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On the complexity of distributed BFS in ad hoc networks with non-spontaneous wake-ups

Dariusz Kowalski, Krzysztof Krzywdziński
2013 Discrete Mathematics & Theoretical Computer Science  
Distributed Computing and Networking International audience We study time and message complexity of the problem of building a BFS tree by a spontaneously awaken node in ad hoc network.  ...  We deliver a deterministic distributed solution that trades time for messages, mainly, with time complexity O(D . min(D; n=f(n)) . logD . log n) and with the number of point-to-point messages sent O(n.  ...  Acknowledgments We are grateful to anonymous reviewers, whose comments helped to improve the overall quality of the paper.  ... 
doi:10.46298/dmtcs.622 fatcat:b4mixvoc6rdwzivbrtpzzq3i2i

On the complexity of distributed BFS in ad hoc networks with non-spontaneous wake-ups

Dariusz Kowalski, Krzysztof, Krzywdzi´nski Krzywdzi´nski
2013 Discrete Mathematics and Theoretical Computer Science DMTCS   unpublished
We study time and message complexity of the problem of building a BFS tree by a spontaneously awaken node in ad hoc network.  ...  We deliver a deterministic distributed solution that trades time for messages, mainly, with time complexity O(D · min(D, n/f (n)) · log D · log n) and with the number of point-to-point messages sent O(  ...  Acknowledgments We are grateful to anonymous reviewers, whose comments helped to improve the overall quality of the paper.  ... 
fatcat:nszl32hoerg67dgbycb37kihzm

Wind turbine wake measurement in complex terrain

KS Hansen, GC Larsen, R Menke, N Vasiljevic, N Angelou, J Feng, WJ Zhu, A Vignaroli, W Liu W, C Xu, WZ Shen
2016 Journal of Physics, Conference Series  
SCADA data from a wind farm and high frequency time series measurements obtained with remote scanning systems have been analysed with focus on identification of wind turbine wake properties in complex  ...  In very complex terrain the wake effects are often "overruled" by distortion effects due to the terrain complexity or topology.  ...  Figure 9 shows a similar distribution, but here the wake center clearly is lifted up above the rotor center. These two wake distributions are labelled "DOWN" and "UP" respectively.  ... 
doi:10.1088/1742-6596/753/3/032013 fatcat:ri3lcnagj5an7lrkrknlanx7gq

Page 547 of Journal of Aircraft Vol. 11, Issue 9 [page]

1974 Journal of Aircraft  
Betz Method and Its Extension to Complex Load Distributions Several investigators have attempted to calculate in de- tail the roll-up of the wake behind a wing.*® This is a complex calculation, and most  ...  A method is developed for the calculation of the initial inviscid form of rolled-up wake vortices behind a wing having arbitrary lift distribution.  ... 

Wake-up Algorithm of Wireless Sensor Node Using Geometric Probability
기하학적 확률을 이용한 무선 센서 노드의 웨이크 업 알고리즘 기법

Sung-Yeol Choi, Sang-Choon Kim, Seong Kun Kim, Je-Hoon Lee
2013 Journal of Sensor Science and Technology  
The only one sensor node will be waked-up and it is ready to sense the event occurred uniformly.  ...  However, it should cause the reduction of sensing coverage. This paper presents new wake-up algorithm for reducing energy consumption in complex WSN.  ...  Fig. 5 .Fig. 7 .Fig. 8 . 578 Angle The example of the probability of event occurrence Support node and wake-up nodes.  ... 
doi:10.5369/jsst.2013.22.4.268 fatcat:72fejolbprh4pmnma52un5hqme

Rotor hovering performance using the method of fast free wake analysis

R. H. MILLER
1983 Journal of Aircraft  
distribution depends in part on the time required for the roll-up process to occur.  ...  For simplicity, only one of the series of rings and one cylinder formed by the tip vortex is shown, although others will exist inboard depending on the roll-up schedule assumed.  ... 
doi:10.2514/3.44861 fatcat:34zvnxnqwfcd7kykpgipxg7vhu

Page 257 of Journal of Aircraft Vol. 20, Issue 3 [page]

1983 Journal of Aircraft  
Figure 1 sketches the geometry at the crucial first encounter of a blade with the rolled up tip vortex in the wake.  ...  Miller* Massachusetts Institute of Technology, Cambridge, Massachusetts Experimental investigations have shown that the bound circulation distribution on a rotor blade is critically dependent on the location  ... 

