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
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
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
Sanjiang Plain,located in the northeast of Heilongjiang Province,is one of the important grain producing areas in Heilongjiang Province,which has made great contributions to China's grain industry.However,the rapi...Sanjiang Plain,located in the northeast of Heilongjiang Province,is one of the important grain producing areas in Heilongjiang Province,which has made great contributions to China's grain industry.However,the rapid development of agriculture has increased the demand for water resources,and the water cycle process has been damaged,which has caused a series of problems,and the adverse effects have aroused great concern from all sides.In order to study the evolution law of precipitation and runoff in the lower Songhua River basin of Sanjiang Plain,the monthly precipitation data of Fujin,Jiamusi and Yilan meteorological stations and the measured runoff data of Jiamusi and Changjiangtun hydrological stations of the Songhua River from 1956 to 2011 were used.Mann-Kendall method,Hurst index method,sliding T test and wavelet analysis were used to analyze the trend,mutability and periodicity of precipitation and runoff evolution.The results show that the annual precipitation and runoff of the lower Songhua River basin in Sanjiang Plain showed a downward trend in the past 56 years(1956-2011);the mutation time of precipitation at Fujin Station,Jiamusi Station and Yilan Station was 1987,1959 and 2007,1973,respectively,the mutation time of runoff at Jiamusi Station and Changjiangtun Station appeared in 1967 and 1988;the first main periods of the annual precipitation wavelets are 42 years,54 years and56 years,respectively,and the periods are about 28-31 years,36-39 years and 36-38 years,the annual runoff of Jiamusi Station has the first main period of 57 years and the period is about 37-40 years,and the annual runoff of Changjiangtun Station has the first main period of 35 years and the period is about 20-24 years;the freeze-thaw process has significant influence on runoff in the study area.The results of this study have practical significance for rational planning and utilization of surface water resources and joint operation of surface water and groundwater in Sanjiang Plain.展开更多
[Objective] The aim was to compare the morphology difference between male and female individuals of Paramisgurnus dabryanus Sauvage. [Method] The comparison of 10 morphological characteristics between male and female ...[Objective] The aim was to compare the morphology difference between male and female individuals of Paramisgurnus dabryanus Sauvage. [Method] The comparison of 10 morphological characteristics between male and female individuals of P. dabryanus was conducted with principal component analysis and t-test methods. [Result] The results of t-test indicated that three of 10 morphological characteristics showed extremely significant difference（P0.01）and one of 10 morphological characteristics was significantly different（P0.05）. Principal component analysis revealed four principal components,the contribution rate of which was 31.151%,18.844%,12.324% and 10.169%,respectively. The cumulative contribution rate had reached 72.487%. The morphological variations between male and female individuals were not significant,which was consistent with that of t-test. [Conclusion] The result in this study had provided theoretical basis for the breeding of P. dabryanus.展开更多
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
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
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
In order to investigate the effects of different geometrical parameters and pretightening loads on failure mode and bearing strength,a large number of single-bolted T300/QY8911 composite laminates were tested under st...In order to investigate the effects of different geometrical parameters and pretightening loads on failure mode and bearing strength,a large number of single-bolted T300/QY8911 composite laminates were tested under static tension load.Box-plot was used to extract the singular testing values of bearing strength and effective statistical values were obtained.T-test method of independent samples was used to study how much pretightening loads influence bearing strength.The results show that the geometrical parameters,such as ratios of width to hole diameter(w/d) and edge distance to hole diameter(e/d),remarkably influence failure mode and bearing strength.Net-section failure will occur when w/d is smaller than 4,and shear-out failure will occur when e/d is smaller than 2.Bearing failure or bearing and shear-out combined failure will occur when w/d is greater than 4 and e/d is greater than 2.There is an optimal combination of geometrical parameters to achieve the highest bearing strength.For most of specimens,pretightening loads do not explicitly influence bearing strength.展开更多
Upstream-downstream relationships of annual streamflow discharges and severity and frequency of stream-flow drought events are critical in understanding how streamflow droughts propagate over time and space. Such info...Upstream-downstream relationships of annual streamflow discharges and severity and frequency of stream-flow drought events are critical in understanding how streamflow droughts propagate over time and space. Such information can be used to resolve water disputes, trigger mitigation strategies, and understand how streamflow changes due to changes in the environment. During drought years, such information is even more critical as water resources are contested. The objective of this research is to study the upstream-downstream relationships of streamflow in Nebraska along four major river systems with diverse hydrologic characteris-tics and human activities: North Platte, Big Blue, Republican, and Niobrara. The relationships among the upstream and downstream stations along the four rivers are investigated by comparing several statistics de-rived from the annual flow discharge and on drought events. Trend analysis and coefficient of variation are applied to annual flow discharge values, and a host of drought-related parameters (e.g., annual maximum drought duration, annual accumulated drought duration, number of drought events) are also computed with respect to five different levels of streamflow drought events: water shortage, mild drought, moderate drought, significant drought, and extreme drought. The paired-t test and ANOVA with MIXED procedure are subse-quently applied to the statistics to observe whether there is a significant difference between upstream and downstream stations along a river. The analysis allows us to characterize the upstream-downstream relation-ships of the four river systems, laying the groundwork for further investigations to identify the reasons for some of the trends and observations. These findings will be essential in water resources management during or prior to hydrological droughts.展开更多
文摘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.
文摘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.
文摘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.
