These days,data is regarded as a valuable asset in the era of the data economy,which demands a trading platform for buying and selling data.However,online data trading poses challenges in terms of security and fairnes...These days,data is regarded as a valuable asset in the era of the data economy,which demands a trading platform for buying and selling data.However,online data trading poses challenges in terms of security and fairness because the seller and the buyer may not fully trust each other.Therefore,in this paper,a blockchain-based secure and fair data trading system is proposed by taking advantage of the smart contract and matchmaking encryption.The proposed system enables bilateral authorization,where data trading between a seller and a buyer is accomplished only if their policies,required by each other,are satisfied simultaneously.This can be achieved by exploiting the security features of the matchmaking encryption.To guarantee non-repudiation and fairness between trading parties,the proposed system leverages a smart contract to ensure that the parties honestly carry out the data trading protocol.However,the smart contract in the proposed system does not include complex cryptographic operations for the efficiency of onchain processes.Instead,these operations are carried out by off-chain parties and their results are used as input for the on-chain procedure.The system also uses an arbitration protocol to resolve disputes based on the trading proof recorded on the blockchain.The performance of the protocol is evaluated in terms of off-chain computation overhead and on-chain gas consumption.The results of the experiments demonstrate that the proposed protocols can enable the implementation of a cost-effective data trading system.展开更多
The specification of authorization policies in access control models proposed so far cannot satisfy the requirements in workflow management systems(WFMSs).Furthermore,existing approaches have not provided effective co...The specification of authorization policies in access control models proposed so far cannot satisfy the requirements in workflow management systems(WFMSs).Furthermore,existing approaches have not provided effective conflict detection and resolution methods to maintain the consistency of authorization polices in WFMSs.To address these concerns,we propose the definition of authorization policies in which context constraints are considered and the complicated requirements in WFMSs can be satisfied.Based on the definition,we put forward static and dynamic conflict detection methods for authorization policies.By defining two new concepts,the precedence establishment rule and the conflict resolution policy,we provide a flexible approach to resolving conflicts.展开更多
User-centric data sharing is essential to encourage citizens'active participation in the digital economy.One key to smart cities,a form of the digital economy,is the promotion of public use of citizen data.Neverth...User-centric data sharing is essential to encourage citizens'active participation in the digital economy.One key to smart cities,a form of the digital economy,is the promotion of public use of citizen data.Nevertheless,it is not easy to utilize data without citizens’consent.In this study,we took a technological approach to these issues.Usermanaged access(UMA)is a well-known framework for delegating resource access rights to others on the Internet.In UMA,authorization mechanisms are designed to be centralized so that resource owners can centrally manage access rights for various resources stored in different domains.However,the lack of transparency in the authorization mechanism is a barrier to its implementation in large-scale systems such as smart cities.In this study,we developed a blockchain-based cross-domain authorization architecture that enables a resource-sharing ecosystem in which organizations that wish to utilize data can freely trade with each other.The proposed architecture solves the transparency problem that conventional authorization systems have had by designing the authorization mechanism on blockchain technology.We implemented the proposed architecture as smart contracts and evaluated its processing performance.The resultant time required for delegating access rights and accessing resources was less than 500 ms.Furthermore,we found that the fluctuation in the processing time overhead was small.Based on these results,we concluded that performance degradation with the proposed architecture is minor.展开更多
Objective To provide suggestions for helping marketing authorization holders(MAHs)to develop an effective and compliant pharmacovigilance system.Methods The construction strategies of pharmacovigilance system of the m...Objective To provide suggestions for helping marketing authorization holders(MAHs)to develop an effective and compliant pharmacovigilance system.Methods The construction strategies of pharmacovigilance system of the multinational pharmaceutical companies were analyzed based on the requirements of regulations and laws.Results and Conclusion There are some gaps between local and multinational pharmaceutical companies in the construction of pharmacovigilance system.We can learn from the experience of multinational pharmaceutical companies to improve the pharmacovigilance system,which includes building a sound pharmacovigilance organizational structure,establishing a series of operational system files and cultivating professional talents.MAHs of China should improve the structure of enterprise pharmacovigilance system.Besides,members of Drug Safety Committee should be department managers with higher position so that they can fulfil the responsibilities of risk assessment.If MAHs possess a large variety and quantity of products,a Drug Safety Committee should be established to ensure the timely discovery of risks.In addition,MAHs should pay attention to the implementation of related regulations and laws on pharmacovigilance and establish compliant,effective and operatable files combing with the actual operation of pharmacovigilance system.Finally,MAHs should introduce and train pharmacovigilance talents,and hire pharmacovigilance experts as consultants to solve the problem of talent shortage.展开更多
Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclusively to the editorial department of Meteorological and Environmental Research the digital repro...Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclusively to the editorial department of Meteorological and Environmental Research the digital reproduction,distribution,compilation and information network transmission rights.展开更多
Should the article be accepted and published by Agricultural Science&Technology,the author hereby grants exclusively to the editorial department of Agricultural Science&Technology the digital reproduction,dist...Should the article be accepted and published by Agricultural Science&Technology,the author hereby grants exclusively to the editorial department of Agricultural Science&Technology the digital reproduction,distribution,compilation and information network transmission rights.展开更多
Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclusively to the editorial department of Meteorological and Environmental Research the digital repro...Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclusively to the editorial department of Meteorological and Environmental Research the digital reproduction,distribution,compilation and information network transmission rights.展开更多
Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclusively to the editorial department of Meteorological and Environmental Research the digital repro...Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclusively to the editorial department of Meteorological and Environmental Research the digital reproduction,distribution,compilation and information network transmission rights.展开更多
Should the article be accepted and published by Agricultural Science&Technology,the author hereby grants exclusively to the editorial department of Agricultural Science&Technology the digital reproduction,dist...Should the article be accepted and published by Agricultural Science&Technology,the author hereby grants exclusively to the editorial department of Agricultural Science&Technology the digital reproduction,distribution,compilation and information network transmission rights.展开更多
Objective To ensure the quality and safety of drugs in the whole cycle of pharmaceutical commissioned production under the drug marketing authorization holder(MAH)system,and to establish a perfect quality management s...Objective To ensure the quality and safety of drugs in the whole cycle of pharmaceutical commissioned production under the drug marketing authorization holder(MAH)system,and to establish a perfect quality management system for it.Methods Literature review was used to study the factors that influenced the quality management system of pharmaceutical commissioned production because the implementation of MAH system in China was late,and the experience accumulated by pharmaceutical industry was not enough.Results and Conclusion Based on the MAH system,it is of great significance to establish the quality management system for pharmaceutical commissioned production.展开更多
BACKGROUND Systematic reviews(SRs)synthesize and evaluate data,mainly from randomized trials,which then guides the development of clinical recommendations in evidence-based medicine.However,the data and methodological...BACKGROUND Systematic reviews(SRs)synthesize and evaluate data,mainly from randomized trials,which then guides the development of clinical recommendations in evidence-based medicine.However,the data and methodological information in the included papers can often be lacking or unclear,and reviewers usually need to contact the authors of included studies for clarifications.Contacting authors is recommended,but it is unclear how often SR teams do it,or what the level of response is.AIM To investigate how often reviewers undertake contact with the authors of included randomized controlled trials(RCTs)for clarification on data and risk of bias concerns,to explore the factors that influence whether SR authors contact or do not contact the authors,and the content and level of responses.METHODS We conducted a systematic electronic database search in MEDLINE using the search string“(systematic review)”AND“(RCT OR randomized OR trial)”for articles published between 1 January 2024 and 19 February 2024,without language restrictions.Screening and data extraction was done independently by two reviewers,and conflicts resolved by a senior author.Contact authors of included SRs were contacted for clarifications.RESULTS Of the 329 included SRs,38%(n=125)explicitly mentioned contact with the authors of included studies.The remaining 62%(n=204)did not.We attempted contact with all SR teams for clarifications and received 90 responses(19.4%).Of the 50 respondents who did not explicitly mention contact in their SRs,25(50%)replied that they did make contact.We received a total of 64 responses on the level and content of information sought.The mean±SD contacts SR teams made were 10(10),replies received 5(6.7),and response waiting time 10.1(28.3)weeks.Resources,time,poor previous experience,perceived likelihood of poor response and bias concerns were reported as barriers to attempting contact.CONCLUSION The majority of SRs published in 2024 did not confirm seeking clarifying or missing information from primary study authors.However,SR teams reported that 50%of contacted primary authors respond.Additional research can clarify this rate of response and establish methods to increase the integration of this core methodological element in SRs.展开更多
