Climate change threatens cocoa quality, raising concerns regarding sustainable premium cocoa production. Evaluating the effectiveness of certification standards is imperative to address this concern effectively. A mul...Climate change threatens cocoa quality, raising concerns regarding sustainable premium cocoa production. Evaluating the effectiveness of certification standards is imperative to address this concern effectively. A multi-stage method was employed for a systematic review of 39 peer-reviewed articles to highlight the impacts of climate change on the biophysical environment of cocoa and its implications for adapting Geographical Indications (GIs). Additionally, a comprehensive review was conducted on climate-relevant standards of certificates in Ecuador, Indonesia, and Ghana. The findings of this study provide practical insights into possible difficulties that cocoa-producing countries may encounter in maintaining the distinctive flavours and quality trademarks of cocoa in the face of changing climate. Moreover, the findings emphasize the need for producer countries to prioritize viable adaptation and product differentiation strategies that meet sustainable marketing standards to protect GIs or place-based intellectual property. Furthermore, the findings indicate certificates require effective multi-level climate change management and environmental-social-governance principles that promote scientifically proven mitigation strategies, such as increasing soil organic carbon, zero deforestation, and reducing emissions while striving to leverage local adaptation policies to reduce location-specific vulnerability. Finally, certificates can accelerate the expansion, intensification, and redistribution of sustainable production for gains that outweigh the inconveniences caused by climate change.展开更多
The low-intensity attack flows used by Crossfire attacks are hard to distinguish from legitimate flows.Traditional methods to identify the malicious flows in Crossfire attacks are rerouting,which is based on statistic...The low-intensity attack flows used by Crossfire attacks are hard to distinguish from legitimate flows.Traditional methods to identify the malicious flows in Crossfire attacks are rerouting,which is based on statistics.In these existing mechanisms,the identification of malicious flows depends on the IP address.However,the IP address is easy to be changed by attacks.Comparedwith the IP address,the certificate ismore challenging to be tampered with or forged.Moreover,the traffic trend in the network is towards encryption.The certificates are popularly utilized by IoT devices for authentication in encryption protocols.DTLShps proposed a new way to verify certificates for resource-constrained IoT devices by using the SDN controller.Based on DTLShps,the SDN controller can collect statistics on certificates.In this paper,we proposeCertrust,a framework based on the trust of certificates,tomitigate the Crossfire attack by using SDN for IoT.Our goal is threefold.First,the trust model is built based on the Bayesian trust system with the statistics on the participation of certificates in each Crossfire attack.Moreover,the forgetting curve is utilized instead of the traditional decay method in the Bayesian trust system for achieving a moderate decay rate.Second,for detecting the Crossfire attack accurately,a method based on graph connectivity is proposed.Third,several trust-based routing principles are proposed tomitigate the Crossfire attack.These principles can also encourage users to use certificates in communication.The performance evaluation shows that Certrust is more effective in mitigating the Crossfire attack than the traditional rerouting schemes.Moreover,our trust model has a more appropriate decay rate than the traditional methods.展开更多
A vector space secret sharing scheme based on certificates is proposed in this paper. The difficulties of solving discrete logarithm assure confidential information's security, and the use of each participant's cert...A vector space secret sharing scheme based on certificates is proposed in this paper. The difficulties of solving discrete logarithm assure confidential information's security, and the use of each participant's certificate makes the dealer have no need to transfer secret information to the participants. The proposed scheme is dynamic. It can effectively check cheaters and does not have secure channel requirements.展开更多
In the proposed photo certificate, the principal component is the image, for example, the user's photo. User-related fields, such as the subject's name, the issuer's name, and the expiration period, which are meani...In the proposed photo certificate, the principal component is the image, for example, the user's photo. User-related fields, such as the subject's name, the issuer's name, and the expiration period, which are meaningful to users, are embedded into the surface of the photo by using a visible watermark algorithm, so that the reader can capture this information without the requirement for special software. The remaining fields in the certificate are embedded into a marked photo. Later, the whole photo certificate is eryptographically signed by certification authority (CA) private key to guarantee the integrity of our photo certificate. By such arrangement, the eertificate's verification is divided into two layers. The first layer is human visual system oriented and the second layer is the software-oriented. User can determine whether the user's photo and its subject's name are consistent and cheek whether the expired period is valid first. The second layer's verification is lunched only when the first layer's verification is passed. To sum up, the proposed photo certificate not only inherits the functions of a traditional certificate, but also provides a friendlier operational environment of X.509 certificate.展开更多
