In order to investigate the benefit of multiple-input multiple-output(MIMO) technique applying to the high altitude platform(HAP), a 2×2 MIMO statistical model, which can accurately describe the channel between H...In order to investigate the benefit of multiple-input multiple-output(MIMO) technique applying to the high altitude platform(HAP), a 2×2 MIMO statistical model, which can accurately describe the channel between HAP and high-speed train, is presented. And dual polarization diversity is particularly considered. Based on first-order three-state Markov chain, the single-input single-output(SISO) channel, a subset of the MIMO channel is first established. The ray tracing approach applied to the digital relief model(DRM) which covers the railway between Xi'an and Zhengzhou is used to obtain the state probability vector and matrix of the state transition probability. The proposed model considers both Doppler shift and temporal correlation, and the polarization correlation and spatial correlation statistical properties of large-scale fading and smallscale fading are analyzed. Moreover, useful numerical results on the MIMO HAP channel outage capacity are provided based on which, significant capacity gains with respect to the conventional SISO case are illustrated. Such statistical channel model can be applied to the future wireless communication system between HAP and high-speed train.展开更多
Energy-efficient retrofitting(EER)of existing buildings has significant potential for addressing energy and environmental issues.However,the traditional market trading model is characterized by an inefficient dissemin...Energy-efficient retrofitting(EER)of existing buildings has significant potential for addressing energy and environmental issues.However,the traditional market trading model is characterized by an inefficient dissemination of critical information,which leads to insufficient incentives for market participants to trade.To solve these problems,this study constructs a three-party evolutionary game model with energy saving service companies(ESCO),homeowners,and trading information platforms as the main players,analyzes the interaction and evolution of the three parties'strategies under the scenario of government rewards and penalties,and explores the effects of the three parties'initial willingness and changes of model parameters on the evolution of their strategies.There are some findings as follows:first,the positive transactions of homeowners and ESCOs have less influence on the platform side;second,compared with homeowners,the government penalties have more obvious constraints on the platform side and ESCOs;third,government subsidies and EER revenues are the important factors influencing the speed of the evolution of three-party strategies,fourth,platform service compensation,the factors governing cost and benefit sharing are pivotal in determining the alignment of strategic choices among the three parties involved.Based on the research conclusions.This study offers theoretical guidance for the advancement of platform-based market transactions for EER.展开更多
A ground-based hardware-in-the-loop （HIL） simulation system with hydraulically driven Stewart platform for spacecraft docking simulation is presented. The system is used for simulating docking process of the on-orbi...A ground-based hardware-in-the-loop （HIL） simulation system with hydraulically driven Stewart platform for spacecraft docking simulation is presented. The system is used for simulating docking process of the on-orbit spacecraft. Principle and structure of the six-degree-of-freedom simulation system are introduced. The docking process dynamic of the vehicles is modeled. Experiment results and mathematical simulation data are compared to validating the simulation system. The comparisons of the results prove that the simulation system proposed can effectively simulate the on-orbit docking process of the spacecraft.展开更多
Model driven architecture(MDA) is an evolutionary step in software development.Model transformation forms a key part of MDA.The transformation from computation independent model(CIM) to platform independent model(PIM)...Model driven architecture(MDA) is an evolutionary step in software development.Model transformation forms a key part of MDA.The transformation from computation independent model(CIM) to platform independent model(PIM) is the first step of the transformation.This paper proposes an approach for this transformation with pattern.In this approach, we take advantage of"reuse"from various standpoints.Feature model is used to describe the requirement of the application.This can help us bring"reuse"into effect at requirement level.Moreover we use pattern to transform CIM to PIM.This can help us bring"reuse"into effect at development level.Meanwhile, pattern was divided into four hierarchies.Different hierarchies of pattern are used to help us utilize reuse at different phase of development.From another standpoint, feature model describes the problem of a domain while pattern describe the problem across domains.This can help us reuse the element in and across domains.Finally, the detailed process of the transformation is given.展开更多
