Quality traceability plays an essential role in assembling and welding offshore platform blocks.The improvement of the welding quality traceability system is conducive to improving the durability of the offshore platf...Quality traceability plays an essential role in assembling and welding offshore platform blocks.The improvement of the welding quality traceability system is conducive to improving the durability of the offshore platform and the process level of the offshore industry.Currently,qualitymanagement remains in the era of primary information,and there is a lack of effective tracking and recording of welding quality data.When welding defects are encountered,it is difficult to rapidly and accurately determine the root cause of the problem from various complexities and scattered quality data.In this paper,a composite welding quality traceability model for offshore platform block construction process is proposed,it contains the quality early-warning method based on long short-term memory and quality data backtracking query optimization algorithm.By fulfilling the training of the early-warning model and the implementation of the query optimization algorithm,the quality traceability model has the ability to assist enterprises in realizing the rapid identification and positioning of quality problems.Furthermore,the model and the quality traceability algorithm are checked by cases in actual working conditions.Verification analyses suggest that the proposed early-warningmodel for welding quality and the algorithmfor optimizing backtracking requests are effective and can be applied to the actual construction process.展开更多
A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the u...A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the ultimate equilibrium method. Based on the results of finite element analysis, the stress contour graphs and displacement vector graphs at different construction steps were obtained, and the behavior of the slope during stabilization construction process was analyzed quantitatively. Based on the analysis of safety factors of three different schemes of stabilization and two different construction schemes, the assessment of stability and bracing design of the construction process were performed. The results show that the original reinforcement design is improper; the stability of the rock slope is controlled by a developed structural plane, the stability factor after excavation is less than 1, and the free surface should be braced in time; for stability, the construction sequence should adopt that bracing follows excavation step by step up to down; the local slide occurred during the construction process agrees with the dangerous slide determined by the numerical analysis, which proves the validity and rationality of the adopted method.展开更多
In the ISO9000"input-output"process model,the concept of process quality is difficult to get the correct interpretation. From the"white box"theory of process,this paper puts forward the scientific ...In the ISO9000"input-output"process model,the concept of process quality is difficult to get the correct interpretation. From the"white box"theory of process,this paper puts forward the scientific meaning of the concept of process quality and the process quality model by taking the basic operating unit of 6M1E in the railway construction project for example. The basic operating unit system consists of technological natural process,operation process and management process;the process quality of the basic operating unit system depends on the interrelation and interaction among those three sub-processes,and also subjects to the impact of the external disturbance input factors. Finally,the cast-in-situ prestressed concrete continuous box girder construction process is utilized to elaborate the specific application of this theory in the quality management of the railway construction project.展开更多
The leaning of structures happens all around the world and generates impacts on different extents;thus, it is important to learn about the causes behind. In this report, the sequential construction of a typical leanin...The leaning of structures happens all around the world and generates impacts on different extents;thus, it is important to learn about the causes behind. In this report, the sequential construction of a typical leaning structure, the Tower of Pisa, is discussed and simulated by using a finite element code, PLAXIS. The simulation is performed on a two-dimensional plane with simplifications taken into consideration in making modeling feasible under limitations. Three distinct models are built with one as a control variable, while the other two models are set up with exact eccentricity. Data are obtained from the analysis and are plotted in a graph to clearly show the relationship between the tilting angle and construction phases. With reasonable and completed simulation, the study is able to show the significant role compressible subsoil plays in impacting the tilting performance of a tall building.展开更多
In recent years,with the rapid development of modern social economy,the urbanization process has continued to grow,and with it,so as to the demand for housing construction in urban areas.From the development perspecti...In recent years,with the rapid development of modern social economy,the urbanization process has continued to grow,and with it,so as to the demand for housing construction in urban areas.From the development perspective of construction projects,the construction involved would not only has to have a strong structural quality,but attention is also needed in the overall quality of the building.In this,a reasonable introduction of post-pouring belt construction technology in the building construction process can effectively control cracks in concrete structures.This article takes the post-pouring belt construction technology as the main research object and focuses on its application in the housing construction process,which has shown to provide better assistance in aiding construction.展开更多
