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Spatial and temporal analysis of beta diversity in the Barro Colorado Island forest dynamics plot, Panama 被引量:2
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作者 Pierre Legendre Richard Condit 《Forest Ecosystems》 SCIE CSCD 2019年第1期76-86,共11页
Background: Ecologists are interested in assessing the spatial and temporal variation in ecological surveys repeated over time. This paper compares the 1985 and 2015 surveys of the Barro Colorado Forest Dynamics plot(... Background: Ecologists are interested in assessing the spatial and temporal variation in ecological surveys repeated over time. This paper compares the 1985 and 2015 surveys of the Barro Colorado Forest Dynamics plot(BCI), Panama,divided into 1250(20 m × 20 m) quadrats.Methods, spatial analysis: Total beta diversity was measured as the total variance of the Hellinger-transformed community data throughout the BCI plot. Total beta was partitioned into contributions of individual sites(LCBD indices), which were tested for significance and mapped.Results, spatial analysis: LCBD indices indicated the sites with exceptional community composition. In 1985,they were mostly found in the swamp habitat. In the 2015 survey, none of the swamp quadrats had significant LCBDs.What happened to the tree community in the interval?Methods, temporal analysis: The dissimilarity in community composition in each quadrat was measured between time 1(1985) and time 2(2015). Temporal Beta Indices(TBI) were computed from abundance and presence-absence data and tested for significance. TBI indices can be decomposed into B = species(or abundances-per-species) losses and C = species(or abundances-per-species) gains. B-C plots were produced; they display visually the relative importance of the loss and gain components, through time, across the sites.Results, temporal analysis: In BCI, quadrats with significant TBI indices were found in the swamp area, which is shrinking in importance due to changes to the local climate. A published habitat classification divided the BCI forest plot into six habitat zones. Graphs of the B and C components were produced for each habitat group. Group 4(the swamp) was dominated by species(and abundances-per-species) gains whereas the five other habitat groups were dominated by losses, some groups more than others.Conclusions: We identified the species that had changed the most in abundances in the swamp between T1 and T2.This analysis supported the hypothesis that the swamp is drying out and is invaded by species from the surrounding area. Analysis of the B and C components of temporal beta diversity bring us to the heart of the mechanisms of community change through time: losses(B) and gains(C) of species, losses and gains of individuals of various species. TBI analysis is especially interesting in species-rich communities where we cannot examine the changes in every species individually. 展开更多
关键词 BETA DIVERSITY B-C plotS BCI forest dynamics plot SPACE-TIME analysis Temporal BETA DIVERSITY
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Derringer desirability and kinetic plot LC-column comparison approach for MS-compatible lipopeptide analysis 被引量:1
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作者 Matthias D’Hondt Frederick Verbeke +3 位作者 Sofie Stalmans Bert Gevaert Evelien Wynendaele Bart De Spiegeleer 《Journal of Pharmaceutical Analysis》 SCIE CAS 2014年第3期173-182,共10页