The platform scheduling problem in battlefield is one of the important problems in military operational research.It needs to minimize mission completing time and meanwhile maximize the mission completing accuracy with...The platform scheduling problem in battlefield is one of the important problems in military operational research.It needs to minimize mission completing time and meanwhile maximize the mission completing accuracy with a limited number of platforms.Though the traditional certain models obtain some good results,uncertain model is still needed to be introduced since the battlefield environment is complex and unstable.An uncertain model is prposed for the platform scheduling problem.Related parameters in this model are set to be fuzzy or stochastic.Due to the inherent disadvantage of the solving methods for traditional models,a new method is proposed to solve the uncertain model.Finally,the practicability and availability of the proposed method are demonstrated with a case of joint campaign.展开更多
Planation surface, a surface that is almost flat, is a kind of low-relief landforms. Planation surface is the consequence of the denudation and planation processes under a tectonic stable condition. The quantitative e...Planation surface, a surface that is almost flat, is a kind of low-relief landforms. Planation surface is the consequence of the denudation and planation processes under a tectonic stable condition. The quantitative expression of the characteristics of planation surface plays a key role in reconstructing and describing the evolutionary process of landforms. In this study, Landform Planation Index(LPI), a new terrain derivative, was proposed to quantify the characteristics of planation surface. The LPIs were calculated based on the summit surfaces formed according to the clustering results of peaks. Ten typical areas in the Ordos Platform located in the central part of the Loess Plateau of China are chosen as the test areas for investigating their planation characteristics with the LPI. The experimental results indicate that the LPI can be effectively used to quantify the characteristics of planation surfaces. In addition, the LPI can be further used to depict the patterns of spatial differentiation in the Ordos Platform. Although the present Ordos Platform area is full of the high-density gullies, its planation characteristics is found to be well preserved. Furthermore, the characteristics of the planation surfaces can also reflect the original morphology of the Ordos Platform before the loess dusts deposition process evolved in this area. The statistical results of the LPI show that there is a gradually increasing tendency along with the increasing of slope gradient of summit surface. It indicates that the characteristics of planation surfaces vary among test areas with different landforms. These findings help to deepen the understanding of planation characteristics of the loess landform and its underlying paleotopography. Results of this study can be also served as an important theoretical reference value for revealing the evolutionary process of loess landform.展开更多
Leveraging the Baidu Qianfan model platform,this paper designs and implements a highly efficient and accurate scoring system for subjective questions,focusing primarily on questions in the field of computer network te...Leveraging the Baidu Qianfan model platform,this paper designs and implements a highly efficient and accurate scoring system for subjective questions,focusing primarily on questions in the field of computer network technology.The system enhances the foundational model by utilizing Qianfan’s training tools and integrating advanced techniques,such as supervised fine-tuning.In the data preparation phase,a comprehensive collection of subjective data related to computer network technology is gathered,cleaned,and labeled.During model training and evaluation,optimal hyperparameters and tuning strategies are applied,resulting in a model capable of scoring with high accuracy.Evaluation results demonstrate that the proposed model performs well across multiple dimensions-content,expression,and development scores-yielding results comparable to those of manual scoring.展开更多
In order to achieve an automatic leveling function for work platforms of aerial vehicles with mixed-booms( MAV) in full elevating domain,an auto-leveling mechanism for the platform is proposed based on a control metho...In order to achieve an automatic leveling function for work platforms of aerial vehicles with mixed-booms( MAV) in full elevating domain,an auto-leveling mechanism for the platform is proposed based on a control method of booms-constraint,where mixed-boom structures and elevating characteristics are considered. Three models of constraint strategies include non-constraint model,elevating constraint model and lowering constraint model,which is designed to meet the leveling requirements in full working extent. Through the hydro-mechatronic unified modeling,a virtual prototype model is set up based on the auto-leveling mechanism,and leveling performances of the platform are studied during booms elevating to the maximum working height and extent. Simulation results show that the control method of booms-constraint can realize auto-leveling of the platform under two typical working conditions,meanwhile a leveling deviation appears at the constrained point,but the platform inclination is adjusted in the permissible range. The control method does not only restrict booms' freedom elevating to a certain extent,but also impacts the booms extending to the maximum working range. Experimental results verify that the auto-leveling mechanism based on booms-constraint control is valid and rational,which provides an effective technology approach for development of the platform leveling of MAV.展开更多