According to the Charter of the United Nations,the United Nations Security Council adopts a“collective security system”authorized voting system,which has prominent drawbacks such as difficulty in fully reflecting th...According to the Charter of the United Nations,the United Nations Security Council adopts a“collective security system”authorized voting system,which has prominent drawbacks such as difficulty in fully reflecting the will of all Member States.Combining interdisciplinary,qualitative and quantitative research methods,in response to the dilemma of Security Council voting reform,this article suggests retaining the Security Council voting system and recommending a simplified model of“basic and weighted half”for voting allocation.This model not only inherits the authorized voting system of the collective security system,but also follows the allocation system of sovereignty equality in the Charter.It can also achieve the“draw on the advantages and avoid disadvantages”of Member States towards international development,promote the transformation of“absolute equality”of overall consistency into“real fairness”relative to individual contributions,and further promote the development of international law in the United Nations voting system.展开更多
International Journal of Minerals,Metallurgy and Materials is dedicated to the publication and the dissemination of original research articles (and occasional invited reviews) in the fields of Minerals,Metallurgy and ...International Journal of Minerals,Metallurgy and Materials is dedicated to the publication and the dissemination of original research articles (and occasional invited reviews) in the fields of Minerals,Metallurgy and Materials.It is covered by EI Compendex,SCI Expanded,Chemical Abstract,etc.Manuscript preparation The following components are required for a complete manuscript:Title,Author(s),Author affiliation(s),Abstract,Keywords,Main text,Acknowledgements and References.展开更多
Community Question Answering （CQA） websites have greatly facilitated users＇ lives, with an increasing number of people seeking help and exchanging ideas on the Internet. This newlymerged community features two char...Community Question Answering （CQA） websites have greatly facilitated users＇ lives, with an increasing number of people seeking help and exchanging ideas on the Internet. This newlymerged community features two characteristics： social relations and an ask-reply mechanism. As users＇ behaviours and social statuses play a more important role in CQA services than traditional answer retrieving websites, researchers＇ concerns have shifted from the need to passively find existing answers to actively seeking potential reply providers that may give answers in the near future. We analyse datasets derived from an online CQA system named ＂Quora＂, and observed that compared with traditional question answering services, users tend to contribute replies rather than questions for help in the CQA system. Inspired by the findings, we seek ways to evaluate the users＇ ability to offer prompt and reliable help, taking into account activity, authority and social reputation char- acteristics. We propose a hybrid method that is based on a Question-User network and social network using optimised PageRank algorithm. Experimental results show the efficiency of the proposed method for ranking potential answer-providers.展开更多
Mine reclamation bonds are used in countries with mineral mining to ensure that reclamation of the mined area is completed. The United States, Canada, and Australia are countries with established mine reclamation bond...Mine reclamation bonds are used in countries with mineral mining to ensure that reclamation of the mined area is completed. The United States, Canada, and Australia are countries with established mine reclamation bond programs, with the United States coal system having been in place since 1977. China implemented a bonding system in 1998 and by 2013 all 31 provinces had established a system. An effective bonding system must be conditioned on fair and enforceable nationwide reclamation standard, stimulate companies to conduct reclamation by forming economic incentives rather than penalties that become a liability, and allow for full public participation. Based on these principles, this paper compares seven important factors for a successful reclamation bonding system： laws and regulations, administrative authority, bond types, bond size, calculation method, bond release, and public participation. The results show variation in policies and procedures for bonding among countries. Using principles and policies primarily from the United States, China should establish a national reclamation bonding system with legislation that forms a national authority to oversee and enforce reclamation standards and bond requirements. In addition, China can expand bond financial types and strategies, set the size of reclamation bonds at the level of a third-party reclamation cost, and set unified standards for calculation. Phased bond release should be established with specific reclamation criteria for each phase of release. Finally, bonding regulations should clearly identify opportunities for full public participation in the process.展开更多
Time-limited dispatching(TLD)analysis of the full authority digital engine control(FADEC)systems is an important part of the aircraft system safety analysis and a necessary task for the certification of commercial air...Time-limited dispatching(TLD)analysis of the full authority digital engine control(FADEC)systems is an important part of the aircraft system safety analysis and a necessary task for the certification of commercial aircraft and aeroengines.In the time limited dispatch guidance document ARP5107B,a single-fault Markov model(MM)approach is proposed for TLD analysis.However,ARP5107B also requires that the loss of thrust control(LOTC)rate error calculated by applying the single-fault MM must be less than 5%when performing airworthiness certification.Firstly,the sources of accuracy errors in three kinds of MM are analyzed and specified through a case study of the general FADEC system,and secondly a two-fault MM considering maintenance policy is established through analyzing and calculating the expected repair time when two related faults happen.Finally,a specific FADEC system is given to study on the influence factors of accuracy error in the single-fault MM,and the results show that the accuracy error of the single-fault MM decreases with the increase of short or long prescribed dispatch time,and the range values of short time(ST)and long time(LT)are determined to satisfy the requirement of accuracy error within 5%.展开更多
