VLDB 2026 Research / reviewers in the wild / expert
Slim Hammadi
dblp:08/7019
· DBLP profile ↗
46ranked-venue papers
1as first author
8since 2021 · last 2025
0000-0002-5187-4870ORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Applied, interdisciplinary, general and emerging computing · 31 · 6 since 2021Human-computer interaction and ubiquitous computing · 29 · 1 first-author · 4 since 2021Artificial intelligence and machine learning · 7 · 2 since 2021Software engineering, systems software and programming languages · 2 · 1 since 2021Systems, architecture and hardware · 1
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | Enhancing particulate matter risk assessment with novel machine learning-driven toxicity threshold predictionabstractAirborne particulate matter (PM) poses significant health risks, necessitating accurate toxicity threshold determination for effective risk assessment. This study introduces a novel machine-learning (ML) approach to predict PM toxicity thresholds and identify the key physico-chemical and exposure characteristics. Five machine learning algorithms — logistic regression, support vector classifier , decision tree, random forest, and extreme gradient boosting — were employed to develop predictive models using a comprehensive dataset from existing studies. We developed models using the initial dataset and a class weight approach to address data imbalance. For the imbalanced data, the Random Forest classifier outperformed others with 87% accuracy, 81% recall, and the fewest false negatives (23). In the class weight approach, the Support Vector Classifier minimized false negatives (21), while the Random Forest model achieved superior overall performance with 86% accuracy, 80% recall, and an F1-score of 82%. Furthermore, eXplainable Artificial Intelligence (XAI) techniques, specifically SHAP (SHapley Additive exPlanations) values, were utilized to quantify feature contributions to predictions, offering insights beyond traditional laboratory approaches. This study represents the first application of machine learning for predicting PM toxicity thresholds, providing a robust tool for health risk assessment. The proposed methodology offers a time- and cost-effective alternative to classical laboratory tests, potentially revolutionizing PM toxicity threshold determination in scientific and epidemiological research. This innovative approach has significant implications for shaping regulatory policies and designing targeted interventions to mitigate health risks associated with airborne PM. Idriss Jairi, Amelle Rekbi, Sarah Ben Othman, Slim Hammadi, Ludivine Canivet, Hayfa Zgaya |
Eng. Appl. Artif. Intell. | 4 |
| 2025 | A Matheuristic Approach for Delivery Planning and Dynamic Vehicle Routing in Logistics 4.0abstractIn distribution logistics, the planning of vehicles’ routes and vehicles’ loads are traditionally managed separately, despite these activities are correlated. This often leads to various re-designs to make the routes and load plans compatible and applicable in practice. Moreover, the planned routes, which are static by definition, cannot always cope with unexpected events. Traffic congestion, vehicle failures, adverse meteorological conditions, and further undesired events can make the planned routes inapplicable and requirevehicles’ re-routing. This results in lower service levels, undesired delays, and higher costs for logistics companies. With the aim of overcoming the above limitations, this work proposes a novel approach based on a matheuristic algorithm that jointly solves the problem ofdelivery planninganddynamic vehicle routingto automate the delivery process in a logistics 4.0 perspective. The presented algorithm includes two different phases: the static phase, which is executed offline and in advance with respect to the delivery day, and the dynamic phase, which is executed in real-time to cope with unexpected events during the delivery. For the first phase, a matheuristic approach is defined to efficiently solve the combined vehicle routing and loading problems. Differently, for the second phase, a genetic algorithm is proposed to re-route vehicles in real-time, considering both the redefinition in real-time of the nominal trip and/or of the sequence of the customers to be visited. The algorithm is tested both on a literature benchmark and on a real dataset provided by an Italian logistics company. The obtained results show that, on the one hand, the proposed algorithm can automatically provide feasible solutions that minimise travel costs, total travelled distance, and empty space on the vehicles; on the other hand, it can ensure in real-time effective re-routing solutions in case of unexpected events occurring during delivery.Note to Practitioners—This work is motivated by the need for facilitating the operations of planning and routing deliveries in the external logistics sector. We propose an algorithm that automatically generates feasible routing and loading plans for a set of Transport Units (TUs) (i.e., the static phase), and then updates in real-time the nominal route in case of unexpected events (i.e., the dynamic phase). More specifically, the first phase of the algorithm takes as input the set of different clients, the list of products packed into bins (i.e., standard packing units) to be delivered to each client, and the set of transport units available for the deliveries, and provides as output the number and type of TUs to be used, the composition of the bins in each transport unit, and the corresponding route, while optimising the space occupation in each TU and the travel costs. The second phase, instead, takes as input the nominal routes computed in the first phase and, in case of unexpected events (e.g., accidents, slowdowns, etc.) affecting one or more routes, it re-routes the involved trucks guaranteeing the maximum efficiency in regards to travel cost, travel time, and quality of service. The adoption of this algorithm by logistic companies supports the automation of the delivery process and drastically improves the efficiency of logistic operations, with particular regard to the number of used TUs, costs, safety of goods, and customers’ satisfaction. Giulia Tresca, Hadrien Salem, Graziana Cavone, Hayfa Zgaya, Sarah Ben Othman, Slim Hammadi, Mariagrazia Dotoli |