Smart logistics is a new direction for the development of the current logistics industry. This paper mainly analyzes and summarizes the main development status of China's smart logistics and related policies. It f...Smart logistics is a new direction for the development of the current logistics industry. This paper mainly analyzes and summarizes the main development status of China's smart logistics and related policies. It finds that China's current investment in innovation and the application of smart systems in the smart logistics industry are gradually increasing, indicating that China's entire logistics system is also in constant transition towards smart direction. However, there is still a certain gap between the related technology application level and the international developed countries, and these problems should be solved in a timely manner. At the same time, this paper also puts forward specific suggestions on relevant issues, hoping to provide certain reference value for the development of China's smart logistics business platform model and innovation mechanism.展开更多
Combat system effectiveness simulation (CSES) is a special type of complex system simulation. Three non-functional requirements (NFRs), i.e. model composability, domain specific modeling, and model evolvability, are g...Combat system effectiveness simulation (CSES) is a special type of complex system simulation. Three non-functional requirements (NFRs), i.e. model composability, domain specific modeling, and model evolvability, are gaining higher priority from CSES users when evaluating different modeling methodologies for CSES. Traditional CSES modeling methodologies are either domain-neutral (lack of domain characteristics consideration and limited support for model composability) or domain-oriented (lack of openness and evolvability) and fall short of the three NFRs. Inspired by the concept of architecture in systems engineering and software engineering fields, we extend it into a concept of model architecture for complex simulation systems, and propose a model architecture-oriented modeling methodology in which the model architecture plays a central role in achieving the three NFRs. Various model-driven engineering (MDE) approaches and technologies, including simulation modeling platform (SMP), unified modeling language (UML), domain specific modeling (DSM), eclipse modeling framework (EMF), graphical modeling framework (GMF), and so forth, are applied where possible in representing the CSES model architecture and its components' behaviors from physical and cognitive domain aspects. A prototype CSES system, called weapon effectiveness simulation system (WESS), and a non-trivial air-combat simulation example are presented to demonstrate the methodology.展开更多
Trusted platform model （TPM） is special-purpose integrated circuits （ICs） built into a variety of platforms to enable strong user authentication and machine attestation-essential to prevent inappropriate access to...Trusted platform model （TPM） is special-purpose integrated circuits （ICs） built into a variety of platforms to enable strong user authentication and machine attestation-essential to prevent inappropriate access to confidential and sensitive information and to protect against compromised networks. Existing TPM products have some limitations. This paper adopts J2810TPM Single Chip cryptogram MCU produced by Jetway Company to construct typical TPM after comparing existing TPM products. Finally, an improved construction approach of TPM based on J2810 is proposed.展开更多
Smart cities initiatives are developing all over the world, due to their support in favouring a better provision of services, in connection with the aim of achieving efficiency in cities management. More and more big ...Smart cities initiatives are developing all over the world, due to their support in favouring a better provision of services, in connection with the aim of achieving efficiency in cities management. More and more big corporations are interested in this topic to develop their businesses, as several issues are linked to these projects, like environment, water management, energy policies, education, culture, and so on. In literature these issues, known as drivers, were also related to sustainability aims which could be reached through the accomplishment of better performances within environment, economy, and society. This study synthesizes all the different drivers identified by scholars and industry players in a model, in order to use it as a framework to depict the linkages among the various smart cities projects. Since transport resulted as one of the most considered drivers in the analyzed contributions, the research questions were delineated to describe its role in the different phases of smart initiatives, and to understand if it could encourage and enable the other drivers＇ development. The multiple case study was chosen as the fittest methodological approach and it was conducted with the selection of three smart cities, one for each of the most cited platform models developed by industry players, which had started transport initiatives at least three years ago： Singapore （IBM）, Amsterdam （Accenture）, and San Francisco （Microsoft）. The analysis of the official documents set up by city departments and by the industry players showed transport as a driving force in smart cities projects which conveys a smart approach to different domains, especially energy savings, environment, and safety. The results also showed smart mobility as a pivot in stimulating investments and citizens＇ participation on different city drivers, especially as it concerns environment and services to both citizens and businesses. Smart transport initiatives, hardware and software infrastructures, technological devices, and people participation to smartization were closely interrelated in smart cities projects and they could be successfully used to achieve sustainability aims for different stakeholders.展开更多
