期刊文献+
共找到48篇文章
< 1 2 3 >
每页显示 20 50 100
对应分析和T-TEST在我国居民收入结构中的应用——基于2006年《中国统计年鉴》的实证研究 被引量:3
1
作者 袁亮 唐红桃 陈恭军 《技术经济与管理研究》 2007年第5期51-54,共4页
从上世纪末至今,我国政府已经在全国范围内实施了包括"西部大开发"和"建设新农村"在内的多项重大的宏观经济政策。本文以"我国2005年城乡居民人均收入的统计数据"为基础,以"居民收入结构和水平"... 从上世纪末至今,我国政府已经在全国范围内实施了包括"西部大开发"和"建设新农村"在内的多项重大的宏观经济政策。本文以"我国2005年城乡居民人均收入的统计数据"为基础,以"居民收入结构和水平"为视角,以"对应分析和T-TEST"为方法,以"SAS8·2统计分析软件"为工具,对宏观经济政策的经济效果进行了检验。分析结果表明:1·城乡、东西部地区居民的收入结构较政策实施前发生了显著的积极变化;2·城乡间、东西部居民的人均收入水平的提高,但差距在扩大。 展开更多
关键词 对应分析 t-test SAS8.2 收入结构
下载PDF
A New Maximum Test via the Dependent Samples t-Test and the Wilcoxon Signed-Ranks Test 被引量:2
2
作者 Saverpierre Maggio Shlomo S. Sawilowsky 《Applied Mathematics》 2014年第1期110-114,共5页
A maximum test in lieu of forcing a choice between the two dependent samples t-test and Wilcoxon signed-ranks test is proposed. The maximum test, which requires a new table of critical values, maintains nominal α whi... A maximum test in lieu of forcing a choice between the two dependent samples t-test and Wilcoxon signed-ranks test is proposed. The maximum test, which requires a new table of critical values, maintains nominal α while guaranteeing the maximum power of the two constituent tests. Critical values, obtained via Monte Carlo methods, are uniformly smaller than the Bonferroni-Dunn adjustment, giving it power superiority when testing for treatment alternatives of shift in location parameter when data are sampled from non-normal distributions. 展开更多
关键词 MAXIMUM TEST DEPENDENT SAMPLES t-test Wilcoxon Signed-Ranks TEST Bonferroni-Dunn Adjustment Experiment-Wise Type I Error Inferential Statistics Monte Carlo Method
下载PDF
A New Hybrid Feature Selection Method Using T-test and Fitness Function
3
作者 Husam Ali Abdulmohsin Hala Bahjat Abdul Wahab Abdul Mohssen Jaber Abdul Hossen 《Computers, Materials & Continua》 SCIE EI 2021年第9期3997-4016,共20页
Feature selection(FS)(or feature dimensional reduction,or feature optimization)is an essential process in pattern recognition and machine learning because of its enhanced classification speed and accuracy and reduced ... Feature selection(FS)(or feature dimensional reduction,or feature optimization)is an essential process in pattern recognition and machine learning because of its enhanced classification speed and accuracy and reduced system complexity.FS reduces the number of features extracted in the feature extraction phase by reducing highly correlated features,retaining features with high information gain,and removing features with no weights in classification.In this work,an FS filter-type statistical method is designed and implemented,utilizing a t-test to decrease the convergence between feature subsets by calculating the quality of performance value(QoPV).The approach utilizes the well-designed fitness function to calculate the strength of recognition value(SoRV).The two values are used to rank all features