Authorization management is important precondition and foundation for coordinating and resource sharing in open networks. Recently, authorization based on trust is widely used whereby access rights to shared resource ...Authorization management is important precondition and foundation for coordinating and resource sharing in open networks. Recently, authorization based on trust is widely used whereby access rights to shared resource are granted on the basis of their trust relation in distributed environment. Nevertheless, dynamic change of the status of credential and chain of trust induces to uncertainty of trust relation. Considering uncertainty of authorization and analyzing deficiency of authorization model only based on trust, we proposes joint trust-risk evaluation and build the model based on fuzzy set theory, and make use of the membership grade of fuzzy set to express joint trust-risk relation. Finally, derivation principle and constraint principle of joint trust-risk relationships are presented. The authorization management model is defined based on joint trust-risk evaluation, proof of compliance and separation of duty are analyzed. The proposed model depicts not only trust relationship between principals, but also security problem of authorization.展开更多
A workflow authorization model based on credentials was proposesed. It can nicely satisfy the features that workflows in actual application should satisfying. This model uses access control list based on task state wh...A workflow authorization model based on credentials was proposesed. It can nicely satisfy the features that workflows in actual application should satisfying. This model uses access control list based on task state which nicely ensure synchronizing authorization flow with workflow; specifies authorization policy not only based on user identifiers but also based on user qualifications and characteristics; defines a set of constraint rules for a task and seek the eligible users to execute the task according to the type of each constraint rule which realize dynamic separation of duty; and realizes the access granularity of authorization ranging from objects to specific parts of objects which ensure the least privilege constraints much more better.展开更多
Quantum authorization management(QAM)is the quantum scheme for privilege management infrastructure(PMI)problem.Privilege management(authorization management)includes authentication and authorization.Authentication is ...Quantum authorization management(QAM)is the quantum scheme for privilege management infrastructure(PMI)problem.Privilege management(authorization management)includes authentication and authorization.Authentication is to verify a user’s identity.Authorization is the process of verifying that a authenticated user has the authority to perform a operation,which is more fine-grained.In most classical schemes,the authority management center(AMC)manages the resources permissions for all network nodes within the jurisdiction.However,the existence of AMC may be the weakest link of the whole scheme.In this paper,a protocol for QAM without AMC is proposed based on entanglement swapping.In this protocol,Bob(the owner of resources)authenticates the legality of Alice(the user)and then shares the right key for the resources with Alice.Compared with the other existed QAM protocols,this protocol not only implements authentication,but also authorizes the user permissions to access certain resources or carry out certain actions.The authority division is extended to fin-grained rights division.The security is analyzed from the four aspects:the outsider’s attack,the user’s attack,authentication and comparison with the other two QAM protocols.展开更多
Due to the mobility of users in an organization,inclusion of dynamic attributes such as time and location becomes the major challenge in Ciphertext-Policy Attribute-Based Encryption(CP-ABE).By considering this challen...Due to the mobility of users in an organization,inclusion of dynamic attributes such as time and location becomes the major challenge in Ciphertext-Policy Attribute-Based Encryption(CP-ABE).By considering this challenge;we focus to present dynamic time and location information in CP-ABE with mul-ti-authorization.Atfirst,along with the set of attributes of the users,their corre-sponding location is also embedded.Geohash is used to encode the latitude and longitude of the user’s position.Then,decrypt time period and access time period of users are defined using the new time tree(NTT)structure.The NTT sets the encrypted duration of the encrypted data and the valid access time of the private key on the data user’s private key.Besides,single authorization of attribute authority(AA)is extended as multi authorization for enhancing the effectiveness of key generation.Simulation results depict that the proposed CP-ABE achieves better encryption time,decryption time,security level and memory usage.Namely,encryption time and decryption time of the proposed CP-ABE are reduced to 19%and 16%than that of existing CP-ABE scheme.展开更多
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2022R1I1A3063257)supported by Electronics and Telecommunications Research Institute(ETRI)grant funded by the Korean Government[22ZR1300,Research on Intelligent Cyber Security and Trust Infra].
