Objective:To explore the role of specialized group management in the quality control of perioperative nursing.Methods:45 surgical nurses from our hospital were selected as the research subjects.Traditional operating r...Objective:To explore the role of specialized group management in the quality control of perioperative nursing.Methods:45 surgical nurses from our hospital were selected as the research subjects.Traditional operating room management was adopted from July 2019 to June 2020,and specialized group management was adopted from July 2020 to June 2021.The surgeon’s satisfaction,surgical nurses’core professional competence,and surgical patients’satisfaction were obtained through surveys and the results were analyzed.Results:Surgeon satisfaction before the implementation of specialized group management was significantly lower than after its implementation(P<0.05).Besides,surgical nurses’core professional competency scores before the implementation of specialized group management were significantly lower than after its implementation(P<0.05).Lastly,surgical patients’satisfaction before the implementation of specialized group management was significantly lower than after its implementation(P<0.05).Conclusion:Specialized group management helps to improve the quality of perioperative care and should be applied in clinical practice.展开更多
Objective: to sort out the clinical value of implementing quality control group management mode in emergency department nursing management, so as to provide reference and reference for gradually improving the quality ...Objective: to sort out the clinical value of implementing quality control group management mode in emergency department nursing management, so as to provide reference and reference for gradually improving the quality of emergency nursing. Methods: to sort out the nursing quality assessment results of the nursing staff in the emergency department of our hospital during the period from January 2019 to December 20, 2019, and then compare them with the nursing quality assessment results of the nursing staff after the establishment of the nursing quality control group in 2021, so as to provide reference and reference for the preparation of a scientific, standardized and efficient emergency nursing management plan, so as to continuously improve the nursing level of the undergraduate department. Results: according to the same version of the emergency nursing quality standard, the emergency nursing quality assessment was carried out in 2019 and 2021. It can be found that in 2019, the average of the assessment results was (93.23 ± 2.46) points, and the number of adverse reaction events in the undergraduate department was 10 pieces. In 2021, the average result of roast goose was (97.02 ± 1.49) points, and the number of adverse reaction events occurred in the undergraduate room was 4 pieces. The difference between the two data was prominent and there was a statistical advantage (P < 0.05). Conclusion: in the nursing management of the emergency department, the establishment of the nursing quality control team can play a positive role. It can detect the shortcomings and shortcomings of the nursing period at the first time, and analyze and rectify the root causes, so as to avoid risks, and improve the clinical nursing level and patient satisfaction.展开更多
Efficient and safe information exchange between vehicles can reduce the probability of road accidents,thereby improving the driving experience of vehicles in Vehicular Ad Hoc Networks(VANETs).This paper proposes a gro...Efficient and safe information exchange between vehicles can reduce the probability of road accidents,thereby improving the driving experience of vehicles in Vehicular Ad Hoc Networks(VANETs).This paper proposes a group management algorithm with trust and mobility evaluation to address the enormous pressure on VANETs topology caused by high-speed vehicle movement and dynamic changes in the direction of travel.This algorithm utilizes historical interactive data to mine the fusion trust between vehicles.Then,combined with fusion mobility,the selection of center members and information maintenance of group members is achieved.Furthermore,based on bilinear pairing,an encryption protocol is designed to solve the problem of key management and update when the group structure changes rapidly,ensuring the safe forwarding of messages within and between groups.Numerical analysis shows that the algorithm in the paper ensures group stability and improves performance such as average message delivery rate and interaction delay.展开更多
By introducing XOR operation and one-way function chains to group key management schemes based on the keys tree, a new group key management scheme based on the keys tree, XOR operation and one-way function chains is p...By introducing XOR operation and one-way function chains to group key management schemes based on the keys tree, a new group key management scheme based on the keys tree, XOR operation and one-way function chains is proposed. Initialization, member adding and member evicting operations are introduced. The new scheme is compared with three other group key management schemes which are based on the keys tree： SKDC, LKH, and OFF. As far as transmission, computation and storage costs are concerned, the performance of the new group key management scheme is the best. The security problem of the new scheme is analyzed. This new scheme provides backward and forward security, i.e.. newly admitted group members cannot read previous multicast messages and evicted members cannot read future multicast messages, even with collusion by many arbitrarily evicted members.展开更多
