Researchers often explore metaheuristic algorithms for their studies.These algorithms possess unique features for solving optimization problems and are usually developed on the basis of real-world natural phenomena or...Researchers often explore metaheuristic algorithms for their studies.These algorithms possess unique features for solving optimization problems and are usually developed on the basis of real-world natural phenomena or animal and insect behavior.Numerous fields have benefited from metaheuristic algorithms for solving real-world optimization problems.As a renewable energy source,offshore wind energy is a rapidly developing subject of research,attracting considerable interest worldwide.However,designing offshore wind turbine systems can be challenging because of the large space of design parameters and different environmental conditions,and the optimization of offshore wind turbines can be extremely expensive.Nevertheless,advanced optimization methods can help to overcome these challenges.This study explores the use of metaheuristic algorithms in optimizing the design of wind turbines,including wind farm layout and wind turbine blades.Given that offshore wind energy relies more heavily on subsidies than fossil fuel-based energy sources,lowering the costs for future projects,particularly by developing new technologies and optimizing existing methods,is crucial.展开更多
This paper focuses on how to determine the instantaneous damping of the semi-active tuned mass damper (SATMD) with continuously variable damping.An off-and-towards-equilibrium (OTE) algorithm is employed to examine th...This paper focuses on how to determine the instantaneous damping of the semi-active tuned mass damper (SATMD) with continuously variable damping.An off-and-towards-equilibrium (OTE) algorithm is employed to examine the control performance of the structure/SATMD system by considering the damping as an assumptive control action.The damping modification of the SATMD is carried out according to the proposed OTE algorithm,which is formulated based on analysis of the structural movement under external excitations,and the measured responses of the structure at every time instant. As examples two numerical simulations of a five-storey and a ten-storey shear structures with a SATMD on the roof are conducted.The effectiveness on vibration reduction of MDOF systems subjected to seismic excitations is discussed.Analysis results show that the behavior of the structure with a SATMD is significantly improved and the feasibility of applying the OTE algorithm to the structural control design of SATMD is also verified.展开更多
Beam-column or beam-wall connections are an important problem in high-rise buildings. In this study, based on the analysis of an example structure, an analytical model for design of the semi-rigid connections between ...Beam-column or beam-wall connections are an important problem in high-rise buildings. In this study, based on the analysis of an example structure, an analytical model for design of the semi-rigid connections between steel beams and RC walls in high-rise hybrid buildings is proposed. Also, the mechanical characteristics of these connections subjected to low-reversed cyclic loading are investigated through comparison of experimental results from three semi-rigid connections and two rigid connections. Moreover, some latent problems for design of these connections as well as the corresponding solutions are discussed. The results from the experiments and analyses indicate that semi-rigid connections exhibit satisfactory capacity and seismic performance, and the proposed design can be used in practice.展开更多
As China opens wider to the outside world, excess liquidity has become an outstanding issue in economic operations. This paper holds that China's liquidity is relatively excessive at the present time, and such exc...As China opens wider to the outside world, excess liquidity has become an outstanding issue in economic operations. This paper holds that China's liquidity is relatively excessive at the present time, and such excess liquidity is a reflection of domestic and foreign economic contradictions on the monetary level. Excess liquidity will pose a potential hazard to macroeconomic operation, and a multi-pronged approach should be taken to curb and control its sources at home and abroad.展开更多
The outstanding properties of CVD diamond film such as electronic, optical, thermal and mechanical and the high radiation hardness have made it an ideal candidate material for radiation detectors in severe environment...The outstanding properties of CVD diamond film such as electronic, optical, thermal and mechanical and the high radiation hardness have made it an ideal candidate material for radiation detectors in severe environments. Fabrication of ＇detector grade＇ CVD diamond films and development of CVD diamond detectors have been leading edge subjects. Micro-strip gas chamber （MSGC） fabricated on CVD diamond substrate would overcome the charge-up effect and the substrate instability, which has been a hotspot in the research of gas detectors.展开更多
