eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
0
0
10.4230/OASIcs.ATMOS.2016
article
OASIcs, Volume 54, ATMOS'16, Complete Volume
Goerigk, Marc
Werneck, Renato
OASIcs, Volume 54, ATMOS'16, Complete Volume
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016/OASIcs.ATMOS.2016.pdf
Analysis of Algorithms and Problem Complexity, Optimization, Combinatorics, Graph Theory, Applications
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
0:i
0:x
10.4230/OASIcs.ATMOS.2016.0
article
Front Matter, Table of Contents, Preface, Organization
Goerigk, Marc
Werneck, Renato F.
Front Matter, Table of Contents, Preface, Organization
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.0/OASIcs.ATMOS.2016.0.pdf
Front Matter
Table of Contents
Preface
Organization
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
1:1
1:15
10.4230/OASIcs.ATMOS.2016.1
article
A Matching Approach for Periodic Timetabling
Pätzold, Julius
Schöbel, Anita
The periodic event scheduling problem (PESP) is a well studied problem known as intrinsically hard, but with important applications mainly for finding good timetables in public transportation. In this paper we consider PESP in public transportation, but in a reduced version (r-PESP) in which the driving and waiting times of the vehicles are fixed to their lower bounds. This results in a still NP-hard problem which has less variables, since only one variable determines the schedule for a whole line. We propose a formulation for r-PESP which is based on scheduling the lines. This enables us on the one hand to identify a finite candidate set and an exact solution approach. On the other hand, we use this formulation to derive a matching-based heuristic for solving PESP. Our experiments on close to real-world instances from LinTim show that our heuristic is able to compute competitive timetables in a very short runtime.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.1/OASIcs.ATMOS.2016.1.pdf
PESP
Timetabling
Public Transport
Matching
Finite Dominating Set
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
2:1
2:15
10.4230/OASIcs.ATMOS.2016.2
article
Sensitivity Analysis and Coupled Decisions in Passenger Flow-Based Train Dispatching
Lemnian, Martin
Müller-Hannemann, Matthias
Rückert, Ralf
Frequent train delays make passenger-oriented train dispatching a task of high practical relevance. In case of delays, dispatchers have to decide whether trains should wait for one or several delayed feeder trains or should depart on time. To support dispatchers, we have recently introduced the train dispatching framework PANDA (CASPT 2015).
In this paper, we present and evaluate two enhancements which are also of general interest.
First, we study the sensitivity of waiting decisions with respect to the accuracy of passenger flow data. More specifically, we develop an integer linear programming formulation for the following optimization problem: Given a critical transfer, what is the minimum number of passengers we have to add or to subtract from the given passenger flow such that the decision would change from waiting to non-waiting or vice versa?
Based on experiments with realistic passenger flows and delay data from 2015 in Germany, an important empirical finding is that a significant fraction of all decisions is highly sensitive to small changes in passenger flow composition. Hence, very accurate passenger flows are needed in these cases.
Second, we investigate the practical value of more sophisticated simulations. A simple strategy evaluates the effect of a waiting decision of some critical transfer on passenger delay subject to the assumption that all subsequent decisions are taken according to standard waiting time rules, as usually employed by railway companies like Deutsche Bahn. Here we analyze the impact of a higher level of simulation where waiting decisions for a critical transfer are considered jointly with one or more other decisions for subsequent transfers. We learn that such "coupled decisions" lead to improved solution in about 6.3% of all considered cases.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.2/OASIcs.ATMOS.2016.2.pdf
train delays
event-activity model
multi-criteria decisions
passenger flows
sensitivity analysis
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
3:1
3:15
10.4230/OASIcs.ATMOS.2016.3
article
Integrating Passengers' Routes in Periodic Timetabling: A SAT approach
Gattermann, Philine
Großmann, Peter
Nachtigall, Karl
Schöbel, Anita
The periodic event scheduling problem (PESP) is a well studied problem known as intrinsically hard. Its main application is for designing periodic timetables in public transportation. To this end, the passengers' paths are required as input data. This is a drawback since the final paths which are used by the passengers depend on the timetable to be designed. Including the passengers' routing in the PESP hence improves the quality of the resulting timetables. However, this makes PESP even harder.