The construction of water supply and drainage pipelines is a very important part of municipal construction.The construction of HDPE pipe has been widely used in the construction field of water supply and drainage pipe...The construction of water supply and drainage pipelines is a very important part of municipal construction.The construction of HDPE pipe has been widely used in the construction field of water supply and drainage pipelines due to its many advantages.Therefore,the construction process of HDPE pipe has also been studied more and more in the construction of municipal water supply and drainage,which is of great significance for the application of HDPE in municipal water supply and drainage construction.This paper analyzes the HDPE pipe construction process of municipal water supply and drainage construction workers,and hopes to help the good application of HDPE pipe and the improvement of municipal water supply and drainage construction quality.展开更多
Quality is the life of architecture.Without quality there is nothing.Engineering projects have the characteristics of large investment and long construction period,so the quality of construction projects must be stric...Quality is the life of architecture.Without quality there is nothing.Engineering projects have the characteristics of large investment and long construction period,so the quality of construction projects must be strictly controlled.The control of construction quality of engineering projects is the quality control of the whole process and the participation of all employees.It is the implementation of construction engineering quality regulations and mandatory standards,the correct configuration of construction production management elements and the use of scientific management methods to achieve the expected use function of engineering projects And quality standards,deliver the owner a satisfactory quality project.Most of the quality problems of construction projects appear in the construction stage.Therefore,we must strictly control the quality in project construction,strengthen the whole process management from the organization and management,find a project quality management system suitable for China’s national conditions,and be able to eliminate the hidden quality hazards in the project in time to ensure the project The construction project can meet the target requirements,and the project quality can be effectively controlled.This article mainly analyzes the current problems affecting the construction quality,combined with the actual analysis,and then find some countermeasures to solve the problem.展开更多
The building sector plays a key role in the global economic,social,and environment development.The energy consumed during construction and operation processes accounts for around 40%of the global energy use.China is t...The building sector plays a key role in the global economic,social,and environment development.The energy consumed during construction and operation processes accounts for around 40%of the global energy use.China is the largest developing country and its construction market is one of the largest markets in the world.Although the construction phase occupies only a short period over the entire life cycle of a building,it is still an essential aspect of the process.However,in China,the concept of green construction remains scarcely known among construction industry members.Green construction continues to experience a disparity in the Chinese construction industry.Therefore,the aim of this study is to appraise the concept of green construction in the Chinese construction industry and to consider how it could be applied in most Chinese construction projects.展开更多
Applying stiffness migration method,a 3D finite element mechanical model is established to simulate the excavation and advance processes.By using 3D nonlinear finite element method,the tunnel boring machine(TBM) excav...Applying stiffness migration method,a 3D finite element mechanical model is established to simulate the excavation and advance processes.By using 3D nonlinear finite element method,the tunnel boring machine(TBM) excavation process is dynamically simulated to analyze the stress and strain field status of surrounding rock and segment.The maximum tensile stress of segment ring caused by tunnel construction mainly lies in arch bottom and presents zonal distribution.The stress increases slightly and limitedly in the course of excavation.The maximum and minimum displacements of segment,manifesting as zonal distribution,distribute in arch bottom and vault respectively.The displacements slightly increase with the advance of TBM and gradually tend to stability.展开更多
Long tunnel excavation with tunnel boring machine (TBM) is a complex and stochastic process. It is easily affected by uncertainties and needs to be adjusted according to specific geological conditions in different tun...Long tunnel excavation with tunnel boring machine (TBM) is a complex and stochastic process. It is easily affected by uncertainties and needs to be adjusted according to specific geological conditions in different tunnel sections, which makes the construction scheduling and management difficult. Based on the rock mass classification, this paper estimates the penetration rate. Using the rate, a cyclic network simulation (CYCLONE) model of TBM boring system is established, and the advance rates under different geological conditions are determined. Then, the impact of different cutter head thrust, which is chosen in reasonable range according to previous experiences, on project schedule is analyzed. Moreover, the simulation model of mucking system is built to determine the number of muck trains and rail intersections reasonably, regarding the efficiency of muck loading and material transporting. Based on the interaction and interrelation between TBM boring system and mucking system, the combined CYCLONE model for the entire tunneling process is established. Then reasonable construction schedule, the utilization rate of working resources, and the probability of project completion are obtained through the model programming. At last, a project application shows the feasibility of the presented method.展开更多