The key exposure problem is a practical threat for many security applications. In wireless sensor networks (WSNs), keys could be compromised easily due to its limited hardware protections. A secure group key managemen...The key exposure problem is a practical threat for many security applications. In wireless sensor networks (WSNs), keys could be compromised easily due to its limited hardware protections. A secure group key management scheme is responsible for secure distributing group keys among valid nodes of the group. Based on the key-insulated encryption (KIE), we propose a group key management scheme (KIE-GKMS), which integrates the pair-wise key pre-distribution for WSN. The KIE-GKMS scheme updates group keys dynamically when adding or removing nodes. Moreover, the security analysis proves that the KIE-GKMS scheme not only obtains the semantic security, but also provides the forward and backward security. Finally, the theoretical analysis shows that the KIE-GKMS scheme has constant performance on both communication and storage costs in sensor nodes.展开更多
The m ajor advantages of EBS-based key rrkanagerrent scheme are its enhanced network survivability, high dynamic performance, and better support for network expansion. But it suffers from the collusion problem, which ...The m ajor advantages of EBS-based key rrkanagerrent scheme are its enhanced network survivability, high dynamic performance, and better support for network expansion. But it suffers from the collusion problem, which means it is prone to the cooperative attack of evicted members. A novel EBS-based collusion resistant group management scheme utilizing the construction of Ciphertext-Policy Attribute-Based Encryption （CP-ABE） is proposed. The new scheme satisfies the desired security properties, such as forward secrecy, backward secrecy and collusion secrecy. Compared with existing EBS-based key rmnagement scheme, the new scheme can resolve EBS collusion problem completely. Even all evicted members work together, and share their individual piece of information, they could not access to the new group key. In addition, our scheme is more efficient in terms of conmnication and computation overhead when the group size is large. It can be well controlled even in the case of large-scale application scenarios.展开更多
Considering the special requirements of group enterprise information management software, a new method of massive software development was put forward basing on the component technology and facing the ＂assemblage＂. ...Considering the special requirements of group enterprise information management software, a new method of massive software development was put forward basing on the component technology and facing the ＂assemblage＂. It generalizes five key parts of the method system including the overall strategy, the application project method basing on the operation ＂assemblage＂, the field project method basing on component, the development method facing the component on the basis of the visible component platform, and the software development process model basing on the component ＂assemblage＂. Besides, this paper describes the process and principle of this method application with an example of the construction of a Communications Investment Group enterprise＇s management information system. The method provides a new idea for breaking away from the predicament appeared in the construction of present enterprise informatization and exploring the way of software industrialization.展开更多
Cloud data sharing service, which allows a group of people to work together to access and modify the shared data, is one of the most popular and efficient working styles in the enterprises. However, the cloud server i...Cloud data sharing service, which allows a group of people to work together to access and modify the shared data, is one of the most popular and efficient working styles in the enterprises. However, the cloud server is not completely trusted, and its security could be compromised by monetary reasons or caused by hacking and hardware errors. Therefore, despite of having advantages of scalability and flexibility, cloud storage service comes with privacy and the security concerns. A straightforward method to protect the user's privacy is to encrypt the data stored at the cloud. To enable the authenticated users to access the encrypted cloud data, a practical group key management algorithm for the cloud data sharing application is highly desired. The existing group key management mechanisms presume that the server is trusted. But, the cloud data service mode does not always meet this condition. How to manage the group keys to support the scenario of the cloud storage with a semi-trusted cloud server is still a challenging task. Moreover, the cloud storage system is a large-scale and open application, in which the user group is dynamic. To address this problem, we propose a practical group key management algorithm based on a proxy re-encryption mechanism in this paper. We use the cloud server to act as a proxy tore-encrypt the group key to allow authorized users to decrypt and get the group key by their private key. To achieve the hierarchical access control policy, our scheme enables the cloud server to convert the encrypted group key of the lower group to the upper group. The numerical analysis and experimental results further validate the high efficiency and security of the proposed scheme.展开更多