The construction of a food certification system plays a vital role in upgrading export quality, which previous studies have largely overlooked. We match China's industry-level data of Green Food Certification with...The construction of a food certification system plays a vital role in upgrading export quality, which previous studies have largely overlooked. We match China's industry-level data of Green Food Certification with its HS6-digit export data of agri-food products to quantify the impact of Green Food Certification on export quality. We identify the significant and positive effect of Green Food Certification on export quality. The 2SLS estimation based on instrumental variables and a range of robustness checks confirm the validity and robustness of the benchmark conclusions. Further analysis discloses that Green Food Certification improves export quality by raising agricultural production efficiency and brand premiums. Heterogeneity analysis shows that the effect of Green Food Certification varies across regions, notably improving the quality of agri-food products exported to developed regions and regions with high levels of import supervision. Furthermore, among various product types, Green Food Certification significantly improves the export quality of primary products and products vulnerable to non-tariff measures. The above findings could guide the future development of agri-food quality certification systems, potentially leading to a transformation and promotion of the agri-food trade.展开更多
Acoustic models of railway vehicles in standstill and pass-by conditions can be used as part of a virtual certification process for new trains.For each piece of auxiliary equipment,the sound power measured on a test b...Acoustic models of railway vehicles in standstill and pass-by conditions can be used as part of a virtual certification process for new trains.For each piece of auxiliary equipment,the sound power measured on a test bench is combined with meas-ured or predicted transfer functions.It is important,however,to allow for installation effects due to shielding by fairings or the train body.In the current work,fast-running analytical models are developed to determine these installation effects.The model for roof-mounted sources takes account of diffraction at the corner of the train body or fairing,using a barrier model.For equipment mounted under the train,the acoustic propagation from the sides of the source is based on free-field Green’s functions.The bottom surfaces are assumed to radiate initially into a cavity under the train,which is modelled with a simple diffuse field approach.The sound emitted from the gaps at the side of the cavity is then assumed to propagate to the receivers according to free-field Green’s functions.Results show good agreement with a 2.5D boundary element model and with measurements.Modelling uncertainty and parametric uncertainty are evaluated.The largest variability occurs due to the height and impedance of the ground,especially for a low receiver.This leads to standard deviations of up to 4 dB at low frequencies.For the roof-mounted sources,uncertainty over the location of the corner used in the equivalent barrier model can also lead to large standard deviations.展开更多
The traditional air traffic control information sharing data has weak security characteristics of personal privacy data and poor effect,which is easy to leads to the problem that the data is usurped.Starting from the ...The traditional air traffic control information sharing data has weak security characteristics of personal privacy data and poor effect,which is easy to leads to the problem that the data is usurped.Starting from the application of the ATC(automatic train control)network,this paper focuses on the zero trust and zero trust access strategy and the tamper-proof method of information-sharing network data.Through the improvement of ATC’s zero trust physical layer authentication and network data distributed feature differentiation calculation,this paper reconstructs the personal privacy scope authentication structure and designs a tamper-proof method of ATC’s information sharing on the Internet.From the single management authority to the unified management of data units,the systematic algorithm improvement of shared network data tamper prevention method is realized,and RDTP(Reliable Data Transfer Protocol)is selected in the network data of information sharing resources to realize the effectiveness of tamper prevention of air traffic control data during transmission.The results show that this method can reasonably avoid the tampering of information sharing on the Internet,maintain the security factors of air traffic control information sharing on the Internet,and the Central Processing Unit(CPU)utilization rate is only 4.64%,which effectively increases the performance of air traffic control data comprehensive security protection system.展开更多
This paper introduces Certis, a powerful framework that addresses the challenges of cloud asset tracking, management, and threat detection in modern cybersecurity landscapes. It enhances asset identification and anoma...This paper introduces Certis, a powerful framework that addresses the challenges of cloud asset tracking, management, and threat detection in modern cybersecurity landscapes. It enhances asset identification and anomaly detection through SSL certificate parsing, cloud service provider integration, and advanced fingerprinting techniques like JARM at the application layer. Current work will focus on cross-layer malicious behavior identification to further enhance its capabilities, including minimizing false positives through AI-based learning techniques. Certis promises to offer a powerful solution for organizations seeking proactive cybersecurity defenses in the face of evolving threats.展开更多
With the rapid development of information technology,the demand for talents in the field of software engineering is growing.In order to cultivate high-quality software engineering talents who meet the market demand,un...With the rapid development of information technology,the demand for talents in the field of software engineering is growing.In order to cultivate high-quality software engineering talents who meet the market demand,universities have continuously carried out the construction of software engineering majors.Accreditation Board for Engineering and Technology(ABET)certification,as an internationally recognized higher education quality assurance system,provides important reference and guidance for the construction of software engineering majors.Guided by student learning outcomes and core competencies,combined with the characteristics of software engineering talent cultivation,the innovation of talent cultivation mode takes industry-education integration and school-enterprise cooperation as the main development paths and explores comprehensive reform of the major in terms of professional positioning and goals,curriculum system,teaching conditions,and teachers.This comprehensive reform model has effectively promoted the development of major construction and improved the quality of talent cultivation.展开更多
