Vehicle traveling time prediction is an important part of the research of intelligent transportation system. By now, there have been various kinds of methods for vehicle traveling time prediction. But few consider bot...Vehicle traveling time prediction is an important part of the research of intelligent transportation system. By now, there have been various kinds of methods for vehicle traveling time prediction. But few consider both aspects of time and space. In this paper, a vehicle traveling time prediction method based on grey theory （GT） and linear regression analysis （LRA） is presented. In aspects of time, we use the history data sequence of bus speed on a certain road to predict the future bus speed on that road by GT. And in aspects of space, we calculate the traffic affecting factors between various roads by LRA. Using these factors we can predict the vehicle＇s speed at the lower road if the vehicle＇s speed at the current road is known. Finally we use time factor and space factor as the weighting factors of the two results predicted by GT and LRA respectively to find the final result, thus calculating the vehicle＇s traveling time. The method also considers such factors as dwell time, thus making the prediction more accurate.展开更多
The purpose of this research was to determine whether the Linear Regression Analysis can be effectively applied to the prioritization of defense-in-depth security tools and procedures to reduce cyber threats during th...The purpose of this research was to determine whether the Linear Regression Analysis can be effectively applied to the prioritization of defense-in-depth security tools and procedures to reduce cyber threats during the Global Corona Virus Pandemic. The way this was determined or methods used in this study consisted of scanning 20 peer reviewed Cybersecurity Articles from prominent Cybersecurity Journals for a list of defense in depth measures (tools and procedures) and the threats that those measures were designed to reduce. The methods further involved using the Likert Scale Model to create an ordinal ranking of the measures and threats. The defense in depth tools and procedures were then compared to see whether the Likert scale and Linear Regression Analysis could be effectively applied to prioritize and combine the measures to reduce pandemic related cyber threats. The results of this research reject the H0 null hypothesis that Linear Regression Analysis does not affect the relationship between the prioritization and combining of defense in depth tools and procedures (independent variables) and pandemic related cyber threats (dependent variables).展开更多
In this paper we firstly select main factors relating to urbanization level of Xiantao District in Hubei Province by main element, then, make model of urbanization level by analysis of multiple liner regression, and l...In this paper we firstly select main factors relating to urbanization level of Xiantao District in Hubei Province by main element, then, make model of urbanization level by analysis of multiple liner regression, and lastly predict its urbanization level展开更多
Four samples from a Permian reservoir in the Ordos Basin of North China were separated into twelve fractions in grain sizes of 〈0.5, 0.5-1 and 1-2 μm. Using the ^40Ar-^39Ar step-heating method, all of the fractions ...Four samples from a Permian reservoir in the Ordos Basin of North China were separated into twelve fractions in grain sizes of 〈0.5, 0.5-1 and 1-2 μm. Using the ^40Ar-^39Ar step-heating method, all of the fractions essentially yielded plateau ages ranging from 172.5 to 217.1 Ma. These scattered plateau ages might not have been obtained from pure diagenetic illites but from mixed clay minerals, although the samples were disaggregated using a gentle freeze-thaw cycle to free them of non-clay minerals. A regional thermal event, as suggested by several proxies, led to intensive iHitization as a distinct diagenetic process when the Yanshanian Movement triggered magmatism around the entire North China Block during the Jurassic to Cretaceous. Thermal illites formed during a short time period, whereas detrital illites came from various sources. The scattered plateau ages could have resulted from mixed degassing of thermal and detrital illites. Within one sample, the plateau ages decrease with the diminution of grain sizes, but it is difficult to extrapolate to the detrital-illite-free ages. Because the plateau age is a mixture of ages for thermal and detrital illites, this regression analysis studies the dependence of the plateau ages on the synthetic values of contents and ages of detrital illites instead of on the grain sizes. Comparing the samples to one another, the plateau ages show the same trend among the different grain sizes. Weighted by the contents and ages of detrital illites, linear regression analysis revealed the relationship between the plateau ages and the relative weight proportions. Based on iterated calculations, a thermal event age and a set of weight proportions were derived. The regressed thermal event age is 163.3±1.6 Ma, which coincides with regional thermal activities and links to gas accumulation.展开更多
Strong sensitivity of satellite microwave remote sensing to the change of surface dielectric properties,as well as the insensitivity to air pollution and solar illumination effects,makes it very suitable for monitorin...Strong sensitivity of satellite microwave remote sensing to the change of surface dielectric properties,as well as the insensitivity to air pollution and solar illumination effects,makes it very suitable for monitoring freeze-thaw conditions.The freeze-thaw cycle changes in the Qinghai-Xizang Plateau have an important impact on the ecological environment and infrastructure.Based on the Scanning Multi-channel Microwave Radiometer(SMMR)and other sensors of microwave satellite,the freeze-thaw cycle data of permafrost in the Qinghai-Xizang Plateau in the past 40 years from 1981 to 2020 was obtained.The changes of soil freeze-thaw conditions in different seasons of 2020 and in the same season of 1990,2000,2010 and 2020 were compared,and the annual variation trend of soil freeze-thaw area in the four years was analyzed.Further,the linear regression analysis was carried out on the duration of soil freezing/thawing/transition and the interannual variation trend under different area conditions from 1981 to 2020.The results show that the freeze-thaw changes in different years are similar.In winter,it is mainly frozen for about 110 days.Spring and autumn are transitional periods,lasting for 170 days.In summer,it is mainly thawed for about 80 days.From 1981 to 2020,the freezing period and the average freezing area of the Qinghai-Xizang Plateau decreased at a rate of 0.22 days and 1986 km^(2) per year,respectively,while the thawing period and the average thawing area increased at a rate of 0.07 days and 3187 km^(2) per year,respectively.The research results provide important theoretical support for the ecological environment and permafrost protection of the Qinghai-Xizang Plateau.展开更多