In recent years,China has made significant progress in the construction of highways,resulting in an improved highway network that has provided robust support for economic and social development.However,the rapid expan...In recent years,China has made significant progress in the construction of highways,resulting in an improved highway network that has provided robust support for economic and social development.However,the rapid expansion of highway construction,power supply,and distribution has led to several challenges in mechanical and electrical engineering technology.Ensuring the safe,stable,and cost-effective operation of the power supply and distribution system to meet the diverse requirements of highway operations has become a pressing issue.This article takes an example of a highway electromechanical engineering power supply and distribution construction project to provide insight into the construction process of highway electromechanical engineering power supply and distribution technology.展开更多
The design process of the built environment relies on the collaborative effort of all parties involved in the project.During the design phase,owners,end users,and their representatives are expected to make the most cr...The design process of the built environment relies on the collaborative effort of all parties involved in the project.During the design phase,owners,end users,and their representatives are expected to make the most critical design and budgetary decisions-shaping the essential traits of the project,hence emerge the need and necessity to create and integrate mechanisms to support the decision-making process.Design decisions should not be based on assumptions,past experiences,or imagination.An example of the numerous problems that are a result of uninformed design decisions is“change orders”,known as the deviation from the original scope of work,which leads to an increase of the overall cost,and changes to the construction schedule of the project.The long-term aim of this inquiry is to understand the user’s behavior,and establish evidence-based control measures,which are actions and processes that can be implemented in practice to decrease the volume and frequency of the occurrence of change orders.The current study developed a foundation for further examination by proposing potential control measures,and testing their efficiency,such as integrating Virtual Reality(VR).The specific aim was to examine the effect of different visualization methods(i.e.,VR vs.construction drawings)on,(1)how well the subjects understand the information presented about the future/planned environment;(2)the subjects’perceived confidence in what the future environment will look like;(3)the likelihood of changing the built environment;(4)design review time;and(5)accuracy in reviewing and understanding the design.展开更多
Numerical simulation is the most powerful computational and analysis tool for a large variety of engineering and physical problems.For a complex problem relating to multi-field,multi-process and multi-scale,different ...Numerical simulation is the most powerful computational and analysis tool for a large variety of engineering and physical problems.For a complex problem relating to multi-field,multi-process and multi-scale,different computing tools have to be developed so as to solve particular fields at different scales and for different processes.Therefore,the integration of different types of software is inevitable.However,it is difficult to perform the transfer of the meshes and simulated results among software packages because of the lack of shared data formats or encrypted data formats.An image processing based method for three-dimensional model reconstruction for numerical simulation was proposed,which presents a solution to the integration problem by a series of slice or projection images obtained by the post-processing modules of the numerical simulation software.By means of mapping image pixels to meshes of either finite difference or finite element models,the geometry contour can be extracted to export the stereolithography model.The values of results,represented by color,can be deduced and assigned to the meshes.All the models with data can be directly or indirectly integrated into other software as a continued or new numerical simulation.The three-dimensional reconstruction method has been validated in numerical simulation of castings and case studies were provided in this study.展开更多
Objective To study how to improve and perfect the information platform and processing mechanism of drug shortages in China.Methods By searching the relevant policies from official websites of FDA,European Medicines Ag...Objective To study how to improve and perfect the information platform and processing mechanism of drug shortages in China.Methods By searching the relevant policies from official websites of FDA,European Medicines Agency(EMA),Health Canada(HC)and National Health Commission,the good experience of the United States,the European Union and Canada in the construction of information platform and processing mechanism of drug shortages was summarized for reference in China.Results and Conclusion China has initially established the processing mechanism of drug shortages,but the platform construction should be improved,and the information disclosure of drug shortages varies from province to province.We should improve the information platform of drug shortages,strengthen the disclosure and communication of information,enrich the processing tools and measures after the drug shortages occurs,and strengthen the cooperation with relevant associations and other non-governmental departments.展开更多
In order to clarify the direction and way of construction enterprise culture,the method of construction enterprise culture based on quality function deployment(QFD)theory is put forward.Firstly,the paper analyzes the ...In order to clarify the direction and way of construction enterprise culture,the method of construction enterprise culture based on quality function deployment(QFD)theory is put forward.Firstly,the paper analyzes the QFD theory and the forming process of construction enterprise culture and considers that the two have strong adaptability in the aspects of basic characteristics,implementation process,and logical relationship.Secondly,based on QFD,the basic framework of construction enterprise culture is established,which is divided into three stages:cultural planning,process planning,and implementation planning.Finally,the paper expounds on each link of the cultural planning matrix in detail.展开更多