This article explores the development of the Internet of Things(IoT)application technology course in higher vocational colleges under the background of“post,course,competition,certificate.”It first emphasizes the im...This article explores the development of the Internet of Things(IoT)application technology course in higher vocational colleges under the background of“post,course,competition,certificate.”It first emphasizes the importance of IoT talent training and course construction in higher vocational colleges and deeply analyzes the core concept of“post,course,competition,certificate”integration.In view of the problems faced in the course construction of IoT application technology in higher vocational colleges and the practical experience of Tianjin Vocational College of Mechanics and Electricity,the implementation strategy of the course construction of IoT application technology in higher vocational colleges is elaborated in detail based on the integrated concept of“post,course,competition,certificate.”展开更多
The core education function of higher vocational colleges is to train technical talents with high quality,so as to meet the needs of talents in the development stage of our society.Under the guidance of talent trainin...The core education function of higher vocational colleges is to train technical talents with high quality,so as to meet the needs of talents in the development stage of our society.Under the guidance of talent training,higher vocational colleges need to pay attention to establishing an all-round and three-dimensional education model,and promote innovation of higher vocational education on the basis of this.It is also a way to promote the innovation of higher vocational education to vigorously promote the construction of“post,course,competition,certificate”mode in the construction of education mode.Through the construction of“post,course,competition,certificate”mode,the education mode of higher vocational colleges is gradually improved,so as to strengthen the effectiveness of talent training in higher vocational colleges.Therefore,in this paper,the author puts forward some suggestions to promote the construction of the integrated education mode of the electronic information engineering technology major in higher vocational colleges,so as to help improve the talent training level of higher vocational colleges.展开更多
Renewable portfolio standards(RPS)are important guarantees to promote renewable energy(RE)consumption.The tradable green certificate(TGC)trading mechanism is a supporting mechanism of RPS,but the rate of TGC trading i...Renewable portfolio standards(RPS)are important guarantees to promote renewable energy(RE)consumption.The tradable green certificate(TGC)trading mechanism is a supporting mechanism of RPS,but the rate of TGC trading is low and there is a double-metering problem of RE consumption.With the introduction of new policies in China,we innovatively take the electricity-selling side as the subject of RE consumption responsibility and biomass-based electricity-generation(BEG)projects are considered to participate in TGC trading.To explore the interaction between the TGC market and the electricity market,this paper sets up a day-ahead spot market-trading structure combining both markets under RPS and establishes a market equilibrium model.The established model is solved and validated based on the particle swarm optimization algorithm and the profits of each market player under different influencing factors are analysed.The main conclusions are as follows.(i)The established market structure and model effectively solve the double-metering problem of RE consumption,making the TGC turnover rate reach 82.97%,greatly improving the market efficiency.(ii)Increased demand for TGC will increase demand for RE electricity.The participation of BEG projects in the TGC market can effectively improve the profit of biomass-based electricity producers(BEPs),reduce the burden of government financial subsidies and will not affect the consumption of wind-based electricity and photovoltaic-based electricity.This will help promote the rapid development of China’s RE,especially the BEG industry.(iii)Among the influencing factors,the increase in renewable-energy consumption responsibility weight and the decrease in electricity-generation cost can increase the profit of BEPs.The decline in TGC price and subsidy price will reduce the profit of BEPs.Finally,we put forward policy recommendations for China’s RPS and TGC trading mechanism.This study can provide a reference for the construction of China’s TGC market and electricity market and the development of RE.展开更多
Aiming at the requirement of anonymous supervision of digital certificates in blockchain public key infrastructure(PKI),this paper proposes a ring signature with multiple indirect verifications(RS-MIV).This mechanism ...Aiming at the requirement of anonymous supervision of digital certificates in blockchain public key infrastructure(PKI),this paper proposes a ring signature with multiple indirect verifications(RS-MIV).This mechanism can ensure multiple and indirect verification of certificate signer identity while preserving its anonymity.On this basis,a supervisable anonymous management scheme was designed based on smart contracts,which realizes the anonymity of certificate authority nodes,the anonymous issuance of digital certificates,the anonymous verification of digital certificates,and the traceability of illegal certificate issuers in the blockchain PKI.It is proved that the scheme can guarantee the anonymity and traceability of the certificate issuer’s identity at an acceptable cost.展开更多
