Energy Consumption and Passenger Compensation in Disruption Management

2017 ◽  
Author(s):  
Luis Cadarso ◽  
Ángel Marín
Keyword(s):  
Rail Transport ◽  
Disruption Management ◽  
Speed Profile ◽  
Transport Networks ◽  
Optimal Sequence ◽  
New Approach ◽  
Good Balance ◽  
Realistic Problem ◽  
Problem Instances ◽  
Operating Regimes

A new approach is presented in order to deal with disruptions in rail transport networks. A mathematical model which decides on the speed profile while considering passenger use is presented. The model decides on the optimal sequence of operating regimes and the switching points between them for a range of different circumstances and train types all while considering delays and passenger compensation policies applied by the train operator. Computational tests on realistic problem instances of the Spanish rail operator RENFE are reported. The proposed approach is able to find solutions with a very good balance between various managerial goals.

scholarly journals A new approach for disruption management in airline operations control

AI Matters ◽  
2014 ◽  
Vol 1 (1) ◽  
pp. 15-16
Author(s):  
Antonio J. M. Castro ◽  
Ana Paula Rocha ◽  
Eugénio Oliveira
Keyword(s):  
Disruption Management ◽  
Airline Operations ◽  
New Approach ◽  
Operations Control

scholarly journals Accelerating backtrack search with a best-first-search strategy

2014 ◽  
Vol 24 (4) ◽  
pp. 901-916
Author(s):  
Zoltán Ádám Mann ◽  
Tamás Szép
Keyword(s):  
Search Strategy ◽  
Search Algorithm ◽  
Search Space ◽  
New Approach ◽  
Backtrack Search ◽  
Speed Up ◽  
Hard Problems ◽  
Best First Search ◽  
Problem Instances ◽  
Np Hard Problems

Abstract Backtrack-style exhaustive search algorithms for NP-hard problems tend to have large variance in their runtime. This is because “fortunate” branching decisions can lead to finding a solution quickly, whereas “unfortunate” decisions in another run can lead the algorithm to a region of the search space with no solutions. In the literature, frequent restarting has been suggested as a means to overcome this problem. In this paper, we propose a more sophisticated approach: a best-firstsearch heuristic to quickly move between parts of the search space, always concentrating on the most promising region. We describe how this idea can be efficiently incorporated into a backtrack search algorithm, without sacrificing optimality. Moreover, we demonstrate empirically that, for hard solvable problem instances, the new approach provides significantly higher speed-up than frequent restarting.

ANALYSIS OF GENERIC CYCLOCONVERTER OPERATION WITH INSTANTANEOUS COMMUTATION UNDER TRANSIENT AND STEADY-STATE CONDITIONS

2009 ◽  
Vol 18 (06) ◽  
pp. 1061-1073 ◽  
Author(s):  
INNA KATZ ◽  
ALEXANDER ABRAMOVITZ ◽  
YORAM HOREN ◽  
ALON KUPERMAN ◽  
SVETLANA BRONSHTEIN
Keyword(s):  
Steady State ◽  
Computer Program ◽  
Difference Equations ◽  
Load Current ◽  
New Approach ◽  
Theoretical Predictions ◽  
The Difference ◽  
Operating Regimes ◽  
Good Agreement ◽  
Transient And Steady State

This paper offers a new approach to analyses of cycloconverter operation. The difference equations describing the cycloconverters' transient and steady-state operating regimes are derived. Theoretical predictions were validated by a computer program which calculated the load current of different cycloconverter topologies using the proposed methodology. The calculated and experimental results are compared and found to be in good agreement.

scholarly journals A simulation model of a traction network taking into account the variable resistance of the contact line and a given power profile of the electric vehicle in MatLAB Simulink

2021 ◽  
Vol 2061 (1) ◽  
pp. 012042
Author(s):  
E A Spiridonov ◽  
M A Mayboroda
Keyword(s):  
Initial Data ◽  
Simulation Model ◽  
Contact Line ◽  
Building Blocks ◽  
Rail Transport ◽  
Electric Transport ◽  
Transport Networks ◽  
Traction Network ◽  
Power Profile ◽  
Vehicle Motion

Abstract The article describes an approach to the development of a simulation model of an electric transport traction network, taking into account the change in the resistance of the contact wire when the vehicle is moving. The advantage of the model is that it is executed using the building blocks of Simulink, visually reflects the topology of the traction network, and can be used for modeling both trolleybus and rail transport networks. As the initial data for the model, both standardized drive cycles and experimentally obtained modes of vehicle motion can be used.

scholarly journals Solving the Quality of Service Multicast Tree Problem

2021 ◽  
Vol 33 (2) ◽  
pp. 163-172
Author(s):  
Claudio Enrique Risso-Montaldo ◽  
Franco Rafael Robledo-Amoza ◽  
Sergio Enrique Nesmachnow-Cánovas
Keyword(s):  
Quality Of Service ◽  
Integer Programming ◽  
Mixed Integer Programming ◽  
Multicast Tree ◽  
Mixed Integer ◽  
Programming Formulation ◽  
Integer Programming Formulation ◽  
Realistic Problem ◽  
Problem Instances

This article presents a flow-based mixed integer programming formulation for the Quality of Service Multicast Tree problem. This is a relevant problem related to nowadays telecommunication networksto distribute multimedia over cloud-based Internet systems. To the best of our knowledge, no previous mixed integer programming formulation was proposed for Quality of Service Multicast Tree Problem. Experimental evaluation is performed over a set of realistic problem instances from SteinLib, to prove that standard exact solvers can find solutions to real-world size instances. Exact method is applied for benchmarking the proposed formulations, finding optimal solutions and low feasible-to-optimal gaps in reasonable execution times.