according to the final weight(FW)calculated for each feature subset using a function that prioritizes feature subsets with high SoRV values.An FW is assigned to each feature subset,and those with FWs less than a predefined threshold are removed from the feature subset domain.Experiments are implemented on three datasets:Ryerson Audio-Visual Database of Emotional Speech and Song,Berlin,and Surrey Audio-Visual Expressed Emotion.The performance of the F-test and F-score FS methods are compared to those of the proposed method.Tests are also conducted on a system before and after deploying the FS methods.Results demonstrate the comparative efficiency of the proposed method.The complexity of the system is calculated based on the time overhead required before and after FS.Results show that the proposed method can reduce system complexity. 展开更多
关键词 Feature selection dimensional reduction feature optimization pattern recognition CLASSIFICATION t-test
下载PDF
Comparison of the results of T-Test from different versions of Epi Info
4
作者 Junke Tang Jinliang Zhu 《Journal of Nanjing Medical University》 2005年第4期210-213,共4页
Objective: To take advantage of Epi Info to manage and analyze disease data. Methods: After selecting the living examples for independent sample T-Test, Epi Info 5.00, 5.01a(Chinese), 6.00, 6.04 b, 6.04 d, 2000, 2... Objective: To take advantage of Epi Info to manage and analyze disease data. Methods: After selecting the living examples for independent sample T-Test, Epi Info 5.00, 5.01a(Chinese), 6.00, 6.04 b, 6.04 d, 2000, 2002(Chinese)were used to do the independent sample T-Test on the two living examples. Then, Intercooled StataT, Microsoft Excel(2002) and SPSS 10.0 for Windows were used to verify the results. Results: The statistical results from the Epi Info 5.00, 5.01a(Chinese) and 6.00 were the same while that from Epi Info 6.04 b, 6.04 d, 2000,2002 (Chinese), Intercooled StataT, Microsoft Excel(2002) and SPSS 10.0 for Windows were identical In independent sample T-Test,. But the former result is different with the latter. Conclusion: There was an error in the result of T-Test from Epi Info 6.00 and former versions. Thus, it's important to be alert to select the versions of Epi Info to manage and analyze disease data. On the other hand, it's also quite pivotal to distinguish the adopted Epi Info versions when referring to the articles ane use the statistical results. 展开更多
关键词 Epi Info t-test disease data management and analysis
下载PDF
Excel应用于显著性检验的实训过程探究 被引量:7
5
作者 万海清 赵东海 《农业网络信息》 2011年第6期13-16,共4页
在Excel环境中采取编算式并调用粘贴函数,逐步实现了单个或两个样本的显著性检验过程。其中的数据分析软件运行T检验、F检验过程的结果进行比较,发现其中的不同之处有时会造成误判。明确这些差别有助于澄清显著性检验的每一个步骤和细节... 在Excel环境中采取编算式并调用粘贴函数,逐步实现了单个或两个样本的显著性检验过程。其中的数据分析软件运行T检验、F检验过程的结果进行比较,发现其中的不同之处有时会造成误判。明确这些差别有助于澄清显著性检验的每一个步骤和细节,正确运用Excel界面编程或通过运行数据分析软件提高效率。Excel界面用作生物统计课程实训操作平台,具有毋庸置疑的价值和优势,对于初学者,使用Excel电子表格逐步实现各种统计检验过程取得的教学效果,其他任何专业统计软件都无法替代。 展开更多