Objective: to explore the application value of group authorization management in improving nursing quality in operating room. Methods: this study was carried out from July 2019 to July 2020. 60 operating room nurses i...Objective: to explore the application value of group authorization management in improving nursing quality in operating room. Methods: this study was carried out from July 2019 to July 2020. 60 operating room nurses in our hospital were selected as observation objects, and the nurses were equally divided by blind selection method. 30 patients in the control group and 30 patients in the observation group were given conventional management and group authorization management respectively. The incidence of adverse events and skill scores of the two groups of nursing staff were observed and compared. Results: 1 nurse in the observation group had an adverse event, while 8 in the control group. The difference between the two groups was significant (P < 0.05). At the same time, combined with the evaluation of the two groups of nurses' emergency ability score, operation coordination proficiency score and specialized equipment use ability score, the observation group of nurses' skills score was better than the control group, the difference between the indicators is significant (p < 0.05). Conclusion: the implementation of group authorization management for operating room nursing staff can significantly reduce the occurrence of adverse events among nurses and improve the professional skills of nursing staff, which is of great significance to improve the quality of nursing in operating room.展开更多
Objective: to analyze the effect of quality control group management in the nursing of nail breast surgery. Methods: from December 2020 to April 2021, 98 cases of patients undergoing nail breast surgery in our hospita...Objective: to analyze the effect of quality control group management in the nursing of nail breast surgery. Methods: from December 2020 to April 2021, 98 cases of patients undergoing nail breast surgery in our hospital were selected as the observation objects of this study. The patients were randomly divided into two groups. The control group adopted routine nursing, and the observation group adopted routine nursing + quality control management. The occurrence of nursing errors and patient satisfaction were compared between the two groups. Results: the incidence of adverse events in observation group was 8.16%, which was lower than that in control group (26.52%) (P < 0.05). The satisfaction of the observation group was 93.88%, which was higher than that of the control group (80.43%) (P < 0.05). Conclusion: the intervention of quality control management on the basis of routine nursing can effectively reduce the occurrence of adverse events such as nursery-patient disputes, improve patient satisfaction, and the effect is ideal.展开更多
Intelligent transportation system （ITS） is proposed as the most effective way to improve road safety and traffic efficiency. However, the future of ITS for large scale transportation infrastructures deployment highl...Intelligent transportation system （ITS） is proposed as the most effective way to improve road safety and traffic efficiency. However, the future of ITS for large scale transportation infrastructures deployment highly depends on the security level of vehicular communication systems （VCS）. Security applications in VCS are fulfilled through secured group broadcast. Therefore, secure key management schemes are considered as a critical research topic for network security. In this paper, we propose a framework for providing secure key management within heterogeneous network. The seeurity managers （SMs） play a key role in the framework by retrieving the vehicle departnre infi^rmation, encapsulating block to transport keys and then executing rekeying to vehicles within the same security domain. The first part of this framework is a novel Group Key Management （GKM） scheme basing on leaving probability （LP） of vehicles to depart current VCS region. Vehicle＇s LP factor is introduced into GKM scheme to achieve a more effieient rekeying scheme and less rekeying costs. The second component of the framework using the blockchain concept to simplify the distributed key management in heterogeneous VCS domains. Extensive simulations and analysis are provided to show the effectiveness and effieiency of the proposed framework： Our GKM results demonstrate that probability-based BR reduees rekeying eost compared to the benchmark scheme, while the blockchain deereases the time eost of key transmission over heterogeneous net-works.展开更多
Secure group communications are restrained by the number of the group size,number of changes and their distribution,all existing works do not meet the commands of applications with large group size and high dynamic me...Secure group communications are restrained by the number of the group size,number of changes and their distribution,all existing works do not meet the commands of applications with large group size and high dynamic members.In this paper,minimum exact cover problem for group key distribution(GMECP)is presented,and a heuristic solution is testified.Then an algorithm of batch rekeying with renewing cost tending to zero is illustrated,which can process any large number of change requests with best security guaranteed.Efficiency analysis and simulation test show that the achievement can improve the efficiency of any tree-based group key management.展开更多