The basic principle of particle image velocinmetry (PIV) is described. When a PIV image is analyzed by the method of auto-correlation, there is a direction ambiguity of 180 degrees iii velocity measurement. The proble...The basic principle of particle image velocinmetry (PIV) is described. When a PIV image is analyzed by the method of auto-correlation, there is a direction ambiguity of 180 degrees iii velocity measurement. The problem can be solved by using 'Image Shifting Technique', but this makes devices much complicated and difficult to control. A new arrangement of 2-CCD (Charge Coupled Device) fully digitized PIV system, which can also solve the problem successfully, is introduced in the paper. As an example of application of the system, an experimental result of flow field around a horizontal cylinder in wave is presented.展开更多
Wood extractives in model TMP effluents and bio-treated TMP mill effluent were extracted, isolated with liquid-liquid extraction, and analyzed with GC/MS following sylilation. Acute and chronic toxicity of the effluen...Wood extractives in model TMP effluents and bio-treated TMP mill effluent were extracted, isolated with liquid-liquid extraction, and analyzed with GC/MS following sylilation. Acute and chronic toxicity of the effluent samples were tested with Ceriodaphnia dubia. Wood and bark extractives are responsible for the toxicity of the TMP effluent to aquatic life. Resin and fatty acids have a dominating contribution to acute toxicity. Removal of them from the effluent cannot deplete all toxicants, some neutral extractives such as phytosterols, are still chronically toxic to Ceriodaphnia dubia. Wood bark has a dramatic impact on acute toxicity of the TMP effluent. Only 5% of spruce bark addition can increase acute toxicity by 38.4%. However, it has a reverse trend for chronic toxicity, which indicates that some neutral wood extractives may play important role in chronic toxicity of the TMP effluent as well. Successful control of the debarking process and debark effluents is essential for achieving high-quality effluent treatment.展开更多
In this paper, the model of competing technologies diffusion was set up in order to analyze the relationship of competing technologies in diffusion process, and the stability of diffusion model with two kinds of compe...In this paper, the model of competing technologies diffusion was set up in order to analyze the relationship of competing technologies in diffusion process, and the stability of diffusion model with two kinds of competing technologies was analyzed. It is concluded that dominator can hold competing vantage by suppressing its opponent, and besides, whether competing technology can gain superiority in diffusion process depends on the success rates of technology diffusion when the two kinds of technology match each other in strength.展开更多
Adjustment of Basle Capital Agreement will influence the risk management and capital arrangement demand of the banks with different scales, operation level and environment. It will have widespread and profound effect ...Adjustment of Basle Capital Agreement will influence the risk management and capital arrangement demand of the banks with different scales, operation level and environment. It will have widespread and profound effect on the competition strength of every country＇s banks in the global market. Starting with illustration of the present cond（tion of risk management in China＇s banks, the paper analyzes the major problems existing in the risk management system of China＇s banking industry, then puts forward some clues and suggestions to improve and better the risk management system of China＇s banking industry.展开更多
For the suppliers of concerned services, theories about infrastructure pricing： SAT （Stand Alone economists such as Laffont, Tirole, etc. developed Test）, ECPR （Efficient Component Pricing Rule）. Especially, Sida...For the suppliers of concerned services, theories about infrastructure pricing： SAT （Stand Alone economists such as Laffont, Tirole, etc. developed Test）, ECPR （Efficient Component Pricing Rule）. Especially, Sidak, Spulber, put forward M-ECPR （Market Efficient Component Pricing Rule） method for bottleneck infrastructures. In this article, we bring the M-ECPR principles into the study of Chinese railways pricing of its network infrastructures. Combined with our Engineer Model and Opportunity Cost Model, we analyzed the special conditions faced by Chinese railways, and developed a model for sharing infrastructure fees among freight and passenger transportations. Engineer Model split Variable Cost （VC） and Fixed Cost （FC） into freight and passenger activities, and Opportunity Cost Model take the insufficient supply of infrastructure capacity into consideration. Of course, the subsidy from the government greatly affected the price standard for bottleneck facilities, or so-called network infrastructures.展开更多
As an innovation mode of organization, technology alliance has being increasingly paid more attention to by more and more small and medium-sized enterprises （SME）. In this paper, on the basis of analyzing the theory...As an innovation mode of organization, technology alliance has being increasingly paid more attention to by more and more small and medium-sized enterprises （SME）. In this paper, on the basis of analyzing the theory and practice meaning of the technology alliance, cooperative game method is used to analyze the forming process of the cooperative mechanism, and it points out that cooperation will make both sides get the largest benefits.展开更多