IEEE Trans Autom. Sci. Eng. | 6 |
| 2024 | AI-Driven Strategies for Precision and Efficiency in Optimising Medical Iatrogeny DetectionabstractMedication iatrogeny is a significant patient safety challenge in the healthcare field. This issue pertains to the undesirable effects resulting from the use of drugs, including errors in prescribing, dosing, or administration. In this context, the use of Machine Learning (ML) techniques to predict clinical outcomes is becoming increasingly common. The objective of this work is to develop a decision-support system designed to provide recommendations and assist pharmacists in analyzing prescriptions to reduce the risks associated with iatrogenic medication use for patients. ML algorithms are applied to classify prescriptions as valid or invalid using a MIMIC database containing patient medical data. We followed strict guidelines to process the data to improve model performance and then evaluated the model's performance using cross-validation, referring to standard metrics. The system integrates with existing hospital software, allowing pharmacists to receive recommendations and alerts for potential medication errors. We obtained an average accuracy of 96% for predicting the validity of medical prescriptions. Our study demonstrates that the use of ML algorithms for predicting the validity of medical prescriptions is an effective method. The results also suggest that diversifying the data could improve the model's performance. The findings of this study have valuable implications for clinical practice by providing a useful tool for the early detection of medication errors and could contribute to the enhancement of decision support systems in medicine. Sarah Ben Othman, Faiza Ajmi, Bertrand Decaudin, Pascal Odou, Chloé Rousselière, Etienne Cousein, Slim Hammadi |
CoDIT | 7 |
| 2022 | Agent-based Modeling for Dynamic Hitchhiking Simulation and OptimizationabstractInternational audience Corwin Fèvre, Hayfa Zgaya, Philippe Mathieu, Slim Hammadi |
ICAART (1) | 4 |
| 2022 | An Agent-Based Metaheuristic with Cooperation Approach applied for patients'scheduling in hospital emergency departmentabstractIn this paper, we propose an innovative meta-heuristic characterized by a multi-dimensional chromosome where each dimension is driven by a rational agent. These agents have to communicate in order to implement evolving and adaptive genetic operators to accelerate the convergence towards the optimal solution. This cooperative approach is applied to solve the patient scheduling problem in emergency department (ED). This problem is NP-difficult due to the permanent interference between three types of arrival: already programmed patients, non-programmed patients and urgent non-programmed patients. Our scheduling problem has to integrate several dimensions such as medical dimensional, patient dimensional, temporal dimensional. The multi-dimensional aspect of the chromosome is crucial to model the different dimensions of the ED. The main goal of the simulation results is to assess the performance of the proposed agent driven multidimensional chromosome. The simulation results confirm that the intra and inter chromosomal interactions allow to avoid the blind aspect of the genetic operators and impacts the quality of solutions. The agents’ cooperation and its ability to improve efficiently the quality of the solutions by exploring intelligently the research space are confirmed by the drop in average total patient waiting time by 15.09% Faiza Ajmi, Faten Ajmi, Sarah Ben Othman, Hayfa Zgaya, Jean-Marie Renard, Grégoire Smith, Slim Hammadi |
SMC | 7 |
| 2022 | Dynamic Dempster Multi-Layer Perceptron for the prediction of admission patient in emergency departmentabstractThe early identification of the patients’ hospitalization at triage level within the Emergency Department (ED) presents a potential solution to reduce the risk of overcrowding and improve the quality of care. Thus, predicting patient out-come on arrival assists medical staff in the make of the appropriate patient pathway decision and so reduces the risk of medical error and complication of the patient’s condition. Previous works don’t consider the uncertainty of medical data while the management of this uncertainty is one of the most important and crucial tasks of medical information systems. Thus, we present in this paper an improved version of the classical prediction model by taking into account the uncertainty and by managing properly the missing information. In this context, we propose a new approach based on Dempster-Shafer theory and Dynamic Multi-Layer Perceptron algorithm. Our proposed approach deploys the correspondent neural network as follows: 1) computes for each input parameter the Basic Belief Assignment (BBA) that provides an assessment of the uncertainty pattern using the Dempster’s rule; 2) deduces the correspondent weights based on the computed BBA, and 3) uses an appropriate transfer function to activate the next layer neurons. In this paper, we demonstrate the effectiveness of our proposed method by using a real ED database. We prove that our proposed approach manages efficiently the uncertainty of the medical data sources and missing information, so improves the decision making and reduces errors and complexity. Khouloud Fakhfakh, Sarah Ben Othman, Hayfa Zgaya, Laetitia Vermeulen-Jourdan, Jean-Marie Renard, Slim Hammadi |
SMC | 6 |