关键词 单元格块 观测值 变量 粘贴函数 t-test
下载PDF
GB/T5711-1997测试方法中主要影响因素的量化关系解析 被引量:3
6
作者 黄松 陈明 《纺织报告》 2015年第2期47-52,共6页
本文采用6因子2水平筛选因子设计试验,以吸光度Abs作为响应值,采用统计分析手段,尝试量化耐干洗色牢度GB/T5711-1997测试方法中的主、次要影响因素。运用t-test检验、分散分析和效应的Pareto图得知,耐干洗色牢度测试中的主要影响因素的... 本文采用6因子2水平筛选因子设计试验,以吸光度Abs作为响应值,采用统计分析手段,尝试量化耐干洗色牢度GB/T5711-1997测试方法中的主、次要影响因素。运用t-test检验、分散分析和效应的Pareto图得知,耐干洗色牢度测试中的主要影响因素的效应大小顺序为溶剂量(D)>样品尺寸(A)>样品尺寸与溶剂量(AD)>温度(B)>钢片数(E),其中样品尺寸与溶剂量有着显著的交互作用。耐干洗色牢度测试中的时间、布袋因素为次要影响因素,效应不显著。 展开更多
关键词 耐干洗色牢度 GB/T5711-1997 吸光度 t-test检验 分散分析 Pareto图
下载PDF
选择性视觉注意模型评价方法探析 被引量:1
7
作者 张倩 《中国市场》 2016年第51期140-141,共2页
计算机视觉领域内,为了模拟人类视觉系统,越来越多的视觉注意模型不断涌现,但缺乏对其进行客观、公正、合理的评价方法体系。针对此问题,首先,对现有模型广泛使用的测试图像集和评价模型的性能指标进行梳理和总结;其次,将统计学中的均... 计算机视觉领域内,为了模拟人类视觉系统,越来越多的视觉注意模型不断涌现,但缺乏对其进行客观、公正、合理的评价方法体系。针对此问题,首先,对现有模型广泛使用的测试图像集和评价模型的性能指标进行梳理和总结;其次,将统计学中的均方差指标和双侧T-test假设检验方法引到选择性视觉注意模型的显著性评价上;最后,提出一个综合评价视觉注意模型的方法体系准则,经实验验证与文献分析其评价结果较为客观、公正、可信。 展开更多
关键词 视觉注意模型 评价方法 均方差指标 双侧t-test假设检验 综合评价
下载PDF
美国干洗业顾客满意度分析及营销策略研究——以Sarni Cleaners为例 被引量:1
8
作者 沈滔 《重庆科技学院学报(社会科学版)》 2017年第9期55-56,72,共3页
概括了美国干洗业现状,以Sarni Cleaners公司为例对干洗业顾客满意度进行调查,使用Frequency分析、T-test检验、One-way ANOVA等分析方法,找出其影响因素,得出研究结论,并对该公司提出营销策略建议。
关键词 美国干洗业 顾客满意度 单因素方差分析 t-test 营销策略
下载PDF
AIFRS国际会计制度对澳大利亚会计报表的影响(英文)
9
作者 彭娟娟 《宿州学院学报》 2008年第6期56-59,共4页
自财政年度2005年,澳大利亚开始采用IFRS国际会计制度,这是通向国际会计规则一体化的重要一步,并且此一体化进程已经涉及到除澳大利亚外的世界很多国家。然而,至今在学术界仍有关于此国际会计制度引进的优缺点的激烈的争论。此论文将要... 自财政年度2005年,澳大利亚开始采用IFRS国际会计制度,这是通向国际会计规则一体化的重要一步,并且此一体化进程已经涉及到除澳大利亚外的世界很多国家。然而,至今在学术界仍有关于此国际会计制度引进的优缺点的激烈的争论。此论文将要通过实证的方法对这一从早前的AGAAP到AIFRS的转变对澳大利亚公司的影响进行研究。所用会计数据来自随机选择的澳大利亚金融行业的30个上市公司。此论文的研究结果表明此国际会计制度引进总体而言并未对澳大利亚公司的会计报表数据有显著的影响。 展开更多
关键词 AIFRS国际会计制度 澳大利亚上市公司 t-tests 会计项目 金融产业
下载PDF
An Analysis of Fights in the National Hockey League
10
作者 Henry L. Castillo Paul M. Sommers 《Open Journal of Statistics》 2017年第4期676-688,共13页
The authors use data from fight logs during the 2016-2017 regular National Hockey League (NHL) season to test for a difference in the proportion of games with and without fights for each of the thirty NHL teams. Only ... The authors use data from fight logs during the 2016-2017 regular National Hockey League (NHL) season to test for a difference in the proportion of games with and without fights for each of the thirty NHL teams. Only one team (Toronto Maple Leafs) was more likely to be involved in a fight at a home game than at an away game. Teams that fought proportionally more often in the second half of the season made the playoffs;teams that fought significantly less often did not. And, long distance air travel (flights involving more than 1000 miles or trips that required crossing at least one time zone) resulted in disproportionately more games with fights for eight different NHL teams. 展开更多
关键词 National HOCKEY LEAGUE VIOLENCE in SPORTS t-tests Involving PROPORTIONS
下载PDF
Has Tom Brady Passed His Prime?
