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Cluster Analysis of Chinese Pumpkin Inbred Lines 被引量:7
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作者 杜晓华 李小梅 李新峥 《Agricultural Science & Technology》 CAS 2008年第4期104-107,共4页
A cluster analysis was carried out based on Euclidean genetic distances through UPGMA method in Chinese pumpkin inbred lines.7 important agronomic traits of 46 Chinese pumpkin inbred lines were investigated.The result... A cluster analysis was carried out based on Euclidean genetic distances through UPGMA method in Chinese pumpkin inbred lines.7 important agronomic traits of 46 Chinese pumpkin inbred lines were investigated.The result indicated that 46 pumpkin inbred lines were clustered into 4 groups and the inter-groups distances was larger than that in intra-group.The genetic distances of parents were related to F1 performance and the results of cluster would increase effectiveness in the Chinese pumpkin crossing breeding. 展开更多
关键词 CHINESE PUMPKIN INBRED lineS cluster
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A cluster line approach to finding new Fe-B-Y-Nb-Zr bulk metallic glasses
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作者 Nigel Pemberton-Pigott 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2007年第S1期26-30,共5页
The glass forming ability of the [(Fe12/13Y1/13)100?xBx]96Nb2Zr2 (x=9–26) system was investigated using a series of cluster lines. Three types of clusters, an icosahedron (Fe12Y), a capped Archimedes anti-prism (Fe8B... The glass forming ability of the [(Fe12/13Y1/13)100?xBx]96Nb2Zr2 (x=9–26) system was investigated using a series of cluster lines. Three types of clusters, an icosahedron (Fe12Y), a capped Archimedes anti-prism (Fe8B3) and a capped trigonal prism (Fe9B), as well as a binary eutectic (Fe83B17) were considered. Bulk glassy alloy rods of 3 mm in diameter were synthesized using a copper mold suction-casting method. The glass transition temperature was observed for all samples in the boron range of 15.9at%-25.7at%, with the alloy at 15.9at% of boron having the best thermal properties. The ferrous-based bulk metallic glasses (BMG) obtained have high reduced glass transition temperatures with the maximum reaching 0.63 and large supercooled liquid regions with the maximum reaching 111 K. Magnetic testing revealed a large value of coercive force and remanent magnetization, being 11 kA/m and 0.1 T, re- spectively. 展开更多
关键词 bulk metallic glasses Fe-B-Y-Nb-Zr alloys composition design cluster line
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An on-line scaling method for improving scalability of a database cluster
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作者 JANG Yong ll LEE Chung ho +1 位作者 LEE Jae dong BAE Hae young 《重庆邮电学院学报(自然科学版)》 2004年第5期71-77,共7页
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on line scaling without interrupting service. To support more client’s queries... The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on line scaling without interrupting service. To support more client’s queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on line scaling method. Our method improves the existing on line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e., we decrease the number of data copy by reusing the backup data. Also, our on line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time. 展开更多
关键词 数据库串 在线缩放方法 可量测性 改进方法
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Document Clustering with Evolutionary Systems through Straight-Line Programs “<i>slp</i>”
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作者 José Luis Castillo Sequera José Raúl Fernández del Castillo Diez León Gonzalez Sotos 《Journal of Intelligent Learning Systems and Applications》 2012年第4期303-318,共16页