Formulating the PESP as satisfiability problem and using SAT solvers for its solution has been shown to be a highly promising approach. The goal of this paper is to exploit if SAT solvers can also be used for the problem of integrated timetabling and passenger routing. In our model of the integrated problem we distribute origin-destination (OD) pairs temporally through the network by using time-slices in order to make the resulting model more realistic. We present a formulation of this integrated problem as integer program which we are able to transform to a satisfiability problem. We tested the latter formulation within numerical experiments, which are performed on Germany's long-distance passenger railway network. The computation's analysis in which we compare the integrated approach with the traditional one with fixed passengers' weights, show promising results for future scientific investigations.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.3/OASIcs.ATMOS.2016.3.pdf
PESP
Timetabling
Public Transport
Passengers' Routes
SAT
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
4:1
4:14
10.4230/OASIcs.ATMOS.2016.4
article
Pricing Toll Roads under Uncertainty
Dokka, Trivikram
Zemkoho, Alain
Gupta, Sonali Sen
Nobibon, Fabrice Talla
We study the toll pricing problem when the non-toll costs on the network are not fixed and can vary over time. We assume that users who take their decisions, after the tolls are fixed, have full information of all costs before making their decision. Toll-setter, on the other hand, do not have any information of the future costs on the network. The only information toll-setter have is historical information (sample) of the network costs. In this work we study this problem on parallel networks and networks with few number of paths in single origin-destination setting. We formulate toll-setting problem in this setting as a distributionally robust optimization problem and propose a method to solve to it. We illustrate the usefulness of our approach by doing numerical experiments using a parallel network.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.4/OASIcs.ATMOS.2016.4.pdf
Conditional value at risk
robust optimization
toll pricing
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
5:1
5:14
10.4230/OASIcs.ATMOS.2016.5
article
Scheduling Autonomous Vehicle Platoons Through an Unregulated Intersection
Besa Vial, Juan José
Devanny, William E.
Eppstein, David
Goodrich, Michael T.
We study various versions of the problem of scheduling platoons of autonomous vehicles through an unregulated intersection, where an algorithm must schedule which platoons should wait so that others can go through, so as to minimize the maximum delay for any vehicle. We provide polynomial-time algorithms for constructing such schedules for a k-way merge intersection, for constant k, and for a crossing intersection involving two-way traffic. We also show that the more general problem of scheduling autonomous platoons through an intersection that includes both a k-way merge, for non-constant k, and a crossing of two-way traffic is NP-complete.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.5/OASIcs.ATMOS.2016.5.pdf
autonomous vehicles
platoons
scheduling
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
6:1
6:13
10.4230/OASIcs.ATMOS.2016.6
article
Multi-Column Generation Model for the Locomotive Assignment Problem
Jaumard, Brigitte
Tian, Huaining
We propose a new decomposition model and a multi-column generation algorithm for solving the Locomotive Assignment Problem (LAP). The decomposition scheme relies on consist configurations, where each configuration is made of a set of trains pulled by the same set of locomotives. We use the concept of conflict graphs in order to reduce the number of trains to be considered in each consist configuration generator problem: this contributes to significantly reduce the fraction of the computational times spent in generating new potential consists. In addition, we define a column generation problem for each set of variables, leading to a multi-column generation process, with different types of columns.
Numerical results, with different numbers of locomotives, are presented on adapted data sets coming from Canada Pacific Railway (CPR). They show that the newly proposed algorithm is able to solve exactly realistic data instances for a timeline spanning up to 6 weeks, in very reasonable computational times.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.6/OASIcs.ATMOS.2016.6.pdf
Railway optimization
Locomotive assignment
Column Generation
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
7:1
7:13
10.4230/OASIcs.ATMOS.2016.7
article
The Maximum Flow Problem for Oriented Flows
Schade, Stanley
Strehler, Martin
In several applications of network flows, additional constraints have to be considered. In this paper, we study flows, where the flow particles have an orientation. For example, cargo containers with doors only on one side and train coaches with 1st and 2nd class compartments have such an orientation. If the end position has a mandatory orientation, not every path from source to sink is feasible for routing or additional transposition maneuvers have to be made. As a result, a source-sink path may visit a certain vertex several times. We describe structural properties of optimal solutions, determine the computational complexity, and present an approach for approximating such flows.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.7/OASIcs.ATMOS.2016.7.pdf
network flow with orientation
graph expansion
approximation
container logistics
train routing
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
8:1
8:16
10.4230/OASIcs.ATMOS.2016.8
article
Optimizing Traffic Signal Timings for Mega Events
Scheffler, Robert
Strehler, Martin
Most approaches for optimizing traffic signal timings deal with the daily traffic. However, there are a few occasional events like football matches or concerts of musicians that lead to exceptional traffic situations. Still, such events occur more or less regularly and place and time are known in advance. Hence, it is possible to anticipate such events with special signal timings. In this paper, we present an extension of a cyclically time-expanded network flow model and a corresponding mixed-integer linear programming formulation for simultaneously optimizing traffic signal timings and traffic assignment for such events. Besides the mathematical analysis of this approach, we demonstrate its capabilities by computing signal timings for a real world scenario.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.8/OASIcs.ATMOS.2016.8.pdf
traffic flow
traffic signal timings
cyclically time-expanded network
mega event
exceptional traffic
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
9:1
9:13
10.4230/OASIcs.ATMOS.2016.9
article
Automatic Design of Aircraft Arrival Routes with Limited Turning Angle
Granberg, Tobias Andersson
Polishchuk, Tatiana
Polishchuk, Valentin
Schmidt, Christiane
We present an application of Integer Programming to the design of arrival routes for aircraft in a Terminal Maneuvering Area (TMA). We generate operationally feasible merge trees of curvature-constrained routes, using two optimization criteria: (1) total length of the tree, and (2) distance flown along the tree paths. The output routes guarantee that the overall traffic pattern in the TMA can be monitored by air traffic controllers; in particular, we keep merge points for arriving aircraft well separated, and we exclude conflicts between arriving and departing aircraft.