This research talks about the radiator cooling system of the automobile engine,the radiator’ s fluidstructure interaction dynamics based on computational fluid dynamics( CFD) STAR-CCM+ software. The linear regression...This research talks about the radiator cooling system of the automobile engine,the radiator’ s fluidstructure interaction dynamics based on computational fluid dynamics( CFD) STAR-CCM+ software. The linear regression model of coolant determined by MATLAB software was imported into the user-defined field function of the software,using the standard K-Epsilon turbulence model to analyze temperature,pressure and velocity changes of the coolant in the radiator channel. In order to improve the efficiency of the radiator,it is necessary to analyze the structure of two kinds of heat sinks,and get better heat transfer effect.展开更多
In this article,it discusses the di£ferences in economic development between urban and rural areas and regions in our country from the perspective of education investment and fixed asset investment.Based on the p...In this article,it discusses the di£ferences in economic development between urban and rural areas and regions in our country from the perspective of education investment and fixed asset investment.Based on the provincial data of 31 provinces from 1999 to 2017 released by National Bureau of Statistics,it expends the Cobb-Douglas model and Lucas model,and analyses the data with multiple linear regression models.From the study,it finds that compared with investment in fixed assets,investment in education has a larger role in promoting economic development,which is more obvious in the underdeveloped central and western regions and rural areas.However,at the same time it needs to note that the positive effects of education investment will be restricted by the economic structure and policy environment,and education expenditure policies should also be implemented in accordance with time and local conditions.展开更多
Factors affecting bath water temperature model include the shape and size of a bath, people’s gesture, volume, individual temperature adaptation as well as body movement in the bath. In addition, the bathroom space, ...Factors affecting bath water temperature model include the shape and size of a bath, people’s gesture, volume, individual temperature adaptation as well as body movement in the bath. In addition, the bathroom space, ambient temperature and bath materials will also affect changes of the water temperature to a certain extent. In this paper, the cooling function and linear regression method are used and the MATLAB software is also used to simulate the model of water temperature, alkaline bath foams that obtained can accelerate changes in water temperature.展开更多
Spatio-temporal assessment of the above ground biomass （AGB） is a cumbersome task due to the difficulties associated with the measurement of different tree parameters such as girth at breast height and height of tre...Spatio-temporal assessment of the above ground biomass （AGB） is a cumbersome task due to the difficulties associated with the measurement of different tree parameters such as girth at breast height and height of trees. The present research was conducted in the campus of Birla Institute of Technology, Mesra, Ranchi, India, which is predomi- nantly covered by Sal （Shorea robusta C. F. Gaertn）. Two methods of regression analysis was employed to determine the potential of remote sensing parameters with the AGB measured in the field such as linear regression analysis between the AGB and the individual bands, principal components （PCs） of the bands, vegetation indices （VI）, and the PCs of the VIs respectively and multiple linear regression （MLR） analysis be- tween the AGB and all the variables in each category of data. From the linear regression analysis, it was found that only the NDVI exhibited regression coefficient value above 0.80 with the remaining parameters showing very low values. On the other hand, the MLR based analysis revealed significantly improved results as evidenced by the occurrence of very high correlation coefficient values of greater than 0.90 determined between the computed AGB from the MLR equations and field-estimated AGB thereby ascertaining their superiority in providing reliable estimates of AGB. The highest correlation coefficient of 0.99 is found with the MLR involving PCs of VIs.展开更多
目的探讨50岁及以上人群卫生保健服务满意度和生活质量之间的关系。方法利用世界卫生组织(World Health Organization,WHO)全球老龄化与成人健康研究中国项目基线调查资料,选取我国8个省/直辖市15050名50岁及以上的中老年人,使用全球老...目的探讨50岁及以上人群卫生保健服务满意度和生活质量之间的关系。方法利用世界卫生组织(World Health Organization,WHO)全球老龄化与成人健康研究中国项目基线调查资料,选取我国8个省/直辖市15050名50岁及以上的中老年人,使用全球老龄化与成人健康研究问卷和WHO生活质量量表8项简化版评估卫生保健服务满意度和生活质量,并获取社会人口学及慢性病患病情况等信息,使用多元线性回归模型分析两者之间的关系并按居住地、性别和年龄组进行分层分析。结果研究共纳入研究对象13408人,平均年龄为(63.86±10.24)岁,对本市(区)提供的卫生保健服务感到非常满意的占4.16%,感到满意的占58.90%,感到一般的占30.81%,感到不满意的占5.69%,感到非常不满意的占0.44%。研究对象生活质量得分为(40.25±15.56)分,多元线性回归分析显示研究对象的卫生保健服务满意度越高,生活质量越好(P<0.001)。在分层分析中,该关联在不同居住地区、不同性别以及不同年龄组中均有统计学意义(P<0.001)。结论50岁及以上的人群中,较高的卫生保健服务满意度和较高的生活质量相关。展开更多
Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·...Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·Mg2+ or HCO3--Mg2+·Ca2+; SO42--Ca2+ and SO42--Ca2+·Mg2+; Cl--Ca2+; and CO32--Na+. The deteriorations of groundwater quality due to the increase of TDS, NO3-+ NO2-(as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl-and NO3-ions and weak negative correlations between the depth of water table and Ca2+, SO42-, Cl-and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2-and Mn2+ ions.展开更多
Landscape characters in estuarine regions generally controlled by tidal regimes and human activities like road construction.In this work,tidal channels and road construction in the Yellow River Delta(YRD)were extracte...Landscape characters in estuarine regions generally controlled by tidal regimes and human activities like road construction.In this work,tidal channels and road construction in the Yellow River Delta(YRD)were extracted by visual interpretation methods so as to decipher impacts of tidal channel development and road construction on landscape patch change during 1989–2016.Spatial distribution history of three wetlands,which covered by Phragmites australis(freshwater marsh,FM),Suaeda salsa(salt marsh,SM),and mudflats(MD)were also established.Results indicated that tidal channel,number,frequency,and fractal dimension were all the maximum in 2003,and the minimum in 1998,respectively.Road length,number,and density showed increasing trend during 1989–2016.MD were the predominant landscape type,followed by FM and SM during 1989-2016.Principal component analysis implied two extracted factors,F1 and F2,which could represent 91.93% of the total variations.F1 mainly proxied tidal channel development,while F2 represented road construction.A multiple linear regression analysis showed positive effects of both F1 and F2 on FM patch numbers and negative impacts on SM patch areaes with R^2 values of 0.416 and 0.599,respectively.Tidal channels were negatively related to MD patch numbers,while roads were positively related to that.In any case,road construction showed larger impacts on landscape type shifting than that of tidal channel development in the YRD.展开更多
