A speed adjustable scheme based selective encryption control model for large-scale multimedia sensing system under resources constraints

Author(s):  
Chen Xiao ◽  
Tiemeng Li ◽  
Nan Yang ◽  
Lifeng Wang ◽  
Shilong Ma
2018 ◽  
Vol 10 (06) ◽  
pp. 1850062 ◽  
Author(s):  
Xiao-Fei Ma ◽  
Tuan-Jie Li ◽  
Zuo-Wei Wang

The space environments and special mission demands require large-scale and high shape accuracy cable net structures. The vibration control is an essential issue for shape control and performance conservation of large flexible cable net structures. This paper investigates the hybrid active wave/mode control of space prestressed taut cable net structures. First, the traveling wave dynamic model of cable net structures is explored by elemental waveguide and propagation equations of cables together with force balance conditions and compatibility conditions of joints. Then, the active wave control model is established by using the assumption forms of wave controllers to adjust the mechanical boundaries of the controlled joints. Finally, the hybrid active wave/mode control model is proposed by constructing the mapping relationship between wave control force, modal damping and natural frequencies. The proposed control method is verified by a planar cable net structure and the results show that the hybrid active wave/mode control can give a better broadband vibration attenuation performance for space prestressed taut cable net structures.


2014 ◽  
Vol 521 ◽  
pp. 151-156
Author(s):  
Sheng Wei Tang ◽  
Yi Tan ◽  
Juan Liu ◽  
Jian Wei Sun

The fluctuation is an important factor that limits large-scale integration of wind power into power grid. In order to improve penetration level of wind power, the EVs based on V2G are considered to participate in regulating wind power while considering charge-discharge characteristics of EV battery. Thus, in this paper, an optimized EV charge-discharge control model is proposed to reduce output fluctuation of wind power. The Monte-Carlo method is used to simulate the stochastic wind speed based on Weibull probability density function. Finally, Genetic Algorithm (GA) is adopted to solve the problem. Results indicate that the EVs based on V2G can reduce the wind power fluctuation level to some extent, absorbing the wind power surplus and compensating the of wind power shortage.


2007 ◽  
Vol 2007 (0) ◽  
pp. _1A1-G02_1-_1A1-G02_4
Author(s):  
Mitsuji MONTA ◽  
Noriko NISHIZAKI ◽  
Satoshi HAMADA ◽  
Kazuhiko NAMBA ◽  
Jun SUYAMA ◽  
...  

2012 ◽  
Vol 263-266 ◽  
pp. 1600-1604
Author(s):  
Qiang Liu ◽  
Jian Hua Zhang

Role-Based Access Control (RBAC) model is the main-stream access control model. When addressing large-scale and distributed application, the highest Security Administrator(SA) of RBAC model always try to transfer his management authority to his inferior SAs to decrease his workload. However, How to ensure that these inferior SAs perform their management authorities legally is a big problem. Although there are a technology framework of administrative RBAC model, named ARBAC97, the supervise mechanism and audit mechanism on the utilization of transferred authorities is incomplete in RBAC model. In this research, an audit-integrated ARBAC (au-ARBAC) model is presented. In the au-ARBAC model, a right and liability mechanism has been set up, an audit role is defined and auditing permission is assigned to this role. At the same time, we put forwards two types basic audit business: routine audit and accident audit. As to accident audit, a decision process for division of responsibility is designed to clarify the responsibility of wrongdoer SAs. The Au-ARBAC model can help to improve the Consciousness of authorization responsibility and to perform their management authorities responsibly and legally.


Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 303 ◽  
Author(s):  
Sijia Hao ◽  
Rui Song ◽  
Shiwei He ◽  
Zekang Lan

Rescheduling is often needed when trains stay in segments or stations longer than specified in the timetable due to disturbances. Under crowded situations, it is more challenging to return to normal with heavy passenger flow. Considering making a trade-off between passenger loss and operating costs, we present a train regulation combined with a passenger control model by analyzing the interactive relationship between passenger behaviors and train operation. In this paper, we convert the problem into a Markov decision process and then propose the management strategy of regulating the running time and controlling the number of boarding passengers. Owing to the high dimensions of the large-scale problem, we applied the Approximate Dynamic Programming (ADP) approach, which approximates the value function with state features to improve computational efficiency. Finally, we designed three experimental scenarios to verify the effectiveness of our proposed model and approach. The results show that both the proposed model and the approach have a good performance in the cases with different passenger flows and different disturbances.


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