The problems including excessive flow of attemperating water for boiler, failure of butterfly valve at the outlet of circulating water pump, burnt-out of thyristor for excitation regulator, load variation rate of CCS ...The problems including excessive flow of attemperating water for boiler, failure of butterfly valve at the outlet of circulating water pump, burnt-out of thyristor for excitation regulator, load variation rate of CCS not complying with the contract target, etc. occurred during start-up and debugging of two 600 MW generating units in Yangzhou No.2 Thermal Power Plant. Through analysis on these problems. the remedial measures were put forward, to which can be referred for similar units.展开更多
Terrain texture analysis is an important method of digital terrain analysis in quantitative geomorphological research and in the exploration of the spatial heterogeneity and autocorrelation of terrain features. Howeve...Terrain texture analysis is an important method of digital terrain analysis in quantitative geomorphological research and in the exploration of the spatial heterogeneity and autocorrelation of terrain features. However, a major issue often neglected in previous studies is the calculation unit of the terrain texture, that is, the stability analysis unit. As the test size increases, the derived terrain textures become increasingly similar so that their differences can be ignored. The test size of terrain texture is defined as the stability analysis unit. This study randomly selected 48 areas within the Loess Plateau in northern Shaanxi in China as the study sites and used the gray level co-occurrence matrix to calculate the terrain texture. The stability analysis unit of the terrain texture was then extracted, and its spatial distribution pattern in the Loess Plateau was studiedusing spatial interpolation method. Four terrain texture metrics, i.e., homogeneity, energy, correlation, and contrast, were extracted on the basis of the stability analysis unit, and the spatial variation patterns of these parameters were studied. Results showed that the spatial distribution pattern and the terrain texture metrics reflected a trend of high–low–high from north to south, which correlated with the spatial distribution of the landforms at the Loess Plateau. In addition, the terrain texture measures was significantly correlated with the terrain factors of gully density and slope, and this relationship showed that terrain texture measures based on the stability analysis unit could reflect the basic characteristics of terrain morphology. The stability analysis unit provided a reasonable analytical scale for terrain texture analysis and could be used as a measure of the regional topography to accurately describe basic terrain characteristics.展开更多
Concession contracts in highways often include some kind of clauses (for example, a minimum traffic guarantee) that allow for better management of the business risks. The value of these clauses may be important and ...Concession contracts in highways often include some kind of clauses (for example, a minimum traffic guarantee) that allow for better management of the business risks. The value of these clauses may be important and should be added to the total value of the concession. However, in these cases, traditional valuation techniques, like the NPV (net present value) of the project, are insufficient. An alternative methodology for the valuation of highway concession is one based on the real options approach. This methodology is generally built on the assumption of the evolution of traffic volume as a GBM (geometric Brownian motion), which is the hypothesis analyzed in this paper. First, a description of the methodology used for the analysis of the existence of unit roots (i.e., the hypothesis of non-stationarity) is provided. The Dickey-Fuller approach has been used, which is the most common test for this kind of analysis. Then this methodology is applied to perform a statistical analysis of traffic series in Spanish toll highways. For this purpose, data on the AADT (annual average daily traffic) on a set of highways have been used. The period of analysis is around thirty years in most cases. The main outcome of the research is that the hypothesis that traffic volume follows a GBM process in Spanish toll highways cannot be rejected. This result is robust, and therefore it can be used as a starting point for the application of the real options theory to assess toll highway concessions.展开更多
Summary This paper analyses the turbine bypass system design and operation mode for domestically made 300 MW unit with technology imported, and put forward some suggestions about whether bypass system is needed. 1.0 I...Summary This paper analyses the turbine bypass system design and operation mode for domestically made 300 MW unit with technology imported, and put forward some suggestions about whether bypass system is needed. 1.0 Introduction The domestically made WH Co, patent 300 MW unit is produced according to the technology of American Westinghouse (WH) Corporation. The original展开更多
The control rod drive mechanism(CRDM)is an essential part of the control and safety protection system of pressurized water reactors.Current CRDM simulations are mostly performed collectively using a single method,igno...The control rod drive mechanism(CRDM)is an essential part of the control and safety protection system of pressurized water reactors.Current CRDM simulations are mostly performed collectively using a single method,ignoring the influence of multiple motion units and the differences in various features among them,which strongly affect the efficiency and accuracy of the simulations.In this study,we constructed a flow field fusion simulation method based on model features by combining key motion unit analysis and various simulation methods and then applied the method to the CRDM simulation process.CRDM performs motion unit decomposition through the structural hierarchy of function-movement-action method,and the key meta-actions are identified as the nodes in the flow field simulation.We established a fused feature-based multimethod simulation process and processed the simulation methods and data according to the features of the fluid domain space and the structural complexity to obtain the fusion simulation results.Compared to traditional simulation methods and real measurements,the simulation method provides advantages in terms of simulation efficiency and accuracy.展开更多