BACKGROUND： Stroke is the leading cause of death and long-term disability. This study was undertaken to investigate the factors influencing daily activities of patients with cerebral infarction so as to take interven...BACKGROUND： Stroke is the leading cause of death and long-term disability. This study was undertaken to investigate the factors influencing daily activities of patients with cerebral infarction so as to take interventional measures earlier to improve their daily activities.METHODS： A total of 149 patients with first-episode cerebral infarction were recruited into this prospective study. They were admitted to the Encephalopathy Center, Department of Neurology, the First Affiliated Hospital of Wenzhou Medical College in Zhejiang Province from August 2008 to December 2008. The baseline characteristics of the patients and cerebral infarction risk factors on the first day of admission were recorded. White blood cell （WBC） count, plasma glucose （PG）, and many others of laboratory targets were collected in the next morning. Barthel index （BI） was calculated at 2 weeks and 3 months respectively after onset of the disease at the outpatient clinic or by telephone call. Lung infection, urinary tract infection and atrial fibrillation if any were recorded on admission. The National Institute of Health Stroke Scale （NIHSS） scores and the GCS scores were recorded within 24 hours on and after admission, at the second week, and at the third month after the onset of cerebral infarction respectively.RESULTS： The factors of BI at 2 weeks and 3 months after onset were the initial PG level, WBC count and initial NIHSS scores. Besides, urinary tract infection on admission was also the factor for BI at 3 months.CONCLUSION： Active measures should be taken to control these factors to improve the daily activities of patients with cerebral infarction.展开更多
Wetlands are classified as essential and valuable components of the ecosystem. Wetlands are significant for ecosystem services such as nutrient cycles, soil formation and water treatment. Nearly half of the world’s w...Wetlands are classified as essential and valuable components of the ecosystem. Wetlands are significant for ecosystem services such as nutrient cycles, soil formation and water treatment. Nearly half of the world’s wetlands have vanished in the last century because of anthropogenic activities, agricultural land use, and urban development, one of such places that are faced with the challenges of sustainability is the wetland habitats. This study aimed at assessing the spatial temporal characteristics of wetlands ecosystem in the Niger Delta Region of Nigeria from 1986-2016. The secondary data include raw satellite imageries obtained from the archive of the United States Geological Survey and Earth Explorer. The data set includes a notable period of four years landsat images for, 1986, 1996, 2006 and 2016. The maps were projected using Universal Transverse Mercator (UTM) projection system and datum WGS 84 of zone 32. Satellite images of the study area were acquired from the United States Geological Survey (USGS). The USGS uses the LandSat5 Thematic Mapper (TM) Landsat7 Thematic Mapper, Enhanced Thematic Mapper (ETM+), Thermal Infrared Sensor (TIRS) and Landsa8 Operational Land Imager (OLI) to generate high resolution images that are useful for this type of study. The satellite imageries were also analyzed using GIS and Remote Sensing techniques by computing of Normalized Differential Vegetation Index (NDVI) values for the entire study area by conversion of spectral reflectance values into NDVI values.<span> The satellite images covering the area were acquired and analyzed using ArcGIS10.6. A total area of 25</span></span><span style="font-family:"">,</span><span style="font-family:"">053.93</span><span style="font-family:""> (km<sup>2</sup>)<span> was delineated in the study area. After processing the imagery, five land use/land cover (LULC) classes were developed in ArcGIS environment, such as </span>Built-up area, Fallow land, Vegetation, Wetland and Waterbody.</span><span style="font-family:""> </span><span style="font-family:"">This study concludes that changes in wetland landscape patterns will produce profound impacts in urban areas where there<span style="color:red;"> </span>are rapid anthropogenic activities. Anova table showed a huge significant relationship between time and vegetation decrease across the study area at 0.027 which is less than 0.05 significance level. Wetlands warming and drying will cause the shrinking and reduction of wetland in sizes from accelerated wetland degradation. Therefore, there is an interaction and mutual influence between dynamic changes of wetland landscape patterns and other land use classes.展开更多
In this paper,we first give the solution concept of the fuzzy matrix equation =. Secondly,we discuss the property of the solution and give the method of solving the fuzzy matrix equation A=. Finally,we present an appl...In this paper,we first give the solution concept of the fuzzy matrix equation =. Secondly,we discuss the property of the solution and give the method of solving the fuzzy matrix equation A=. Finally,we present an application of solving fuzzy matrix equation A= to the fuzzy linear regression analysis,establish a new model of fuzzy linear regression,and introduce a new method of estimating parameters.展开更多
Aiming at deep roadway anchorage solids, laboratory similar model tests were used to reveal the mechanical properties of anchorage solids with different anchorage lengths under the coupling effect of temperature and p...Aiming at deep roadway anchorage solids, laboratory similar model tests were used to reveal the mechanical properties of anchorage solids with different anchorage lengths under the coupling effect of temperature and pressure, and SPSS statistical analysis software was used to conduct linear regression analysis of the ultimate anchorage force obtained from the tests. The results show that: through multiple linear regression analysis, the influence degree of temperature and pressure coupling on the ultimate anchorage force is arranged in order of anchoring length > surrounding rock strength > temperature > side pressure coefficient, and the linear regression equation of the model is obtained. Compared with the linear regression equation of simulation results, the model has a high explanatory ability.展开更多
