Fixed Mobile Convergence(FMC)is the focus of the future communications network development,on which the industry has kept strengthening its relevant research.However,before a large scale of implementation,there are st...Fixed Mobile Convergence(FMC)is the focus of the future communications network development,on which the industry has kept strengthening its relevant research.However,before a large scale of implementation,there are still lots of key issues to be explored.The adoption of IP Multimedia Subsystem(IMS)architecture to replace the real-time services in the traditional application needs to solve the Quality of Service(QoS)problem in the IP domain,unify the method that the fixed and mobile users of the traditional circuit domain access IMS,complete the mapping of circuit domain service flow to IMS,guarantee the security of IMS bearer network,transform the traditional operation mode,and set up a new pattern adaptable to the convergence.展开更多
The thermal-induced error is a very important sour ce of machining errors of machine tools. To compensate the thermal-induced machin ing errors, a relationship model between the thermal field and deformations was need...The thermal-induced error is a very important sour ce of machining errors of machine tools. To compensate the thermal-induced machin ing errors, a relationship model between the thermal field and deformations was needed. The relationship can be deduced by virtual of FEM (Finite Element Method ), ANN (Artificial Neural Network) or MRA (Multiple Regression Analysis). MR A is on the basis of a total understanding of the temperature distribution of th e machine tool. Although the more the temperatures measured are, the more accura te the MRA is, too more temperatures will hinder the analysis calculation. So it is necessary to identify the key temperatures of the machine tool. The selectio n of key temperatures decides the efficiency and precision of MRA. Because of th e complexities and multi-input and multi-output structure of the relationships , the exact quantitative portions as well as the unclear portions must be taken into consideration together to improve the identification of key temperatures. I n this paper, a fuzzy cluster analysis was used to select the key temperatures. The substance of identifying the key temperatures is to group all temperatures b y their relativity, and then to select a temperature from each group as the repr esentation. A fuzzy cluster analysis can uncover the relationships between t he thermal field and deformations more truly and thoroughly. A fuzzy cluster ana lysis is the cluster analysis based on fuzzy sets. Given U={u i|i=0,...,N}, in which u i is the temperature measured, a fuzzy matrix R can be obta ined. The transfer close package t(R) can be deduced from R. A fuzzy clu ster of U then conducts on the basis of t(R). Based on the fuzzy cluster analysis discussed above, this paper identified the k ey temperatures of a horizontal machining center. The number of the temperatures measured was reduced to 4 from 32, and then the multiple regression relationshi p models between the 4 temperatures and the thermal deformations of the spindle were drawn. The remnant errors between the regression models and measured deform ations reached a satisfying low level. At the same time, the decreasing of tempe rature variable number improved the efficiency of measure and analysis greatly.展开更多
The foundation quality of construction engineering plays an important role in protecting the safety of users and improving the construction efficiency of superstructure. Nowadays, with the continuous development of bu...The foundation quality of construction engineering plays an important role in protecting the safety of users and improving the construction efficiency of superstructure. Nowadays, with the continuous development of building construction in China towards more beautiful and more floors, ensuring the quality of foundation has become the primary factor. Foundation construction is not only the first step of construction engineering, but also the key step. In order to ensure the quality of foundation construction and avoid building inclination or settlement caused by foundation problems, it is necessary to strictly grasp the quality links and ensure that the construction is completed in accordance with relevant standards. The application of foundation detection technology can ensure that the foundation quality meets the requirements of construction engineering and fundamentally improve the overall quality of construction engineering. Therefore, the application of foundation detection technology in construction engineering is of great significance. In this paper, the author deeply analyzes the key points of foundation detection technology of construction engineering and gives corresponding optimization countermeasures for reference to relevant construction units展开更多