This survey paper provides a review and perspective on intermediate and advanced reinforcement learning(RL)techniques in process industries. It offers a holistic approach by covering all levels of the process control ...This survey paper provides a review and perspective on intermediate and advanced reinforcement learning(RL)techniques in process industries. It offers a holistic approach by covering all levels of the process control hierarchy. The survey paper presents a comprehensive overview of RL algorithms,including fundamental concepts like Markov decision processes and different approaches to RL, such as value-based, policy-based, and actor-critic methods, while also discussing the relationship between classical control and RL. It further reviews the wide-ranging applications of RL in process industries, such as soft sensors, low-level control, high-level control, distributed process control, fault detection and fault tolerant control, optimization,planning, scheduling, and supply chain. The survey paper discusses the limitations and advantages, trends and new applications, and opportunities and future prospects for RL in process industries. Moreover, it highlights the need for a holistic approach in complex systems due to the growing importance of digitalization in the process industries.展开更多
We study the Nadaraya-Watson estimators for the drift function of two-sided reflected stochastic differential equations.The estimates,based on either the continuously observed process or the discretely observed proces...We study the Nadaraya-Watson estimators for the drift function of two-sided reflected stochastic differential equations.The estimates,based on either the continuously observed process or the discretely observed process,are considered.Under certain conditions,we prove the strong consistency and the asymptotic normality of the two estimators.Our method is also suitable for one-sided reflected stochastic differential equations.Simulation results demonstrate that the performance of our estimator is superior to that of the estimator proposed by Cholaquidis et al.(Stat Sin,2021,31:29-51).Several real data sets of the currency exchange rate are used to illustrate our proposed methodology.展开更多
Oscillation detection has been a hot research topic in industries due to the high incidence of oscillation loops and their negative impact on plant profitability.Although numerous automatic detection techniques have b...Oscillation detection has been a hot research topic in industries due to the high incidence of oscillation loops and their negative impact on plant profitability.Although numerous automatic detection techniques have been proposed,most of them can only address part of the practical difficulties.An oscillation is heuristically defined as a visually apparent periodic variation.However,manual visual inspection is labor-intensive and prone to missed detection.Convolutional neural networks(CNNs),inspired by animal visual systems,have been raised with powerful feature extraction capabilities.In this work,an exploration of the typical CNN models for visual oscillation detection is performed.Specifically,we tested MobileNet-V1,ShuffleNet-V2,Efficient Net-B0,and GhostNet models,and found that such a visual framework is well-suited for oscillation detection.The feasibility and validity of this framework are verified utilizing extensive numerical and industrial cases.Compared with state-of-theart oscillation detectors,the suggested framework is more straightforward and more robust to noise and mean-nonstationarity.In addition,this framework generalizes well and is capable of handling features that are not present in the training data,such as multiple oscillations and outliers.展开更多
基金funded by Ministry of Industry and Information Technology of the People’s Republic of China[Grant No.2018473].
文摘Quality traceability plays an essential role in assembling and welding offshore platform blocks.The improvement of the welding quality traceability system is conducive to improving the durability of the offshore platform and the process level of the offshore industry.Currently,qualitymanagement remains in the era of primary information,and there is a lack of effective tracking and recording of welding quality data.When welding defects are encountered,it is difficult to rapidly and accurately determine the root cause of the problem from various complexities and scattered quality data.In this paper,a composite welding quality traceability model for offshore platform block construction process is proposed,it contains the quality early-warning method based on long short-term memory and quality data backtracking query optimization algorithm.By fulfilling the training of the early-warning model and the implementation of the query optimization algorithm,the quality traceability model has the ability to assist enterprises in realizing the rapid identification and positioning of quality problems.Furthermore,the model and the quality traceability algorithm are checked by cases in actual working conditions.Verification analyses suggest that the proposed early-warningmodel for welding quality and the algorithmfor optimizing backtracking requests are effective and can be applied to the actual construction process.
基金Scientific and Technological Support and Guidance Plan Projects of Zhejiang Province(Grant No.2008C23019)
文摘A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the ultimate equilibrium method. Based on the results of finite element analysis, the stress contour graphs and displacement vector graphs at different construction steps were obtained, and the behavior of the slope during stabilization construction process was analyzed quantitatively. Based on the analysis of safety factors of three different schemes of stabilization and two different construction schemes, the assessment of stability and bracing design of the construction process were performed. The results show that the original reinforcement design is improper; the stability of the rock slope is controlled by a developed structural plane, the stability factor after excavation is less than 1, and the free surface should be braced in time; for stability, the construction sequence should adopt that bracing follows excavation step by step up to down; the local slide occurred during the construction process agrees with the dangerous slide determined by the numerical analysis, which proves the validity and rationality of the adopted method.
