In recent years, with the rapid development of urbanization in China, land acquisition work is particularly important. The division of expropriated area is the primary factor to be considered when evaluating the compr...In recent years, with the rapid development of urbanization in China, land acquisition work is particularly important. The division of expropriated area is the primary factor to be considered when evaluating the comprehensive land price of expropriated area. Reasonable division can help to improve the scientific and applicability of the comprehensive land price of the region. How to maximize the protection of farmers’ rights and interests by the division of land requisition is an urgent problem to be solved. Taking Gongcheng Yao Autonomous County as an example, this study adopted the multi-factor comprehensive evaluation method to evaluate the division of land requisition in this area, and carried out the corresponding spatial analysis and data processing based on GIS technology. Gongcheng Yao Autonomous County was divided into levy areas, and the Delphi method was used to screen the impact factors and determine the weight of the levy areas. Reasonable division of land requisition area can provide references for land requisition area, make it more scientific and reasonable, and protect the rights and interests of farmers.展开更多
BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study s...BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study set out to establish the clinical risk factors resulting in IPGF after OLT. METHODS: Eighty cases of OLT were analyzed. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) above 1500 IU/L within 72 hours after OLT, while those in the non-IPGF group had values below 1500 IU/L. Recipient-associated factors before OLT analyzed were age, sex, primary liver disease and Child-Pugh classification; factors analyzed within the peri-operative period were non-heart beating time (NHBT), cold ischemia time (CIT), rewarming ischemic time (RWIT), liver biopsy at the end of cold ischemia; and factors analyzed within 72 hours after OLT were ALT and/or AST values. A logistic regression model was applied to filter the possible factors resulting in IPGF. RESULTS: Donor NHBT, CIT and RWIT were significantly longer in the IPGF group than in the non-IPGF group; in the logistic regression model, NHBT was the risk factor leading to IPGF (P<0.05), while CIT and RWIT were possible risk factors. In one case in the IPGF group, PGNF appeared with moderate hepatic steatosis. CONCLUSIONS: Longer NHBT is an important risk factor leading to IPGF, while serious steatosis in the donor liver, CIT and RWIT are potential risk factors.展开更多
Deepwater oil and gas projects embody high risks from geology and engineering aspects, which exert substantial influence on project valuation. But the uncertainties may be converted to additional value to the projects...Deepwater oil and gas projects embody high risks from geology and engineering aspects, which exert substantial influence on project valuation. But the uncertainties may be converted to additional value to the projects in the case of flexible management. Given the flexibility of project management, this paper extends the classical real options model to a multi-factor model which contains oil price, geology, and engineering uncertainties. It then gives an application example of the new model to evaluate deepwater oil and gas projects with a numerical analytical method. Compared with other methods and models, this multi-factor real options model contains more project information. It reflects the potential value deriving not only from oil price variation but also from geology and engineering uncertainties, which provides more accurate and reliable valuation information for decision makers.展开更多
In order to accurately simulate the diffusion of chloride ion in the existing concrete bridge and acquire the precise chloride ion concentration at given time, a cellular automata (CA)-based model is proposed. The pro...In order to accurately simulate the diffusion of chloride ion in the existing concrete bridge and acquire the precise chloride ion concentration at given time, a cellular automata (CA)-based model is proposed. The process of chloride ion diffusion is analyzed by the CA-based method and a nonlinear solution of the Fick's second law is obtained. Considering the impact of various factors such as stress states, temporal and spatial variability of diffusion parameters and water-cement ratio on the process of chloride ion diffusion, the model of chloride ion diffusion under multi-factor coupling actions is presented. A chloride ion penetrating experiment reported in the literature is used to prove the effectiveness and reasonability of the present method, and a T-type beam is taken as an illustrative example to analyze the process of chloride ion diffusion in practical application. The results indicate that CA-based method can simulate the diffusion of chloride ion in the concrete structures with acceptable precision.展开更多
