Despite the rapid evolution in all aspects of computer technology, both the computer hardware and software are prone to numerous failure conditions. In this paper, we analyzed the characteristic of a computer system a...Despite the rapid evolution in all aspects of computer technology, both the computer hardware and software are prone to numerous failure conditions. In this paper, we analyzed the characteristic of a computer system and the methods of constructing a system, proposed a communication link management model supporting high availability for network applications, Which will greatly increase the high availability of network applications. Then we elaborated on heartbeat or service detect, fail-over, service take-over, switchback and error recovery process of the model. In the process of constructing the communication link, we implemented the link management and service take-over with high availability requirement, and discussed the state and the state transition of building the communication link between the hosts, depicted the message transfer and the start of timer. At Last, we applied the designed high availability system to a network billing system, and showed how the system was constructed and implemented, which perfectly satisfied the system requirements. Key words high availability - service take-over - fail-over - communication link management CLC number TP 393 Foundation item: Supported by the National Natural Science Foundation of China (60132030)Biography: Luo Juan (1974-), female, Ph. D candidate, research direction: high speed network and information security.展开更多
基于20kW燃料电池电堆及燃料电池测试系统,获得燃料电池极化曲线及氢气消耗量曲线;基于锂离子动力电池充放电系统,获得锂离子动力电池输出电压曲线.将试验所得数据导入到LMS AMESim软件中,分别构建燃料电池及锂离子动力电池模块,同时,...基于20kW燃料电池电堆及燃料电池测试系统,获得燃料电池极化曲线及氢气消耗量曲线;基于锂离子动力电池充放电系统,获得锂离子动力电池输出电压曲线.将试验所得数据导入到LMS AMESim软件中,分别构建燃料电池及锂离子动力电池模块,同时,构建仿真平台其他所需模块并搭建DC/DC变换器模型,建立燃料电池-锂离子动力电池混合的动力系统仿真平台.依据不同动力源的各自特点,引入能量控制策略,对该混合动力系统进行模拟仿真.在所选定新欧洲驾驶循环(new European driving cycle,NEDC)工况下仿真结果表明,该混合动力系统可以满足车辆在所选定工况下的动力需求.DC/DC变换器可提升并稳定燃料电池输出电压跟随母线电压,并通过对电流的分配进行功率在不同动力源之间的分配;燃料电池输出功率在合理范围之内,并取消燃料电池在低功率下的工况,从而保护燃料电池,延长其使用寿命;锂离子动力电池荷电状态(state of charge,SOC)始终保持在合理范围内,未出现过充或过放情况.研究结果可为搭建混合动力试验平台及整车搭载匹配提供理论依据及参考.展开更多
In term of the features of 3G system, a novel AMR link adaptation strategy for 3G system is proposed. The impacts of AMR codec modes and power control on traffic quality of service are taken into account in the strate...In term of the features of 3G system, a novel AMR link adaptation strategy for 3G system is proposed. The impacts of AMR codec modes and power control on traffic quality of service are taken into account in the strategy at the same time. By synthetically comparing the signal-to-interference ratio value with the switching threshold and comparing the transmission power with its threshold, radio resource management can always keep each link on its proper codec mode with the corresponding optimal power level to achieve both robust speech quality and link capacity enhancement. Based on the WCDMA FDD uplink link-level simulation platform, AMR link adaptation platform is constructed. Simulation results show that the algorithm can track the fast change of channel conditions and select the most robust codec mode, thus the synthetic speech quality of AMR is better than that of signal mode during a wide range of channel conditions. The result will provide a reference strategy for AMR link adaptation of 3G system.展开更多
Based on the research of the Forest Burning Links published in the Journal of Northeast Forestry University in 1987, this paper continues to study the theory of forest burning. Fire behavior has been divided into two ...Based on the research of the Forest Burning Links published in the Journal of Northeast Forestry University in 1987, this paper continues to study the theory of forest burning. Fire behavior has been divided into two important series in this paper. One is fire occurrence and spread, and the other is burning intensity. The first series has been divided into three grades as A: to burn difficulty and spread slowly; B: to burn possibly and spread little fast; and C: to burn easily and spread fast. The second series has been divided into four grades as Ⅰ: light burning; Ⅱ: medium burning; Ⅲ: intense burning; and Ⅳ: severe burning. The first series can be put as ordinate, and the second series can be put as abscissa. Then the network of 12 forest burning links can be formed. In the network, the relationship, the law of distribution and the variation of different forest burning links can be shown clearly. The studies of the distribution of fuel types, topography, site and fire kinds in the network can provide the basic theory for fire management.展开更多
