scholarly journals Estimation of Modelling Parameters for H.263-Quantized Video Traces

2013 ◽  
Vol 2013 ◽  
pp. 1-13
Author(s):  
A. Drigas ◽  
S. Kouremenos

We propose methods for selecting the modelling parameters of H.263-quantized video traffic under two different encoding scenarios. For videos encoded with a constant quantization step (unconstrained), we conclude that a two-parameter power relation holds between the exhibited video bit rate and the quantizer value and that the autocorrelation decay rate remains constant for all cases. On the basis of these results, we propose a generic method for estimating the modelling parameters of unconstrained traffic by means of measuring the statistics of the single “raw” video trace. For rate-controlled video (constrained), we propose an approximate method based on the adjustment of the “shape” parameter of the counterpart—with respect to rate—unconstrained video trace. The convergence of the constructed models is assessed viaq-qplots and queuing simulations. On the assumption that the popular MPEG-4 encoders like XVID, DIVX usually employ identical H.263 quantization and rate control schemes, it is expected that the results of this paper also hold for the MPEG-4 part 2 family.

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1943
Author(s):  
Rosario Balbastre-Soldevila ◽  
Rafael García-Bartual ◽  
Ignacio Andrés-Doménech

The two-parameter gamma function (G2P) design storm is a recent methodology used to obtain synthetic hyetographs especially developed for urban hydrology applications. Further analytical developments on the G2P design storm are presented herein, linking the rainfall convectivity n-index with the shape parameter of the design storm. This step can provide a useful basis for future easy-to-handle rainfall inputs in the context of regional urban drainage studies. A practical application is presented herein for the case of Valencia (Spain), based on high-resolution time series of rainfall intensity. The resulting design storm captures certain internal statistics and features observed in the fine-scale rainfall intensity historical records. On the other hand, a direct, simple method is formulated to derivate the design storm from the intensity–duration–frequency (IDF) curves, making use of the analytical relationship with the n-index.


Author(s):  
Yufan Liu ◽  
Li Yang ◽  
Mai Xu ◽  
Zulin Wang

2014 ◽  
Vol 539 ◽  
pp. 456-459
Author(s):  
Hai Shu Yu ◽  
Yan Hua Yuan

In order to make statistic analysis on lifetime data for web game, the two-parameter Weibull distribution was applied to describe its distribution. The shape parameter and the scale parameter were given by maximum likelihood estimation. When a web game followed Weibull distribution, the lifetime parameters are calculated via Matlab. The results show that the proposed model is appropriate to estimate the web game lifetime.


2004 ◽  
Vol 18 (4) ◽  
pp. 1018-1022 ◽  
Author(s):  
Joyce Tredaway Ducar ◽  
John W. Wilcut ◽  
John S. Richburg

Field studies were conducted in 1992 and 1993 to evaluate imazapic alone and in postemergence (POST) mixtures with atrazine or bentazon for weed control in imidazolinone-resistant corn treated with carbofuran. Nicosulfuron and nicosulfuron plus atrazine also were evaluated. Imazapic at 36 and 72 g ai/ha controlled large crabgrass 85 and 92%, respectively, which was equivalent to control obtained with nicosulfuron plus atrazine. Imazapic at the higher rate controlled large crabgrass better than nicosulfuron alone. Imazapic at 36 and 72 g/ha controlled Texas panicum 88 and 99%, respectively, and at the higher rate control was equivalent to that obtained with nicosulfuron alone or in mixture with atrazine. Imazapic plus bentazon POST controlled Texas panicum less than imazapic at the lower rate applied alone. Redroot pigweed was controlled 100% with all herbicide treatments. Imazapic at either rate alone or in tank mixture with bentazon or atrazine controlled prickly sida >99%, which was superior to control obtained with nicosulfuron or nicosulfuron plus atrazine. Smallflower, entireleaf, ivyleaf, pitted, and tall morningglories were controlled 96% or greater with all herbicide treatments except nicosulfuron alone. Sicklepod control was >88% with all imazapic treatments, whereas control from nicosulfuron alone was 72%. Corn yields were improved by the addition of POST herbicides with no differences among POST herbicide treatments.


2013 ◽  
Vol 75 (1) ◽  
pp. 557-567 ◽  
Author(s):  
Sungkwan Jung ◽  
Jeongman Lee ◽  
Gangminh Lee ◽  
Sung-Yeop Pyun ◽  
Dong-Ho Cho

1990 ◽  
Vol 13 (1) ◽  
pp. 121-127 ◽  
Author(s):  
M. E. Ghitany

This paper considers the Bayesian point estimation of the scale parameter for a two-parameter gamma life-testing model in presence of several outlier observations in the data. The Bayesian analysis is carried out under the assumption of squared error loss function and fixed or random shape parameter.


1972 ◽  
Vol 16 (03) ◽  
pp. 191-204
Author(s):  
Paul S. Granville

Shape parameter differential equations are developed for turbulent boundary layers in pressure gradients incorporating two-parameter velocity profiles. Energy and entrainment methods are included. Shear stress factors are explicitly developed for equilibrium and quasi-equilibrium conditions.


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