| 2021 | Friends and enemies agents collaboration protocol to optimize multi-skills patient scheduling in emergency departmentabstractThis paper focuses on scheduling patients in emergency department (ED) according to the priority of patients’ treatments, determined by the triage process. This multi-skills patient scheduling problem is modeled through four dimensional (hypercube) solutions search space whose axes are: Medical staff, Patients, ED structure and Time and it can be formulated as a flexible job shop scheduling problem. We have then to solve a NP-hard combinatorial optimization problem (COP) in the emergency department (ED). The objective is to minimize a score integrating the total waiting time of patients in the (ED) with emphasis on patients with severe conditions. The Friends and Enemies collaboration protocol between agents is developed for solving the problem where each agent integrate a complete metaheuristic scheme in its behavior. Each agent act autonomously in the solution environment and interacts cooperatively with it and with the other agents. The interaction between agents allows the metaheuristic hybridization including the tuning of its parameters. The simulation results show that the scenarios with 2 or more agents were significantly higher in performance than the scenarios with 1 single agent. Thus, it is confirmed that the collaboration protocol between agents influences the quality of the solutions and the scalability of our approach, with the addition of new agents, there is an improvement in the results. Our approach is tested on a set of real (ED) data and the simulation results show that the proposed friends end enemies collaboration protocol can significantly improve the efficiency of the (ED) by reducing the score and especially the total waiting time of multi-skills patient scheduling problem. Faiza Ajmi, Faten Ajmi, Sarah Ben Othman, Hayfa Zgaya, Jean-Marie Renard, Grégoire Smith, Slim Hammadi |
SMC | 7 |
| 2021 | Multi-agent Systems and R-Trees for Dynamic and Optimised RidesharingabstractIn this paper, we study the multi-hop on-demand ridesharing between riders and drivers which are represented as autonomous and rational agents. The goal is to reach the best balance between ridesharing supply and demand. In this context, each agent has its own dynamic perception represented by a bounding box and computed according to its respective constraints and preferences. These perceptions are stored in a spatial R-Tree index allowing users to perform perception overlap queries and identify possible trip shares. The evaluation and selection of optimal path shares is performed by the rider agent based on its objective function. We perform experiments by varying the detour factor of the drivers and demonstrate the validity of our model. We point out the need for optimization on the selection of the optimal transfer node. Finally, we prove the efficiency of our multi-agent based multi-hop ridesharing in terms of service rate and saved distance. Corwin Fèvre, Hayfa Zgaya, Philippe Mathieu, Slim Hammadi |
SMC | 4 |
| 2020 | Generic agent-based optimization framework to solve combinatorial problemsabstractThe aim of this paper is to describe our proposed ABOS framework (Agent-Based Optimization Systems) by demonstrating the interest in using the multi-agent approach while operating hybrid metaheuristics to solve Combinatorial Optimization Problems (COP). Two main contributions are highlighted in this work: 1) to show that the alliance of the multi-agent systems (MAS) and the metaheuristics, based on the interaction and the parallelisms concepts, facilitates the hybrid metaheuristics development and allows the simultaneous exploration of different regions of the search space and 2) to demonstrate that the use the multi-agent approach, in the context of optimization, is a crucial option in the process of hybridization allowing the development of generic structures. These later promote the interaction between metaheuristics independent of the problem to be addressed. Our challenge in this ABOS framework is to endow the participant agents, with a set of rational behaviours allowing them to change in real time their strategies, according to the optimization process evolution. The simulation results show that the collaborative optimization can be effective in some cases, hence the need to set effectively the parameters of the optimization algorithms behaviours and the collaborative protocols. We also demonstrate that the use of ABOS framework with MAS allows a more robust and generic structure, capable with minimal changes handling different COP. Faiza Ajmi, Hayfa Zgaya, Sarah Ben Othman, Slim Hammadi |
SMC | 4 |
| 2020 | An improved evidence theory-based trust model for multiagent resource allocationabstractIn a resource allocation system, resource suppliers and customers can be naturally modelled as autonomous and interactive entities. In this context, we propose in this paper a multiagent system architecture based on trust and honesty concepts between agents in order to synchronize resource allocation in a distributed environment. Indeed, agents use several means in order to allocate resources efficiently as dialogue, adaptability, cooperation, collaboration and even negotiation in addition to the notion of trust. So, individual agents have to evaluate the trustworthiness of others to select those to interact with. Moreover, resource inadequacies can exist in the resource allocation systems, and it is difficult to meet the resource requirements of all agents simultaneously. To overcome these difficulties, we propose a distributed multiagent resource allocation system that emphasizes the issues of agents trust and resource inadequacies, which is called MARA-T&R. In this system, the evidence theory is improved thanks to the Deng entropy to estimate the trustworthiness of agents. Additionally, we use the concept of reservations to solve the problem of resource inadequacies. Our simulation results highlight the excellent performances of this improved trust model and the efficiency of the proposed MARA-T&R system for resource allocation. Ningkui Wang, Hayfa Zgaya, Philippe Mathieu, Slim Hammadi |
SMC | 4 |