基金funded by Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences commissioned the project Research and Application of Key Technologies of Water Resources Allocation in Ten Million mu Irrigated Area of Sanjiang Plain,grant number XDA28100105。
文摘Sanjiang Plain,located in the northeast of Heilongjiang Province,is one of the important grain producing areas in Heilongjiang Province,which has made great contributions to China's grain industry.However,the rapid development of agriculture has increased the demand for water resources,and the water cycle process has been damaged,which has caused a series of problems,and the adverse effects have aroused great concern from all sides.In order to study the evolution law of precipitation and runoff in the lower Songhua River basin of Sanjiang Plain,the monthly precipitation data of Fujin,Jiamusi and Yilan meteorological stations and the measured runoff data of Jiamusi and Changjiangtun hydrological stations of the Songhua River from 1956 to 2011 were used.Mann-Kendall method,Hurst index method,sliding T test and wavelet analysis were used to analyze the trend,mutability and periodicity of precipitation and runoff evolution.The results show that the annual precipitation and runoff of the lower Songhua River basin in Sanjiang Plain showed a downward trend in the past 56 years(1956-2011);the mutation time of precipitation at Fujin Station,Jiamusi Station and Yilan Station was 1987,1959 and 2007,1973,respectively,the mutation time of runoff at Jiamusi Station and Changjiangtun Station appeared in 1967 and 1988;the first main periods of the annual precipitation wavelets are 42 years,54 years and56 years,respectively,and the periods are about 28-31 years,36-39 years and 36-38 years,the annual runoff of Jiamusi Station has the first main period of 57 years and the period is about 37-40 years,and the annual runoff of Changjiangtun Station has the first main period of 35 years and the period is about 20-24 years;the freeze-thaw process has significant influence on runoff in the study area.The results of this study have practical significance for rational planning and utilization of surface water resources and joint operation of surface water and groundwater in Sanjiang Plain.
基金Supported by Scientific and Technological Projects in Shandong Province~~
文摘[Objective] The aim was to compare the morphology difference between male and female individuals of Paramisgurnus dabryanus Sauvage. [Method] The comparison of 10 morphological characteristics between male and female individuals of P. dabryanus was conducted with principal component analysis and t-test methods. [Result] The results of t-test indicated that three of 10 morphological characteristics showed extremely significant difference（P0.01）and one of 10 morphological characteristics was significantly different（P0.05）. Principal component analysis revealed four principal components,the contribution rate of which was 31.151%,18.844%,12.324% and 10.169%,respectively. The cumulative contribution rate had reached 72.487%. The morphological variations between male and female individuals were not significant,which was consistent with that of t-test. [Conclusion] The result in this study had provided theoretical basis for the breeding of P. dabryanus.
基金Project supported by the National Natural Sciences Foundation of China (Grant No 40675044)the State Key Development Program for Basic Research (Grant No 2006CB400503)
文摘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.
文摘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.
基金Natural Science Fund projects of China(40675045,41065004)NSFC-Yunnan Joint Foundation(U0833602)National Public Benefit Research Foundation of China(GYHY201206017)
文摘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.
基金Project(51175424)supported by the National Natural Science Foundation of ChinaProject(B07050)supported by‘111’Program of ChinaProject(JC20110257)supported by the Basic Research Foundation of Northwestern Polytechnical University,China
文摘In order to investigate the effects of different geometrical parameters and pretightening loads on failure mode and bearing strength,a large number of single-bolted T300/QY8911 composite laminates were tested under static tension load.Box-plot was used to extract the singular testing values of bearing strength and effective statistical values were obtained.T-test method of independent samples was used to study how much pretightening loads influence bearing strength.The results show that the geometrical parameters,such as ratios of width to hole diameter(w/d) and edge distance to hole diameter(e/d),remarkably influence failure mode and bearing strength.Net-section failure will occur when w/d is smaller than 4,and shear-out failure will occur when e/d is smaller than 2.Bearing failure or bearing and shear-out combined failure will occur when w/d is greater than 4 and e/d is greater than 2.There is an optimal combination of geometrical parameters to achieve the highest bearing strength.For most of specimens,pretightening loads do not explicitly influence bearing strength.
文摘Upstream-downstream relationships of annual streamflow discharges and severity and frequency of stream-flow drought events are critical in understanding how streamflow droughts propagate over time and space. Such information can be used to resolve water disputes, trigger mitigation strategies, and understand how streamflow changes due to changes in the environment. During drought years, such information is even more critical as water resources are contested. The objective of this research is to study the upstream-downstream relationships of streamflow in Nebraska along four major river systems with diverse hydrologic characteris-tics and human activities: North Platte, Big Blue, Republican, and Niobrara. The relationships among the upstream and downstream stations along the four rivers are investigated by comparing several statistics de-rived from the annual flow discharge and on drought events. Trend analysis and coefficient of variation are applied to annual flow discharge values, and a host of drought-related parameters (e.g., annual maximum drought duration, annual accumulated drought duration, number of drought events) are also computed with respect to five different levels of streamflow drought events: water shortage, mild drought, moderate drought, significant drought, and extreme drought. The paired-t test and ANOVA with MIXED procedure are subse-quently applied to the statistics to observe whether there is a significant difference between upstream and downstream stations along a river. The analysis allows us to characterize the upstream-downstream relation-ships of the four river systems, laying the groundwork for further investigations to identify the reasons for some of the trends and observations. These findings will be essential in water resources management during or prior to hydrological droughts.