11
作者 Paul M. Sommers 《Open Journal of Statistics》 2018年第5期831-836,共6页
The author examines the career passing statistics of Tom Brady (2000 to present), quarterback for the New England Patriots of the National Football League (NFL). In the categories of completions, attempts, completion ... The author examines the career passing statistics of Tom Brady (2000 to present), quarterback for the New England Patriots of the National Football League (NFL). In the categories of completions, attempts, completion percentage, passing yards, yards per attempt, touchdowns, and interceptions, there is no evidence of decline in per game averages since 2008 (when he tore his ACL) relative to his seven seasons as a starter before 2008. Moreover, there is no evidence of any statistically discernible performance change in his most recent four seasons as a starter relative to the three prior seasons. His consistency based on the coefficient of variation in games won is marginally better than his consistency in games lost, with one notable exception. Tom Brady’s interceptions per game were more consistent during losses than they were during wins. 展开更多
关键词 National FOOTBALL LEAGUE TOM Brady 2-Sample t-tests
下载PDF
Do States with Professional Sports Teams Have Lower Suicide Rates?
12
作者 Paul M. Sommers 《Open Journal of Statistics》 2018年第5期760-769,共10页
The author examines six age-group specific suicide rates in 2016 between states (in the continental United States) with and without professional sports teams in baseball [MLB], football [NFL], hockey [NHL], and basket... The author examines six age-group specific suicide rates in 2016 between states (in the continental United States) with and without professional sports teams in baseball [MLB], football [NFL], hockey [NHL], and basketball [NBA]. States with at least one team in baseball or football have significantly lower suicide rates among adults in all six age groups (over 20 years of age). States with at least one hockey team have significantly lower suicide rates for all adults over the age of 20, except the oldest age group (adults 65 years of age or over). The results are weakest for states with at least one basketball team. Adults only between 25 and 44 years of age and 65 years of age or over have significantly lower suicide rates with at least one NBA team. 展开更多
关键词 PROFESSIONAL TEAM SPORTS SUICIDE Rates U.S. STATES 2-Sample t-tests Chi-Squared Test
下载PDF
GIFT密码算法的二阶门限实现及其安全性评估 被引量:2
13
作者 蒋宏然 韦永壮 +1 位作者 史佳利 刘争红 《计算机应用研究》 CSCD 北大核心 2020年第8期2455-2459,共5页
目前已知GIFT算法的防护方案仅能抗一阶功耗攻击。为了使该算法能抵御高阶功耗攻击,利用GIFT算法的数学结构,结合门限实现方法,构造了GIFT算法的二阶门限实现方案;针对非线性部件S盒的数学特征,分别构建(3,9),(6,7)以及(5,10)等二阶门... 目前已知GIFT算法的防护方案仅能抗一阶功耗攻击。为了使该算法能抵御高阶功耗攻击,利用GIFT算法的数学结构,结合门限实现方法,构造了GIFT算法的二阶门限实现方案;针对非线性部件S盒的数学特征,分别构建(3,9),(6,7)以及(5,10)等二阶门限实现方案,并选取所需硬件资源最少的(3,9)方案,将其在FPGA平台下实现。在实现时,为了更好地分析对比所耗硬件资源,使用并行和串行的硬件实现方法。结果表明,在Nan Gate 45nm工艺库下,并行实现消耗的总面积为12 043 GE,串行实现消耗的总面积为6 373 GE。通过采集实际功耗曲线,利用T-test对该二阶门限实现方案进行侧信息泄露评估,证实了该二阶门限实现方案的安全性。 展开更多
关键词 GIFT算法 功耗攻击 门限实现 芯片面积 t-test
下载PDF
Detection and attribution of abrupt climate changes in the last one hundred years 被引量:3
14
作者 张文 万仕全 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第6期2311-2316,共6页
