Magnesium(Mg)alloys are promising candidates for biodegradable implants and medical devices due to their biocompatibility,mechanical properties,and ability to degrade in vivo,thereby eliminating the need for secondary...Magnesium(Mg)alloys are promising candidates for biodegradable implants and medical devices due to their biocompatibility,mechanical properties,and ability to degrade in vivo,thereby eliminating the need for secondary removal surgeries[1,2].However,their clinical adoption is hindered by rapid corrosion in physiological environments[3–5].Due to the high chemical reactivity of magnesium substrates and the inability of primary corrosion degradation products to form ideal protective layers,no effective scientific guidance has yet been identified from fundamental material science to address the rapid degradation of bare Mg[6–8].Surface modification strategies equivalently create new materials wrapped in a matrix,which can thus be extensively explored to enhance the corrosion resistance of Mg alloys while endowing them with tailored biological functionalities[9,10].展开更多
RNA interference(RNAi)is a post-transcriptional gene-silencing technique induced by the introduction of double-stranded RNA(dsRNA)or small interfering RNA(siRNA)[1].RNAi-based strategies have been extensively applied ...RNA interference(RNAi)is a post-transcriptional gene-silencing technique induced by the introduction of double-stranded RNA(dsRNA)or small interfering RNA(siRNA)[1].RNAi-based strategies have been extensively applied in the treatment of human diseases and crop protection against insect pests[2-4].With the availability of the full genome sequences of major mosquito vectors,RNAi has become increasingly used as a novel means of mosquito control[5].展开更多
With the rapid development of computer technology, cloud-based services have become a hot topic. They not only provide users with convenience, but also bring many security issues, such as data sharing and privacy issu...With the rapid development of computer technology, cloud-based services have become a hot topic. They not only provide users with convenience, but also bring many security issues, such as data sharing and privacy issue. In this paper, we present an access control system with privilege separation based on privacy protection(PS-ACS). In the PS-ACS scheme, we divide users into private domain(PRD) and public domain(PUD) logically. In PRD, to achieve read access permission and write access permission, we adopt the Key-Aggregate Encryption(KAE) and the Improved Attribute-based Signature(IABS) respectively. In PUD, we construct a new multi-authority ciphertext policy attribute-based encryption(CP-ABE) scheme with efficient decryption to avoid the issues of single point of failure and complicated key distribution, and design an efficient attribute revocation method for it. The analysis and simulation result show that our scheme is feasible and superior to protect users' privacy in cloud-based services.展开更多
Silica-based materials are widely employed in the thermal protection system for hypersonic vehicles, and the investigation of their catalytic characteristics is crucially important for accurate aerothermal heating pre...Silica-based materials are widely employed in the thermal protection system for hypersonic vehicles, and the investigation of their catalytic characteristics is crucially important for accurate aerothermal heating prediction. By analyzing the disadvantages of Norman＇s high and low temperature models, this paper combines the two models and proposes an eight-reaction combined surface catalytic model to describe the catalysis between oxygen and silica surface. Given proper evaluation of the parameters according to many references, the recombination coefficient obtained shows good agreement with experimental data. The catalytic mechanisms between oxygen and silica surface are then analyzed. Results show that with the increase of the wall temperature, the dominant reaction contributing to catalytic coefficient varies from Langmuir Hinshelwood （LH） recombination （Tw 〈 620 K） to Eley Rideal （ER） replacement （620 K 〈 Tw 〈 1350 K）, and then to 02 desorption （Tw 〉 1350 K）. The surface coverage of chemisorption areas varies evidently with the dominant reactions in the high temperature （HT） range, while the surface coverage of physisorption areas varies within quite low temperature （LT） range （Tw 〈 250 K）. Recommended evaluation of partial parameters is also given.展开更多
To solve the problem that the traditional location-based services anonymity model is not applied to the continuous query, quasi real-time cloak algorithm （QR-TCA） has been proposed, and the non-delay cloak model （N...To solve the problem that the traditional location-based services anonymity model is not applied to the continuous query, quasi real-time cloak algorithm （QR-TCA） has been proposed, and the non-delay cloak model （N-DCM） has been established. After comprehensive analysis of location-based continuous query privacy protection models, a model that can solve the user service delay problem is proposed, which can provide the users with quasi-real time location-based services. The experiment measures the N-DCM model with multiple dimensions, such as service response time and service quality of standard datasets. The experiment results show that the method is suitable for continuous query location privacy protection and can effectively protect the user’s location privacy.展开更多
Community-based tourism (CBT) is considered as one of the typical types of tourism towards sustainable development with three important goals such as bringing back economic benefits, protecting natural environment and...Community-based tourism (CBT) is considered as one of the typical types of tourism towards sustainable development with three important goals such as bringing back economic benefits, protecting natural environment and preserving indigenous cultural values. Therefore, this paper analyzes the factors that affect community ecotourism development associated with environmental protection in emerging economies, including Vietnam, by the method of key and community tourism potential value assessment with 721 sample surveys. In this paper, we have applied to assess the key factors of tourism in Vietnam and other key points to have more comprehensive solutions to promote the development of community-based tourism with environmental protection. The article has used vip-based approach and method of assessing the key success factors. The results of researching factors to develop community tourist (impacting tourist community needs of tourists) by running Logit