This paper presents a review of the literature on the effectiveness of Blackboard system, its uses and limitations in information management and highlights the ongoing debate of it. A critical evaluation of Blackboard...This paper presents a review of the literature on the effectiveness of Blackboard system, its uses and limitations in information management and highlights the ongoing debate of it. A critical evaluation of Blackboard system literature reveals a good number of academic views, studies, theories, models and experiences regarding the virtual learning environment. The extant literature shows that the world of information management is always in flux as it is being impacted on by the learning technology such as blackboard system. Blackboard system now has a recognised presence in the information management of the education system. Now the question is: how effective is this Blackboard system? The article will explore, in part, how blackboard is designed as suitable learning models in terms of learner cognitive engagement and constructivist perspective, resulting in the effective Blackboard system. It will further cover to review the effectiveness of Blackboard as an aid to pedagogy. Finally, the article will also present a comparison between Blackboard and other LMS such as Moodle to explore the effectiveness and limitations of the Blackboard for better academic information management.展开更多
An analysis and control approach is presented for the active queue management(AQM) problem in network control system supporting multiple links and heterogeneous sources transmission control protocol(TCP).Using additiv...An analysis and control approach is presented for the active queue management(AQM) problem in network control system supporting multiple links and heterogeneous sources transmission control protocol(TCP).Using additive increase multiplicative decrease(AIMD) model,some studies are carried out on multiple links and heterogeneous sources TCP network control system,and some conditions are derived to ensure the stabilization of the given feedback control system by exploiting a general LyapunovKrasovskii functional and some techniques for time-delay systems.And the controller gain is designed further.A simulation is to be provided to verify the algorithm in the paper.展开更多
As the scale of the power system continues to expand,the environment for power operations becomes more and more complex.Existing risk management and control methods for power operations can only set the same risk dete...As the scale of the power system continues to expand,the environment for power operations becomes more and more complex.Existing risk management and control methods for power operations can only set the same risk detection standard and conduct the risk detection for any scenario indiscriminately.Therefore,more reliable and accurate security control methods are urgently needed.In order to improve the accuracy and reliability of the operation risk management and control method,this paper proposes a method for identifying the key links in the whole process of electric power operation based on the spatiotemporal hybrid convolutional neural network.To provide early warning and control of targeted risks,first,the video stream is framed adaptively according to the pixel changes in the video stream.Then,the optimized MobileNet is used to extract the feature map of the video stream,which contains both time-series and static spatial scene information.The feature maps are combined and non-linearly mapped to realize the identification of dynamic operating scenes.Finally,training samples and test samples are produced by using the whole process image of a power company in Xinjiang as a case study,and the proposed algorithm is compared with the unimproved MobileNet.The experimental results demonstrated that the method proposed in this paper can accurately identify the type and start and end time of each operation link in the whole process of electric power operation,and has good real-time performance.The average accuracy of the algorithm can reach 87.8%,and the frame rate is 61 frames/s,which is of great significance for improving the reliability and accuracy of security control methods.展开更多
Based on the existed equipment (the power line carrier, optic fiber, twisted pair and wireless apparatus) being used to the same route in the current communication net of distribution management system (DMS), this pap...Based on the existed equipment (the power line carrier, optic fiber, twisted pair and wireless apparatus) being used to the same route in the current communication net of distribution management system (DMS), this paper presents a new kind of communication monitor DMS, which provides a communication monitoring interface and then by DMS, data transfer problem from field terminal unit to junction center station can be solved and the communication channels can also be supervised. At the same time, synthetically using computer communication, internet technology and database technology, this system can realize the real time monitoring and fault locating in the communication network.展开更多
