Omar López-Ortega

A STEP-based manufacturing information system to share flexible manufacturing resources data

The paper describes the design and implementation of a Manufacturing Information System as a solution to share and exchange manufacturing data. The Manufacturing Information System possesses relevant features for data sharing and exchanging, that are compliant to the standard ISO 10303, known as STEP1. It is known that manufacturing planning and execution activities require data from machine-tools, robots, ASRSs2, AGVs3 and, on the other hand, computer-based applications (CAM4, CAPP5 or PAC6) use proprietary formats to store flexible manufacturing resources data. The way the proprietary formats are built has lead to incompatibilities and interoperability problems among the applications. It is argued that by solving these problems a qualitative functional synergy will result during manufacturing planning and execution activities. The suggested solution is using a STEP-based information system, a server and a prototype client application. These three programs are implemented in Java classes to facilitate data sharing and exchanging of flexible manufacturing resources.

JAPIEST: An integral intelligent system for the diagnosis and control of tomatoes diseases and pests in hydroponic greenhouses

Automated Hydroponic Greenhouses represent novel food production systems which include modules for supervising the cultivated soil, packaging plans, as well as prevention, diagnosis and control of pests and diseases. In this setting, we propose the design and implementation of an Integral Intelligent System called JAPIEST, which is focused on the prevention, diagnosis and control of diseases that affect tomatoes (Licopersicum exculentum). Plants are farmed inside hydroponic greenhouses, whose particular conditions of temperature, humidity and nutrient consumption rates can influence directly the surge of plagues or diseases. It is relevant to detect and control the occurrence of any given pest or disease because plants are utterly sensitive to variations of environmental conditions and they have a short induced lifecycle. JAPIEST is a novel and valuable tool for farmers to make an early decision of the candidate disease, and then apply a suitable control treatment, based on Integrated Pest Management.

An agent-oriented decision support system combining fuzzy clustering and the AHP

Decision making is a complex process, particularly when it is carried out by multidisciplinary team. Methods based on the analytical hierarchy process have been widely employed because they provide solid mathematical background. Nevertheless, solutions such as the Aggregation of Individual Judgements (AIJ) and the Aggregation of Individual Priorities (AIP) do not offer sufficient explanatory data in regards with the final decision. We developed an agent-based decision support system (DSS) that employs fuzzy clustering to group individual evaluations and the AHP to reach a final decision. Fuzzy clustering is adequate to determine important pieces of data such as the largest group of evaluations that exist around a centroid value. On the other hand, the MAS paradigm offers capabilities for achieving distributed and asynchronous processing of data. The AHP is used after the individual evaluations are clustered, as if the group were a single evaluator. Altogether, the proposed solution enhances the quality of multi-criteria group decision making.

A distributed semantic network model for a collaborative intelligent system

A methodology based on topology theory to model a semantic network for a collaborative system is given. This framework is used to support the creation of a semantic network and to define the associated intelligent cooperative system. Our methodology is illustrated via a set of agents whose knowledge-base is a semantic network. By a series of functions applied on a base of entities, issued from the application domain, a family of sets are synthesized with their subspaces correlated. The resultant subspaces and their relations form a network of elementary and complex concepts that can be naturally represented with the IDEF1x language. A prototype Multi-Agent System (MAS), set up with the Zeus platform,1 was developed for the Process Plan domain, which was used as a case study. Full correspondence among the subspaces, the semantic network IDEF1x information model and the MAS implementation is obtained by employing this framework.

A formal framework to integrate express data models in an extended enterprise context

The paper describes a formal framework to integrate EXPRESS models and facilitate sharing and exchanging of data in an Extended Enterprise context. We perceive in the creation of an Extended Enterprise an opportunity to use standardized data models. Hence our research is based on three important ISO standards whose primary objective is to enhance data exchange. These standards are ISO 10303, ISO 15531 and ISO 13584, known as STEP, MANDATE and PLIB, respectively. Although they are intended to overcome incompatibility problems for the computer-based applications that are used during the product life-cycle, they turned out to be semantically incompatible among themselves. This seems to be a major drawback when individual organizations want to share core competences, such as resources, manufacturing processes, or product design, to create an Extended Enterprise. The constructs we propose harmonize incompatible model components so that core competences can be transparent to the net of enterprises. The proposal is exemplified by creating a mediator application and a repository. The mediator application is used by individual firms to gain access to the core abilities that are shared, whereas the repository is a neutral means to store such competences. It complies with part 21 of the ISO 10303 standard. The proposed formal framework provides a sound model of the information system and facilitates data sharing in the Extended Enterprise.