In this paper, we show a clustering method supported on evolutionary algorithms with the paradigm of linear genetic programming. “The Straight-Line Programs (slp)”, which uses a data structure which will be useful t... In this paper, we show a clustering method supported on evolutionary algorithms with the paradigm of linear genetic programming. “The Straight-Line Programs (slp)”, which uses a data structure which will be useful to represent collections of documents. This data structure can be seen as a linear representation of programs, as well as representations in the form of graphs. It has been used as a theoretical model in Computer Algebra, and our purpose is to reuse it in a completely different context. In this case, we apply it to the field of grouping library collections through evolutionary algorithms. We show its efficiency with experimental data we got from traditional library collections. 展开更多
关键词 clustering Genetic Algorithm Data Mining STRAIGHT line PROGRAMS
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Rigidity Symmetry Line for Thermodynamic Fluid Equations-of-State
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作者 Leslie V. Woodcock 《Journal of Modern Physics》 2024年第5期613-633,共21页
We report progress towards a modern scientific description of thermodynamic properties of fluids following the discovery (in 2012) of a coexisting critical density hiatus and a supercritical mesophase defined by perco... We report progress towards a modern scientific description of thermodynamic properties of fluids following the discovery (in 2012) of a coexisting critical density hiatus and a supercritical mesophase defined by percolation transitions. The state functions density ρ(p,T), and Gibbs energy G(p,T), of fluids, e.g. CO<sub>2</sub>, H<sub>2</sub>O and argon exhibit a symmetry characterised by the rigidity, ω = (dp/dρ)<sub>T</sub>, between gaseous and liquid states along any isotherm from critical (T<sub>c</sub>) to Boyle (T<sub>B</sub>) temperatures, on either side of the supercritical mesophase. Here, using experimental data for fluid argon, we investigate the low-density cluster physics description of an ideal dilute gas that obeys Dalton’s partial pressure law. Cluster expansions in powers of density relate to a supercritical liquid-phase rigidity symmetry (RS) line (ω = ρ<sub>rs</sub>(T) = RT) to gas phase virial coefficients. We show that it is continuous in all derivatives, linear within stable fluid phase, and relates analytically to the Boyle-work line (BW) (w = (p/ρ)<sub>T</sub> = RT), and to percolation lines of gas (PB) and liquid (PA) phases by: ρ<sub>BW</sub>(T) = 2ρ<sub>PA</sub>(T) = 3ρ<sub>PB</sub>(T) = 3ρ<sub>RS</sub>(T)/2 for T T<sub>B</sub>. These simple relationships arise, because the higher virial coefficients (b<sub>n</sub>, n ≥ 4) cancel due to clustering equilibria, or become negligible at all temperatures (0 T T<sub>B</sub>)<sub> </sub>within the gas phase. The Boyle-work line (p/ρ<sub>BW</sub>)<sub>T</sub> is related exactly at lower densities as T → T<sub>B</sub>, and accurately for liquid densities, by ρ<sub>BW</sub>(T) = −(b<sub>2</sub>/b<sub>3</sub>)<sub>T</sub>. The RS line, ω(T) = RT, defines a new liquid-density ground-state physical constant (ρ<sub>RS</sub>(0) = (2/3)ρ<sub>BW</sub>(0) for argon). Given the gas-liquid rigidity symmetry, the entire thermodynamic state functions below T<sub>B</sub> are obtainable from b<sub>2</sub>(T). A BW-line ground-state crystal density ρ<sub>BW</sub>(0) can be defined by the pair potential minimum. The Ar<sub>2</sub> pair potential, ∅ij</sub>(r<sub>ij</sub>) determines b<sub>2</sub>(T) analytically for all T. This report, therefore, advances the salient objective of liquid-state theory: an argon p(ρ,T) Equation-of-state is obtained from ∅<sub>ij</sub>(r<sub>ij</sub>) for all fluid states, without any adjustable parameters. 展开更多
关键词 Liquid-State Theory cluster Physics Percolation lines Fluid Thermodynamics Boyle line Rigidity-Symmetry line
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一次暴雨过程中极端短时强降水诊断和中尺度分析
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作者 隋沆锐 《科学技术创新》 2025年第1期13-16,共4页
