Operations Research

In the widest sense, Operations Research (OR) comprises all techniques and algorithms used to improve the efficiency of systems. It is therefore closely related to optimization and covers areas such as  logistics, packing, and scheduling.

Posts

Publications

• Mingxuan LI (李明轩), Thomas Weise (汤卫思), Sina Abdipoor (سینا عبدی‌پور), Jourdan D'orville, Say Leng Goh, and Razali Yaakob: Integrative Hybrid Local Search with Luby's Restart Strategy for University Course Timetabling with Student Sectioning. 15th Conference on the Practice and Theory of Automated Timetabling (PATAT'2026), August 25-28, 2026, University of Nottingham, UK. Accepted for Publication.
  RLS, local search, scheduling, OR, more infos.
• Thomas Weise (汤卫思), Sina Abdipoor (سینا عبدی‌پور), Mingxuan LI (李明轩), and Zhize WU (吴志泽): Solving the SpOC 4 Challenge 2 with a Multi-Step Permutation Encoding for the Keplerian Traveling Salesperson. Genetic and Evolutionary Computation Conference (GECCO'2026) Companion, July 13-17, 2026, San José, Costa Rica, pages 33–34. New York, NY, USA: ACM.
  space, moptipy, Python, OR, more infos.
• Mingxuan LI (李明轩), Thomas Weise (汤卫思), Sina Abdipoor (سینا عبدی‌پور), and Zhize WU (吴志泽): SpOC 4 Challenges 1 Beginner: Permutation Encodings and Challenge 3: Simulated Annealing for the Luna Tomato Advertising. Genetic and Evolutionary Computation Conference (GECCO'2026) Companion, July 13-17, 2026, San José, Costa Rica, pages 31–32. New York, NY, USA: ACM.
  space, moptipy, Python, OR, more infos.
• Mohammad Ali Raayatpanah (محمدعلی رعایت پناه), Thomas Weise (汤卫思), Jocelyne Elias, Fabio Martignon, and Andrea Pimpinella: Scalable Optimization for Congestion-Aware NFV Deployment. Computer Networks. 281:112216. May 2026.
  distributed systems, OR, more infos.
• Mohammad Ali Raayatpanah (محمدعلی رعایت پناه), Thomas Weise (汤卫思), Jocelyne Elias, Fabio Martignon, and Andrea Pimpinella: A Mixed-Integer Linear Programming Approach for Congestion-Aware Optimized NFV Deployment. 23rd International Symposium on Modeling and Optimization in Mobile, Ad hoc, and Wireless Networks (WiOpt'2025), May 26-29, 2025, Linköping, Sweden. IEEE.
  distributed systems, OR, more infos.
• Rui ZHAO (赵睿), Zhize WU (吴志泽), Daan van den Berg, Matthias Thürer, Tianyu LIANG (梁天宇), Tan MING (檀明), and Thomas Weise (汤卫思): Randomized Local Search for Two-Dimensional Bin Packing and a Negative Result for Frequency Fitness Assignment. International Conference on Evolutionary Computation Theory and Applications (ECTA'2024), part of 16th International Joint Conference on Computational Intelligence (IJCCI'2024), November 20-22, 2024, Porto, Portugal, pages 15–26. Setúbal, Portugal: SciTePress.
  FFA, RLS, FRLS, local search, packing, moptipy, Python, OR, more infos.
• Jiayang CHEN (陈嘉阳), Zhize WU (吴志泽), Sarah Louise Thomson, and Thomas Weise (汤卫思): Frequency Fitness Assignment: Optimization Without Bias for Good Solution Outperforms Randomized Local Search on the Quadratic Assignment Problem. International Conference on Evolutionary Computation Theory and Applications (ECTA'2024), part of 16th International Joint Conference on Computational Intelligence (IJCCI'2024), November 20-22, 2024, Porto, Portugal, pages 27–37. Setúbal, Portugal: SciTePress.
  FFA, QAP, RLS, FRLS, local search, moptipy, Python, OR, more infos.
