scholarly journals Multimodal Processes Rescheduling: Cyclic Steady States Space Approach

2013 ◽  
Vol 2013 ◽  
pp. 1-24 ◽  
Author(s):  
Grzegorz Bocewicz ◽  
Robert Wójcik ◽  
Zbigniew Antoni Banaszak ◽  
Paweł Pawlewski
Keyword(s):  
Constraint Satisfaction ◽  
Material Handling ◽  
Constraint Satisfaction Problem ◽  
Transportation Network ◽  
Cyclic Scheduling ◽  
Scheduling Problems ◽  
Multimodal Transportation ◽  
Shared Workstations ◽  
Production Orders ◽  
Space Approach

The paper concerns cyclic scheduling problems arising in a Multimodal Transportation Network (MTN) in which several unimodal networks (AGVs, hoists, lifts, etc.) interact with each other via common shared workstations as to provide a variety of demand-responsive material handling operations. The material handling transport modes provide movement of work-pieces between workstations along their manufacturing routes in the MTN. The goal is to provide a declarative framework enabling to state a constraint satisfaction problem aimed at AGVs fleet match-up scheduling taking into consideration assumed itineraries of concurrently manufactured product types. In that context, treating the different product types as a set of cyclic multimodal processes is the main objective to discuss the conditions sufficient for FMS rescheduling imposed by production orders changes. To conclude, the conditions sufficient for an FMS rescheduling imposed by changes of production orders treated as cyclic multimodal processes are stated as the paper’s main contribution.

Multi-Layer Distributed Constraint Satisfaction for Multi-criteria Optimization Problem

2020 ◽  
Vol 11 (2) ◽  
pp. 134-155 ◽  
Author(s):  
Mouna Gargouri Mnif ◽  
Sadok Bouamama
Keyword(s):  
Constraint Satisfaction ◽  
Optimization Problem ◽  
Transportation Network ◽  
Optimization Methods ◽  
Planning Problem ◽  
Scheduling Problems ◽  
Present Contribution ◽  
Multimodal Transportation ◽  
New Approach ◽  
Distributed Constraint Satisfaction

This article introduces a new approach to solve the multimodal transportation network planning problem (MTNP). In this problem, the commodities must be transported from an international network by at least two different transport modes. The main purpose is to identify the best multimodal transportation strategy. The present contribution focuses on efficient optimization methods to solve MTNP. This includes the assignment and the scheduling problems. The authors split the MTNP into layered. Each layer is presented by an agent. These agents interact, collaborate, and communicate together to solve the problem. This article defines MTNP as a distributed constraint satisfaction multi-criteria optimization problem (DCSMOP). This latter is a description of the constraint optimization problem (COP), where variables and constraints are distributed among a set of agents. Each agent can interact with other agents to share constraints and to distribute complementary tasks. Experimental results are the proof of this work efficiently.

Mass Customized Projects Portfolio Scheduling - Imprecise Operations Time Approach

2015 ◽  
Vol 791 ◽  
pp. 70-80 ◽  
Author(s):  
Krzysztof Bzdyra ◽  
Grzegorz Bocewicz ◽  
Zbigniew Banaszak
Keyword(s):  
Constraint Satisfaction ◽  
Production Scheduling ◽  
Manufacturing System ◽  
Constraint Satisfaction Problem ◽  
Medium Size ◽  
Shared Resources ◽  
Project Environment ◽  
Time Period ◽  
Production Order ◽  
Production Orders

Declarative framework enabling to determine conditions employed in a decision support systems aimed at small and medium size enterprises involved in a unique, multi project-like and mass customized oriented production is discussed. The unique production orders grouped into the set of portfolio orders is considered. To each production order treated as an activity network of common shared resources, known in advance, however by nature imprecise operation times are allotted. The problem concerns of scheduling of a newly inserted projects portfolio taking into account imprecise operations imposed by a multi–project environment. The answer sought is: Whether a given portfolio can be completed within assumed time period in a manufacturing system in hand? The goal is to provide a declarative model enabling to state a constraint satisfaction problem aimed at multi project-like and mass customized oriented production scheduling. The attached calculation example illustrates the computational efficiency of the proposed solution.

scholarly journals Multimodal processes scheduling in mesh-like network environment