Lipopeptides are currently re-emerging as an interesting subgroup in the peptide research field, having historical applications as antibacterial and antifungal agents and new potential applications as antiviral, antit... Lipopeptides are currently re-emerging as an interesting subgroup in the peptide research field, having historical applications as antibacterial and antifungal agents and new potential applications as antiviral, antitumor, immune-modulating and cell-penetrating compounds. However, due to their specific structure, chromatographic analysis often requires special buffer systems or the use of trifluoroacetic acid, limiting mass spectrometry detection. Therefore, we used a traditional aqueous/acetonitrile based gradient system, containing 0.1% (m/v) formic acid, to separate four pharmaceutically relevant lipopeptides (polymyxin B1, caspofungin, daptomycin and gramicidin A1), which were selected based upon hierarchical cluster analysis (HCA) and principal component analysis (PCA).In total, the performance of four different C18 columns, including one UPLC column, were evaluated using two parallel approaches. First, a Derringer desirability function was used, whereby six single and multiple chromatographic response values were rescaled into one overall D-value per column. Using this approach, the YMC Pack Pro C18 column was ranked as the best column for general MS-compatible lipopeptide separation. Secondly, the kinetic plot approach was used to compare the different columns at different flow rate ranges. As the optimal kinetic column performance is obtained at its maximal pressure, the length elongation factor λ(Pmax/Pexp) was used to transform the obtained experimental data (retention times and peak capacities) and construct kinetic performance limit (KPL) curves, allowing a direct visual and unbiased comparison of the selected columns, whereby the YMC Triart C18 UPLC and ACE C18 columns performed as best. Finally, differences in column performance and the (dis)advantages of both approaches are discussed. 展开更多
关键词 LIPOPEPTIDE Hierarchical cluster analysis (HCA) Principal component analysis (PCA) LC-MS Kinetic plot Derringer desirability function
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Application of SWAT99.2 to sensitivity analysis of water balance components in unique plots in a hilly region
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作者 Jun-feng Dai Jia-zhou Chen +3 位作者 Guo-an Lu Larry C. Brown Lei Gan Qin-xue Xu 《Water Science and Engineering》 EI CAS CSCD 2017年第3期209-216,共8页
Although many sensitivity analyses using the soil and water assessment tool(SWAT) in a complex watershed have been conducted, little attention has been paid to the application potential of the model in unique plots. I... Although many sensitivity analyses using the soil and water assessment tool(SWAT) in a complex watershed have been conducted, little attention has been paid to the application potential of the model in unique plots. In addition, sensitivity analysis of percolation and evapotranspiration with SWAT has seldom been undertaken. In this study, SWAT99.2 was calibrated to simulate water balance components for unique plots in Southern China from 2000 to 2001, which included surface runoff, percolation, and evapotranspiration. Twenty-one parameters classified into four categories, including meteorological conditions, topographical characteristics, soil properties, and vegetation attributes, were used for sensitivity analysis through one-at-a-time(OAT) sampling to identify the factor that contributed most to the variance in water balance components. The results were shown to be different for different plots, with parameter sensitivity indices and ranks varying for different water balance components. Water balance components in the broad-leaved forest and natural grass plots were most sensitive to meteorological conditions, less sensitive to vegetation attributes and soil properties, and least sensitive to topographical characteristics. Compared to those in the natural grass plot, water balance components in the broad-leaved forest plot demonstrated higher sensitivity to the maximum stomatal conductance(GSI) and maximum leaf area index(BLAI). 展开更多