function have shown the great influence of factors such as: environmental protection (influence factor +3.585780, with a statistical significance of 99%), security and safety (+3.024816—statistical significance 99%) followed by infrastructure conditions & facilities for the community based tourism, the level of information etc… for your community based tourism needs. From the research results, we propose the following policy groups: 1) Developing guidelines for CBT, the first step as a basis for the development of community based tourism laws later;2) Policies related to the implementation of planning, development of key community tourist areas and destinations;3) Policies related to the development of community-based tourism associated with the protection of natural and cultural environments;4) Policies related to tourism management;coordinating monitoring of community tourism resource points;policies related to the local community in community tourism development;5) Policies related to human resource development;promotion work;developing community based tourism products.展开更多
Aiming at the problem of dynamic multicast service protection in multi-domain optical network, this paper proposes a dynamic multicast sharing protection algorithm based on fuzzy game in multi-domain optical network. ...Aiming at the problem of dynamic multicast service protection in multi-domain optical network, this paper proposes a dynamic multicast sharing protection algorithm based on fuzzy game in multi-domain optical network. The algorithm uses the minimum cost spanning tree strategy and fuzzy game theory. First, it virtualizes two planes to calculate the multicast tree and the multicast protection tree respectively. Then, it performs a fuzzy game to form a cooperative alliance to optimize the path composition of each multicast tree. Finally, it generates a pair of optimal multicast work tree and multicast protection tree for dynamic multicast services. The time complexity of the algorithm is O(k3 m2 n), where n represents the number of nodes in the networks, k represents the number of dynamic multicast requests, and m represents the number of destination nodes for each multicast request. The experimental results show that the proposed algorithm reduces significantly the blocking rate of dynamic multicast services, and improves the utilization of optical network resources within a certain number of dynamic multicast request ranges.展开更多
When the user getting location based services by the traditional technology,his location information of region is always be exposed.However,in modern mobile networks,even the current geographical region is a part of p...When the user getting location based services by the traditional technology,his location information of region is always be exposed.However,in modern mobile networks,even the current geographical region is a part of privacy information.To solve this problem,a new generalized k-anonymity location privacy protection scheme in location based services(LPPS-GKA)with the third trust servicer is proposed.And it can guarantee the users get good location-based services(LBS)without leaking the information of the geo-location region,which has protected the perfect privacy.Analysis shows that LPPS-GKA is more secure in protecting location privacy,including region information,and is more efficient than other similar schemes in computational and communicational aspects.It is suitable for dynamic environment for different user’s various privacy protection requests.展开更多
Static secure techniques, such as firewall, hierarchy filtering, distributed disposing,layer management, autonomy agent, secure communication, were introduced in distributed intrusion detection. The self-protection ag...Static secure techniques, such as firewall, hierarchy filtering, distributed disposing,layer management, autonomy agent, secure communication, were introduced in distributed intrusion detection. The self-protection agents were designed, which have the distributed architecture,cooperate with the agents in intrusion detection in a loose-coupled manner, protect the security of intrusion detection system, and respond to the intrusion actively. A prototype self-protection agent was implemented by using the packet filter in operation system kernel. The results show that all the hosts with the part of network-based intrusion detection system and the whole intrusion detection system are invisible from the outside and network scanning, and cannot apperceive the existence of network-based intrusion detection system. The communication between every part is secure. In the low layer, the packet streams are controlled to avoid the buffer leaks exist ing in some system service process and back-door programs, so as to prevent users from misusing and vicious attack like Trojan Horse effectively.展开更多
The selection of policy instruments involves policy efficiency and policy effect.Effective settlement of eco-environment problems in the process of industrialization and implementation of active eco-environment protec...The selection of policy instruments involves policy efficiency and policy effect.Effective settlement of eco-environment problems in the process of industrialization and implementation of active eco-environment protection depend on the innovation of policy instruments.In this paper,based on a descriptive analysis of the policy instruments for ecoenvironmental protection of our country,combined with the theoretical analysis and the empirical research on current marketization of eco-environmental protection,the authors indicate that eco-environmental problems originate fi'om the damage of eco-environment and the extemalities of eco-service,and that the market-based policy instruments which are helpful to balance the relationship between fight,responsibility and interest in the eco-service are effective measures to eliminate externalities and protect eco-environment.展开更多
This paper proposes an unequal error protection（UEP）coding method to improve the transmission performance of three-dimensional（3D）audio based on expanding window fountain（EWF）.Different from other transmissions ...This paper proposes an unequal error protection（UEP）coding method to improve the transmission performance of three-dimensional（3D）audio based on expanding window fountain（EWF）.Different from other transmissions with equal error protection（EEP）when transmitting the 3D audio objects.An approach of extracting the important audio object is presented,and more protection is given to more important audio object and comparatively less protection is given to the normal audio objects.Objective and subjective experiments have shown that the proposed UEP method achieves better performance than equal error protection method,while the bits error rates（BER）of the important audio object can decrease from 10^（–3） to 10^（–4）,and the subjective quality of UEP is better than that of EEP by 14%.展开更多