【目的】对于此次极端暴雨过程进行综合分析,加深对此次极端暴雨过程的理解,为未来对此类极端暴雨过程的观测和预报提供科学思路与方法。【方法】利用FNL再分析资料,结合观测资料、卫星资料、数值预报产品对此次过程进行了分析。【结果... 【目的】对于此次极端暴雨过程进行综合分析,加深对此次极端暴雨过程的理解,为未来对此类极端暴雨过程的观测和预报提供科学思路与方法。【方法】利用FNL再分析资料,结合观测资料、卫星资料、数值预报产品对此次过程进行了分析。【结果】此次暴雨过程是受地面倒槽,高空冷涡,低空急流等共同影响下造成的。【结论】低空急流在此次过程中充当了良好的水汽通道,中层干侵入形成了不稳定性层结,冷暖空气对峙,上升气流明显;冷暖空气对峙激发了多个中尺度对流云团,第一阶段受局地对流云团发展影响,第二阶段短时强降水中心北抬,受新形成对流云团合并发展影响,小时极端降水出现在云顶亮温梯度大值区和地面辐合线附近;地面辐合线位置是此次落区预报的关键,对于短时强降水导致的暴雨,要特别重视冷空气对暴雨的触发和增幅作用。 展开更多
关键词 暴雨 中尺度对流云团 地面辐合线
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Cluster-based composition rules for ternary alloy systems 被引量:1
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作者 Chuang Dong1, 2), Qing Wang1), Weirong Chen1), Qingyu Zhang1), Jianbing Qiang1), and Yingmin Wang1) 1) State Key Laboratory of Materials Modification, Dalian University of Technology, Dalian 116024, China 2) International Center for Materials Physics, Chinese Academy of Sciences, Shenyang 110016, China 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2007年第S1期1-3,共3页
The cluster-based composition rule in ternary alloy systems including quasicrystals, bulk metallic glasses, crystalline phases and Lave phases-related body-centered cubic (BCC) solid solution forming systems was summa... The cluster-based composition rule in ternary alloy systems including quasicrystals, bulk metallic glasses, crystalline phases and Lave phases-related body-centered cubic (BCC) solid solution forming systems was summarized. The so-called cluster line in a ternary phase diagram refers to a straight composition line linking a specific binary cluster to the third element. The compo- sition ranges of quasicrystals and bulk metallic glasses can be determined by the direct use of cluster lines, where two cluster lines intersect at the optimum phase forming composition. Furthermore, the alloys on the cluster line in Laves phase-related BCC solid solution alloy systems have larger hydrogen storage capacities. 展开更多
关键词 cluster line composition design QUASICRYSTALS bulk metallic glasses hydrogen storage alloys
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Line profile studies of hydrodynamical models of cometary compact H II regions
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作者 Feng-Yao Zhu Qing-Feng Zhu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2015年第6期828-848,共21页
We simulate the evolution of cometary H II regions based on several champagne flow models and bow shock models, and calculate the profiles of the [Ne II] fine-structure line at 12.81 μm, the H30α recombination line ... We simulate the evolution of cometary H II regions based on several champagne flow models and bow shock models, and calculate the profiles of the [Ne II] fine-structure line at 12.81 μm, the H30α recombination line and the [Ne III] finestructure line at 15.55 μm for these models at different inclinations of 0°, 30° and 60°. We find that the profiles in the bow shock models are generally different from those in the champagne flow models, but the profiles in the bow shock models with lower stellar velocity (≤ 5 km s^-1) are similar to those in the champagne flow models. In champagne flow models, both the velocity of peak flux and the flux weighted central velocities of all three lines point outward from molecular clouds. In bow shock models, the directions of these velocities depend on the speed of stars. The central velocities of these lines are consistent with the stellar motion in the high stellar speed cases, but they are opposite directions from the stellar motion in the low speed cases. We notice that the line profiles from the slit along the symmetrical axis of the projected 2D image of these models are useful for distinguishing bow shock models from champagne flow models. It is also confirmed by the calculation that the flux weighted central velocity and the line luminosity of the [Ne III] line can be estimated from the [Ne II] line and the H30α line. 展开更多
关键词 H II regions -- ISM kinematics and dynamics clusters -- line profiles