Group work has many advantages from language acquisition point of view. However, some teachers are unwilling to introduce group work in their own classroom because group work is very difficult to manage. The author of...Group work has many advantages from language acquisition point of view. However, some teachers are unwilling to introduce group work in their own classroom because group work is very difficult to manage. The author of this essay explores the discourse features of successful and unsuccessful group work using discourse analysis in the hope that the results of this language classroom research can help language teachers gain some insight into the use of group work and make more informed decisions about group work management.展开更多
As the major problem in multicast security, the group key management has been the focus of research But few results are satisfactory. In this paper, the problems of group key management and access control for large dy...As the major problem in multicast security, the group key management has been the focus of research But few results are satisfactory. In this paper, the problems of group key management and access control for large dynamic multicast group have been researched and a solution based on SubGroup Secure Controllers (SGSCs) is presented, which solves many problems in IOLUS system and WGL scheme.展开更多
Time efficiency of key establishment and update is one of the major problems contributory key managements strive to address.To achieve better time efficiency in key establishment,we propose a Location-based Huffman(L-...Time efficiency of key establishment and update is one of the major problems contributory key managements strive to address.To achieve better time efficiency in key establishment,we propose a Location-based Huffman(L-Huffman) scheme.First,users are separated into several small groups to minimize communication cost when they are distributed over large networks.Second,both user's computation difference and message transmission delay are taken into consideration when Huffman coding is employed to forming the optimal key tree.Third,the combined weights in Huffman tree are located in a higher place of the key tree to reduce the variance of the average key generation time and minimize the longest key generation time.Simulations demonstrate that L-Huffman has much better performance in wide area networks and is a little better in local area network than Huffman scheme.展开更多
The tyre industry is one of the industries with the longest history in modern industry. It embodies a country’s economic and technical power. The United States, Germany, Italy and France are not rubber producers. How...The tyre industry is one of the industries with the longest history in modern industry. It embodies a country’s economic and technical power. The United States, Germany, Italy and France are not rubber producers. However, they had their vehicles equipped with air tyres展开更多
As a large private company starting from feed-processing industry, the East Hope Group has entered the aluminum industry. During the period of less than four years, it has completed two big electrolyticaluminum smelte...As a large private company starting from feed-processing industry, the East Hope Group has entered the aluminum industry. During the period of less than four years, it has completed two big electrolyticaluminum smelters and started the construction of a project of oxide of alumina. With its rapid speed, advanced technology and equipment, and high efficiency, the company has created a miracle in aluminum industry. From the viewpoint of strategic management, the author analyzes the strategic thinking of its entry into the aluminum industry; the strategic measures to build the company into the most competitive enterprise in this industry, and how to maintain a sustainable competitive advantage. Meanwhile, the paper plays an important reference role for the analysis of the private economy, and the enterprises with diversified thinking and those wishing to expand aggressively.展开更多
One day in April,our reporters visitedthis national super-large enterprise.Mr Huang Xiaoping,the generalmanager,briefed us on the company’s brilliantpast and bright future. The Yuejin Auto Group Company isfamed all o...One day in April,our reporters visitedthis national super-large enterprise.Mr Huang Xiaoping,the generalmanager,briefed us on the company’s brilliantpast and bright future. The Yuejin Auto Group Company isfamed all over the world for producing YuejinBrand automobiles.In 1958,the firstgeneration of Yuejin Brand automobiles cameout,and China has since had its first展开更多
基金Hebei University Affiliated Hospital Youth Fund Scientific Research Project Project Number:2019Q017。
文摘Objective:To explore the role of specialized group management in the quality control of perioperative nursing.Methods:45 surgical nurses from our hospital were selected as the research subjects.Traditional operating room management was adopted from July 2019 to June 2020,and specialized group management was adopted from July 2020 to June 2021.The surgeon’s satisfaction,surgical nurses’core professional competence,and surgical patients’satisfaction were obtained through surveys and the results were analyzed.Results:Surgeon satisfaction before the implementation of specialized group management was significantly lower than after its implementation(P<0.05).Besides,surgical nurses’core professional competency scores before the implementation of specialized group management were significantly lower than after its implementation(P<0.05).Lastly,surgical patients’satisfaction before the implementation of specialized group management was significantly lower than after its implementation(P<0.05).Conclusion:Specialized group management helps to improve the quality of perioperative care and should be applied in clinical practice.