Ecosystem-based management and community-based participation in governance of Marine Protected Areas (MPAs) have been identified as key elements to improve management success, local stakeholder support, and compliance...Ecosystem-based management and community-based participation in governance of Marine Protected Areas (MPAs) have been identified as key elements to improve management success, local stakeholder support, and compliance with regulations. However, both are often rarely achieved, resulting in poor MPA governance, support and success. A quantitative assessment of the spatio- temporal change (1997-2012) of coral reef fish communities within Arrecifes La Cordillera Natural Reserve in northeastern Puerto Rico was carried out. We also identified community expectations of and support for the designation of a network of small no-take MPAs within the reserve’s boundaries. A holistic approach employing biophysical and socioeconomic methods was used as part of a participatory model to identify priorities for the designation of candidate no-take MPAs. Populations of the most important fishery-targeted species showed a significant temporal decline, particularly in areas subjected to intense recreational activities and spearfishing. Most groupers (Serranidae), snappers (Lutjanidae), barracudas (Sphyraenidae), and some parrotfishes (Scaridae) were nearly absent at most sites. Most individuals belonged to smaller size categories. Herbivores represented the majority of the total fish biomass, suggesting strong fishing impacts on apex predators. Fish declines also occurred after two massive coral bleaching events in 1998 and 2005 that were followed by mass coral mortalities, suggesting combined negative impacts of fishing and climate change. A no-take MPA designation was supported by 80% of the artisanal fishermen, 73% of the concessionaires (i.e., SCUBA diving, charter boats), and 52% of registered vessel operators. Stakeholders agreed that coral reef conditions in the reserve had declined over time, as well as water quality which affected reef health and fisheries. Stakeholders did not recognize climate change and sea surface warming as threats to coral reefs and fisheries. Nonetheless, stakeholder perceptions of candidate no-take MPA sites remarkably matched those identified through fish counts. This study also highlighted the pervasive views held by many stake-holders concerning MPA management and enforcement, and recommended that any no-take MPA designation process considers improving stakeholder participation, understanding of management objectives, actions, and accomplishments, and building stakeholders trust. The integration of ecosystem-based and community-based participatory models may be critical to foster improved support of no-take MPAs and foster a long-term community-based integration to develop and implement mitigation strategies for climate change impacts in novel future scenarios.展开更多
In this paper,we generally summarize the main issues in the operational period of water conservancy and hydropower projects in China over the past several decades.First,the adverse impacts of these projects since the ...In this paper,we generally summarize the main issues in the operational period of water conservancy and hydropower projects in China over the past several decades.First,the adverse impacts of these projects since the technical guidelines were proposed in 2006 are analyzed.Then,combined with projects and experience from 2006 to 2014,the four main issues are summarized:(1) There exist many questions in the design and construction of fishways,which are useful for fish migration,and the migration effects are not as expected.(2) Temperature stratification affecting the downstream fish is the major impact of temperature,and alters fish spawning in the reproduction season.(3)Ecological base flow has been one of the primary questions of the last 30 years in China,the greatest related difficulty being quantification of the amount and flow process necessary to satisfy fish life history.(4) Fish habitat protection and restoration are popular topics in recent years with the development of river ecosystem restoration.Fish habitat loss due to the impacts of dam construction and habitat fragmentation has become more and more serious.These four issues are now the main difficulties in water project management,and interact with one another to bear combined effects on river ecosystems.The issues of eco-hydraulic consideration in the design period are the key factors.Finally,future priorities for research and practice of environmental protection for water conservancy and hydropower projects in China are proposed.The main purpose of this paper is to enhance the scientific research,monitoring,and assessment of operating effectiveness.展开更多
High quality electricity services are the prime objectives in the modern power systems around the world. One of the main players to achieve this is the protection of the system which needs to be fast, reliable and cos...High quality electricity services are the prime objectives in the modern power systems around the world. One of the main players to achieve this is the protection of the system which needs to be fast, reliable and cost effective. The study about the protection of the Low Voltage (LV) CIGRE distribution grid and networks like this has been proposed in this paper. The main objective of this paper is to develop protection against short circuit faults which might appear anywhere in the network. The protection of the power networks that comprises of renewable energy generation units is complicated because of the bidirectional flow of the current and is a challenge for the protection engineers. The selection of the protection devices in this paper is made to protect the network against faults in grid connected and island mode of operation. Ultra-fast fuses are proposed in order to protect the inverters used for Photovoltaic (PV) and battery applications. The disconnection of the PV solar panels when in island mode is made by proposing switch disconnecting devices. ABB is currently using these kinds of disconnection devices for the purpose of protecting solar panels against over voltages in the case of islanding. The over speed protection of the existing Wind Turbine Generator (WTG) in the CIGRE network in case of grid loss is also proposed in this paper.展开更多