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Sonar Image Detection Algorithm Based on Two-Phase Manifold Partner Clustering 被引量:1
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作者 Xingmei Wang Zhipeng Liu +1 位作者 Jianchuang Sun Shu Liu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2015年第4期105-114,共10页
According to the characteristics of sonar image data with manifold feature,the sonar image detection method based on two-phase manifold partner clustering algorithm is proposed. Firstly,K-means block clustering based ... According to the characteristics of sonar image data with manifold feature,the sonar image detection method based on two-phase manifold partner clustering algorithm is proposed. Firstly,K-means block clustering based on euclidean distance is proposed to reduce the data set. Mean value,standard deviation,and gray minimum value are considered as three features based on the relatinship between clustering model and data structure. Then K-means clustering algorithm based on manifold distance is utilized clustering again on the reduced data set to improve the detection efficiency. In K-means clustering algorithm based on manifold distance,line segment length on the manifold is analyzed,and a new power function line segment length is proposed to decrease the computational complexity. In order to quickly calculate the manifold distance,new allsource shortest path as the pretreatment of efficient algorithm is proposed. Based on this,the spatial feature of the image block is added in the three features to get the final precise partner clustering algorithm. The comparison with the other typical clustering algorithms demonstrates that the proposed algorithm gets good detection result. And it has better adaptability by experiments of the different real sonar images. 展开更多
关键词 SONAR image K-means clusterING MANIFOLD distance line SEGMENT length
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Chlorophyll Concentration and Morphological Diversity in Corn Lines at Different Vegetative Stages
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作者 Mariano Mendoza Elos Gilberto Rodríguez Pérez +7 位作者 Francisco Cervantes Ortíz Luis Patricio Guevara Acevedo Enrique Andrio Enríquez Ma. Del Carmen Ojeda Zacarías Isabel Presa Figuereo Sergio Alfredo Rodríguez Herrera José Antonio Rangel Lucio José Guadalupe Rivera Reyes 《American Journal of Plant Sciences》 2016年第7期1067-1076,共10页
The objective of this study was to assess the chlorophyll content of corn lines at different vegetative stages and the diversity between them. The study was conducted in the experimental field of the Roque Institute o... The objective of this study was to assess the chlorophyll content of corn lines at different vegetative stages and the diversity between them. The study was conducted in the experimental field of the Roque Institute of Technology (ITR) located in Roque, Celaya, Guanajuato, Mexico. We used 32 corn lines from CIMMYT and four lines from the breeding program of the ITR. The evaluation was conducted in the spring-summer cycle of 2014 at two planting dates. We used a completely randomized block design with three replications. The experimental unit consisted of two rows of five linear meters with a distance of 0.75 meters between rows. Chlorophyll was measured at six different stages: V6, VT, R3, R4, R5 and MF. The agronomic variables recorded were: PH, CH, LAC, LBC, FF, MF, PM, CC, CL, DC, RC, KR and GY. The results of the analysis of variance showed significant differences between lines, dates and their interaction. On average, 18 lines were found with chlorophyll concentrations above 51 SPAD units in the two environments. This indicated that these materials had a high potential for field performance. Using cluster analysis UPGMA method, we identified seven groups for chlorophyll and eight groups for agronomic characteristics for a breeding program. The groups were associated to the homogeneous characteristics of each variable. 展开更多
关键词 Chlorophyll Content Phenological Stages clusters and Corn lines