文摘Objective: to sort out the clinical value of implementing quality control group management mode in emergency department nursing management, so as to provide reference and reference for gradually improving the quality of emergency nursing. Methods: to sort out the nursing quality assessment results of the nursing staff in the emergency department of our hospital during the period from January 2019 to December 20, 2019, and then compare them with the nursing quality assessment results of the nursing staff after the establishment of the nursing quality control group in 2021, so as to provide reference and reference for the preparation of a scientific, standardized and efficient emergency nursing management plan, so as to continuously improve the nursing level of the undergraduate department. Results: according to the same version of the emergency nursing quality standard, the emergency nursing quality assessment was carried out in 2019 and 2021. It can be found that in 2019, the average of the assessment results was (93.23 ± 2.46) points, and the number of adverse reaction events in the undergraduate department was 10 pieces. In 2021, the average result of roast goose was (97.02 ± 1.49) points, and the number of adverse reaction events occurred in the undergraduate room was 4 pieces. The difference between the two data was prominent and there was a statistical advantage (P < 0.05). Conclusion: in the nursing management of the emergency department, the establishment of the nursing quality control team can play a positive role. It can detect the shortcomings and shortcomings of the nursing period at the first time, and analyze and rectify the root causes, so as to avoid risks, and improve the clinical nursing level and patient satisfaction.
文摘Efficient and safe information exchange between vehicles can reduce the probability of road accidents,thereby improving the driving experience of vehicles in Vehicular Ad Hoc Networks(VANETs).This paper proposes a group management algorithm with trust and mobility evaluation to address the enormous pressure on VANETs topology caused by high-speed vehicle movement and dynamic changes in the direction of travel.This algorithm utilizes historical interactive data to mine the fusion trust between vehicles.Then,combined with fusion mobility,the selection of center members and information maintenance of group members is achieved.Furthermore,based on bilinear pairing,an encryption protocol is designed to solve the problem of key management and update when the group structure changes rapidly,ensuring the safe forwarding of messages within and between groups.Numerical analysis shows that the algorithm in the paper ensures group stability and improves performance such as average message delivery rate and interaction delay.
文摘By introducing XOR operation and one-way function chains to group key management schemes based on the keys tree, a new group key management scheme based on the keys tree, XOR operation and one-way function chains is proposed. Initialization, member adding and member evicting operations are introduced. The new scheme is compared with three other group key management schemes which are based on the keys tree： SKDC, LKH, and OFF. As far as transmission, computation and storage costs are concerned, the performance of the new group key management scheme is the best. The security problem of the new scheme is analyzed. This new scheme provides backward and forward security, i.e.. newly admitted group members cannot read previous multicast messages and evicted members cannot read future multicast messages, even with collusion by many arbitrarily evicted members.
基金Project(61100201) supported by National Natural Science Foundation of ChinaProject(12ZZ019) supported by Technology Innovation Research Program,Shang Municipal Education Commission,China+1 种基金Project(LYM11053) supported by the Foundation for Distinguished Young Talents in Higher Education of Guangdong Province,ChinaProject(NCET-12-0358) supported by New Century Excellent Talentsin University,Ministry of Education,China
文摘The key exposure problem is a practical threat for many security applications. In wireless sensor networks (WSNs), keys could be compromised easily due to its limited hardware protections. A secure group key management scheme is responsible for secure distributing group keys among valid nodes of the group. Based on the key-insulated encryption (KIE), we propose a group key management scheme (KIE-GKMS), which integrates the pair-wise key pre-distribution for WSN. The KIE-GKMS scheme updates group keys dynamically when adding or removing nodes. Moreover, the security analysis proves that the KIE-GKMS scheme not only obtains the semantic security, but also provides the forward and backward security. Finally, the theoretical analysis shows that the KIE-GKMS scheme has constant performance on both communication and storage costs in sensor nodes.
基金Acknowledgements The authors would like to thank the reviewers for their detailed reviews and constructive comments, which have helped improve the quality of this paper. This work was supported by the National Natural Science Foundation of China under Crant No. 60873231, the Natural Science Foundation of Jiangsu Province under Grant No. BK2009426, Major State Basic Research Development Program of China under Cwant No.2011CB302903 and Key University Science Research Project of Jiangsu Province under Crant No. 11KJA520002.
文摘The m ajor advantages of EBS-based key rrkanagerrent scheme are its enhanced network survivability, high dynamic performance, and better support for network expansion. But it suffers from the collusion problem, which means it is prone to the cooperative attack of evicted members. A novel EBS-based collusion resistant group management scheme utilizing the construction of Ciphertext-Policy Attribute-Based Encryption （CP-ABE） is proposed. The new scheme satisfies the desired security properties, such as forward secrecy, backward secrecy and collusion secrecy. Compared with existing EBS-based key rmnagement scheme, the new scheme can resolve EBS collusion problem completely. Even all evicted members work together, and share their individual piece of information, they could not access to the new group key. In addition, our scheme is more efficient in terms of conmnication and computation overhead when the group size is large. It can be well controlled even in the case of large-scale application scenarios.