Numerical simulation of complex flow fields with multi-scale structures is one of the most important and challenging branches of computational fluid dynamics. From linear analysis and numerical experiments it has been...Numerical simulation of complex flow fields with multi-scale structures is one of the most important and challenging branches of computational fluid dynamics. From linear analysis and numerical experiments it has been discovered that the higher-order accurate method can give reliable and efficient computational results, as well as better resolution of the complex flow fields with multi-scale structures. Compact finite difference schemes, which feature higher-order accuracy and spectral-like resolution with smaller stencils and easier application of boundary conditions, has attracted more and more interest and attention.展开更多
Unified modeling language （UML） is a powerful graphical modeling language with intuitional meaning. It provides various diagrams to depict system characteristics and complex environment from different viewpoints and...Unified modeling language （UML） is a powerful graphical modeling language with intuitional meaning. It provides various diagrams to depict system characteristics and complex environment from different viewpoints and different application layers. UML-based software development and modeling environments have been widely accepted in industry, including areas in which safety is an important issue such as spaceflight, defense, automobile, etc. To ensure and improve software quality becomes a main concern in the field. As one of the key techniques for software quality, software testing can effectively detect system faults. UML based software testing based is an important research direction in software engineering. The key to software testing is the generation of test cases. This dissertation studies an approach to generating test cases from UML statecharts.展开更多
A high-energy pulse power source applied for studying solidifieation of metals and a Rogowski coil for measuring strong pulse current were developed according to the requirement of the present experiment. The variatio...A high-energy pulse power source applied for studying solidifieation of metals and a Rogowski coil for measuring strong pulse current were developed according to the requirement of the present experiment. The variation of electrical current during the discharge of pulse power source was analyzed. Furthermore, the quantitative relation between peak current, pulse width and pulse frequency etc. versus voltage, capacitance and transmission line of discharging circuit was examined.展开更多
Neural networks are being used to construct meta-models in numerical simulation of structures.In addition to network structures and training algorithms,training samples also greatly affect the accuracy of neural netwo...Neural networks are being used to construct meta-models in numerical simulation of structures.In addition to network structures and training algorithms,training samples also greatly affect the accuracy of neural network models.In this paper,some existing main sampling techniques are evaluated,including techniques based on experimental design theory, random selection,and rotating sampling.First,advantages and disadvantages of each technique are reviewed.Then,seven techniques are used to generate samples for training radial neural networks models for two benchmarks:an antenna model and an aircraft model.Results show that the uniform design,in which the number of samples and mean square error network models are considered,is the best sampling technique for neural network based meta-model building.展开更多
Monte Carlo simulations are an accurate but computationally expensive procedure for approximating the resultant non-Gaussian probability density function(PDF)after propagation of an initial Gaussian PDF through a nonl...Monte Carlo simulations are an accurate but computationally expensive procedure for approximating the resultant non-Gaussian probability density function(PDF)after propagation of an initial Gaussian PDF through a nonlinear function.Univariate splitting libraries for Gaussian Mixture Models(GMMs)exist with up to five elements in the literature.The number of splits are extended in the present work by generating three homoscedastic univariate splitting libraries with up to 39 elements.Mulitvariate GMMs are typically handled with splits along a single direction.Instead,we generate a regular multidirectional grid over the initial multivariate Gaussian distribution by recursively applying the splitting library along multiple directions.The splitting direction is arbitrary and no longer limited to directions parallel to the columns of the square-root of the covariance matrix.A second order Stirling’s interpolation of the nonlinear function evaluated at the mean of the initial Gaussian distribution is used to quantify nonlinearity along candidate splitting directions.The directions with the highest nonlinearity benefit most from splitting.The Multidirectional GMM(MGMM)has applications for uncertainty quantification with computationally intensive nonlinear functions.The variable number of splits in each direction allows for a spectrum of models in the accuracy versus compute time design space,filling the gap between expensive Monte Carlos and fast linearized models.The multidirectional method is demonstrated with four test cases,including an orbit uncertainty propagation case,to illustrate the benefit of splitting along multiple directions and of ranking the splitting directions.展开更多