The cooperative model of a multi-subject Regional Integrated Energy System(RIES)is no longer limited to the trading of traditional energy,but the trading of new energy derivatives such as Green Certificates(GC),Servic...The cooperative model of a multi-subject Regional Integrated Energy System(RIES)is no longer limited to the trading of traditional energy,but the trading of new energy derivatives such as Green Certificates(GC),Service Power(SP),and CO_(2) will be more involved in the energy allocation of the cooperative model.This study was conducted for the multi-entity RIES cooperative model considering the trading of electronics,GC,SP,and CO_(2).First,a cooperative framework including wind-photovoltaic generation system(WG),combined heat and power system(CHP),and power-carbon-hydrogen load(PCH)is proposed,and the mechanism of energy derivatives trading is also analyzed.Then,the sub-models of each agent in the cooperative model are established separately so that WG has the capability of GC generation,CHP has the capability of GC and CO_(2) absorption,and PCH can realize the effective utilization of CO_(2).Then,the WG–CHP–PCH cooperative model is established and equated into two sub-problems of cooperative benefit maximization and transaction payment negotiation,which are solved in a distributed manner by the alternating directed multiplier method(ADMM).Finally,the effectiveness of the proposed cooperative model and distributed solution is verified by simulation.The simulation results show that the WG–CHP–PCH cooperative model can substantially improve the operational efficiency of each agent and realize the efficient redistribution of energy and its derivatives.In addition,the dynamic parameter adjustment algorithm(DP)is further applied in the solving process to improve its convergence speed.By updating the step size during each iteration,the computational cost,the number of iterations,and the apparent oscillations are reduced,and the convergence performance of the algorithm is improved.展开更多
Cooperation in energy systems is no longer limited to the distribution of electricity,and more attention is paid to the trading of green certificates(GCs).This paper proposed a cooperative method for photovoltaic(PV)a...Cooperation in energy systems is no longer limited to the distribution of electricity,and more attention is paid to the trading of green certificates(GCs).This paper proposed a cooperative method for photovoltaic(PV)and electric-to-hydrogen(EH)trading,including GC trading under risk management.First,a novel PV and EH model is established and the cooperation mechanism is analyzed.Meanwhile,PV and EH models were risk-controlled using the conditional value at risk to reduce the impact of the uncertainty of PV electricity and EH loads.Then,the PV-EH cooperative model was established based on cooperative game theory;this was then divided into two subproblems of“cooperative benefit maximization”and“transaction payment negotiation,”and the above two subproblems were solved distributively by alternating direction multiplier method(ADMM).Only energy transactions and price negotiations were conducted between the PV and EH,which can protect the privacy and confidentiality of each entity.Finally,the effectiveness of the cooperation model was verified using a practical engineering case.The simulation results show that the cooperation of the PV-EH can significantly improve the operational efficiency of each entity and the overall efficiency of the cooperation and realize the efficient redistribution of electricity and GC.展开更多
With the increasing proportion of renewable energy in the power market,the demands on government financial subsidies are gradually increasing.Thus,a joint green certificate-carbon emission right-electricity multi-mark...With the increasing proportion of renewable energy in the power market,the demands on government financial subsidies are gradually increasing.Thus,a joint green certificate-carbon emission right-electricity multi-market trading process is proposed to study the market-based strategy for renewable energy.Considering the commodity characteristics of green certificates and carbon emission rights,the dynamic cost models of green certificates and carbon rights are constructed based on the Rubinstein game and ladder pricing models.Furthermore,considering the irrational bidding behavior of energy suppliers in the actual electricity market,an evolutionary game based multi-market bidding optimization model is presented.Subsequently,it is solved using a composite differential evolutionary algorithm.Finally,the case study results reveal that the proposed model can increase profits and the consumption rate of renewable energy and reduce carbon emission.展开更多
This paper emphatically sums up the problems existing in the implementation of"1+X"certificate system by taking horticulture major in higher vocational colleges as an example.From the point of view of the im...This paper emphatically sums up the problems existing in the implementation of"1+X"certificate system by taking horticulture major in higher vocational colleges as an example.From the point of view of the improvement of"1+X"certificate system,the reform of talent training program,the improvement of teachers ability and summing up experience,this paper puts forward the updated working mode and ideas to provide strategies for accelerating the development of vocational education in southern Xinjiang.展开更多
The trusted sharing of Electronic Health Records(EHRs)can realize the efficient use of medical data resources.Generally speaking,EHRs are widely used in blockchain-based medical data platforms.EHRs are valuable privat...The trusted sharing of Electronic Health Records(EHRs)can realize the efficient use of medical data resources.Generally speaking,EHRs are widely used in blockchain-based medical data platforms.EHRs are valuable private assets of patients,and the ownership belongs to patients.While recent research has shown that patients can freely and effectively delete the EHRs stored in hospitals,it does not address the challenge of record sharing when patients revisit doctors.In order to solve this problem,this paper proposes a deletion and recovery scheme of EHRs based on Medical Certificate Blockchain.This paper uses cross-chain technology to connect the Medical Certificate Blockchain and the Hospital Blockchain to real-ize the recovery of deleted EHRs.At the same time,this paper uses the Medical Certificate Blockchain and the InterPlanetary File System(IPFS)to store Personal Health Records,which are generated by patients visiting different medical institutions.In addition,this paper also combines digital watermarking technology to ensure the authenticity of the restored electronic medical records.Under the combined effect of blockchain technology and digital watermarking,our proposal will not be affected by any other rights throughout the process.System analysis and security analysis illustrate the completeness and feasibility of the scheme.展开更多