In order to study the dynamic behaviors of the thermal protection system(TPS)and dynamic strength of the strain-isolation-pad(SIP),a two degree-of-freedom dynamic theoretical model is presented under the acoustic exci...In order to study the dynamic behaviors of the thermal protection system(TPS)and dynamic strength of the strain-isolation-pad(SIP),a two degree-of-freedom dynamic theoretical model is presented under the acoustic excitation and base excitation. The tile and SIP are both considered as the elastic body and simplified as a mass point,a linear spring and a damping element. The theoretical solutions are derived,and the reasonability of theoretical model is verified by comparing the theoretical results with the numerical results. Finally,the influences on the dynamic responses of TPS by the structural damping coefficient of TPS,elasticity modulus and thickness of SIP are analyzed.The results show that the material with higher damping,and SIP with thicker size and lower elastic modulus should be considered to reduce the dynamic responses and intensify the security of TPS. The researches provide a theoretical reference for studying the dynamic behaviors of TPS and the dynamic strength of SIP. Besides,the dynamic theoretical model can be used as a quick analysis tool for analyzing the dynamic responses of TPS during the initial design phase.展开更多
This paper presents an integrated relay and its associated protection scheme for power transmission lines.The concept of integrated protection is firstly introduced,in which a centralized protection system or relay pr...This paper presents an integrated relay and its associated protection scheme for power transmission lines.The concept of integrated protection is firstly introduced,in which a centralized protection system or relay provides the protection for multiple power plants or a substation.A novel integrated protection relay based on the combination of a number of protection principles is described.In the proposed scheme,the specially designed protection relays are installed at each substation of a network and are responsible for the protection of every line section connected to the substation busbar.The combined algorithms with multiple settings are implemented into the relay to cover all the protected line sections.Simulation studies show that the proposed protection scheme is able to produce desirable performance and may offer many advantages over the existing one and great potential for future applications.展开更多
To resolve the impact of transient high frequency signals induced by lightning stroke on the travelling wave protection of transmission line, a novel identification algorithm is proposed. Using the characteristics of ...To resolve the impact of transient high frequency signals induced by lightning stroke on the travelling wave protection of transmission line, a novel identification algorithm is proposed. Using the characteristics of symmetric current wave-form induced by lightning stroke without causing fault and that of asymmetric current waveform generated by fault within a very short time interval, the waveform of transient current above and below time-axes are integrated respec-tively. First, through comparing the relative ratio of them with threshold value, the primary criterion identifying fault and lightning stroke is constructed;Secondly, to improve the reliability of discrimination between lightning stroke with and without causing fault, according to the difference of them, the secondary criterion is also defined. The simulation results and analysis demonstrate that the proposed integral criterions are valid and correct.展开更多
Aiming at digital relay protection system, a novel hidden failure Markov reliability model is presented for a single main protection and double main protection systems according to hidden failure and protection functi...Aiming at digital relay protection system, a novel hidden failure Markov reliability model is presented for a single main protection and double main protection systems according to hidden failure and protection function under Condition-Based Maintenance (CBM) circumstance and reliability indices such as probability of protection system hidden failure state are calculated. Impacts of different parameters (containing impacts of human errors) to hidden failure state probability and the optimal measures to improve reliability by variable parameter method are also analyzed. It’s demonstrated here that: Compared to a single main protection, double main protection system has an increased hidden failure probability, thus the real good state probability decreases, two main protections’ reliability must be improved at the same time, so configuration of the whole protection system for the component being protected can’t be complicated. Through improving means of on-line self-checking and monitoring system in digital protection system and human reliability, the real application of CBM can decrease hidden failure state probability. Only through this way can we assure that the protection systems work in good state. It has a certain reference value to protection system reliability engineering.展开更多
In response to the frequent safety accidents of industrial robots, this paper designs and implements a safety detection system for robot control. It can perform real-time security detection of robot operations on indu...In response to the frequent safety accidents of industrial robots, this paper designs and implements a safety detection system for robot control. It can perform real-time security detection of robot operations on industrial production lines to improve the security and reliability of robot control systems. This paper designs and implements a robot control system based Snort-BASE for real-time online detection of DoS attacks. The system uses a six-degree-of-freedom robotic arm as an example, uses Snort to record the network communication data of the robot arm control system in real time, and filters the network traffic through self-defined rules, and then uses the BASE analysis platform to achieve security analysis of the network traffic. The solution verifies the effectiveness of online real-time detection of attacks and visualisation of attack records by designing simulated robotic arm and real robotic arm attack experiments respectively, thus achieving the security of network communication of the robot remote control system.展开更多
基金supported by grants from the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Major/key program(No.23M1060280)the Fundamental Research Funds for the Central Universities(No.2232024D-34 and No 2232023A-10).