• Tianyu LIANG (梁天宇), Zhize WU (吴志泽), Matthias Thürer, Markus Wagner, and Thomas Weise (汤卫思): Generating Small Instances with Interesting Features for the Traveling Salesperson Problem. International Conference on Evolutionary Computation Theory and Applications (ECTA'2024), part of 16th International Joint Conference on Computational Intelligence (IJCCI'2024), November 20-22, 2024, Porto, Portugal, pages 173–180. Setúbal, Portugal: SciTePress.
  TSP, logistics, RLS, FFA, local search, moptipy, Python, OR, more infos.
• Xiang CAO (曹翔), Zhize WU (吴志泽), Daan van den Berg, and Thomas Weise (汤卫思): Randomized Local Search vs. NSGA-II vs. Frequency Fitness Assignment on The Traveling Tournament Problem. International Conference on Evolutionary Computation Theory and Applications (ECTA'2024), part of 16th International Joint Conference on Computational Intelligence (IJCCI'2024), November 20-22, 2024, Porto, Portugal, pages 38–49. Setúbal, Portugal: SciTePress.
  TTP, logistics, RLS, FRLS, FFA, local search, moptipy, Python, OR, more infos.
• Sarah Louise Thomson, Gabriela Ochoa, Daan van den Berg, Tianyu LIANG (梁天宇), and Thomas Weise (汤卫思): Entropy, Search Trajectories, and Explainability for Frequency Fitness Assignment. 18th International Conference on Parallel Problem Solving from Nature (PPSN XVIII), September 14-18, 2024, Hagenberg, Austria, pages 377–392. Lecture Notes in Computer Science (LNCS), volume 15148. Berlin/Heidelberg, Germany: Springer.
  QAP, RLS, FRLS, FFA, SA, local search, moptipy, Python, SA, OR, more infos.
• Tianyu LIANG (梁天宇), Zhize WU (吴志泽), Jörg Lässig, Daan van den Berg, Sarah Louise Thomson, and Thomas Weise (汤卫思): Addressing the Traveling Salesperson Problem with Frequency Fitness Assignment and Hybrid Algorithms. Soft Computing 28(17-18):9495–9508. September 2024.
  TSP, logistics, RLS, FFA, local search, SA, moptipy, Python, OR, more infos.
• Rui ZHAO (赵睿), Tianyu LIANG (梁天宇), Zhize WU (吴志泽), Daan van den Berg, Matthias Thürer, and Thomas Weise (汤卫思): Randomized Local Search on the 2D Rectangular Bin Packing Problem with Item Rotation. Genetic and Evolutionary Computation Conference (GECCO'2024) Companion, July 14-18, 2024, Melbourne, VIC, Australia, pages 235–238. New York, NY, USA: ACM.
  RLS, packing, local search, moptipy, Python, OR, more infos.
• Kristian Verduin, Ruben Horn, Okke van Eck, Reitze Jansen, Thomas Weise (汤卫思), and Daan van den Berg: The Traveling Tournament Problem: Rows-First versus Columns-First. 26th International Conference on Enterprise Information Systems (ICEIS'2024), April 28-30, 2024, Angers, France, pages 447–455. Setúbal, Portugal: SciTePress.
  TTP, logistics, GAs, OR, more infos.
• Kristian Verduin, Thomas Weise (汤卫思), and Daan van den Berg: Why is the Traveling Tournament Problem not Solved with Genetic Algorithms? Late-Breaking Abstracts of EvoStar'2023, April 12-14, 2023, Brno, Czech Republic.
  TTP, logistics, GAs, OR, more infos.
• Tianyu LIANG (梁天宇), Zhize WU (吴志泽), Jörg Lässig, Daan van den Berg, and Thomas Weise (汤卫思): Solving the Traveling Salesperson Problem using Frequency Fitness Assignment. IEEE Symposium on Foundations of Computational Intelligence (IEEE FOCI'2022), part of the IEEE Symposium Series on Computational Intelligence (SSCI'2022), December 4-7, 2022, Singapore. IEEE.
  TSP, logistics, FFA, local search, RLS, moptipy, Python, OR, more infos.
• Thomas Weise (汤卫思), Xinlu LI (李新路), Yan CHEN (陈岩), and Zhize WU (吴志泽): Solving Job Shop Scheduling Problems Without Using a Bias for Good Solutions. Genetic and Evolutionary Computation Conference Companion (GECCO'21) Companion, July 10-14, 2021, Lille, France. New York, NY, USA: ACM.