| 2019 | An Innovative System to Assist the Mobility of People With Motor DisabilitiesabstractPeople with motor disabilities require assistance for navigating form one location to another. In order to improve the integration of wheelchair users into their daily life and work, we propose a real time adaptive planning algorithm for routing the user through an obstacle free optimal path. Our application is based on an augmented reality system for the assistance of wheelchair people (ARSAWP) and uses augmented reality (AR) smart glasses. The main goal is to support the development of indoor and outdoor navigation systems devoted to wheelchair users. In this paper we detail the design, the implementation and the evaluation of the proposed application, which was implemented in java for the Android operational system. Two types of database are used (local database and remote database). The information about navigation is displayed on AR glasses which give the user the possibility to interact with the system according to the external environment. The prototype is designed for use within the University of Lille campus. Faiza Ajmi, Sawssen Ben Abdallah, Sarah Ben Othman, Hayfa Zgaya, Slim Hammadi |
SMC | 5 |
| 2018 | Patient Pathway Workflow Model Identifying Overcrowding Indicators in Emergency Department
Faten Ajmi, Sarah Ben Othman, Hayfa Zgaya, Slim Hammadi |
SIMULTECH | 4 |
| 2017 | A Multi-Agent Advanced Traveler Information System for Optimal Trip Planning in a Co-Modal FrameworkabstractWe present an advanced traveler information system (ATIS) for public and private transportation, including vehicle sharing and pooling services. The ATIS uses an agent-based architecture and multi-objective optimization to answer trip planning requests from multiple users in a co-modal setting, considering vehicle preferences and conflicting criteria. At each set of users' requests, the transportation network is represented by a co-modal graph that allows decomposing the trip planning problem into smaller tasks: the shortest routes between the network nodes are determined and then combined to obtain possible itineraries. Using multi-objective optimization, the set of user-vehicle-route combinations according to the users' preferences is determined, ranking all possible route agents' coalitions. The ATIS is tested for the real case study of the Lille metropolitan area (Nord Pas de Calais, France). Mariagrazia Dotoli, Hayfa Zgaya, Carmine Russo, Slim Hammadi |
IEEE Trans. Intell. Transp. Syst. | 4 |
| 2016 | Multi-Hop Ridematching optimization problem: Intelligent chromosome agent-driven approach
Sondes Ben Cheikh, Slim Hammadi |
Expert Syst. Appl. | 2 |
| 2016 | Agents endowed with uncertainty management behaviors to solve a multiskill healthcare task scheduling
Sarah Ben Othman, Hayfa Zgaya, Slim Hammadi, Alain Quilliot, Alain Martinot, Jean-Marie Renard |
J. Biomed. Informatics | 3 |
| 2015 | Mapping patient path in the Pediatric Emergency Department: A workflow model driven approach
Inès Ajmi, Hayfa Zgaya, Lotfi Gammoudi, Slim Hammadi, Alain Martinot, Régis Beuscart, Jean-Marie Renard |
J. Biomed. Informatics | 4 |
| 2014 | A robust assessment of effective healthcare demand in the Pediatric Emergency DepartmentabstractThis work aims to assess the effective demand of healthcare treatment load in the Pediatric Emergency Department (PED) as a treatment time requested and focus on the treatment time remained. So we defined a metrics assessing the Total Demand Load (TDL) of healthcare treatment in the PED which is more robust to reflect the whole patients' healthcare demand than the simple attending patients count. In addition, we demonstrate that we have to avoid being limited on the physical presence of patients because a high occupancy rate does not necessarily mean that there is a high demand of healthcare treatment. This study was based on Length Of Stay (LOS) estimation according to the patient diagnostic and his number of additional tests. The patient process progression is modeled by a time buffer system allowing the instantly track of each patient. It is a way to improve the quality of service and information delivery. This method offers a priority mechanism, it is also a robust management and decision aided tool. Besides, the time buffers system will encourage physicians to respect the time needed for each patient profile suggested in order to maximize the objective of improving the performing. Such system will make them aware about three important points: The healthcare Treatment process progress, the eventual overflowing/ time excess, the eventual high acuity. From patients' viewpoint, it will reassure parents who can follow the healthcare treatment progression of their children instantly. Wided Chandoul, Hervé G. Camus, Nesrine Zoghlami, Slim Hammadi, Alain Martinot |
CoDIT | 4 |
| 2014 | Mapping patient flow in the Jeanne de Flandres Hospital's operating roomsabstractThe purpose of this paper is twofold: to depict the patient's journey in operating block of the hospital and to provide a flexible model that matches the reality. In operating block of Jeanne de Flandres Hospital, a daily meeting is held in order to establish the operations that will occur the next day. Organizing a schedule in these circumstances leads to a loss of time and can often lead to conflictual situations. The overall study objective is therefore to provide an interactive schedule. Hence, we will need to consider parameters such as the type of surgery, patient's age, and their past history. From model analysis, some operation's duration will be estimated. Inès Ajmi, Lotfi Gammoudi, Matthieu Carruel, Hayfa Zgaya, Slim Hammadi, Jean-Marie Renard |
ETFA | 5 |
| 2014 | A Revisited Model for the Real Time Traffic ManagementabstractThe real-time traffic management allow to solve unexpected disturbances that occur along a railway line during
the normal developement of the traffic. The original timetable is restored through the rescheduling process.