The HGEDA Hybrid Algorithm for OLAP Data Cubes

2011 ◽  
Vol 130-134 ◽  
pp. 3158-3162
Author(s):  
Chen Jia ◽  
Hong Wei Chen
Keyword(s):  
Hybrid Algorithm ◽  
New Approach ◽  
Useful Knowledge ◽  
Estimation Of Distribution ◽  
On Line ◽  
Analytical Processing ◽  
Distribution Algorithms ◽  
Problem Instances ◽  
Original Objective ◽  
Massive Databases

On-Line Analytical Processing (OLAP) tools are frequently used in business, science and health to extract useful knowledge from massive databases. An important and hard optimization problem in OLAP data warehouses is the view selection problem, consisting of selecting a set of aggregate views of the data for speeding up future query processing. In this paper we present a new approach, named HGEDA, which is a new hybrid algorithm based on genetic and estimation of distribution algorithms. The original objective is to get benefits from both approaches. Experimental results show that the HGEDA are competitive with the genetic algorithm on a variety of problem instances, often finding approximate optimal solutions in a reasonable amount of time.

scholarly journals Multiphase Simulated Annealing Based on Boltzmann and Bose-Einstein Distribution Applied to Protein Folding Problem

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Juan Frausto-Solis ◽  
Ernesto Liñán-García ◽  
Juan Paulo Sánchez-Hernández ◽  
J. Javier González-Barbosa ◽  
Carlos González-Flores ◽  
...  
Keyword(s):  
Protein Folding ◽  
Simulated Annealing ◽  
Simulated Annealing Algorithm ◽  
Least Squares Method ◽  
Equilibrium Phase ◽  
Boltzmann Distribution ◽  
New Approach ◽  
Einstein Distribution ◽  
Problem Instances ◽  
Bose Einstein

A new hybrid Multiphase Simulated Annealing Algorithm using Boltzmann and Bose-Einstein distributions (MPSABBE) is proposed. MPSABBE was designed for solving the Protein Folding Problem (PFP) instances. This new approach has four phases: (i) Multiquenching Phase (MQP), (ii) Boltzmann Annealing Phase (BAP), (iii) Bose-Einstein Annealing Phase (BEAP), and (iv) Dynamical Equilibrium Phase (DEP). BAP and BEAP are simulated annealing searching procedures based on Boltzmann and Bose-Einstein distributions, respectively. DEP is also a simulated annealing search procedure, which is applied at the final temperature of the fourth phase, which can be seen as a second Bose-Einstein phase. MQP is a search process that ranges from extremely high to high temperatures, applying a very fast cooling process, and is not very restrictive to accept new solutions. However, BAP and BEAP range from high to low and from low to very low temperatures, respectively. They are more restrictive for accepting new solutions. DEP uses a particular heuristic to detect the stochastic equilibrium by applying a least squares method during its execution. MPSABBE parameters are tuned with an analytical method, which considers the maximal and minimal deterioration of problem instances. MPSABBE was tested with several instances of PFP, showing that the use of both distributions is better than using only the Boltzmann distribution on the classical SA.

scholarly journals The Logistics Infrastructure Network of Belarus and its Universal Applications

2020 ◽  
Vol 51 (51) ◽  
pp. 33-40
Author(s):  
Svetlana Kugan
Keyword(s):  
National Economy ◽  
Rail Transport ◽  
Living Standards ◽  
Innovative Development ◽  
Transport Networks ◽  
Management Tools ◽  
Development Path ◽  
Effective Functioning ◽  
International Linkages ◽  
Infrastructure Network

The effective functioning of logistics infrastructure is a prerequisite for themodernization of a regional and national economy. It is also a prerequisite for the transition to an innovative development path; to include the amelioration of a population’s living standards. The study of historical patterns and characteristics of the development of logistics will allow us to determine the main directions for improving the activities of logistics infrastructure, whilst making recourse to appropriate management tools. The most important element of regional infrastructure is traditionally road and rail transport networks, which can both enhance and facilitate a region’s local and international linkages.

scholarly journals New Approach of Assessing Human Errors in Railways

2018 ◽  
Vol 13 (2) ◽  
pp. 1-17 ◽  
Author(s):  
Habib Hadj-Mabrouk
Keyword(s):  
Cognitive Process ◽  
Human Error ◽  
Rail Transport ◽  
Transport Systems ◽  
Key Factors ◽  
Human Errors ◽  
New Approach ◽  
Railway Safety ◽  
Human Operators ◽  
Technical Failures

Abstract Inspired in particular by the works of Reason and Rasmussen and supported by application examples from the field of railway safety, the human error analysis approach proposed to improve the level of safety of rail transport systems involves three complementary levels. The first level of contextual analysis (before the accident) makes it possible to study the various factors favoring the production of the human error at the origin of the accident. The second cognitive level (during the accident) aims to identify the errors related to the human cognitive process involved in a given situation of insecurity. The third level of behavioral analysis (after the accident) focuses on evaluating the consequences of a wrong action in terms of damage to humans, the environment and the human-machine system. This article proposes an original methodological framework for the analysis, classification and evaluation of human errors involved in the safety of rail transport. The key factors taken into account in the analysis concern not only the inappropriate behavior of human operators involved in railway safety and risk management, but also the technical failures of the transport system and the operating and environmental conditions.

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