Computer-assisted creativity: Emulation of cognitive processes on a multi-agent system

For creativity to be computed, it is paramount to understand the cognitive processes involved, which have been elucidated by either surveying creative people or discovering regions of the human brain that activate during creative endeavors. From this scattering, the author proposes a holistic framework to describe them and their interaction. Hence, creativity can be regarded as a meta process which coordinates autonomous cognitive processes such as planning or divergent thinking. To represent the interplay of cognitive processes around creativity, models are developed in the Agent Unified Modeling Language (AUML). Then, the execution of each process is delegated to autonomous agents and a global coordination protocol is devised. The implementation of the MAS is done on the JADE platform. Two modules of the resultant system are exemplified: opus planning and divergent exploration. The coordination protocol is also presented. The domain in which the software system is tested is the creation of musical pieces.

Intelligent and collaborative Multi-Agent System to generate and schedule production orders

The authors present a Multi-Agent System for constructing and releasing production orders. In a manufacturing enterprise, the generation of production orders consists in a set of coordinated tasks among departments. This has been achieved traditionally as a module of the Production Activity Control (PAC) system. However, classic PAC modules lack collaborative techniques and intelligent behaviour. Moreover, in real-life situations experienced planners take over traditional PAC systems, since the range of possibilities to actually build production orders increases exponentially. To contribute to production planning, we present an intelligent and collaborative Multi-Agent System (MAS), having coordinated two forms to emulate intelligence. The learning capability is achieved by means of a Feed-forward Artificial Neural Network (FANN) with the back-propagation algorithm. The FANN is embedded within a machine agent whose objective is to obtain the appropriate machine in order to comply with requirements coming from the sales department. Also, an expert system is provided to a tool agent, which in turn is in charge of inferring the right tooling. The MAS also consists of a coordinator and a spy. The coordinator agent has the responsibility to control the flow of messages among the agents, whereas the spy agent is constantly reading the Enterprise Information System. Finally, a scheduler agent schedules the production orders. The resultant MAS improves the current form to plan production in a factory dedicated to produce labels.

Java Fuzzy Kit (JFK): A shell to build fuzzy inference systems according to the generalized principle of extension

In this article the author presents JFK, which stands for Java Fuzzy Kit. JFK is an Application Programming Interface (API) that complies with both, a general structure of a fuzzy rule base and the necessary processing to compute the generalized principle of extension. A recurrent structure is found for a class of fuzzy expert systems, known as the Mamdani model. This leads to claim that a design pattern exists, since core objects, which are present regardless the specific application are identified. However, there is not a general shell to build fuzzy expert systems, and this provokes that current fuzzy expert systems are build on an ad-hoc basis. The modelling of JFK is done according to the Unified Modelling Language specifications. Along with the UML modelling three important algorithms are described, which serve to perform the generalized principle of extension. The usage of JFK is illustrated with an example, namely the ranking of swimmers. Preliminary results on this study case are the basis to propose the realization of fuzzy distributed decision systems. This goal is accomplished by providing agents with fuzzy expert systems, with the integration of JFK and the standardized platform JADE (Java Agent Development Environment).

Fractals, fuzzy logic and expert systems to assist in the construction of musical pieces

The authors present a suite to assist in the creation of musical pieces, whose foundation lies on fractals, fuzzy logic and expert systems. Even though algorithmic music has been explored, some gaps still exist. The favored approach has consisted in mapping numbers to notes to create appealing pieces. This, we contend, is a necessary but not a sufficient condition. Our suite, besides the necessary mapping, possesses the following advantages. First, it is possible to define notes, tempos, and notes durations. Notes evolve according to the selected fractal. Tempos and durations can remain fixed or they also can follow a fractal. Second, it is possible to translate the resultant fractal notes into notes belonging to a musical scale. This is done by firing appropriate rules in a rule base. Third, interpretation templates are provided. Also, melodies or harmonies are available. The suite currently contains several known fractal systems, and we also proposed one dynamical, recursive computation based on Mamdani fuzzy rule bases. The suite we present helps promoting and monitoring the creative process of composing musical scores. The actual implementation of the suite was done on the Java language.

Cognitive communication in a multi-agent system for distributed process planning

This paper presents a framework for modelling and realisation of a Multi-Agent System (MAS) aimed at process planning. Firstly, the concepts of an ontology are constructed and partial subtasks are defined. Secondly, a knowledge base is implemented, regarding the relations stated in the ontology. Finally, a cooperative system is set that will establish speech acts to achieve the system goal by completing subtasks. The communication of knowledge and the achievement of subtasks are illustrated by two intelligent agents. They maintain a communication process that is inititated by a Part Agent. Once the message is formed, a response is obtained from the Operation Agent. The strength of this proposal is shown with the implementation of the MAS, in connection with a rule-based system.