Municipal road engineering in China is a very complicated and systematic engineering, which involves many aspects. Because the flow of people and cars in the city is huge, the construction management of municipal road...Municipal road engineering in China is a very complicated and systematic engineering, which involves many aspects. Because the flow of people and cars in the city is huge, the construction management of municipal roads needs to be combined with multiple urban management departments for communication to ensure the quality of construction management. Therefore, this paper focuses on the analysis of the key points of municipal road construction management for reference.展开更多
Conventional principal component analysis(PCA) can obtain low-dimensional representations of original data space, but the selection of principal components(PCs) based on variance is subjective, which may lead to infor...Conventional principal component analysis(PCA) can obtain low-dimensional representations of original data space, but the selection of principal components(PCs) based on variance is subjective, which may lead to information loss and poor monitoring performance. To address dimension reduction and information preservation simultaneously, this paper proposes a novel PC selection scheme named full variable expression. On the basis of the proposed relevance of variables with each principal component, key principal components can be determined.All the key principal components serve as a low-dimensional representation of the entire original variables, preserving the information of original data space without information loss. A squared Mahalanobis distance, which is introduced as the monitoring statistic, is calculated directly in the key principal component space for fault detection. To test the modeling and monitoring performance of the proposed method, a numerical example and the Tennessee Eastman benchmark are used.展开更多
This study analyzed the prevalent physicochemical phases of smelting slag from the perspective of data science and chemistry.Findings delineated the silicate phase as the pivotal and predominant constraining phase for...This study analyzed the prevalent physicochemical phases of smelting slag from the perspective of data science and chemistry.Findings delineated the silicate phase as the pivotal and predominant constraining phase for the resource utilization of smelting slag.An intricate correlation between metallic elements and dominant phases was constructed.Typical silicate phase olivine(OL)was synthesized as a paradigm to examine alkali depolymerization,unveiling the optimal conditions for such depolymerization to be an alkali to olivine molar ratio of 1:5,a reaction temperature of 700℃,and a duration of 3 h.The underlying mechanism of alkali depolymerization within silicate phases was elucidated under these parameters.The reaction mechanism of alkali depolymerization within silicate phases can be encapsulated in three sequential steps:(1)NaOH dissociation and subsequent adsorption of OH^(-)to cationic(Mg or Fe)sites;(2)disruption of cation-oxygen bonds,leading to the formation of hydroxide compounds,which then underwent oxidation;(3)Na^(+)occupied the resultant cation vacancy sites,instigating further depolymerization of the intermediate Na_(2)(Mg,Fe)SiO_(4).The articulated mechanism is anticipated to furnish theoretical underpinnings for the efficacious recuperation of metals from smelting slags.展开更多
Seedling nursery is the end of the whole nursery in the nursery, and good technology can guarantee the survival rate and growth quality of seedlings. Therefore, to ensure healthy nursery, must pay attention to seedlin...Seedling nursery is the end of the whole nursery in the nursery, and good technology can guarantee the survival rate and growth quality of seedlings. Therefore, to ensure healthy nursery, must pay attention to seedling quality inspection, strictly follow the relevant inspection standards, and combined with the actual situation of nursery technical points, strictly do seedling early cultivation, investigation, seedling method selection, seedling disinfection and transportation, and strictly control the management of nursery, to meet the needs of nursery.展开更多
With the continuous progress of society, the level of national economy has been greatly improved, and the process of urbanization has been accelerated. Electric power is the main basic energy in our country, has been ...With the continuous progress of society, the level of national economy has been greatly improved, and the process of urbanization has been accelerated. Electric power is the main basic energy in our country, has been an indispensable energy for social and economic development, and plays an important role in people's daily production and life. However, due to various factors, distribution and electrical engineering can lead to the loss of wires, thus affecting the improvement of power quality. This paper first analyzes the causes of line loss in transmission and distribution engineering, and then further discusses the key points of line loss management in transmission and distribution engineering.展开更多
Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ...Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.展开更多