2015 ◽  
Vol 25 (2) ◽  
pp. 237-261 ◽  
Author(s):  
Grzegorz Bocewicz ◽  
Zbigniew Banaszak
Keyword(s):  
Constraint Satisfaction Problem ◽  
Transportation Network ◽  
Transportation Systems ◽  
Telecommunication Networks ◽  
Planning And Scheduling ◽  
Multimodal Transportation ◽  
Transportation Services ◽  
Cyclic Processes ◽  
Multimodal Process ◽  
The Right

Abstract Multimodal processes planning and scheduling play a pivotal role in many different domains including city networks, multimodal transportation systems, computer and telecommunication networks and so on. Multimodal process can be seen as a process partially processed by locally executed cyclic processes. In that context the concept of a Mesh-like Multimodal Transportation Network (MMTN) in which several isomorphic subnetworks interact each other via distinguished subsets of common shared intermodal transport interchange facilities (such as a railway station, bus station or bus/tram stop) as to provide a variety of demand-responsive passenger transportation services is examined. Consider a mesh-like layout of a passengers transport network equipped with different lines including buses, trams, metro, trains etc. where passenger flows are treated as multimodal processes. The goal is to provide a declarative model enabling to state a constraint satisfaction problem aimed at multimodal transportation processes scheduling encompassing passenger flow itineraries. Then, the main objective is to provide conditions guaranteeing solvability of particular transport lines scheduling, i.e. guaranteeing the right match-up of local cyclic acting bus, tram, metro and train schedules to a given passengers flow itineraries.

Declarative Approach to AGVS Modeling and Cyclic Scheduling

2013 ◽  
Vol 421 ◽  
pp. 573-578
Author(s):  
Grzegorz Bocewicz ◽  
Muszyński Wojciech ◽  
Zbigniew Banaszak
Keyword(s):  
Flexible Manufacturing ◽  
Material Handling ◽  
Constraint Satisfaction Problem ◽  
Schedulability Analysis ◽  
Cyclic Scheduling ◽  
Concurrent Process ◽  
Process Systems ◽  
Declarative Modeling ◽  
The Common ◽  
Transportation Route

The paper presents constraint satisfaction problem driven approach to analytical solution of the cyclic scheduling problem in the Flexible Manufacturing System (FMS) producing multi-type parts where for material handling are used the Automated Guide Vehicles Systems (AGVS). Finding the conditions guaranteeing the AGVs deadlock-free and collision-free movement policy is the aim of our researches. The AGVs co-sharing the common parts of the transportation route while executing repetitive processes, i.e. being assigned to AGVs passing along machines in a cyclic way, can be modeled in terms of Cyclic Concurrent Process Systems (CCPS). Schedulability analysis for a given CCPS answers the question whether a cyclic schedule exists or not. The paper suggests approach for schedulability analysis of multimodal processes representing real manufacturing employing the declarative modeling.

scholarly journals Permutation groups with small orbit growth

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Manuel Bodirsky ◽  
Bertalan Bodor
Keyword(s):  
Automorphism Group ◽  
Constraint Satisfaction ◽  
Constraint Satisfaction Problem ◽  
Permutation Groups ◽  
First Order ◽  
Finite Covers

Abstract Let K exp + \mathcal{K}_{{\operatorname{exp}}{+}} be the class of all structures 𝔄 such that the automorphism group of 𝔄 has at most c ⁢ n d ⁢ n cn^{dn} orbits in its componentwise action on the set of 𝑛-tuples with pairwise distinct entries, for some constants c , d c,d with d < 1 d<1 . We show that K exp + \mathcal{K}_{{\operatorname{exp}}{+}} is precisely the class of finite covers of first-order reducts of unary structures, and also that K exp + \mathcal{K}_{{\operatorname{exp}}{+}} is precisely the class of first-order reducts of finite covers of unary structures. It follows that the class of first-order reducts of finite covers of unary structures is closed under taking model companions and model-complete cores, which is an important property when studying the constraint satisfaction problem for structures from K exp + \mathcal{K}_{{\operatorname{exp}}{+}} . We also show that Thomas’ conjecture holds for K exp + \mathcal{K}_{{\operatorname{exp}}{+}} : all structures in K exp + \mathcal{K}_{{\operatorname{exp}}{+}} have finitely many first-order reducts up to first-order interdefinability.

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