Zhao (2003a) first established a congruence for any odd prime p〉3, S(1,1,1 ;p)=-2Bp-3 (mod p), which holds when p=3 evidently. In this paper, we consider finite triple harmonic sum S(α,β, γ,ρ) (modp) is...Zhao (2003a) first established a congruence for any odd prime p〉3, S(1,1,1 ;p)=-2Bp-3 (mod p), which holds when p=3 evidently. In this paper, we consider finite triple harmonic sum S(α,β, γ,ρ) (modp) is considered for all positive integers α,β, γ. We refer to w=α+β+ γ as the weight of the sum, and show that if w is even, S(α,β, γ,ρ)=0 (mod p) for p≥w+3; if w is odd, S(α,β, γ,ρ)=-rBp-w (mod p) for p≥w, here r is an explicit rational number independent ofp. A congruence of Catalan number is obtained as a special case.展开更多
Conventional f-x prediction filtering methods are based on an autoregressive model. The error section is first computed as a source noise but is removed as additive noise to obtain the signal, which results in an assu...Conventional f-x prediction filtering methods are based on an autoregressive model. The error section is first computed as a source noise but is removed as additive noise to obtain the signal, which results in an assumption inconsistency before and after filtering. In this paper, an autoregressive, moving-average model is employed to avoid the model inconsistency. Based on the ARMA model, a noncasual prediction filter is computed and a self-deconvolved projection filter is used for estimating additive noise in order to suppress random noise. The 1-D ARMA model is also extended to the 2-D spatial domain, which is the basis for noncasual spatial prediction filtering for random noise attenuation on 3-D seismic data. Synthetic and field data processing indicate this method can suppress random noise more effectively and preserve the signal simultaneously and does much better than other conventional prediction filtering methods.展开更多
There is no doubt that the UHI (urban heat island) is a mounting problem in built-up environments, due to the energy retention by surface dense building materials, leading to increased temperatures, air pollution, a...There is no doubt that the UHI (urban heat island) is a mounting problem in built-up environments, due to the energy retention by surface dense building materials, leading to increased temperatures, air pollution, and energy consumption. Much of the earlier research on the UHI has used two-dimensional (2-D) information, such as land uses and the distribution of vegetation. In the case of homogeneous land uses, it is possible to predict surface temperatures with reasonable accuracy with 2-D information. However, three-dimensional (3-D) information is necessary to analyze more complex sites, including dense building clusters. In this research, 3-D building geometry information is combined with 2-D urban surface information to examine the relationship between urban characteristics and temperature. The research includes the following stages: (1) estimating urban temperature; (2) developing a 3-D city model; (3) generating geometric parameters; and (4) conducting statistical analyses using both linear and non-linear regression models. The implications of the results are discussed, providing guidelines for policies aiming to reduce the UHI.展开更多
The cost and safety of geotechnical engineering are highly depending on the accuracy of soil shear strength parameters.There are three methods often used to estimate soil shear strength parameters,i.e.,moment method,3...The cost and safety of geotechnical engineering are highly depending on the accuracy of soil shear strength parameters.There are three methods often used to estimate soil shear strength parameters,i.e.,moment method,3-sigma rule and linear regression method.In this study,the accuracy of these three methods is compared.Traditional linear regression method(LRM)can only offer the mean of shear strength parameters.Some engineers misuse the standard error of shear strength indexes as the standard deviations.Such misuse may highly underestimate the uncertainty and induce high risk to the geotechnical design.A modified LRM is proposed to determine both the mean and variance of shear strength parameters.The moment method,three-sigma rule and LRM are used to analyze the tri-axial test data in Xiaolangdi Hydraulic Project and three numerical shear strength tests.The results demonstrate that:1)The modified LRM can offer the most accurate estimation to shear strength parameters;2)A dimensionless formula is much preferred in LRM rather than a dimensional formula.The stress ratio formula is much better than stress relation in the shear strength parameter analysis.The proposed method is applicable to shear strength parameter analysis for tri-axial test data,direct shear test and the un-drained shear strength test of stratified clay.展开更多