Bistatic/multistatic radar has great potential advantages over its monostatic counterpart. However, the separation of a transmitter and a receiver leads to difficulties in locating the target position accurately and g...Bistatic/multistatic radar has great potential advantages over its monostatic counterpart. However, the separation of a transmitter and a receiver leads to difficulties in locating the target position accurately and guaranteeing space-timefrequency synchronization of the transmitter and the receiver.The error model of space-time-frequency synchronization in a motion platform of bistatic/multistatic radar is studied. The relationship between the space synchronization error and the transmitter platform position, receiver platform position, moving state, and beam pointing error, is analyzed. The effect of space synchronization error on target echo power is studied. The target scattering characteristics are restructured by many separate scattering centers of the target in high frequency regions. Based on the scattering centers model of the radar target, this radar target echo model and the simulation method are discussed. The algorithm of bistatic/multistatic radar target echo accurately reflects the scattering characteristics of the radar target, pulse modulation speciality of radar transmitting signals, and spacetime-frequency synchronization error characteristics between the transmitter station and the receiver station. The simulation of bistatic radar is completed in computer, and the results of the simulation validate the feasibility of the method.展开更多
In this perspective,"CASES"are made for AI in medicine.The CASES mean Confidence,Adaptability,Stability,Explainability,and Security of AI systems.We underline that these CASES can be addressed not only indiv...In this perspective,"CASES"are made for AI in medicine.The CASES mean Confidence,Adaptability,Stability,Explainability,and Security of AI systems.We underline that these CASES can be addressed not only individually but also synergistically on the large model platform and using cutting-edge diffusion-type models.展开更多
Data storage security has become the core of many network security issues.In order to achieve trusted storage and trusted measurement of network community data,this paper proposes a secure storage model based on trust...Data storage security has become the core of many network security issues.In order to achieve trusted storage and trusted measurement of network community data,this paper proposes a secure storage model based on trust extension for existing trusted storage technologies.In the process of document encryption,the key information is encrypted as well as decentralized stored by optimizing the ciphertext inverted index structure and update policy to ensure the security of index information.In the process of user access control mechanism,SAML and XACML are used in combination with role-based access control in order to achieve flexible and efficient authorization and access control.In the process of result query,ontology technology is introduced to better express the user’s query intention and improve the query accuracy.A large number of experiments demonstrate the effectiveness and feasibility of the scheme.展开更多
基金sponsored by National Natural Science Foundation of China (No.91538104,No.91438205)China Postdoctoral Science Foundation (No.2011M500664)
文摘In order to investigate the benefit of multiple-input multiple-output(MIMO) technique applying to the high altitude platform(HAP), a 2×2 MIMO statistical model, which can accurately describe the channel between HAP and high-speed train, is presented. And dual polarization diversity is particularly considered. Based on first-order three-state Markov chain, the single-input single-output(SISO) channel, a subset of the MIMO channel is first established. The ray tracing approach applied to the digital relief model(DRM) which covers the railway between Xi'an and Zhengzhou is used to obtain the state probability vector and matrix of the state transition probability. The proposed model considers both Doppler shift and temporal correlation, and the polarization correlation and spatial correlation statistical properties of large-scale fading and smallscale fading are analyzed. Moreover, useful numerical results on the MIMO HAP channel outage capacity are provided based on which, significant capacity gains with respect to the conventional SISO case are illustrated. Such statistical channel model can be applied to the future wireless communication system between HAP and high-speed train.
基金supported by the National Natural Science Foundation of China(Grant No.71872122)the Late-stage Subsidy Project of Humanities and Social Sciences of the Education Department of China(Grant No.20JHQ095).