  FFA, local search, aitoa-code, scheduling, OR, more infos.
• Thomas Weise (汤卫思), Yan JIANG (江炎), Qi QI (齐琪), and Weichen LIU (刘伟臣): A Branch-and-Bound-Based Crossover Operator for the Traveling Salesman Problem. International Journal of Cognitive Informatics and Natural Intelligence (IJCINI) 13(3):1-18. Autumn 2019.
  B&B, TSP, logistics, EAs, TSP Suite, OR, more infos.
• Thomas Weise (汤卫思), Yuezhong WU (吴越钟), Weichen LIU (刘伟臣), and Raymond Chiong: Implementation Issues in Optimization Algorithms: Do they matter? Journal of Experimental & Theoretical Artificial Intelligence (JETAI) 31(4):533-554. 2019.
  TSP, logistics, local search, TSP Suite, benchmarking, OR, more infos.
• Thomas Weise (汤卫思), Zijun WU (吴自军), and Markus Wagner: An Improved Generic Bet-and-Run Strategy with Performance Prediction for Stochastic Local Search. 33rd AAAI Conference on Artificial Intelligence (AAAI'2019), January 27 - February 1, 2019, Honolulu, Hawaii, USA, pages 2395–2402. Palo Alto, CA, USA: AAAI Press.
  TSP, logistics, local search, OR, more infos.
• Thomas Weise (汤卫思), Xiao-Feng WANG (王晓峰), Qi QI (齐琪), Bin LI (李斌), and Ke TANG (唐珂): Automatically discovering clusters of algorithm and problem instance behaviors as well as their causes from experimental data, algorithm setups, and instance features. Applied Soft Computing Journal (ASOC), 73:366–382, December 2018.
  TSP, logistics, benchmarking, optimizationBenchmarking, ACO, EAs, local search, Tabu Search, OR, more infos.
• Mohammad Ali Raayatpanah (محمدعلی رعایت پناه) and Thomas Weise (汤卫思): Virtual Network Function Placement for Service Function Chaining with Minimum Energy Consumption. IEEE International Conference on Computer and Communication Engineering Technology (CCET'2018), August 18-20, 2018, Beijing, China, IEEE.
  optimization, OR, more infos.
• Markus Ullrich, Thomas Weise (汤卫思), Abhishek Awasthi, and Jörg Lässig: A Generic Problem Instance Generator for Discrete Optimization Problems. Genetic and Evolutionary Computation Conference (GECCO'2018) Companion, July 15-19, 2018, Kyoto, Japan, pages 1761–1768 New York, NY, USA: ACM.
  benchmarking, TSP, logistics, OR, more infos.
• Qi QI (齐琪), Thomas Weise (汤卫思), and Bin LI (李斌): Optimization Algorithm Behavior Modeling: A Study on the Traveling Salesman Problem. 10th International Conference on Advanced Computational Intelligence (ICACI'2018), March 29-31, 2018, Xiamen, Fujian, China, IEEE, pages 861–866.
  TSP, TSP Suite, logistics, benchmarking, Tabu Search, OR, more infos.
• Thomas Weise (汤卫思): From Standardized Data Formats to Standardized Tools for Optimization Algorithm Benchmarking. 16th IEEE Conference on Cognitive Informatics & Cognitive Computing (ICCI*CC'2017), July 26-28, 2017, University of Oxford, Oxford, UK, pages 490–497. Los Alamitos, CA, USA: IEEE Computer Society Press.
  TSP Suite, benchmarking, OR, logistics, more infos.
• Weichen LIU (刘伟臣), Thomas Weise (汤卫思), Yuezhong WU (吴越钟), and Qi QI (齐琪): Combining Two Local Searches with Crossover: An Efficient Hybrid Algorithm for the Traveling Salesman Problem. Genetic and Evolutionary Computation Conference (GECCO'2017), July 15-19, 2017, Berlin, Germany, New York, NY, USA: ACM Press, pages 298–305.
  TSP, TSP Suite, logistics, local search, OR, more infos.
