A sparse representation-based optimization algorithm for measuring the time delay of pulsar integrated pulse profile

2015 ◽  
Vol 46 ◽  
pp. 94-103 ◽  
Author(s):  
Hang Yu ◽  
Luping Xu ◽  
Dongzhu Feng ◽  
Xiaochuan He ◽  
Xiaoling Ye
Keyword(s):  
Time Delay ◽  
Sparse Representation ◽  
Optimization Algorithm ◽  
Pulse Profile

scholarly journals Performance Analysis of CAT Swarm Optimization Algorithm in Disruption Tolerant Networks

2021 ◽  
Vol 9 ◽  
Author(s):  
Sangeetha R ◽  
◽  
Dr.R. Vijayabhasker ◽  
Keyword(s):  
Time Delay ◽  
Performance Analysis ◽  
Optimization Algorithm ◽  
Packet Loss ◽  
Swarm Optimization ◽  
Disruption Tolerant Networks ◽  
Cat Swarm Optimization ◽  
Long Time ◽  
End To End ◽  
Store And Forward

Disruption tolerant networks (DTN) are networks that provide unguided technologies. Solar technologies and Radio frequencies are used to operate the network. In DTN networks the connectivity does not last for a long time and they do not provide end to end connectivity. Therefore it uses store and forward technique to forward the packets to the destination nodes. When N number of nodes is participating in the network, each node receives packets from the previous node and sends acknowledgment to the sender node. Time delay occurs on receiving and sending acknowledgment continuously. Collision occurs due to the congestion in the network. Due to the irregular connectivity in the network, the compromised nodes try to drop the whole packet or part of the packet. The Blackhole and Greyhole attacks occur due to the packet loss. Optimized algorithm can be used to solve the above attacks. By using CAT Swarm optimization algorithm, the attacks can be prevented and it minimizes the Time delay in delivering the packets.

scholarly journals Improved Joint Optimization Design for Wireless Sensor and Actuator Networks with Time Delay

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lihan Liu ◽  
Yuehui Guo ◽  
Yang Sun ◽  
Zhuwei Wang ◽  
Enchang Sun ◽  
...  
Keyword(s):  
Optimal Control ◽  
Time Delay ◽  
Optimization Algorithm ◽  
Control Strategy ◽  
Optimization Design ◽  
Wireless Sensor ◽  
Joint Optimization ◽  
Recursion Method ◽  
Transmission Path ◽  
Research Activities

With the rapid development of wireless communication technology, the newest development of wireless sensor and actuator networks (WSANs) provides significant potential applications for various real-time scenarios. Currently, extensive research activities have been carried out in the field of efficient resource management and control design. However, the stability of the controlled plant and the efficiency of network resources are rarely considered collaboratively in existing works. In this paper, in order to enhance the control stability and improve the power consumption efficiency for the WSAN, a novel three-step optimization algorithm jointly designing the control strategy and transmission path routing is proposed when the time delay is considered. First, the minimum hop routing algorithm is used to obtain the set of candidate transmission paths. Then, the optimal control signals for each candidate transmission path can be iteratively derived with a backward recursion method. Finally, the best transmission path is determined under the optimal control strategy to achieve the joint optimization design. The effectiveness of the proposed joint optimization algorithm is verified by the simulations of the application in the power grid system.

Fast time-delay measurement for integrated pulsar pulse profiles

2017 ◽  
Vol 89 (2) ◽  
pp. 297-303 ◽  
Author(s):  
Zhiwei Kang ◽  
Xin He ◽  
Jin Liu ◽  
Tianyuan Tao
Keyword(s):  
Correlation Function ◽  
Time Delay ◽  
Cross Correlation ◽  
Fast Time ◽  
Pulse Profile ◽  
Third Order ◽  
Content Type ◽  
The Third ◽  
Delay Measurement ◽  
Time Delay Measurement

Purpose The authors proposed a new method of fast time delay measurement for integrated pulsar pulse profiles in X-ray pulsar-based navigation (XNAV). As a basic observation of exact orientation in XNAV, time of arrival (TOA) can be obtained by time delay measurement of integrated pulsar pulse profiles. Therefore, the main purpose of the paper is to establish a method with fast time delay measurement on the condition of limited spacecraft’s computing resources. Design/methodology/approach Given that the third-order cumulants can suppress the Gaussian noise and reduce calculation to achieve precise and fast positioning in XNAV, the proposed method sets the third-order auto-cumulants of standard pulse profile, the third-order cross-cumulants of the standard and the observed pulse profile as basic variables and uses the cross-correlation function of these two variables to estimate the time delay of integrated pulsar pulse profiles. Findings The proposed method is simple, fast and has high accuracy in time delay measurement for integrated pulsar pulse profiles. The result shows that compared to the bispectrum algorithm, the method improves the precision of the time delay measurement and reduced the computation time significantly as well. Practical implications To improve the performance of time delay estimation in XNAV systems, the authors proposed a novel method for XNAV to achieve precise and fast positioning. Originality/value Compared to the bispectrum algorithm, the proposed method can improve the speed and precision of the TOA’s calculation effectively by using the cross-correlation function of integrated pulsar pulse profile’s third-order cumulants instead of Fourier transform in bispectrum algorithm.

scholarly journals Adaptation of optimization algorithm parameters to reconstruction of chaotic attractor

2015 ◽  
Vol 56 ◽  
Author(s):  
Miglė Drūlytė ◽  
Kristina Lukoševičiūtė ◽  
Erika Mekšunaitė
Keyword(s):  
Time Series ◽  
Time Delay ◽  
Optimization Algorithm ◽  
Search Algorithm ◽  
Cuckoo Search ◽  
Cuckoo Search Algorithm ◽  
Artificial Bee Colony Optimization ◽  
Bee Colony ◽  
Bee Colony Optimization ◽  
Selection Of

Optimal selection of time delay for time series reconstruction is an important problem in time series analysis and forecasting. When reconstructing the time series into phase space with non-uniform time delay, a time delay selection becomes a difficult optimization problem. To solve this problem, this paper presents two optimization algorithms: cuckoo search algorithm and artificial bee colony optimization algorithm.

A Novel Method to Estimate the Unknown Mixing-Matrix for Blind Source Separation

2012 ◽  
Vol 605-607 ◽  
pp. 2206-2210
Author(s):  
Ning Chen ◽  
Hong Yi Zhang
Keyword(s):  
Sparse Representation ◽  
Blind Source Separation ◽  
Membership Function ◽  
Optimization Algorithm ◽  
Source Separation ◽  
Reliable Data ◽  
Mixing Matrix ◽  
Novel Method ◽  
Effectiveness And Efficiency ◽  
The Impact

The blind source separation (BSS) using a two-stage sparse representation approach is discussed in this paper. We presented the algorithm based on linear membership function to estimate the unknown mixing matrix precisely, and then, the optimization algorithm based on integral to get the max value of the function is proposed. Another contribution described in this paper is the discussion of the impact of noise on the estimating the mixing matrix. Given the impact of noise, we set weights to put more emphasis on the more reliable data. Several experiments involving speech signals show the effectiveness and efficiency of this method.

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