Quantitative descriptions of geochemical patterns and providing geochemical anomaly map are important in applied geochemistry. Several statistical methodologies are presented in order to identify and separate geochemi...Quantitative descriptions of geochemical patterns and providing geochemical anomaly map are important in applied geochemistry. Several statistical methodologies are presented in order to identify and separate geochemical anomalies. The U-statistic method is one of the most important structural methods and is a kind of weighted mean that surrounding points of samples are considered in U value determination. However, it is able to separate the different anomalies based on only one variable. The main aim of the presented study is development of this method in a multivariate mode. For this purpose, U-statistic method should be combined with a multivariate method which devotes a new value to each sample based on several variables. Therefore, at the first step, the optimum p is calculated in p-norm distance and then U-statistic method is applied on p-norm distance values of the samples because p-norm distance is calculated based on several variables. This method is a combination of efficient U-statistic method and p-norm distance and is used for the first time in this research. Results show that p-norm distance of p=2(Euclidean distance) in the case of a fact that Au and As can be considered optimized p-norm distance with the lowest error. The samples indicated by the combination of these methods as anomalous are more regular, less dispersed and more accurate than using just the U-statistic or other nonstructural methods such as Mahalanobis distance. Also it was observed that the combination results are closely associated with the defined Au ore indication within the studied area. Finally, univariate and bivariate geochemical anomaly maps are provided for Au and As, which have been respectively prepared using U-statistic and its combination with Euclidean distance method.展开更多
利用已搜集的180份菜用豌豆材料进行核心种质构建策略研究。分别对所有种质材料进行单株荚数、每荚粒数、荚长、荚宽、荚厚、百荚鲜质量、百粒鲜质量及产量等性状进行调查,结果表明,搜集的材料具有丰富的遗传多样性。利用上述数据,采用...利用已搜集的180份菜用豌豆材料进行核心种质构建策略研究。分别对所有种质材料进行单株荚数、每荚粒数、荚长、荚宽、荚厚、百荚鲜质量、百粒鲜质量及产量等性状进行调查,结果表明,搜集的材料具有丰富的遗传多样性。利用上述数据,采用最小距离逐步取样(minimum distance stepwise sampling,LDSS)法,分别选择4种遗传距离、8种取样比例进行核心种质构建策略研究,并采用极差符合率(coincidence rate of range,CR)和变异系数变化率(variable rate of coefficient of variation,VR)2个参数对构建策略进行评价;同时,利用主成分分析法和聚类分析法对构建的核心种质代表性进行鉴定。结果表明,采用LDSS法构建菜用豌豆核心种质的最佳遗传距离为欧式距离,最佳取样比例为25%。该构建策略将为菜用豌豆核心种质构建与高效利用奠定基础。展开更多
针对变压器故障诊断中油溶气体技术的改良三比值法存在故障区域边界值判断模糊的问题,在分析改良三比值法的基础上,以欧式距离来表征隶属每种故障概率大小的形式,建立了不同故障下的基本信任分配函数(BBA)诊断模型进行变压器故障诊断,...针对变压器故障诊断中油溶气体技术的改良三比值法存在故障区域边界值判断模糊的问题,在分析改良三比值法的基础上,以欧式距离来表征隶属每种故障概率大小的形式,建立了不同故障下的基本信任分配函数(BBA)诊断模型进行变压器故障诊断,并采用D-S合成规则对不同故障的BBA进行融合,实现了对多BBA模型函数重新构造以及归一表述的功能。利用该模型对长春某500 k VA变电站的变压器故障进行实例计算,并通过改良三比值法和模糊算法进行对比分析。结果表明:该诊断模型能准确、有效地对变压器的多种常见故障进行诊断;用计算隶属故障概率的形式弥补了改良三比值法边界值计算模糊的缺陷,使故障的判别更加趋于真实准确,为电力变压器故障诊断提供了一种有效的方法。展开更多
文摘Quantitative descriptions of geochemical patterns and providing geochemical anomaly map are important in applied geochemistry. Several statistical methodologies are presented in order to identify and separate geochemical anomalies. The U-statistic method is one of the most important structural methods and is a kind of weighted mean that surrounding points of samples are considered in U value determination. However, it is able to separate the different anomalies based on only one variable. The main aim of the presented study is development of this method in a multivariate mode. For this purpose, U-statistic method should be combined with a multivariate method which devotes a new value to each sample based on several variables. Therefore, at the first step, the optimum p is calculated in p-norm distance and then U-statistic method is applied on p-norm distance values of the samples because p-norm distance is calculated based on several variables. This method is a combination of efficient U-statistic method and p-norm distance and is used for the first time in this research. Results show that p-norm distance of p=2(Euclidean distance) in the case of a fact that Au and As can be considered optimized p-norm distance with the lowest error. The samples indicated by the combination of these methods as anomalous are more regular, less dispersed and more accurate than using just the U-statistic or other nonstructural methods such as Mahalanobis distance. Also it was observed that the combination results are closely associated with the defined Au ore indication within the studied area. Finally, univariate and bivariate geochemical anomaly maps are provided for Au and As, which have been respectively prepared using U-statistic and its combination with Euclidean distance method.
文摘利用已搜集的180份菜用豌豆材料进行核心种质构建策略研究。分别对所有种质材料进行单株荚数、每荚粒数、荚长、荚宽、荚厚、百荚鲜质量、百粒鲜质量及产量等性状进行调查,结果表明,搜集的材料具有丰富的遗传多样性。利用上述数据,采用最小距离逐步取样(minimum distance stepwise sampling,LDSS)法,分别选择4种遗传距离、8种取样比例进行核心种质构建策略研究,并采用极差符合率(coincidence rate of range,CR)和变异系数变化率(variable rate of coefficient of variation,VR)2个参数对构建策略进行评价;同时,利用主成分分析法和聚类分析法对构建的核心种质代表性进行鉴定。结果表明,采用LDSS法构建菜用豌豆核心种质的最佳遗传距离为欧式距离,最佳取样比例为25%。该构建策略将为菜用豌豆核心种质构建与高效利用奠定基础。
文摘针对变压器故障诊断中油溶气体技术的改良三比值法存在故障区域边界值判断模糊的问题,在分析改良三比值法的基础上,以欧式距离来表征隶属每种故障概率大小的形式,建立了不同故障下的基本信任分配函数(BBA)诊断模型进行变压器故障诊断,并采用D-S合成规则对不同故障的BBA进行融合,实现了对多BBA模型函数重新构造以及归一表述的功能。利用该模型对长春某500 k VA变电站的变压器故障进行实例计算,并通过改良三比值法和模糊算法进行对比分析。结果表明:该诊断模型能准确、有效地对变压器的多种常见故障进行诊断;用计算隶属故障概率的形式弥补了改良三比值法边界值计算模糊的缺陷,使故障的判别更加趋于真实准确,为电力变压器故障诊断提供了一种有效的方法。