Based on physical backgrounds, the four time series of the Guliya (Tibetan plateau) ice core (GIC) 5180, and three natural factors, i.e. the rotation rate of earth, sunspots, and E1 Nino-Southern Oscillation (ENS... Based on physical backgrounds, the four time series of the Guliya (Tibetan plateau) ice core (GIC) 5180, and three natural factors, i.e. the rotation rate of earth, sunspots, and E1 Nino-Southern Oscillation (ENSO) signals, are decomposed into two hierarchies, i.e. more and less than 10-year hierarchies respectively, and then the running t-test is used to reanalyse the data before and after filtering with the purpose of investigating the contribution of natural factors to the abrupt climate changes in the last one hundred years. The results show that the GIC 5180 evolved with a quasi-period of 7-9 years, and the abrupt climate changes in the early 1960s and in the period from the end of the 1970s to the beginning of the 1980s resulted from the joint effect of the two hierarchies, in other words, the two interdecadal abrupt changes of climate in the last one hundred years were global. The interannual variations of ENSO and sunspots were the important triggering factors for the abrupt climate changes in the last one hundred years. At the same time, the method of Information Transfer (IT) is employed to estimate the contributions of ENSO signals and sunspots activities to the abrupt climate changes, and it is found that the contribution of the interannual variation of ENSO signals is relatively large. 展开更多
关键词 abrupt climate change time series analysis running t-test
下载PDF
The Statistical Significance Test of Regional Climate Change Caused by Land Use and Land Cover Variation in West China 被引量:2
15
作者 王汉杰 施伟来 陈晓红 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2006年第3期355-364,共10页
The West Development Policy being implemented in China is causing significant land use and land cover (LULC) changes in West China. With the up-to-date satellite database of the Global Land Cover Characteristics Dat... The West Development Policy being implemented in China is causing significant land use and land cover (LULC) changes in West China. With the up-to-date satellite database of the Global Land Cover Characteristics Database (GLCCD) that characterizes the lower boundary conditions, the regional climate model RIEMS-TEA is used to simulate possible impacts of the significant LULC variation. The model was run for five continuous three-month periods from 1 June to 1 September of 1993, 1994, 1995, 1996, and 1997, and the results of the five groups are examined by means of a student t-test to identify the statistical significance of regional climate variation. The main results are: (1) The regional climate is affected by the LULC variation because the equilibrium of water and heat transfer in the air-vegetation interface is changed. (2) The integrated impact of the LULC variation on regional climate is not only limited to West China where the LULC varies, but also to some areas in the model domain where the LULC does not vary at all. (3) The East Asian monsoon system and its vertical structure are adjusted by the large scale LULC variation in western China, where the consequences are the enhancement of the westward water vapor transfer from the east oast and the relevant increase of wet-hydrostatic energy in the middle-upper atmospheric layers. (4) The ecological engineering in West China affects significantly the regional climate in Northwest China, North China and the middle-lower reaches of the Yangtze River; there are obvious effects in South, Northeast, and Southwest China, but minor effects in Tibet. 展开更多
关键词 West Development Policy of China LULC variation regional climate simulation statistical t-test East Asian monsoon
下载PDF
RELATIONSHIP BETWEEN WINTERTIME THERMAL CONTRAST OVER THE ASIAN CONTINENT AND THE CLIMATE IN CHINA 被引量:1
16
作者 梁红丽 晏红明 +1 位作者 许彦艳 段玮 《Journal of Tropical Meteorology》 SCIE 2013年第4期375-387,共13页
