In order to meet the needs of multiple targets over the hemispherical space, and as far as possible to increase the antenna scanning angle range and reduce the side lobe level, a multifaceted Phased array consisting o...
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ISBN:
(数字)9781538674970
ISBN:
(纸本)9781538674987
In order to meet the needs of multiple targets over the hemispherical space, and as far as possible to increase the antenna scanning angle range and reduce the side lobe level, a multifaceted Phased array consisting of 16 antenna arrays has been designed and related parameters are given. Different antenna array resources need to be allocated to different targets, and the backtrackingalgorithm is used to quickly calculate the optimal allocation scheme. Finally, an example is given and an allocation scheme is given to verify the correctness and efficiency of the resource allocation algorithm.
In this paper, we propose a new dynamic adaptive virtual network resource allocation strategy named Adaptive-VNE to deal with the complexity and the inefficiency of resource allocation. The proposal coordinates virtua...
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ISBN:
(纸本)9781467309202
In this paper, we propose a new dynamic adaptive virtual network resource allocation strategy named Adaptive-VNE to deal with the complexity and the inefficiency of resource allocation. The proposal coordinates virtual node and virtual link mapping stages. The main idea behind the proposal is take advantage of unused bandwidth with respect to the occupancy rate of embedded virtual links. Hence, the unused bandwidth will be reassigned to incoming Virtual network requests. To do so, Adaptive-VNE adopts the "divide and conquer" strategy. It divides the virtual network request topology into many star topologies. Then, the mapping of each piece within the whole topology is formulated as a if-supplier problem and resolved by an approximation bottleneck algorithm. To generate the global virtual network topology, Adaptive-VNE uses a backtrackingalgorithm in order to minimise the global mapping cost. Note that the proposal forecasts usage rate of virtual links and adapts their bandwidth reservation. Adaptive-VNE was validated by simulations and compared to the related strategies found in literature. The results obtained show that, contrarily to static bandwidth allocation approaches, the adaptive strategy maximises substrate bandwidth usage while the virtual links' bottleneck rate is minimised. Moreover, the congestion periods are minimised and during the bottleneck the bandwidth satisfaction is maximised. Finally, Adaptive-VNE improves performances in terms of acceptance rate of virtual networks and revenue of infrastructure providers.
backtracking is typically used in PV systems which employ single axis tracking to reduce the performance losses that would result from row to row shading if optimal tilt angles were used at all times. Although a backt...
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ISBN:
(数字)9781728126586
ISBN:
(纸本)9781728126593
backtracking is typically used in PV systems which employ single axis tracking to reduce the performance losses that would result from row to row shading if optimal tilt angles were used at all times. Although a backtrackingalgorithm to eliminate shading is straightforward in theory, it becomes more complex in real world installations. This paper will demonstrate the advantages in energy generation that can be achieved by using half cut cell modules as opposed to standard full cell modules when a more complex terrain causes shading on adjacent rows in the morning or evening. It is shown that arrays that use half cut cell modules produce significantly more energy than full cell modules when exposed to a backtracking error that causes minimal shading in a large proportion of the strings connected to a particular inverter.
This paper presents experimental results obtained from a test-bed with IEEE 802.11p modern prototypes and an RF channel emulator, and compares them with simulation results. Measurement results confirm some of the simu...
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ISBN:
(纸本)9781467321877
This paper presents experimental results obtained from a test-bed with IEEE 802.11p modern prototypes and an RF channel emulator, and compares them with simulation results. Measurement results confirm some of the simulation results, and highlight the importance of using channel trackingalgorithms at the receiver to support very high mobility.
Mobile robots need to explore novel environments to build useful maps for later navigation and motion planning. Sensor-based Random Tree, (SRT), technique had been used for exploration but it is problematic since the ...
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ISBN:
(纸本)9781479905874
Mobile robots need to explore novel environments to build useful maps for later navigation and motion planning. Sensor-based Random Tree, (SRT), technique had been used for exploration but it is problematic since the robot may visit the same place more than one time during backtracking process. In this paper, we propose a new heuristic algorithm to reduce this backtracking problem using the obtained map data. This algorithm is tested through computer simulations for several scenarios. The performance is evaluated in terms of exploration time, travelled distance and number of visited nodes. Since these classical evaluation metrics are correlated, we propose a new evaluation metric, that combines the total performance. The new algorithm is confirmed to reduce the exploration time of up to 30%. The new evaluation metric is also shown to encapsulate the exploration performance and can be regarded as a much better representative of the performance that facilitate comparisons.
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