This study introduces a comprehensive and automated framework that leverages data-driven method-ologies to address various challenges in shale gas development and production.Specifically,it harnesses the power of Auto...This study introduces a comprehensive and automated framework that leverages data-driven method-ologies to address various challenges in shale gas development and production.Specifically,it harnesses the power of Automated Machine Learning(AutoML)to construct an ensemble model to predict the estimated ultimate recovery(EUR)of shale gas wells.To demystify the“black-box”nature of the ensemble model,KernelSHAP,a kernel-based approach to compute Shapley values,is utilized for elucidating the influential factors that affect shale gas production at both global and local scales.Furthermore,a bi-objective optimization algorithm named NSGA-Ⅱ is seamlessly incorporated to opti-mize hydraulic fracturing designs for production boost and cost control.This innovative framework addresses critical limitations often encountered in applying machine learning(ML)to shale gas pro-duction:the challenge of achieving sufficient model accuracy with limited samples,the multidisciplinary expertise required for developing robust ML models,and the need for interpretability in“black-box”models.Validation with field data from the Fuling shale gas field in the Sichuan Basin substantiates the framework's efficacy in enhancing the precision and applicability of data-driven techniques.The test accuracy of the ensemble ML model reached 83%compared to a maximum of 72%of single ML models.The contribution of each geological and engineering factor to the overall production was quantitatively evaluated.Fracturing design optimization raised EUR by 7%-34%under different production and cost tradeoff scenarios.The results empower domain experts to conduct more precise and objective data-driven analyses and optimizations for shale gas production with minimal expertise in data science.展开更多
This paper proposes to develop a data-driven via＇s depth estimator of the deep reactive ion etching process based on statistical identification of key variables.Several feature extraction algorithms are presented to ...This paper proposes to develop a data-driven via＇s depth estimator of the deep reactive ion etching process based on statistical identification of key variables.Several feature extraction algorithms are presented to reduce the high-dimensional data and effectively undertake the subsequent virtual metrology（VM） model building process.With the available on-line VM model,the model-based controller is hence readily applicable to improve the quality of a via＇s depth.Real operational data taken from a industrial manufacturing process are used to verify the effectiveness of the proposed method.The results demonstrate that the proposed method can decrease the MSE from 2.2×10^（-2） to 9×10^（-4） and has great potential in improving the existing DRIE process.展开更多
China is rich in minerals. At present, coal shearer and synthetic equipment are mainly used in coal mining. Fully consider the actual production situation and the technical basis, realize the reasonable automatic extr...China is rich in minerals. At present, coal shearer and synthetic equipment are mainly used in coal mining. Fully consider the actual production situation and the technical basis, realize the reasonable automatic extraction technology of three machines, develop the whole working face centralized production automation system suitable for coal-bed methane mining technology and better solve the problem of safe and efficient automatic extraction of working face.展开更多
As we all know, the earthquake disaster has brought huge losses to society, enterprises and individuals, which can lead to the collapse of houses and buildings, the destruction of infrastructure and equipment in traff...As we all know, the earthquake disaster has brought huge losses to society, enterprises and individuals, which can lead to the collapse of houses and buildings, the destruction of infrastructure and equipment in traffic construction, and even cause a large number of casualties, which has a serious impact on social development and people's daily life. Therefore, it is necessary to strengthen the research on the seismic design technology and reinforcement methods of building structures, constantly improve the seismic capacity of building structures, minimize the building collapse caused by earthquake disasters, and ensure the safety of people's lives and property.展开更多
文摘Fixed Mobile Convergence(FMC)is the focus of the future communications network development,on which the industry has kept strengthening its relevant research.However,before a large scale of implementation,there are still lots of key issues to be explored.The adoption of IP Multimedia Subsystem(IMS)architecture to replace the real-time services in the traditional application needs to solve the Quality of Service(QoS)problem in the IP domain,unify the method that the fixed and mobile users of the traditional circuit domain access IMS,complete the mapping of circuit domain service flow to IMS,guarantee the security of IMS bearer network,transform the traditional operation mode,and set up a new pattern adaptable to the convergence.