• Abhishek Awasthi, Jörg Lässig, Thomas Weise (汤卫思), and Oliver Kramer: Tackling Common Due Window Problem with a Two-Layered Approach. 10th International Conference on Combinatorial Optimization and Applications (COCOA'2016), Hong Kong, China, December 16-18, 2016, Lecture Notes in Computer Science (LNCS), volume 10043, pages 772–781, Cham, Switzerland: Springer.
  scheduling, OR, more infos.
• Thomas Weise (汤卫思), Yuezhong WU (吴越钟), Raymond Chiong, Ke TANG (唐珂), and Jörg Lässig: Global versus Local Search: The Impact of Population Sizes on Evolutionary Algorithm Performance. Journal of Global Optimization (JOGO) 66(3):511-534. November 2016.
  TSP Suite, TSP, logistics, EAs, benchmarking, local search, OR, more infos.
• Yuezhong WU (吴越钟), Thomas Weise (汤卫思), and Weichen LIU (刘伟臣): Hybridizing Different Local Search Algorithms with Each Other and Evolutionary Computation: Better Performance on the Traveling Salesman Problem. 18th Genetic and Evolutionary Computation Conference (GECCO'2016), Denver, Colorado, USA, July 20-24, 2016, pages 57–58, New York, NY, USA: ACM.
  TSP Suite, TSP, logistics, local search, OR, more infos.
• Weichen LIU (刘伟臣), Thomas Weise (汤卫思), Yuezhong WU (吴越钟), Dan XU (许丹), and Raymond Chiong: An Improved Ejection Chain Method and Its Hybrid Versions for Solving the Traveling Salesman Problem. Journal of Computational and Theoretical Nanoscience 13(6):3601-3610. June 2016.
  TSP Suite, TSP, logistics, local search, OR, more infos.
• Abhishek Awasthi, Jörg Lässig, Jens Leuschner, and Thomas Weise (汤卫思): GPGPU-based Parallel Algorithms for Scheduling Against Due Date. 6th IEEE Workshop on Parallel Computing and Optimization (PCO'2016), part of the IEEE 30th  International Parallel and Distributed Processing Symposium (IPDPS'2016), May 23-27, 2016, Chicago, IL, USA, pages 766–775. Piscataway, NJ, USA: IEEE Computer Society.
  scheduling, OR, more infos.
• Wei SHI (施玮), Thomas Weise (汤卫思), Raymond Chiong, and Bülent Çatay: Hybrid PACO with Enhanced Pheromone Initialization for Solving the Vehicle Routing Problem with Time Windows. IEEE Symposium on Computational Intelligence in Production and Logistics Systems (CIPLS'2015), part of the IEEE Symposium Series on Computational Intelligence (SSCI'2015), December 8-10, 2015, Cape Town, South Africa, pages 1735–1742. Los Alamitos, CA, USA: IEEE Computer Society Press.
  VRP, ACO, logistics, OR, more infos.
• Chao GAO, Xin YAO (姚新), Thomas Weise (汤卫思), and Jinlong LI (李金龙): An Efficient Local Search Heuristic with Row Weighting for the Unicost Set Covering Problem. European Journal of Operational Research (EJOR) 246(3):750-761. November 2015.
  local search, OR, more infos.
• Dan XU (许丹), Thomas Weise (汤卫思), Yuezhong WU (吴越钟), Jörg Lässig, and Raymond Chiong: An Investigation of Hybrid Tabu Search for the Traveling Salesman Problem. 10th International Conference on Bio-Inspired Computing — Theories and Applications (BIC-TA'2015), September 25-28, 2015, Hefei, Anhui, China, Communications in Computer and Information Science, volume 562. Berlin/Heidelberg: Springer-Verlag, pages 523–537.
  TSP, TSP Suite, logistics, Tabu Search, local search, OR, more infos.
• Weichen LIU (刘伟臣), Thomas Weise (汤卫思), Yuezhong WU (吴越钟), and Raymond Chiong: Hybrid Ejection Chain Methods for the Traveling Salesman Problem. 10th International Conference on Bio-Inspired Computing — Theories and Applications (BIC-TA'2015), September 25-28, 2015, Hefei, Anhui, China, Communications in Computer and Information Science, volume 562. Berlin/Heidelberg: Springer-Verlag, pages 268–282.
