AutoFolio: An Automatically Configured Algorithm Selector (Extended Abstract)

Article in monograph or in proceedingsLeiden Inst Advanced Computer Science

AutoFolio: An Automatically Configured Algorithm Selector (Extended Abstract)

Article in monograph or in proceedingsLeiden Inst Advanced Computer Science

AutoFolio: An Automatically Configured Algorithm Selector (Extended Abstract)

Algorithms and the Foundations of Software technolog

Automatic construction of parallel portfolios via algorithm configuration

FWN – Publicaties zonder aanstelling Universiteit Leide

Statistical comparison of algorithm performance through instance selection

Algorithms and the Foundations of Software technolog

Contingency Plans for Air Traffic Management

Abstract We present two heuristics based on constraint technology that solve the problem of generating air traffic management contingency plans, which are used in the case of a catastrophic infrastructure failure within EUROCONTROL, the European Organisation for the Safety of Air Navigation. Of the heuristics presented, one is based on constraintbased local search and tabu search, and the other one is a constraint programming and large neighbourhood search hybrid algorithm. The heuristics show that it is feasible to automate the development of contingency plans, which is currently done by human experts; this is desirable for several reasons, for example it would allow the contingency plans to be generated with an increased frequency. The generated plans were evaluated, by EUROCONTROL, to be as good as the human-made ones. 1 Air Traffic Management and Contingency Planning Air traffic management (ATM) at EUROCONTROL, the European Organisation for the Safety of Air Navigation, is about managing and ensuring a safe, efficient, and fair flow of air traffic, assuming a negligible amount of side-effects, such as adverse weather conditions. During normal operation, the Central Flow Management Unit (CFMU) of EUROCONTROL uses several stages, each in increasing detail, to satisfy its operational goals: 1. A strategic stage, taking place several months before the day of operation. 2. A pre-tactical stage that starts six days before the day of operation. 3. An online tactical stage during the day of operation. This stage is called the air traffic flow and capacity management (ATFCM) stage [2], and has two main functions: (a) Calculate the demand of each airspace volume using live flight plan information. (b) Adjust the number of allocated departure slots of the involved aerodromes, such that they optimise the objectives defined in the pre-tactical stage. These objectives typically include, but are not limited to, minimising the total flight delay and air volume overload

Energy efficiency and indoor aire quality os seminar rooms in older buildings with and without mechanical ventilation

The present paper reports on an experimental study performed in a seminar room of the University of Luxembourg in a building of the 1970ies without a major renovation. This lecture room is typical for this building period and has a capacity of 60 seats. It is equipped with a mechanical ventilation system that is normally in operation on workdays for 11 hours a day in semester periods (8:00-19:00h), while windows can be opened manually. A Blower-Door-Test revealed that the room is not airtight. During a year, the ventilation system was shut “on” and “off” in periods of some weeks and the consumed final-energy was measured, as well as the indoor climate assessed by physical and psychological measurements. For instance, the measured CO2 concentrations are marginally better with the ventilation system "on", which was not perceived in any way by the occupants during the investigations. It was not possible to properly identify the impact of ventilation on the consumed heat-energy, as the room could not be thermally separated from the rest of the building. But with the system “on” there was a clear increase in consumed primary energy due to the electric consumption of the fans. No relationship between the perceived percentage of dissatisfied and perceived climate could be observed. It is concluded that the typical normal operation modus is questionable for seminar rooms in older buildings with variable occupancy and that a simple shut down or semi-automatic user controlled modus by low-cost retrofit seems advantageous