文摘Magnesium(Mg)alloys are promising candidates for biodegradable implants and medical devices due to their biocompatibility,mechanical properties,and ability to degrade in vivo,thereby eliminating the need for secondary removal surgeries[1,2].However,their clinical adoption is hindered by rapid corrosion in physiological environments[3–5].Due to the high chemical reactivity of magnesium substrates and the inability of primary corrosion degradation products to form ideal protective layers,no effective scientific guidance has yet been identified from fundamental material science to address the rapid degradation of bare Mg[6–8].Surface modification strategies equivalently create new materials wrapped in a matrix,which can thus be extensively explored to enhance the corrosion resistance of Mg alloys while endowing them with tailored biological functionalities[9,10].
基金supported by grants from the National Key Research and Development Program(2023YFE0113600).
文摘RNA interference(RNAi)is a post-transcriptional gene-silencing technique induced by the introduction of double-stranded RNA(dsRNA)or small interfering RNA(siRNA)[1].RNAi-based strategies have been extensively applied in the treatment of human diseases and crop protection against insect pests[2-4].With the availability of the full genome sequences of major mosquito vectors,RNAi has become increasingly used as a novel means of mosquito control[5].
基金financially supported by the National Natural Science Foundation of China(No.61303216,No.61272457,No.U1401251,and No.61373172)the National High Technology Research and Development Program of China(863 Program)(No.2012AA013102)National 111 Program of China B16037 and B08038
文摘With the rapid development of computer technology, cloud-based services have become a hot topic. They not only provide users with convenience, but also bring many security issues, such as data sharing and privacy issue. In this paper, we present an access control system with privilege separation based on privacy protection(PS-ACS). In the PS-ACS scheme, we divide users into private domain(PRD) and public domain(PUD) logically. In PRD, to achieve read access permission and write access permission, we adopt the Key-Aggregate Encryption(KAE) and the Improved Attribute-based Signature(IABS) respectively. In PUD, we construct a new multi-authority ciphertext policy attribute-based encryption(CP-ABE) scheme with efficient decryption to avoid the issues of single point of failure and complicated key distribution, and design an efficient attribute revocation method for it. The analysis and simulation result show that our scheme is feasible and superior to protect users' privacy in cloud-based services.
基金co-supported by the National Natural Science Foundation of China (No. 51306204)the Natural Science Foundation of Hunan Province (No. 13JJ2002)
文摘Silica-based materials are widely employed in the thermal protection system for hypersonic vehicles, and the investigation of their catalytic characteristics is crucially important for accurate aerothermal heating prediction. By analyzing the disadvantages of Norman＇s high and low temperature models, this paper combines the two models and proposes an eight-reaction combined surface catalytic model to describe the catalysis between oxygen and silica surface. Given proper evaluation of the parameters according to many references, the recombination coefficient obtained shows good agreement with experimental data. The catalytic mechanisms between oxygen and silica surface are then analyzed. Results show that with the increase of the wall temperature, the dominant reaction contributing to catalytic coefficient varies from Langmuir Hinshelwood （LH） recombination （Tw 〈 620 K） to Eley Rideal （ER） replacement （620 K 〈 Tw 〈 1350 K）, and then to 02 desorption （Tw 〉 1350 K）. The surface coverage of chemisorption areas varies evidently with the dominant reactions in the high temperature （HT） range, while the surface coverage of physisorption areas varies within quite low temperature （LT） range （Tw 〈 250 K）. Recommended evaluation of partial parameters is also given.
基金Supported by the National Natural Science Foundation(61170035, 61272420)the Natural Science Foundation of Jiangsu Province(BK2011022, BK2011702)+2 种基金the Fundamental Research Funds for the Central Universities (30920130112006)Jiangsu Province Blue Project Innovation team,Nanjing science and technology project (020142010)Nanjing University of Science and Technology in 2009 Zijin Star Project Funding
文摘To solve the problem that the traditional location-based services anonymity model is not applied to the continuous query, quasi real-time cloak algorithm （QR-TCA） has been proposed, and the non-delay cloak model （N-DCM） has been established. After comprehensive analysis of location-based continuous query privacy protection models, a model that can solve the user service delay problem is proposed, which can provide the users with quasi-real time location-based services. The experiment measures the N-DCM model with multiple dimensions, such as service response time and service quality of standard datasets. The experiment results show that the method is suitable for continuous query location privacy protection and can effectively protect the user’s location privacy.