关键词 Forest and GRASS plotS WATER balance Sensitivity analysis Soil and WATER assessment tool (SWAT) One-at-a-time (OAT) method
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Establishment of Permanent Sample Plots and Analysis of Stand Characteristics for Interior Douglas-Fir Forests
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作者 宫伟光 PeterL.Marshall 《Journal of Forestry Research》 SCIE CAS CSCD 1997年第1期23-26,共4页
In order to study the dynamics of uneven-aged stands of interior Douglas-fir, Pseudotsuga menzesii var.glouca (Mirb.) Franco in future, six permanent sample plots wer set up on the Knife Creek Block of the Alex Fraser... In order to study the dynamics of uneven-aged stands of interior Douglas-fir, Pseudotsuga menzesii var.glouca (Mirb.) Franco in future, six permanent sample plots wer set up on the Knife Creek Block of the Alex Fraser Researh Forcst of University of British Columbia. The measurements and observations for all living trees within theboundaries of a plot wer madc, including DBH(diameter at breast height), TTH(total tree height), height to lowest livingbranch, crown diameter, tree vigor, angle of lean, distance of lean, direction of lean and tree location. Based on the data,some stand characteristics of the plots were analyzed simply and preliminarily. Results showed that most of the interiortrees on the plots are ranged 10-20 cm in distribution of DBH class, and 2-6 m in distribution of rm class. Trees withdifferent fors, however, are distributed unevenly. The relationship between total tree height and diameter at breast heightfollows a quadratic distribution, Y=a+bX+cX2. 展开更多
关键词 Permanent sample plot Stand analysis DOUGLAS-FIR
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A Reinterpretation of Historic Aquifer Tests of Two Hydraulically Fractured Wells by Application of Inverse Analysis, Derivative Analysis, and Diagnostic Plots
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作者 Patrick A. Hammond Malcolm S. Field 《Journal of Water Resource and Protection》 2014年第5期481-506,共26页
Aquifer test methods have greatly improved in recent years with the advent of inverse analysis, derivative analysis, and diagnostic plots. Updated analyses of past aquifer tests allow for improved interpretations of t... Aquifer test methods have greatly improved in recent years with the advent of inverse analysis, derivative analysis, and diagnostic plots. Updated analyses of past aquifer tests allow for improved interpretations of the data to enhance the knowledge and the predictive capabilities of the flow system. This work thoroughly reanalyzes a series of pre- and post-hydraulic fracturing, single-well aquifer tests conducted in two crystalline rock wells in New Hampshire as part of an early 1970’s study. Previous analyses of the data had relied on older manual type-curve methods for predicting the possible effects of hydraulic fracturing. This work applies inverse analysis, derivative analysis, and diagnostic plots to reanalyze the 1970’s aquifer test data. Our results demonstrate that the aquifer tests were affected by changes in flow regimes, dewatering of the aquifer and discrete fractures, and changes due to well development. Increases in transmissivities are related to well development prior to hydraulic fracturing, propagation of a single, vertical