Despite the increase of real-time decision support tools for trains dispatchers that enable a better use of rail infrastructure,
real-time traffic management received a limited scientific attention. In this paper, we deal with the
real time traffic management for regional railway networks, mainly single tracks, in which a centralized traffic
control system is installed. The rescheduling problem is presented as a Mixed Integer Linear Programming
Model which resolution allows to carry out the rescheduling process in a very short computational time. Astrid Piconese, Thomas Bourdeaud'huy, Mariagrazia Dotoli, Slim Hammadi |
ICORES | 4 |
| 2014 | The Alliance between Optimization and Multi-Agent System for the Management of the Dynamic Carpooling
Sondes Ben Cheikh, Slim Hammadi |
KES-AMSTA | 2 |
| 2014 | Based-Agent Distributed Architecture to Manage the Dynamic Multi-hop Ridesharing SystemabstractA diverse range of architectures and concepts has been suggested by academic researchers within the theme of ridesharing. Most of these studies have tried to join together two main elements: the need for mobility and the resources used to achieve this action. Based on empty seats in the private cars, rideshare systems allow a substantial number of people to share car rides. If a request can be matched with only one offer, then the problem is called single hop ride matching. It is called multihop ride matching, if a request can be matched with several offers at different times. In this paper, we focus on the Multi-Hop Ride matching Problem (MHRP) which offers more flexible than other forms of ridesharing and proposes more choices for the rider. As a transportation service, the MHRP is generally geographically distributed in dynamic changing environments. With this in mind, and aiming at setting up a distributed architecture through which an optimizing decentralized process should be performed, we propose a distributed software architecture based on communicating agents with different behaviors. The reason for the growing success of agents behaviors technology especially in performing complex tasks and operating with each other to achieve a desired global goal. Sondes Ben Cheikh, Slim Hammadi, Christian Tahon |
NCA | 2 |
| 2011 | An agent-based distributed scheduling for military logisticsabstractThere has been a significant increase in the improvement of response to disasters in crisis management supply chain. Due to their sudden occurrence, these disasters require a consequent quick and efficient response that depends on the ability of logistics systems to generate plans under a variety of constraints. The supply chain studied in this work is a crisis management supply chain, composed of several elements such as transportation means, loading units, suppliers, equipment, resources, persons... We propose an innovative method for solving a distributed delivery scheduling problem, based on a multi-agent system, for the delivery of goods (food, water, clothes, etc.) to the areas affected by the disaster. The covered areas are geographically distributed and partitioned into multiple sub-regions. Each area is assigned a delivery scheduling sub problem. By employing a distributed cooperative framework, we achieved an incorporation of various evaluation parameters in the process of scheduling in order to maintain a high level of synchronization of all the supply chain, and so to insure a better response to the crisis. Ayda Kaddoussi, Nesrine Zoghlami, Slim Hammadi, Hayfa Zgaya |
ISDA | 3 |
| 2011 | An optimized dynamic carpooling system based on communicating agents operating over a distributed architectureabstractThe emergent carpooling phenomenon has known a great success throughout the world [1] thanks to efforts developed in this context. Several of the studied works failed and some of them led to operational systems but not without having many drawbacks. Thus, in this paper, we present our works through which we attempt to remedy those limits mainly aiming at providing users with optimized responses to instantaneously issued queries. For this purpose, we primarily focus on useful concepts to reduce real time carpooling's high complexity. The most important among them are a decomposition process to establish a distributed dynamic graph representing the served network and the multi agent concept to perform parallel Optimized and Distributed Assignment of Vehicles (ODAVe) to users' queries. Manel Sghaier, Slim Hammadi, Hayfa Zgaya, Christian Tahon |
ISDA | 2 |
| 2011 | Distributed architecture for a co-modal transport systemabstractThe co-modality is a new notion introduced by the European commission in 2006. It consists on developing infrastructures and taking measures and actions that will ensure optimum combination of individual transport modes enabling them to be combined effectively in terms of economic, environmental, service and financial efficiency, etc. Including different transport services in one system means that this one must cope with different distributed transport information stored in different location. For these reasons, we propose in this paper a distributed architecture that aims to satisfy transport users by providing them an optimized co-modal itineraries taking in account their constraints and preferences. Karama Jeribi, Hayfa Zgaya, Nesrine Zoghlami, Slim Hammadi |
SMC | 4 |
| 2011 | A preventive anticipation model for crisis management supply chainabstractIn the military, agile and robust military supply chains are key in providing timely responses to support operations in theatre. Supply during peacetime can be managed by proactive logistics plans and classic supply chain management techniques to guaranty the availability of required needs. However, in case of perturbations (time of war, natural disasters...) the need for support increases dramatically and logistics plans need to be adjusted rapidly. To do that, we propose to use anticipation mechanisms. An anticipator uses a world model to construct future predictions about the supply chain and checks whether an undesirable state may be reached. If it is the case, the anticipator adapts his behavior to avoid the actions responsible of this state. In this paper, we focus on the use of anticipation in multi-agent coordination for military logistic planning. We propose de formalize preventive anticipation in the context of a Crisis Management Supply Chain (CMSC). Ayda Kaddoussi, Nesrine Zoghlami, Hayfa Zgaya, Slim Hammadi, Francis Bretaudeau |