The purpose of this research was to develop a new approach in determination of overhaul and maintenance cost of loading equipment in surface mining. Two statistical models including univariate exponential regression (...The purpose of this research was to develop a new approach in determination of overhaul and maintenance cost of loading equipment in surface mining. Two statistical models including univariate exponential regression (UER) and multivariate linear regression (MLR) were used in this study. Loading equipment parameters such as bucket capacity, machine weight, engine power, boom length, digging depth, and dumping height were considered as variables. The results obtained by models and mean absolute error rate indicate that these models can be applied as the useful tool in determination of overhaul and maintenance cost of loading equipment. The results of this study can be used by the decision-makers for the specific surface mining operations.展开更多
Objective To investigate the correlation between the clinical features and endoscopic ultrasound-guided portal pressure gradient(EUS-PPG)in patients with cirrhosis.Methods A total of 148 patients with cirrhosis and po...Objective To investigate the correlation between the clinical features and endoscopic ultrasound-guided portal pressure gradient(EUS-PPG)in patients with cirrhosis.Methods A total of 148 patients with cirrhosis and portal hypertension who underwent EUS-PPG measurement at the Third Xiangya Hospital of Central South University from March 15,2022 to June 20,2023 were selected.The clinical data of patients collected before EUS-PPG measurement were analyzed.Variations in the EUS-PPG across different clinical data subgroups were analyzed.Multivariate linear regression analysis was used to explore the independent factors influencing EUS-PPG.Results The EUS-PPG was significantly elevated in patients exhibiting red signs(16.62±5.33 mmHg VS 13.44±5.34 mmHg,t=3.616,P<0.001),gastroesophageal varices(15.78±5.30 mmHg VS 9.70±4.77 mmHg,t=4.247,P<0.001),hepatic encephalopathy(20.83±7.52 mmHg VS 14.92±5.35 mmHg,t=2.606,P=0.010),thrombocytopenia(15.66±5.39 mmHg VS 13.29±5.83mmHg,t=2.136,P=0.034),hypoproteinemia(16.13±5.86 mmHg VS 14.12±5.03 mmHg,t=2.230,P=0.027),and an increased international normalized ratio(16.25±6.00 mmHg VS 14.40±5.11mmHg,t=2.022,P=0.045).Conversely,the EUS-PPG was significantly reduced in patients with a history of splenectomy and devascularization(13.17±5.88mmHgVS15.73±5.34mmHg,t=-2.379,P=0.019).The EUS-PPG in patients with varying degrees of ascites(no VS slight VS moderate or severe:13.40±5.48 mmHg VS 15.90±5.49 mmHg VS 16.69±5.17 mmHg,F=5.188,P=0.007)and different Child-Pugh classifications(A VS B VS C:14.07±5.05 mmHg VS 15.69±5.74 mmHg VS 17.64±5.99 mmHg,F=3.066,P=0.049)increased gradually.Multivariable linear regression analysis showed that red signs(β=2.44,t=2.732,P=0.007),gastroesophageal varices(β=4.45,t=2.990,P=0.003),ascites(β=1.75,t=2.368,P=0.019),and hepatic encephalopathy(β=5.82,t=2.644,P=0.009)were independentftactors fortheelevated1EUS-PPG.Conclusion There is a significant correlation between EUS-PPG and the clinical features related to the severity of cirrhotic portal hypertension,which indicates the feasibility of EUS-PPG in evaluating cirrhotic portal hypertension.展开更多
Many per-and poly-fluoroalkyl substances(PFAS)studies in environmental media have been conducted in heavily industrialized and densely populated areas.However,there has been limited research on legacy and emerging PFA...Many per-and poly-fluoroalkyl substances(PFAS)studies in environmental media have been conducted in heavily industrialized and densely populated areas.However,there has been limited research on legacy and emerging PFAS contamination in cold and arid regions.In the present study,we investigated the concentrations of 30 PFAS compounds in the surface water and sediment of Hulun Lake and its inflowing rivers.The main components in water were short chain perfluoroalkyl carboxylic acids(PFCAs)in both Hulun Lake(33.57%)and its inflowing rivers(30.47%).However,long chain perfluoroalkane sulfonates(PFSAs)and long chain PFCAs accounted for more than half of the total PFAS content in sediment.Total PFAS concentrations(∑_(30)PFAS)ranged from 3.67 to 8.84 ng/L in water,and 0.97-1.73 mg/kg in sediment.Significant spatial differences were apparent between Hulun Lake and its inflowing rivers in both water and sediment samples.Source apportionment revealed that wastewater,aqueous film forming foams,textiles and paper-based food packaging,and paper products and cosmetics were the primary sources of PFAS.The partitioning coefficients of PFCAs were dependent on the carbon chain length.Temperature,conductivity,pH,salinity,chemical oxygen demand,total phosphorus(TP),total nitrogen(TN),As,and oxidation-reduction potential were the main influencing factors in water.Heavy metals(Co,Pb,Cu,Ni,Hg,Cd,and As),TP,salinity,and pH were positively correlated with the PFAS concentration in sediment.Furthermore,Hailar River contributed the majority(99.74%,~15.05 kg/year)of the PFAS mass flux.This is the first study showing PFAS contamination in Hulun Lake and the results suggest that long term monitoring is needed for the effective control of PFAS pollution in this typical cold and arid region of China.展开更多
Objective To investigate the correlation between serum plasmamembranevesicle-associated protein(PLVAP)levels and metabolism-associated fatty liver disease(MAFLD)in patients with T2DM.Methods A total of 255 patients wi...Objective To investigate the correlation between serum plasmamembranevesicle-associated protein(PLVAP)levels and metabolism-associated fatty liver disease(MAFLD)in patients with T2DM.Methods A total of 255 patients with type 2 diabetes mellitus(T2DM)treated in Gansu Provincial Hospital from September 2023 to March 2024 were selected in this study,and were divided into T2DM alone group(n=141)and the T2DM combined with MAFLD group(n=114)according to whether they were combined with MAFLD or not.Spearman correlation analysis was used to analyze the correlation between serum PLVAP and other indexes,multiple linear regression analysis was used to analyze the influencing factors of serum PLVAP,and Logistic regression analysis was used to analyze the influencing factors of MAFLD in T2DM patients.The early diagnostic value of serum PLVAP on MAFLD in patients with T2DM by analyzing the receiver's operating characteristics(ROC)curve.Results Compared with the MAFLD group,BMI,WC,FPG,C-P,HOMA-IR,TG,AST,ALT,GGT,hepatic steatosis index(HSI)and phytohaemagglutinin-like oxidized low-density lipoprotein receptor 1(LOX-1)were decreased in the T2DM group(P<0.05).DM duration,,HDL-C,AST/ALT and PLVAP were elevated(P<0.05).Spearman correlation analysis showed that PLVAP was positively correlated with AST/ALT(P<0.05)and negatively correlated with WC,DBP,C-P,ALT,GGT and HSI(P<0.05).Multiple linear regression analysis showed that WC was an influencing factor for PLVAP.Logistic regression analysis showed that DM duration,WC,TG,PLVAP,LOX-1 were influencing factors for MAFLD.Analysis of the subjects'work characteristics(ROC)curve showed that the area under the ROC curve was 0.785,with a sensitivity of 81.6%and a specificity of 67.4%.Conclusion Reduced PLVAP is a risk factor for comorbid MAFLD in patients with T2DM and is important for predicting the co-existence of MAFLD in patients with T2DM.展开更多
