Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 8

年份

2015 1

2014 1

2013 1

2011 2

2009 2

2003 1

关键词

原位统计分布分析 2

统计偏析度 2

统计符合度 2

中国近30 多年的地震预报统计 1

原位统计分布分析表征技术 1

地震 1

地震预测 1

均匀度 1

夹杂 1

夹杂物 1

模具钢 1

疏松度 1

质量控制 1

连铸钢坯 1

铌 1

高温合金压气机盘 1

展开︾

检索范围：

排序：展示方式：

热作模具钢的原位统计分布分析

王海舟,李美玲,张秀鑫,吴超

《中国工程科学》 2009年第11卷第10期页码 39-47

摘要：

采用原位统计分布分析技术对不同来源的模具钢进行解析，获得了模具钢坯横剖面较大尺度范围内各化学组成的位置分布、状态分布、含量分布的一系列新信息；定量表征了不同来源模具钢的最大偏析度、统计偏析度、统计符合度、统计致密度、统计疏松度、夹杂物种类和含量以及粒度统计分布等参数的差异性，可用于不同来源模具钢质量差异解析的参考。

关键词：原位统计分布分析模具钢统计偏析度统计符合度夹杂

HTML PDF 收藏

高温合金压气机盘锻件纵断面中铌分布的原位统计分布分析表征

王海舟,李美玲,庄景云

《中国工程科学》 2011年第13卷第10期页码 19-27

摘要：

采用原位统计分布分析表征技术系统研究了GH169高温合金压气机盘纵断面不同部位铌分布的规律。以所得到的与样品原位置相对应的数以万计原始信号系统解析为基础，进而获得压气机盘锻件的纵断面不同部位铌的定量统计分布信息以及加工工艺过程中铌的迁移规律。准确计算判定了盘纵断面不同部位铌的最大偏析度，提出了95 %置信度时中位值置信扩展率,即统计偏析度（S）新参数，用以表征铌在压气机盘中分布的均匀度；提出了所有数据在特定含量区间（C₀±R）的频度（权重）比率，即统计符合度（F）新参数，用以表征预设质量控制区间铌含量的一致性的概率。采用原位统计分布分析的表征方法，准确定量地评定了高温合金压气机盘件纵断面不同部位铌的分布均匀度和符合度，为加工后盘件的质量控制评估提供了参考。

关键词：原位统计分布分析表征技术高温合金压气机盘铌统计偏析度统计符合度质量控制

HTML PDF 收藏

连铸钢坯质量的原位统计分布分析研究

王海舟,李美玲,陈吉文,吴超

《中国工程科学》 2003年第5卷第10期页码 34-42

摘要：

采用原位统计分布分析技术得到与样品原位置相对应的数以万计原始信号并对其进行系统解析，实现不同质量连铸钢坯试样的疏松度、均匀度以及夹杂物含量的定量表征。准确计算了连铸钢坯试样疏松度、碳元素的最大偏析度。提出铸坯各原位置成分含量的权重比率方法用以表征材料的均匀度，并提供了统计分布允许差范围内（C₀±R）所占权重比率以及权重比率为95%置信度时，中位值置信扩展率（K）等2种判断模式。该方法以测量信息的原始性、原位性及统计性为特征，反映了连铸钢坯较大尺度范围内各化学组成及其形态的定量统计分布规律。采用上述方法可以合理解释连铸钢坯之间的质量差异性，可作为连铸钢坯质量的判断依据。

关键词：原位统计分布分析连铸钢坯疏松度均匀度夹杂物

HTML PDF 收藏

Analysis on the distinguishing features of traditional Chinese therapeutics and related statistical issues

Jingqing Hu, Jie Qiao, Deying Kang, Baoyan Liu

《医学前沿（英文）》 2011年第5卷第2期页码 203-207 doi: 10.1007/s11684-011-0138-6

摘要： Traditional Chinese medicine (TCM) is one of the rarely existing ancient traditional medicines that hold systematic theories as well as preventative and therapeutic methods for diseases in practice. From the 1950s, such research methods as mathematics, statistics, and data mining (DM) have been gradually introduced to TCM studies, making it more scientific. Meanwhile, the distinct features of TCM theories and diagnostic-model have constantly challenged the methodology of statistics. This paper introduces the following scientific features of traditional Chinese therapeutics: 1) its goal is to balance the functions and conditions of human body; 2) it emphasizes on holism and individualization; 3) it stresses the longitudinal regulation and evaluation mode, which is a circle of syndrome diagnosis, treatment and evaluation; 4) the interventions of TCM are abundant, compound and natural; and 5) humanistic thought is everywhere. Some statistical problems are raised based on these features. First, complex statistical methods that can analyze subjective indexes and latent variables, multidimensional and multistage data, non-equilibrium designed studies, and longitudinal data are required. Second, comprehensive evaluation on multiple-target mechanism has been brought in by combination treatment. Third, there is a need to analyze how humanity and related cultural factors may influence the effect of interventions. Thus, promoting implemented studies of statistics as well as carrying out the TCM scientific propositions have become the common expectations of both TCM and modern medicine.