fracture hydraulically connecting the two wells after stimulation and expansion of troughs of depression. After hydraulic fracturing, the estimated total yield of the individual wells increased by 2.5 times due to the hydraulic fracturing. However, the wells may be receiving water from the same source, and well interference may affect any significant increase in their combined yield. Our analyses demonstrate the value in applying inverse analysis, derivative analysis, and diagnostic plots over the conventional method of manual type-curve analysis. In addition, our improvement in the aquifer test interpretation of the 1970’s test data has implications for more reliable estimates of sustained well yields. 展开更多
关键词 Aquifer-Test analysis Inverse analysis Derivative analysis DIAGNOSTIC plotS Hydraulic FRACTURING
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Analysis of Key Features of Non-Linear Behavior Using Recurrence Plots. Case Study: Urban Pollution at Mexico City
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作者 Marco A. Aceves-Fernandez Jesus Carlos Pedraza-Ortega +3 位作者 Artemio Sotomayor-Olmedo Juan M. Ramos-Arreguín Jose Emilio Vargas-Soto Saul Tovar-Arriaga 《Journal of Environmental Protection》 2012年第9期1147-1160,共14页
The use of Recurrence plots have been extensively used in various fields. In this work, Recurrence Plots (RPs) investigates the changes in the non-linear behaviour of urban air pollution using large datasets of raw da... The use of Recurrence plots have been extensively used in various fields. In this work, Recurrence Plots (RPs) investigates the changes in the non-linear behaviour of urban air pollution using large datasets of raw data (hourly). This analysis has not been used before to extract information from large datasets for this type non-linear problem. Two different approaches have been used to tackle this problem. The first approach is to show results according to monitoring network. The second approach is to show the results by particle type. This analysis shows the feasibility of using Recurrence Analysis for pollution monitoring and control. 展开更多
关键词 RECURRENCE plot AIR Quality AIR POLLUTION Modelling ATMOSPHERIC POLLUTION RECURRENCE Quantification analysis
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Plot Analysis of The Importance of Being Ernest
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作者 郑艳红 《科教导刊》 2013年第29期181-182,共2页
Throughout Oscar Wilde’s farcical comedy,The Importance of Being Ernest,there are two story lines.The lines are both independent to each other,but are connected with each other.With the author’s thoughtful arrangeme... Throughout Oscar Wilde’s farcical comedy,The Importance of Being Ernest,there are two story lines.The lines are both independent to each other,but are connected with each other.With the author’s thoughtful arrangement and distinctive technology,the two lines push the development of plot;intensify the depth of conflict and make the structure complete.It seems the author told us a story,but indeed it gives us a lot of inspiration and education. 展开更多
关键词 plot analysis double-line structure CONFLICT arrangement
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A linear analysis of the space structure of the standard plot in city
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作者 Yang Qingyuan,female,32 years old,associate professor. Yang Qingyuan Department of Urban Science,Environment and Resources,Southwest China Normal University,Chongqing 400715 《西南师范大学学报(自然科学版)》 CAS CSCD 北大核心 1998年第5期107-115,共9页