Fuzzy sets theory cannot describe the neutrality degree of data, which has largely limited the objectivity of fuzzy time series in uncertain data forecasting. With this regard, a multi-factor highorder intuitionistic ...Fuzzy sets theory cannot describe the neutrality degree of data, which has largely limited the objectivity of fuzzy time series in uncertain data forecasting. With this regard, a multi-factor highorder intuitionistic fuzzy time series forecasting model is built. In the new model, a fuzzy clustering algorithm is used to get unequal intervals, and a more objective technique for ascertaining membership and non-membership functions of the intuitionistic fuzzy set is proposed. On these bases, forecast rules based on multidimensional intuitionistic fuzzy modus ponens inference are established.Finally, contrast experiments on the daily mean temperature of Beijing are carried out, which show that the novel model has a clear advantage of improving the forecast accuracy.展开更多
An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was...An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was reconstructed. Sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was proposed to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping angle, water content, hydrostatic pressure, seismic force as well as train load were analyzed. The range and correlation of the above-mentioned factors were discussed and coupled wave equations were established to reflect the relationships between unit weight, cohesion, internal frictional angle, and water content, as well as between internal frictional angle and cohesion. The sensitivity analysis of slope stability was carried out and susceptive factors were determined when the factors were taken as independent and dependent variables respectively. The results show that sloping angle, water content and earthquake are the principal susceptive factors influencing slope stability. The impact of hydrostatic pressure on slope stability is similar to the seismic force in quantity. Train load plays a small role in slope stability and its influencing only reaches the roadbed and its neighboring slope segment. If the factors are taken as independent variables, the influencing extent of water content and cohesion on slope stability can be weakened and train load can be magnified.展开更多
Most network service providers like MTN Nigeria, currently use two-factor authentication for their 4G wireless networks. This exposes the network subscribers to identify theft and users data to security threats like s...Most network service providers like MTN Nigeria, currently use two-factor authentication for their 4G wireless networks. This exposes the network subscribers to identify theft and users data to security threats like snooping, sniffing, spoofing and phishing. There is need to curb these problems with the use of an enhanced multi-factor authentication approach. The objective of this work is to create a multi-factor authentication software for a 4G wireless network. Multi-factor authentication involves user’s knowledge factor, user’s possession factor and user’s inherence factor;that is who the user is to be presented before system access can be granted. The research methodologies used for this work include Structured System Analysis and Design Methodology, SSADM and Prototyping. The result of this work will be a Multi-factor authentications software. This software was designed with programming languages like ASP. NET, C# and Microsoft SQL Server for the database.展开更多
By using a farm's data in Yantai City and the theory of Cost-Volume-Profit analysis and the financial management methods,this paper construct a multi-factor analysis model for improving profit management using Exc...By using a farm's data in Yantai City and the theory of Cost-Volume-Profit analysis and the financial management methods,this paper construct a multi-factor analysis model for improving profit management using Excel 2007 in Shellfish farming projects and describes the procedures to construct a multi-factor analysis model.The model can quickly calculate the profit,improve the level of profit management,find out the breakeven point and enhance the decision-making efficiency of businesses etc.It is also a thought of the application to offer suggestions for government decisions and economic decisions for corporations as a simple analysis tool.While effort has been exerted to construct a four-variable model,some equally important variables may not be discussed sufficiently due to limitation of the paper's space and the authors'knowledge.All variables can be listed in EXCEL 2007 and can be associated in a logical way to manage the profit of shellfish farming projects more efficiently and more practically.展开更多
In this study, artificial leaf resistance was used to simulate leaf wetness. Specific to the solar greenhouse environment in Tianjin, microclimate monitoring equipment was installed for the collection of temperature g...In this study, artificial leaf resistance was used to simulate leaf wetness. Specific to the solar greenhouse environment in Tianjin, microclimate monitoring equipment was installed for the collection of temperature group and humidity group data, as well as solar radiation and leaf wetness in the greenhouse. In order to reduce the complexity of multivariate factor prediction and ensure the richness of selected data types, correlation analysis was made to the 2 groups of data, screening 5 000 groups of data, including the humidity group data RH, RH_(20), RH_(40), temperature group data T, T_(20), T_(40), and solar radiation W. The data were then analyzed by principal component analysis, screening out 4 groups of principal components to show the leaf wetness index.展开更多