文摘Energy-efficient retrofitting(EER)of existing buildings has significant potential for addressing energy and environmental issues.However,the traditional market trading model is characterized by an inefficient dissemination of critical information,which leads to insufficient incentives for market participants to trade.To solve these problems,this study constructs a three-party evolutionary game model with energy saving service companies(ESCO),homeowners,and trading information platforms as the main players,analyzes the interaction and evolution of the three parties'strategies under the scenario of government rewards and penalties,and explores the effects of the three parties'initial willingness and changes of model parameters on the evolution of their strategies.There are some findings as follows:first,the positive transactions of homeowners and ESCOs have less influence on the platform side;second,compared with homeowners,the government penalties have more obvious constraints on the platform side and ESCOs;third,government subsidies and EER revenues are the important factors influencing the speed of the evolution of three-party strategies,fourth,platform service compensation,the factors governing cost and benefit sharing are pivotal in determining the alignment of strategic choices among the three parties involved.Based on the research conclusions.This study offers theoretical guidance for the advancement of platform-based market transactions for EER.
文摘A ground-based hardware-in-the-loop （HIL） simulation system with hydraulically driven Stewart platform for spacecraft docking simulation is presented. The system is used for simulating docking process of the on-orbit spacecraft. Principle and structure of the six-degree-of-freedom simulation system are introduced. The docking process dynamic of the vehicles is modeled. Experiment results and mathematical simulation data are compared to validating the simulation system. The comparisons of the results prove that the simulation system proposed can effectively simulate the on-orbit docking process of the spacecraft.
基金supported by the National Natural Science Foundation of China (Grant No.601730301)the National BasicResearch Program of China (973 Program) (Grant No.2002CB312001)
文摘Model driven architecture(MDA) is an evolutionary step in software development.Model transformation forms a key part of MDA.The transformation from computation independent model(CIM) to platform independent model(PIM) is the first step of the transformation.This paper proposes an approach for this transformation with pattern.In this approach, we take advantage of"reuse"from various standpoints.Feature model is used to describe the requirement of the application.This can help us bring"reuse"into effect at requirement level.Moreover we use pattern to transform CIM to PIM.This can help us bring"reuse"into effect at development level.Meanwhile, pattern was divided into four hierarchies.Different hierarchies of pattern are used to help us utilize reuse at different phase of development.From another standpoint, feature model describes the problem of a domain while pattern describe the problem across domains.This can help us reuse the element in and across domains.Finally, the detailed process of the transformation is given.
基金supported by the National Natural Science Foundation of China(61573017)
文摘The platform scheduling problem in battlefield is one of the important problems in military operational research.It needs to minimize mission completing time and meanwhile maximize the mission completing accuracy with a limited number of platforms.Though the traditional certain models obtain some good results,uncertain model is still needed to be introduced since the battlefield environment is complex and unstable.An uncertain model is prposed for the platform scheduling problem.Related parameters in this model are set to be fuzzy or stochastic.Due to the inherent disadvantage of the solving methods for traditional models,a new method is proposed to solve the uncertain model.Finally,the practicability and availability of the proposed method are demonstrated with a case of joint campaign.
基金Under the auspices of National Natural Science Foundation of China(No.41201464,41471316)Priority Academic Program Development of Jiangsu Higher Education Institutions(No.164320H101)
文摘Planation surface, a surface that is almost flat, is a kind of low-relief landforms. Planation surface is the consequence of the denudation and planation processes under a tectonic stable condition. The quantitative expression of the characteristics of planation surface plays a key role in reconstructing and describing the evolutionary process of landforms. In this study, Landform Planation Index(LPI), a new terrain derivative, was proposed to quantify the characteristics of planation surface. The LPIs were calculated based on the summit surfaces formed according to the clustering results of peaks. Ten typical areas in the Ordos Platform located in the central part of the Loess Plateau of China are chosen as the test areas for investigating their planation characteristics with the LPI. The experimental results indicate that the LPI can be effectively used to quantify the characteristics of planation surfaces. In addition, the LPI can be further used to depict the patterns of spatial differentiation in the Ordos Platform. Although the present Ordos Platform area is full of the high-density gullies, its planation characteristics is found to be well preserved. Furthermore, the characteristics of the planation surfaces can also reflect the original morphology of the Ordos Platform before the loess dusts deposition process evolved in this area. The statistical results of the LPI show that there is a gradually increasing tendency along with the increasing of slope gradient of summit surface. It indicates that the characteristics of planation surfaces vary among test areas with different landforms. These findings help to deepen the understanding of planation characteristics of the loess landform and its underlying paleotopography. Results of this study can be also served as an important theoretical reference value for revealing the evolutionary process of loess landform.
