constraint programming provides a powerful framework for modeling and solving combinatorial problems. However, manually defining the required constraints can be a challenging task that requires a high level of experti...
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ISBN:
(纸本)9798400709821
constraint programming provides a powerful framework for modeling and solving combinatorial problems. However, manually defining the required constraints can be a challenging task that requires a high level of expertise. constraint acquisition (CA) techniques aim to semi-automate this process by learning constraints from examples of solutions and non-solutions. One important factor that can impact the effectiveness of CA is the diversity of the example solutions provided. This paper investigates how solution diversity influences passive learning approaches for CA across three distinct problems and various diversity metrics. Our results demonstrate that solution diversity significantly influences the quality of learned constraints, highlighting the importance of diverse solution sets. In addition, we show how we can predict whether a given set of solutions will enable accurate constraint learning using a machine learning (ML) model. Our experimental evaluation shows that the ML model can accurately predict the recall of the CA system based on the solution set's diversity metrics and the number of solutions.
This paper addresses the integrated flexible job shop and operators scheduling problem, introducing shift-based constraints on operators. We investigate how the advanced modeling and solution techniques, specifically,...
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This paper addresses the integrated flexible job shop and operators scheduling problem, introducing shift-based constraints on operators. We investigate how the advanced modeling and solution techniques, specifically, Mixed-Integer programming (MIP) and constraint programming (CP) perform on this intricate scheduling problem. We test the effectiveness of both the MIP and CP models on an illustrative example as well as on a set of larger instances and draw conclusions, which indicate the need to integrate these two models into some approximation scheme to tackle large-scale instances for this complex problem. Copyright (C) 2024 The Authors. This is an open access article under the CC BY-NC-ND license (https://***/licenses/by-nc-nd/4.0/)
An important criteria to assert the security of a cryptographic primitive is its resistance against differential cryptanalysis. For word-oriented primitives, a common technique to determine the number of rounds requir...
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ISBN:
(纸本)9783031562310;9783031562327
An important criteria to assert the security of a cryptographic primitive is its resistance against differential cryptanalysis. For word-oriented primitives, a common technique to determine the number of rounds required to ensure the immunity against differential distinguishers is to consider truncated differential characteristics and to count the number of active S-boxes. Doing so allows one to provide an upper bound on the probability of the best differential characteristic with a reduced computational cost. However, in order to design very efficient primitives, it might be needed to evaluate the probability more accurately. This is usually done in a second step, during which one tries to instantiate truncated differential characteristics with actual values and computes its corresponding probability. This step is usually done either with ad-hoc algorithms or with CP, SAT or MILP models that are solved by generic solvers. In this paper, we present a generic tool for automatically generating these models to handle all word-oriented ciphers. Furthermore the running times to solve these models are very competitive with all the previous dedicated approaches.
Railcars arriving at the railroad technical station include transfer and local railcars. Local railcars are loaded, unloaded, and inspected through pick-up and delivery operations before being marshalled into departur...
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ISBN:
(纸本)9798350358513;9798350358520
Railcars arriving at the railroad technical station include transfer and local railcars. Local railcars are loaded, unloaded, and inspected through pick-up and delivery operations before being marshalled into departure trains. The technical station wagon-flow allocation problem, as the core issue of its transportation scheduling, is essentially the process of selecting and matching various wagon-flow, which has a profound impact on the overall transportation capacity of the station. Therefore, this article first establishes a constraint programming model to focus on the coordinated optimization problem of wagon-flow allocation and pick-up and delivery operations at the railway technical station. constraints such as operational sequencing, wagon-flow continuity, locomotive usage, and full axle capacity are considered. The primary objective is to maximize the total priority of successfully assembled departure trains. The other objectives include maximizing shunting and track utilization rates and minimizing the number of sources of successful assembled wagon-flow. Additionally, a fast iterative solution algorithm with initial solutions is designed based on constraint propagation and constructive search strategy, achieving hierarchical iterative solution of the entire model. Finally, using actual data from a specific district station as a case study, the verification results show that the method proposed can solve the coordination among pick-up, delivery, disassembly and assembly operations. It can achieve comprehensive utilization of wagon-flow and coordinated wagon-flow allocation of departure trains based on decision-making on pick-up and delivery order, and the algorithm's solving efficiency meets the requirements of on-site timeliness.