Reservoir safety, testing-string safety, and flow control are key factors that should be considered in deep-water unconsolidated sandstone gas well testing work system. Combined with the feature of testing reservoir, ...Reservoir safety, testing-string safety, and flow control are key factors that should be considered in deep-water unconsolidated sandstone gas well testing work system. Combined with the feature of testing reservoir, pipe string type and sea area, the required minimum testing flow rate during cleaning up process, as well as minimum test flow rate without hydrate generation, pipe string erosion critical production, the maximum testing flow rate without destroying sand formation and the minimum output of meeting the demand of development was analyzed;based on the above critical test flow rates, testing working system is designed. Field application showed that the designed work system effectively provided good guidance for field test operations;no sand production or hydrate generation happened during the test process;the test parameter evaluated the reservoir accurately;the safe and efficient test operation was achieved.展开更多
This letter studies and analyzes the working features of main circuit of tri-level boost Power Factor Correct(PFC) converter and the advantages of tri-level switch converter in aspects of bearing high-voltage of power...This letter studies and analyzes the working features of main circuit of tri-level boost Power Factor Correct(PFC) converter and the advantages of tri-level switch converter in aspects of bearing high-voltage of power components,overall system loss and magnetic component selection based upon the single-level boost PFC switch converter.Besides,relying on the application of mi-croprocessor in power converter technology and DSP(Digital Signal Processing) chip's strong cal-culating capacity,the letter presents the adoption of modified scheme of tri-level boost PFC converter under the control of predictive control algorithm.Moreover,the operating principle and control method are specified,the results of circuit test and analysis are provided and the advantages of pre-dictive control technology-based multi-level boost PFC converter is verified.展开更多
Generation of single-sideband (SSB) multi-carrier source based on a recirculating frequency shifter (RFS) is anal-ysed theoretically and realized experimentally.The effects of affecting factors originating from the de...Generation of single-sideband (SSB) multi-carrier source based on a recirculating frequency shifter (RFS) is anal-ysed theoretically and realized experimentally.The effects of affecting factors originating from the deviation from the right operation bias voltage and unbalanced amplitude,and the phase of the radio frequency (RF) drive signals on the performance of the multi-tone source are discussed in detail.Based on the theoretical analysis,high-quality 50-tone out-put is successfully realized.Experiments under some implementation imperfections are also carried out.The imperfect and low-quality output results are in good agreement with theoretical analysis.展开更多
文摘In recent years, with the rapid development of urbanization in China, land acquisition work is particularly important. The division of expropriated area is the primary factor to be considered when evaluating the comprehensive land price of expropriated area. Reasonable division can help to improve the scientific and applicability of the comprehensive land price of the region. How to maximize the protection of farmers’ rights and interests by the division of land requisition is an urgent problem to be solved. Taking Gongcheng Yao Autonomous County as an example, this study adopted the multi-factor comprehensive evaluation method to evaluate the division of land requisition in this area, and carried out the corresponding spatial analysis and data processing based on GIS technology. Gongcheng Yao Autonomous County was divided into levy areas, and the Delphi method was used to screen the impact factors and determine the weight of the levy areas. Reasonable division of land requisition area can provide references for land requisition area, make it more scientific and reasonable, and protect the rights and interests of farmers.
基金This study was supported by a grant from the Shanghai Science and Technology Commission Foundation, China(No.O14119002).
文摘BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study set out to establish the clinical risk factors resulting in IPGF after OLT. METHODS: Eighty cases of OLT were analyzed. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) above 1500 IU/L within 72 hours after OLT, while those in the non-IPGF group had values below 1500 IU/L. Recipient-associated factors before OLT analyzed were age, sex, primary liver disease and Child-Pugh classification; factors analyzed within the peri-operative period were non-heart beating time (NHBT), cold ischemia time (CIT), rewarming ischemic time (RWIT), liver biopsy at the end of cold ischemia; and factors analyzed within 72 hours after OLT were ALT and/or AST values. A logistic regression model was applied to filter the possible factors resulting in IPGF. RESULTS: Donor NHBT, CIT and RWIT were significantly longer in the IPGF group than in the non-IPGF group; in the logistic regression model, NHBT was the risk factor leading to IPGF (P<0.05), while CIT and RWIT were possible risk factors. In one case in the IPGF group, PGNF appeared with moderate hepatic steatosis. CONCLUSIONS: Longer NHBT is an important risk factor leading to IPGF, while serious steatosis in the donor liver, CIT and RWIT are potential risk factors.
