As one of the most unfavorable factors, chatter will seriously hinder the improvement of production efficiency. The weak chatter identification is an effective method for stable cutting. In this paper, a weak chatter ...
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As one of the most unfavorable factors, chatter will seriously hinder the improvement of production efficiency. The weak chatter identification is an effective method for stable cutting. In this paper, a weak chatter identification method is developed using sparse dictionary on account of the milling dynamic responses. As the bases for chatter identification, chatter frequencies are calculated based on the milling dynamic equations. In order to decrease false alarm rate due to the measured background noise, the noise estimation based filtering is proposed. Besides, in consideration of the parameter uncertainty, an adaptive critical bandwidth analysis is implemented with the developed energy proportion index in case of missed alarm. Then, the sparse dictionary matrix is constructed based on the obtained chatter frequencies and critical bandwidth. Finally, the gradient projection for sparse reconstruction (gpsr) algorithm is adopted for chatter frequencies extraction. The proposed method can decrease the measured background noise, obtain critical chatter band and extract weak chatter frequencies accurately. Experimental results shows that the developed method can be successful in weak chatter identification.
In today's world, with the rise in the count of vehicles and lack of proper navigation, the congestion has become a major problem. In this scenario, VANETs play a very important part in improving the traffic condi...
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In today's world, with the rise in the count of vehicles and lack of proper navigation, the congestion has become a major problem. In this scenario, VANETs play a very important part in improving the traffic condition and also in providing proper navigation. Improved navigation system reduces congestion thereby reducing the possibility of occurrence of accidents. In this research work, we have used a position-based routing protocol i.e., gpsr (Greedy Perimeter Stateless Routing Protocol) to effectively analyze the geographical position of the vehicles in the network and to provide updated navigation information. In this system, we have used a security mechanism to identify valid and invalid messages for secure V2V and V2I communications. This mechanism drops all the invalid messages thereby keeping the VANET secure. It also reduces the possibility of attacks on wireless communications in the VANET. This system has better safety features and network performance compared to other hybrid schemes via NS2 simulation.
The routing protocols in MANETs(( Mobile Ad-hoc Networks), generates high cost as it depends on hop-by-hop routing which unables to provide anonymity protection to source, destination and routes.), ALERT ( Anonymous L...
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ISBN:
(纸本)9781479968183
The routing protocols in MANETs(( Mobile Ad-hoc Networks), generates high cost as it depends on hop-by-hop routing which unables to provide anonymity protection to source, destination and routes.), ALERT ( Anonymous Location-Based Efficient Routing Protocol) routing protocol can be used which portioned the network into hierarchical zone partition and also randomly chooses the nodes as intermediate relay nodes. It also hides the data receiver or initiator between many receivers to strengthen source and destination anonymity protection. Thus it provide thwart against many attacks as it provide anonymity protection to sources, destinations and routes.
The routing protocols in MANETs ((Mobile Ad-hoc Networks), generates high cost as it depends on hop-by-hop routing which unables to provide anonymity protection to source, destination and routes.), ALERT (Anonymous Lo...
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ISBN:
(纸本)9781479968190
The routing protocols in MANETs ((Mobile Ad-hoc Networks), generates high cost as it depends on hop-by-hop routing which unables to provide anonymity protection to source, destination and routes.), ALERT (Anonymous Location-Based Efficient Routing Protocol) routing protocol can be used which portioned the network into hierarchical zone partition and also randomly chooses the nodes as intermediate relay nodes. It also hides the data receiver or initiator between many receivers to strengthen source and destination anonymity protection. Thus it provide thwart against many attacks as it provide anonymity protection to sources, destinations and routes.
An improved gpsr routing algorithm is proposed to resolve the energy sensing problem of gpsr. In order to balance the energy-consumption of nodes, improved gpsr routing algorithm uses node's remnant energy as one ...
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An improved gpsr routing algorithm is proposed to resolve the energy sensing problem of gpsr. In order to balance the energy-consumption of nodes, improved gpsr routing algorithm uses node's remnant energy as one of the key factors to decide next-hop. The improved gpsr routing algorithm keeps the characteristics of gpsr algorithm, such as low complexity, easy realization. Based on NS-2, the performance of improved gpsr routing algorithm is analyzed. Experimental results show that the improved gpsr algorithm can balance the node energy consumption effectively and prolong the time to live of the whole sensor network.
An improved gpsr routing algorithm is proposed to resolve the energy sensing problem of *** order to balance the energy-consumption of nodes,improved gpsr routing algorithm uses node's remnant energy as one of the...
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An improved gpsr routing algorithm is proposed to resolve the energy sensing problem of *** order to balance the energy-consumption of nodes,improved gpsr routing algorithm uses node's remnant energy as one of the key factors to decide *** improved gpsr routing algorithm keeps the characteristics of gpsr algorithm,such as low complexity, easy *** on NS-2,the performance of improved gpsr routing algorithm is *** results show that the improved gpsr algorithm can balance the node energy consumption effectively and prolong the time to live of the whole sensor network.
Compressed sensing (CS) theory has been recently applied in Magnetic Resonance Imaging (MRI) to accelerate the overall imaging process. In the CS implementation, various algorithms have been used to solve the nonlinea...
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ISBN:
(纸本)9781424441242
Compressed sensing (CS) theory has been recently applied in Magnetic Resonance Imaging (MRI) to accelerate the overall imaging process. In the CS implementation, various algorithms have been used to solve the nonlinear equation system for better image quality and reconstruction speed. However, there are no explicit criteria for an optimal CS algorithm selection in the practical MRI application. A systematic and comparative study of those commonly used algorithms is therefore essential for the implementation of CS in MRI. In this work, three typical algorithms, namely, the Gradient Projection For Sparse Reconstruction (gpsr) algorithm, Interior-point algorithm (l(1)_ls), and the Stagewise Orthogonal Matching Pursuit (StOMP) algorithm are compared and investigated in three different imaging scenarios, brain, angiogram and phantom imaging. The algorithms' performances are characterized in terms of image quality and reconstruction speed. The theoretical results show that the performance of the CS algorithms is case sensitive;overall, the StOMP algorithm offers the best solution in imaging quality, while the gpsr algorithm is the most efficient one among the three methods. In the next step, the algorithm performances and characteristics will be experimentally explored. It is hoped that this research will further support the applications of CS in MRI.
A new summation formula based on the orthogonal property of Walsh functions is devised. Using this formula, the k-dimensional discrepancy of the generalized feedback shift register (GFSR) pseudorandom numbers is deriv...
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A new summation formula based on the orthogonal property of Walsh functions is devised. Using this formula, the k-dimensional discrepancy of the generalized feedback shift register (GFSR) pseudorandom numbers is derived. The relation between the discrepancy and k-distribution of GFSR sequences is also obtained. Finally the definition of optimal gpsr pseudorandom number generators is introduced.
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