It is well known that there exists a tight connection between nonmonotonic reasoning and conditional implication. Many researchers have investigated it from various angles. Among th em, C.Boutilier and P.Lamarre hav...It is well known that there exists a tight connection between nonmonotonic reasoning and conditional implication. Many researchers have investigated it from various angles. Among th em, C.Boutilier and P.Lamarre have shown that some conditional implication may b e regarded as the homology of different nonmonotonic consequence relations. In t his paper, based on the plausibility space introduced by Friedman and Halpern, w e characterize the condition logic in which conditional implication is nonmonoto nic, and this result characterizes the conditional implication which may be rega rded as the corresponding object in Meta language for nonmonotonic inference rel ations.展开更多
BACKGROUND: Presently, over 40 kinds of dural grafts have been successively used in clinic. Among them, lyophilized human dura mater with good histocompatibility and less complications is applied most widely. But the...BACKGROUND: Presently, over 40 kinds of dural grafts have been successively used in clinic. Among them, lyophilized human dura mater with good histocompatibility and less complications is applied most widely. But there are a few reports on cases of infected spongiform encephalopathy following application of lyodura. More ideal repair materials deserve to be further investigated. OBJECTIVE: To investigate the efficiency and safety of biological dural graft made by meninges from porkers to repair meningeal injury. DESIGN: A self-control observation. SETTING: Wuhan General Hospital of Guangzhou Military Area Command of Chinese PLA. MATERIALS: Sixteen New Zealand Rabbits, of either gender, weighing from 2 to 3 kg, of clean grade Ⅱ, with the age of 0.5 - 1 year, were involved in this experiment. The involved rabbits were provided by the Animal Experimental Center of the First Military Medical University of Chinese PLA. Biological surgical patch (dural graft) was developed by Guangdong Guanhao Biotechnological Co.,Ltd. It was processed by using meninges from porkers by tissue engineering technology. METHODS: This experiment was carried out in the Experimental Center of the 157 Hospital of Chinese PLA between December 2003 and June 2004. ①The experimental rabbits were anesthetized. Dura mater was exposed from two sides ofpostmedial line of coronal suture. A rectangular dura mater about 8 mm ×8 mm in size was cut off. Then a biological surgical patch (dural graft) was sheared into insert with 8 mm diameter and sutured. The left dura mater was untouched and used as control. Scalp was sutured, and postoperative wound healing and recovery were observed. ②The anesthetized rabbits were sacrificed at postoperative 3, 14, 30 and 90 days, 4 rabbits once. The whole head was cut off, and its scalp was removed. Afterwards, the head was fixed by formalin. Tissues in operative site were obtained, performed routine paraffin embedding, sliced and conducted HE staining, finally, the sections were observed. White blood cells in venous blood were counted before operation and execution, separately. The obtained data were statistically analyzed. MAIN OUTCOME MEASURES: ①Wound healing and recovery following implantation of dural graft. ②The amount of white blood cells in venous blood from rabbits at each time point before operation and before execution. ③Histological examination results of operative site. RESULTS: Sixteen experimental rabbits were involved in the final analysis. ①The experimental rabbits of each group had no local infection, effusion and abnormal appearance. They had good wound healing and were normal to access to food. ②There were no significant differences in amount of white blood cells in venous blood from experimental rabbits between at each time point after modeling and before operation (P 〉 0.05). ③Pathological observation of operative site : At postoperative 3 days, local acute inflammation repair reaction appeared; At postoperative 2 weeks, chronic inflammatory reaction appeared, endodermis in artificial dural graft formed, and artificial dural graft and host dura mater healed; In postoperative 1 month, wound began to chronically recover; In postoperative 3 months, host blood capillary began to form in artificial dural graft based on chronic repair. In all the control sides, fibroplasia was found, and a few neutrophils were found at postoperative 2 weeks. CONCLUSION: Biological surgical patch has high stability and good histocompatibility. It can provide dural epithelial epithelium, effectively prevent against the conglutination of scalp tissue and brain tissue, and avoid the leakage ofcerebrospinal fluid.展开更多
