scholarly journals An estimation of the p-adic sizes of common zeros of partial derivative polynomials of degree six

2014 ◽  
Author(s):  
S. S. Aminudin ◽  
S. H. Sapar ◽  
K. A. Mohd Atan
2015 ◽  
Author(s):  
Yap Hong Keat ◽  
Kamel Ariffin Mohd Atan ◽  
Siti Hasana Sapar ◽  
Mohamad Rushdan Md Said

2009 ◽  
Vol 05 (03) ◽  
pp. 541-554 ◽  
Author(s):  
S. H. SAPAR ◽  
K. A. MOHD. ATAN

It is known that the value of the exponential sum [Formula: see text] can be derived from the estimate of the cardinality |V|, the number of elements contained in the set [Formula: see text] where [Formula: see text] is the partial derivatives of [Formula: see text] with respect to [Formula: see text]. The cardinality of V in turn can be derived from the p-adic sizes of common zeros of the partial derivatives [Formula: see text]. This paper presents a method of determining the p-adic sizes of the components of (ξ,η) a common root of partial derivative polynomials of f(x,y) in Zp[x,y] of degree five based on the p-adic Newton polyhedron technique associated with the polynomial. The degree five polynomial is of the form f(x,y) = ax5 + bx4y + cx3y2 + sx + ty + k. The estimate obtained is in terms of the p-adic sizes of the coefficients of the dominant terms in f.


2014 ◽  
Author(s):  
Yap Hong Keat ◽  
Kamel Ariffin Mohd Atan ◽  
Siti Hasana Sapar ◽  
Mohamad Rushdan Md Said

2012 ◽  
Author(s):  
S.H. Sapar ◽  
K. A. Mohd. Atan

Katakan x = {xi, x2,...,xn} vektor dalam ruang Zn dengan Z menandakan gelanggang integer dan q integer positif, f polinomial dalam x dengan pekali dalam Z. Hasil tambah eksponen yang disekutukan dengan f ditakrifkan sebagai S (f;q) = exp (2πif (x)/ q) yang dinilaikan bagi semua nilai x di dalam reja lengkap modulo q. Nilai S(f;q) adalah bersandar kepada penganggaran bilangan unsur |V|, yang terdapat dalam set V = {x mod q | fx = 0 mod q} dengan fx menandakan polinomial-polinomial terbitan separa f terhadap x. Untuk menentukan kekardinalan bagi V, maklumat mengenai saiz p-adic pensifar sepunya perlu diperolehi. Makalah ini membincangkan suatu kaedah penentuan saiz p-adic bagi komponen (ξ,η) pensifar sepunya pembezaan separa f(x,y) dalam Zp[x, y] berdarjah lima berasaskan teknik polihedron Newton yang disekutukan dengan polinomial terbabit. Polinomial berdarjah lima yang dipertimbangkan berbentuk f(x,y) = ax5 + bx4y + cx3y2 + dx2y3 + exy4 + my5 + nx + ty + k. Kata kunci: Hasil tambah eksponen, kekardinalan, saiz p–adic, polihedron Newton Let x = {xi, x2,...,xn} be a vector in a space Zn with Z ring of integers and let q be a positive integer, f a polynomial in x with coefficients in Z. The exponential sum associated with f is defined as S (f;q) = exp (2πif (x)/ q) where the sum is taken over a complete set of residues modulo q. The value of S (f;q) has been shown to depend on the estimate of the cardinality | V |, the number of elements contained in the set V = {x mod q | fx = 0 mod q} where fx is the partial derivatives of f with respect to x. To determine the cardinality of V, the information on the p-adic sizes of common zeros of the partial derivatives polynomials need to be obtained. This paper discusses a method of determining the p-adic sizes of the components of (ξ,η) a common root of partial derivative polynomials of f(x, y) in Zp[x, y] of degree five based on the p-adic Newton polyhedron technique associated with the polynomial. The quintic polynomial is of the form f(x,y) = ax5 + bx4y + cx3y2 + dx2y3 + exy4 + my5 + nx + ty + k. Key words: Exponential sums, cardinality, p–adic sizes, Newton polyhedron


2021 ◽  
Vol 11 (7) ◽  
pp. 3010
Author(s):  
Hao Liu ◽  
Xuewei Liu

The lack of an initial condition is one of the major challenges in full-wave-equation depth extrapolation. This initial condition is the vertical partial derivative of the surface wavefield and cannot be provided by the conventional seismic acquisition system. The traditional solution is to use the wavefield value of the surface to calculate the vertical partial derivative by assuming that the surface velocity is constant. However, for seismic exploration on land, the surface velocity is often not uniform. To solve this problem, we propose a new method for calculating the vertical partial derivative from the surface wavefield without making any assumptions about the surface conditions. Based on the calculated derivative, we implemented a depth-extrapolation-based full-wave-equation migration from topography using the direct downward continuation. We tested the imaging performance of our proposed method with several experiments. The results of the Marmousi model experiment show that our proposed method is superior to the conventional reverse time migration (RTM) algorithm in terms of imaging accuracy and amplitude-preserving performance at medium and deep depths. In the Canadian Foothills model experiment, we proved that our method can still accurately image complex structures and maintain amplitude under topographic scenario.


Entropy ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 26
Author(s):  
Young Sik Kim

We investigate the partial derivative approach to the change of scale formula for the functon space integral and we investigate the vector calculus approach to the directional derivative on the function space and prove relationships among the Wiener integral and the Feynman integral about the directional derivative of a Fourier transform.


2014 ◽  
Vol 50 (1) ◽  
pp. 66-72 ◽  
Author(s):  
V. I. Zhegalov ◽  
O. A. Tikhonova
Keyword(s):  

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