The evolution of production scheduling in the context of Industry 4.0 and green manufacturing has become a focal point in contemporary industrial research. Efficient scheduling, essential for optimal resource utilizat...
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ISBN:
(纸本)9783031686337;9783031686344
The evolution of production scheduling in the context of Industry 4.0 and green manufacturing has become a focal point in contemporary industrial research. Efficient scheduling, essential for optimal resource utilization and cost-effectiveness, faces new challenges due to the digital revolution and the green industry paradigm. This study conducts a comprehensive analysis of existing literature on scheduling problems, incorporating the dual perspectives of Industry 4.0 and green production. The research delves into diverse problem formulations and solution approaches, ranging from mathematical programming techniques to heuristic methods and machine learning concepts. The review reveals a scarcity of studies addressing the complexities arising from the integration of Industry 4.0 technologies and ecological considerations in production scheduling. Bridging this gap is crucial, urging further research at the intersection of Industry 4.0 and sustainable manufacturing practices. The study emphasizes the significance of addressing these challenges, considering the complexities of real-world scheduling scenarios, where practical problems involve operations ranging from thousands to hundreds of thousands. By exploring advanced solutions, encompassing machine learning, constraint programming, and metaheuristic methods, the research underscores the need for continued exploration and development of robust strategies applicable to large-scale, practical settings. This interdisciplinary approach is pivotal in shaping the future of industrial scheduling, ensuring efficiency, sustainability, and resilience in the face of evolving technological landscapes and environmental imperatives.
This paper presents a deterministic parallelization to explore a constraint programming search space. This work is an answer to an industrial project named PAJERO, which is in need of a parallel constraint solver whic...
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ISBN:
(纸本)9781632662163
This paper presents a deterministic parallelization to explore a constraint programming search space. This work is an answer to an industrial project named PAJERO, which is in need of a parallel constraint solver which always responds with the same solution whether using sequential or parallel machines. It is well known that parallel tree search changes the order in which the exploration of solution space is done. In the context where the first solution found is returned, using a different number of cores may change the returned solution. In the literature, several non deterministic strategies have been proposed to parallelize the exploration of constraint programming search space. Most of them are based on the Work Stealing technique used to partition the constraint programming search space on demand and during the execution of the search algorithm. Our study focuses on the determinism of the parallel search versus the sequential one. We consider that the sequential search algorithm is deterministic, then propose an elegant and simple solution introducing a total order on the nodes in which the parallel algorithm always gives the same solution as the sequential one regardless of the number of cores used. To evaluate this deterministic strategy, we ran tests using the Google OR-Tools constraint programming solver on top of our parallel Bobpp framework. The performances are illustrated by solving constraint programming problems modeled in FlatZinc format.
Fog Computing extends Cloud Computing to the network edge, enhancing distributed computing to meet the growing needs of Internet of Things (IoT) applications requiring real-time or near-real-time analysis. This resear...
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ISBN:
(纸本)9783031695766;9783031695773
Fog Computing extends Cloud Computing to the network edge, enhancing distributed computing to meet the growing needs of Internet of Things (IoT) applications requiring real-time or near-real-time analysis. This research focuses on efficiently managing the vast amounts of data generated by IoT devices and the continuous data streams they produce, employing an advanced replication and placement strategy for application components across distributed Fog Computing nodes. This approach enables scalable and parallel data processing to adapt to demand fluctuations, prevent over-provisioning, and maintain low response times, making it particularly effective for the dynamic nature of data stream processing in IoT applications. In this paper, we propose an Optimal IoT Service Replication and Placement (SRP) model, formulated as a constraint satisfaction problem, that considers the diverse requirements of IoT applications and the available infrastructure resources. Our model is designed to be adaptive and extensible, addressing the challenge of workload variability through real-time optimization. Numerical evaluations confirm the superior performance and scalability of our model over existing methods, while maintaining quality of service constraints. This highlights the potential of our approach to improve efficiency and resource management in Fog Computing environments.