The surface wave generated by flow around a ship hull moving near free surface of water is simulated numerically in this study. The three-dimensional implicit finite volume method (FVM) is applied to solve Reynolds ...The surface wave generated by flow around a ship hull moving near free surface of water is simulated numerically in this study. The three-dimensional implicit finite volume method (FVM) is applied to solve Reynolds averaged Navier-Stokes (RANS) equation. The realizable k-e turbulence model has been implemented to capture turbulent flow around the ship hull in the free surface zone. The volume of fluid (VOF) method coupled with the Stokes wave theory has been used to determine the free surface effect of water. By using is a six degrees of freedom model, the ship hull's movement is numerically solved with the Stokes wave together. Under the action of Stokes waves on the sea, the interface between the air and water waves at the same regular pattem and so does the pressure and the vertical velocity. The ship hull moves in the same way as the wave. The amplitude of the ship hull's heave is less than the wave height because of the viscosity damping. This method could provide an important reference for the study of ships' movement, wave and hydrodynamics.展开更多
The relation between the HRM and the firm performance is analyzed statistically by many researchers in the literature. However, there are very few nonlinear approaches in literature for finding the relation between Hu...The relation between the HRM and the firm performance is analyzed statistically by many researchers in the literature. However, there are very few nonlinear approaches in literature for finding the relation between Human Resource Management (FIRM) and firm performance. This paper exposes the relationship between human resource management and organizational performance through the use of nonlinear modeling technique. The modeling is proposed based on Radial Basis Function (RBF) which is nonlinear modeling technique in literature. The relation between 12 input and 9 output parameters is investigated in this research that is collected between 54 companies in Turkey which indicated that the relationship between organizational management performance and relationship management can be modelled through nonlinearly.展开更多
This work presents the feasibility study regarding the realization of hail sensing probes for remote sensing and study of hail. The probes are designed as artificial hailstones in order to study both the physical prop...This work presents the feasibility study regarding the realization of hail sensing probes for remote sensing and study of hail. The probes are designed as artificial hailstones in order to study both the physical properties of the portion of atmosphere where the formation of hail occurs and the modification of atmospheric conditions while the hailstones are falling to the ground. The basic idea is to realize sensors with a similar fluid-dynamic behavior with respect to hailstones;the density, the weight and the size of the probes are determined. Consequently, the specification of the electronic boards, sensors, and material to realize the probes are studied and presented. The hail sensing probes can be dropped by a plane, or potentially a UAV (Unmanned Aircraft Vehicle), which fly above and through the clouds where the hail formation occurs. During their falling to the ground, the sensors installed on the probe measure directly different parameters such as humidity, temperature, pressure, acceleration. All data are sent to a receiver located on the ground. The study of the sampling frequency of each sensor is presented, together with the analysis of the propagation channel, in order to assure a robust communication link between probes and the ground receiver. The energy balance is also computed. The work demonstrates that a set of this kind of disposable sensors can be realized. They can be used for efficient monitoring operations and studies of hail formation dynamics and conditions, thus increasing the set of instruments for the monitoring and remote sensing of hail.展开更多
The Corona Virus Disease 2019(COVID-19) pandemic has taught us many valuable lessons regarding the importance of our physical and mental health. Even with so many technological advancements, we still lag in developing...The Corona Virus Disease 2019(COVID-19) pandemic has taught us many valuable lessons regarding the importance of our physical and mental health. Even with so many technological advancements, we still lag in developing a system that can fully digitalize the medical data of each individual and make it readily accessible for both the patient and health worker at any point in time. Moreover, there are also no ways for the government to identify the legitimacy of a particular clinic. This study merges modern technology with traditional approaches,thereby highlighting a scenario where artificial intelligence(AI) merges with traditional