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Atomic epn(ep) Spin Models and Spectral Lines
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作者 Daekyoum Kim Baik-Hyon Ha 《American Journal of Analytical Chemistry》 2015年第13期1030-1037,共8页
We confirmed that how many kinds of epn spins the atoms have by calculating heat capacity of metals according to energy levels in the previous reference. To know more the spin models of epn of hydrogen and helium are ... We confirmed that how many kinds of epn spins the atoms have by calculating heat capacity of metals according to energy levels in the previous reference. To know more the spin models of epn of hydrogen and helium are imagined and their line spectra are counted. And the explanation of interference is discussed. Gas atoms make line spectra by optical interference. Solid atoms make them by exciting the lowest epns of their cluster first. They all make s, p energy orbit. One axis is composed of two epns. 1s or 2s of atoms except for lithium generally makes the symmetric axis. When each energy level is filled up by epns, these are symmetrically paired first. The atoms which fit the number of line spectra correctly by optical interference are hydrogen and helium. By counting the number of alignments of epns spins within the cluster, the atoms which fit the number of line spectra correctly are lithium, beryllium and phosphorus. The number of line spectra of the rest atoms which we have counted approaches the experimented numbers approximately, not correctly. 展开更多
关键词 ATOMIC Model ATOMIC cluster SPECTRAL lineS RESONANCE
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Resistance Evaluation to Sheath Blight in Transgenic Rice Lines
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作者 LIAi-hong XuXin-ping +4 位作者 DAIZheng-yuan CHENZong-xiang LIBao-jian ZHANGHong-xi PANXue-biao 《Rice science》 SCIE 2004年第3期95-100,共6页
Resistance of forty-one homozygous rice lines transformed with chitinase gene (RC24) and β-1,3 -glucanse gene β-1,3-Glu) to sheath blight was analyzed by inoculation. Among different lines, the resistance had signif... Resistance of forty-one homozygous rice lines transformed with chitinase gene (RC24) and β-1,3 -glucanse gene β-1,3-Glu) to sheath blight was analyzed by inoculation. Among different lines, the resistance had significant differences according to the result by cluster analysis. The lines could be categorized into resistant, moderately resistant, moderately susceptible and susceptible types, while 92.1% of which belonging to moderately resistant or moderately susceptible type. For different resistant or susceptible lines, the resistance to rice sheath blight was remarkable correlated with the chitinase activity of transgenic lines except resistant type lines, in which enzyme activity coded by target gene was lower than moderately resistant type. The chitinase activity of transgenic lines tested at different time after inoculation or different organs of the same plant was uniform, which suggested that the expression of chitinase gene was constitutive in nature. Check varieties chitinase activity would change at different time after inoculation and reach a peak at sometime, but it had no difference at various pans of the same plant. 展开更多
关键词 RICE ttansgenic lines sheath blight resistance cluster analysis chitinase activity
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基于稀疏编码的复杂机械振动信号盲分离方法
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作者 王金东 王畅 +3 位作者 赵海洋 李彦阳 曹威龙 黄飞虎 《噪声与振动控制》 CSCD 北大核心 2024年第1期168-173,186,共7页
复杂机械振动信号激励源较多,故源信号之间互为相关源,且较难满足统计独立特性,导致传统盲源分离方法分离效果不佳。对此,提出一种基于信号稀疏编码的机械振动信号盲分离方法。盲源分离的关键在于对混合矩阵的精确估计,然而机械振源中... 复杂机械振动信号激励源较多,故源信号之间互为相关源,且较难满足统计独立特性,导致传统盲源分离方法分离效果不佳。对此,提出一种基于信号稀疏编码的机械振动信号盲分离方法。盲源分离的关键在于对混合矩阵的精确估计,然而机械振源中相关成分的存在严重影响混合矩阵的估计。对此,首先对观测信号进行短时傅里叶变换,增加信号稀疏性;然后利用稀疏编码筛选出具备直线聚类特性的时频观测点,利用K均值(K-means)聚类法找到聚类中心;最后利用所提筛选规则找到估计的混合矩阵,重构出源信号。通过对往复压缩机故障数据的分析,验证了所提方法有效性。 展开更多
关键词 振动与波 盲源分离 相关源 稀疏编码 直线聚类 压缩机故障信号