基金the National Natural Science Foundation of China (No. 50575145)the National High Technology Research and Development Program (863) of China(Nos. 2006AA04Z432 and 2007AA04Z419)
文摘Vehicle traveling time prediction is an important part of the research of intelligent transportation system. By now, there have been various kinds of methods for vehicle traveling time prediction. But few consider both aspects of time and space. In this paper, a vehicle traveling time prediction method based on grey theory （GT） and linear regression analysis （LRA） is presented. In aspects of time, we use the history data sequence of bus speed on a certain road to predict the future bus speed on that road by GT. And in aspects of space, we calculate the traffic affecting factors between various roads by LRA. Using these factors we can predict the vehicle＇s speed at the lower road if the vehicle＇s speed at the current road is known. Finally we use time factor and space factor as the weighting factors of the two results predicted by GT and LRA respectively to find the final result, thus calculating the vehicle＇s traveling time. The method also considers such factors as dwell time, thus making the prediction more accurate.
文摘The purpose of this research was to determine whether the Linear Regression Analysis can be effectively applied to the prioritization of defense-in-depth security tools and procedures to reduce cyber threats during the Global Corona Virus Pandemic. The way this was determined or methods used in this study consisted of scanning 20 peer reviewed Cybersecurity Articles from prominent Cybersecurity Journals for a list of defense in depth measures (tools and procedures) and the threats that those measures were designed to reduce. The methods further involved using the Likert Scale Model to create an ordinal ranking of the measures and threats. The defense in depth tools and procedures were then compared to see whether the Likert scale and Linear Regression Analysis could be effectively applied to prioritize and combine the measures to reduce pandemic related cyber threats. The results of this research reject the H0 null hypothesis that Linear Regression Analysis does not affect the relationship between the prioritization and combining of defense in depth tools and procedures (independent variables) and pandemic related cyber threats (dependent variables).
文摘In this paper we firstly select main factors relating to urbanization level of Xiantao District in Hubei Province by main element, then, make model of urbanization level by analysis of multiple liner regression, and lastly predict its urbanization level
基金supported by the National Natural Science Foundation of China(No.40572081)the Chinese Academy of Sciences(No.KZCX1-SW-18)
文摘Four samples from a Permian reservoir in the Ordos Basin of North China were separated into twelve fractions in grain sizes of 〈0.5, 0.5-1 and 1-2 μm. Using the ^40Ar-^39Ar step-heating method, all of the fractions essentially yielded plateau ages ranging from 172.5 to 217.1 Ma. These scattered plateau ages might not have been obtained from pure diagenetic illites but from mixed clay minerals, although the samples were disaggregated using a gentle freeze-thaw cycle to free them of non-clay minerals. A regional thermal event, as suggested by several proxies, led to intensive iHitization as a distinct diagenetic process when the Yanshanian Movement triggered magmatism around the entire North China Block during the Jurassic to Cretaceous. Thermal illites formed during a short time period, whereas detrital illites came from various sources. The scattered plateau ages could have resulted from mixed degassing of thermal and detrital illites. Within one sample, the plateau ages decrease with the diminution of grain sizes, but it is difficult to extrapolate to the detrital-illite-free ages. Because the plateau age is a mixture of ages for thermal and detrital illites, this regression analysis studies the dependence of the plateau ages on the synthetic values of contents and ages of detrital illites instead of on the grain sizes. Comparing the samples to one another, the plateau ages show the same trend among the different grain sizes. Weighted by the contents and ages of detrital illites, linear regression analysis revealed the relationship between the plateau ages and the relative weight proportions. Based on iterated calculations, a thermal event age and a set of weight proportions were derived. The regressed thermal event age is 163.3±1.6 Ma, which coincides with regional thermal activities and links to gas accumulation.
基金National Natural Science foundation of China(No.42271432)Foundation of Shanxi Vocational University of Engineering Science and Technology(No.KJ 202426).
文摘Strong sensitivity of satellite microwave remote sensing to the change of surface dielectric properties,as well as the insensitivity to air pollution and solar illumination effects,makes it very suitable for monitoring freeze-thaw conditions.The freeze-thaw cycle changes in the Qinghai-Xizang Plateau have an important impact on the ecological environment and infrastructure.Based on the Scanning Multi-channel Microwave Radiometer(SMMR)and other sensors of microwave satellite,the freeze-thaw cycle data of permafrost in the Qinghai-Xizang Plateau in the past 40 years from 1981 to 2020 was obtained.The changes of soil freeze-thaw conditions in different seasons of 2020 and in the same season of 1990,2000,2010 and 2020 were compared,and the annual variation trend of soil freeze-thaw area in the four years was analyzed.Further,the linear regression analysis was carried out on the duration of soil freezing/thawing/transition and the interannual variation trend under different area conditions from 1981 to 2020.The results show that the freeze-thaw changes in different years are similar.In winter,it is mainly frozen for about 110 days.Spring and autumn are transitional periods,lasting for 170 days.In summer,it is mainly thawed for about 80 days.From 1981 to 2020,the freezing period and the average freezing area of the Qinghai-Xizang Plateau decreased at a rate of 0.22 days and 1986 km^(2) per year,respectively,while the thawing period and the average thawing area increased at a rate of 0.07 days and 3187 km^(2) per year,respectively.The research results provide important theoretical support for the ecological environment and permafrost protection of the Qinghai-Xizang Plateau.