文摘These days,data is regarded as a valuable asset in the era of the data economy,which demands a trading platform for buying and selling data.However,online data trading poses challenges in terms of security and fairness because the seller and the buyer may not fully trust each other.Therefore,in this paper,a blockchain-based secure and fair data trading system is proposed by taking advantage of the smart contract and matchmaking encryption.The proposed system enables bilateral authorization,where data trading between a seller and a buyer is accomplished only if their policies,required by each other,are satisfied simultaneously.This can be achieved by exploiting the security features of the matchmaking encryption.To guarantee non-repudiation and fairness between trading parties,the proposed system leverages a smart contract to ensure that the parties honestly carry out the data trading protocol.However,the smart contract in the proposed system does not include complex cryptographic operations for the efficiency of onchain processes.Instead,these operations are carried out by off-chain parties and their results are used as input for the on-chain procedure.The system also uses an arbitration protocol to resolve disputes based on the trading proof recorded on the blockchain.The performance of the protocol is evaluated in terms of off-chain computation overhead and on-chain gas consumption.The results of the experiments demonstrate that the proposed protocols can enable the implementation of a cost-effective data trading system.
基金supported by the National Natural Science Foundation of China (Nos.50705084 and 60473129)the Science and Technology Plan of Zhejiang Province,China (No.2007C13018)
文摘The specification of authorization policies in access control models proposed so far cannot satisfy the requirements in workflow management systems(WFMSs).Furthermore,existing approaches have not provided effective conflict detection and resolution methods to maintain the consistency of authorization polices in WFMSs.To address these concerns,we propose the definition of authorization policies in which context constraints are considered and the complicated requirements in WFMSs can be satisfied.Based on the definition,we put forward static and dynamic conflict detection methods for authorization policies.By defining two new concepts,the precedence establishment rule and the conflict resolution policy,we provide a flexible approach to resolving conflicts.
基金supported by JSPS KAKENHI(Grant Number JP19K11963,JP22K17881,JP18K04133,and JP22H00550).
文摘User-centric data sharing is essential to encourage citizens'active participation in the digital economy.One key to smart cities,a form of the digital economy,is the promotion of public use of citizen data.Nevertheless,it is not easy to utilize data without citizens’consent.In this study,we took a technological approach to these issues.Usermanaged access(UMA)is a well-known framework for delegating resource access rights to others on the Internet.In UMA,authorization mechanisms are designed to be centralized so that resource owners can centrally manage access rights for various resources stored in different domains.However,the lack of transparency in the authorization mechanism is a barrier to its implementation in large-scale systems such as smart cities.In this study,we developed a blockchain-based cross-domain authorization architecture that enables a resource-sharing ecosystem in which organizations that wish to utilize data can freely trade with each other.The proposed architecture solves the transparency problem that conventional authorization systems have had by designing the authorization mechanism on blockchain technology.We implemented the proposed architecture as smart contracts and evaluated its processing performance.The resultant time required for delegating access rights and accessing resources was less than 500 ms.Furthermore,we found that the fluctuation in the processing time overhead was small.Based on these results,we concluded that performance degradation with the proposed architecture is minor.