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Comparisons of Several Similarity Coefficients for Cluster Analysis of Hot Pepper Germplasm Resources
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作者 Yu REN Guangsui YANG +2 位作者 Zhiqun ZHANG Xia KONG Junmei YIN 《Agricultural Biotechnology》 CAS 2014年第5期24-28,共5页
An appropriate genetic similarity coefficient is particularly important for accurately estimating the genetic similarity and phylogenetic relationship between individuals and evaluating the genetic diversity of popula... An appropriate genetic similarity coefficient is particularly important for accurately estimating the genetic similarity and phylogenetic relationship between individuals and evaluating the genetic diversity of populations. In this study, five genetic similarity coefficients were compared for analysis of phylogenetic relationship among 31 hot pepper inbred lines based on SRAP. The applicability of different genetic similarity coefficient was investigated by means of SRAP data of hot pepper inbred lines. According to the experimental results, the variation ranges of Nei & Li, Jaceard, Sorensen, Simple matching and Yule coefficients were 0. 598 - 0. 973, 0. 427 - 0. 947, 0. 598 - 0. 973, 0.427 - 0. 947 and 0. 133 - 0. 997, respectively. Results of cluster analysis based on different similarity coefficients varied greatly. To be specific, clustering results based on Nei & Li, Jaccard and Sorensen coefficients were consistent; clustering with Simple matching and Yule coef ficients led to consistent classification of category in different order and slightly different classification of subcategory. Comprehensively comparing the results of cluster analysis and the dendrograms of hot pepper inbred lines, Yule coefficient is suitable for SRAP analysis of hot pepper. 展开更多
关键词 Hot pepper Inbred lines SRAP Genetic similarity coefficient cluster analysis
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Genetic Diversity among Parents of Hybrid Rice Based on Cluster Analysis of Morphological Traits and Simple Sequence Repeat Markers 被引量:3
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作者 WANG Sheng-jun Lu Zuo-mei WAN Jian-min 《Rice science》 SCIE 2006年第3期155-160,共6页
The genetic diversity of 41 parental lines popularized in commercial hybrid rice production in China was studied by using cluster analysis of morphological traits and simple sequence repeat (SSR) markers. Forty-one ... The genetic diversity of 41 parental lines popularized in commercial hybrid rice production in China was studied by using cluster analysis of morphological traits and simple sequence repeat (SSR) markers. Forty-one entries were assigned into two clusters (i.e. early or medium-maturing cluster; medium or late-maturing cluster) and further assigned into six sub-clusters based on morphological trait cluster analysis, The early or medium-maturing cluster was composed of 15 maintainer lines, four early-maturing restorer lines and two thermo-sensitive genic male sterile lines, and the medium or late-maturing cluster included 16 restorer lines and 4 medium or late-maturing maintainer lines. Moreover, the SSR cluster analysis classified 41 entries into two groups (i.e, maintainer line group and restorer line group) and seven sub-groups. The maintainer line group consisted of all 19 maintainer lines, two thermo-sensitive genic male sterile lines, while the restorer line group was composed of all 20 restorer lines. The SSR analysis fitted better with the pedigree information. From the views on hybrid rice breeding, the results suggested that SSR analysis might be a better method to study the diversity of parental lines in indica hybrid rice. 展开更多
关键词 parental lines hybrid rice morphological trait simple sequence repeats clustering analysis genetic diversity PEDIGREE
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High Dimensional Cluster Analysis Using Path Lengths