SMC | 4 |
| 2008 | An agent oriented information system for itineraries search using web services compositionabstractThis electronic document is a ldquoliverdquo template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document. We are assisting to a significant growth and improvement of the transport information systems, but this still limited to the operators themselves. In fact, As soon as the trip needs one or more transport operator services, the traveler orientation becomes difficult: the trip pacification obliges the traveler to collect information from different transport operator Web sites. The purpose of this work is to develop an agent-based cooperative information system architecture trying to make the existing operators' information system cooperate efficiently to provide users with the optimized route to follow, and to avoid the consultation of several transport Web sites when travelers want to plan their trip. Mohamed Firas Feki, Mohamed Amine Kamoun, Slim Hammadi |
SMC | 3 |
| 2008 | Using an ontology to solve the negotiation problems in mobile agent information systemabstractIn this paper, we address the problem of negotiation process in a multi-agents system by using ontologies. Therefore, we present an ontology solution based on the knowledge management system for semantic heterogeneity. The proposed solution prevents the misunderstanding during the negotiation process though the agents' communications. Our approach aims to facilitate, to automate the communications and to make the agents able to understand each other when using these ontologies. Thus, we propose a general architecture for Negotiation process which uses Ontology-based Knowledge Management System (NOKMS). This architecture consists of three layers: the Negotiation Layer (NL) that describes the negotiation process between the Initiator Static Agents (ISAs) and the Participant Mobile Agents (PMAs) by using suitable ontologies, the Semantic Layer (SEL) contains the semantic translator which uses in the case of misunderstanding of the sent messages between the agents, and the last one is the Knowledge Management Systems Layer (KMSL) which bases on the Intelligent Knowledge Base (IKB) to give the flexibility to our negotiation ontology. We will try to apply our architecture on the Multimodal Transport Information System (MTIS) project where we will use an agent architecture in our proposal NOKMS to improves the execution of negotiation process in multi-agents systems which use different ontologies in order to satisfy the transport customers. Sawsan Saad, Hayfa Zgaya, Slim Hammadi |
SMC | 3 |
| 2008 | Urban Transport Network Regulation and Evaluation: A Fuzzy Evolutionary ApproachabstractThe real-time regulation of urban collective transport traffic is a very delicate problem, particularly in case of appearance of simultaneous disturbances (vehicle's breakdown, strike, demonstration, etc.). Indeed, a regulator (a decision maker) has to carry out difficult tasks that are often inaccessible at the human scale and involve the assistance of a decision support system (DSS). In this paper, we present the main part of this DSS, i.e., the generator and the evaluator of the decision strategies for disrupted transport network regulation. The proposed module is based on a hybrid approach using a fuzzy evaluation method and evolutionary algorithms. It treats the online regulation problem as an optimization one and provides the regulator with evaluated and classified effective decisions by taking into account his/her preferences. Mohamed M. Ould Sidi, Slim Hammadi, Saïd Hayat, Pierre Borne |
IEEE Trans. Syst. Man Cybern. Part A | 2 |
| 2007 | Multi-Agent Multimodal Transport Information System using Mobile Agent Negotiation
Hayfa Zgaya, Slim Hammadi |
RCIS | 2 |
| 2006 | Modeling the emergency path handling And Emergency Department SimulationabstractThe emergency department in a hospital, as its name implies, is a facility to be utilized by those who require emergency medical care. This paper introduces the longitudinal organization of the patient handling called "emergency path" and it discusses the application of the company modelling methods especially the GRAI methodology in the emergency department. The goal is to optimize these paths and to improve the quality of the patient handling while mastering the costs. The development of this model was based on the ED and three geriatrics, neurology and traumatology services. Simulation was used in this paper to assess the effects of some changes at the ED of the Medical Center of Valenciennes in France. Our survey is integrated into the regional project whose theme are the emergency paths that have just been created at the ED of Valenciennes Hospital center and will contribute to the ED service project achievement. Besma Glaa, Slim Hammadi, Christian Tahon |
SMC | 2 |
| 2006 | Hierarchic Decision Support System approach with evaluation of decision classes of a traffic network transportationabstractThe management of the urban traffic is not an easy task seen the uncertain character of the information in possession of the decision makers. Continually their stake is to bring back the situation of the traffic from a disturbed mode to a normal one while keeping a quality of service and while respecting the constraints of infrastructure, human resources, security and availability of materials. For that, they have to proceed by collecting necessary data, analyze, evaluate and decide of the action to be engaged, while respecting the time constraints and the offer promised to users of network transportation. Asma Melki, Slim Hammadi |
SMC | 2 |
| 2005 | Lower Bounds In An Hybrid Evolutionary Approach For The Pickup And Delivery Problem With Time WindowsabstractIn the single-vehicle pickup and delivery problem with time windows (1-PDPTW), a vehicle must serve a collection of transportation requests by taking loads from providers to customers satisfying precedence, capacity and time constraints. In this paper, we present a brief scientific literature review on the 1-PDPTW and we propose an evolutionary approach, based on lower bounds, to solve this problem. Our evolutionary approach uses an evolutionary algorithm, with special genetic operators to minimize computing time and Pareto dominance method to provide a set of satisfying and feasible solutions to the 1-PDPTW, minimizing the compromise between total travel distance and total tardiness time Ryan Kammarti, Slim Hammadi, Pierre Borne, Mekki Ksouri |
