Holographic function time

2019 ◽  
Author(s):  
Vitaly Kuyukov
Keyword(s):  

Holographiv function

The two-dimensional wave diffraction problem, acoustic or electromagnetic, in which a pulse of step-function time dependence is diffracted by a resistive half-plane is solved by assuming dynamic similarity in the solution.


Mathematics ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 232 ◽  
Author(s):  
Roberto Ugolotti ◽  
Laura Sani ◽  
Stefano Cagnoni

Properly configuring Evolutionary Algorithms (EAs) is a challenging task made difficult by many different details that affect EAs’ performance, such as the properties of the fitness function, time and computational constraints, and many others. EAs’ meta-optimization methods, in which a metaheuristic is used to tune the parameters of another (lower-level) metaheuristic which optimizes a given target function, most often rely on the optimization of a single property of the lower-level method. In this paper, we show that by using a multi-objective genetic algorithm to tune an EA, it is possible not only to find good parameter sets considering more objectives at the same time but also to derive generalizable results which can provide guidelines for designing EA-based applications. In particular, we present a general framework for multi-objective meta-optimization, to show that “going multi-objective” allows one to generate configurations that, besides optimally fitting an EA to a given problem, also perform well on previously unseen ones.


1984 ◽  
Vol 21 (01) ◽  
pp. 88-97
Author(s):  
Victor Solo

The consistency is developed under mild conditions for the least squares estimator of the parameters of a transfer function time series model.


Author(s):  
Paul R. Van Slooten ◽  
Ravi K. Madabhushi ◽  
John H. Stufflebeam ◽  
Jeffrey Lienau

To achieve ultra-low NOx emissions in practical lean premixed combustors, a uniform spatial and temporal fuel/air distribution is required. In addition the response of the fuel/air premixer to acoustic perturbations plays a central role in the coupling of the combustion and acoustic processes that potentially lead to thermoacoustic instabilities. In this paper, results from the simulation of a fuel/air premixer with and without acoustic forcing are reported. An unsteady Reynolds-Averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) code is used in the simulations and the computed results are compared with data obtained using a synchronous PLIF technique. Planar phase-locked images of the fuel/air distribution during the forcing cycle are measured from which the planar averaged (bulk) fuel/air ratio “signal” is obtained. The fuel/air ratio to velocity transfer function (time delay and magnitude) at a specific forcing frequency is computed corresponding to a given jet-to-air momentum flux ratio. The comparisons between the computed and measured time delays are quite good, while the magnitude comparisons are currently inconclusive.


2019 ◽  
Vol 53 (18) ◽  
pp. 1154-1161 ◽  
Author(s):  
Ciara R Burgi ◽  
Scott Peters ◽  
Clare L Ardern ◽  
John R Magill ◽  
Christina D Gomez ◽  
...  

ObjectiveTo describe the criteria used to clear athletes to return to sport (RTS) following primary ACL reconstruction.DesignScoping review.Data sourcesMEDLINE, Embase, CINAHL and SPORTDiscus electronic databases were searched using keywords related to ACL and RTS.Eligibility criteriaProspective or retrospective studies reporting at least one RTS criterion for athletes who had primary ACL reconstruction with an autograft.ResultsIn total, 209 studies fulfilled the inclusion criteria. RTS criteria were categorised into six domains: time, strength, hop testing, clinical examination, patient-report and performance-based criteria. From the 209 included studies, time was used in 178 studies (85%), and in 88 studies (42%) was the sole RTS criterion. Strength tests were reported in 86 studies (41%). Sixteen different hop tests were used in 31 studies (15%). Clinical examination was used in 54 studies (26%), patient report in 26 studies (12%) and performance-based criteria in 41 studies (20%).SummaryTime and impairment-based measures dominated RTS criteria, despite sport being a complex physical and biopsychosocial activity with demands across all aspects of function. Time was included as a criterion in 85% of studies, and over 80% of studies allowed RTS before 9 months. Whether RTS tests are valid—do they predict successful RTS?—is largely unknown.


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