Smart parks serve as integral components of smart cities,where they play a pivotal role in the process of urban modernization.The demand for cross-domain cooperation among smart devices from various parks has witnesse...Smart parks serve as integral components of smart cities,where they play a pivotal role in the process of urban modernization.The demand for cross-domain cooperation among smart devices from various parks has witnessed a significant increase.To ensure secure communication,device identities must undergo authentication.The existing cross-domain authentication schemes face issues such as complex authentication paths and high certificate management costs for devices,making it impractical for resource-constrained devices.This paper proposes a blockchain-based lightweight and efficient cross-domain authentication protocol for smart parks,which simplifies the authentication interaction and requires every device to maintain only one certificate.To enhance cross-domain cooperation flexibility,a comprehensive certificate revocation mechanism is presented,significantly reducing certificate management costs while ensuring efficient and secure identity authentication.When a park needs to revoke access permissions of several cooperative partners,the revocation of numerous cross-domain certificates can be accomplished with a single blockchain write operation.The security analysis and experimental results demonstrate the security and effectiveness of our scheme.展开更多
文摘Climate change threatens cocoa quality, raising concerns regarding sustainable premium cocoa production. Evaluating the effectiveness of certification standards is imperative to address this concern effectively. A multi-stage method was employed for a systematic review of 39 peer-reviewed articles to highlight the impacts of climate change on the biophysical environment of cocoa and its implications for adapting Geographical Indications (GIs). Additionally, a comprehensive review was conducted on climate-relevant standards of certificates in Ecuador, Indonesia, and Ghana. The findings of this study provide practical insights into possible difficulties that cocoa-producing countries may encounter in maintaining the distinctive flavours and quality trademarks of cocoa in the face of changing climate. Moreover, the findings emphasize the need for producer countries to prioritize viable adaptation and product differentiation strategies that meet sustainable marketing standards to protect GIs or place-based intellectual property. Furthermore, the findings indicate certificates require effective multi-level climate change management and environmental-social-governance principles that promote scientifically proven mitigation strategies, such as increasing soil organic carbon, zero deforestation, and reducing emissions while striving to leverage local adaptation policies to reduce location-specific vulnerability. Finally, certificates can accelerate the expansion, intensification, and redistribution of sustainable production for gains that outweigh the inconveniences caused by climate change.
基金supported by Joint Funds of the National Natural Science Foundation of China and Xinjiang under Project U1603261.
文摘The low-intensity attack flows used by Crossfire attacks are hard to distinguish from legitimate flows.Traditional methods to identify the malicious flows in Crossfire attacks are rerouting,which is based on statistics.In these existing mechanisms,the identification of malicious flows depends on the IP address.However,the IP address is easy to be changed by attacks.Comparedwith the IP address,the certificate ismore challenging to be tampered with or forged.Moreover,the traffic trend in the network is towards encryption.The certificates are popularly utilized by IoT devices for authentication in encryption protocols.DTLShps proposed a new way to verify certificates for resource-constrained IoT devices by using the SDN controller.Based on DTLShps,the SDN controller can collect statistics on certificates.In this paper,we proposeCertrust,a framework based on the trust of certificates,tomitigate the Crossfire attack by using SDN for IoT.Our goal is threefold.First,the trust model is built based on the Bayesian trust system with the statistics on the participation of certificates in each Crossfire attack.Moreover,the forgetting curve is utilized instead of the traditional decay method in the Bayesian trust system for achieving a moderate decay rate.Second,for detecting the Crossfire attack accurately,a method based on graph connectivity is proposed.Third,several trust-based routing principles are proposed tomitigate the Crossfire attack.These principles can also encourage users to use certificates in communication.The performance evaluation shows that Certrust is more effective in mitigating the Crossfire attack than the traditional rerouting schemes.Moreover,our trust model has a more appropriate decay rate than the traditional methods.
基金Supported by the National Natural Science Foun-dation of China(60573129) the Opening Foundation of State Key La-boratory of Information Security and the Opening Foundation of KeyLaboratory of Computer Network and Information Security, Ministryof Education of PRC.
文摘A vector space secret sharing scheme based on certificates is proposed in this paper. The difficulties of solving discrete logarithm assure confidential information's security, and the use of each participant's certificate makes the dealer have no need to transfer secret information to the participants. The proposed scheme is dynamic. It can effectively check cheaters and does not have secure channel requirements.
文摘In the proposed photo certificate, the principal component is the image, for example, the user's photo. User-related fields, such as the subject's name, the issuer's name, and the expiration period, which are meaningful to users, are embedded into the surface of the photo by using a visible watermark algorithm, so that the reader can capture this information without the requirement for special software. The remaining fields in the certificate are embedded into a marked photo. Later, the whole photo certificate is eryptographically signed by certification authority (CA) private key to guarantee the integrity of our photo certificate. By such arrangement, the eertificate's verification is divided into two layers. The first layer is human visual system oriented and the second layer is the software-oriented. User can determine whether the user's photo and its subject's name are consistent and cheek whether the expired period is valid first. The second layer's verification is lunched only when the first layer's verification is passed. To sum up, the proposed photo certificate not only inherits the functions of a traditional certificate, but also provides a friendlier operational environment of X.509 certificate.