Regression analysis is often formulated as an optimization problem with squared loss functions. Facing the challenge of the selection of the proper function class with polynomial smooth techniques applied to support v...Regression analysis is often formulated as an optimization problem with squared loss functions. Facing the challenge of the selection of the proper function class with polynomial smooth techniques applied to support vector regression models, this study takes cubic spline interpolation to generate a new polynomial smooth function |×|ε^ 2, in g-insensitive support vector regression. Theoretical analysis shows that Sε^2 -function is better than pε^2 -function in properties, and the approximation accuracy of the proposed smoothing function is two order higher than that of classical pε^2 -function. The experimental data shows the efficiency of the new approach.展开更多
A quantitative structure–activity relationship(QSAR) was performed to analyze antimalarial activities against the D10 strains of Plasmodium falciparum of triazole-linked chalcone and dienone hybrid derivatives using ...A quantitative structure–activity relationship(QSAR) was performed to analyze antimalarial activities against the D10 strains of Plasmodium falciparum of triazole-linked chalcone and dienone hybrid derivatives using partial least squares regression coupled with stepwise forward–backward variable selection method. QSAR analyses were performed on the available IC50 D10 strains of Plasmodium falciparum data based on theoretical molecular descriptors. The QSAR model developed gave good predictive correlation coefficient(r2) of 0.8994, significant cross validated correlation coefficient(q2) of 0.7689, r2 for external test set)(2predr of 0.8256, coefficient of correlation of predicted data set)(2sepred,r of 0.3276. The model shows that antimalarial activity is greatly affected by donor and electron-withdrawing substituents. The study implicates that chalcone and dienone rings should have strong donor and electron-withdrawing substituents as they increase the activity of chalcone. Results show that the predictive ability of the model is satisfactory, and it can be used for designing similar group of antimalarial compounds. The findings derived from this analysis along with other molecular modeling studies will be helpful in designing of the new potent antimalarial activity of clinical utility.展开更多
AIM: To investigate the association between metabolic syndrome (NetS) and the development of gallstone disease (GSD). METHODS: A cross-sectional study was conducted in 7570 subjects (4978 men aged 45.0:1:8.8 ...AIM: To investigate the association between metabolic syndrome (NetS) and the development of gallstone disease (GSD). METHODS: A cross-sectional study was conducted in 7570 subjects (4978 men aged 45.0:1:8.8 years, and 2592 women aged 45.3:1:9.5 years) enrolled from the physical check-up center of the hospital. The subjects included 918 patients with gallstones (653 men and 265 women) and 6652 healthy controls (4325 men and 2327 women) without gallstones. Body mass index (BII), waist circumference, blood pressure, fasting plasma glucose (FPG) and serum lipids and lipoproteins levels were measured. Colorimetric method was used to measure cholesterol, high-density lipoprotein cho- lesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Dextrose oxidizing enzyme method was used to measure FPG. Subjects were asked to complete a questionnaire that enquired about the information on demographic data, age, gender, histories of diabetes mellitus, hypertension, and chronic liver disease and so on. Metabolic syndrome was diagnosed according to the Adult Treatment Panel HI (ATP ]3) criteria. Gall- stones were defined by the presence of strong intralu- minal echoes that were gravity-dependent or attenu- ated ultrasound transmission. RESULTS: Among the 7570 subjects, the prevalence of the gallstone disease was 12.1% (13.1% in men and 10.2% in women). BMI, waist circumference, systolic blood pressure, diastolic blood pressure, fasting blood glucose and serum triglyceride (TG) in cases group were higher than in controls, while serum high-density lipid was lower than in controls. There were significant differences in the waist circumference, blood pressure, FPG and TG between cases and controls. In an age- adjusted logistic regression model, metabolic syndrome was associated with gallstone disease. The age-adjust- ed odds ratio of MetS for GSD in men was 1.29 [95% confidence interval (CI), 1.09-1.52; P = 0.0030], and 1.68 (95% CI, 1.26-2.25; P = 0.0004) in women; the overall age-adjusted odds ratio of NetS for GSD was 1.42 (95% CI, 1.23-1.64; P 〈 0.0001). The men with more metabolic disorders had a higher prevalence of gallstone disease, the trend had statistical significance (P 〈 0.0001). The presence of 5 components of the MetS increased the risk of gallstone disease by 3.4 times (P 〈 0.0001). The prevalence of GSD in women who had 5 components of NetS was 5 times higher than in those without Nets component. The more the components of Mets, the higher the prevalence of GSD (P 〈 0.0001). The presence of 5 components of the Mets increased the risk of gallstone disease by 4.0 times. CONCLUSION: GSD appears to be strongly associated with MetS, and the more the components of NetS, the higher the prevalence of GSD.展开更多