Anisotropy of paper is an important parameter of paper structure. Image analysis technique was improved for accurate fiber orientation in paper surfaces. Image analysis using Fast Fourier Transform was demonstrated to...Anisotropy of paper is an important parameter of paper structure. Image analysis technique was improved for accurate fiber orientation in paper surfaces. Image analysis using Fast Fourier Transform was demonstrated to be an effective means to determine fiber orientation angle and its intensity. Binarization process of micrograph images of paper surface and precise calculation for average Fourier coefficients as an angular distribution by interpolation developed were found to improve the accuracy. This analysis method was applied to digital optical micrographs and scanning electron micrographs of paper. A laboratory handsheet showed a large deviation in the average value of fiber orientation angle, but some kinds of machine-made paper showed about 90 degrees in the orientation angle with very small deviations as expected. Korea and Japanese paper made in the traditional ways showed its own characteristic depending on its hand making processes.展开更多
文摘Researchers often explore metaheuristic algorithms for their studies.These algorithms possess unique features for solving optimization problems and are usually developed on the basis of real-world natural phenomena or animal and insect behavior.Numerous fields have benefited from metaheuristic algorithms for solving real-world optimization problems.As a renewable energy source,offshore wind energy is a rapidly developing subject of research,attracting considerable interest worldwide.However,designing offshore wind turbine systems can be challenging because of the large space of design parameters and different environmental conditions,and the optimization of offshore wind turbines can be extremely expensive.Nevertheless,advanced optimization methods can help to overcome these challenges.This study explores the use of metaheuristic algorithms in optimizing the design of wind turbines,including wind farm layout and wind turbine blades.Given that offshore wind energy relies more heavily on subsidies than fossil fuel-based energy sources,lowering the costs for future projects,particularly by developing new technologies and optimizing existing methods,is crucial.
文摘This paper focuses on how to determine the instantaneous damping of the semi-active tuned mass damper (SATMD) with continuously variable damping.An off-and-towards-equilibrium (OTE) algorithm is employed to examine the control performance of the structure/SATMD system by considering the damping as an assumptive control action.The damping modification of the SATMD is carried out according to the proposed OTE algorithm,which is formulated based on analysis of the structural movement under external excitations,and the measured responses of the structure at every time instant. As examples two numerical simulations of a five-storey and a ten-storey shear structures with a SATMD on the roof are conducted.The effectiveness on vibration reduction of MDOF systems subjected to seismic excitations is discussed.Analysis results show that the behavior of the structure with a SATMD is significantly improved and the feasibility of applying the OTE algorithm to the structural control design of SATMD is also verified.
基金National Natural Science Foundation of China Under Grant No. 50025821
文摘Beam-column or beam-wall connections are an important problem in high-rise buildings. In this study, based on the analysis of an example structure, an analytical model for design of the semi-rigid connections between steel beams and RC walls in high-rise hybrid buildings is proposed. Also, the mechanical characteristics of these connections subjected to low-reversed cyclic loading are investigated through comparison of experimental results from three semi-rigid connections and two rigid connections. Moreover, some latent problems for design of these connections as well as the corresponding solutions are discussed. The results from the experiments and analyses indicate that semi-rigid connections exhibit satisfactory capacity and seismic performance, and the proposed design can be used in practice.
文摘As China opens wider to the outside world, excess liquidity has become an outstanding issue in economic operations. This paper holds that China's liquidity is relatively excessive at the present time, and such excess liquidity is a reflection of domestic and foreign economic contradictions on the monetary level. Excess liquidity will pose a potential hazard to macroeconomic operation, and a multi-pronged approach should be taken to curb and control its sources at home and abroad.