In remote sensing community, IHS (intensity, hue, and saturation) transform is one of the most commonly used fusion algorithm. A study on IHS fusion indicates that the color distortion cannot be avoided. Meanwhile, wa...In remote sensing community, IHS (intensity, hue, and saturation) transform is one of the most commonly used fusion algorithm. A study on IHS fusion indicates that the color distortion cannot be avoided. Meanwhile, wavelet decomposition has a property of frequency division in transform domain. And the statistical property of wavelet coefficient reflects those significant features. So, a united optimal fusion method, which using the statistical property of wavelet decomposition and IHS transform on pixel and展开更多
The population analysis unit(PAU)is the basic unit employed in studies of urban populations.The commonly used PAUs are mostly administrative divisions,regular geographic grids.However,these units are different from ur...The population analysis unit(PAU)is the basic unit employed in studies of urban populations.The commonly used PAUs are mostly administrative divisions,regular geographic grids.However,these units are different from urban forms,and cannot be used to consider the characteristics of population distributions and flow changes.In this study,we proposed a method for constructing a fine population analysis zone(FPAZ)based on the population aggregation pattern and urban form elements.First,considering the spatial structure of a city and the fine-grained demands of population analysis,the basic analysis unit was divided according to the functional heterogeneity of the population activity region at the micro-scale by combining urban form elements.Next,a population aggregation preference model was established by considering the spatial distribution characteristics of the local aggregation of the urban population flow and long-term stability characteristics depending on the dynamic changes in entrances and exits.Finally,we divided the FPAZ combined with the microstructural elements.Experimental results showed that compared with other types of PAUs,the FPAZ was more consistent with the urban morphology and was an appropriate and general spatial unit for expressing the accurate characteristics of population distributions and changes at the micro-scale.展开更多
The negative secondary ion mass spectrometry,in combination with the stereoselective derivatizations with substituted boronic acid RB(OH)_2,was used in the analysis of fourteen oligosac- charides.The mass spectra of t...The negative secondary ion mass spectrometry,in combination with the stereoselective derivatizations with substituted boronic acid RB(OH)_2,was used in the analysis of fourteen oligosac- charides.The mass spectra of the derivatives provide information on their linkage Positions and iso- merism of the individual monoscaccharide units.The results indicated that among the derivatives of the oligosaccharides analyzed,those with 1—4 and 1—6 linkages all presented the ion peaks at m/z 287,sometimes one more peak at m/z 449.Furthermore,a relationship was found between the linkage positions and the intensity orders of the derivative ions.Finally,the derivatives of the disaccharides with a galactose presented an intense ion peak at m/z 347,and those of oligosaccharides with 1—6 linkage to a galactose at terminal presented the ion at m/z 317.In the case of oligosaccharides with a fructose residue,characteristic ion of m/z 155 was produced.The conditions of stereoselective derivatizations and mass spectrometry were studied,in order to obtain a better reproducibility of the mass spectra.展开更多
This paper describes the analysis and design of an assistive device for elderly people under development at the EgyptJapan University of Science and Technology(E-JUST) named E-JUST assistive device(EJAD).Several e...This paper describes the analysis and design of an assistive device for elderly people under development at the EgyptJapan University of Science and Technology(E-JUST) named E-JUST assistive device(EJAD).Several experiments were carried out using a motion capture system(VICON) and inertial sensors to identify the human posture during the sit-to-stand motion.The EJAD uses only two inertial measurement units(IMUs) fused through an adaptive neuro-fuzzy inference systems(ANFIS) algorithm to imitate the real motion of the caregiver.The EJAD consists of two main parts,a robot arm and an active walker.The robot arm is a 2-degree-of-freedom(2-DOF) planar manipulator.In addition,a back support with a passive joint is used to support the patient s back.The IMUs on the leg and trunk of the patient are used to compensate for and adapt to the EJAD system motion depending on the obtained patient posture.The ANFIS algorithm is used to train the fuzzy system that converts the IMUs signals to the right posture of the patient.A control scheme is proposed to control the system motion based on practical measurements taken from the experiments.A computer simulation showed a relatively good performance of the EJAD in assisting the patient.展开更多