City’sstandardplotsaresomelandblockssetupinaregion,whichlandquality,individualfactors,landusebenefitandpr... City’sstandardplotsaresomelandblockssetupinaregion,whichlandquality,individualfactors,landusebenefitandpricearerepresentat... 展开更多
关键词 STANDARD plot SPACE DISPOSITION LINEAR analysis road network
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Effects of Hyperventilation on Venous-Arterial Bicarbonate Concentration Difference: A Possible Pitfall in Venous Blood Gas Analysis 被引量:1
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作者 Akira Umeda Kazuteru Kawasaki +2 位作者 Tadashi Abe Tateki Yamane Yasumasa Okada 《International Journal of Clinical Medicine》 2014年第2期76-80,共5页
Objectives: Recent reports on venous blood gas analysis have shown that venous bicarbonate concentration is useful in the evaluation of the body acid-base status. Most of these reports have been based on the Bland-Alt... Objectives: Recent reports on venous blood gas analysis have shown that venous bicarbonate concentration is useful in the evaluation of the body acid-base status. Most of these reports have been based on the Bland-Altman analysis comparing arterial and venous blood gas values. We intended to elucidate any factors that decrease the agreement between venous and arterial bicarbonate concentrations, which might impair the usefulness of venous blood gas analysis. Methods: Healthy volunteers and patients with various diseases (n = 141) were evaluated by simultaneous arterial and venous blood sampling and Bland-Altman analysis. The venous-arterial bicarbonate concentration difference was compared between healthy volunteers and untreated respiratory alkalosis patients. Intentional hyperventilation (30 or 60 breaths/min, for 3 min) was also performed on 6 healthy volunteers and the venous-arterial bicarbonate concentration difference was evaluated. Results: The relative average bias in bicarbonate concentration was 2.00 mEq/l with venous bicarbonate higher than arterial bicarbonate with 95% limits of agreement of ±4.15 mEq/l. Hyperventilation challenges increased the venous-arterial bicarbonate concentration difference in an intensity-dependent manner. The venous-arterial bicarbonate concentration difference was higher in untreated respiratory alkalosis patients than in healthy volunteers (P Conclusion: Although venous bicarbonate may be useful to evaluate the body acid-base status, hyperventilation increases the venous-arterial bicarbonate concentration difference. Physicians should keep this phenomenon in mind. 展开更多
关键词 HYPERVENTILATION BICARBONATE bland-altman analysis VENOUS Blood Gas analysis
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Post-Hoc Comparison in Survival Analysis: An Easy Approach
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作者 Arunabh Tripathi Anant Pandey 《Journal of Biosciences and Medicines》 2017年第3期112-119,共8页
Survival studies mainly deal with distribution of time to event. Often in such studies researchers are interested in comparing several treatment or prognostic groups. At the time of analysis, there is an unmeasured ch... Survival studies mainly deal with distribution of time to event. Often in such studies researchers are interested in comparing several treatment or prognostic groups. At the time of analysis, there is an unmeasured chance of making type I error, or finding a falsely significant difference between any two groups. The chance of making type I error is increased, if multiple groups are compared simultaneously. In this paper, survival analysis with Bonferroni correction is explained in easy way to cope up with this issue. The DLHS-3 data are taken to explain this methodology in the context of neonatal survival. Kaplan-meier plot with three survival comparison test is used to elaborate the application of Bonferroni correction. 展开更多