  TSP, TSP Suite, logistics, local search, OR, more infos.
• Yuezhong WU (吴越钟), Thomas Weise (汤卫思), and Raymond Chiong: Local Search for the Traveling Salesman Problem: A Comparative Study. 14th IEEE Conference on Cognitive Informatics & Cognitive Computing (ICCI*CC'2015), July 6-8, 2015, Beijing, China, pages 213–220, Los Alamitos, CA, USA: IEEE Computer Society Press.
  TSP, TSP Suite, logistics, local search, benchmarking, OR, more infos.
• Yan JIANG (江炎), Thomas Weise (汤卫思), Jörg Lässig, Raymond Chiong, and Rukshan Athauda: Comparing a Hybrid Branch and Bound Algorithm with Evolutionary Computation Methods, Local Search and their Hybrids on the TSP. IEEE Symposium on Computational Intelligence in Production and Logistics Systems (CIPLS'2014), part of the IEEE Symposium Series on Computational Intelligence (SSCI'2014), December 9-12, 2014, Orlando, FL, USA, pages 148–155. Los Alamitos, CA, USA: IEEE Computer Society Press.
  TSP, TSP Suite, logistics, local search, B&B, EAs, MAs, OR, more infos.
• Abhishek Awasthi, Jörg Lässig, Oliver Kramer, and Thomas Weise (汤卫思): Common Due-Window Problem: Polynomial Algorithms for a Given Processing Sequence. IEEE Symposium on Computational Intelligence in Production and Logistics Systems (CIPLS'2014), part of the IEEE Symposium Series on Computational Intelligence (SSCI'2014), December 9-12, 2014, Orlando, FL, USA, pages 32–39. Los Alamitos, CA, USA: IEEE Computer Society Press.
  scheduling, OR, more infos.
• Chao GAO, Thomas Weise (汤卫思), and Jinlong LI (李金龙): Improve the 3-flip Neighborhood Local Search by Random Flat Move for the Set Covering Problem. Advances in Swarm Intelligence Proceedings of the 5th International Conference on Swarm Intelligence (ICSI'2014), Part 1, October 17-20, 2014, Hefei, Anhui, China, pages 27–35, Lecture Notes in Computer Science (LNCS), volume 8794. Berlin, Germany: Springer-Verlag GmbH.
  local search, OR, more infos.
• Thomas Weise (汤卫思), Raymond Chiong, Jörg Lässig, Ke TANG (唐珂), Shigeyoshi Tsutsui, Wenxiang CHEN (陈文祥), Zbigniew Michalewicz, and Xin YAO (姚新): Benchmarking Optimization Algorithms: An Open Source Framework for the Traveling Salesman Problem. IEEE Computational Intelligence Magazine (CIM) 9(3):40-52. August 2014.
  TSP, TSP Suite, logistics, local search, EAs, MAs, ACO, EDAs, FFA, OR, more infos.
• Chao GAO, Thomas Weise (汤卫思), and Jinlong LI (李金龙): A Weighting-Based Local Search Heuristic Algorithm for the Set Covering Problem. IEEE Congress on Evolutionary Computation (CEC'2014), part of the World Congress on Computational Intelligence (WCCI'2014), pages 826–831, July 6-11, 2014, Beijing, China. Los Alamitos, CA, USA: IEEE Computer Society Press.
  local search, OR, more infos.
• Kai ZHANG, Thomas Weise (汤卫思), and Jinlong LI (李金龙): Fitness Level based Adaptive Operator Selection for Cutting Stock Problems with Contiguity. IEEE Congress on Evolutionary Computation (CEC'2014), part of the World Congress on Computational Intelligence (WCCI'2014), pages 2539–2546, July 6-11, 2014, Beijing, China. Los Alamitos, CA, USA: IEEE Computer Society Press.
  EAs, packing, OR, more infos.
• Wei SHI (施玮) and Thomas Weise (汤卫思): An Initialized ACO for the VRPTW. 14th International Conference on Intelligent Data Engineering and Automated Learning (IDEAL'2013), October 20-23, 2013, Hefei, Anhui, China, Lecture Notes in Computer Science (LNCS), volume 8206/2013, pages 93–100. Berlin, Germany: Springer-Verlag GmbH.