Chinese medicine(TCM), proposing a way to advance the conventional approaches. The main objective of our research is to provide a one-stop platform for the government, doctors,nurses, and patients to access their data effortlessly. The proposed portal will also check the doctors’ authenticity. Data is one of the most critical assets of an organization, so a breach of data can risk users’ lives. Data security is of primary importance and must be prioritized. The proposed methodology is based on cloud computing technology which assures the security of the data and avoids any kind of breach. The study also accounts for the difficulties encountered in creating such an infrastructure in the cloud and overcomes the hurdles faced during the project, keeping enough room for possible future innovations. To summarize, this study focuses on the digitalization of medical data and suggests some possible ways to achieve it. Moreover, it also focuses on some related aspects like security and potential digitalization difficulties.展开更多
According to the sampling statistics there are over 7 millions limb disabled persons in China from several times of those in the world. For the benefit to the amputees, thousands varies kinds of commencial Products of...According to the sampling statistics there are over 7 millions limb disabled persons in China from several times of those in the world. For the benefit to the amputees, thousands varies kinds of commencial Products of artificial hands, by scientific promotion have ben developed in the recent half century. Among those products the EMG controlling artificial upper limb brings the hope to the amputees. The later are now used widely form the earlest one in 1948.In 1978, Shanghai Jiao Tong University began to study and develop the EMG controlling artificial band mounted to amputes over thousand disabled during a couple of recent decades.The risidual muscles of an amputee are the signal source of the artificial hand controlled by EMG. The evoked EMG which can transmit the brain moving information is one of the bioelectricities from human body. The EMG signal, accumulated at skin surface with surface electrodes, passing through filtering and amplifying circuits controls the movement-this is the main principle of EMG controlling artificial hand.But, owing to the weakness of EMG (μv) and a group of muscles information plus the strong turbulence of electric field (v), the integrated EMG can’t completely reflect the brain moving act and will influence the accuracy of EMG-hand, especially those of the multi-multi-degree of freedom.In 1978, only 57% of the controlling aaccuracy of artificial hand with 3-degree of freedom could be reached by the Herbert’s research. In 80’s, the controlling accuracy raised up to 72% by Denning’s new method. Up to now, the accuracy is still not ideal, eventhrogh the Hi-tech of using pattern-recognitionand artincial neuro-net work. The electronic artificial hand will be considered successful and practical only with the moving accuracy more than 95%.Some research by using implant electrode for detecting the neuro-information or EEG controllingmethod met also dimculties for raising the accuracy of artificial hand.For breaking througll the threshold of accuracy limit, the EMG method as mentioned above must bechanged entirely, A newest creative research work on the electronic artificial hand controlled by a "regenerated finger" made by transplanting a toe to the stump is developing in Shanghai Jiao TongUniversity, which is without precedent in the world.The first experimental amputee using "regenerated finger’ to control an electronic artificial forearm with 3-degree of freedom reaches 100% accuracy of movements (i.e. no error within 100 tests). It has been proved that the use of a "regenerated finger" as a controlling signal command makes it possible to use the electronic artificeal hand with multi-degree of freedom without error Thecombining medical science with engineering in the area of designing an electronic artifical upper limb.Acknowledgement: The authors extend their hearty thanks to the famous academician Dr.Chen Zhongwei (Zhong-Sen Hospital) for their creative effort and successful micro-surgical operation for transplanting toe to stump of an amputee, also to the China Science Foundation for supporting. us the fund to develop this research.展开更多
