystem representation is one key component in assessing the biodiversity impacts of land-use changes that will irrevocably alter natural ecosystems. We show how detailed vegetation plot data can be used to assess the potential impact of inundation by a proposed hydroelectricity dam in the Mokihinui gorge, New Zealand, on representation of natural forests. Specifically we ask： 1） How well are the types of forest represented Locally, regionally, and nationally; and 2） How does the number of distinct communities （i.e. beta diversity） in the target catchment compare with other catchments nationally？ Methods： For local and regional comparisons plant species composition was recorded on 45 objectively located 400 m2 vegetation plots established in each of three gorges, with one being the proposed inundation area of the Mokihinui lower gorge. The fuzzy classification framework of noise clustering was used to assign these plots to a specific alliance and association of a pre-existing national-scale classification. NationaLly, we examined the relationship between the number of alliances and associations in a catchment and either catchment size or the number of plots per catchment by fitting Generalised Additive Models. Results： The four alliances and five associations that were observed in the Mokihinui lower gorge arepresent in the region but limited locally. One association was narrowly distributed nationally, but is the mostfrequent association in the Mokihinui lower gorge; inundation may have consequences of national importance to its long-term persistence. That the Mokihinui lower gorge area had nearly twice as many plots that could not be assigned to pre- existing alliances and associations than either the Mokihinui upper or the Karamea lower gorges and proportionally more than the national dataset emphasises the compositional distinctiveness of this gorge. These outlier plots in the Mokihinui lower gorge may be unsorted assemblages of species or reflect sampling bias or that native-
文摘There are 463 species of woody plant, belonging to 166 genera and 70 families in Shanxi, North China. The floristic composition types of genera and species are abundant, in which the compositions distributed in temperate zones (including North Temperate, Old World Temperate and Temperate Asia), having 62 genera, are dominant and account for 38.27% in total genera (except for Cosmopolitan), and they are major constructive or dominant species of vegetation in Shanxi. The floristic compositions of woody plants of Shanxi, Hebei, Beijing, Shandong, Henan, Jiangxi and Inner Mongolia were studied comparatively by using diversity index, principal component analysis(PCA) and groupaverage clustering, respectively. The floristic composition of Shanxi was considerably similar to that of Hebei, Beijing and Shandong because they shared a lot of genera, specially genera distributed in temperate regions, such as Rosa, Quercus, Populus, Salix, Acer, Ulmus, Pinus etc. and their ecoenvironment were considerably similar. However, the flora of Shanxi was comparatively different from that of Henan, Jiangxi and Inner Mongolia by reason that there were distinct differences among their ecogeographic conditions, floristic compositions and constructive or dominant species of dominant vegetation types.