文摘The thermal-induced error is a very important sour ce of machining errors of machine tools. To compensate the thermal-induced machin ing errors, a relationship model between the thermal field and deformations was needed. The relationship can be deduced by virtual of FEM (Finite Element Method ), ANN (Artificial Neural Network) or MRA (Multiple Regression Analysis). MR A is on the basis of a total understanding of the temperature distribution of th e machine tool. Although the more the temperatures measured are, the more accura te the MRA is, too more temperatures will hinder the analysis calculation. So it is necessary to identify the key temperatures of the machine tool. The selectio n of key temperatures decides the efficiency and precision of MRA. Because of th e complexities and multi-input and multi-output structure of the relationships , the exact quantitative portions as well as the unclear portions must be taken into consideration together to improve the identification of key temperatures. I n this paper, a fuzzy cluster analysis was used to select the key temperatures. The substance of identifying the key temperatures is to group all temperatures b y their relativity, and then to select a temperature from each group as the repr esentation. A fuzzy cluster analysis can uncover the relationships between t he thermal field and deformations more truly and thoroughly. A fuzzy cluster ana lysis is the cluster analysis based on fuzzy sets. Given U={u i|i=0,...,N}, in which u i is the temperature measured, a fuzzy matrix R can be obta ined. The transfer close package t(R) can be deduced from R. A fuzzy clu ster of U then conducts on the basis of t(R). Based on the fuzzy cluster analysis discussed above, this paper identified the k ey temperatures of a horizontal machining center. The number of the temperatures measured was reduced to 4 from 32, and then the multiple regression relationshi p models between the 4 temperatures and the thermal deformations of the spindle were drawn. The remnant errors between the regression models and measured deform ations reached a satisfying low level. At the same time, the decreasing of tempe rature variable number improved the efficiency of measure and analysis greatly.
文摘The foundation quality of construction engineering plays an important role in protecting the safety of users and improving the construction efficiency of superstructure. Nowadays, with the continuous development of building construction in China towards more beautiful and more floors, ensuring the quality of foundation has become the primary factor. Foundation construction is not only the first step of construction engineering, but also the key step. In order to ensure the quality of foundation construction and avoid building inclination or settlement caused by foundation problems, it is necessary to strictly grasp the quality links and ensure that the construction is completed in accordance with relevant standards. The application of foundation detection technology can ensure that the foundation quality meets the requirements of construction engineering and fundamentally improve the overall quality of construction engineering. Therefore, the application of foundation detection technology in construction engineering is of great significance. In this paper, the author deeply analyzes the key points of foundation detection technology of construction engineering and gives corresponding optimization countermeasures for reference to relevant construction units
文摘Municipal road engineering in China is a very complicated and systematic engineering, which involves many aspects. Because the flow of people and cars in the city is huge, the construction management of municipal roads needs to be combined with multiple urban management departments for communication to ensure the quality of construction management. Therefore, this paper focuses on the analysis of the key points of municipal road construction management for reference.
基金Supported by the National Natural Science Foundation of China(No.61374140)Shanghai Pujiang Program(Project No.12PJ1402200)
文摘Conventional principal component analysis(PCA) can obtain low-dimensional representations of original data space, but the selection of principal components(PCs) based on variance is subjective, which may lead to information loss and poor monitoring performance. To address dimension reduction and information preservation simultaneously, this paper proposes a novel PC selection scheme named full variable expression. On the basis of the proposed relevance of variables with each principal component, key principal components can be determined.All the key principal components serve as a low-dimensional representation of the entire original variables, preserving the information of original data space without information loss. A squared Mahalanobis distance, which is introduced as the monitoring statistic, is calculated directly in the key principal component space for fault detection. To test the modeling and monitoring performance of the proposed method, a numerical example and the Tennessee Eastman benchmark are used.
基金financially supported by the National Natural Science Foundation of China(Nos.22006040 and 22376070)the National Key Research and Development Program of China(No.2019YFA0210404)the Research Project on Characteristic Innovation of University Teachers(No.2022XJZZ02)。
文摘This study analyzed the prevalent physicochemical phases of smelting slag from the perspective of data science and chemistry.Findings delineated the silicate phase as the pivotal and predominant constraining phase for the resource utilization of smelting slag.An intricate correlation between metallic elements and dominant phases was constructed.Typical silicate phase olivine(OL)was synthesized as a paradigm to examine alkali depolymerization,unveiling the optimal conditions for such depolymerization to be an alkali to olivine molar ratio of 1:5,a reaction temperature of 700℃,and a duration of 3 h.The underlying mechanism of alkali depolymerization within silicate phases was elucidated under these parameters.The reaction mechanism of alkali depolymerization within silicate phases can be encapsulated in three sequential steps:(1)NaOH dissociation and subsequent adsorption of OH^(-)to cationic(Mg or Fe)sites;(2)disruption of cation-oxygen bonds,leading to the formation of hydroxide compounds,which then underwent oxidation;(3)Na^(+)occupied the resultant cation vacancy sites,instigating further depolymerization of the intermediate Na_(2)(Mg,Fe)SiO_(4).The articulated mechanism is anticipated to furnish theoretical underpinnings for the efficacious recuperation of metals from smelting slags.
