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visits member for 3 years, 3 months
seen Oct 24 at 1:30

Ph.D. in Electrical Engineering. My work involves Mathematics. And I love Mathematics.


Oct
28
awarded  Tumbleweed
Oct
21
revised Maximization over linear surjective mapping of polyhedron
Clarify the indices i and j.
Oct
21
asked Maximization over linear surjective mapping of polyhedron
Sep
24
awarded  Autobiographer
Sep
18
awarded  Popular Question
Jul
2
awarded  Curious
May
3
revised Find $t$ which minimizes $\|A(x+ty)-b\|^2_2$
Changed b to \beta because b is already used.
May
3
revised Find $t$ which minimizes $\|A(x+ty)-b\|^2_2$
Changed b to \beta because b is already used.
May
3
answered Find $t$ which minimizes $\|A(x+ty)-b\|^2_2$
Jan
22
awarded  Popular Question
Oct
2
revised Maximum coordinate of a linear transformation of a vector
added 222 characters in body
Oct
2
comment Maximum coordinate of a linear transformation of a vector
@peterwhy Given $x$, there exists $\max(M x)$, and I want to bound it in terms of $M$ and $x$. For example, using the above bound, I can say that for all $x$ such that $\|x\|_\infty \leq \frac{\alpha}{\|M\|_\infty}$, $\max(M x) \leq \alpha$. But this bound is too conservative.
Oct
2
comment Maximum coordinate of a linear transformation of a vector
$\|M\|_\infty$ is the induced infinity-norm for the matrix $M$. The last inequality is by definition.
Oct
2
asked Maximum coordinate of a linear transformation of a vector
Oct
4
awarded  Yearling
Sep
20
asked Generalization of monotonicity and condition
Aug
29
comment Any notation for sum of $k$ smallest elements of a vector
@DrKW I'm asking for notation that gives the sum of those two entries, i.e. 5. Note that the vector may be unsorted, so [9 3 5 2 8] will give the same answer (5).
Aug
29
asked Any notation for sum of $k$ smallest elements of a vector
Jul
17
accepted Closedness of sets under linear transformation
Jul
17
awarded  Nice Question