基金supported from the National Science and Technology Major Project under Grant No.2011ZX05030
文摘Deepwater oil and gas projects embody high risks from geology and engineering aspects, which exert substantial influence on project valuation. But the uncertainties may be converted to additional value to the projects in the case of flexible management. Given the flexibility of project management, this paper extends the classical real options model to a multi-factor model which contains oil price, geology, and engineering uncertainties. It then gives an application example of the new model to evaluate deepwater oil and gas projects with a numerical analytical method. Compared with other methods and models, this multi-factor real options model contains more project information. It reflects the potential value deriving not only from oil price variation but also from geology and engineering uncertainties, which provides more accurate and reliable valuation information for decision makers.
基金the National Natural Science Foundation of China (No.51178305)Key Projects in the Science & Technology Pillar Program of Tianjin (No.11ZCKFSF00300)
文摘In order to accurately simulate the diffusion of chloride ion in the existing concrete bridge and acquire the precise chloride ion concentration at given time, a cellular automata (CA)-based model is proposed. The process of chloride ion diffusion is analyzed by the CA-based method and a nonlinear solution of the Fick's second law is obtained. Considering the impact of various factors such as stress states, temporal and spatial variability of diffusion parameters and water-cement ratio on the process of chloride ion diffusion, the model of chloride ion diffusion under multi-factor coupling actions is presented. A chloride ion penetrating experiment reported in the literature is used to prove the effectiveness and reasonability of the present method, and a T-type beam is taken as an illustrative example to analyze the process of chloride ion diffusion in practical application. The results indicate that CA-based method can simulate the diffusion of chloride ion in the concrete structures with acceptable precision.
基金supported by the National Natural Science Foundation of China(61309022)
文摘Fuzzy sets theory cannot describe the neutrality degree of data, which has largely limited the objectivity of fuzzy time series in uncertain data forecasting. With this regard, a multi-factor highorder intuitionistic fuzzy time series forecasting model is built. In the new model, a fuzzy clustering algorithm is used to get unequal intervals, and a more objective technique for ascertaining membership and non-membership functions of the intuitionistic fuzzy set is proposed. On these bases, forecast rules based on multidimensional intuitionistic fuzzy modus ponens inference are established.Finally, contrast experiments on the daily mean temperature of Beijing are carried out, which show that the novel model has a clear advantage of improving the forecast accuracy.
基金This work was financially supported by the National Natural Science Foundation of China (No. 50490271).
文摘An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was reconstructed. Sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was proposed to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping angle, water content, hydrostatic pressure, seismic force as well as train load were analyzed. The range and correlation of the above-mentioned factors were discussed and coupled wave equations were established to reflect the relationships between unit weight, cohesion, internal frictional angle, and water content, as well as between internal frictional angle and cohesion. The sensitivity analysis of slope stability was carried out and susceptive factors were determined when the factors were taken as independent and dependent variables respectively. The results show that sloping angle, water content and earthquake are the principal susceptive factors influencing slope stability. The impact of hydrostatic pressure on slope stability is similar to the seismic force in quantity. Train load plays a small role in slope stability and its influencing only reaches the roadbed and its neighboring slope segment. If the factors are taken as independent variables, the influencing extent of water content and cohesion on slope stability can be weakened and train load can be magnified.
文摘Most network service providers like MTN Nigeria, currently use two-factor authentication for their 4G wireless networks. This exposes the network subscribers to identify theft and users data to security threats like snooping, sniffing, spoofing and phishing. There is need to curb these problems with the use of an enhanced multi-factor authentication approach. The objective of this work is to create a multi-factor authentication software for a 4G wireless network. Multi-factor authentication involves user’s knowledge factor, user’s possession factor and user’s inherence factor;that is who the user is to be presented before system access can be granted. The research methodologies used for this work include Structured System Analysis and Design Methodology, SSADM and Prototyping. The result of this work will be a Multi-factor authentications software. This software was designed with programming languages like ASP. NET, C# and Microsoft SQL Server for the database.