关键词 SURVIVAL analysis Bonferroni CORRECTION Kaplan-Meier plot
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Predicting Yield and Stability Analysis of Wheat under Different Crop Management Systems across Agro-Ecosystems in India
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作者 Mangi Lal Jat Raj Kumar Jat +6 位作者 Parvinder Singh Shankar Lal Jat Harminder Singh Sidhu Hanuman Sahay Jat Deepak Bijarniya Chiter Mal Parihar Raj Gupta 《American Journal of Plant Sciences》 2017年第8期1977-2012,共36页
The objectives of the study were as follows: 1) to evaluate the GxExM for wheat genotypes;2) to predict yield performance and identify high stable wheat genotypes in different management practices;and 3) to make genot... The objectives of the study were as follows: 1) to evaluate the GxExM for wheat genotypes;2) to predict yield performance and identify high stable wheat genotypes in different management practices;and 3) to make genotype-specific management and high performing genotype recommendations within and across agro-ecological regions. A diverse set of twenty-one genotypes was evaluated over three years (2012, 2013 and 2014) under two levels of crop management practices (CT and ZT) across three agro-ecological regions (BR, MP and PB) of India in replicated trials. Data were analyzed with SASGxE and RGxE programs using SAS and R programming languages, respectively. Across and within a location(s), the pattern of GxExM and GxMxY interactions (respectively) among univariate and multivariate stability statistics, grouping of genotypes in divisive clusters and estimates (with a prediction interval) of genotype varied in management practice CT and ZT. Across locations, the genotypes “Munal” and “HD-2967” were the best performers and high stable in CT and ZT, respectively. Genotypes “HD-2824” and “DPW-621-50”, and “Munal” may serve as diverse parents for developing high quality, climate smart, locally adapted genotypes for BR in CT and ZT, respectively. Genotypes “HD-2932”, “BAZ” and “JW-3288”, and “GW-322” and “HD-2967” are suitable for developing locally adapted stress tolerant genotypes for MP in management practices CT and ZT, respectively. Relatively small GxM and GxExM interactions in PB preclude in making definitive conclusions. 展开更多
关键词 STABILITY analysis GxExM BLUPs Forest plotS GGE BIplot WHEAT Univariate STABILITY STATISTICS
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Parameter Sensitivity and Qualitative Analysis of Dynamics of Ovarian Tumor Growth Model with Treatment Strategy
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作者 Md. Shah Alam Md. Kamrujjaman Md. Shafiqul Islam 《Journal of Applied Mathematics and Physics》 2020年第6期941-955,共15页
In this paper, we are interested to find the most sensitive parameter, local and global stability of ovarian tumor growth model. For sensitivity analysis, we use Latin Hypercube Sampling (LHS) method to generate sampl... In this paper, we are interested to find the most sensitive parameter, local and global stability of ovarian tumor growth model. For sensitivity analysis, we use Latin Hypercube Sampling (LHS) method to generate sample points and Partial Rank Correlation Coefficient (PRCC) method, uses those sample points to find out which parameters are important for the model. Based on our findings, we suggest some treatment strategies. We investigate the sensitivity of the parameters for tumor volume, <em>y</em>, cell nutrient density, <em>Q</em> and maximum tumor size, <em>ymax</em>. We also use Scatter Plot method using LHS samples to show the consistency of the results obtained by using PRCC. Moreover, we discuss the qualitative analysis of ovarian tumor growth model investigating the local and global stability. 展开更多