SMC | 2 |
| 2005 | An Agent-Based Cooperative Information System for Multi-modal Travelers Route ComputationabstractA wide and growing variety of transport's useful information systems and services are becoming available daily to assist travelers, but technical supports for discovering, selecting and integrating these resources are still limited. This is due to several reasons of different types: organizational, economic, juridical, technical and quality reasons. The purpose of this study was, essentially, to suggest an agent-based cooperative information system for multi-modal transport's travelers, trying to make the existing information system cooperate efficiently to provide travelers with multi-modal and multi-operator information itinerary involving different means of transport and several operators. More precisely, this agent-based cooperative information system has essentially for its aim to calculate the shortest itinerary in terms of distance, time, and cost, to assist travelers Mohamed Amine Kamoun, Guillaume Uster, Slim Hammadi |
SMC | 3 |
| 2005 | Evolutionary method to optimize workplan mobile agent for the transport network applicationabstractThis paper explains how to optimize the workplans of mobile agents (MAs) in order to enhance their performance. A MA travels through transport network looking for useful information and services. This information should be available daily to assist travelers to use multimodal transportation system. Our objective is to maximize the number of satisfied transport travelers. In other words, we attempt to increase the satisfaction of transport customers during their travels. So, we intend to optimize task assignment to a set of servers which can offer information with preset cost and processing time. With this intention, we adopted an approach based on evolutionary programs in order to solve our combinatorial problem. Therefore, it is very important to design an efficient representational scheme of a chromosome and develop effective genetic operators. We create a new representation of the chromosome where we integrated the constraints of our problem Hayfa Zgaya, Slim Hammadi, Khaled Ghédira |
SMC | 2 |
| 2003 | Decision support system for urban transportation networksabstractThis paper deals with the real-time regulation of traffic within a disrupted transportation system. We outline the necessity of a decision support system that detects, analyzes, and resolves the unpredicted disturbances. Due to the distributed aspects of transportation systems, we present a multi-agent approach for the regulation process. Moreover, this approach also includes an evolutionary algorithm that is based on an original genetic coding representing the decisions on a set of vehicles and stops affected by the disturbance. This set constitutes, in fact, the space-time horizon of the regulation process. The evolutionary algorithm then treats the regulation problem as an optimization and provides the regulator with relevant decisions that can result in a partial reconfiguration of the network. Pierre Borne, Besma Fayech, Slim Hammadi, Salah Maouche |
IEEE Trans. Syst. Man Cybern. Part C | 3 |
| 2003 | A distributed scheduling for agro-food manufacturing problemsabstractWorkshop scheduling problems can be considered as one of the main factors to improve the productivity and efficiency of a manufacturing system. The continuous evolution and the dynamic characteristics of industrial workshops, particularly those of agro-food industries, impose the generation of a real time decision scheduling process. In the agro-food industries, the products to be processed and the used primary products are characterized by their limit validity dates which generate some particularly and especially antagonist criteria. A distributed decision support system for real time scheduling is described in this paper. It is based on an original cooperative approach aimed to elaborate robust decisions that propose to the "best action" to the decision maker. The decision process is distributed all along the production chain. At each decision time, in order to ensure coherency, we have to take into account the neighborhood constraints in order to simultaneously satisfy different criteria which do not have the same importance. An aggregation criteria system is defined to manage the criteria among their importance degrees. We define a decisional model based on the evaluation and the comparison of a set of proposed actions. E. Gargouri, Slim Hammadi |
IEEE Trans. Syst. Man Cybern. Part C | 2 |
| 2003 | Special issue on intelligent techniques in flexible manufacturing systems
Slim Hammadi, Christian Tahon |
IEEE Trans. Syst. Man Cybern. Part C | 1 |
| 2002 | An hybrid approach for a supply chain management in agro-food industriesabstractIn the agro-food environment, many particular constraints and criteria have to be met by the supply chain managers. In fact the seasonality and the fluctuations of the demand, the short life cycle of the used and produced products, and the irregularity of the primary products supply make the implementation of the classical production process and inventory control such as the Economic Order Quantity EOQ and the Just In Time (JIT) systems inefficient and unsuccessful. Therefore, we propose in this paper an hybrid approach "The extend kanban approach for the agro-food manufacturing" which is based on the cooperation between the principles of the JIT system and the statistical process control. Establishing "the extend kanban approach" in the agro-food reduces production cost by minimizing the production lot size and permits to maintain at the same time an authorized stock level which allows to take face to the eventual demand fluctuation. E. Gargouri, Slim Hammadi |
SMC | 2 |
| 2002 | Decision support tool for a location problem based on a genetic algorithmabstractThis paper considers the problem of locating the GDF (Gaz de France) bases of the French gas board in a geographical region in order to supervise and to maintain a set of stations and gas pipe lines with specific security and efficiency levels where some GDF base locations can be fixed a priori. The location problem reduces to a classical location allocation problem with additional side and security constraints. To solve the location problem we propose a genetic algorithm where solutions are evaluated based on their cost, their security and their efficiency levels. The genetic algorithm is embedded within a decision support tool to generate acceptable solutions to the decision maker. The decision support tool allows the decision maker to be involved in the decision process by setting the parameters of the location problem and the parameters of the genetic algorithm such as the initial population and the stopping criterion. Mariem Gzara, Slim Hammadi, Pierre Borne |