基金Supported by the National Natural Science Foundation of China (60572162)
文摘Considering the special requirements of group enterprise information management software, a new method of massive software development was put forward basing on the component technology and facing the ＂assemblage＂. It generalizes five key parts of the method system including the overall strategy, the application project method basing on the operation ＂assemblage＂, the field project method basing on component, the development method facing the component on the basis of the visible component platform, and the software development process model basing on the component ＂assemblage＂. Besides, this paper describes the process and principle of this method application with an example of the construction of a Communications Investment Group enterprise＇s management information system. The method provides a new idea for breaking away from the predicament appeared in the construction of present enterprise informatization and exploring the way of software industrialization.
基金partially supported by National Natural Science Foundation of China No.61202034,61232002,61303026,6157237861402339CCF Opening Project of Chinese Information Processing No.CCF2014-01-02+2 种基金the Program for Innovative Research Team of Wuhan No.2014070504020237Fundamental Application Research Plan of Suzhou City No.SYG201312Natural Science Foundation of Wuhan University No.2042016gf0020
文摘Cloud data sharing service, which allows a group of people to work together to access and modify the shared data, is one of the most popular and efficient working styles in the enterprises. However, the cloud server is not completely trusted, and its security could be compromised by monetary reasons or caused by hacking and hardware errors. Therefore, despite of having advantages of scalability and flexibility, cloud storage service comes with privacy and the security concerns. A straightforward method to protect the user's privacy is to encrypt the data stored at the cloud. To enable the authenticated users to access the encrypted cloud data, a practical group key management algorithm for the cloud data sharing application is highly desired. The existing group key management mechanisms presume that the server is trusted. But, the cloud data service mode does not always meet this condition. How to manage the group keys to support the scenario of the cloud storage with a semi-trusted cloud server is still a challenging task. Moreover, the cloud storage system is a large-scale and open application, in which the user group is dynamic. To address this problem, we propose a practical group key management algorithm based on a proxy re-encryption mechanism in this paper. We use the cloud server to act as a proxy tore-encrypt the group key to allow authorized users to decrypt and get the group key by their private key. To achieve the hierarchical access control policy, our scheme enables the cloud server to convert the encrypted group key of the lower group to the upper group. The numerical analysis and experimental results further validate the high efficiency and security of the proposed scheme.
文摘Objective: to explore the application value of group authorization management in improving nursing quality in operating room. Methods: this study was carried out from July 2019 to July 2020. 60 operating room nurses in our hospital were selected as observation objects, and the nurses were equally divided by blind selection method. 30 patients in the control group and 30 patients in the observation group were given conventional management and group authorization management respectively. The incidence of adverse events and skill scores of the two groups of nursing staff were observed and compared. Results: 1 nurse in the observation group had an adverse event, while 8 in the control group. The difference between the two groups was significant (P < 0.05). At the same time, combined with the evaluation of the two groups of nurses' emergency ability score, operation coordination proficiency score and specialized equipment use ability score, the observation group of nurses' skills score was better than the control group, the difference between the indicators is significant (p < 0.05). Conclusion: the implementation of group authorization management for operating room nursing staff can significantly reduce the occurrence of adverse events among nurses and improve the professional skills of nursing staff, which is of great significance to improve the quality of nursing in operating room.
文摘Objective: to analyze the effect of quality control group management in the nursing of nail breast surgery. Methods: from December 2020 to April 2021, 98 cases of patients undergoing nail breast surgery in our hospital were selected as the observation objects of this study. The patients were randomly divided into two groups. The control group adopted routine nursing, and the observation group adopted routine nursing + quality control management. The occurrence of nursing errors and patient satisfaction were compared between the two groups. Results: the incidence of adverse events in observation group was 8.16%, which was lower than that in control group (26.52%) (P < 0.05). The satisfaction of the observation group was 93.88%, which was higher than that of the control group (80.43%) (P < 0.05). Conclusion: the intervention of quality control management on the basis of routine nursing can effectively reduce the occurrence of adverse events such as nursery-patient disputes, improve patient satisfaction, and the effect is ideal.