基金supported by the Ninth Batch of the Top Six Talents of Jiangsu Province(2012-ZBZZ-047)
文摘This research talks about the radiator cooling system of the automobile engine,the radiator’ s fluidstructure interaction dynamics based on computational fluid dynamics( CFD) STAR-CCM+ software. The linear regression model of coolant determined by MATLAB software was imported into the user-defined field function of the software,using the standard K-Epsilon turbulence model to analyze temperature,pressure and velocity changes of the coolant in the radiator channel. In order to improve the efficiency of the radiator,it is necessary to analyze the structure of two kinds of heat sinks,and get better heat transfer effect.
文摘In this article,it discusses the di£ferences in economic development between urban and rural areas and regions in our country from the perspective of education investment and fixed asset investment.Based on the provincial data of 31 provinces from 1999 to 2017 released by National Bureau of Statistics,it expends the Cobb-Douglas model and Lucas model,and analyses the data with multiple linear regression models.From the study,it finds that compared with investment in fixed assets,investment in education has a larger role in promoting economic development,which is more obvious in the underdeveloped central and western regions and rural areas.However,at the same time it needs to note that the positive effects of education investment will be restricted by the economic structure and policy environment,and education expenditure policies should also be implemented in accordance with time and local conditions.
文摘Factors affecting bath water temperature model include the shape and size of a bath, people’s gesture, volume, individual temperature adaptation as well as body movement in the bath. In addition, the bathroom space, ambient temperature and bath materials will also affect changes of the water temperature to a certain extent. In this paper, the cooling function and linear regression method are used and the MATLAB software is also used to simulate the model of water temperature, alkaline bath foams that obtained can accelerate changes in water temperature.
文摘Spatio-temporal assessment of the above ground biomass （AGB） is a cumbersome task due to the difficulties associated with the measurement of different tree parameters such as girth at breast height and height of trees. The present research was conducted in the campus of Birla Institute of Technology, Mesra, Ranchi, India, which is predomi- nantly covered by Sal （Shorea robusta C. F. Gaertn）. Two methods of regression analysis was employed to determine the potential of remote sensing parameters with the AGB measured in the field such as linear regression analysis between the AGB and the individual bands, principal components （PCs） of the bands, vegetation indices （VI）, and the PCs of the VIs respectively and multiple linear regression （MLR） analysis be- tween the AGB and all the variables in each category of data. From the linear regression analysis, it was found that only the NDVI exhibited regression coefficient value above 0.80 with the remaining parameters showing very low values. On the other hand, the MLR based analysis revealed significantly improved results as evidenced by the occurrence of very high correlation coefficient values of greater than 0.90 determined between the computed AGB from the MLR equations and field-estimated AGB thereby ascertaining their superiority in providing reliable estimates of AGB. The highest correlation coefficient of 0.99 is found with the MLR involving PCs of VIs.
文摘目的探讨50岁及以上人群卫生保健服务满意度和生活质量之间的关系。方法利用世界卫生组织(World Health Organization,WHO)全球老龄化与成人健康研究中国项目基线调查资料,选取我国8个省/直辖市15050名50岁及以上的中老年人,使用全球老龄化与成人健康研究问卷和WHO生活质量量表8项简化版评估卫生保健服务满意度和生活质量,并获取社会人口学及慢性病患病情况等信息,使用多元线性回归模型分析两者之间的关系并按居住地、性别和年龄组进行分层分析。结果研究共纳入研究对象13408人,平均年龄为(63.86±10.24)岁,对本市(区)提供的卫生保健服务感到非常满意的占4.16%,感到满意的占58.90%,感到一般的占30.81%,感到不满意的占5.69%,感到非常不满意的占0.44%。研究对象生活质量得分为(40.25±15.56)分,多元线性回归分析显示研究对象的卫生保健服务满意度越高,生活质量越好(P<0.001)。在分层分析中,该关联在不同居住地区、不同性别以及不同年龄组中均有统计学意义(P<0.001)。结论50岁及以上的人群中,较高的卫生保健服务满意度和较高的生活质量相关。
文摘Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·Mg2+ or HCO3--Mg2+·Ca2+; SO42--Ca2+ and SO42--Ca2+·Mg2+; Cl--Ca2+; and CO32--Na+. The deteriorations of groundwater quality due to the increase of TDS, NO3-+ NO2-(as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl-and NO3-ions and weak negative correlations between the depth of water table and Ca2+, SO42-, Cl-and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2-and Mn2+ ions.
基金Under the auspices of National Key Research and Development Project(No.2017YFC0505901)
文摘Landscape characters in estuarine regions generally controlled by tidal regimes and human activities like road construction.In this work,tidal channels and road construction in the Yellow River Delta(YRD)were extracted by visual interpretation methods so as to decipher impacts of tidal channel development and road construction on landscape patch change during 1989–2016.Spatial distribution history of three wetlands,which covered by Phragmites australis(freshwater marsh,FM),Suaeda salsa(salt marsh,SM),and mudflats(MD)were also established.Results indicated that tidal channel,number,frequency,and fractal dimension were all the maximum in 2003,and the minimum in 1998,respectively.Road length,number,and density showed increasing trend during 1989–2016.MD were the predominant landscape type,followed by FM and SM during 1989-2016.Principal component analysis implied two extracted factors,F1 and F2,which could represent 91.93% of the total variations.F1 mainly proxied tidal channel development,while F2 represented road construction.A multiple linear regression analysis showed positive effects of both F1 and F2 on FM patch numbers and negative impacts on SM patch areaes with R^2 values of 0.416 and 0.599,respectively.Tidal channels were negatively related to MD patch numbers,while roads were positively related to that.In any case,road construction showed larger impacts on landscape type shifting than that of tidal channel development in the YRD.