基金Integration Application Status and Problems Investigation of ICH Q8,Q9,Q10 across the Product Life Cycle(No.20210605).
文摘Objective To provide suggestions for helping marketing authorization holders(MAHs)to develop an effective and compliant pharmacovigilance system.Methods The construction strategies of pharmacovigilance system of the multinational pharmaceutical companies were analyzed based on the requirements of regulations and laws.Results and Conclusion There are some gaps between local and multinational pharmaceutical companies in the construction of pharmacovigilance system.We can learn from the experience of multinational pharmaceutical companies to improve the pharmacovigilance system,which includes building a sound pharmacovigilance organizational structure,establishing a series of operational system files and cultivating professional talents.MAHs of China should improve the structure of enterprise pharmacovigilance system.Besides,members of Drug Safety Committee should be department managers with higher position so that they can fulfil the responsibilities of risk assessment.If MAHs possess a large variety and quantity of products,a Drug Safety Committee should be established to ensure the timely discovery of risks.In addition,MAHs should pay attention to the implementation of related regulations and laws on pharmacovigilance and establish compliant,effective and operatable files combing with the actual operation of pharmacovigilance system.Finally,MAHs should introduce and train pharmacovigilance talents,and hire pharmacovigilance experts as consultants to solve the problem of talent shortage.
文摘Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclusively to the editorial department of Meteorological and Environmental Research the digital reproduction,distribution,compilation and information network transmission rights.
文摘Should the article be accepted and published by Agricultural Science&Technology,the author hereby grants exclusively to the editorial department of Agricultural Science&Technology the digital reproduction,distribution,compilation and information network transmission rights.
文摘Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclusively to the editorial department of Meteorological and Environmental Research the digital reproduction,distribution,compilation and information network transmission rights.
文摘Should the article be accepted and published by Meteorological and Environmental Research,the author hereby grants exclusively to the editorial department of Meteorological and Environmental Research the digital reproduction,distribution,compilation and information network transmission rights.
文摘Should the article be accepted and published by Agricultural Science&Technology,the author hereby grants exclusively to the editorial department of Agricultural Science&Technology the digital reproduction,distribution,compilation and information network transmission rights.
文摘Objective To ensure the quality and safety of drugs in the whole cycle of pharmaceutical commissioned production under the drug marketing authorization holder(MAH)system,and to establish a perfect quality management system for it.Methods Literature review was used to study the factors that influenced the quality management system of pharmaceutical commissioned production because the implementation of MAH system in China was late,and the experience accumulated by pharmaceutical industry was not enough.Results and Conclusion Based on the MAH system,it is of great significance to establish the quality management system for pharmaceutical commissioned production.
文摘BACKGROUND Systematic reviews(SRs)synthesize and evaluate data,mainly from randomized trials,which then guides the development of clinical recommendations in evidence-based medicine.However,the data and methodological information in the included papers can often be lacking or unclear,and reviewers usually need to contact the authors of included studies for clarifications.Contacting authors is recommended,but it is unclear how often SR teams do it,or what the level of response is.AIM To investigate how often reviewers undertake contact with the authors of included randomized controlled trials(RCTs)for clarification on data and risk of bias concerns,to explore the factors that influence whether SR authors contact or do not contact the authors,and the content and level of responses.METHODS We conducted a systematic electronic database search in MEDLINE using the search string“(systematic review)”AND“(RCT OR randomized OR trial)”for articles published between 1 January 2024 and 19 February 2024,without language restrictions.Screening and data extraction was done independently by two reviewers,and conflicts resolved by a senior author.Contact authors of included SRs were contacted for clarifications.RESULTS Of the 329 included SRs,38%(n=125)explicitly mentioned contact with the authors of included studies.The remaining 62%(n=204)did not.We attempted contact with all SR teams for clarifications and received 90 responses(19.4%).Of the 50 respondents who did not explicitly mention contact in their SRs,25(50%)replied that they did make contact.We received a total of 64 responses on the level and content of information sought.The mean±SD contacts SR teams made were 10(10),replies received 5(6.7),and response waiting time 10.1(28.3)weeks.Resources,time,poor previous experience,perceived likelihood of poor response and bias concerns were reported as barriers to attempting contact.CONCLUSION The majority of SRs published in 2024 did not confirm seeking clarifying or missing information from primary study authors.However,SR teams reported that 50%of contacted primary authors respond.Additional research can clarify this rate of response and establish methods to increase the integration of this core methodological element in SRs.