基金Key Subject of Ministry of Railway Technology Research and Development Program(No.2011G010-D)Central University Funds for Basic Research(No.SWJTU12ZT12)
文摘In the ISO9000"input-output"process model,the concept of process quality is difficult to get the correct interpretation. From the"white box"theory of process,this paper puts forward the scientific meaning of the concept of process quality and the process quality model by taking the basic operating unit of 6M1E in the railway construction project for example. The basic operating unit system consists of technological natural process,operation process and management process;the process quality of the basic operating unit system depends on the interrelation and interaction among those three sub-processes,and also subjects to the impact of the external disturbance input factors. Finally,the cast-in-situ prestressed concrete continuous box girder construction process is utilized to elaborate the specific application of this theory in the quality management of the railway construction project.
文摘The leaning of structures happens all around the world and generates impacts on different extents;thus, it is important to learn about the causes behind. In this report, the sequential construction of a typical leaning structure, the Tower of Pisa, is discussed and simulated by using a finite element code, PLAXIS. The simulation is performed on a two-dimensional plane with simplifications taken into consideration in making modeling feasible under limitations. Three distinct models are built with one as a control variable, while the other two models are set up with exact eccentricity. Data are obtained from the analysis and are plotted in a graph to clearly show the relationship between the tilting angle and construction phases. With reasonable and completed simulation, the study is able to show the significant role compressible subsoil plays in impacting the tilting performance of a tall building.
文摘In recent years,with the rapid development of modern social economy,the urbanization process has continued to grow,and with it,so as to the demand for housing construction in urban areas.From the development perspective of construction projects,the construction involved would not only has to have a strong structural quality,but attention is also needed in the overall quality of the building.In this,a reasonable introduction of post-pouring belt construction technology in the building construction process can effectively control cracks in concrete structures.This article takes the post-pouring belt construction technology as the main research object and focuses on its application in the housing construction process,which has shown to provide better assistance in aiding construction.
文摘The construction of water supply and drainage pipelines is a very important part of municipal construction.The construction of HDPE pipe has been widely used in the construction field of water supply and drainage pipelines due to its many advantages.Therefore,the construction process of HDPE pipe has also been studied more and more in the construction of municipal water supply and drainage,which is of great significance for the application of HDPE in municipal water supply and drainage construction.This paper analyzes the HDPE pipe construction process of municipal water supply and drainage construction workers,and hopes to help the good application of HDPE pipe and the improvement of municipal water supply and drainage construction quality.
文摘Quality is the life of architecture.Without quality there is nothing.Engineering projects have the characteristics of large investment and long construction period,so the quality of construction projects must be strictly controlled.The control of construction quality of engineering projects is the quality control of the whole process and the participation of all employees.It is the implementation of construction engineering quality regulations and mandatory standards,the correct configuration of construction production management elements and the use of scientific management methods to achieve the expected use function of engineering projects And quality standards,deliver the owner a satisfactory quality project.Most of the quality problems of construction projects appear in the construction stage.Therefore,we must strictly control the quality in project construction,strengthen the whole process management from the organization and management,find a project quality management system suitable for China’s national conditions,and be able to eliminate the hidden quality hazards in the project in time to ensure the project The construction project can meet the target requirements,and the project quality can be effectively controlled.This article mainly analyzes the current problems affecting the construction quality,combined with the actual analysis,and then find some countermeasures to solve the problem.
文摘The building sector plays a key role in the global economic,social,and environment development.The energy consumed during construction and operation processes accounts for around 40%of the global energy use.China is the largest developing country and its construction market is one of the largest markets in the world.Although the construction phase occupies only a short period over the entire life cycle of a building,it is still an essential aspect of the process.However,in China,the concept of green construction remains scarcely known among construction industry members.Green construction continues to experience a disparity in the Chinese construction industry.Therefore,the aim of this study is to appraise the concept of green construction in the Chinese construction industry and to consider how it could be applied in most Chinese construction projects.