文摘Leveraging the Baidu Qianfan model platform,this paper designs and implements a highly efficient and accurate scoring system for subjective questions,focusing primarily on questions in the field of computer network technology.The system enhances the foundational model by utilizing Qianfan’s training tools and integrating advanced techniques,such as supervised fine-tuning.In the data preparation phase,a comprehensive collection of subjective data related to computer network technology is gathered,cleaned,and labeled.During model training and evaluation,optimal hyperparameters and tuning strategies are applied,resulting in a model capable of scoring with high accuracy.Evaluation results demonstrate that the proposed model performs well across multiple dimensions-content,expression,and development scores-yielding results comparable to those of manual scoring.
基金Supported by the National Natural Science Foundation of China(No.51509006)National Key Technology R&D Program(No.2015BAF07B08)Fundamental Research Funds for the Central Universities of Chang’an University(No.310825161008)
文摘In order to achieve an automatic leveling function for work platforms of aerial vehicles with mixed-booms( MAV) in full elevating domain,an auto-leveling mechanism for the platform is proposed based on a control method of booms-constraint,where mixed-boom structures and elevating characteristics are considered. Three models of constraint strategies include non-constraint model,elevating constraint model and lowering constraint model,which is designed to meet the leveling requirements in full working extent. Through the hydro-mechatronic unified modeling,a virtual prototype model is set up based on the auto-leveling mechanism,and leveling performances of the platform are studied during booms elevating to the maximum working height and extent. Simulation results show that the control method of booms-constraint can realize auto-leveling of the platform under two typical working conditions,meanwhile a leveling deviation appears at the constrained point,but the platform inclination is adjusted in the permissible range. The control method does not only restrict booms' freedom elevating to a certain extent,but also impacts the booms extending to the maximum working range. Experimental results verify that the auto-leveling mechanism based on booms-constraint control is valid and rational,which provides an effective technology approach for development of the platform leveling of MAV.
文摘Smart logistics is a new direction for the development of the current logistics industry. This paper mainly analyzes and summarizes the main development status of China's smart logistics and related policies. It finds that China's current investment in innovation and the application of smart systems in the smart logistics industry are gradually increasing, indicating that China's entire logistics system is also in constant transition towards smart direction. However, there is still a certain gap between the related technology application level and the international developed countries, and these problems should be solved in a timely manner. At the same time, this paper also puts forward specific suggestions on relevant issues, hoping to provide certain reference value for the development of China's smart logistics business platform model and innovation mechanism.
基金supported by the National Natural Science Foundation of China(61273198)
文摘Combat system effectiveness simulation (CSES) is a special type of complex system simulation. Three non-functional requirements (NFRs), i.e. model composability, domain specific modeling, and model evolvability, are gaining higher priority from CSES users when evaluating different modeling methodologies for CSES. Traditional CSES modeling methodologies are either domain-neutral (lack of domain characteristics consideration and limited support for model composability) or domain-oriented (lack of openness and evolvability) and fall short of the three NFRs. Inspired by the concept of architecture in systems engineering and software engineering fields, we extend it into a concept of model architecture for complex simulation systems, and propose a model architecture-oriented modeling methodology in which the model architecture plays a central role in achieving the three NFRs. Various model-driven engineering (MDE) approaches and technologies, including simulation modeling platform (SMP), unified modeling language (UML), domain specific modeling (DSM), eclipse modeling framework (EMF), graphical modeling framework (GMF), and so forth, are applied where possible in representing the CSES model architecture and its components' behaviors from physical and cognitive domain aspects. A prototype CSES system, called weapon effectiveness simulation system (WESS), and a non-trivial air-combat simulation example are presented to demonstrate the methodology.