Analytical models prepared from field drawings do not generally provide results that match with experimental results.The error may be due to uncertainties in the property of materials,size of members and errors in the...Analytical models prepared from field drawings do not generally provide results that match with experimental results.The error may be due to uncertainties in the property of materials,size of members and errors in the modelling process.It is important to improve analytical models using experimentally obtained data.For the past several years,data obtained from ambient vibration testing have been successfully used in many cases to update and match dynamic behaviors of analytical models with real structures.This paper presents a comparison between artificial neural network(ANN) and eigensensitivity based model updating of an existing multi-story building.A simple spring-mass analytical model,developed from the structural drawings of the building,is considered and the corresponding spring stiffness and lumped mass of all floors are chosen as updating parameters.The advantages and disadvantages of these updating methods are discussed.The advantage is that both methods ensure a physically meaningful model which canbe further employed in determining structural response and health monitoring.展开更多
Concrete is widely used in various large construction projects owing to its high durability,compressive strength,and plasticity.However,the tensile strength of concrete is low,and concrete cracks easily.Changes in the...Concrete is widely used in various large construction projects owing to its high durability,compressive strength,and plasticity.However,the tensile strength of concrete is low,and concrete cracks easily.Changes in the concrete structure will result in changes in parameters such as the frequency mode and curvature mode,which allows one to effectively locate and evaluate structural damages.In this study,the characteristics of the curvature modes in concrete structures are analyzed and a method to obtain the curvature modes based on the strain and displacement modes is proposed.Subsequently,various indices for the damage diagnosis of concrete structures based on the curvature mode are introduced.A damage assessment method for concrete structures is established using an artificial bee colony backpropagation neural network algorithm.The proposed damage assessment method for dam concrete structures comprises various modal parameters,such as curvature and frequency.The feasibility and accuracy of the model are evaluated based on a case study of a concrete gravity dam.The results show that the damage assessment model can accurately evaluate the damage degree of concrete structures with a maximum error of less than 2%,which is within the required accuracy range of damage identification and assessment for most concrete structures.展开更多
Artificial intelligence(AI)is an important driving force in the new round of scientific and technological revolution and industrial transformation,China must grasp the opportunity to its development.Basic researcher...Artificial intelligence(AI)is an important driving force in the new round of scientific and technological revolution and industrial transformation,China must grasp the opportunity to its development.Basic researcher's ability was the inexhaustible driving force to promote the long-term development of AI.The paper focused on 2763 AI researchers who engaged in basic research.The paper analyzed the differences in city distribution and research direction of this group in China,and further explored the influence of different cities on research output,as well as the interactive influence between city and institution on their research output.The study found that there was a prominent phenomenon of aggregation of AI basic researchers in China,and their research fields were mainly focused on machine learning,computer vision,patterm recognition and data mining.The economic level of the city had a positive impact on the paper output and the project undertaken by researchers.The development vitality of the city had a positive impact on the researchers'patent output.The high-quality platform of the institution would make up for the disadvantages caused by the city's lower economy.Therefore,in China,it was necessary to determine the development orientation of cities at different levels so that they could play different roles in the industrial development.Economically underdeveloped cities should allocate resources rationally,enhance the deep cooperation between non-first-class institutions and local AI enterprises,and provide a good scientific research ecological environment for the growth of local AI basic researchers.展开更多
文摘It is well known that there exists a tight connection between nonmonotonic reasoning and conditional implication. Many researchers have investigated it from various angles. Among th em, C.Boutilier and P.Lamarre have shown that some conditional implication may b e regarded as the homology of different nonmonotonic consequence relations. In t his paper, based on the plausibility space introduced by Friedman and Halpern, w e characterize the condition logic in which conditional implication is nonmonoto nic, and this result characterizes the conditional implication which may be rega rded as the corresponding object in Meta language for nonmonotonic inference rel ations.