文摘According to the Charter of the United Nations,the United Nations Security Council adopts a“collective security system”authorized voting system,which has prominent drawbacks such as difficulty in fully reflecting the will of all Member States.Combining interdisciplinary,qualitative and quantitative research methods,in response to the dilemma of Security Council voting reform,this article suggests retaining the Security Council voting system and recommending a simplified model of“basic and weighted half”for voting allocation.This model not only inherits the authorized voting system of the collective security system,but also follows the allocation system of sovereignty equality in the Charter.It can also achieve the“draw on the advantages and avoid disadvantages”of Member States towards international development,promote the transformation of“absolute equality”of overall consistency into“real fairness”relative to individual contributions,and further promote the development of international law in the United Nations voting system.
文摘International Journal of Minerals,Metallurgy and Materials is dedicated to the publication and the dissemination of original research articles (and occasional invited reviews) in the fields of Minerals,Metallurgy and Materials.It is covered by EI Compendex,SCI Expanded,Chemical Abstract,etc.Manuscript preparation The following components are required for a complete manuscript:Title,Author(s),Author affiliation(s),Abstract,Keywords,Main text,Acknowledgements and References.
基金supported by the Fundamental Research Funds for the Central Universitiesthe National Natural Science Foundation of China under Grant No.61271041+2 种基金the National Basic Research Program of China (973 Program) under Grant No.2009CB320504the iCore Integrated Project under Grant No.287708the National Scienceand Technology Major Project under Grants No.2012ZX03005008-001,No.2012ZX03002008
文摘Community Question Answering （CQA） websites have greatly facilitated users＇ lives, with an increasing number of people seeking help and exchanging ideas on the Internet. This newlymerged community features two characteristics： social relations and an ask-reply mechanism. As users＇ behaviours and social statuses play a more important role in CQA services than traditional answer retrieving websites, researchers＇ concerns have shifted from the need to passively find existing answers to actively seeking potential reply providers that may give answers in the near future. We analyse datasets derived from an online CQA system named ＂Quora＂, and observed that compared with traditional question answering services, users tend to contribute replies rather than questions for help in the CQA system. Inspired by the findings, we seek ways to evaluate the users＇ ability to offer prompt and reliable help, taking into account activity, authority and social reputation char- acteristics. We propose a hybrid method that is based on a Question-User network and social network using optimised PageRank algorithm. Experimental results show the efficiency of the proposed method for ranking potential answer-providers.
文摘Mine reclamation bonds are used in countries with mineral mining to ensure that reclamation of the mined area is completed. The United States, Canada, and Australia are countries with established mine reclamation bond programs, with the United States coal system having been in place since 1977. China implemented a bonding system in 1998 and by 2013 all 31 provinces had established a system. An effective bonding system must be conditioned on fair and enforceable nationwide reclamation standard, stimulate companies to conduct reclamation by forming economic incentives rather than penalties that become a liability, and allow for full public participation. Based on these principles, this paper compares seven important factors for a successful reclamation bonding system： laws and regulations, administrative authority, bond types, bond size, calculation method, bond release, and public participation. The results show variation in policies and procedures for bonding among countries. Using principles and policies primarily from the United States, China should establish a national reclamation bonding system with legislation that forms a national authority to oversee and enforce reclamation standards and bond requirements. In addition, China can expand bond financial types and strategies, set the size of reclamation bonds at the level of a third-party reclamation cost, and set unified standards for calculation. Phased bond release should be established with specific reclamation criteria for each phase of release. Finally, bonding regulations should clearly identify opportunities for full public participation in the process.