文摘Community-based tourism (CBT) is considered as one of the typical types of tourism towards sustainable development with three important goals such as bringing back economic benefits, protecting natural environment and preserving indigenous cultural values. Therefore, this paper analyzes the factors that affect community ecotourism development associated with environmental protection in emerging economies, including Vietnam, by the method of key and community tourism potential value assessment with 721 sample surveys. In this paper, we have applied to assess the key factors of tourism in Vietnam and other key points to have more comprehensive solutions to promote the development of community-based tourism with environmental protection. The article has used vip-based approach and method of assessing the key success factors. The results of researching factors to develop community tourist (impacting tourist community needs of tourists) by running Logit function have shown the great influence of factors such as: environmental protection (influence factor +3.585780, with a statistical significance of 99%), security and safety (+3.024816—statistical significance 99%) followed by infrastructure conditions & facilities for the community based tourism, the level of information etc… for your community based tourism needs. From the research results, we propose the following policy groups: 1) Developing guidelines for CBT, the first step as a basis for the development of community based tourism laws later;2) Policies related to the implementation of planning, development of key community tourist areas and destinations;3) Policies related to the development of community-based tourism associated with the protection of natural and cultural environments;4) Policies related to tourism management;coordinating monitoring of community tourism resource points;policies related to the local community in community tourism development;5) Policies related to human resource development;promotion work;developing community based tourism products.
基金supported by the National Natural Science Foundation of China (No.61402529)the Natural Science Basic Research Plan in Shanxi Province of China (No.2020JM-361)+1 种基金the Young and Middle-aged Scientific Research Backbone Projects of Engineering University of PAP (No.KYGG201905)the Basic Researchof Engineering University of PAP (Nos.WJY201920 and WJY202019)。
文摘Aiming at the problem of dynamic multicast service protection in multi-domain optical network, this paper proposes a dynamic multicast sharing protection algorithm based on fuzzy game in multi-domain optical network. The algorithm uses the minimum cost spanning tree strategy and fuzzy game theory. First, it virtualizes two planes to calculate the multicast tree and the multicast protection tree respectively. Then, it performs a fuzzy game to form a cooperative alliance to optimize the path composition of each multicast tree. Finally, it generates a pair of optimal multicast work tree and multicast protection tree for dynamic multicast services. The time complexity of the algorithm is O(k3 m2 n), where n represents the number of nodes in the networks, k represents the number of dynamic multicast requests, and m represents the number of destination nodes for each multicast request. The experimental results show that the proposed algorithm reduces significantly the blocking rate of dynamic multicast services, and improves the utilization of optical network resources within a certain number of dynamic multicast request ranges.
基金This work was supported in part by the National Natural Science Foundation of China(Nos.61272492 and 61572521),Shaanxi Province Natural Science Foundation of China(No.2015JM6353)and the Basic Foundation of Engineering University of CAPF(No.WJY201521).
文摘When the user getting location based services by the traditional technology,his location information of region is always be exposed.However,in modern mobile networks,even the current geographical region is a part of privacy information.To solve this problem,a new generalized k-anonymity location privacy protection scheme in location based services(LPPS-GKA)with the third trust servicer is proposed.And it can guarantee the users get good location-based services(LBS)without leaking the information of the geo-location region,which has protected the perfect privacy.Analysis shows that LPPS-GKA is more secure in protecting location privacy,including region information,and is more efficient than other similar schemes in computational and communicational aspects.It is suitable for dynamic environment for different user’s various privacy protection requests.
文摘Static secure techniques, such as firewall, hierarchy filtering, distributed disposing,layer management, autonomy agent, secure communication, were introduced in distributed intrusion detection. The self-protection agents were designed, which have the distributed architecture,cooperate with the agents in intrusion detection in a loose-coupled manner, protect the security of intrusion detection system, and respond to the intrusion actively. A prototype self-protection agent was implemented by using the packet filter in operation system kernel. The results show that all the hosts with the part of network-based intrusion detection system and the whole intrusion detection system are invisible from the outside and network scanning, and cannot apperceive the existence of network-based intrusion detection system. The communication between every part is secure. In the low layer, the packet streams are controlled to avoid the buffer leaks exist ing in some system service process and back-door programs, so as to prevent users from misusing and vicious attack like Trojan Horse effectively.
基金Gradual Achievement of the Planning Project funded by the Ministry of Education "Research on Market-based Policy Instruments for Ecological Compensation"(Grant No.11YJA630110)
文摘The selection of policy instruments involves policy efficiency and policy effect.Effective settlement of eco-environment problems in the process of industrialization and implementation of active eco-environment protection depend on the innovation of policy instruments.In this paper,based on a descriptive analysis of the policy instruments for ecoenvironmental protection of our country,combined with the theoretical analysis and the empirical research on current marketization of eco-environmental protection,the authors indicate that eco-environmental problems originate fi'om the damage of eco-environment and the extemalities of eco-service,and that the market-based policy instruments which are helpful to balance the relationship between fight,responsibility and interest in the eco-service are effective measures to eliminate externalities and protect eco-environment.
