نتایج جستجو برای: gd majorization

تعداد نتایج: 11675  

In this paper we study the concept of Latin-majorizati-\on. Geometrically this concept is different from other kinds of majorization in some aspects. Since the set of all $x$s Latin-majorized by a fixed $y$ is not convex, but, consists of union of finitely many convex sets. Next, we hint to linear preservers of Latin-majorization on $ mathbb{R}^{n}$ and ${M_{n,m}}$.

Journal: :sahand communications in mathematical analysis 0
mohammad ali hadian nadoshan department of mathematics, vali-e-asr university of rafsanjan, zip code: 7718897111, rafsanjan, iran. hamid reza afshin department of mathematics, vali-e-asr university of rafsanjan, zip code: 7718897111, rafsanjan, iran.

in this paper we study the concept of latin-majorizati-on. geometrically this concept is different from other kinds of majorization in some aspects. since the set of all $x$s latin-majorized by a fixed $y$ is not convex, but, consists of :union: of finitely many convex sets. next, we hint to linear preservers of latin-majorization on $ mathbb{r}^{n}$ and ${m_{n,m}}$.

Journal: :bulletin of the iranian mathematical society 0
a. armandnejad vali-e-asr university of rafsanjan z. mohammadi vali-e-asr university of rafsanjan f. akbarzadeh vali-e-asr university of rafsanjan

let a and b be n × m matrices. the matrix b is said to be g-row majorized (respectively g-column majorized) by a, if every row (respectively column) of b, is g-majorized by the corresponding row (respectively column) of a. in this paper all kinds of g-majorization are studied on mn,m, and the possible structure of their linear preservers will be found. also all linear operators t : mn,m ---> mn...

Journal: :Comp. Opt. and Appl. 2011
Qingna Li Houduo Qi Naihua Xiu

We propose two numerical methods, namely the block relaxation and majorization method, for the problem of nearest correlation matrix with factor structure, which is highly nonconvex. In the block relaxation method, the subproblem is of the standard trust region problem, which is solved by Steighaug’s truncated conjugate gradient method or by the trust region method of [21]. In the majorization ...

1989
Roger A. Horn Yoshihiro Nakamura

We give several criteria that are equivalent to the basic singular value majorization inequality (1.1) that is common to both the usual and Hadamard products. We then use these criteria to give a uniied proof of the basic majorization inequality for both products. Finally, we introduce natural generalizations of the usual and Hadamard products and show that although these generalizations do not...

2004
Anil Menon

Moderated greedy search is based on the idea that it is helpful for greedy search algorithms to make non-optimal choices “once in a while.” This notion can be made precise by using the majorizationtheoretic approach to greedy algorithms. Majorization is the study of pre-orderings induced by doubly stochastic matrices. A majorization operator when applied to a distribution makes it “less unequal...

Journal: :bulletin of the iranian mathematical society 2013
a. armandnejad z. mohammadi f. akbarzadeh

let a and b be n × m matrices. the matrix b is said to be g-row majorized (respectively g-column majorized) by a, if every row (respectively column) of b, is g-majorized by the corresponding row (respectively column) of a. in this paper all kinds of g-majorization are studied on mn,m, and the possible structure of their linear preservers will be found. also all linear operators t : mn,m ---> mn...

Journal: :iranian biomedical journal 0
داریوش شهبازی گهرویی daryoush shahbazi-gahrouei barry j. allen mark williams mark williams barry j. allen

two new potential magnetic resonance imaging contrast agents, gd-hematoporphyrin (gd-h) and gd-tetra-carboranylmethoxyphenyl-porphyrin (gd tcp), were synthesized and applied to nude mice with human melanoma (mm 138) xenografts. these agents showed a high relaxivity because of their greater potential to coordinate water molecules. the reduction of t1 relaxation times of 16 and 21% was observed i...

2008
Barry C. Arnold

The appearance of Marshall and Olkin’s 1979 book on inequalities with special emphasis on majorization generated a surge of interest in potential applications of majorization and Schur convexity in a broad spectrum of fields. After 25 years this continues to be the case. The present article presents a sampling of the diverse areas in which majorization has been found to be useful in the past 25...

2009
Christopher C. Paige Jörg Lampe

Given an approximate invariant subspace we discuss the effectiveness of majorization bounds for assessing the accuracy of the resulting Rayleigh-Ritz approximations to eigenvalues of Hermitian matrices. We derive a slightly stronger result than previously for the approximation of k extreme eigenvalues, and examine some advantages of these majorization bounds compared with classical bounds. From...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید