Integrating and sharing data from different data sources is one of the trends to make better use of data. However, data integration hampers data confidentiality where each data source has its own access control policy...Integrating and sharing data from different data sources is one of the trends to make better use of data. However, data integration hampers data confidentiality where each data source has its own access control policy. This paper includes a discussion on the issue about access control across multiple data sources when they arc combined together in the scenario of searching over these data. A method based on multilevel security for data integration is proposed. The proposed method allows the merging of policies and also tackles the issue of policy conflicts between different data sources.展开更多
China should pilot renewable energy integration policies similar to those adopted in Germany and Texas in the Beijing-Tianjin-Hebei region to transmit excess energy and reduce wasted wind power.Renewable energy integr...China should pilot renewable energy integration policies similar to those adopted in Germany and Texas in the Beijing-Tianjin-Hebei region to transmit excess energy and reduce wasted wind power.Renewable energy integration will be fundamental to China?s transition to a low-carbon economy.Although China now leads the world in terms展开更多
As one of the most popular visual programming languages,Scratch has a lot of evaluation around it.Reasonable evaluation can help programmers understand their projects better.At the same time,it can also provide a refe...As one of the most popular visual programming languages,Scratch has a lot of evaluation around it.Reasonable evaluation can help programmers understand their projects better.At the same time,it can also provide a reference for them to browse other projects in the online community.Most of the existing evaluations on Scratch are carried from three perspectives:Computational Thinking(CT)ability,visual presentation aesthetics,and code quality.Among them,the assessment of CT and code quality is mainly carried out from the program script,while the evaluation of visual aesthetics is analyzed from the perspective of image sequences generated by project execution.The single-view evaluation focuses on the performance of a program in a certain aspect and is one-sided.In this paper,we propose a multi-view evaluation framework to integrate various evaluations using different policies.We quantitatively analyze the assessment of different views driven by data.Combined with overall evaluations that represent human opinions,we analyze their differences and connections.Through experiments,we determine the weights of different integration policies,the proposed multi-view evaluation method can generate evaluation results similar to human opinions.展开更多
An appropriate spacing policy improves traffic flow and traffic efficiency while reducing commuting time and energy con-sumption.In this paper,the integrated spacing policy that combines the benefits of the constant t...An appropriate spacing policy improves traffic flow and traffic efficiency while reducing commuting time and energy con-sumption.In this paper,the integrated spacing policy that combines the benefits of the constant time headway(CTH)and safety distance(SD)spacing policies is proposed in an attempt to improve traffic flow and efficiency.Firstly,the performance of the CTH and SD spacing policies is analyzed from the perspective of the microscopic characteristics of human-vehicle and the macroscopic characteristics of traffic flow.The switching law between CTH and SD spacing policies and the integrated spacing policy are then proposed to increase traffic efficiency according to the traffic conditions,and the critical speed for the proposed integrated spacing policy is derived.Using the proposed switching law,the integrated spacing policy utilizes the safety redundancy difference between the CTH and SD spacing policies in a flexible manner.Simulation tests demon-strate that the proposed integrated spacing policy increases traffic flow and that the traffic flow maintains string stability in a wider range of traffic flow density.展开更多
On May 6,2019,the CPC Central Committee and State Council released the Opinions Concerning Establishing and Improving the Institution,Mechanism,and Policy System for Urban and Rural Integrated Development(shortened in...On May 6,2019,the CPC Central Committee and State Council released the Opinions Concerning Establishing and Improving the Institution,Mechanism,and Policy System for Urban and Rural Integrated Development(shortened into the Opinions in the following part).The Opinions suggests that by 2022,a primary urban-rural integrated development mechanism should be established.An institutional channel for free flowing of urban and rural elements should be basically opened up,the restrictions on urban permanent household registration should be gradually eliminated,the unified urban and rural construction land use market should be set up,the capacity of finance serving for countryside revitalization should be apparently promoted.展开更多
The growing water stress both in terms of water scarcity and quality deterioration promotes the development of reclaimed water as a new water resource use. This paper reviewed wastewater reuse practices in China, and ...The growing water stress both in terms of water scarcity and quality deterioration promotes the development of reclaimed water as a new water resource use. This paper reviewed wastewater reuse practices in China, and the opportunities and challenges of expanding reclaimed water use were analyzed. Rapid urbanization with the increasing of water demand and wastewater discharge provides an opportunity for wastewater reuse. The vast amount of wastewater discharge and low reclaimed water production mean that wastewater reuse still has a great potential in China. Many environmental and economic benefits and successful reclamation technologies also provide opportunities for wastewater reuse. In addition, the overall strategy in China is also encouraging for wastewater reuse. In the beginning stage of wastewater reclamation and reuse, there are many significant challenges to expand wastewater reuse in China including slow pace in adopting urban wastewater reuse programs, the establishment of integrated water resources management framework and guidelines for wastewater reuse programs, incoherent water quality requirements, the limited commercial development of reclaimed water and the strengthening of public awareness and cooperation among stakeholders.展开更多
In order to provide integrity protection for the secure operating system to satisfy the structured protection class' requirements, a DTE technique based integrity protection formalization model is proposed after the ...In order to provide integrity protection for the secure operating system to satisfy the structured protection class' requirements, a DTE technique based integrity protection formalization model is proposed after the implications and structures of the integrity policy have been analyzed in detail. This model consists of some basic rules for configuring DTE and a state transition model, which are used to instruct how the domains and types are set, and how security invariants obtained from initial configuration are maintained in the process of system transition respectively. In this model, ten invariants are introduced, especially, some new invariants dealing with information flow are proposed, and their relations with corresponding invariants described in literatures are also discussed. The thirteen transition rules with well-formed atomicity are presented in a well-operational manner. The basic security theorems correspond to these invariants and transition rules are proved. The rationalities for proposing the invariants are further annotated via analyzing the differences between this model and ones described in literatures. At last but not least, future works are prospected, especially, it is pointed out that it is possible to use this model to analyze SE-Linux security.展开更多
基金Supported by the China MOE-China Mobile Research Fund(MCM20121051,MCM20130651)China MOE Doctoral Research Fund(20134407120017)+2 种基金Natural Science Foundation of Guangdong Province(S2012030006242)Guangdong Industry Development Fund(S2014-007)Guangzhou Industry Cooperation Fund(2014Y2-00004,2014Y2-00006)
文摘Integrating and sharing data from different data sources is one of the trends to make better use of data. However, data integration hampers data confidentiality where each data source has its own access control policy. This paper includes a discussion on the issue about access control across multiple data sources when they arc combined together in the scenario of searching over these data. A method based on multilevel security for data integration is proposed. The proposed method allows the merging of policies and also tackles the issue of policy conflicts between different data sources.
文摘China should pilot renewable energy integration policies similar to those adopted in Germany and Texas in the Beijing-Tianjin-Hebei region to transmit excess energy and reduce wasted wind power.Renewable energy integration will be fundamental to China?s transition to a low-carbon economy.Although China now leads the world in terms
基金supported by the National Natural Science Foundation of China(Nos.62272052 and 62172051).
文摘As one of the most popular visual programming languages,Scratch has a lot of evaluation around it.Reasonable evaluation can help programmers understand their projects better.At the same time,it can also provide a reference for them to browse other projects in the online community.Most of the existing evaluations on Scratch are carried from three perspectives:Computational Thinking(CT)ability,visual presentation aesthetics,and code quality.Among them,the assessment of CT and code quality is mainly carried out from the program script,while the evaluation of visual aesthetics is analyzed from the perspective of image sequences generated by project execution.The single-view evaluation focuses on the performance of a program in a certain aspect and is one-sided.In this paper,we propose a multi-view evaluation framework to integrate various evaluations using different policies.We quantitatively analyze the assessment of different views driven by data.Combined with overall evaluations that represent human opinions,we analyze their differences and connections.Through experiments,we determine the weights of different integration policies,the proposed multi-view evaluation method can generate evaluation results similar to human opinions.
基金Special thanks are due to the National Natural Science Foundation of China[51675217,61790564]the Young Elite Scientists Sponsorship Program by CAST[2016QNRC001]+1 种基金the China Automobile Industry Innovation and Development Joint Fund[U1564213]the Opening Founding of State Key Laboratory of Automotive Simulation and Control[20161114]for supporting authors’research.
文摘An appropriate spacing policy improves traffic flow and traffic efficiency while reducing commuting time and energy con-sumption.In this paper,the integrated spacing policy that combines the benefits of the constant time headway(CTH)and safety distance(SD)spacing policies is proposed in an attempt to improve traffic flow and efficiency.Firstly,the performance of the CTH and SD spacing policies is analyzed from the perspective of the microscopic characteristics of human-vehicle and the macroscopic characteristics of traffic flow.The switching law between CTH and SD spacing policies and the integrated spacing policy are then proposed to increase traffic efficiency according to the traffic conditions,and the critical speed for the proposed integrated spacing policy is derived.Using the proposed switching law,the integrated spacing policy utilizes the safety redundancy difference between the CTH and SD spacing policies in a flexible manner.Simulation tests demon-strate that the proposed integrated spacing policy increases traffic flow and that the traffic flow maintains string stability in a wider range of traffic flow density.
文摘On May 6,2019,the CPC Central Committee and State Council released the Opinions Concerning Establishing and Improving the Institution,Mechanism,and Policy System for Urban and Rural Integrated Development(shortened into the Opinions in the following part).The Opinions suggests that by 2022,a primary urban-rural integrated development mechanism should be established.An institutional channel for free flowing of urban and rural elements should be basically opened up,the restrictions on urban permanent household registration should be gradually eliminated,the unified urban and rural construction land use market should be set up,the capacity of finance serving for countryside revitalization should be apparently promoted.
基金supported by the National Natural Science Foundation of China(No.41271501)
文摘The growing water stress both in terms of water scarcity and quality deterioration promotes the development of reclaimed water as a new water resource use. This paper reviewed wastewater reuse practices in China, and the opportunities and challenges of expanding reclaimed water use were analyzed. Rapid urbanization with the increasing of water demand and wastewater discharge provides an opportunity for wastewater reuse. The vast amount of wastewater discharge and low reclaimed water production mean that wastewater reuse still has a great potential in China. Many environmental and economic benefits and successful reclamation technologies also provide opportunities for wastewater reuse. In addition, the overall strategy in China is also encouraging for wastewater reuse. In the beginning stage of wastewater reclamation and reuse, there are many significant challenges to expand wastewater reuse in China including slow pace in adopting urban wastewater reuse programs, the establishment of integrated water resources management framework and guidelines for wastewater reuse programs, incoherent water quality requirements, the limited commercial development of reclaimed water and the strengthening of public awareness and cooperation among stakeholders.
基金supported by the Beijing Natural Science Foundation(Grant No.4052016)the National Natural Science Foundation of China(Grant No.60573042)the National Grand Fundamental Research 973 Program of China(Grant No.G1999035802).
文摘In order to provide integrity protection for the secure operating system to satisfy the structured protection class' requirements, a DTE technique based integrity protection formalization model is proposed after the implications and structures of the integrity policy have been analyzed in detail. This model consists of some basic rules for configuring DTE and a state transition model, which are used to instruct how the domains and types are set, and how security invariants obtained from initial configuration are maintained in the process of system transition respectively. In this model, ten invariants are introduced, especially, some new invariants dealing with information flow are proposed, and their relations with corresponding invariants described in literatures are also discussed. The thirteen transition rules with well-formed atomicity are presented in a well-operational manner. The basic security theorems correspond to these invariants and transition rules are proved. The rationalities for proposing the invariants are further annotated via analyzing the differences between this model and ones described in literatures. At last but not least, future works are prospected, especially, it is pointed out that it is possible to use this model to analyze SE-Linux security.