文摘BACKGROUND: Presently, over 40 kinds of dural grafts have been successively used in clinic. Among them, lyophilized human dura mater with good histocompatibility and less complications is applied most widely. But there are a few reports on cases of infected spongiform encephalopathy following application of lyodura. More ideal repair materials deserve to be further investigated. OBJECTIVE: To investigate the efficiency and safety of biological dural graft made by meninges from porkers to repair meningeal injury. DESIGN: A self-control observation. SETTING: Wuhan General Hospital of Guangzhou Military Area Command of Chinese PLA. MATERIALS: Sixteen New Zealand Rabbits, of either gender, weighing from 2 to 3 kg, of clean grade Ⅱ, with the age of 0.5 - 1 year, were involved in this experiment. The involved rabbits were provided by the Animal Experimental Center of the First Military Medical University of Chinese PLA. Biological surgical patch (dural graft) was developed by Guangdong Guanhao Biotechnological Co.,Ltd. It was processed by using meninges from porkers by tissue engineering technology. METHODS: This experiment was carried out in the Experimental Center of the 157 Hospital of Chinese PLA between December 2003 and June 2004. ①The experimental rabbits were anesthetized. Dura mater was exposed from two sides ofpostmedial line of coronal suture. A rectangular dura mater about 8 mm ×8 mm in size was cut off. Then a biological surgical patch (dural graft) was sheared into insert with 8 mm diameter and sutured. The left dura mater was untouched and used as control. Scalp was sutured, and postoperative wound healing and recovery were observed. ②The anesthetized rabbits were sacrificed at postoperative 3, 14, 30 and 90 days, 4 rabbits once. The whole head was cut off, and its scalp was removed. Afterwards, the head was fixed by formalin. Tissues in operative site were obtained, performed routine paraffin embedding, sliced and conducted HE staining, finally, the sections were observed. White blood cells in venous blood were counted before operation and execution, separately. The obtained data were statistically analyzed. MAIN OUTCOME MEASURES: ①Wound healing and recovery following implantation of dural graft. ②The amount of white blood cells in venous blood from rabbits at each time point before operation and before execution. ③Histological examination results of operative site. RESULTS: Sixteen experimental rabbits were involved in the final analysis. ①The experimental rabbits of each group had no local infection, effusion and abnormal appearance. They had good wound healing and were normal to access to food. ②There were no significant differences in amount of white blood cells in venous blood from experimental rabbits between at each time point after modeling and before operation (P 〉 0.05). ③Pathological observation of operative site : At postoperative 3 days, local acute inflammation repair reaction appeared; At postoperative 2 weeks, chronic inflammatory reaction appeared, endodermis in artificial dural graft formed, and artificial dural graft and host dura mater healed; In postoperative 1 month, wound began to chronically recover; In postoperative 3 months, host blood capillary began to form in artificial dural graft based on chronic repair. In all the control sides, fibroplasia was found, and a few neutrophils were found at postoperative 2 weeks. CONCLUSION: Biological surgical patch has high stability and good histocompatibility. It can provide dural epithelial epithelium, effectively prevent against the conglutination of scalp tissue and brain tissue, and avoid the leakage ofcerebrospinal fluid.
基金Foundation item: Supported by National Natural Science Foundation of China (51409031), Fundamental Research Funds for the Central Universities (3132015203) and China Postdoctoral Science Foundation (2014M561216).
文摘The surface wave generated by flow around a ship hull moving near free surface of water is simulated numerically in this study. The three-dimensional implicit finite volume method (FVM) is applied to solve Reynolds averaged Navier-Stokes (RANS) equation. The realizable k-e turbulence model has been implemented to capture turbulent flow around the ship hull in the free surface zone. The volume of fluid (VOF) method coupled with the Stokes wave theory has been used to determine the free surface effect of water. By using is a six degrees of freedom model, the ship hull's movement is numerically solved with the Stokes wave together. Under the action of Stokes waves on the sea, the interface between the air and water waves at the same regular pattem and so does the pressure and the vertical velocity. The ship hull moves in the same way as the wave. The amplitude of the ship hull's heave is less than the wave height because of the viscosity damping. This method could provide an important reference for the study of ships' movement, wave and hydrodynamics.
文摘The relation between the HRM and the firm performance is analyzed statistically by many researchers in the literature. However, there are very few nonlinear approaches in literature for finding the relation between Human Resource Management (FIRM) and firm performance. This paper exposes the relationship between human resource management and organizational performance through the use of nonlinear modeling technique. The modeling is proposed based on Radial Basis Function (RBF) which is nonlinear modeling technique in literature. The relation between 12 input and 9 output parameters is investigated in this research that is collected between 54 companies in Turkey which indicated that the relationship between organizational management performance and relationship management can be modelled through nonlinearly.
