Stefan Thienel - Academia.edu (original) (raw)
Papers by Stefan Thienel
Algorithmica, 2000
In the late eighties and early nineties, three major exciting new developments and some rami cati... more In the late eighties and early nineties, three major exciting new developments and some rami cations in the computation of minimum capacity cuts occurred and these developments motivated us to evaluate the old and new methods experimentally. We provide a brief overview of the most important algorithms for the minimum capacity cut problem and compare these methods both on problem instances from the literature and on problem instances originating from the solution of the traveling salesman problem by branch-and-cut.
... 92, The C++ programming language (2nd edition Stroustrup - 1991. ... 18, Introduction to AB... more ... 92, The C++ programming language (2nd edition Stroustrup - 1991. ... 18, Introduction to ABACUSA Branch-And-CUt System Jünger, Thienel - 1998. ... 1, Practical problem sovlving with cutting plane algorithms in combinatorial optimization Junger, Reinelt, et al. - 1995. ...
... edges in the complete graph, that are in a one-to-one correspondence with the variables in th... more ... edges in the complete graph, that are in a one-to-one correspondence with the variables in theinteger programming formulation, is quadratic in the ... Moreover, there is a high tendency that good, and in particular optimum, solutions are mainly composed of short edges ...
Operations Research Letters, Mar 1, 1998
We modify the incremental algorithm for computing Voronoi diagrams in theEuclidean metric propose... more We modify the incremental algorithm for computing Voronoi diagrams in theEuclidean metric proposed by Ohya, Iri and Murota [6] in order to obtain analgorithm for computing Voronoi diagrams (resp. Delaunay triangulations) in Manhattanand Maximum metric, that is rather simply to implement. We generalizethe notions of "Voronoi diagram" and "Delaunay triangulation" in such a way thatthese structures still can be computed
Software: Practice and Experience, 2000
... edges in the complete graph, that are in a one-to-one correspondence with the variables in th... more ... edges in the complete graph, that are in a one-to-one correspondence with the variables in theinteger programming formulation, is quadratic in the ... Moreover, there is a high tendency that good, and in particular optimum, solutions are mainly composed of short edges ...
Operations Research Letters, 1998
The software system ABACUS is an object-oriented framework for the implementation of branch-and-c... more The software system ABACUS is an object-oriented framework for the implementation of branch-and-cut and branchand-price algorithms. This paper shows the basics of its application to combinatorial and mixed integer optimization problems.
Mathematical Programming, 2002
This is the first of a series of two papers dedicated to efficient separation heuristics for viol... more This is the first of a series of two papers dedicated to efficient separation heuristics for violated inequalities in the context of solving to optimality instances of the Traveling Salesman Problem via branchand-cut . In this paper we give the basic ideas behind these heuristics and design heuristics for comb separation. The second paper will deal with more complex inequalities such as Clique Tree, Star or Path and Ladder inequalities and give computational results.
… optimization: papers from the …, 1995
... 4. Branch and Cut We will now discuss in detail an algorithmic approach for solving hard comb... more ... 4. Branch and Cut We will now discuss in detail an algorithmic approach for solving hard combina ... subproblem is solved, ie, the solution of the LP-relaxation is a feasible solution of the original ... It consists of trying to solve the current problem by optimizing over LP relaxations that ...
Algorithmica, 2000
In the late eighties and early nineties, three major exciting new developments and some rami cati... more In the late eighties and early nineties, three major exciting new developments and some rami cations in the computation of minimum capacity cuts occurred and these developments motivated us to evaluate the old and new methods experimentally. We provide a brief overview of the most important algorithms for the minimum capacity cut problem and compare these methods both on problem instances from the literature and on problem instances originating from the solution of the traveling salesman problem by branch-and-cut.
ZOR Zeitschrift f�r Operations Research Mathematical Methods of Operations Research, 1994
The determination of true optimum solutions of combinatorial optimization problems is seldomly re... more The determination of true optimum solutions of combinatorial optimization problems is seldomly required in practical applications. The majority of users of optimization software would be satisfied with solutions of guaranteed quality in the sense that it can be proven that the given solution is at most a few percent off an optimum solution. This paper presents a general framework for practical problem solving with emphasis on this aspect. A detailed discussion along with a report about extensive computational experiments is given for the traveling salesman problem.