基金Supported by the National High Technology Research and Development Program of China(863 Program,2015AA016306)the National Natural Science Foundation of China(61662010,61231015,61471271)+1 种基金Science and Technology Plan Projects of Shenzhen(ZDSYS2014050916575763)Science and Technology Foundation of Guizhou Province(LKS[2011]1)
文摘This paper proposes an unequal error protection（UEP）coding method to improve the transmission performance of three-dimensional（3D）audio based on expanding window fountain（EWF）.Different from other transmissions with equal error protection（EEP）when transmitting the 3D audio objects.An approach of extracting the important audio object is presented,and more protection is given to more important audio object and comparatively less protection is given to the normal audio objects.Objective and subjective experiments have shown that the proposed UEP method achieves better performance than equal error protection method,while the bits error rates（BER）of the important audio object can decrease from 10^（–3） to 10^（–4）,and the subjective quality of UEP is better than that of EEP by 14%.
文摘Ecosystem-based management and community-based participation in governance of Marine Protected Areas (MPAs) have been identified as key elements to improve management success, local stakeholder support, and compliance with regulations. However, both are often rarely achieved, resulting in poor MPA governance, support and success. A quantitative assessment of the spatio- temporal change (1997-2012) of coral reef fish communities within Arrecifes La Cordillera Natural Reserve in northeastern Puerto Rico was carried out. We also identified community expectations of and support for the designation of a network of small no-take MPAs within the reserve’s boundaries. A holistic approach employing biophysical and socioeconomic methods was used as part of a participatory model to identify priorities for the designation of candidate no-take MPAs. Populations of the most important fishery-targeted species showed a significant temporal decline, particularly in areas subjected to intense recreational activities and spearfishing. Most groupers (Serranidae), snappers (Lutjanidae), barracudas (Sphyraenidae), and some parrotfishes (Scaridae) were nearly absent at most sites. Most individuals belonged to smaller size categories. Herbivores represented the majority of the total fish biomass, suggesting strong fishing impacts on apex predators. Fish declines also occurred after two massive coral bleaching events in 1998 and 2005 that were followed by mass coral mortalities, suggesting combined negative impacts of fishing and climate change. A no-take MPA designation was supported by 80% of the artisanal fishermen, 73% of the concessionaires (i.e., SCUBA diving, charter boats), and 52% of registered vessel operators. Stakeholders agreed that coral reef conditions in the reserve had declined over time, as well as water quality which affected reef health and fisheries. Stakeholders did not recognize climate change and sea surface warming as threats to coral reefs and fisheries. Nonetheless, stakeholder perceptions of candidate no-take MPA sites remarkably matched those identified through fish counts. This study also highlighted the pervasive views held by many stake-holders concerning MPA management and enforcement, and recommended that any no-take MPA designation process considers improving stakeholder participation, understanding of management objectives, actions, and accomplishments, and building stakeholders trust. The integration of ecosystem-based and community-based participatory models may be critical to foster improved support of no-take MPAs and foster a long-term community-based integration to develop and implement mitigation strategies for climate change impacts in novel future scenarios.
基金supported by a General Financial Grant from the China Postdoctoral Science Foundation(Grant No.2016M592404)the projects funded by the China Three Gorges Corporation(Grants No.0799556 and0799564)
文摘In this paper,we generally summarize the main issues in the operational period of water conservancy and hydropower projects in China over the past several decades.First,the adverse impacts of these projects since the technical guidelines were proposed in 2006 are analyzed.Then,combined with projects and experience from 2006 to 2014,the four main issues are summarized:(1) There exist many questions in the design and construction of fishways,which are useful for fish migration,and the migration effects are not as expected.(2) Temperature stratification affecting the downstream fish is the major impact of temperature,and alters fish spawning in the reproduction season.(3)Ecological base flow has been one of the primary questions of the last 30 years in China,the greatest related difficulty being quantification of the amount and flow process necessary to satisfy fish life history.(4) Fish habitat protection and restoration are popular topics in recent years with the development of river ecosystem restoration.Fish habitat loss due to the impacts of dam construction and habitat fragmentation has become more and more serious.These four issues are now the main difficulties in water project management,and interact with one another to bear combined effects on river ecosystems.The issues of eco-hydraulic consideration in the design period are the key factors.Finally,future priorities for research and practice of environmental protection for water conservancy and hydropower projects in China are proposed.The main purpose of this paper is to enhance the scientific research,monitoring,and assessment of operating effectiveness.