关键词： traditional Chinese therapeutics feature statistic

HTML PDF 收藏

Changes in hourly precipitation may explain the sharp reduction of discharge in the middle reach of the Yellow River after 2000

Lin LUO, Zhongjing WANG

《环境科学与工程前沿（英文）》 2013年第7卷第5期页码 756-768 doi: 10.1007/s11783-013-0563-7

摘要： The Hekou-Longmen reach, together with local floods, is the main source area for coarse sedimentations into the Yellow River. When total rainfall slightly increased in the area, discharge dramatically decreased by 40%–70% after the year of 2000, and attracting extensive attention in the context of global climate change. High temporal resolution precipitation (timescales between 1 and 4 h) data from the June to September period from 270 rain gauges over the past three decades was mined in order to help explain the phenomenon. Each rainfall event was classified as light/moderate rain, large rain, heavy rain or rainstorm by the event’s rainfall amount, and further classified as low intensity rain, medium intensity rain and high intensity rain by the event’s rainfall intensity. The Mann-Kendall trend test was applied to detect the presence and significance of monotonic trends, and to find the change points in the mean and variance of the precipitation characteristics series, including the amount, intensity, frequency and duration of each rainfall category. Results show that although the total amount of precipitation has slightly increased, the average rainfall intensity has significantly decreased. The larger change happened in light/moderate rain events and low/medium intensity rain events, and the intensity changes have a great extent occurred around the threshold of Non-Runoff Rainfall regime, which was proposed for the approximate calculation of initial losses. Changes in rainfall distribution between different classes of the Runoff Rainfall regime in the 2000s could lead to 0.9 mm less runoff depth (17.3% of the total reduction) than the 1980–1999 period. The study indicates that changes in hourly precipitation may be responsible for the sharp reduction of discharge.

关键词： precipitation intensity Mann-Kendall rank statistic spatial and temporal distribution climatic change

HTML PDF 收藏

我国地震预测成绩的回顾与统计

高建国

《中国工程科学》 2009年第11卷第6期页码 129-131

摘要：

地震预测预报的难度大，但并非了无痕迹或不可知，我国每次较大的地震都有案例总结。统计表明，近４０年来，有７７次地震在发生前均有中期、短期甚至临震预测，不能因为汶川地震预测的失败，就全面抹杀中国的地震预报成绩，即我国的地震预测成绩是应予肯定的，汶川地震也并非是无前兆的“怪震”。

关键词：地震地震预测中国近30 多年的地震预报统计

HTML PDF 收藏

Resampling methods for particle filtering: identical distribution, a new method, and comparable study

Tian-cheng LI,Gabriel VILLARRUBIA,Shu-dong SUN,Juan M. CORCHADO,Javier BAJO

《信息与电子工程前沿（英文）》 2015年第16卷第11期页码 969-984 doi: 10.1631/FITEE.1500199

摘要： Resampling is a critical procedure that is of both theoretical and practical significance for efficient implementation of the particle filter. To gain an insight of the resampling process and the filter, this paper contributes in three further respects as a sequel to the tutorial (Li et al., 2015). First, identical distribution (ID) is established as a general principle for the resampling design, which requires the distribution of particles before and after resampling to be statistically identical. Three consistent metrics including the (symmetrical) Kullback-Leibler divergence, Kolmogorov-Smirnov statistic, and the sampling variance are introduced for assessment of the ID attribute of resampling, and a corresponding, qualitative ID analysis of representative resampling methods is given. Second, a novel resampling scheme that obtains the optimal ID attribute in the sense of minimum sampling variance is proposed. Third, more than a dozen typical resampling methods are compared via simulations in terms of sample size variation, sampling variance, computing speed, and estimation accuracy. These form a more comprehensive understanding of the algorithm, providing solid guidelines for either selection of existing resampling methods or new implementations.

关键词： Particle filter Resampling Kullback-Leibler divergence Kolmogorov-Smirnov statistic

HTML PDF 收藏

Evaluation of the ecological status with benthic indices in the coastal system: the case of Bohai Bay (China)

Wenqian CAI,Wei MENG,Lusan LIU,Kuixuan LIN

《环境科学与工程前沿（英文）》 2014年第8卷第5期页码 737-746 doi: 10.1007/s11783-013-0617-x

摘要： Based on biologic and environmental materials collected from coastal areas of Bohai Bay (China) in April, 2008, three biotic indices (AZTI’s Marine Biotic Index (AMBI), Shannon–Wiener Index and -statistic) were applied together to evaluate the ecological status of the sampling area. The results showed a clear spatial gradient from a worse ecological status in the near-shore areas (especially around Haihe and Jiyun River Estuaries) to a better status in the offshore areas. While all the three indices could assist decision makers in visualizing spatial changes of organic pollutants in Bohai Bay, two indices, i.e., AMBI and Shannon-Wiener index, were effective in distinguishing sites from Haihe River Estuary, Jiyun River Estuary and other area. However, -statistic can’t tell the differences between estuaries and other area. It would be explained that organic pollutants and/or other environmental stresses in Bohai Bay were not strong enough to reduce the size of macrozoobenthos, which may cause both of the abundance and biomass curves crossed. To our knowledge, this is the first time that several benthic indices were used to assess the benthic ecological status in Bohai Bay, which gave the similar results. Furthermore, there is indication that the ecological status is related to excess input of wastewater along main rivers and outlets. In a word, AMBI, Shannon–Wiener Index and -statistic could be able to assess the benthic ecological status of Bohai Bay under the organic pollutants pressure.

关键词： AZTI’s Marine Biotic Index Shannon-Wiener Index W-statistic ecological status coastal system Bohai Bay (China)