基金supported by the National Natural Science Foundation of China(72061147002)the National Social Science Foundation of China(18ZDA074)。
文摘The construction of a food certification system plays a vital role in upgrading export quality, which previous studies have largely overlooked. We match China's industry-level data of Green Food Certification with its HS6-digit export data of agri-food products to quantify the impact of Green Food Certification on export quality. We identify the significant and positive effect of Green Food Certification on export quality. The 2SLS estimation based on instrumental variables and a range of robustness checks confirm the validity and robustness of the benchmark conclusions. Further analysis discloses that Green Food Certification improves export quality by raising agricultural production efficiency and brand premiums. Heterogeneity analysis shows that the effect of Green Food Certification varies across regions, notably improving the quality of agri-food products exported to developed regions and regions with high levels of import supervision. Furthermore, among various product types, Green Food Certification significantly improves the export quality of primary products and products vulnerable to non-tariff measures. The above findings could guide the future development of agri-food quality certification systems, potentially leading to a transformation and promotion of the agri-food trade.
基金The work described here has been supported by the TRANSIT project(funded by EU Horizon 2020 and the Europe’s Rail Joint Undertaking under grant agreement 881771).
文摘Acoustic models of railway vehicles in standstill and pass-by conditions can be used as part of a virtual certification process for new trains.For each piece of auxiliary equipment,the sound power measured on a test bench is combined with meas-ured or predicted transfer functions.It is important,however,to allow for installation effects due to shielding by fairings or the train body.In the current work,fast-running analytical models are developed to determine these installation effects.The model for roof-mounted sources takes account of diffraction at the corner of the train body or fairing,using a barrier model.For equipment mounted under the train,the acoustic propagation from the sides of the source is based on free-field Green’s functions.The bottom surfaces are assumed to radiate initially into a cavity under the train,which is modelled with a simple diffuse field approach.The sound emitted from the gaps at the side of the cavity is then assumed to propagate to the receivers according to free-field Green’s functions.Results show good agreement with a 2.5D boundary element model and with measurements.Modelling uncertainty and parametric uncertainty are evaluated.The largest variability occurs due to the height and impedance of the ground,especially for a low receiver.This leads to standard deviations of up to 4 dB at low frequencies.For the roof-mounted sources,uncertainty over the location of the corner used in the equivalent barrier model can also lead to large standard deviations.
基金This work was supported by National Natural Science Foundation of China(U2133208,U20A20161).
文摘The traditional air traffic control information sharing data has weak security characteristics of personal privacy data and poor effect,which is easy to leads to the problem that the data is usurped.Starting from the application of the ATC(automatic train control)network,this paper focuses on the zero trust and zero trust access strategy and the tamper-proof method of information-sharing network data.Through the improvement of ATC’s zero trust physical layer authentication and network data distributed feature differentiation calculation,this paper reconstructs the personal privacy scope authentication structure and designs a tamper-proof method of ATC’s information sharing on the Internet.From the single management authority to the unified management of data units,the systematic algorithm improvement of shared network data tamper prevention method is realized,and RDTP(Reliable Data Transfer Protocol)is selected in the network data of information sharing resources to realize the effectiveness of tamper prevention of air traffic control data during transmission.The results show that this method can reasonably avoid the tampering of information sharing on the Internet,maintain the security factors of air traffic control information sharing on the Internet,and the Central Processing Unit(CPU)utilization rate is only 4.64%,which effectively increases the performance of air traffic control data comprehensive security protection system.
文摘This paper introduces Certis, a powerful framework that addresses the challenges of cloud asset tracking, management, and threat detection in modern cybersecurity landscapes. It enhances asset identification and anomaly detection through SSL certificate parsing, cloud service provider integration, and advanced fingerprinting techniques like JARM at the application layer. Current work will focus on cross-layer malicious behavior identification to further enhance its capabilities, including minimizing false positives through AI-based learning techniques. Certis promises to offer a powerful solution for organizations seeking proactive cybersecurity defenses in the face of evolving threats.
基金Digital Twin and Acoustic Perception Research Team(2021XJTD06)。
文摘With the rapid development of information technology,the demand for talents in the field of software engineering is growing.In order to cultivate high-quality software engineering talents who meet the market demand,universities have continuously carried out the construction of software engineering majors.Accreditation Board for Engineering and Technology(ABET)certification,as an internationally recognized higher education quality assurance system,provides important reference and guidance for the construction of software engineering majors.Guided by student learning outcomes and core competencies,combined with the characteristics of software engineering talent cultivation,the innovation of talent cultivation mode takes industry-education integration and school-enterprise cooperation as the main development paths and explores comprehensive reform of the major in terms of professional positioning and goals,curriculum system,teaching conditions,and teachers.This comprehensive reform model has effectively promoted the development of major construction and improved the quality of talent cultivation.
基金2021 Tianjin Educational Science Planning Project“Research and Practice of Talent Cultivation Mode for IoT Majors in Higher Vocational Colleges under the Guidance of the‘1+X’Certificate System”(CJE210237)。
文摘This article explores the development of the Internet of Things(IoT)application technology course in higher vocational colleges under the background of“post,course,competition,certificate.”It first emphasizes the importance of IoT talent training and course construction in higher vocational colleges and deeply analyzes the core concept of“post,course,competition,certificate”integration.In view of the problems faced in the course construction of IoT application technology in higher vocational colleges and the practical experience of Tianjin Vocational College of Mechanics and Electricity,the implementation strategy of the course construction of IoT application technology in higher vocational colleges is elaborated in detail based on the integrated concept of“post,course,competition,certificate.”
