Hidden Markov Models (HMM) are used in a wide range of artifificial intelligence applications including speech recognition, computer vision, computational biology and fifinance. Estimating an HMM parameters is often addressed via the Baum-Welch algorithm (BWA), but this tends to convergence local optimum model parameters. Therefore, optimizing remains crucial challenging work. In paper, Variabl...

This paper is concerned with the development of a new hybrid metaheuristic approach for solving a practical university course timetabling problem in Vietnam. Our hybrid method is a combination of Harmony Search (HS) algorithm and the Bees algorithm. The proposed method has been tested on 14 real-world data instances and compared with some other metaheurisitic approaches, which are Variable Neig...

Given an undirected weighted graph G = (V,E) with vertex set V, edge set E and weights wi ∈ R associated to V or to E. Minimum weighted k-Cardinality tree problem (k-CARD for short) consists of finding a subtree of G with exactly k edges whose sum of weights is minimum [4]. There are two versions of this problem: vertex-weighted and edge-weighted, if weights to V or to E are associated, respect...

The High School Timetabling Problem consists in assigning timeslots and resources to events, satisfying constraints which heavily depend on the specific institution. This work deals with the problem of the ongoing III International Timetabling Competition (ITC), which includes a diverse set of instances from many educational institutions around the world. We proposed an approach based on Simula...

Given an undirected graph with weights associated with its edges, the degree-constrained minimum spanning tree problem consists in nding a minimum spanning tree of the given graph, subject to constraints on node degrees. We propose a variable neighborhood search heuristic for the degree-constrained minimum spanning tree problem, based on a dynamic neighborhood model and using a variable neighbo...