SMC | 2 |
| 2002 | Pareto-optimality approach based on uniform design and fuzzy evolutionary algorithms for flexible job-shop scheduling problems (FJSPs)abstractIn our previous work (2002), we have proposed a Pareto-optimality approach for solving multiobjective optimization problems (MOPs) based on the hybridization of fuzzy logic and evolutionary algorithms (EAs). Such an approach makes it possible to construct a set of satisfactory solutions in order to provide flexibility to the decision-maker. In this work, we aim to enhance the suggested approach and propose a new variant of such a hybridization. Thereafter, we show how a uniform design can be used for finding a set of Pareto optimality solutions uniformly scattered. We briefly describe the Pareto-optimality concepts used for solving MOPs and those especially applied in EAs. Then, the mathematical formulation of FJSP is presented. The proposed hybrid approach is described. We illustrate the suggested approach by applying it to solving FJSP and highlights some practical aspects of the application of such an approach for solving hard combinatorial problems. Finally, we conclude with some future research directions. Imed Kacem, Slim Hammadi, Pierre Borne |
SMC (2) | 2 |
| 2002 | Approach by localization and multiobjective evolutionary optimization for flexible job-shop scheduling problemsabstractTraditionally, assignment and scheduling decisions are made separately at different levels of the production management framework. The combining of such decisions presents additional complexity and new problems. We present two new approaches to solve jointly the assignment and job-shop scheduling problems (with total or partial flexibility). The first one is the approach by localization (AL). It makes it possible to solve the problem of resource allocation and build an ideal assignment model (assignments schemata). The second one is an evolutionary approach controlled by the assignment model (generated by the first approach). In such an approach, we apply advanced genetic manipulations in order to enhance the solution quality. We also explain some of the practical and theoretical considerations in the construction of a more robust encoding that will enable us to solve the flexible job-shop problem by applying the genetic algorithms (GAs). Two examples are presented to show the efficiency of the two suggested methodologies. Imed Kacem, Slim Hammadi, Pierre Borne |
IEEE Trans. Syst. Man Cybern. Part C | 2 |
| 2002 | Correction to "approach by localization and multiobjective evolutionary optimization for flexible job-shop scheduling problems"abstractInternational audience Imed Kacem, Slim Hammadi, Pierre Borne |
IEEE Trans. Syst. Man Cybern. Part C | 2 |
| 2001 | Urban bus traffic regulation by evolutionary algorithmsabstractThe most important disadvantage of urban bus networks (UBN) is their close dependence on diverse random phenomena that can alter the initial preestablished schedules of the buses. In fact, any changes occurring in the global urban traffic, in the demand, in the equipment or in the stuff, may certainly cause disturbances within the network traffic. Moreover, these disturbances affect the waiting time of the customers at the stops, the transit operations and also the duration of the different trips on the buses. This article deals with the traffic regulation in an UBN, especially with the transit operations. After introducing the considered disturbances, we state the different criteria that have to be optimized. The regulation approach by evolutionary algorithms is then exposed and some simulation results are presented. Besma Fayech, Slim Hammadi, Salah Maouche, Pierre Borne |
SMC | 2 |
| 2001 | Approach by localization and genetic manipulation algorithm for flexible job-shop scheduling problemabstractTraditionally, assignment and scheduling decisions are separately made at different levels of the production management framework. The combining of these decisions presents additional complexity and new problems. We present two approaches to solve the assignment and job-shop scheduling problems (with total or partial flexibility). The first one is the approach by localization : it makes it possible to solve the problem of resources allocation and build an ideal assignments model (assignments scheme). The second one is an evolutionary approach controlled by the assignments model (generated by the first approach). In this approach, we apply advanced genetic manipulations in order to enhanced solutions quality. We Also explain some of the practical and theoretical considerations to the construction of a more robust encoding that will allow us to consider the sequencing and the assignment problems jointly. Imed Kacem, Slim Hammadi, Pierre Borne |
SMC | 2 |
| 2000 | A controlled genetic algorithm by fuzzy logic and belief functions for job-shop schedulingabstractMost scheduling problems are highly complex combinatorial problems. However, stochastic methods such as genetic algorithm yield good solutions. In this paper, we present a controlled genetic algorithm (CGA) based on fuzzy logic and belief functions to solve job-shop scheduling problems. For better performance, we propose an efficient representational scheme, heuristic rules for creating the initial population, and a new methodology for mixing and computing genetic operator probabilities. Sonia Hajri, Noureddine Liouane, Slim Hammadi, Pierre Borne |
IEEE Trans. Syst. Man Cybern. Part B | 3 |
| 1998 | Traffic regulation modeling for a subway line with double loopsabstractThis paper explain why and how to implement the double loops service in the automatic subway of Lille, France. This double loops service is characterized by the presence of more possible circuit for the train. The system permits one to serve some portions of the lines, which have some high density of population. We explain how to solve the different problems caused by traffic perturbation. Khaled Mesghouni, Saïd Hayat, Slim Hammadi, Pierre Borne |
SMC | 3 |