Recent studies indicated that except for the land-sea thermal contrast,there also existed the land-land thermal contrast.The composite analysis and t-test method are used to further study the local thermal contrast va... Recent studies indicated that except for the land-sea thermal contrast,there also existed the land-land thermal contrast.The composite analysis and t-test method are used to further study the local thermal contrast variation over the Asian continent,and to discuss the association of seasonal variation of land thermal state with circulation over East Asia,the early summer and summer monsoon activity,and the precipitation anomaly in China in the decadal scale.Results show that the positive meridional temperature anomaly transports downward from upper tropospheric layers in middle-high latitudes north of 25°N in the positive years.In the zonal direction,the Tibetan Plateau heating in the successive spring acts as a force to influence the atmosphere,leading to the rapid temperature warming over eastern Chinese continent,which could increase the land-sea thermal contrast with the negative SSTA.Accordingly,the monsoon activity in early summer over East Asian establishes earlier and the summer monsoon intensity becomes stronger.The early summer precipitation is more-than-normal over the Yangtze River,and the summer precipitation is more-than-normal over the north China and the southwest China.The situation is contrary in the negative years. 展开更多
关键词 LAND-SEA THERMAL CONTRAST t-test method ASIAN CONTINENT monsoon activity circulation precipitation anomaly
下载PDF
珠江三角洲地区暴雨事件驱动因子研究
17
作者 宋金帛 张强 +1 位作者 王港 吴文欢 《北京师范大学学报(自然科学版)》 CAS CSCD 北大核心 2022年第2期293-299,共7页
利用CMORPH降水数据、ERA5气象数据、欧空局土地利用数据、热带气旋灾害资料等多源异构数据,运用相关分析、M-K检验、合成分析、Student’s t-test等多种统计方法辨识珠江三角洲地区暴雨关键驱动因子.研究发现:不同时间尺度上暴雨事件... 利用CMORPH降水数据、ERA5气象数据、欧空局土地利用数据、热带气旋灾害资料等多源异构数据,运用相关分析、M-K检验、合成分析、Student’s t-test等多种统计方法辨识珠江三角洲地区暴雨关键驱动因子.研究发现:不同时间尺度上暴雨事件年际变化趋势均不显著;净水汽通量、强热带风暴、气压变化等是研究区暴雨事件的主要驱动因子,夏季西北太平洋副高位置及强度对研究区暴雨的发生也有影响,城市化程度、厄尔尼诺/拉尼娜现象等对研究区暴雨事件影响不显著.研究结果可为珠三角暴雨事件、暴雨致洪及城市内涝的预测与灾害风险评估提供理论支撑和决策依据. 展开更多
关键词 暴雨事件 珠江三角洲 驱动因子 相关分析 M-K检验 Student’s t-test
下载PDF
Study of Heavy Metal Accumulation in Sewage Irrigated Vegetables in Different Regions of Agra District, India 被引量:1
18
作者 Preeti Parashar Fazal Masih Prasad 《Open Journal of Soil Science》 2013年第1期1-8,共8页
Heavy metal contamination of soil resulting from sewage irrigation is a cause of serious concern due to the potential health impacts of consuming contaminated products. In this study an assessment made of the impact o... Heavy metal contamination of soil resulting from sewage irrigation is a cause of serious concern due to the potential health impacts of consuming contaminated products. In this study an assessment made of the impact of sewage irrigation on heavy metal contamination of Spinach, Cabbage, Beetroot, Reddish, Okra, Tomato, and Cucumber is widely cultivated and consumed in urban India, particularly by the poor. A field study was conducted at seven major sites that were irrigated by either treated, (Dhandupura) or untreated wastewater in the suburban areas of Agra, India. Samples of irrigation water, soil, and the edible portion of all the vegetables were collected monthly during the winter seasons and were analyzed for Fe, Cd, Cu, Zn, and Pb. Heavy metals in irrigation water were below the internationally recom- mended (WHO) maximum permissible limits set for agricultural use for all heavy metals except Cd at all the sites. Similarly, the mean heavy metal concentrations in soil were below the Indian standards for all heavy metals, but the maximum value of Cd recorded during January was higher than the standard. However, in the edible portion of spinach, the Cd concentration was higher than the permissible limits of the Indian standard during summer, whereas Pb concentrations were higher in winter seasons. Results of correlation analysis were computed to assess the relationship between individual