Reflection on Business Communication in a “Fishbowl”: Increasing Active Learning and Course Effectiveness While Lowering Disconnection

Active learning is synonymous with learning by doing. Power in learning by doing has been amplified by a Confucian scholar “What I hear, I forget. What I see, I remember. What I do, I understand” (Xunzi, 340- 245 BC). In the business communication class, hearing is less effective than seeing and is less effective than experience. True learning must be active, where students’ experiences produce action and connection to the real-world workplace. This pilot study explores the “Fishbowl” active learning method to teach business communication. This case study is anchored in reflective practice and the theory of learning by doing. Data were collected from instructor reflections and students’ self-report data from class discussions during the spring 2022 semester. Findings indicate that (1) practical class discussions amplify the voices of the students rather than the teacher (2) students are willing to be actively engaged with the content if allowed, (3) asking open-ended, analytical, or opinion questions increase class participation, and (4) effective teaching and learning occurs when instructors engage in reflective practice

The Inverse Eigenvalue Problem of a Graph

Inverse eigenvalue problems appear in various contexts throughout mathematics and engineering, and refer to determining all possible lists of eigenvalues (spectra) for matrices fitting some description. The inverse eigenvalue problem of a graph refers to determining the possible spectra of real symmetric matrices whose pattern of nonzero off-diagonal entries is described by the edges of a given graph (precise definitions of this and other terms are given in the next paragraph). This problem and related variants have been of interest for many years and were originally approached through the study of ordered multiplicity lists.This report resulted from the Banff International Research Station Focused Research Groups and is published as Barrett, Wayne, Steve Butler, Shaun Fallat, H. Tracy Hall, Leslie Hogben, Jephian CH Lin, Bryan Shader, and Michael Young. "The inverse eigenvalue problem of a graph." Banff International Research Station: The Inverse Eigenvalue Problem of a Graph, 2016. Posted with permission.</p

The Enhanced Principal Rank Characteristic Sequence

The enhanced principal rank characteristic sequence (epr-sequence) of a symmetric n×n matrix is a sequence ℓ1ℓ2⋯ℓn where ℓk is A, S, or N according as all, some, or none of its principal minors of order k are nonzero. Such sequences give more information than the (0,1) pr-sequences previously studied (where basically the kth entry is 0 or 1 according as none or at least one of its principal minors of order k is nonzero). Various techniques including the Schur complement are introduced to establish that certain subsequences such as NAN are forbidden in epr-sequences over fields of characteristic not two. Using probabilistic methods over fields of characteristic zero, it is shown that any sequence of As and Ss ending in A is attainable, and any sequence of As and Ss followed by one or more Ns is attainable; additional families of attainable epr-sequences are constructed explicitly by other methods. For real symmetric matrices of orders 2, 3, 4, and 5, all attainable epr-sequences are listed with justifications

The Enhanced Principal Rank Characteristic Sequence for Hermitian Matrices

The enhanced principal rank characteristic sequence (epr-sequence) of an n x n matrix is a sequence l(1) l(2) . . .l(n), where each l(k) is A, S, or N according as all, some, or none of its principal minors of order k are nonzero. There has been substantial work on epr-sequences of symmetric matrices (especially real symmetric matrices) and real skew-symmetric matrices, and incidental remarks have been made about results extending (or not extending) to (complex) Hermitian matrices. A systematic study of epr-sequences of Hermitian matrices is undertaken; the differences with the case of symmetric matrices are quite striking. Various results are established regarding the attainability by Hermitian matrices of epr-sequences that contain two Ns with a gap in between. Hermitian adjacency matrices of mixed graphs that begin with N A N are characterized. All attainable epr-sequences of Hermitian matrices of orders 2, 3, 4, and 5, are listed with justifications

The principal rank characteristic sequence over various fields

Given an n x n matrix, its principal rank characteristic sequence is a sequence of length n+1 of 0s and 1s where, for k = 0, 1, . . . , n, a 1 in the kth position indicates the existence of a principal submatrix of rank k and a 0 indicates the absence of such a submatrix. The principal rank characteristic sequences for symmetric matrices over various fields are investigated, with all such attainable sequences determined for all n over any field with characteristic 2. A complete list of attainable sequences for real symmetric matrices of order 7 is reported

The maximum nullity of a complete subdivision graph is equal to its zero forcing number

Barrett et al. asked in [W. Barrett et al. Minimum rank of edge subdivisions of graphs. Electronic Journal of Linear Algebra, 18:530–563, 2009.], whether the maximum nullity is equal to the zero forcing number for all complete subdivision graphs. We prove that this equality holds. Furthermore, we compute the value of M(F, G̊) = Z(G̊) by introducing the bridge tree of a connected graph. Since this equality is valid for all fields, G ̊ has field independent minimum rank, and we also show that G ̊ has a universally optimal matrix

The Enhanced Principal Rank Characteristic Sequence for Hermitian Matrices

The enhanced principal rank characteristic sequence (epr-sequence) of an n\x n matrix is a sequence $\ell_1 \ell_2 \cdots \ell_n$, where each $\ell_k$ is ${\tt A}$, ${\tt S}$, or ${\tt N}$ according as all, some, or none of its principal minors of order $k$ are nonzero. There has been substantial work on epr-sequences of symmetric matrices (especially real symmetric matrices) and real skew-symmetric matrices, and incidental remarks have been made about results extending (or not extending) to (complex) Hermitian matrices. A systematic study of epr-sequences of Hermitian matrices is undertaken; the differences with the case of symmetric matrices are quite striking. Various results are established regarding the attainability by Hermitian matrices of epr-sequences that contain two ${\tt N}$s with a gap in between. Hermitian adjacency matrices of mixed graphs that begin with ${\tt NAN}$ are characterized. All attainable epr-sequences of Hermitian matrices of orders $2$, $3$, $4$, and $5$, are listed with justifications

The principal rank characteristic sequence over various fields

Given an n × n matrix, its principal rank characteristic sequence is a sequence of length n + 1 of 0s and 1s where, for k = 0, 1,..., n, a 1 in the kth position indicates the existence of a principal submatrix of rank k and a 0 indicates the absence of such a submatrix. The principal rank characteristic sequences for symmetric matrices over various fields are investigated, with all such attainable sequences determined for all n over any field with characteristic 2. A complete list of attainable sequences for real symmetric matrices of order 7 is reported