A subgraph T of a digraph D is an out-branching if T is an oriented spanning tree with only one vertex of in-degree zero (called the root). The vertices of T of out-degree zero are leaves. In the Directed Max Leaf Problem, we wish to find the maximum number of leaves in an out-branching of a given digraph D (or, to report that D has no out-branching). In the Directed k-Leaf Problem, we are give...

The dependency–based free–word–order parsing algorithm of Covington (1987, 1990, 1992) can be extended to handle partly or completely fixed word order, while preserving its psychologically realistic preference for near attachment. By adding predictivity, this algorithm can be adapted to parse left–branching and right–branching structures in less stack space than center–embedded structures, just...

Branch-and-Bound (B&B) is perhaps the most fundamental algorithm for the global solution of convex Mixed-Integer Nonlinear Programming (MINLP) problems. It is well-known that carrying out branching in a non-simplistic manner can greatly enhance the practicality of B&B in the context of Mixed-Integer Linear Programming (MILP). No detailed study of branching has heretofore been carried out for MI...

A well-known clustering algorithm is K-means. This algorithm, besides advantages such as high speed and ease of employment, suffers from the problem of local optima. In order to overcome this problem, a lot of studies have been done in clustering. This paper presents a hybrid Extended Cuckoo Optimization Algorithm (ECOA) and K-means (K), which is called ECOA-K. The COA algorithm has advantages ...

BACKGROUND GABAergic interneurons regulate the balance and dynamics of neural circuits, in part, by elaborating their strategically placed axon branches that innervate specific cellular and subcellular targets. However, the molecular mechanisms that regulate target-directed GABAergic axon branching are not well understood. RESULTS Here we show that the secreted axon guidance molecule, SEMA3A,...

Bisimulations that abstract from internal computation have proven to be useful for veriication of compositionally deened transition system. In the literature of probabilistic extensions of such transition systems, similar bisimulations are rare. In this paper, we introduce weak bisimulation and branching bisimulation for transition systems where nondeterministic branching is replaced by probabi...

We present and explore the behaviour of a branch-and-bound algorithm for calculating valid bounds on the k-th largest eigenvalue of a symmetric interval matrix. Branching on the interval elements of the matrix takes place in conjunction with the application of Rohn’s method (an interval extension of Weyl’s theorem) in order to obtain valid outer bounds on the eigenvalues. Inner bounds are obtai...

The Directed Maximum Leaf Out-Branching problem is to find an out-branching (i.e. a rooted oriented spanning tree) in a given digraph with the maximum number of leaves. In this paper, we improve known parameterized algorithms and combinatorial bounds on the number of leaves in out-branchings. We show that – every strongly connected digraph D of order n with minimum indegree at least 3 has an ou...