heavy metal concentration in the vegetable samples. The study concludes that the use of treated and untreated wastewater for irrigation has increased the contamination of Cd, Pb in edible portion of vegetables causing potential health risk in the long term from this practice. The study also points to the fact that adherence to standards for heavy metal contamination of soil and irrigation water does not ensure safe food. Fe was measured abundant in soil whereas Pb and Cd were found more in untreated sites as compared to treated site. Correlation, paired T-test and ANOVA were also carried out for pre post harvested soil and vegetables. 展开更多
关键词 HEAVY Metals AAS SEWAGE Pearson Correlation Paired t-test ANOVA
下载PDF
Trend and Periodicity of Temperature Time Series in Ontario 被引量:1
19
作者 Syed Imran Ahmed Ramesh Rudra +1 位作者 Trevor Dickinson Motahir Ahmed 《American Journal of Climate Change》 2014年第3期272-288,共17页
The trends and periodicities in the annual and seasonal temperature time series at fifteen weather stations within Ontario Great Lakes Basins have been analyzed, for the period 1941-2005, using the statistical analyse... The trends and periodicities in the annual and seasonal temperature time series at fifteen weather stations within Ontario Great Lakes Basins have been analyzed, for the period 1941-2005, using the statistical analyses (Fourier series analysis, t-test, and Mann-Kendall test). The stations were spatially divided into three regions: northwest (NW), southwest (SW), and southeast (SE) to evaluate spatial variability in temperature. The results of the study reveal that the annual maximum mean temperature showed increasing trend for NW, and mixed trends for SW and SE regions. The variability was found to be more for northern stations as compared to southern stations for annual extreme minimum temperature. In addition, the trend slope per 100 years for the average annual extreme minimum temperature increased within the range of -0.8°C (Stratford) to 15°C (Porcupine). The seasonal analysis demonstrated that extreme maximum temperature has an increasing trend and maximum mean temperature has a decreasing trend during summer and winter. The extreme minimum temperature for winter illustrated an increasing trend (90%) with 22% statistically significant for NW region. For the SW region, the trend is also increasing (80%) for most of the temperature variables and 25% of temperature data were significantly increased in the SW region. The SE region stations showed overall very clear increasing trends (95%) for all the temperature variables. The data also showed that 47% of data were statistically significant in the SE region. The analysis of variance accounted for by trend, significant periodicities, and random component show that the pattern is similar for the percent of variance accounted for periodicities, and random component contribute dominantly for the four temperature variables and frost free days (FFD) for all three regions. Overall, the study reveals that the extreme minimum temperature is increasing annually and seasonally, with statistically significant at many stations. 展开更多
关键词 Time Series TREND PERIODICITY MANN-KENDALL Test t-test FROST Free Days
下载PDF
一种确定肿瘤重要基因信息的有效算法
20
作者 康雨生 郭红 《信息系统工程》 2010年第10期49-51,共3页
肿瘤基因微阵列数据对于肿瘤诊断具有重要意义,由于基因数据具有数据样本少、基因维数高的特点,传统的分类器方法在样本数量不足或远远小于属性维数的情况下,易于陷入"过学习",分类精度较低。本文采用T-test选取获选基因,选... 肿瘤基因微阵列数据对于肿瘤诊断具有重要意义,由于基因数据具有数据样本少、基因维数高的特点,传统的分类器方法在样本数量不足或远远小于属性维数的情况下,易于陷入"过学习",分类精度较低。本文采用T-test选取获选基因,选取分布差异较大的基因,剔除无关基因,提高实验的整体效率;将支持向量机SVM的惩罚因子加入粒子群算法PSO的粒子编码,PSO同时对候选基因组和SVM参数进行搜索,减少SVM参数的不确定性,以此得到更精确的基因标签,确定好的分类因素。文章最后验证了算法的有效性。 展开更多
关键词 微阵列 t-test PSO SVM
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部