文摘The problems including excessive flow of attemperating water for boiler, failure of butterfly valve at the outlet of circulating water pump, burnt-out of thyristor for excitation regulator, load variation rate of CCS not complying with the contract target, etc. occurred during start-up and debugging of two 600 MW generating units in Yangzhou No.2 Thermal Power Plant. Through analysis on these problems. the remedial measures were put forward, to which can be referred for similar units.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41471316, 41571383, 41671389)the Priority Academic Program Development of Jiangsu Higher Education Institutions-PAPD (Grant No. 164320H101)the Key Project of Natural Science Research of Anhui Provincial Department of Education (Grant No. KJ2015A171)
文摘Terrain texture analysis is an important method of digital terrain analysis in quantitative geomorphological research and in the exploration of the spatial heterogeneity and autocorrelation of terrain features. However, a major issue often neglected in previous studies is the calculation unit of the terrain texture, that is, the stability analysis unit. As the test size increases, the derived terrain textures become increasingly similar so that their differences can be ignored. The test size of terrain texture is defined as the stability analysis unit. This study randomly selected 48 areas within the Loess Plateau in northern Shaanxi in China as the study sites and used the gray level co-occurrence matrix to calculate the terrain texture. The stability analysis unit of the terrain texture was then extracted, and its spatial distribution pattern in the Loess Plateau was studiedusing spatial interpolation method. Four terrain texture metrics, i.e., homogeneity, energy, correlation, and contrast, were extracted on the basis of the stability analysis unit, and the spatial variation patterns of these parameters were studied. Results showed that the spatial distribution pattern and the terrain texture metrics reflected a trend of high–low–high from north to south, which correlated with the spatial distribution of the landforms at the Loess Plateau. In addition, the terrain texture measures was significantly correlated with the terrain factors of gully density and slope, and this relationship showed that terrain texture measures based on the stability analysis unit could reflect the basic characteristics of terrain morphology. The stability analysis unit provided a reasonable analytical scale for terrain texture analysis and could be used as a measure of the regional topography to accurately describe basic terrain characteristics.
文摘Concession contracts in highways often include some kind of clauses (for example, a minimum traffic guarantee) that allow for better management of the business risks. The value of these clauses may be important and should be added to the total value of the concession. However, in these cases, traditional valuation techniques, like the NPV (net present value) of the project, are insufficient. An alternative methodology for the valuation of highway concession is one based on the real options approach. This methodology is generally built on the assumption of the evolution of traffic volume as a GBM (geometric Brownian motion), which is the hypothesis analyzed in this paper. First, a description of the methodology used for the analysis of the existence of unit roots (i.e., the hypothesis of non-stationarity) is provided. The Dickey-Fuller approach has been used, which is the most common test for this kind of analysis. Then this methodology is applied to perform a statistical analysis of traffic series in Spanish toll highways. For this purpose, data on the AADT (annual average daily traffic) on a set of highways have been used. The period of analysis is around thirty years in most cases. The main outcome of the research is that the hypothesis that traffic volume follows a GBM process in Spanish toll highways cannot be rejected. This result is robust, and therefore it can be used as a starting point for the application of the real options theory to assess toll highway concessions.
文摘Summary This paper analyses the turbine bypass system design and operation mode for domestically made 300 MW unit with technology imported, and put forward some suggestions about whether bypass system is needed. 1.0 Introduction The domestically made WH Co, patent 300 MW unit is produced according to the technology of American Westinghouse (WH) Corporation. The original
基金supported by the National Natural Science Foundation of China (No. 52075350)the Special City School Strategic Cooperation Project of Sichuan University and Zigong (No.2021CDZG-3)
文摘The control rod drive mechanism(CRDM)is an essential part of the control and safety protection system of pressurized water reactors.Current CRDM simulations are mostly performed collectively using a single method,ignoring the influence of multiple motion units and the differences in various features among them,which strongly affect the efficiency and accuracy of the simulations.In this study,we constructed a flow field fusion simulation method based on model features by combining key motion unit analysis and various simulation methods and then applied the method to the CRDM simulation process.CRDM performs motion unit decomposition through the structural hierarchy of function-movement-action method,and the key meta-actions are identified as the nodes in the flow field simulation.We established a fused feature-based multimethod simulation process and processed the simulation methods and data according to the features of the fluid domain space and the structural complexity to obtain the fusion simulation results.Compared to traditional simulation methods and real measurements,the simulation method provides advantages in terms of simulation efficiency and accuracy.