文摘The core education function of higher vocational colleges is to train technical talents with high quality,so as to meet the needs of talents in the development stage of our society.Under the guidance of talent training,higher vocational colleges need to pay attention to establishing an all-round and three-dimensional education model,and promote innovation of higher vocational education on the basis of this.It is also a way to promote the innovation of higher vocational education to vigorously promote the construction of“post,course,competition,certificate”mode in the construction of education mode.Through the construction of“post,course,competition,certificate”mode,the education mode of higher vocational colleges is gradually improved,so as to strengthen the effectiveness of talent training in higher vocational colleges.Therefore,in this paper,the author puts forward some suggestions to promote the construction of the integrated education mode of the electronic information engineering technology major in higher vocational colleges,so as to help improve the talent training level of higher vocational colleges.
基金This research did not receive any grant from funding agencies in the public,commercial or not-for-profit sectors。
文摘Renewable portfolio standards(RPS)are important guarantees to promote renewable energy(RE)consumption.The tradable green certificate(TGC)trading mechanism is a supporting mechanism of RPS,but the rate of TGC trading is low and there is a double-metering problem of RE consumption.With the introduction of new policies in China,we innovatively take the electricity-selling side as the subject of RE consumption responsibility and biomass-based electricity-generation(BEG)projects are considered to participate in TGC trading.To explore the interaction between the TGC market and the electricity market,this paper sets up a day-ahead spot market-trading structure combining both markets under RPS and establishes a market equilibrium model.The established model is solved and validated based on the particle swarm optimization algorithm and the profits of each market player under different influencing factors are analysed.The main conclusions are as follows.(i)The established market structure and model effectively solve the double-metering problem of RE consumption,making the TGC turnover rate reach 82.97%,greatly improving the market efficiency.(ii)Increased demand for TGC will increase demand for RE electricity.The participation of BEG projects in the TGC market can effectively improve the profit of biomass-based electricity producers(BEPs),reduce the burden of government financial subsidies and will not affect the consumption of wind-based electricity and photovoltaic-based electricity.This will help promote the rapid development of China’s RE,especially the BEG industry.(iii)Among the influencing factors,the increase in renewable-energy consumption responsibility weight and the decrease in electricity-generation cost can increase the profit of BEPs.The decline in TGC price and subsidy price will reduce the profit of BEPs.Finally,we put forward policy recommendations for China’s RPS and TGC trading mechanism.This study can provide a reference for the construction of China’s TGC market and electricity market and the development of RE.
基金This work was supported in part by the National Key Research and Development Program of China under Grant 2018YFB0803603 and Grant 2016YFB0501901in part by the National Natural Science Foundation of China under Grant 61502531,Grant 61702550,and Grant 61802436.
文摘Aiming at the requirement of anonymous supervision of digital certificates in blockchain public key infrastructure(PKI),this paper proposes a ring signature with multiple indirect verifications(RS-MIV).This mechanism can ensure multiple and indirect verification of certificate signer identity while preserving its anonymity.On this basis,a supervisable anonymous management scheme was designed based on smart contracts,which realizes the anonymity of certificate authority nodes,the anonymous issuance of digital certificates,the anonymous verification of digital certificates,and the traceability of illegal certificate issuers in the blockchain PKI.It is proved that the scheme can guarantee the anonymity and traceability of the certificate issuer’s identity at an acceptable cost.
基金supported in part by the Science and Technology Project of State Grid Corporation of China under Grant(No.52272220002T)in part by the project supported by Sichuan Provincial key research and development program of China(No.2022YFG0123)in part by Central Government Funds for Guiding Local Scientific and Technological Development of China(No.2021ZYD0042).
文摘The cooperative model of a multi-subject Regional Integrated Energy System(RIES)is no longer limited to the trading of traditional energy,but the trading of new energy derivatives such as Green Certificates(GC),Service Power(SP),and CO_(2) will be more involved in the energy allocation of the cooperative model.This study was conducted for the multi-entity RIES cooperative model considering the trading of electronics,GC,SP,and CO_(2).First,a cooperative framework including wind-photovoltaic generation system(WG),combined heat and power system(CHP),and power-carbon-hydrogen load(PCH)is proposed,and the mechanism of energy derivatives trading is also analyzed.Then,the sub-models of each agent in the cooperative model are established separately so that WG has the capability of GC generation,CHP has the capability of GC and CO_(2) absorption,and PCH can realize the effective utilization of CO_(2).Then,the WG–CHP–PCH cooperative model is established and equated into two sub-problems of cooperative benefit maximization and transaction payment negotiation,which are solved in a distributed manner by the alternating directed multiplier method(ADMM).Finally,the effectiveness of the proposed cooperative model and distributed solution is verified by simulation.The simulation results show that the WG–CHP–PCH cooperative model can substantially improve the operational efficiency of each agent and realize the efficient redistribution of energy and its derivatives.In addition,the dynamic parameter adjustment algorithm(DP)is further applied in the solving process to improve its convergence speed.By updating the step size during each iteration,the computational cost,the number of iterations,and the apparent oscillations are reduced,and the convergence performance of the algorithm is improved.