关键词 Parameter Sensitivity Latin Hypercube Sampling Partial Rank Correlation Coefficient Scatter plot MONOTONICITY Stability analysis
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Early Building Design:Informed decision-making by exploring multidimensional design space using sensitivity analysis 被引量:1
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作者 Torben Φstergrd Rasmus L.Jensen +1 位作者 Steffen E.Maagaard 侯恩哲 《建筑节能》 CAS 2017年第5期75-75,共1页
This paper describes a novel approach to explore a multidimensional design space and guide multi-actor decision making in the design of sustainable buildings.The aim is to provide proactive and holistic guidance of th... This paper describes a novel approach to explore a multidimensional design space and guide multi-actor decision making in the design of sustainable buildings.The aim is to provide proactive and holistic guidance of the design team.We propose to perform exhaustive Monte Carlo simulations in an iterative design approach that consists of tw o steps:1) preparation by the modeler,and 2) a multi-collaborator meeting.In the preparation phase,the simulation modeler performs Morris sensitivity analysis to fixate insignificant model inputs and to identify non-linearity and interaction effects.Next,a representation of the global design space is obtained from thousands of simulations using low-discrepancysequences(LPτ) for sampling.From these simulations,the modeler constructs fast metamodels and performs quantitative sensitivity analysis.During the meeting,the design team explores the global design space by filtering the thousands of simulations.Variable filter criteria are easily applied using an interactive parallel coordinate plot w hich provide immediate feedback on requirements and design choices.Sensitivity measures and metamodels show the combined effects of changing a single input and how to remedy unw anted output changes.The proposed methodology has been developed and tested through real building cases using a normative model to assess energy demand,thermal comfort,and daylight. 展开更多
关键词 comfort HOLISTIC iterative interactive PROACTIVE sustainable COORDINATE REMEDY STEPS EXPLORING
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金花菜叶绿体基因组特征及密码子偏好性分析
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作者 尹明华 胡佳欣 +2 位作者 李瑶瑶 刘曼情 欧阳克蕙 《草业科学》 CAS CSCD 北大核心 2024年第4期884-898,共15页
本研究对金花菜(Medicago polymorpha,JHC,江苏)叶绿体基因组进行BGISEQ-500平台测序,对其基因进行Noveplastys组装和GeSeq注释,最后通过MISA、REPuter、Gview、VISTA tools、IRscope和DNADnaSP6.0等软件对其序列特征、基因种类、密码... 本研究对金花菜(Medicago polymorpha,JHC,江苏)叶绿体基因组进行BGISEQ-500平台测序,对其基因进行Noveplastys组装和GeSeq注释,最后通过MISA、REPuter、Gview、VISTA tools、IRscope和DNADnaSP6.0等软件对其序列特征、基因种类、密码子偏好性以及系统发育进行分析。结果表明,JHC叶绿体基因组大小为124163 bp,无四分体结构,基因组总GC含量为34.09%,共注释出111个基因(76个CDS基因、30个tRNA基因、4个rRNA基因、1个假基因)、91个SSR位点和148个长重复序列;JHC叶绿体基因组的第三位密码子偏好以A和U作为末尾碱基,UUA、GCU、UAA、ACU、CCU、GAA、GUA、AUU、UGU、GGU、UUU、CUU为JHC叶绿体基因组的最优密码子;JHC与MZ772862(云南)亲缘关系较近,与MW971560(美国)、NC_042848(美国)关系较远,表明中国金花菜与美国金花菜的起源存在差异。 展开更多
关键词 金花菜 叶绿体基因组 中性绘图分析 ENC-plot分析 PR2-plot分析 最优密码子 系统发育分析
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Box-plot-SA-BP:变压器DGA多参量故障诊断模型
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作者 周威振 赵银山 +1 位作者 王兴 张鹏望 《电力大数据》 2023年第5期44-52,共9页
油中溶解气体分析(DGA)方法是一种典型的充油电力设备故障诊断方法,广泛应用于电力变压器故障检测与状态评估,但由于样本数据的可靠性和诊断模型的有效性影响,导致DGA诊断方法准确率较低。文中提出了一种Box-plot-SA-BP模型,首先,采用Bo... 油中溶解气体分析(DGA)方法是一种典型的充油电力设备故障诊断方法,广泛应用于电力变压器故障检测与状态评估,但由于样本数据的可靠性和诊断模型的有效性影响,导致DGA诊断方法准确率较低。文中提出了一种Box-plot-SA-BP模型,首先,采用Box-plot数据检测法去除异常数据以解决数据质量的问题,然后,利用自注意力机制(Self-attention, SA)准确捕捉多参量样本数据间的联系,提取更加稳定可靠的特征,最后设计BP网络多分类模型实现变压器故障诊断。对比实验证明了Box-plot-SA-BP模型的良好性能,具有较高的应用价值。 展开更多