基金This work was jointly supported by the National Natural Science Foundation of China (No. 60375008), China National '863' Project (No. 2001AA135091), Shanghai Key Scientific Project (No. 02DZ15001), Aviation Science Foundation (No. 02D57003), and China Ph
文摘In remote sensing community, IHS (intensity, hue, and saturation) transform is one of the most commonly used fusion algorithm. A study on IHS fusion indicates that the color distortion cannot be avoided. Meanwhile, wavelet decomposition has a property of frequency division in transform domain. And the statistical property of wavelet coefficient reflects those significant features. So, a united optimal fusion method, which using the statistical property of wavelet decomposition and IHS transform on pixel and
基金supported by the National Natural Science Foundation of China(U20A2091,41771426).
文摘The population analysis unit(PAU)is the basic unit employed in studies of urban populations.The commonly used PAUs are mostly administrative divisions,regular geographic grids.However,these units are different from urban forms,and cannot be used to consider the characteristics of population distributions and flow changes.In this study,we proposed a method for constructing a fine population analysis zone(FPAZ)based on the population aggregation pattern and urban form elements.First,considering the spatial structure of a city and the fine-grained demands of population analysis,the basic analysis unit was divided according to the functional heterogeneity of the population activity region at the micro-scale by combining urban form elements.Next,a population aggregation preference model was established by considering the spatial distribution characteristics of the local aggregation of the urban population flow and long-term stability characteristics depending on the dynamic changes in entrances and exits.Finally,we divided the FPAZ combined with the microstructural elements.Experimental results showed that compared with other types of PAUs,the FPAZ was more consistent with the urban morphology and was an appropriate and general spatial unit for expressing the accurate characteristics of population distributions and changes at the micro-scale.
基金Project supported by the National Natural Science Foundation of China
文摘The negative secondary ion mass spectrometry,in combination with the stereoselective derivatizations with substituted boronic acid RB(OH)_2,was used in the analysis of fourteen oligosac- charides.The mass spectra of the derivatives provide information on their linkage Positions and iso- merism of the individual monoscaccharide units.The results indicated that among the derivatives of the oligosaccharides analyzed,those with 1—4 and 1—6 linkages all presented the ion peaks at m/z 287,sometimes one more peak at m/z 449.Furthermore,a relationship was found between the linkage positions and the intensity orders of the derivative ions.Finally,the derivatives of the disaccharides with a galactose presented an intense ion peak at m/z 347,and those of oligosaccharides with 1—6 linkage to a galactose at terminal presented the ion at m/z 317.In the case of oligosaccharides with a fructose residue,characteristic ion of m/z 155 was produced.The conditions of stereoselective derivatizations and mass spectrometry were studied,in order to obtain a better reproducibility of the mass spectra.
基金supported in part by a scholarship provided by the Mission DepartmentMinistry of Higher Education of the Government of Egypt
文摘This paper describes the analysis and design of an assistive device for elderly people under development at the EgyptJapan University of Science and Technology(E-JUST) named E-JUST assistive device(EJAD).Several experiments were carried out using a motion capture system(VICON) and inertial sensors to identify the human posture during the sit-to-stand motion.The EJAD uses only two inertial measurement units(IMUs) fused through an adaptive neuro-fuzzy inference systems(ANFIS) algorithm to imitate the real motion of the caregiver.The EJAD consists of two main parts,a robot arm and an active walker.The robot arm is a 2-degree-of-freedom(2-DOF) planar manipulator.In addition,a back support with a passive joint is used to support the patient s back.The IMUs on the leg and trunk of the patient are used to compensate for and adapt to the EJAD system motion depending on the obtained patient posture.The ANFIS algorithm is used to train the fuzzy system that converts the IMUs signals to the right posture of the patient.A control scheme is proposed to control the system motion based on practical measurements taken from the experiments.A computer simulation showed a relatively good performance of the EJAD in assisting the patient.