A simple optimised search heuristic for the job-shop scheduling problem

This paper presents a simple Optimised Search Heuristic for the Job Shop Scheduling problem that combines a GRASP heuristic with a branch-and-bound algorithm. The proposed method is compared with similar approaches and leads to better results in terms of solution quality and computing times.

Metaheuristics for the bus-driver scheduling problem

We present new metaheuristics for solving real crew scheduling problemsin a public transportation bus company. Since the crews of thesecompanies are drivers, we will designate the problem by the bus-driverscheduling problem. Crew scheduling problems are well known and severalmathematical programming based techniques have been proposed to solvethem, in particular using the set-covering formulation. However, inpractice, there exists the need for improvement in terms of computationalefficiency and capacity of solving large-scale instances. Moreover, thereal bus-driver scheduling problems that we consider can present variantaspects of the set covering, as for example a different objectivefunction, implying that alternative solutions methods have to bedeveloped. We propose metaheuristics based on the following approaches:GRASP (greedy randomized adaptive search procedure), tabu search andgenetic algorithms. These metaheuristics also present some innovationfeatures based on and genetic algorithms. These metaheuristics alsopresent some innovation features based on the structure of the crewscheduling problem, that guide the search efficiently and able them tofind good solutions. Some of these new features can also be applied inthe development of heuristics to other combinatorial optimizationproblems. A summary of computational results with real-data problems ispresented.

Motor Vehicle Crash Fatalities for Week Ending, December 19, 2008

Motor Vehicle Crash Fatalities

Motor Vehicle Crash Fatalities for Week Ending, January 16, 2008

Motor Vehicle Crash Fatalities

Motor Vehicle Crash Fatalities for Week Ending, December 19, 2008

Motor Vehicle Crash Fatalities

Motor Vehicle Crash Fatalities for Week Ending, January 2, 2009

Motor Vehicle Crash Fatalities

Motor Vehicle Crash Fatalities for Week Ending, January 2, 2009

Motor Vehicle Crash Fatalities

Motor Vehicle Crash Fatalities for Week Ending, December 19, 2008

Motor Vehicle Crash Fatalities

Motor Vehicle Crash Fatalities for Week Ending,January 30, 2009

Motor Vehicle Crash Fatalities

Motor Vehicle Crash Fatalities for Week Ending,Year End 2008

Motor Vehicle Crash Fatalities

Motor Vehicle Crash Fatalities for Week Ending, February20, 2009

Motor Vehicle Crash Fatalities

Motor Vehicle Crash Fatalities for Week Ending, February 27, 2009

Motor Vehicle Crash Fatalities

Adaptive dynamics and the implementation problem with complete information

This paper studies the equilibrating process of several implementationmechanisms using naive adaptive dynamics. We show that the dynamics convergeand are stable, for the canonical mechanism of implementation in Nash equilibrium.In this way we cast some doubt on the criticism of ``complexity'' commonlyused against this mechanism. For mechanisms that use more refined equilibrium concepts,the dynamics converge but are not stable. Some papers in the literatureon implementation with refined equilibrium concepts have claimed that themechanisms they propose are ``simple'' and implement ``everything'' (incontrast with the canonical mechanism). The fact that some of these ``simple''mechanisms have unstable equilibria suggests that these statements shouldbe interpreted with some caution.

Motor Vehicle Crash Fatalities for Week Ending, April 17, 2009

Motor Vehicle Crash Fatalities

Motor Vehicle Crash Fatalities for Week Ending, May 8, 2009, 2009

Motor Vehicle Crash Fatalities