Comparison of the difference method and 15 N technique for studying the fate of nitrogen from plant residues in soil

1998 ◽  
Vol 26 (3) ◽  
pp. 164-168 ◽  
Author(s):  
T. A. Breland ◽  
S. Hansen
2017 ◽  
Vol 145 ◽  
pp. 03003
Author(s):  
Victor Pavlyuchenko ◽  
Romen Martirosov ◽  
Natalia Nikolskaya ◽  
Anatoly Erlykin

2012 ◽  
Vol 518-523 ◽  
pp. 2820-2824
Author(s):  
Yi Ni Guo ◽  
Yan Zhang ◽  
Jian Wang ◽  
Ye Huang

The finite difference method that is the finite element method is used to solve the plane continuous problems. In this article, the theory and method of the finite difference method, as well as the application on the boundary problem are introduced. By analyzing the potential flew field equation and liquid diffusion equation, they are discreted using the difference method and the numerical analysis under certain boundary condition is conducted. In air pollution, the smoke in the diffusion is typical planar continuous problems. In this paper, the finite difference method is used to analyse and simulate the spread of the smoke.


2018 ◽  
Author(s):  
Paul D Allison

Standard fixed effects methods presume that effects of variables are symmetric: the effect of increasing a variable is the same as the effect of decreasing that variable but in the opposite direction. This is implausible for many social phenomena. York and Light (2017) showed how to estimate asymmetric models by estimating first-difference regressions in which the difference scores for the predictors are decomposed into positive and negative changes. In this paper, I show that there are several aspects of their method that need improvement. I also develop a data generating model that justifies the first-difference method but can be applied in more general settings. In particular, it can be used to construct asymmetric logistic regression models.


2018 ◽  
Vol 11 (3) ◽  
pp. 18-23 ◽  
Author(s):  
Zhang Xuedong ◽  
◽  
Liu Wenxi ◽  
He Shuguang ◽  
◽  
...  

2000 ◽  
Vol T87 (1) ◽  
pp. 53 ◽  
Author(s):  
B. Loiseau ◽  
T. E. O. Ericson

1977 ◽  
Vol 33 (6) ◽  
pp. 1497-1503
Author(s):  
G. T. Aldoshin ◽  
V. I. Zhuk ◽  
B. �. K�rt ◽  
K. M. Shlyakhtina

1988 ◽  
Vol 37 (3-4) ◽  
pp. 299-306 ◽  
Author(s):  
Gordon Allen

AbstractThe frequency of triplets in the U.S. white population may have reached an all-time low around 1964, at 78 sets per million deliveries. One-fourth of those were monozygotic as estimated by the difference method, or 18% by Bulmer's theoretical model. By 1983 the frequency of triplets had nearly doubled, the increase presumably occurring in dizygotic and trizygotic types. In Belgium most triplet pregnancies now result from artificial induction of ovulation, which is expected to occur mainly in older mothers. In the U.S., however, triplets have increased as much in young mothers as in older mothers, proportionally. This age distribution of the increase may be partly explained by a decrease in parity in older mothers since 1964.


2019 ◽  
Vol 5 ◽  
pp. 237802311982644 ◽  
Author(s):  
Paul D. Allison

Standard fixed-effects methods presume that effects of variables are symmetric: The effect of increasing a variable is the same as the effect of decreasing that variable but in the opposite direction. This is implausible for many social phenomena. York and Light showed how to estimate asymmetric models by estimating first-difference regressions in which the difference scores for the predictors are decomposed into positive and negative changes. In this article, I show that there are several aspects of their method that need improvement. I also develop a data-generating model that justifies the first-difference method but can be applied in more general settings. In particular, it can be used to construct asymmetric logistic regression models.


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