We demonstrate the feasibility of our method by experimenting with arrival routes for a runway at Arlanda airport in the Stockholm TMA.
Our approach can easily be extended in several ways, e.g., to ensure that the routes avoid no-fly zones.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.9/OASIcs.ATMOS.2016.9.pdf
Air Traffic Management
Standard Terminal Arrival Routes
Standard Instrument Departures
Integer programming
Turn constraints
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
10:1
10:12
10.4230/OASIcs.ATMOS.2016.10
article
Trip-Based Public Transit Routing Using Condensed Search Trees
Witt, Sascha
We study the problem of planning Pareto-optimal journeys in public transit networks.
Most existing algorithms and speed-up techniques work by computing subjourneys to intermediary stops until the destination is reached.
In contrast, the trip-based model focuses on trips and transfers between them, constructing journeys as a sequence of trips.
In this paper, we develop a speed-up technique for this model inspired by principles behind existing state-of-the-art speed-up techniques, Transfer Patterns and Hub Labelling.
The resulting algorithm allows us to compute Pareto-optimal (with respect to arrival time and number of transfers) 24-hour profiles on very large real-world networks in less than half a millisecond.
Compared to the current state of the art for bicriteria queries on public transit networks, this is up to two orders of magnitude faster, while increasing preprocessing overhead by at most one order of magnitude.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.10/OASIcs.ATMOS.2016.10.pdf
Public Transit
Routing
Public Transport
Route Planning
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
11:1
11:14
10.4230/OASIcs.ATMOS.2016.11
article
Time-Dependent Bi-Objective Itinerary Planning Algorithm: Application in Sea Transportation
Veneti, Aphrodite
Konstantopoulos, Charalampos
Pantziou, Grammati
A special case of the Time-Dependent Shortest Path Problem (TDSPP) is the itinerary planning problem where the objective is to find the shortest path between a source and a destination node which passes through a fixed sequence of intermediate nodes. In this paper, we deviate from the common approach for solving this problem, that is, finding first the shortest paths between successive nodes in the above sequence and then synthesizing the final solution from the solutions of these sub-problems. We propose a more direct approach and solve the problem by a label-setting approach which is able to early prune a lot of partial paths that cannot be part of the optimal solution. In addition, we study a different version of the main problem where it is only required that the solution path should pass through a set of specific nodes irrespectively of the particular order in which these nodes are included in the path. As a case study, we have applied the proposed techniques for solving the itinerary planning of a ship with respect to two conflicting criteria, in the area of the Aegean Sea, Greece. Moreover, the algorithm handles the case that the ship speed is not constant throughout the whole voyage. Specifically, it can be set at a different level each time the ship departs from an intermediate port in order to obtain low cost solutions for the itinerary planning. The experimental results confirm the high performance of the proposed algorithms.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.11/OASIcs.ATMOS.2016.11.pdf
Multi-criteria optimization
Label setting algorithm
Time dependent networks
Travel planning
Itinerary planning
Sea transportation
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Open Access Series in Informatics
2190-6807
2016-08-24
54
12:1
12:15
10.4230/OASIcs.ATMOS.2016.12
article
Solving Time Dependent Shortest Path Problems on Airway Networks Using Super-Optimal Wind
Blanco, Marco
Borndörfer, Ralf
Hoang, Nam-Dung
Kaier, Anton
Schienle, Adam
Schlechte, Thomas
Schlobach, Swen
We study the Flight Planning Problem for a single aircraft, which deals with finding a path of minimal travel time in an airway network. Flight time along arcs is affected by wind speed and direction, which are functions of time. We consider three variants of the problem, which can be modeled as, respectively, a classical shortest path problem in a metric space, a time-dependent shortest path problem with piecewise linear travel time functions, and a time-dependent shortest path problem with piecewise differentiable travel time functions.
The shortest path problem and its time-dependent variant have been extensively studied, in particular, for road networks. Airway networks, however, have different characteristics: the average node degree is higher and shortest paths usually have only few arcs.
We propose A* algorithms for each of the problem variants. In particular, for the third problem, we introduce an application-specific "super-optimal wind" potential function that overestimates optimal wind conditions on each arc, and establish a linear error bound. We compare the performance of our methods with the standard Dijkstra algorithm and the Contraction Hierarchies (CHs)
algorithm. Our computational results on real world instances show that CHs do not perform as well as on road networks. On the other hand, A* guided by our potentials yields very good results. In particular, for the case of piecewise linear travel time functions, we achieve query times about 15 times shorter than CHs.
https://drops.dagstuhl.de/storage/01oasics/oasics-vol054_atmos2016/OASIcs.ATMOS.2016.12/OASIcs.ATMOS.2016.12.pdf
shortest path problem
A*
flight trajectory optimization
preprocessing
contraction hierarchies
time-dependent shortest path problem