This study addresses the integration of the railway and airline scheduling problems, in order to offer passengers smooth transfers between rail and air. This paper focuses on optimising the air and rail timetables at ...
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This study addresses the integration of the railway and airline scheduling problems, in order to offer passengers smooth transfers between rail and air. This paper focuses on optimising the air and rail timetables at 18 major European airports including three hubs and their associated train stations. A multimodal passenger demand simulation, using constraint programming and based on real data, is proposed. A typical week, from Monday to Saturday, of December 2019 is analysed. Ten passenger demand simulations are run for each day, resulting in 60 test instances that are publicly released. The air-rail timetable synchronisation is applied to these 60 instances. Three scenarios are tested in which each operator agrees to change its schedule or not. Results show that changing the schedule of only 13% of European flights by 11 min, and half of trains scheduled to stop at the three hubs of 17 min, on average, could increase the number of suitable connections for passengers by 60%. In addition, if both airlines and railway operators adapt their schedules, passenger comfort is improved and operator costs are reduced, even more so than with unilateral changes.
Effective resource planning presents a broad problem across industries due to inner operational constraints. Existing methods are hard for generalization because they entail either unique models or customized specific...
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ISBN:
(纸本)9798350354102;9798350354096
Effective resource planning presents a broad problem across industries due to inner operational constraints. Existing methods are hard for generalization because they entail either unique models or customized specific solutions. To address this challenge, we pose the Operationally-Constrained Resource Planning Problem (OCRPP), which abstract assets and resources using job concepts to decouple the entangled constraints to describe the resource planning problem in a standard way. Meanwhile, we propose the Hierarchical Allocation Optimizer (HAO), a meta-heuristic solving framework containing 3 phases, to speed up feasible solution search with lower bound estimation. Experiments show HAO's superiority in terms of time and objectives compare to the alternatives, which adopts rule-based heuristic or general meta-heuristic. HAO's rapid response and flexibility are demonstrated to show its capability to adapt to various business scenarios and applications such as airlines, logistics companies, and so on.
We address two variants of the two-dimensional guillotine cutting problem that appear in different manufacturing settings that cut defective objects. Real-world applications include the production of flat glass in the...
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We address two variants of the two-dimensional guillotine cutting problem that appear in different manufacturing settings that cut defective objects. Real-world applications include the production of flat glass in the glass industry and the cutting of wooden boards with knotholes in the furniture industry. These variants assume that there are several defects in the object, but the items cut should be defective-free;the cutting pattern is limited to two guillotine stages;and the maximum number of copies per item type in the pattern can be limited. The first variant deals with exact 2-stage patterns, while the second with exact 1-group patterns. To effectively solve these problems, we propose a constraint programming (CP) based algorithm as well as different Integer Linear programming (ILP) formulations. The first presented formulations are extensions of the modelling approach of [Martin, M., E. G. Birgin, R. D. Lobato, R. Morabito, and P. Munari. 2020. "Models for the Two-Dimensional Rectangular Single Large Placement Problem with Guillotine Cuts and Constrained Pattern." International Transactions in Operational Research 27: 767-793. doi:] for the case with defects, while the others are novel and more elaborate formulations based on the relative position of the items. We evaluate these three approaches with computational experiments using a set of benchmark instances from the literature. The results show that the approaches find optimal and near-optimal solutions in short processing times for several types of problem instances.
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