A new back-analysis method of ground stress is proposed with comprehensive consideration of influence of topography, geology and nonlinear physical mechanical properties of rock on ground stress. This method based on ...A new back-analysis method of ground stress is proposed with comprehensive consideration of influence of topography, geology and nonlinear physical mechanical properties of rock on ground stress. This method based on non-uniform rational B-spline (NURBS) technology provides the means to build a refined three-dimensional finite element model with more accurate meshing under complex terrain and geological conditions. Meanwhile, this method is a back-analysis of ground stress with combination of multivariable linear regression model and neural network (ANN) model. Firstly, the regression model is used to fit approximately boundary loads. Regarding the regressed loads as mean value, some sets of boundary loads with the same interval are constructed according to the principle of orthogonal design, to calculate the corresponding ground stress at the observation positions using finite element method. The results (boundary loads and the corresponding ground stress) are added to the samples for ANN training. And on this basis, an ANN model is established to implement higher precise back-analysis of initial ground stress. A practical application case shows that the relative error between the inversed ground stress and observed value is mostly less than 10 %, which can meet the need of engineering design and construction requirements.展开更多
Cascaded regression has been recently applied to reconstruct 3D faces from single 2D images directly in shape space, and has achieved state-of-the-art performance. We investigate thoroughly such cascaded regression ba...Cascaded regression has been recently applied to reconstruct 3D faces from single 2D images directly in shape space, and has achieved state-of-the-art performance. We investigate thoroughly such cascaded regression based 3D face reconstruction approaches from four perspectives that are not well been studied: (1) the impact of the number of 2D landmarks; (2) the impact of the number of 3D vertices; (3) the way of using standalone automated landmark detection methods; (4) the convergence property. To answer these questions, a simplified cascaded regression based 3D face reconstruction method is devised. This can be integrated with standalone automated landmark detection methods and reconstruct 3D face shapes that have the same pose and expression as the input face images, rather than normalized pose and expression. An effective training method is also proposed by disturbing the automatically detected landmarks. Comprehensive evaluation experiments have been carried out to compare to other 3D face reconstruction methods. The results not only deepen the understanding of cascaded regression based 3D face reconstruction approaches, but also prove the effectiveness of the proposed method.展开更多
基金Project (No. 10371107) supported by the National Natural Science Foundation of China
文摘Zhao (2003a) first established a congruence for any odd prime p〉3, S(1,1,1 ;p)=-2Bp-3 (mod p), which holds when p=3 evidently. In this paper, we consider finite triple harmonic sum S(α,β, γ,ρ) (modp) is considered for all positive integers α,β, γ. We refer to w=α+β+ γ as the weight of the sum, and show that if w is even, S(α,β, γ,ρ)=0 (mod p) for p≥w+3; if w is odd, S(α,β, γ,ρ)=-rBp-w (mod p) for p≥w, here r is an explicit rational number independent ofp. A congruence of Catalan number is obtained as a special case.
基金This research was financially supported by National Natural Science Foundation of China (Grant No. 40604016) and the National Hi-Tech Research and Development Program (863 Program) (Grants No. 2006AA09A102-09 and No. 2007AA06Z229).
文摘Conventional f-x prediction filtering methods are based on an autoregressive model. The error section is first computed as a source noise but is removed as additive noise to obtain the signal, which results in an assumption inconsistency before and after filtering. In this paper, an autoregressive, moving-average model is employed to avoid the model inconsistency. Based on the ARMA model, a noncasual prediction filter is computed and a self-deconvolved projection filter is used for estimating additive noise in order to suppress random noise. The 1-D ARMA model is also extended to the 2-D spatial domain, which is the basis for noncasual spatial prediction filtering for random noise attenuation on 3-D seismic data. Synthetic and field data processing indicate this method can suppress random noise more effectively and preserve the signal simultaneously and does much better than other conventional prediction filtering methods.