According to the current problems of higher education management informatization,this paper puts forward a development scheme of collaborative platform on education management.The main technology includes three parts...According to the current problems of higher education management informatization,this paper puts forward a development scheme of collaborative platform on education management.The main technology includes three parts.First,integrate the distributed database and use two-tier linked list to realize dynamic data access.Second,the relation graph is used to display the data of each student,so as to realize the visual sharing of data.Third,realize the collaborative information security mechanism from three aspects to ensure the legal sharing of data.Finally,the platform development is completed with Java.It can help to improve the effectiveness of educating students.展开更多
文摘Despite the rapid evolution in all aspects of computer technology, both the computer hardware and software are prone to numerous failure conditions. In this paper, we analyzed the characteristic of a computer system and the methods of constructing a system, proposed a communication link management model supporting high availability for network applications, Which will greatly increase the high availability of network applications. Then we elaborated on heartbeat or service detect, fail-over, service take-over, switchback and error recovery process of the model. In the process of constructing the communication link, we implemented the link management and service take-over with high availability requirement, and discussed the state and the state transition of building the communication link between the hosts, depicted the message transfer and the start of timer. At Last, we applied the designed high availability system to a network billing system, and showed how the system was constructed and implemented, which perfectly satisfied the system requirements. Key words high availability - service take-over - fail-over - communication link management CLC number TP 393 Foundation item: Supported by the National Natural Science Foundation of China (60132030)Biography: Luo Juan (1974-), female, Ph. D candidate, research direction: high speed network and information security.
文摘基于20kW燃料电池电堆及燃料电池测试系统,获得燃料电池极化曲线及氢气消耗量曲线;基于锂离子动力电池充放电系统,获得锂离子动力电池输出电压曲线.将试验所得数据导入到LMS AMESim软件中,分别构建燃料电池及锂离子动力电池模块,同时,构建仿真平台其他所需模块并搭建DC/DC变换器模型,建立燃料电池-锂离子动力电池混合的动力系统仿真平台.依据不同动力源的各自特点,引入能量控制策略,对该混合动力系统进行模拟仿真.在所选定新欧洲驾驶循环(new European driving cycle,NEDC)工况下仿真结果表明,该混合动力系统可以满足车辆在所选定工况下的动力需求.DC/DC变换器可提升并稳定燃料电池输出电压跟随母线电压,并通过对电流的分配进行功率在不同动力源之间的分配;燃料电池输出功率在合理范围之内,并取消燃料电池在低功率下的工况,从而保护燃料电池,延长其使用寿命;锂离子动力电池荷电状态(state of charge,SOC)始终保持在合理范围内,未出现过充或过放情况.研究结果可为搭建混合动力试验平台及整车搭载匹配提供理论依据及参考.
文摘In term of the features of 3G system, a novel AMR link adaptation strategy for 3G system is proposed. The impacts of AMR codec modes and power control on traffic quality of service are taken into account in the strategy at the same time. By synthetically comparing the signal-to-interference ratio value with the switching threshold and comparing the transmission power with its threshold, radio resource management can always keep each link on its proper codec mode with the corresponding optimal power level to achieve both robust speech quality and link capacity enhancement. Based on the WCDMA FDD uplink link-level simulation platform, AMR link adaptation platform is constructed. Simulation results show that the algorithm can track the fast change of channel conditions and select the most robust codec mode, thus the synthetic speech quality of AMR is better than that of signal mode during a wide range of channel conditions. The result will provide a reference strategy for AMR link adaptation of 3G system.
文摘Based on the research of the Forest Burning Links published in the Journal of Northeast Forestry University in 1987, this paper continues to study the theory of forest burning. Fire behavior has been divided into two important series in this paper. One is fire occurrence and spread, and the other is burning intensity. The first series has been divided into three grades as A: to burn difficulty and spread slowly; B: to burn possibly and spread little fast; and C: to burn easily and spread fast. The second series has been divided into four grades as Ⅰ: light burning; Ⅱ: medium burning; Ⅲ: intense burning; and Ⅳ: severe burning. The first series can be put as ordinate, and the second series can be put as abscissa. Then the network of 12 forest burning links can be formed. In the network, the relationship, the law of distribution and the variation of different forest burning links can be shown clearly. The studies of the distribution of fuel types, topography, site and fire kinds in the network can provide the basic theory for fire management.