基金Supported by the National Natural Science Foundation of China (90104005,60373087,60473023) and Key Laboratory of Geo-Informatics of State Bureau of Surveying and Mapping(200626)
文摘Trusted platform model （TPM） is special-purpose integrated circuits （ICs） built into a variety of platforms to enable strong user authentication and machine attestation-essential to prevent inappropriate access to confidential and sensitive information and to protect against compromised networks. Existing TPM products have some limitations. This paper adopts J2810TPM Single Chip cryptogram MCU produced by Jetway Company to construct typical TPM after comparing existing TPM products. Finally, an improved construction approach of TPM based on J2810 is proposed.
文摘Smart cities initiatives are developing all over the world, due to their support in favouring a better provision of services, in connection with the aim of achieving efficiency in cities management. More and more big corporations are interested in this topic to develop their businesses, as several issues are linked to these projects, like environment, water management, energy policies, education, culture, and so on. In literature these issues, known as drivers, were also related to sustainability aims which could be reached through the accomplishment of better performances within environment, economy, and society. This study synthesizes all the different drivers identified by scholars and industry players in a model, in order to use it as a framework to depict the linkages among the various smart cities projects. Since transport resulted as one of the most considered drivers in the analyzed contributions, the research questions were delineated to describe its role in the different phases of smart initiatives, and to understand if it could encourage and enable the other drivers＇ development. The multiple case study was chosen as the fittest methodological approach and it was conducted with the selection of three smart cities, one for each of the most cited platform models developed by industry players, which had started transport initiatives at least three years ago： Singapore （IBM）, Amsterdam （Accenture）, and San Francisco （Microsoft）. The analysis of the official documents set up by city departments and by the industry players showed transport as a driving force in smart cities projects which conveys a smart approach to different domains, especially energy savings, environment, and safety. The results also showed smart mobility as a pivot in stimulating investments and citizens＇ participation on different city drivers, especially as it concerns environment and services to both citizens and businesses. Smart transport initiatives, hardware and software infrastructures, technological devices, and people participation to smartization were closely interrelated in smart cities projects and they could be successfully used to achieve sustainability aims for different stakeholders.
基金supported by the National Natural Science Foundation of China(61271327)
文摘Bistatic/multistatic radar has great potential advantages over its monostatic counterpart. However, the separation of a transmitter and a receiver leads to difficulties in locating the target position accurately and guaranteeing space-timefrequency synchronization of the transmitter and the receiver.The error model of space-time-frequency synchronization in a motion platform of bistatic/multistatic radar is studied. The relationship between the space synchronization error and the transmitter platform position, receiver platform position, moving state, and beam pointing error, is analyzed. The effect of space synchronization error on target echo power is studied. The target scattering characteristics are restructured by many separate scattering centers of the target in high frequency regions. Based on the scattering centers model of the radar target, this radar target echo model and the simulation method are discussed. The algorithm of bistatic/multistatic radar target echo accurately reflects the scattering characteristics of the radar target, pulse modulation speciality of radar transmitting signals, and spacetime-frequency synchronization error characteristics between the transmitter station and the receiver station. The simulation of bistatic radar is completed in computer, and the results of the simulation validate the feasibility of the method.
基金supported in part by the National Institutes of Health under R01CA237267,R01HL151561,R01EB031102,and R01EB032716.
文摘In this perspective,"CASES"are made for AI in medicine.The CASES mean Confidence,Adaptability,Stability,Explainability,and Security of AI systems.We underline that these CASES can be addressed not only individually but also synergistically on the large model platform and using cutting-edge diffusion-type models.
基金supported by the Science and Technology Project of State Grid Corporation of China(No.5700-202258188A-1-1-ZN).
文摘Data storage security has become the core of many network security issues.In order to achieve trusted storage and trusted measurement of network community data,this paper proposes a secure storage model based on trust extension for existing trusted storage technologies.In the process of document encryption,the key information is encrypted as well as decentralized stored by optimizing the ciphertext inverted index structure and update policy to ensure the security of index information.In the process of user access control mechanism,SAML and XACML are used in combination with role-based access control in order to achieve flexible and efficient authorization and access control.In the process of result query,ontology technology is introduced to better express the user’s query intention and improve the query accuracy.A large number of experiments demonstrate the effectiveness and feasibility of the scheme.