文摘This work presents the feasibility study regarding the realization of hail sensing probes for remote sensing and study of hail. The probes are designed as artificial hailstones in order to study both the physical properties of the portion of atmosphere where the formation of hail occurs and the modification of atmospheric conditions while the hailstones are falling to the ground. The basic idea is to realize sensors with a similar fluid-dynamic behavior with respect to hailstones;the density, the weight and the size of the probes are determined. Consequently, the specification of the electronic boards, sensors, and material to realize the probes are studied and presented. The hail sensing probes can be dropped by a plane, or potentially a UAV (Unmanned Aircraft Vehicle), which fly above and through the clouds where the hail formation occurs. During their falling to the ground, the sensors installed on the probe measure directly different parameters such as humidity, temperature, pressure, acceleration. All data are sent to a receiver located on the ground. The study of the sampling frequency of each sensor is presented, together with the analysis of the propagation channel, in order to assure a robust communication link between probes and the ground receiver. The energy balance is also computed. The work demonstrates that a set of this kind of disposable sensors can be realized. They can be used for efficient monitoring operations and studies of hail formation dynamics and conditions, thus increasing the set of instruments for the monitoring and remote sensing of hail.
文摘The Corona Virus Disease 2019(COVID-19) pandemic has taught us many valuable lessons regarding the importance of our physical and mental health. Even with so many technological advancements, we still lag in developing a system that can fully digitalize the medical data of each individual and make it readily accessible for both the patient and health worker at any point in time. Moreover, there are also no ways for the government to identify the legitimacy of a particular clinic. This study merges modern technology with traditional approaches,thereby highlighting a scenario where artificial intelligence(AI) merges with traditional Chinese medicine(TCM), proposing a way to advance the conventional approaches. The main objective of our research is to provide a one-stop platform for the government, doctors,nurses, and patients to access their data effortlessly. The proposed portal will also check the doctors’ authenticity. Data is one of the most critical assets of an organization, so a breach of data can risk users’ lives. Data security is of primary importance and must be prioritized. The proposed methodology is based on cloud computing technology which assures the security of the data and avoids any kind of breach. The study also accounts for the difficulties encountered in creating such an infrastructure in the cloud and overcomes the hurdles faced during the project, keeping enough room for possible future innovations. To summarize, this study focuses on the digitalization of medical data and suggests some possible ways to achieve it. Moreover, it also focuses on some related aspects like security and potential digitalization difficulties.
文摘According to the sampling statistics there are over 7 millions limb disabled persons in China from several times of those in the world. For the benefit to the amputees, thousands varies kinds of commencial Products of artificial hands, by scientific promotion have ben developed in the recent half century. Among those products the EMG controlling artificial upper limb brings the hope to the amputees. The later are now used widely form the earlest one in 1948.In 1978, Shanghai Jiao Tong University began to study and develop the EMG controlling artificial band mounted to amputes over thousand disabled during a couple of recent decades.The risidual muscles of an amputee are the signal source of the artificial hand controlled by EMG. The evoked EMG which can transmit the brain moving information is one of the bioelectricities from human body. The EMG signal, accumulated at skin surface with surface electrodes, passing through filtering and amplifying circuits controls the movement-this is the main principle of EMG controlling artificial hand.But, owing to the weakness of EMG (μv) and a group of muscles information plus the strong turbulence of electric field (v), the integrated EMG can’t completely reflect the brain moving act and will influence the accuracy of EMG-hand, especially those of the multi-multi-degree of freedom.In 1978, only 57% of the controlling aaccuracy of artificial hand with 3-degree of freedom could be reached by the Herbert’s research. In 80’s, the controlling accuracy raised up to 72% by Denning’s new method. Up to now, the accuracy is still not ideal, eventhrogh the Hi-tech of using pattern-recognitionand artincial neuro-net work. The electronic artificial hand will be considered successful and practical only with the moving accuracy more than 95%.Some research by using implant electrode for detecting the neuro-information or EEG controllingmethod met also dimculties for raising the accuracy of artificial hand.For breaking througll the threshold of accuracy limit, the EMG method as mentioned above must bechanged entirely, A newest creative research work on the electronic artificial hand controlled by a "regenerated finger" made by transplanting a toe to the stump is developing in Shanghai Jiao TongUniversity, which is without precedent in the world.The first experimental amputee using "regenerated finger’ to control an electronic artificial forearm with 3-degree of freedom reaches 100% accuracy of movements (i.e. no error within 100 tests). It has been proved that the use of a "regenerated finger" as a controlling signal command makes it possible to use the electronic artificeal hand with multi-degree of freedom without error Thecombining medical science with engineering in the area of designing an electronic artifical upper limb.Acknowledgement: The authors extend their hearty thanks to the famous academician Dr.Chen Zhongwei (Zhong-Sen Hospital) for their creative effort and successful micro-surgical operation for transplanting toe to stump of an amputee, also to the China Science Foundation for supporting. us the fund to develop this research.