文摘By using a farm's data in Yantai City and the theory of Cost-Volume-Profit analysis and the financial management methods,this paper construct a multi-factor analysis model for improving profit management using Excel 2007 in Shellfish farming projects and describes the procedures to construct a multi-factor analysis model.The model can quickly calculate the profit,improve the level of profit management,find out the breakeven point and enhance the decision-making efficiency of businesses etc.It is also a thought of the application to offer suggestions for government decisions and economic decisions for corporations as a simple analysis tool.While effort has been exerted to construct a four-variable model,some equally important variables may not be discussed sufficiently due to limitation of the paper's space and the authors'knowledge.All variables can be listed in EXCEL 2007 and can be associated in a logical way to manage the profit of shellfish farming projects more efficiently and more practically.
基金Supported by the Innovation Research and Experiments for Young Scientists(2018009)the Project for the Transformation and Promotion of Agricultural Science and Technology Achievements of Tianjin(201801040)+1 种基金the Modern Agriculture Industry System for Vegetables of Tianjin(ITTVRS2017018)the Science and Technology Planning Project of Tianjin(17YFZCNC00280)
文摘In this study, artificial leaf resistance was used to simulate leaf wetness. Specific to the solar greenhouse environment in Tianjin, microclimate monitoring equipment was installed for the collection of temperature group and humidity group data, as well as solar radiation and leaf wetness in the greenhouse. In order to reduce the complexity of multivariate factor prediction and ensure the richness of selected data types, correlation analysis was made to the 2 groups of data, screening 5 000 groups of data, including the humidity group data RH, RH_(20), RH_(40), temperature group data T, T_(20), T_(40), and solar radiation W. The data were then analyzed by principal component analysis, screening out 4 groups of principal components to show the leaf wetness index.
文摘Reservoir safety, testing-string safety, and flow control are key factors that should be considered in deep-water unconsolidated sandstone gas well testing work system. Combined with the feature of testing reservoir, pipe string type and sea area, the required minimum testing flow rate during cleaning up process, as well as minimum test flow rate without hydrate generation, pipe string erosion critical production, the maximum testing flow rate without destroying sand formation and the minimum output of meeting the demand of development was analyzed;based on the above critical test flow rates, testing working system is designed. Field application showed that the designed work system effectively provided good guidance for field test operations;no sand production or hydrate generation happened during the test process;the test parameter evaluated the reservoir accurately;the safe and efficient test operation was achieved.
文摘This letter studies and analyzes the working features of main circuit of tri-level boost Power Factor Correct(PFC) converter and the advantages of tri-level switch converter in aspects of bearing high-voltage of power components,overall system loss and magnetic component selection based upon the single-level boost PFC switch converter.Besides,relying on the application of mi-croprocessor in power converter technology and DSP(Digital Signal Processing) chip's strong cal-culating capacity,the letter presents the adoption of modified scheme of tri-level boost PFC converter under the control of predictive control algorithm.Moreover,the operating principle and control method are specified,the results of circuit test and analysis are provided and the advantages of pre-dictive control technology-based multi-level boost PFC converter is verified.
基金Project supported by the National Natural Science Foundation of China (Grant No.60977049)the Chinese Universities Scientific Fund (Grant No.BUPT 2009RC0413)
文摘Generation of single-sideband (SSB) multi-carrier source based on a recirculating frequency shifter (RFS) is anal-ysed theoretically and realized experimentally.The effects of affecting factors originating from the deviation from the right operation bias voltage and unbalanced amplitude,and the phase of the radio frequency (RF) drive signals on the performance of the multi-tone source are discussed in detail.Based on the theoretical analysis,high-quality 50-tone out-put is successfully realized.Experiments under some implementation imperfections are also carried out.The imperfect and low-quality output results are in good agreement with theoretical analysis.