基金Supported by National Natural Science Foundation of China(No.90815019)National Key Basic Research Program of China("973" Program,No.2007CB714101)Key Project in the National Science and Technology Pillar Program during the Eleventh Five-Year Plan Period(No.2006BAB04A13)
文摘Applying stiffness migration method,a 3D finite element mechanical model is established to simulate the excavation and advance processes.By using 3D nonlinear finite element method,the tunnel boring machine(TBM) excavation process is dynamically simulated to analyze the stress and strain field status of surrounding rock and segment.The maximum tensile stress of segment ring caused by tunnel construction mainly lies in arch bottom and presents zonal distribution.The stress increases slightly and limitedly in the course of excavation.The maximum and minimum displacements of segment,manifesting as zonal distribution,distribute in arch bottom and vault respectively.The displacements slightly increase with the advance of TBM and gradually tend to stability.
基金Supported by National Natural Science Foundation of China (No.50709024)Program for New Century Excellent Talents in University (No. NCET-08-0391)
文摘Long tunnel excavation with tunnel boring machine (TBM) is a complex and stochastic process. It is easily affected by uncertainties and needs to be adjusted according to specific geological conditions in different tunnel sections, which makes the construction scheduling and management difficult. Based on the rock mass classification, this paper estimates the penetration rate. Using the rate, a cyclic network simulation (CYCLONE) model of TBM boring system is established, and the advance rates under different geological conditions are determined. Then, the impact of different cutter head thrust, which is chosen in reasonable range according to previous experiences, on project schedule is analyzed. Moreover, the simulation model of mucking system is built to determine the number of muck trains and rail intersections reasonably, regarding the efficiency of muck loading and material transporting. Based on the interaction and interrelation between TBM boring system and mucking system, the combined CYCLONE model for the entire tunneling process is established. Then reasonable construction schedule, the utilization rate of working resources, and the probability of project completion are obtained through the model programming. At last, a project application shows the feasibility of the presented method.
文摘In recent years,China has made significant progress in the construction of highways,resulting in an improved highway network that has provided robust support for economic and social development.However,the rapid expansion of highway construction,power supply,and distribution has led to several challenges in mechanical and electrical engineering technology.Ensuring the safe,stable,and cost-effective operation of the power supply and distribution system to meet the diverse requirements of highway operations has become a pressing issue.This article takes an example of a highway electromechanical engineering power supply and distribution construction project to provide insight into the construction process of highway electromechanical engineering power supply and distribution technology.
文摘The design process of the built environment relies on the collaborative effort of all parties involved in the project.During the design phase,owners,end users,and their representatives are expected to make the most critical design and budgetary decisions-shaping the essential traits of the project,hence emerge the need and necessity to create and integrate mechanisms to support the decision-making process.Design decisions should not be based on assumptions,past experiences,or imagination.An example of the numerous problems that are a result of uninformed design decisions is“change orders”,known as the deviation from the original scope of work,which leads to an increase of the overall cost,and changes to the construction schedule of the project.The long-term aim of this inquiry is to understand the user’s behavior,and establish evidence-based control measures,which are actions and processes that can be implemented in practice to decrease the volume and frequency of the occurrence of change orders.The current study developed a foundation for further examination by proposing potential control measures,and testing their efficiency,such as integrating Virtual Reality(VR).The specific aim was to examine the effect of different visualization methods(i.e.,VR vs.construction drawings)on,(1)how well the subjects understand the information presented about the future/planned environment;(2)the subjects’perceived confidence in what the future environment will look like;(3)the likelihood of changing the built environment;(4)design review time;and(5)accuracy in reviewing and understanding the design.
基金funded by National Key R&D Program of China(No.2021YFB3401200)the National Natural Science Foundation of China(No.51875308)the Beijing Nature Sciences Fund-Haidian Originality Cooperation Project(L212002).
文摘Numerical simulation is the most powerful computational and analysis tool for a large variety of engineering and physical problems.For a complex problem relating to multi-field,multi-process and multi-scale,different computing tools have to be developed so as to solve particular fields at different scales and for different processes.Therefore,the integration of different types of software is inevitable.However,it is difficult to perform the transfer of the meshes and simulated results among software packages because of the lack of shared data formats or encrypted data formats.An image processing based method for three-dimensional model reconstruction for numerical simulation was proposed,which presents a solution to the integration problem by a series of slice or projection images obtained by the post-processing modules of the numerical simulation software.By means of mapping image pixels to meshes of either finite difference or finite element models,the geometry contour can be extracted to export the stereolithography model.The values of results,represented by color,can be deduced and assigned to the meshes.All the models with data can be directly or indirectly integrated into other software as a continued or new numerical simulation.The three-dimensional reconstruction method has been validated in numerical simulation of castings and case studies were provided in this study.
