Gerhard Post

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In this paper we propose a neighbourhood structure based on sequential/cyclic moves and a Cyclic Transfer algorithm for the high school timetabling problem. This method enables execution of complex moves for improving an existing solution, while dealing with the challenge of exploring the neighbourhood efficiently. An improvement graph is used in which(More)
We study finite-dimensional Lie algebras of polynomial vector fields in n variables that contain the vector fields ∂ ∂xi (i = 1, . . . , n) and x1 ∂ ∂x1 +· · ·+xn ∂ ∂xn . We derive some general results on the structure of such Lie algebras, and provide the complete classification in the casesn = 2 and n = 3. Finally we describe a certain construction in(More)
This note is devoted to a more detailed description of one of the five simple exceptional Lie superalgebras of vector fields, cvect(0|3)∗, a subalgebra of vect(4|3). We derive differential equations for its elements, and solve these equations. Hence we get an exact form for the elements of cvect(0|3)∗. Moreover we realize cvect(0|3)∗ by ”glued” pairs of(More)
One hundred eighty male managers participated as age-homogeneous 4-person teams in a validated all-day decision-making simulation. Fifteen teams consisted of 28- to 35-year-old participants (young), 15 teams were in the 45-55 age range (middle-aged), and 15 teams consisted of 65- to 75-year-old (older) persons. More than 40 objective performance measures(More)
We study finite-dimensional Lie algebras L of polynomial vector fields in n variables that contain the vector fields ∂ ∂xi (i = 1, . . . , n) and x1 ∂ ∂x1 + · · · + xn ∂ ∂xn . We show that the maximal ones always contain a semi-simple subalgebra ḡ , such that ∂ ∂xi ∈ ḡ (i = 1, . . . ,m) for an m with 1 ≤ m ≤ n . Moreover a maximal algebra has no trivial(More)
The VeRoLog Solver Challenge 2016–2017 is the third solver challenge facilitated by VeRoLog, the EURO Working Group on Vehicle Routing and Logistics Optimization, and is organized in cooperation with ORTEC B.V. The authors constitute the organizing committee of this challenge, and with this paper they report on the problem and organization of this challenge.