文摘The outstanding properties of CVD diamond film such as electronic, optical, thermal and mechanical and the high radiation hardness have made it an ideal candidate material for radiation detectors in severe environments. Fabrication of ＇detector grade＇ CVD diamond films and development of CVD diamond detectors have been leading edge subjects. Micro-strip gas chamber （MSGC） fabricated on CVD diamond substrate would overcome the charge-up effect and the substrate instability, which has been a hotspot in the research of gas detectors.
基金This Project was financially supported by the National Science Foundation of China and British Council
文摘The basic principle of particle image velocinmetry (PIV) is described. When a PIV image is analyzed by the method of auto-correlation, there is a direction ambiguity of 180 degrees iii velocity measurement. The problem can be solved by using 'Image Shifting Technique', but this makes devices much complicated and difficult to control. A new arrangement of 2-CCD (Charge Coupled Device) fully digitized PIV system, which can also solve the problem successfully, is introduced in the paper. As an example of application of the system, an experimental result of flow field around a horizontal cylinder in wave is presented.
文摘Wood extractives in model TMP effluents and bio-treated TMP mill effluent were extracted, isolated with liquid-liquid extraction, and analyzed with GC/MS following sylilation. Acute and chronic toxicity of the effluent samples were tested with Ceriodaphnia dubia. Wood and bark extractives are responsible for the toxicity of the TMP effluent to aquatic life. Resin and fatty acids have a dominating contribution to acute toxicity. Removal of them from the effluent cannot deplete all toxicants, some neutral extractives such as phytosterols, are still chronically toxic to Ceriodaphnia dubia. Wood bark has a dramatic impact on acute toxicity of the TMP effluent. Only 5% of spruce bark addition can increase acute toxicity by 38.4%. However, it has a reverse trend for chronic toxicity, which indicates that some neutral wood extractives may play important role in chronic toxicity of the TMP effluent as well. Successful control of the debarking process and debark effluents is essential for achieving high-quality effluent treatment.
文摘In this paper, the model of competing technologies diffusion was set up in order to analyze the relationship of competing technologies in diffusion process, and the stability of diffusion model with two kinds of competing technologies was analyzed. It is concluded that dominator can hold competing vantage by suppressing its opponent, and besides, whether competing technology can gain superiority in diffusion process depends on the success rates of technology diffusion when the two kinds of technology match each other in strength.
文摘Adjustment of Basle Capital Agreement will influence the risk management and capital arrangement demand of the banks with different scales, operation level and environment. It will have widespread and profound effect on the competition strength of every country＇s banks in the global market. Starting with illustration of the present cond（tion of risk management in China＇s banks, the paper analyzes the major problems existing in the risk management system of China＇s banking industry, then puts forward some clues and suggestions to improve and better the risk management system of China＇s banking industry.
文摘For the suppliers of concerned services, theories about infrastructure pricing： SAT （Stand Alone economists such as Laffont, Tirole, etc. developed Test）, ECPR （Efficient Component Pricing Rule）. Especially, Sidak, Spulber, put forward M-ECPR （Market Efficient Component Pricing Rule） method for bottleneck infrastructures. In this article, we bring the M-ECPR principles into the study of Chinese railways pricing of its network infrastructures. Combined with our Engineer Model and Opportunity Cost Model, we analyzed the special conditions faced by Chinese railways, and developed a model for sharing infrastructure fees among freight and passenger transportations. Engineer Model split Variable Cost （VC） and Fixed Cost （FC） into freight and passenger activities, and Opportunity Cost Model take the insufficient supply of infrastructure capacity into consideration. Of course, the subsidy from the government greatly affected the price standard for bottleneck facilities, or so-called network infrastructures.
文摘As an innovation mode of organization, technology alliance has being increasingly paid more attention to by more and more small and medium-sized enterprises （SME）. In this paper, on the basis of analyzing the theory and practice meaning of the technology alliance, cooperative game method is used to analyze the forming process of the cooperative mechanism, and it points out that cooperation will make both sides get the largest benefits.