文摘BACKGROUND： Stroke is the leading cause of death and long-term disability. This study was undertaken to investigate the factors influencing daily activities of patients with cerebral infarction so as to take interventional measures earlier to improve their daily activities.METHODS： A total of 149 patients with first-episode cerebral infarction were recruited into this prospective study. They were admitted to the Encephalopathy Center, Department of Neurology, the First Affiliated Hospital of Wenzhou Medical College in Zhejiang Province from August 2008 to December 2008. The baseline characteristics of the patients and cerebral infarction risk factors on the first day of admission were recorded. White blood cell （WBC） count, plasma glucose （PG）, and many others of laboratory targets were collected in the next morning. Barthel index （BI） was calculated at 2 weeks and 3 months respectively after onset of the disease at the outpatient clinic or by telephone call. Lung infection, urinary tract infection and atrial fibrillation if any were recorded on admission. The National Institute of Health Stroke Scale （NIHSS） scores and the GCS scores were recorded within 24 hours on and after admission, at the second week, and at the third month after the onset of cerebral infarction respectively.RESULTS： The factors of BI at 2 weeks and 3 months after onset were the initial PG level, WBC count and initial NIHSS scores. Besides, urinary tract infection on admission was also the factor for BI at 3 months.CONCLUSION： Active measures should be taken to control these factors to improve the daily activities of patients with cerebral infarction.
文摘Wetlands are classified as essential and valuable components of the ecosystem. Wetlands are significant for ecosystem services such as nutrient cycles, soil formation and water treatment. Nearly half of the world’s wetlands have vanished in the last century because of anthropogenic activities, agricultural land use, and urban development, one of such places that are faced with the challenges of sustainability is the wetland habitats. This study aimed at assessing the spatial temporal characteristics of wetlands ecosystem in the Niger Delta Region of Nigeria from 1986-2016. The secondary data include raw satellite imageries obtained from the archive of the United States Geological Survey and Earth Explorer. The data set includes a notable period of four years landsat images for, 1986, 1996, 2006 and 2016. The maps were projected using Universal Transverse Mercator (UTM) projection system and datum WGS 84 of zone 32. Satellite images of the study area were acquired from the United States Geological Survey (USGS). The USGS uses the LandSat5 Thematic Mapper (TM) Landsat7 Thematic Mapper, Enhanced Thematic Mapper (ETM+), Thermal Infrared Sensor (TIRS) and Landsa8 Operational Land Imager (OLI) to generate high resolution images that are useful for this type of study. The satellite imageries were also analyzed using GIS and Remote Sensing techniques by computing of Normalized Differential Vegetation Index (NDVI) values for the entire study area by conversion of spectral reflectance values into NDVI values.<span> The satellite images covering the area were acquired and analyzed using ArcGIS10.6. A total area of 25</span></span><span style="font-family:"">,</span><span style="font-family:"">053.93</span><span style="font-family:""> (km<sup>2</sup>)<span> was delineated in the study area. After processing the imagery, five land use/land cover (LULC) classes were developed in ArcGIS environment, such as </span>Built-up area, Fallow land, Vegetation, Wetland and Waterbody.</span><span style="font-family:""> </span><span style="font-family:"">This study concludes that changes in wetland landscape patterns will produce profound impacts in urban areas where there<span style="color:red;"> </span>are rapid anthropogenic activities. Anova table showed a huge significant relationship between time and vegetation decrease across the study area at 0.027 which is less than 0.05 significance level. Wetlands warming and drying will cause the shrinking and reduction of wetland in sizes from accelerated wetland degradation. Therefore, there is an interaction and mutual influence between dynamic changes of wetland landscape patterns and other land use classes.
文摘In this paper,we first give the solution concept of the fuzzy matrix equation =. Secondly,we discuss the property of the solution and give the method of solving the fuzzy matrix equation A=. Finally,we present an application of solving fuzzy matrix equation A= to the fuzzy linear regression analysis,establish a new model of fuzzy linear regression,and introduce a new method of estimating parameters.
文摘Aiming at deep roadway anchorage solids, laboratory similar model tests were used to reveal the mechanical properties of anchorage solids with different anchorage lengths under the coupling effect of temperature and pressure, and SPSS statistical analysis software was used to conduct linear regression analysis of the ultimate anchorage force obtained from the tests. The results show that: through multiple linear regression analysis, the influence degree of temperature and pressure coupling on the ultimate anchorage force is arranged in order of anchoring length > surrounding rock strength > temperature > side pressure coefficient, and the linear regression equation of the model is obtained. Compared with the linear regression equation of simulation results, the model has a high explanatory ability.
文摘The purpose of this research was to develop a new approach in determination of overhaul and maintenance cost of loading equipment in surface mining. Two statistical models including univariate exponential regression (UER) and multivariate linear regression (MLR) were used in this study. Loading equipment parameters such as bucket capacity, machine weight, engine power, boom length, digging depth, and dumping height were considered as variables. The results obtained by models and mean absolute error rate indicate that these models can be applied as the useful tool in determination of overhaul and maintenance cost of loading equipment. The results of this study can be used by the decision-makers for the specific surface mining operations.