文摘High quality electricity services are the prime objectives in the modern power systems around the world. One of the main players to achieve this is the protection of the system which needs to be fast, reliable and cost effective. The study about the protection of the Low Voltage (LV) CIGRE distribution grid and networks like this has been proposed in this paper. The main objective of this paper is to develop protection against short circuit faults which might appear anywhere in the network. The protection of the power networks that comprises of renewable energy generation units is complicated because of the bidirectional flow of the current and is a challenge for the protection engineers. The selection of the protection devices in this paper is made to protect the network against faults in grid connected and island mode of operation. Ultra-fast fuses are proposed in order to protect the inverters used for Photovoltaic (PV) and battery applications. The disconnection of the PV solar panels when in island mode is made by proposing switch disconnecting devices. ABB is currently using these kinds of disconnection devices for the purpose of protecting solar panels against over voltages in the case of islanding. The over speed protection of the existing Wind Turbine Generator (WTG) in the CIGRE network in case of grid loss is also proposed in this paper.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘In order to study the dynamic behaviors of the thermal protection system(TPS)and dynamic strength of the strain-isolation-pad(SIP),a two degree-of-freedom dynamic theoretical model is presented under the acoustic excitation and base excitation. The tile and SIP are both considered as the elastic body and simplified as a mass point,a linear spring and a damping element. The theoretical solutions are derived,and the reasonability of theoretical model is verified by comparing the theoretical results with the numerical results. Finally,the influences on the dynamic responses of TPS by the structural damping coefficient of TPS,elasticity modulus and thickness of SIP are analyzed.The results show that the material with higher damping,and SIP with thicker size and lower elastic modulus should be considered to reduce the dynamic responses and intensify the security of TPS. The researches provide a theoretical reference for studying the dynamic behaviors of TPS and the dynamic strength of SIP. Besides,the dynamic theoretical model can be used as a quick analysis tool for analyzing the dynamic responses of TPS during the initial design phase.
基金National Natural Science Foundation of China(No.50077011 and 50377019)National Basic Research Project("973"Project No.2004CB217906).
文摘This paper presents an integrated relay and its associated protection scheme for power transmission lines.The concept of integrated protection is firstly introduced,in which a centralized protection system or relay provides the protection for multiple power plants or a substation.A novel integrated protection relay based on the combination of a number of protection principles is described.In the proposed scheme,the specially designed protection relays are installed at each substation of a network and are responsible for the protection of every line section connected to the substation busbar.The combined algorithms with multiple settings are implemented into the relay to cover all the protected line sections.Simulation studies show that the proposed protection scheme is able to produce desirable performance and may offer many advantages over the existing one and great potential for future applications.
文摘To resolve the impact of transient high frequency signals induced by lightning stroke on the travelling wave protection of transmission line, a novel identification algorithm is proposed. Using the characteristics of symmetric current wave-form induced by lightning stroke without causing fault and that of asymmetric current waveform generated by fault within a very short time interval, the waveform of transient current above and below time-axes are integrated respec-tively. First, through comparing the relative ratio of them with threshold value, the primary criterion identifying fault and lightning stroke is constructed;Secondly, to improve the reliability of discrimination between lightning stroke with and without causing fault, according to the difference of them, the secondary criterion is also defined. The simulation results and analysis demonstrate that the proposed integral criterions are valid and correct.
文摘Aiming at digital relay protection system, a novel hidden failure Markov reliability model is presented for a single main protection and double main protection systems according to hidden failure and protection function under Condition-Based Maintenance (CBM) circumstance and reliability indices such as probability of protection system hidden failure state are calculated. Impacts of different parameters (containing impacts of human errors) to hidden failure state probability and the optimal measures to improve reliability by variable parameter method are also analyzed. It’s demonstrated here that: Compared to a single main protection, double main protection system has an increased hidden failure probability, thus the real good state probability decreases, two main protections’ reliability must be improved at the same time, so configuration of the whole protection system for the component being protected can’t be complicated. Through improving means of on-line self-checking and monitoring system in digital protection system and human reliability, the real application of CBM can decrease hidden failure state probability. Only through this way can we assure that the protection systems work in good state. It has a certain reference value to protection system reliability engineering.
文摘In response to the frequent safety accidents of industrial robots, this paper designs and implements a safety detection system for robot control. It can perform real-time security detection of robot operations on industrial production lines to improve the security and reliability of robot control systems. This paper designs and implements a robot control system based Snort-BASE for real-time online detection of DoS attacks. The system uses a six-degree-of-freedom robotic arm as an example, uses Snort to record the network communication data of the robot arm control system in real time, and filters the network traffic through self-defined rules, and then uses the BASE analysis platform to achieve security analysis of the network traffic. The solution verifies the effectiveness of online real-time detection of attacks and visualisation of attack records by designing simulated robotic arm and real robotic arm attack experiments respectively, thus achieving the security of network communication of the robot remote control system.