文摘Numerical simulation of complex flow fields with multi-scale structures is one of the most important and challenging branches of computational fluid dynamics. From linear analysis and numerical experiments it has been discovered that the higher-order accurate method can give reliable and efficient computational results, as well as better resolution of the complex flow fields with multi-scale structures. Compact finite difference schemes, which feature higher-order accuracy and spectral-like resolution with smaller stencils and easier application of boundary conditions, has attracted more and more interest and attention.
文摘Unified modeling language （UML） is a powerful graphical modeling language with intuitional meaning. It provides various diagrams to depict system characteristics and complex environment from different viewpoints and different application layers. UML-based software development and modeling environments have been widely accepted in industry, including areas in which safety is an important issue such as spaceflight, defense, automobile, etc. To ensure and improve software quality becomes a main concern in the field. As one of the key techniques for software quality, software testing can effectively detect system faults. UML based software testing based is an important research direction in software engineering. The key to software testing is the generation of test cases. This dissertation studies an approach to generating test cases from UML statecharts.
文摘A high-energy pulse power source applied for studying solidifieation of metals and a Rogowski coil for measuring strong pulse current were developed according to the requirement of the present experiment. The variation of electrical current during the discharge of pulse power source was analyzed. Furthermore, the quantitative relation between peak current, pulse width and pulse frequency etc. versus voltage, capacitance and transmission line of discharging circuit was examined.
基金Specialized Research Fund for the Doctoral Program of Higher Education,China (No.20010227012)
文摘Neural networks are being used to construct meta-models in numerical simulation of structures.In addition to network structures and training algorithms,training samples also greatly affect the accuracy of neural network models.In this paper,some existing main sampling techniques are evaluated,including techniques based on experimental design theory, random selection,and rotating sampling.First,advantages and disadvantages of each technique are reviewed.Then,seven techniques are used to generate samples for training radial neural networks models for two benchmarks:an antenna model and an aircraft model.Results show that the uniform design,in which the number of samples and mean square error network models are considered,is the best sampling technique for neural network based meta-model building.
文摘Monte Carlo simulations are an accurate but computationally expensive procedure for approximating the resultant non-Gaussian probability density function(PDF)after propagation of an initial Gaussian PDF through a nonlinear function.Univariate splitting libraries for Gaussian Mixture Models(GMMs)exist with up to five elements in the literature.The number of splits are extended in the present work by generating three homoscedastic univariate splitting libraries with up to 39 elements.Mulitvariate GMMs are typically handled with splits along a single direction.Instead,we generate a regular multidirectional grid over the initial multivariate Gaussian distribution by recursively applying the splitting library along multiple directions.The splitting direction is arbitrary and no longer limited to directions parallel to the columns of the square-root of the covariance matrix.A second order Stirling’s interpolation of the nonlinear function evaluated at the mean of the initial Gaussian distribution is used to quantify nonlinearity along candidate splitting directions.The directions with the highest nonlinearity benefit most from splitting.The Multidirectional GMM(MGMM)has applications for uncertainty quantification with computationally intensive nonlinear functions.The variable number of splits in each direction allows for a spectrum of models in the accuracy versus compute time design space,filling the gap between expensive Monte Carlos and fast linearized models.The multidirectional method is demonstrated with four test cases,including an orbit uncertainty propagation case,to illustrate the benefit of splitting along multiple directions and of ranking the splitting directions.
文摘Anisotropy of paper is an important parameter of paper structure. Image analysis technique was improved for accurate fiber orientation in paper surfaces. Image analysis using Fast Fourier Transform was demonstrated to be an effective means to determine fiber orientation angle and its intensity. Binarization process of micrograph images of paper surface and precise calculation for average Fourier coefficients as an angular distribution by interpolation developed were found to improve the accuracy. This analysis method was applied to digital optical micrographs and scanning electron micrographs of paper. A laboratory handsheet showed a large deviation in the average value of fiber orientation angle, but some kinds of machine-made paper showed about 90 degrees in the orientation angle with very small deviations as expected. Korea and Japanese paper made in the traditional ways showed its own characteristic depending on its hand making processes.