基金supported by the National Natural Science Foundation of China(51705242)Shanghai Sailing Program(16YF1404900)the Fundamental Research Funds for the Central Universities(NS2015072)
文摘Time-limited dispatching(TLD)analysis of the full authority digital engine control(FADEC)systems is an important part of the aircraft system safety analysis and a necessary task for the certification of commercial aircraft and aeroengines.In the time limited dispatch guidance document ARP5107B,a single-fault Markov model(MM)approach is proposed for TLD analysis.However,ARP5107B also requires that the loss of thrust control(LOTC)rate error calculated by applying the single-fault MM must be less than 5%when performing airworthiness certification.Firstly,the sources of accuracy errors in three kinds of MM are analyzed and specified through a case study of the general FADEC system,and secondly a two-fault MM considering maintenance policy is established through analyzing and calculating the expected repair time when two related faults happen.Finally,a specific FADEC system is given to study on the influence factors of accuracy error in the single-fault MM,and the results show that the accuracy error of the single-fault MM decreases with the increase of short or long prescribed dispatch time,and the range values of short time(ST)and long time(LT)are determined to satisfy the requirement of accuracy error within 5%.
基金Supported by the National Natural Science Foundation of China (60403027)
文摘Authorization management is important precondition and foundation for coordinating and resource sharing in open networks. Recently, authorization based on trust is widely used whereby access rights to shared resource are granted on the basis of their trust relation in distributed environment. Nevertheless, dynamic change of the status of credential and chain of trust induces to uncertainty of trust relation. Considering uncertainty of authorization and analyzing deficiency of authorization model only based on trust, we proposes joint trust-risk evaluation and build the model based on fuzzy set theory, and make use of the membership grade of fuzzy set to express joint trust-risk relation. Finally, derivation principle and constraint principle of joint trust-risk relationships are presented. The authorization management model is defined based on joint trust-risk evaluation, proof of compliance and separation of duty are analyzed. The proposed model depicts not only trust relationship between principals, but also security problem of authorization.
文摘A workflow authorization model based on credentials was proposesed. It can nicely satisfy the features that workflows in actual application should satisfying. This model uses access control list based on task state which nicely ensure synchronizing authorization flow with workflow; specifies authorization policy not only based on user identifiers but also based on user qualifications and characteristics; defines a set of constraint rules for a task and seek the eligible users to execute the task according to the type of each constraint rule which realize dynamic separation of duty; and realizes the access granularity of authorization ranging from objects to specific parts of objects which ensure the least privilege constraints much more better.
文摘Quantum authorization management(QAM)is the quantum scheme for privilege management infrastructure(PMI)problem.Privilege management(authorization management)includes authentication and authorization.Authentication is to verify a user’s identity.Authorization is the process of verifying that a authenticated user has the authority to perform a operation,which is more fine-grained.In most classical schemes,the authority management center(AMC)manages the resources permissions for all network nodes within the jurisdiction.However,the existence of AMC may be the weakest link of the whole scheme.In this paper,a protocol for QAM without AMC is proposed based on entanglement swapping.In this protocol,Bob(the owner of resources)authenticates the legality of Alice(the user)and then shares the right key for the resources with Alice.Compared with the other existed QAM protocols,this protocol not only implements authentication,but also authorizes the user permissions to access certain resources or carry out certain actions.The authority division is extended to fin-grained rights division.The security is analyzed from the four aspects:the outsider’s attack,the user’s attack,authentication and comparison with the other two QAM protocols.
文摘Due to the mobility of users in an organization,inclusion of dynamic attributes such as time and location becomes the major challenge in Ciphertext-Policy Attribute-Based Encryption(CP-ABE).By considering this challenge;we focus to present dynamic time and location information in CP-ABE with mul-ti-authorization.Atfirst,along with the set of attributes of the users,their corre-sponding location is also embedded.Geohash is used to encode the latitude and longitude of the user’s position.Then,decrypt time period and access time period of users are defined using the new time tree(NTT)structure.The NTT sets the encrypted duration of the encrypted data and the valid access time of the private key on the data user’s private key.Besides,single authorization of attribute authority(AA)is extended as multi authorization for enhancing the effectiveness of key generation.Simulation results depict that the proposed CP-ABE achieves better encryption time,decryption time,security level and memory usage.Namely,encryption time and decryption time of the proposed CP-ABE are reduced to 19%and 16%than that of existing CP-ABE scheme.