  ACO, VRP, logistics, OR, metaheuristics, more infos.
• Jin OUYANG (欧阳晋), Thomas Weise (汤卫思), Alexandre Devert, and Raymond Chiong: SDGP: A Developmental Approach for Traveling Salesman Problems. IEEE Symposium on Computational Intelligence in Production and Logistics Systems (CIPLS'2013), part of the IEEE Symposium Series on Computational Intelligence (SSCI'2013), April 15-19, 2013, Singapore, pages 78–85, Los Alamitos, CA, USA: IEEE Computer Society Press.
  TSP, logistics, GP, OR, more infos.
• Thomas Weise (汤卫思), Alexandre Devert, and Ke TANG (唐珂): A Developmental Solution to (Dynamic) Capacitated Arc Routing Problems using Genetic Programming. 14th Genetic and Evolutionary Computation Conference (GECCO'2012), July 7-11, 2012, Philadelphia, PA, USA, pages 831–838. New York, NY, USA: ACM.
  CARP, logistics, GP, OR, metaheuristics, more infos.
• Thomas Weise (汤卫思) and Raymond Chiong: A Novel Extremal Optimization Approach for the Template Design Problem. International Journal of Organizational and Collective Intelligence (IJOCI) 2(2):1-17. April-June 2011.
  local search, packing, OR, more infos.
• Raymond Chiong, Thomas Weise (汤卫思), and Bee Theng Lau: Template Design using Extremal Optimization with Multiple Search Operators. International Conference on Soft Computing and Pattern Recognition (SoCPaR'2009), December 4-7, 2009, Malacca, Malaysia, pages 202–207. Piscataway, NJ, USA: IEEE.
  packing, local search, OR, metaheuristics, more infos.
• Thomas Weise (汤卫思), Alexander Podlich, and Christian Gorldt: Solving Real-World Vehicle Routing Problems with Evolutionary Algorithms. Natural Intelligence for Scheduling, Planning and Packing Problems, chapter 2, pages 29–53, Studies in Computational Intelligence, volume 250. Berlin/Heidelberg: Springer-Verlag, October 2009.
  VRP, logistics, EAs, OR, metaheuristics, more infos.
• Thomas Weise (汤卫思) and Raymond Chiong: . Intelligent Systems for Automated Learning and Adaptation: Emerging Trends and Applications, chapter 6, pages 114–149. Hershey, PA, USA: Information Science Reference / IGI Global, September 2009.
  EAs, distributed systems, metaheuristics, OR, more infos.
• Thomas Weise (汤卫思), Alexander Podlich, Manfred Menze, and Christian Gorldt: Optimierte Güterverkehrsplanung mit Evolutionären Algorithmen. Industrie Management — Zeitschrift für industrielle Geschäftsprozesse 10(3):37–40. June 2009.
  EAs, VRP, logistics, OR, metaheuristics, more infos.
• Thomas Weise (汤卫思), Alexander Podlich, Kai Reinhard, Christian Gorldt, and Kurt Geihs: Evolutionary Freight Transportation Planning. Applications of Evolutionary Computing — Proceedings of EvoWorkshops'2009, April 15-17, 2009, Tübingen, Germany: Eberhard-Karls-Universität Tübingen, Lecture Notes in Computer Science (LNCS), volume 5484/2009, pages 768–777. Berlin, Germany: Springer-Verlag GmbH.
  EAs, VRP, logistics, OR, metaheuristics, more infos.
• Alexander Podlich, Thomas Weise (汤卫思), Manfred Menze, and Christian Gorldt: Intelligente Wechselbrückensteuerung für die Logistik von Morgen. Workshops der Wissenschaftlichen Konferenz Kommunikation in Verteilten Systemen (WowKiVS'2009), March 6, 2009, Kassel, Hesse, Germany. In Electronic Communications of the EASST (ECEASST), volume 17, Potsdam, Germany: European Association of Software Science and Technology.
  EAs, VRP, logistics, OR, metaheuristics, more infos.