Algorithmica, 2000
In the late eighties and early nineties, three major exciting new developments and some rami cati... more In the late eighties and early nineties, three major exciting new developments and some rami cations in the computation of minimum capacity cuts occurred and these developments motivated us to evaluate the old and new methods experimentally. We provide a brief overview of the most important algorithms for the minimum capacity cut problem and compare these methods both on problem instances from the literature and on problem instances originating from the solution of the traveling salesman problem by branch-and-cut.
... 92, The C++ programming language (2nd edition Stroustrup - 1991. ... 18, Introduction to AB... more ... 92, The C++ programming language (2nd edition Stroustrup - 1991. ... 18, Introduction to ABACUSA Branch-And-CUt System Jünger, Thienel - 1998. ... 1, Practical problem sovlving with cutting plane algorithms in combinatorial optimization Junger, Reinelt, et al. - 1995. ...
... edges in the complete graph, that are in a one-to-one correspondence with the variables in th... more ... edges in the complete graph, that are in a one-to-one correspondence with the variables in theinteger programming formulation, is quadratic in the ... Moreover, there is a high tendency that good, and in particular optimum, solutions are mainly composed of short edges ...
Operations Research Letters, Mar 1, 1998
We modify the incremental algorithm for computing Voronoi diagrams in theEuclidean metric propose... more We modify the incremental algorithm for computing Voronoi diagrams in theEuclidean metric proposed by Ohya, Iri and Murota [6] in order to obtain analgorithm for computing Voronoi diagrams (resp. Delaunay triangulations) in Manhattanand Maximum metric, that is rather simply to implement. We generalizethe notions of "Voronoi diagram" and "Delaunay triangulation" in such a way thatthese structures still can be computed
Software: Practice and Experience, 2000
... edges in the complete graph, that are in a one-to-one correspondence with the variables in th... more ... edges in the complete graph, that are in a one-to-one correspondence with the variables in theinteger programming formulation, is quadratic in the ... Moreover, there is a high tendency that good, and in particular optimum, solutions are mainly composed of short edges ...
Operations Research Letters, 1998
The software system ABACUS is an object-oriented framework for the implementation of branch-and-c... more The software system ABACUS is an object-oriented framework for the implementation of branch-and-cut and branchand-price algorithms. This paper shows the basics of its application to combinatorial and mixed integer optimization problems.
Mathematical Programming, 2002
This is the first of a series of two papers dedicated to efficient separation heuristics for viol... more This is the first of a series of two papers dedicated to efficient separation heuristics for violated inequalities in the context of solving to optimality instances of the Traveling Salesman Problem via branchand-cut . In this paper we give the basic ideas behind these heuristics and design heuristics for comb separation. The second paper will deal with more complex inequalities such as Clique Tree, Star or Path and Ladder inequalities and give computational results.
… optimization: papers from the …, 1995
... 4. Branch and Cut We will now discuss in detail an algorithmic approach for solving hard comb... more ... 4. Branch and Cut We will now discuss in detail an algorithmic approach for solving hard combina ... subproblem is solved, ie, the solution of the LP-relaxation is a feasible solution of the original ... It consists of trying to solve the current problem by optimizing over LP relaxations that ...
Algorithmica, 2000
In the late eighties and early nineties, three major exciting new developments and some rami cati... more In the late eighties and early nineties, three major exciting new developments and some rami cations in the computation of minimum capacity cuts occurred and these developments motivated us to evaluate the old and new methods experimentally. We provide a brief overview of the most important algorithms for the minimum capacity cut problem and compare these methods both on problem instances from the literature and on problem instances originating from the solution of the traveling salesman problem by branch-and-cut.
ZOR Zeitschrift f�r Operations Research Mathematical Methods of Operations Research, 1994
The determination of true optimum solutions of combinatorial optimization problems is seldomly re... more The determination of true optimum solutions of combinatorial optimization problems is seldomly required in practical applications. The majority of users of optimization software would be satisfied with solutions of guaranteed quality in the sense that it can be proven that the given solution is at most a few percent off an optimum solution. This paper presents a general framework for practical problem solving with emphasis on this aspect. A detailed discussion along with a report about extensive computational experiments is given for the traveling salesman problem.