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作者 Kevin Mcilhany Stephen Wiggins 《Journal of Data Analysis and Information Processing》 2018年第3期93-125,共33页
A hierarchical scheme for clustering data is presented which applies to spaces with a high number of dimensions (). The data set is first reduced to a smaller set of partitions (multi-dimensional bins). Multiple clust... A hierarchical scheme for clustering data is presented which applies to spaces with a high number of dimensions (). The data set is first reduced to a smaller set of partitions (multi-dimensional bins). Multiple clustering techniques are used, including spectral clustering;however, new techniques are also introduced based on the path length between partitions that are connected to one another. A Line-of-Sight algorithm is also developed for clustering. A test bank of 12 data sets with varying properties is used to expose the strengths and weaknesses of each technique. Finally, a robust clustering technique is discussed based on reaching a consensus among the multiple approaches, overcoming the weaknesses found individually. 展开更多
关键词 clusterING PATH LENGTH CONSENSUS N-Dimensional line of SIGHT
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物流园区业务整合视角下物流业集群升级研究
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作者 龚爱清 张立国 《对外经贸》 2024年第7期67-69,112,共4页
物流园区是物流业集群化发展的产物,是推进物流业升级的重要载体。以物流园区为研究对象,聚焦园区之间的业务整合问题,从专线运输、仓储配送和货运订单三种业务整合视角,分析归纳了物流园区业务整合推进物流业集群升级的方式。其中,专... 物流园区是物流业集群化发展的产物,是推进物流业升级的重要载体。以物流园区为研究对象,聚焦园区之间的业务整合问题,从专线运输、仓储配送和货运订单三种业务整合视角,分析归纳了物流园区业务整合推进物流业集群升级的方式。其中,专线运输视角归纳为主体企业整合和会员制整合两种方式,仓储配送视角归纳为物流业务整合和设施设备整合两种方式,货运订单视角归纳为横向整合和纵向整合两种方式。在介绍每种方式时,通过物流园区案例研究和探讨,归纳总结了我国目前各地以物流园区业务整合推进物流业集群升级的一些经验和做法。业务整合是近年来物流园区发展的重要方向,对推进物流业升级具有一定的借鉴价值。 展开更多
关键词 物流园区 物流业集群升级 专线运输 仓储配送 货运订单
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基于GT双标图对小麦新品系的分类评价
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作者 孙宪印 牟秋焕 +9 位作者 米勇 吕广德 亓晓蕾 孙盈盈 尹逊栋 王瑞霞 吴科 钱兆国 赵岩 高明刚 《中国农业科技导报》 CAS CSCD 北大核心 2024年第7期14-24,共11页
为了从产量、品质方面准确评价旱肥地试验小麦新品系,以2020—2021年连续2年参加国家黄淮冬麦区旱地组多点比较试验的26份新品系为材料,应用多元统计方法分析了大田条件下2年间产量和品质性状的变化。结果表明:26份品系的产量和品质性状... 为了从产量、品质方面准确评价旱肥地试验小麦新品系,以2020—2021年连续2年参加国家黄淮冬麦区旱地组多点比较试验的26份新品系为材料,应用多元统计方法分析了大田条件下2年间产量和品质性状的变化。结果表明:26份品系的产量和品质性状2年变异系数分别为2.0%~74.2%和2.1%~95.1%,变异较大,变异系数大小顺序依次为稳定时间>湿面筋含量>蛋白质含量>吸水率=单位面积产量>容重;相关分析表明,2年产量与品质性状存在负相关关系,稳定时间均与蛋白质含量、吸水量正相关,稳定时间与产量负相关,其中稳定时间与蛋白质含量相关系数均较高。在相关分析的基础上,采用聚类分析方法将2年中26份小麦参试品系聚为4类,并在主成分品种、性状(genotype by trait,GT)双标图(biplot)和聚类图中进行展示,聚类结果与新品系的实际表现一致,其中‘泰科麦4835’‘洛旱35’‘农大162’‘山农611436’连续2年划为同一类型,表现为产量较高、品质优良。该研究结果可为参试新品系的合理评价和推广应用提供理论依据。 展开更多
关键词 小麦新品系 主成分分析 GT双标图 聚类分析 产量 品质性状
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50份加工型辣椒DH系苗期耐低温弱光综合评价
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作者 王春萍 李怡斐 +5 位作者 张世才 杨小苗 段敏杰 雷开荣 黄启中 黄任中 《中国蔬菜》 北大核心 2024年第6期48-54,共7页
以前期利用花药培养技术创制的50份加工型辣椒DH系为试验材料,以SPAD值、F_(v)/F_(m)、根系直径、茎叶干质量、根系干质量、整株干质量和根冠比7个指标的耐低温弱光指数为评价指标,采用模糊隶属函数和聚类分析法对其进行耐低温弱光综合... 以前期利用花药培养技术创制的50份加工型辣椒DH系为试验材料,以SPAD值、F_(v)/F_(m)、根系直径、茎叶干质量、根系干质量、整株干质量和根冠比7个指标的耐低温弱光指数为评价指标,采用模糊隶属函数和聚类分析法对其进行耐低温弱光综合评价。结果表明:50份DH系的耐低温弱光模糊隶属函数综合指数范围在0.20~0.76之间,聚类分析可将其分为两大类,根据耐低温弱光指数特点和模糊隶属函数综合指数可确定第Ⅱ类有7份DH系为耐低温弱光材料,即H201605-8、H201604-4-1、H201612-4-1、H201605-7、H201612-4、H201605-34和H201604-18。50份加工型辣椒DH系间耐低温弱光性差异较大,可作为相关机理研究的试验材料;筛选出的7份耐低温弱光DH系为培育适合设施栽培的优良辣椒新品种提供了材料基础,也为定向培育抗非生物逆境辣椒种质新材料提供了参考。 展开更多
关键词 辣椒 DH系 低温弱光 模糊隶属函数分析 聚类分析
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基于二阶聚类和鲁棒性随机分割森林算法的低压台区线损异常辨识 被引量:4
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作者 刘雄 夏向阳 +4 位作者 刘定国 胡军华 黄瑞 李泽文 史子轶 《现代电力》 北大核心 2024年第3期441-447,共7页
为精准识别台区的线损异常,保证配电网经济、稳定运行,针对台区线损的异常情况,提出一种基于二阶聚类和鲁棒性随机分割森林(robust random cut forest,RRCF)算法的台区线损异常检测方法。首先,运用二阶聚类将台区不同的运行工况进行聚类... 为精准识别台区的线损异常,保证配电网经济、稳定运行,针对台区线损的异常情况,提出一种基于二阶聚类和鲁棒性随机分割森林(robust random cut forest,RRCF)算法的台区线损异常检测方法。首先,运用二阶聚类将台区不同的运行工况进行聚类,将相同工况的线损节点归并,然后将各类工况的节点线损数据导入RRCF算法中分析,通过删除和插入样本节点,并对插入节点后评判模型的复杂度进行计算,得到线损异常节点的评分值,进一步找出线损异常的节点。最终,通过有关实例验证所提方法的准确性与有效性。 展开更多
关键词 低压台区 二阶聚类 RRCF算法 线损异常
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