Fourier component fluctuations of wideband ocean tomography signals: Empirical temporal statistics from AST96

2000 ◽  
Vol 108 (5) ◽  
pp. 2543-2543
Author(s):  
Rex K. Andrew ◽  
Bruce M. Howe ◽  
James A. Mercer
Keyword(s):  
Fourier Component ◽  
Temporal Statistics ◽  
Ocean Tomography

scholarly journals Temporal statistics of residual wavefront variance of an adaptive optics system

2019 ◽  
Vol 21 (12) ◽  
pp. 125606
Author(s):  
Jian Huang ◽  
Hong Zhou ◽  
Jinsheng Yang ◽  
Chao Liu ◽  
Hao Xian
Keyword(s):  
Adaptive Optics ◽  
Temporal Statistics ◽  
Adaptive Optics System

scholarly journals Geographical information system and spatial–temporal statistics for monitoring infectious agents in hospital: a model using Klebsiella pneumoniae complex

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Priscila Pinho da Silva ◽  
Fabiola A. da Silva ◽  
Caio Augusto Santos Rodrigues ◽  
Leonardo Passos Souza ◽  
Elisangela Martins de Lima ◽  
...  
Keyword(s):  
Information System ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Tertiary Hospital ◽  
Physical Structure ◽  
Space Time ◽  
Geographical Information ◽  
Infectious Agents ◽  
Healthcare Associated Infection ◽  
Temporal Statistics

Abstract Background The emergence and spread of antimicrobial resistance and infectious agents have challenged hospitals in recent decades. Our aim was to investigate the circulation of target infectious agents using Geographic Information System (GIS) and spatial–temporal statistics to improve surveillance and control of healthcare-associated infection and of antimicrobial resistance (AMR), using Klebsiella pneumoniae complex as a model. Methods A retrospective study carried out in a 450-bed federal, tertiary hospital, located in Rio de Janeiro. All isolates of K. pneumoniae complex from clinical and surveillance cultures of hospitalized patients between 2014 and 2016, identified by the use of Vitek-2 system (BioMérieux), were extracted from the hospital's microbiology laboratory database. A basic scaled map of the hospital’s physical structure was created in AutoCAD and converted to QGis software (version 2.18). Thereafter, bacteria according to resistance profiles and patients with carbapenem-resistant K. pneumoniae (CRKp) complex were georeferenced by intensive and nonintensive care wards. Space–time permutation probability scan tests were used for cluster signals detection. Results Of the total 759 studied isolates, a significant increase in the resistance profile of K. pneumoniae complex was detected during the studied years. We also identified two space–time clusters affecting adult and paediatric patients harbouring CRKp complex on different floors, unnoticed by regular antimicrobial resistance surveillance. Conclusions In-hospital GIS with space–time statistical analysis can be applied in hospitals. This spatial methodology has the potential to expand and facilitate early detection of hospital outbreaks and may become a new tool in combating AMR or hospital-acquired infection.

Dynamic Buckling of Externally Pressurized Imperfect Cylindrical Shells

1975 ◽  
Vol 42 (2) ◽  
pp. 316-320 ◽  
Author(s):  
D. Lockhart ◽  
J. C. Amazigo
Keyword(s):  
Asymptotic Expression ◽  
Cylindrical Shells ◽  
Simple Relation ◽  
Dynamic Buckling ◽  
Fourier Component ◽  
Buckling Load ◽  
Buckling Mode ◽  
Geometric Imperfections ◽  
Circular Cylindrical Shells ◽  
Step Loading

The dynamic buckling of imperfect finite circular cylindrical shells subjected to suddenly applied and subsequently maintained lateral or hydrostatic pressure is studied using a perturbation method. The geometric imperfections are assumed small but arbitrary. A simple asymptotic expression is obtained for the dynamic buckling load in terms of the amplitude of the Fourier component of the imperfection in the shape of the classical buckling mode. Consequently, for small imperfection, there is a simple relation between the dynamic buckling load under step-loading and the static buckling load. This relation is independent of the shape of the imperfection.

The Optimality of Potential Rescaling Approaches in Land Data Assimilation

2013 ◽  
Vol 14 (2) ◽  
pp. 650-660 ◽  
Author(s):  
M. Tugrul Yilmaz ◽  
Wade T. Crow
Keyword(s):  
Soil Moisture ◽  
Data Assimilation ◽  
Least Squares ◽  
Optimal Solution ◽  
Least Squares Regression ◽  
Linear Least Squares ◽  
Optimal Analysis ◽  
Land Data Assimilation ◽  
Temporal Statistics ◽  
Hydrological Variables

Abstract It is well known that systematic differences exist between modeled and observed realizations of hydrological variables like soil moisture. Prior to data assimilation, these differences must be removed in order to obtain an optimal analysis. A number of rescaling approaches have been proposed for this purpose. These methods include rescaling techniques based on matching sampled temporal statistics, minimizing the least squares distance between observations and models, and the application of triple collocation. Here, the authors evaluate the optimality and relative performances of these rescaling methods both analytically and numerically and find that a triple collocation–based rescaling method results in an optimal solution, whereas variance matching and linear least squares regression approaches result in only approximations to this optimal solution.

A parametric stationarity test with smooth breaks

2018 ◽  
Vol 23 (2) ◽  
Author(s):  
Ching-Chuan Tsong ◽  
Cheng-Feng Lee ◽  
Li Ju Tsai
Keyword(s):  
Small Sample ◽  
Fourier Component ◽  
Deterministic Trend ◽  
Fisher Hypothesis ◽  
Trend Breaks ◽  
Stationarity Test ◽  
Unknown Form ◽  
Small Sample Sizes ◽  
Parametric Adjustment ◽  
Smooth Breaks

Abstract We propose a test to investigate the stationarity null against the unit-root alternative where a Fourier component is employed to approximate nonlinear deterministic trend of unknown form. A parametric adjustment is also adopted to accommodate possible stationary error. The asymptotic distribution of the test under the null is derived, and the asymptotic critical values are tabulated. We also show that it is a consistent test. Even with small sample sizes often encountered in empirical applications, our parametric stationarity test employing Fourier term has good size and power properties when trend breaks are gradual. The validity of the Fisher hypothesis for 15 OECD countries is investigated to illustrate the usefulness of our test.

Comments on Jacobs and Tsakonas: “Propeller Loading-Induced Velocity Field by Means of Unsteady Lifting Surface Theory”

1982 ◽  
Vol 26 (04) ◽  
pp. 266-268
Author(s):  
Theodore R. Goodman
Keyword(s):  
Velocity Field ◽  
Velocity Potential ◽  
Fourier Component ◽  
Surface Theory ◽  
Lifting Surface ◽  
Induced Velocity ◽  
Total Velocity

In the cited paper (2) a formula is given for the lth Fourier component of the velocity potential of an N-bladed propeller [equations (9) and (10) of the paper], (2). The total velocity potential is then, of course, given by the sum of all the components.

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