Antonio Boccalatte

Performance Evaluation of an Adaptive Ant Colony Optimization Applied to Single Machine Scheduling

We propose a self-adaptive Ant Colony Optimization (AD-ACO) approach that exploits a parameter adaptation mechanism to reduce the requirement of a preliminary parameter tuning. The proposed AD-ACO is based on an ACO algorithm adopting a pheromone model with a new global pheromone update mechanism. We applied this algorithm to the single machine total weighted tardiness scheduling problem with sequence-dependent setup times and we executed an experimental campaign on a benchmark available in literature. Results, compared with the ones produced by the ACO algorithm without adaptation mechanism and with those obtained by recently proposed metaheuristic algorithms for the same problem, highlight the quality of the proposed approach.

AgentService: a framework to develop distributed multiagent systems

This paper presents AgentService, a framework for developing Multiagent Systems (MAS). The key features introduced with AgentService are a flexible agent model and a modular platform. Agents can perform multitask activities as well as move among different platforms. The MAS is hosted in a modular environment so that the platform can be customised. Several tools come with the programming suite, in particular: a visual protocol designer and a set of language extensions integrated into a professional development environment to ease development.

An object-oriented modeling approach based on entity-relationship diagrams and Petri nets

Information systems (ISs) development process is usually characterized by several phases, among which a critical role is played by conceptual and logical design. To model static information structures, entity-relationship (ER) diagrams are probably the widespread formalism. To represent dynamic information, Petri nets are a flexible formalism as they are able to model processes from an aggregate point of view to a very detailed one. The purpose of this work is to try to integrate these two different formalisms in order to allow an automatic translation of conceptual models of process into a relational structure. Then, the functionality of an RDBMS could be extended by including in the relational database also a representation of dynamic information, and allowing the RDBMS to directly control the process execution.

A multi-agent approach to support dynamic scheduling decisions

This work concerns the use of multi-agent system models as a paradigm to support dynamic scheduling decisions. A dynamic class of scheduling problems has been considered, and a just-in-time manufacturing production has been assumed. In particular, the problem of scheduling independent jobs on identical parallel machines, to optimise a non-regular objective, including both job earliness and tardiness penalties, has been faced. Different classes of agents compose the multi-agent scheduling system, and a schedule is progressively defined by a negotiation protocol among the agents associated with the jobs and the machines.

A multiuser groupware calendar system based on agent tools and technology

In this paper MATT, a groupware calendar system (GCS), is presented. The MATT system provides users with a shared calendar service by preserving the right to the privacy and also by presenting features for arranging meetings automatically. The core of the proposed GCS system is a multiagent infrastructure. The shared calendar is managed automatically as well as the process of arranging meeting resulting in an effective tool. An advanced network management system allows MATT to be functional regardless if the connection is present or not

A CASE tool for information system project and development

Presents a project to develop a tool to support the design of information systems and the development of the first prototype, which can define the dynamic parts of information systems. The purpose is to develop a CASE tool that can be used even by semi-inexperienced users (i.e. users without particular knowledge of the logical and physical structuring of an IS). The Information System Design Support system (ISYDES) has two main parts: one allows the definition of the static structure of data through a simple conceptual model which can be directly translated into a relational one (to this end, an object-oriented generalization of an entity-relationship diagram is proposed), whereas the other allows the definition of functions, which constitute the dynamic part of an IS, through a simple graphical formalism (based on UML activity diagrams). Attention is focused on the second part of the tool. The formalism adopted is described in detail, and the procedure that transforms the formalism into a labelled and controlled Petri net is presented. All the dynamics of an IS are provided for by Petri nets as they can be embedded into the relational database management system through their representation in terms of relations.

Autonomous Agents Applied to Manufacturing Scheduling Problems: A Negotiation-Based Heuristic Approach

In this paper, a heuristic approach to job scheduling, which is based on a multi-agent system model, is proposed. The class of scheduling problems considered is characterized by the presence of independent jobs and identical parallel machines, and by a non-regular objective, including both job earliness and tardiness penalties. The multi-agent scheduling system is composed by different classes of agents, and a schedule is progressively defined by a negotiation protocol among the agents associated with the jobs and the machines.

ISYDES: the project of a tool aimed at information system development

Illustrates the main functionalities and development methodologies of the ISYDES (Information SYstem DEsign Support) system, which is a CASE tool for information system (IS) design and development. Such a tool is mainly composed of two software tools: the first allows the definition of the static structure of data, whereas the second allows the complete specification of all the functions which constitute the dynamic part of an IS. This second step is very important in the design phase of an IS, as all the IS operations and processes are based on the specification of such functions. The proposed ISYDES tool adopts an object-oriented approach to the IS conceptual design; in particular, it provides a way to specify the information processes that can be easily translated into the actual IS-coded procedures.

An approach to information system management based on relational databases and Petri net integration

In this paper the Information System management problem is considered, with special reference to the ones which model Flexible Manufacturing Systems. An approach based on Relational Databases and Petri net integration is presented: the former are used to represent passive and static information whereas the latter to model working processes of information inside the Information System. In the presented solution also Petri nets are modeled by means of relations in order to make totally homogeneous the whole Information System structure.

A hybrid system for short-term scheduling in manufacturing: a case study

In this paper a system for dealing with short-term scheduling problems in manufacturing is presented. The system has a hybrid architecture since it integrates a module based on a numerical scheduling algorithm with a knowledge-based module. The system is designed to deal with the scheduling problems which, due to the complexity of the operational conditions involved cannot be solved in an acceptable way by a reliable numerical algorithm. The approach proposed is that of generating a starting solution to a simplified version of the real problem by means of a numerical algorithm, and then modifying such a solution by the knowledge-based module in order to satisfy the real conditions. A case study which illustrates such an approach is presented.<<ETX>>