关键词 油中溶解气体分析 箱线图 自注意力机制 BP神经网络 变压器故障诊断
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基于EDA统计图量化的桥梁动态监测数据质量评估
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作者 殷鹏程 谭曼丽莎 +1 位作者 曹阳梅 单德山 《重庆交通大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第5期9-16,共8页
探索性数据分析统计图在桥梁健康监测动态数据质量评估中已有广泛应用。为了减少人工观察统计图的主观性,通过近似度量方法实现统计图的量化分析,得到多个指标对监测数据进行快速质量评估。在运营环境激励作用下,桥梁结构动力响应具有... 探索性数据分析统计图在桥梁健康监测动态数据质量评估中已有广泛应用。为了减少人工观察统计图的主观性,通过近似度量方法实现统计图的量化分析,得到多个指标对监测数据进行快速质量评估。在运营环境激励作用下,桥梁结构动力响应具有短时线性平稳性,近似服从正态分布。以某大跨斜拉桥振动数据为研究对象,首先,绘制样本数据直方图和Q-Q图,通过观察数据分布特征预先判断数据质量,确定优、良和差3个等级。然后,分别通过KL散度和余弦相似度2种近似度量方法对样本数据直方图和Q-Q图进行量化,得到数据服从正态分布程度的指标;通过箱线图检测样本数据全局异常点,得到正常数据占比;统计分析得到量化值和先验质量等级的对应关系,确定以直方图KL散度和余弦相似度为主、以箱线图正常数据占比为辅的数据质量评估标准。最后,取部分数据为验证集,进一步验证所提方法各个指标的合理性,并给出该方法在实际工程上的应用结果。 展开更多
关键词 桥梁工程 桥梁结构健康监测 数据质量评估 探索性数据分析 KL散度 余弦相似度 箱线图
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即“小”见大——基于城市形态学方法的近代上海小型里弄研究
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作者 张劭祯 李颖春 袁菁 《建筑师》 2024年第3期125-132,共8页
本文基于上海老城厢历史文化风貌区金家坊片区的调研,借鉴康泽恩城镇平面格局分析法,界定出“小型里弄”这一新的里弄建筑类型,从产权地块形态、土地利用方式和房屋建设主体三个层面,考察其空间特征,并对形态背后的社会、经济和文化驱... 本文基于上海老城厢历史文化风貌区金家坊片区的调研,借鉴康泽恩城镇平面格局分析法,界定出“小型里弄”这一新的里弄建筑类型,从产权地块形态、土地利用方式和房屋建设主体三个层面,考察其空间特征,并对形态背后的社会、经济和文化驱动力进行初步探讨。研究丰富了对里弄建筑类型及空间多样性的认知,并为近代城市遗产的价值认定和保护对策奠定基础。 展开更多
关键词 城市形态 城镇平面格局分析 产权地块 小型里弄 上海老城厢
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池州地区冬季固态降水相态判别指标研究
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作者 孙卉 吴语燕 +3 位作者 宣普 蔡茶花 王惠 张明明 《气象与环境科学》 2024年第2期9-15,共7页
采用池州站地面气象观测资料,遴选出20032019年冬半年固态降水过程。根据T-mode主成分分析(TPCA)法,将冬半年环流形势分为一槽一脊型(Ⅰ型)、纬向波动型(Ⅱ型)和两槽一脊型(Ⅲ型)。其中,Ⅰ型的占比最多(45.2%),Ⅱ型的次之(28.8%),Ⅲ型... 采用池州站地面气象观测资料,遴选出20032019年冬半年固态降水过程。根据T-mode主成分分析(TPCA)法,将冬半年环流形势分为一槽一脊型(Ⅰ型)、纬向波动型(Ⅱ型)和两槽一脊型(Ⅲ型)。其中,Ⅰ型的占比最多(45.2%),Ⅱ型的次之(28.8%),Ⅲ型的占比最少(25.9%)。池州地区固态降水主要受中路冷空气影响。统计固态降水过程中的4种降水相态:雨、雨夹雪、雪、直接降雪,共得到降雨样本43个,雨夹雪样本54个,降雪样本39个,直接降雪样本52个,分别统计其出现时间;再根据箱线图法,使用ERA5资料中的高空各层温度、0℃高度、厚度层结,以及气象观测站的地面温度等进行分析,得出判别指标,并进行检验。结果表明:t_(1000hPa)<0℃、t_(925hPa)<-3℃、t_(850hPa)<-3℃且t_(2m)<0.8℃时会出现雨转雪;t_(1000hPa)<-1.3℃和t_(850hPa)<-5.7℃时为直接降雪;中低层普遍存在逆温;0℃层高度<260 m时基本为纯雪,0℃层高度>266 m为雨;H_(700-850hPa)雨雪转换临界值为154 dagpm,153 dagpm以下为直接降雪,H_(850-1000hPa)<129 dagpm为纯雪,128 dagpm以下时为直接降雪;雨夹雪判别指标不明,其中地面气温效果相对较好。 展开更多
关键词 降水相态 T-mode主成分分析 判别指标 箱线图 厚度层结
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二、三维结合的农村土地确权方法
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作者 陈丹 黄明东 陈文新 《北京测绘》 2024年第5期805-814,共10页
本文旨在解决农村土地确权过程中存在的信息化、智能化管理问题,设计并实现了一个基于二、三维结合的农村土地确权系统。该系统利用二维地图和三维地形模型相结合的方式,实现了对农村土地的全面信息采集和确权管理。本文首先介绍了农村... 本文旨在解决农村土地确权过程中存在的信息化、智能化管理问题,设计并实现了一个基于二、三维结合的农村土地确权系统。该系统利用二维地图和三维地形模型相结合的方式,实现了对农村土地的全面信息采集和确权管理。本文首先介绍了农村土地确权的背景,以及农村土地确权系统的基本概念,设计了一个具有五层结构的二、三维结合的农村土地确权系统,然后对椭球体表面不规则多边形面积计算、地块图斑界址点自动计算、跨库跨表数据关联分析、统计报表自动生成、三维数据展示及三维地形信息图形化提取等关键技术方法进行了详细描述。最后,本文对该系统功能进行了实现,展示系统界面。该系统通过地理信息系统和三维重建技术,辅助用户在二维地图上标记地块位置,并在三维地形模型上展示土地形状、地貌等信息。同时,系统还提供了数据录入、查询、报表自动生成及批量导出等功能,实现了农村土地确权的全过程信息化管理。因此,该系统能够提高土地确权的准确性和效率,为农村土地确权工作提供有效的支持。 展开更多
关键词 土地确权 地块图斑 数据关联分析 三维展示 地理信息系统
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基于回归分析的径流小区产流产沙量与降雨强度关系研究分析
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作者 朱小辉 陈拓嘉 《陕西水利》 2024年第5期118-120,共3页
以丽水石牛站为例,基于回归分析方法,研究径流小区产流产沙量与降雨强度之间的关系。通过收集丽水石牛站5个径流小区2022年的降雨、产流、产沙量数据,通过回归分析建立产流产沙量与降雨强度关系,并得出结论:随着降雨强度的增加,径流小... 以丽水石牛站为例,基于回归分析方法,研究径流小区产流产沙量与降雨强度之间的关系。通过收集丽水石牛站5个径流小区2022年的降雨、产流、产沙量数据,通过回归分析建立产流产沙量与降雨强度关系,并得出结论:随着降雨强度的增加,径流小区的产流量和产沙量也随之增加,呈现出明显的正相关关系,此外各径流小区的产流产沙量大小为裸地>桃树>杨梅>茶叶>茶花,说明种植均能对径流泥沙进行有效拦蓄,可作为防治水土流失的有效措施。 展开更多
关键词 回归分析 径流小区 产流产沙量 降雨强度
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