文摘Objective To investigate the correlation between the clinical features and endoscopic ultrasound-guided portal pressure gradient(EUS-PPG)in patients with cirrhosis.Methods A total of 148 patients with cirrhosis and portal hypertension who underwent EUS-PPG measurement at the Third Xiangya Hospital of Central South University from March 15,2022 to June 20,2023 were selected.The clinical data of patients collected before EUS-PPG measurement were analyzed.Variations in the EUS-PPG across different clinical data subgroups were analyzed.Multivariate linear regression analysis was used to explore the independent factors influencing EUS-PPG.Results The EUS-PPG was significantly elevated in patients exhibiting red signs(16.62±5.33 mmHg VS 13.44±5.34 mmHg,t=3.616,P<0.001),gastroesophageal varices(15.78±5.30 mmHg VS 9.70±4.77 mmHg,t=4.247,P<0.001),hepatic encephalopathy(20.83±7.52 mmHg VS 14.92±5.35 mmHg,t=2.606,P=0.010),thrombocytopenia(15.66±5.39 mmHg VS 13.29±5.83mmHg,t=2.136,P=0.034),hypoproteinemia(16.13±5.86 mmHg VS 14.12±5.03 mmHg,t=2.230,P=0.027),and an increased international normalized ratio(16.25±6.00 mmHg VS 14.40±5.11mmHg,t=2.022,P=0.045).Conversely,the EUS-PPG was significantly reduced in patients with a history of splenectomy and devascularization(13.17±5.88mmHgVS15.73±5.34mmHg,t=-2.379,P=0.019).The EUS-PPG in patients with varying degrees of ascites(no VS slight VS moderate or severe:13.40±5.48 mmHg VS 15.90±5.49 mmHg VS 16.69±5.17 mmHg,F=5.188,P=0.007)and different Child-Pugh classifications(A VS B VS C:14.07±5.05 mmHg VS 15.69±5.74 mmHg VS 17.64±5.99 mmHg,F=3.066,P=0.049)increased gradually.Multivariable linear regression analysis showed that red signs(β=2.44,t=2.732,P=0.007),gastroesophageal varices(β=4.45,t=2.990,P=0.003),ascites(β=1.75,t=2.368,P=0.019),and hepatic encephalopathy(β=5.82,t=2.644,P=0.009)were independentftactors fortheelevated1EUS-PPG.Conclusion There is a significant correlation between EUS-PPG and the clinical features related to the severity of cirrhotic portal hypertension,which indicates the feasibility of EUS-PPG in evaluating cirrhotic portal hypertension.
基金supported by the National Science Fund for Distinguished Young Scholars(No.52125901)the Natural Science Foundation of Shandong(Grant No.ZR2023QE199).
文摘Many per-and poly-fluoroalkyl substances(PFAS)studies in environmental media have been conducted in heavily industrialized and densely populated areas.However,there has been limited research on legacy and emerging PFAS contamination in cold and arid regions.In the present study,we investigated the concentrations of 30 PFAS compounds in the surface water and sediment of Hulun Lake and its inflowing rivers.The main components in water were short chain perfluoroalkyl carboxylic acids(PFCAs)in both Hulun Lake(33.57%)and its inflowing rivers(30.47%).However,long chain perfluoroalkane sulfonates(PFSAs)and long chain PFCAs accounted for more than half of the total PFAS content in sediment.Total PFAS concentrations(∑_(30)PFAS)ranged from 3.67 to 8.84 ng/L in water,and 0.97-1.73 mg/kg in sediment.Significant spatial differences were apparent between Hulun Lake and its inflowing rivers in both water and sediment samples.Source apportionment revealed that wastewater,aqueous film forming foams,textiles and paper-based food packaging,and paper products and cosmetics were the primary sources of PFAS.The partitioning coefficients of PFCAs were dependent on the carbon chain length.Temperature,conductivity,pH,salinity,chemical oxygen demand,total phosphorus(TP),total nitrogen(TN),As,and oxidation-reduction potential were the main influencing factors in water.Heavy metals(Co,Pb,Cu,Ni,Hg,Cd,and As),TP,salinity,and pH were positively correlated with the PFAS concentration in sediment.Furthermore,Hailar River contributed the majority(99.74%,~15.05 kg/year)of the PFAS mass flux.This is the first study showing PFAS contamination in Hulun Lake and the results suggest that long term monitoring is needed for the effective control of PFAS pollution in this typical cold and arid region of China.
文摘Objective To investigate the correlation between serum plasmamembranevesicle-associated protein(PLVAP)levels and metabolism-associated fatty liver disease(MAFLD)in patients with T2DM.Methods A total of 255 patients with type 2 diabetes mellitus(T2DM)treated in Gansu Provincial Hospital from September 2023 to March 2024 were selected in this study,and were divided into T2DM alone group(n=141)and the T2DM combined with MAFLD group(n=114)according to whether they were combined with MAFLD or not.Spearman correlation analysis was used to analyze the correlation between serum PLVAP and other indexes,multiple linear regression analysis was used to analyze the influencing factors of serum PLVAP,and Logistic regression analysis was used to analyze the influencing factors of MAFLD in T2DM patients.The early diagnostic value of serum PLVAP on MAFLD in patients with T2DM by analyzing the receiver's operating characteristics(ROC)curve.Results Compared with the MAFLD group,BMI,WC,FPG,C-P,HOMA-IR,TG,AST,ALT,GGT,hepatic steatosis index(HSI)and phytohaemagglutinin-like oxidized low-density lipoprotein receptor 1(LOX-1)were decreased in the T2DM group(P<0.05).DM duration,,HDL-C,AST/ALT and PLVAP were elevated(P<0.05).Spearman correlation analysis showed that PLVAP was positively correlated with AST/ALT(P<0.05)and negatively correlated with WC,DBP,C-P,ALT,GGT and HSI(P<0.05).Multiple linear regression analysis showed that WC was an influencing factor for PLVAP.Logistic regression analysis showed that DM duration,WC,TG,PLVAP,LOX-1 were influencing factors for MAFLD.Analysis of the subjects'work characteristics(ROC)curve showed that the area under the ROC curve was 0.785,with a sensitivity of 81.6%and a specificity of 67.4%.Conclusion Reduced PLVAP is a risk factor for comorbid MAFLD in patients with T2DM and is important for predicting the co-existence of MAFLD in patients with T2DM.