文摘Seedling nursery is the end of the whole nursery in the nursery, and good technology can guarantee the survival rate and growth quality of seedlings. Therefore, to ensure healthy nursery, must pay attention to seedling quality inspection, strictly follow the relevant inspection standards, and combined with the actual situation of nursery technical points, strictly do seedling early cultivation, investigation, seedling method selection, seedling disinfection and transportation, and strictly control the management of nursery, to meet the needs of nursery.
文摘With the continuous progress of society, the level of national economy has been greatly improved, and the process of urbanization has been accelerated. Electric power is the main basic energy in our country, has been an indispensable energy for social and economic development, and plays an important role in people's daily production and life. However, due to various factors, distribution and electrical engineering can lead to the loss of wires, thus affecting the improvement of power quality. This paper first analyzes the causes of line loss in transmission and distribution engineering, and then further discusses the key points of line loss management in transmission and distribution engineering.
文摘Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.
基金funded by the National Natural Science Foundation of China(42050104).
文摘This study introduces a comprehensive and automated framework that leverages data-driven method-ologies to address various challenges in shale gas development and production.Specifically,it harnesses the power of Automated Machine Learning(AutoML)to construct an ensemble model to predict the estimated ultimate recovery(EUR)of shale gas wells.To demystify the“black-box”nature of the ensemble model,KernelSHAP,a kernel-based approach to compute Shapley values,is utilized for elucidating the influential factors that affect shale gas production at both global and local scales.Furthermore,a bi-objective optimization algorithm named NSGA-Ⅱ is seamlessly incorporated to opti-mize hydraulic fracturing designs for production boost and cost control.This innovative framework addresses critical limitations often encountered in applying machine learning(ML)to shale gas pro-duction:the challenge of achieving sufficient model accuracy with limited samples,the multidisciplinary expertise required for developing robust ML models,and the need for interpretability in“black-box”models.Validation with field data from the Fuling shale gas field in the Sichuan Basin substantiates the framework's efficacy in enhancing the precision and applicability of data-driven techniques.The test accuracy of the ensemble ML model reached 83%compared to a maximum of 72%of single ML models.The contribution of each geological and engineering factor to the overall production was quantitatively evaluated.Fracturing design optimization raised EUR by 7%-34%under different production and cost tradeoff scenarios.The results empower domain experts to conduct more precise and objective data-driven analyses and optimizations for shale gas production with minimal expertise in data science.
基金supported by the National Natural Science Foundation of China(No.60904053)the Natural Science Foundation of Jiangsu(No. SBK201123307)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘This paper proposes to develop a data-driven via＇s depth estimator of the deep reactive ion etching process based on statistical identification of key variables.Several feature extraction algorithms are presented to reduce the high-dimensional data and effectively undertake the subsequent virtual metrology（VM） model building process.With the available on-line VM model,the model-based controller is hence readily applicable to improve the quality of a via＇s depth.Real operational data taken from a industrial manufacturing process are used to verify the effectiveness of the proposed method.The results demonstrate that the proposed method can decrease the MSE from 2.2×10^（-2） to 9×10^（-4） and has great potential in improving the existing DRIE process.
文摘China is rich in minerals. At present, coal shearer and synthetic equipment are mainly used in coal mining. Fully consider the actual production situation and the technical basis, realize the reasonable automatic extraction technology of three machines, develop the whole working face centralized production automation system suitable for coal-bed methane mining technology and better solve the problem of safe and efficient automatic extraction of working face.
文摘As we all know, the earthquake disaster has brought huge losses to society, enterprises and individuals, which can lead to the collapse of houses and buildings, the destruction of infrastructure and equipment in traffic construction, and even cause a large number of casualties, which has a serious impact on social development and people's daily life. Therefore, it is necessary to strengthen the research on the seismic design technology and reinforcement methods of building structures, constantly improve the seismic capacity of building structures, minimize the building collapse caused by earthquake disasters, and ensure the safety of people's lives and property.