基金supported in part by the National Natural Science Foundation of China(No.5197707).
文摘Cooperation in energy systems is no longer limited to the distribution of electricity,and more attention is paid to the trading of green certificates(GCs).This paper proposed a cooperative method for photovoltaic(PV)and electric-to-hydrogen(EH)trading,including GC trading under risk management.First,a novel PV and EH model is established and the cooperation mechanism is analyzed.Meanwhile,PV and EH models were risk-controlled using the conditional value at risk to reduce the impact of the uncertainty of PV electricity and EH loads.Then,the PV-EH cooperative model was established based on cooperative game theory;this was then divided into two subproblems of“cooperative benefit maximization”and“transaction payment negotiation,”and the above two subproblems were solved distributively by alternating direction multiplier method(ADMM).Only energy transactions and price negotiations were conducted between the PV and EH,which can protect the privacy and confidentiality of each entity.Finally,the effectiveness of the cooperation model was verified using a practical engineering case.The simulation results show that the cooperation of the PV-EH can significantly improve the operational efficiency of each entity and the overall efficiency of the cooperation and realize the efficient redistribution of electricity and GC.
基金supported by the National Key R&D Program of China(2017YFB0902200).
文摘With the increasing proportion of renewable energy in the power market,the demands on government financial subsidies are gradually increasing.Thus,a joint green certificate-carbon emission right-electricity multi-market trading process is proposed to study the market-based strategy for renewable energy.Considering the commodity characteristics of green certificates and carbon emission rights,the dynamic cost models of green certificates and carbon rights are constructed based on the Rubinstein game and ladder pricing models.Furthermore,considering the irrational bidding behavior of energy suppliers in the actual electricity market,an evolutionary game based multi-market bidding optimization model is presented.Subsequently,it is solved using a composite differential evolutionary algorithm.Finally,the case study results reveal that the proposed model can increase profits and the consumption rate of renewable energy and reduce carbon emission.
基金Supported by School-level Cultivation Project of Hetian Vocational and Technical College(HZ-2022-14)Science and Technology Research and Development Plan Project in Hetian Area(20220219).
文摘This paper emphatically sums up the problems existing in the implementation of"1+X"certificate system by taking horticulture major in higher vocational colleges as an example.From the point of view of the improvement of"1+X"certificate system,the reform of talent training program,the improvement of teachers ability and summing up experience,this paper puts forward the updated working mode and ideas to provide strategies for accelerating the development of vocational education in southern Xinjiang.
基金supported by the National Natural Science Foundation of China under grant 61972207,U1836208,U1836110,61672290the Major Program of the National Social Science Fund of China under Grant No.17ZDA092+2 种基金by the National Key R&D Program of China under grant 2018YFB1003205by the Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET)fundby the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)fund.
文摘The trusted sharing of Electronic Health Records(EHRs)can realize the efficient use of medical data resources.Generally speaking,EHRs are widely used in blockchain-based medical data platforms.EHRs are valuable private assets of patients,and the ownership belongs to patients.While recent research has shown that patients can freely and effectively delete the EHRs stored in hospitals,it does not address the challenge of record sharing when patients revisit doctors.In order to solve this problem,this paper proposes a deletion and recovery scheme of EHRs based on Medical Certificate Blockchain.This paper uses cross-chain technology to connect the Medical Certificate Blockchain and the Hospital Blockchain to real-ize the recovery of deleted EHRs.At the same time,this paper uses the Medical Certificate Blockchain and the InterPlanetary File System(IPFS)to store Personal Health Records,which are generated by patients visiting different medical institutions.In addition,this paper also combines digital watermarking technology to ensure the authenticity of the restored electronic medical records.Under the combined effect of blockchain technology and digital watermarking,our proposal will not be affected by any other rights throughout the process.System analysis and security analysis illustrate the completeness and feasibility of the scheme.
基金supported in part by the National Natural Science Foundation Project of China under Grant No.62062009the Guangxi Innovation-Driven Development Project under Grant Nos.AA17204058-17 and AA18118047-7.
文摘Smart parks serve as integral components of smart cities,where they play a pivotal role in the process of urban modernization.The demand for cross-domain cooperation among smart devices from various parks has witnessed a significant increase.To ensure secure communication,device identities must undergo authentication.The existing cross-domain authentication schemes face issues such as complex authentication paths and high certificate management costs for devices,making it impractical for resource-constrained devices.This paper proposes a blockchain-based lightweight and efficient cross-domain authentication protocol for smart parks,which simplifies the authentication interaction and requires every device to maintain only one certificate.To enhance cross-domain cooperation flexibility,a comprehensive certificate revocation mechanism is presented,significantly reducing certificate management costs while ensuring efficient and secure identity authentication.When a park needs to revoke access permissions of several cooperative partners,the revocation of numerous cross-domain certificates can be accomplished with a single blockchain write operation.The security analysis and experimental results demonstrate the security and effectiveness of our scheme.