文摘Analytical models prepared from field drawings do not generally provide results that match with experimental results.The error may be due to uncertainties in the property of materials,size of members and errors in the modelling process.It is important to improve analytical models using experimentally obtained data.For the past several years,data obtained from ambient vibration testing have been successfully used in many cases to update and match dynamic behaviors of analytical models with real structures.This paper presents a comparison between artificial neural network(ANN) and eigensensitivity based model updating of an existing multi-story building.A simple spring-mass analytical model,developed from the structural drawings of the building,is considered and the corresponding spring stiffness and lumped mass of all floors are chosen as updating parameters.The advantages and disadvantages of these updating methods are discussed.The advantage is that both methods ensure a physically meaningful model which canbe further employed in determining structural response and health monitoring.
基金the National Key R&D Program of China(No.2022YFC3005401)the National Natural Science Foundation of China(Grant No.52309152)+2 种基金the Fundamental Research Funds for the Central Universities(B230201013)the Natural Science Foundation of Jiangsu Province(BK20220978)China Postdoctoral Science Foundation(2022M720998).
文摘Concrete is widely used in various large construction projects owing to its high durability,compressive strength,and plasticity.However,the tensile strength of concrete is low,and concrete cracks easily.Changes in the concrete structure will result in changes in parameters such as the frequency mode and curvature mode,which allows one to effectively locate and evaluate structural damages.In this study,the characteristics of the curvature modes in concrete structures are analyzed and a method to obtain the curvature modes based on the strain and displacement modes is proposed.Subsequently,various indices for the damage diagnosis of concrete structures based on the curvature mode are introduced.A damage assessment method for concrete structures is established using an artificial bee colony backpropagation neural network algorithm.The proposed damage assessment method for dam concrete structures comprises various modal parameters,such as curvature and frequency.The feasibility and accuracy of the model are evaluated based on a case study of a concrete gravity dam.The results show that the damage assessment model can accurately evaluate the damage degree of concrete structures with a maximum error of less than 2%,which is within the required accuracy range of damage identification and assessment for most concrete structures.
基金"Research on Peer Review Method Model in Big Data Environment",National Social Science Foundation of China(19BTQ082)"Research on the Discovery of Disruptive Technology Research Teams",General Program of Innovation Research Fund of Institute of Scientific and Technical Information of China(MS2021-08).
文摘Artificial intelligence(AI)is an important driving force in the new round of scientific and technological revolution and industrial transformation,China must grasp the opportunity to its development.Basic researcher's ability was the inexhaustible driving force to promote the long-term development of AI.The paper focused on 2763 AI researchers who engaged in basic research.The paper analyzed the differences in city distribution and research direction of this group in China,and further explored the influence of different cities on research output,as well as the interactive influence between city and institution on their research output.The study found that there was a prominent phenomenon of aggregation of AI basic researchers in China,and their research fields were mainly focused on machine learning,computer vision,patterm recognition and data mining.The economic level of the city had a positive impact on the paper output and the project undertaken by researchers.The development vitality of the city had a positive impact on the researchers'patent output.The high-quality platform of the institution would make up for the disadvantages caused by the city's lower economy.Therefore,in China,it was necessary to determine the development orientation of cities at different levels so that they could play different roles in the industrial development.Economically underdeveloped cities should allocate resources rationally,enhance the deep cooperation between non-first-class institutions and local AI enterprises,and provide a good scientific research ecological environment for the growth of local AI basic researchers.