Avi Berman

TL;DR: The main open problems in the theory of copositive and completely positive matrices are described in this paper, with a brief description of the state of the art in each open problem.

TL;DR: For a graph G of order n, the minimum rank of G is defined to be the smallest possible rank over all real symmetric n × n matrices A whose (i, j ) th entry (for i ≠ j ) is nonzero whenever { i, j } is an edge in G and is zero otherwise as discussed by the authors.

TL;DR: An exploratory framework for handling the complexity of students’ mathematical problem posing in small groups is introduced, which supports fine-grained analysis of directly observed problem-posing processes, it has a confluence nature, and it attempts to account for hidden mechanisms involved inStudents’ decision making while posing problems.

TL;DR: In this article, the authors showed that those students who were below sample average at the beginning of the experiment benefited from the heuristically-oriented intervention significantly more than the rest of the students.

TL;DR: In this paper, the authors characterize and interrelate various degrees of stability and semipositivity for real square matrices having nonpositive off-diagonal entries, denoted respectively by A, L, and S.