文摘There is no doubt that the UHI (urban heat island) is a mounting problem in built-up environments, due to the energy retention by surface dense building materials, leading to increased temperatures, air pollution, and energy consumption. Much of the earlier research on the UHI has used two-dimensional (2-D) information, such as land uses and the distribution of vegetation. In the case of homogeneous land uses, it is possible to predict surface temperatures with reasonable accuracy with 2-D information. However, three-dimensional (3-D) information is necessary to analyze more complex sites, including dense building clusters. In this research, 3-D building geometry information is combined with 2-D urban surface information to examine the relationship between urban characteristics and temperature. The research includes the following stages: (1) estimating urban temperature; (2) developing a 3-D city model; (3) generating geometric parameters; and (4) conducting statistical analyses using both linear and non-linear regression models. The implications of the results are discussed, providing guidelines for policies aiming to reduce the UHI.
基金Project(2017YFC0404803) supported by the National Key Research and Development Program of ChinaProject(51678040) supported by the National Natural Science Foundation of ChinaProject(8192034) supported by the Beijing Municipal Natural Science Foundation,China
文摘The cost and safety of geotechnical engineering are highly depending on the accuracy of soil shear strength parameters.There are three methods often used to estimate soil shear strength parameters,i.e.,moment method,3-sigma rule and linear regression method.In this study,the accuracy of these three methods is compared.Traditional linear regression method(LRM)can only offer the mean of shear strength parameters.Some engineers misuse the standard error of shear strength indexes as the standard deviations.Such misuse may highly underestimate the uncertainty and induce high risk to the geotechnical design.A modified LRM is proposed to determine both the mean and variance of shear strength parameters.The moment method,three-sigma rule and LRM are used to analyze the tri-axial test data in Xiaolangdi Hydraulic Project and three numerical shear strength tests.The results demonstrate that:1)The modified LRM can offer the most accurate estimation to shear strength parameters;2)A dimensionless formula is much preferred in LRM rather than a dimensional formula.The stress ratio formula is much better than stress relation in the shear strength parameter analysis.The proposed method is applicable to shear strength parameter analysis for tri-axial test data,direct shear test and the un-drained shear strength test of stratified clay.
基金Supported by Guangdong Natural Science Foundation Project(No.S2011010002144)Province and Ministry Production and Research Projects(No.2012B091100497,2012B091100191,2012B091100383)+1 种基金Guangdong Province Enterprise Laboratory Project(No.2011A091000046)Guangdong Province Science and Technology Major Project(No.2012A080103010)
文摘Regression analysis is often formulated as an optimization problem with squared loss functions. Facing the challenge of the selection of the proper function class with polynomial smooth techniques applied to support vector regression models, this study takes cubic spline interpolation to generate a new polynomial smooth function |×|ε^ 2, in g-insensitive support vector regression. Theoretical analysis shows that Sε^2 -function is better than pε^2 -function in properties, and the approximation accuracy of the proposed smoothing function is two order higher than that of classical pε^2 -function. The experimental data shows the efficiency of the new approach.
文摘A quantitative structure–activity relationship(QSAR) was performed to analyze antimalarial activities against the D10 strains of Plasmodium falciparum of triazole-linked chalcone and dienone hybrid derivatives using partial least squares regression coupled with stepwise forward–backward variable selection method. QSAR analyses were performed on the available IC50 D10 strains of Plasmodium falciparum data based on theoretical molecular descriptors. The QSAR model developed gave good predictive correlation coefficient(r2) of 0.8994, significant cross validated correlation coefficient(q2) of 0.7689, r2 for external test set)(2predr of 0.8256, coefficient of correlation of predicted data set)(2sepred,r of 0.3276. The model shows that antimalarial activity is greatly affected by donor and electron-withdrawing substituents. The study implicates that chalcone and dienone rings should have strong donor and electron-withdrawing substituents as they increase the activity of chalcone. Results show that the predictive ability of the model is satisfactory, and it can be used for designing similar group of antimalarial compounds. The findings derived from this analysis along with other molecular modeling studies will be helpful in designing of the new potent antimalarial activity of clinical utility.
