This paper aims at solving the Hermitian SDC problem, i.e., that of \textit{simultaneously diagonalizing via $*$-congruence} a collection finitely many (not need pairwise commute) matrices. Theoretically, we provide some equivalent conditions for such matrix can be simultaneously diagonalized $^*$-congruence.% by nonsingular matrix. Interestingly, one leads to existence positive definite soluti...

Some temporal networks, most notably citation networks, are naturally represented as directed acyclic graphs (DAGs). To detect communities in DAGs, we propose a modularity for DAGs by defining an appropriate null model (i.e., randomized network) respecting the order of nodes. We implement a spectral method to approximately maximize the proposed modularity measure and test the method on citation...

The paper investigates the non-symbolic algebraic semantics of the weak bisimulation congruenceson finite pi processes. The weak bisimulation congruences are studied both in the absence and inthe presence of the mismatch operator. Some interesting phenomena about the open congruences arerevealed. Several new tau laws are discovered and their relationship is discussed. The contributi...

OBJECTIVE Research has suggested that congruence between patient characteristics and contextual characteristics is a more robust predictor of outcomes than either patient or context characteristics alone. The goal of the present study was to examine the degree of congruence between patient preferences for the clinical encounter and reports of analogous dimensions of provider behavior and the ef...

Let f be an integer greater than one. We study three progressively finer equivalence relations on closed 3-manifolds generated by Dehn surgery with denominator f : weak f -congruence, f -congruence, and strong f -congruence. If f is odd, weak f -congruence preserves the ring structure on cohomology with Zf -coefficients. We show that strong f -congruence coincides with a relation previously stu...

A subgroup of Γ which contains some principal congruence subgroup is called a congruence subgroup. The level of a congruence subgroup G is the smallest N such that Γ(N) ⊂ G. The literature on congruence subgroups is vast, and the subject remains very active. Rademacher conjectured that there are only finitely many genus 0 congruence subgroups. This problem was studied by Knopp and Newman [Knopp...

We study how modularity of the human brain changes as children develop into adults. Theory suggests that modularity can enhance the response function of a networked system subject to changing external stimuli. Thus, greater cognitive performance might be achieved for more modular neural activity, and modularity might likely increase as children develop. The value of modularity calculated from f...

In 1916 Ramanujan observed a remarkable congruence: τ(n) ≡ σ11(n) mod 691. The modern point of view is to interpret the Ramanujan congruence as a congruence between the Fourier coefficients of the unique normalized cusp form of weight 12 and the Eisenstein series of the same weight modulo the numerator of the Bernoulli number B12. In this paper we give a simple proof of the Ramanujan congruence...

Despite the major role that modularity occupies in computer science all the known results on modular analysis only treat particular problems and there is no general unifying theory In this paper we provide such a general theory of modularity First we study the space of the criteria for modularity the so called modularity space and give results on its complexity Then we introduce the notion of v...