Distributed Wake-Up Scheduling for Energy Saving in Wireless Networks [article]

Francesco De Pellegrini, Karina Gomez, Daniele Miorandi, Imrich Chlamtac
2011 arXiv   pre-print
We demonstrate that the general problem of wake-up times coordination is equivalent to integer factorization and discuss the implications on the design of efficient scheduling algorithms.  ...  We then propose simple polynomial time heuristic algorithms that can be implemented in a distributed fashion and present a message complexity of the order of the number of links in the network.  ...  Alg. 2 reports on the pseudocode of the centralized version of the BFS WAKE-UP algorithm; however, the BFS WAKE-UP algorithm can be easily implemented in a distributed fashion [25] .  ... 
arXiv:1106.1516v1 fatcat:ieu2gwh4mbh65jppyzc6eyftuu

Energy-Efficient Naming in Beeping Networks [article]

Ny Aina Andriambolamalala, Vlady Ravelomanana
2021 arXiv   pre-print
We are particularly interested in optimizing the energy complexity and the running time of algorithms to resolve these problems.  ...  Our contribution is to design randomized algorithms with an optimal running time of O(n log n) and an energy complexity of O(log n) for both the naming and counting problems on single-hop beeping networks  ...  On the other hand, as the adaptation consists of having each node wake up during extra O(log n) time slots, by Theorem 1, our counting algorithm's time complexity is O(n log n), and its energy complexity  ... 
arXiv:2106.03753v2 fatcat:zr4h2lpegnbptc2wrtvcjif3ma

A Low Computational Framework for Testing Wind Farm Controllers

Felipe Novais, David Schlipf, Steffen Raach
2021 Zenodo  
The concept of wind farm control lies on the assumption that neglecting the dynamic interactions between turbines might lead to a sub-optimal state.  ...  In order to achieve the optimal wake steering setting, it is necessary that each turbine has the correct set of demanded yaw misalignment assigned.  ...  ). ➢➢➢ Low-fidelity surrogate wake models ▪ Neglects deep array effects, Coriolis force, complex terrains & etc. ▪ Wind farm control relies on the precision of such models. ➢ Framework based on low-fidelity  ... 
doi:10.5281/zenodo.5008772 fatcat:4je5evtphfhfnmvv5mmrebtige

Unsteady Trailing Vortex Evolution Behind a Wing In Ground Effect

Jinsoo Cho, Cheolheui Han
2005 Journal of Aircraft  
>7° The modeling of the wake behind a complex configuration is important because of the possible adverse effects of the wake on control surfaces.  ...  Figure 7b shows the effect of wing loading on the wake roll- up behavior behind a WIG (h = 0.2).  ... 
doi:10.2514/1.6477 fatcat:fbrv7eiwlvaplorckfltwgm7qu

Experimental Study on Wake Evolution of a 1.5 MW Wind Turbine in a Complex Terrain Wind Farm Based on LiDAR Measurements

Fei Zhao, Yihan Gao, Tengyuan Wang, Jinsha Yuan, Xiaoxia Gao
2020 Sustainability  
The results showed that the existence of wind shear effect causes asymmetric distribution of wind speed in the wake region.  ...  Under two different incoming wake conditions, the influence of wind shear, terrain and incoming wind characteristics on the development trend of wake was analyzed.  ...  However, the above is only a preliminary analysis based on the wake theory that the turbulence intensity in the wake region can speed up the recovery of the wake. In the work of Ishihara et al.  ... 
doi:10.3390/su12062467 fatcat:2gydmxlxobcz5hrp65leuppsz4

Panel/full-span free-wake coupled method for unsteady aerodynamics of helicopter rotor blade

Jianfeng Tan, Haowen Wang
2013 Chinese Journal of Aeronautics  
The unsteady potential-based panel method is used to consider aerodynamics of finite thickness multi-bladed rotors, and the full-span free-wake method is applied to simulating dynamics of rotor wake.  ...  The predicted aerodynamic loads of rotor blades agree well with available measured data and computational fluid dynamics (CFD) results, and the unsteady dynamics of rotor wake is also well simulated.  ...  The roll-up wake on the advancing and retreating side is captured well and wake convection is also observed.  ... 
doi:10.1016/j.cja.2013.04.050 fatcat:yjpmh537wfeq5gtccd6vvqejji

Distributed computing building blocks for rational agents

Yehuda Afek, Yehonatan Ginzberg, Shir Landau Feibish, Moshe Sulamy
2014 Proceedings of the 2014 ACM symposium on Principles of distributed computing - PODC '14  
Given these preferences we construct two basic building blocks for game theoretic distributed algorithms, a wake-up building block resilient to any preference and in particular to the communication preference  ...  We distinguish between different utility functions in the context of distributed algorithms, e.g., utilities based on communication preference, solution preference, and output preference.  ...  Acknowledgments We are grateful to Michal Feldman for helpful discussions and for her enlightening course on Algorithmic Game Theory which has inspired this research, and to Eyal Itkin and the PODC reviewers  ... 
doi:10.1145/2611462.2611481 dblp:conf/podc/AfekGFS13 fatcat:bjehbysbevesrjojwjkmspsxym

Computational methods for wake modeling and blade airload determination in hover and forward flight

R.H. Miller, T.W. Roberts, E.M. Murman
1986 Computers and Mathematics with Applications  
One approach assumes that the wake trailed from the rotor rolls up into discrete vortices according to the Betz criterion for conservation of momentum.  ...  The other approach incorporates the same simplified free wake model of the rotor in a finite difference calculation of the flow field.  ...  The roll-up of the fairly complex blade circulation pattern was therefore approximated by three vortex filaments in the wake.  ... 
doi:10.1016/0898-1221(86)90087-8 fatcat:5xo73n5dibfbbmii2aqmkana24
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