文摘Intelligent transportation system （ITS） is proposed as the most effective way to improve road safety and traffic efficiency. However, the future of ITS for large scale transportation infrastructures deployment highly depends on the security level of vehicular communication systems （VCS）. Security applications in VCS are fulfilled through secured group broadcast. Therefore, secure key management schemes are considered as a critical research topic for network security. In this paper, we propose a framework for providing secure key management within heterogeneous network. The seeurity managers （SMs） play a key role in the framework by retrieving the vehicle departnre infi^rmation, encapsulating block to transport keys and then executing rekeying to vehicles within the same security domain. The first part of this framework is a novel Group Key Management （GKM） scheme basing on leaving probability （LP） of vehicles to depart current VCS region. Vehicle＇s LP factor is introduced into GKM scheme to achieve a more effieient rekeying scheme and less rekeying costs. The second component of the framework using the blockchain concept to simplify the distributed key management in heterogeneous VCS domains. Extensive simulations and analysis are provided to show the effectiveness and effieiency of the proposed framework： Our GKM results demonstrate that probability-based BR reduees rekeying eost compared to the benchmark scheme, while the blockchain deereases the time eost of key transmission over heterogeneous net-works.
基金Supported by the National Natural Science Foundation of China(60572049)
文摘Secure group communications are restrained by the number of the group size,number of changes and their distribution,all existing works do not meet the commands of applications with large group size and high dynamic members.In this paper,minimum exact cover problem for group key distribution(GMECP)is presented,and a heuristic solution is testified.Then an algorithm of batch rekeying with renewing cost tending to zero is illustrated,which can process any large number of change requests with best security guaranteed.Efficiency analysis and simulation test show that the achievement can improve the efficiency of any tree-based group key management.
文摘Group work has many advantages from language acquisition point of view. However, some teachers are unwilling to introduce group work in their own classroom because group work is very difficult to manage. The author of this essay explores the discourse features of successful and unsuccessful group work using discourse analysis in the hope that the results of this language classroom research can help language teachers gain some insight into the use of group work and make more informed decisions about group work management.
文摘As the major problem in multicast security, the group key management has been the focus of research But few results are satisfactory. In this paper, the problems of group key management and access control for large dynamic multicast group have been researched and a solution based on SubGroup Secure Controllers (SGSCs) is presented, which solves many problems in IOLUS system and WGL scheme.
基金Supported by National Basic Research and Development Program of China (2007CB307102)
文摘Time efficiency of key establishment and update is one of the major problems contributory key managements strive to address.To achieve better time efficiency in key establishment,we propose a Location-based Huffman(L-Huffman) scheme.First,users are separated into several small groups to minimize communication cost when they are distributed over large networks.Second,both user's computation difference and message transmission delay are taken into consideration when Huffman coding is employed to forming the optimal key tree.Third,the combined weights in Huffman tree are located in a higher place of the key tree to reduce the variance of the average key generation time and minimize the longest key generation time.Simulations demonstrate that L-Huffman has much better performance in wide area networks and is a little better in local area network than Huffman scheme.
文摘The tyre industry is one of the industries with the longest history in modern industry. It embodies a country’s economic and technical power. The United States, Germany, Italy and France are not rubber producers. However, they had their vehicles equipped with air tyres
文摘As a large private company starting from feed-processing industry, the East Hope Group has entered the aluminum industry. During the period of less than four years, it has completed two big electrolyticaluminum smelters and started the construction of a project of oxide of alumina. With its rapid speed, advanced technology and equipment, and high efficiency, the company has created a miracle in aluminum industry. From the viewpoint of strategic management, the author analyzes the strategic thinking of its entry into the aluminum industry; the strategic measures to build the company into the most competitive enterprise in this industry, and how to maintain a sustainable competitive advantage. Meanwhile, the paper plays an important reference role for the analysis of the private economy, and the enterprises with diversified thinking and those wishing to expand aggressively.
文摘One day in April,our reporters visitedthis national super-large enterprise.Mr Huang Xiaoping,the generalmanager,briefed us on the company’s brilliantpast and bright future. The Yuejin Auto Group Company isfamed all over the world for producing YuejinBrand automobiles.In 1958,the firstgeneration of Yuejin Brand automobiles cameout,and China has since had its first