文摘AIM: To investigate the association between metabolic syndrome (NetS) and the development of gallstone disease (GSD). METHODS: A cross-sectional study was conducted in 7570 subjects (4978 men aged 45.0:1:8.8 years, and 2592 women aged 45.3:1:9.5 years) enrolled from the physical check-up center of the hospital. The subjects included 918 patients with gallstones (653 men and 265 women) and 6652 healthy controls (4325 men and 2327 women) without gallstones. Body mass index (BII), waist circumference, blood pressure, fasting plasma glucose (FPG) and serum lipids and lipoproteins levels were measured. Colorimetric method was used to measure cholesterol, high-density lipoprotein cho- lesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Dextrose oxidizing enzyme method was used to measure FPG. Subjects were asked to complete a questionnaire that enquired about the information on demographic data, age, gender, histories of diabetes mellitus, hypertension, and chronic liver disease and so on. Metabolic syndrome was diagnosed according to the Adult Treatment Panel HI (ATP ]3) criteria. Gall- stones were defined by the presence of strong intralu- minal echoes that were gravity-dependent or attenu- ated ultrasound transmission. RESULTS: Among the 7570 subjects, the prevalence of the gallstone disease was 12.1% (13.1% in men and 10.2% in women). BMI, waist circumference, systolic blood pressure, diastolic blood pressure, fasting blood glucose and serum triglyceride (TG) in cases group were higher than in controls, while serum high-density lipid was lower than in controls. There were significant differences in the waist circumference, blood pressure, FPG and TG between cases and controls. In an age- adjusted logistic regression model, metabolic syndrome was associated with gallstone disease. The age-adjust- ed odds ratio of MetS for GSD in men was 1.29 [95% confidence interval (CI), 1.09-1.52; P = 0.0030], and 1.68 (95% CI, 1.26-2.25; P = 0.0004) in women; the overall age-adjusted odds ratio of NetS for GSD was 1.42 (95% CI, 1.23-1.64; P 〈 0.0001). The men with more metabolic disorders had a higher prevalence of gallstone disease, the trend had statistical significance (P 〈 0.0001). The presence of 5 components of the MetS increased the risk of gallstone disease by 3.4 times (P 〈 0.0001). The prevalence of GSD in women who had 5 components of NetS was 5 times higher than in those without Nets component. The more the components of Mets, the higher the prevalence of GSD (P 〈 0.0001). The presence of 5 components of the Mets increased the risk of gallstone disease by 4.0 times. CONCLUSION: GSD appears to be strongly associated with MetS, and the more the components of NetS, the higher the prevalence of GSD.
基金Innovative Research Groups of the National Natural Science Foundation of China (No.51021004)National Science Foundation of China (No. 51079096)Program for New Century Excellent Talents in University (No. NCET-08-0391)
文摘A new back-analysis method of ground stress is proposed with comprehensive consideration of influence of topography, geology and nonlinear physical mechanical properties of rock on ground stress. This method based on non-uniform rational B-spline (NURBS) technology provides the means to build a refined three-dimensional finite element model with more accurate meshing under complex terrain and geological conditions. Meanwhile, this method is a back-analysis of ground stress with combination of multivariable linear regression model and neural network (ANN) model. Firstly, the regression model is used to fit approximately boundary loads. Regarding the regressed loads as mean value, some sets of boundary loads with the same interval are constructed according to the principle of orthogonal design, to calculate the corresponding ground stress at the observation positions using finite element method. The results (boundary loads and the corresponding ground stress) are added to the samples for ANN training. And on this basis, an ANN model is established to implement higher precise back-analysis of initial ground stress. A practical application case shows that the relative error between the inversed ground stress and observed value is mostly less than 10 %, which can meet the need of engineering design and construction requirements.
基金Project supported by the National Key Research and Development Program of China(Nos.2017YFB0802303and 2016YFC0801100)the National Key Scientific Instrument and Equipment Development Projects of China(No.2013YQ49087904)+1 种基金the National Natural Science Foundation of China(No.61773270)the Miaozi Key Project in Science and Technology Innovation Program of Sichuan Province,China(No.2017RZ0016)
文摘Cascaded regression has been recently applied to reconstruct 3D faces from single 2D images directly in shape space, and has achieved state-of-the-art performance. We investigate thoroughly such cascaded regression based 3D face reconstruction approaches from four perspectives that are not well been studied: (1) the impact of the number of 2D landmarks; (2) the impact of the number of 3D vertices; (3) the way of using standalone automated landmark detection methods; (4) the convergence property. To answer these questions, a simplified cascaded regression based 3D face reconstruction method is devised. This can be integrated with standalone automated landmark detection methods and reconstruct 3D face shapes that have the same pose and expression as the input face images, rather than normalized pose and expression. An effective training method is also proposed by disturbing the automatically detected landmarks. Comprehensive evaluation experiments have been carried out to compare to other 3D face reconstruction methods. The results not only deepen the understanding of cascaded regression based 3D face reconstruction approaches, but also prove the effectiveness of the proposed method.