文摘This paper presents a review of the literature on the effectiveness of Blackboard system, its uses and limitations in information management and highlights the ongoing debate of it. A critical evaluation of Blackboard system literature reveals a good number of academic views, studies, theories, models and experiences regarding the virtual learning environment. The extant literature shows that the world of information management is always in flux as it is being impacted on by the learning technology such as blackboard system. Blackboard system now has a recognised presence in the information management of the education system. Now the question is: how effective is this Blackboard system? The article will explore, in part, how blackboard is designed as suitable learning models in terms of learner cognitive engagement and constructivist perspective, resulting in the effective Blackboard system. It will further cover to review the effectiveness of Blackboard as an aid to pedagogy. Finally, the article will also present a comparison between Blackboard and other LMS such as Moodle to explore the effectiveness and limitations of the Blackboard for better academic information management.
基金Fundamental Research Funds for the Central Universities,China(No.3132014092)
文摘An analysis and control approach is presented for the active queue management(AQM) problem in network control system supporting multiple links and heterogeneous sources transmission control protocol(TCP).Using additive increase multiplicative decrease(AIMD) model,some studies are carried out on multiple links and heterogeneous sources TCP network control system,and some conditions are derived to ensure the stabilization of the given feedback control system by exploiting a general LyapunovKrasovskii functional and some techniques for time-delay systems.And the controller gain is designed further.A simulation is to be provided to verify the algorithm in the paper.
基金This paper is supported by the Science and technology projects of Yunnan Province(Grant No.202202AD080004).
文摘As the scale of the power system continues to expand,the environment for power operations becomes more and more complex.Existing risk management and control methods for power operations can only set the same risk detection standard and conduct the risk detection for any scenario indiscriminately.Therefore,more reliable and accurate security control methods are urgently needed.In order to improve the accuracy and reliability of the operation risk management and control method,this paper proposes a method for identifying the key links in the whole process of electric power operation based on the spatiotemporal hybrid convolutional neural network.To provide early warning and control of targeted risks,first,the video stream is framed adaptively according to the pixel changes in the video stream.Then,the optimized MobileNet is used to extract the feature map of the video stream,which contains both time-series and static spatial scene information.The feature maps are combined and non-linearly mapped to realize the identification of dynamic operating scenes.Finally,training samples and test samples are produced by using the whole process image of a power company in Xinjiang as a case study,and the proposed algorithm is compared with the unimproved MobileNet.The experimental results demonstrated that the method proposed in this paper can accurately identify the type and start and end time of each operation link in the whole process of electric power operation,and has good real-time performance.The average accuracy of the algorithm can reach 87.8%,and the frame rate is 61 frames/s,which is of great significance for improving the reliability and accuracy of security control methods.
文摘Based on the existed equipment (the power line carrier, optic fiber, twisted pair and wireless apparatus) being used to the same route in the current communication net of distribution management system (DMS), this paper presents a new kind of communication monitor DMS, which provides a communication monitoring interface and then by DMS, data transfer problem from field terminal unit to junction center station can be solved and the communication channels can also be supervised. At the same time, synthetically using computer communication, internet technology and database technology, this system can realize the real time monitoring and fault locating in the communication network.
基金The authors received a specific funding with No.218051360020XN113 for this study。
文摘According to the current problems of higher education management informatization,this paper puts forward a development scheme of collaborative platform on education management.The main technology includes three parts.First,integrate the distributed database and use two-tier linked list to realize dynamic data access.Second,the relation graph is used to display the data of each student,so as to realize the visual sharing of data.Third,realize the collaborative information security mechanism from three aspects to ensure the legal sharing of data.Finally,the platform development is completed with Java.It can help to improve the effectiveness of educating students.