文摘Objective To study how to improve and perfect the information platform and processing mechanism of drug shortages in China.Methods By searching the relevant policies from official websites of FDA,European Medicines Agency(EMA),Health Canada(HC)and National Health Commission,the good experience of the United States,the European Union and Canada in the construction of information platform and processing mechanism of drug shortages was summarized for reference in China.Results and Conclusion China has initially established the processing mechanism of drug shortages,but the platform construction should be improved,and the information disclosure of drug shortages varies from province to province.We should improve the information platform of drug shortages,strengthen the disclosure and communication of information,enrich the processing tools and measures after the drug shortages occurs,and strengthen the cooperation with relevant associations and other non-governmental departments.
文摘In order to clarify the direction and way of construction enterprise culture,the method of construction enterprise culture based on quality function deployment(QFD)theory is put forward.Firstly,the paper analyzes the QFD theory and the forming process of construction enterprise culture and considers that the two have strong adaptability in the aspects of basic characteristics,implementation process,and logical relationship.Secondly,based on QFD,the basic framework of construction enterprise culture is established,which is divided into three stages:cultural planning,process planning,and implementation planning.Finally,the paper expounds on each link of the cultural planning matrix in detail.
基金supported in part by the Natural Sciences Engineering Research Council of Canada (NSERC)。
文摘This survey paper provides a review and perspective on intermediate and advanced reinforcement learning(RL)techniques in process industries. It offers a holistic approach by covering all levels of the process control hierarchy. The survey paper presents a comprehensive overview of RL algorithms,including fundamental concepts like Markov decision processes and different approaches to RL, such as value-based, policy-based, and actor-critic methods, while also discussing the relationship between classical control and RL. It further reviews the wide-ranging applications of RL in process industries, such as soft sensors, low-level control, high-level control, distributed process control, fault detection and fault tolerant control, optimization,planning, scheduling, and supply chain. The survey paper discusses the limitations and advantages, trends and new applications, and opportunities and future prospects for RL in process industries. Moreover, it highlights the need for a holistic approach in complex systems due to the growing importance of digitalization in the process industries.
基金partially supported by the National Natural Science Foundation of China(11871244)the Fundamental Research Funds for the Central Universities,JLU。
文摘We study the Nadaraya-Watson estimators for the drift function of two-sided reflected stochastic differential equations.The estimates,based on either the continuously observed process or the discretely observed process,are considered.Under certain conditions,we prove the strong consistency and the asymptotic normality of the two estimators.Our method is also suitable for one-sided reflected stochastic differential equations.Simulation results demonstrate that the performance of our estimator is superior to that of the estimator proposed by Cholaquidis et al.(Stat Sin,2021,31:29-51).Several real data sets of the currency exchange rate are used to illustrate our proposed methodology.
基金the National Natural Science Foundation of China(62003298,62163036)the Major Project of Science and Technology of Yunnan Province(202202AD080005,202202AH080009)the Yunnan University Professional Degree Graduate Practice Innovation Fund Project(ZC-22222770)。
文摘Oscillation detection has been a hot research topic in industries due to the high incidence of oscillation loops and their negative impact on plant profitability.Although numerous automatic detection techniques have been proposed,most of them can only address part of the practical difficulties.An oscillation is heuristically defined as a visually apparent periodic variation.However,manual visual inspection is labor-intensive and prone to missed detection.Convolutional neural networks(CNNs),inspired by animal visual systems,have been raised with powerful feature extraction capabilities.In this work,an exploration of the typical CNN models for visual oscillation detection is performed.Specifically,we tested MobileNet-V1,ShuffleNet-V2,Efficient Net-B0,and GhostNet models,and found that such a visual framework is well-suited for oscillation detection.The feasibility and validity of this framework are verified utilizing extensive numerical and industrial cases.Compared with state-of-theart oscillation detectors,the suggested framework is more straightforward and more robust to noise and mean-nonstationarity.In addition,this framework generalizes well and is capable of handling features that are not present in the training data,such as multiple oscillations and outliers.
