15338420
Aspectizing Multi-agent Systems: From Architecture to Implementation
Agent architectures have to cope with a number of internal properties (concerns), such as autonomy, learning, and mobility. As the agent complexity increases, these agent properties crosscut each other and the agent’s basic functionality. In addition, multi-agent systems encompass multiple agent types with heterogeneous architectures. Each of these agent types has different properties, which need to be composed in different ways. In this context, the separation and the flexible composition of agent concerns are crucial for the construction of heterogeneous agent architectures. Moreover the separation of agent concerns needs to be guaranteed throughout the different development phases, especially from the architectural to the implementation phase. Existing approaches do not provide appropriate support for the modularization of agent properties at the architectural stage, and do not promote a smooth transition to the system implementation. This paper presents an aspect-oriented method that allows for a better separation of concerns, supporting the systematic aspectization of agent properties through the architectural definition, detailed design and implementation. A multi-agent system for paper reviewing management is assumed as a case study through this paper to show the applicability of our proposal.
45365979
Software Engineering for Multi-Agent Systems
9474173
Improving modularity of reflective middleware with aspect-oriented programming
Reflective middleware has been proposed as an effective way to enhance adaptability of component-oriented middleware architectures. To be effectively adaptable, the implementation of reflective middleware needs to be modular. However, some recently emerged applications such as mobile, pervasive, and embedded applications have imposed more stringent modularity requirements to the middleware design. They require support for the conception of a minimal middleware while promoting finegrained modularity of reflective middleware features. The key problem is that fundamental mechanisms for decomposing reflective middleware implementations, such as object-oriented ones, suffer from not providing the proper means to achieve the required level of localizing reflection-specific concerns. This paper presents a systematic investigation on how aspect-oriented programming scales up to improve modularity of typical reflection-specific crosscutting concerns. We have quantitatively compared Java and AspectJ implementations of an OpenORB-compliant reflective middleware using separation of concerns metrics.
39578766
On the Quantitative Assessment of Modular Multi-Agent Architectures
12082403
Improving Extensibility of Object-Oriented Frameworks with Aspect-Oriented Programming
Object-oriented frameworks are nowadays a common and useful technology used in the implementation of software system families. Despite their benefits, over the last years many researchers have described the inadequacy of object-oriented mechanisms to address the modularization and composition of many framework features, thus reducing the extent to which a framework can be extended. The crosscutting nature of many framework features is identified as one of the main causes of these problems. In this paper, we analyze how aspect-oriented programming can help to improve the design, implementation, and extension of object-oriented frameworks. We propose the concept of Extension Join Points (EJPs) as a way of designing and documenting existing crosscutting extension points. EJPs improve framework extensibility, including superior composability of the framework core functionality with other modules or frameworks. Four case studies of frameworks from diverse domains are presented to illustrate our proposal. This paper also discusses lessons learned on the application of our approach to the development and extension of these frameworks.
979214
Enhancing agent-oriented models with aspects
The modular representation of concerns is imperative in the design modeling of multi-agent systems (MASs). However, MAS designers typically face a number of concerns that inherently affect several system agents and their respective internal elements, such as actions and goals. These crosscutting concerns encompass both internal and systemic properties, such as learning, mobility, error handling, and security. Without an explicit modeling of such MAS properties, designers can not properly communicate and reason about them and their broadly-scoped effects. The result is a multitude of agent-oriented design breakdowns: poor traceability from requirements to design models, hindering of reuse opportunities, and decreased evolvability. This paper presents an enhancement of an existing agent-oriented modeling language with aspects. We illustrate the use of our approach through some classical examples of crosscutting concerns in agent-oriented design models.
17377991
Applying the HYRIWYG incentive mechanism in a recommender system
The use of recommender systems (RS) has become common in several e-commerce Web sites. Collaborative filtering is one of the most popular RS techniques. It infers a user's predilections based on similarity with other users. However, to work correctly, the RS depends on the evaluator's participation with truly opinions. The HYRIWYG mechanism proposes an incentive model to motivate users to contribute with a high number of opinions and, more important, guaranteeing the truthfulness of the information. In this paper, we present HYRIWYG mechanism and discuss it using an empirical study in the movie evaluation domain. Initial results highlight the great potential benefits of using this kind of incentive mechanism.
5520687
Web Navigation Patterns
44575256
An X-Ray of the Brazilian e-Gov Web Sites
The digital inclusion promotes the reduction of social inequalities. Based on this principle, the Brazilian Government has been setting up an increasing number of Web access locations to render virtual support to its citizens. However, there are no guidelines for the construction and assessment of these electronic Government (e-Gov) sites. In this article we measure the web site quality in the e-Gov domain with the following proprieties: usability, accessibility, interoperability, security, privacy, information reliability, and service agility. We implemented our method, by using a checklist tool, in the evaluation of 127 Brazilian government sites (federal, state and municipal). Our method proved itself efficient in the diagnosis and identification of specific problems in the e-Gov site domain.
6083238
A Multiagent System Applied to the Design of Petroleum Off-Shore Platforms
This paper presents a model for cooperative multi-agents that interact in a closed environment, i.e., an environment where the rules are well known by the agents and do not change dynamically. In a computational environment where several different software agents share resources to reach their goals, the occurrence of conflicts is inevitable. Therefore it is of highest importance to have an efficient mechanism to solve such conflicts. While other models in the literature present solutions for conflict resolution based on centralized and distributed algorithms, our proposal is to solve the conflicts in a hierarchical manner. The proposed model is based on the application of Social Laws and it was inspired by the theory of Jean Jacques Rousseau’s Social Contract, being denominated Tri-Coord Model, that is, of Triple Coordination. We implemented a prototype based on the Tri-Coord Model, and applied to the task of oil and gas process floorplan design in a petroleum off-shore platform. In that domain the project is divided in several subsystems, with an agent being responsible for each sub-system. Our experiments indicate that the Tri-Coord Model can indeed yield a better performance in the development of a project. First, because it decreases the interruptions for accomplishment of meetings to solve conflicts related to customization of sub-system’s parameters. Second, because it removes the bottleneck associated to a centralized model for conflict resolution. Third, because through the regulator environment of Tri-Coord the agents behavior can be controlled implicitly by the environment. In that way the agents learn how to interact correctly and the independence between the environment and the agents turns the system more flexible.
13425018
Lithofacies recognition hybrid bench
Well offshore petroleum exploration is a risky, but very profitable task. Determining the rock formation of each layer of a given reservoir diminishes the risks of expending a great deal of money drilling dry wells. Since collecting offshore rock samples is difficult and expensive, geologists must decide upon drilling based on indirect measures called well log. Traditional statistical methods have been used to assist this task. Neural networks have also been successfully used. As an alternative fuzzy logic based systems have an extra appeal of intuitive comprehension of some uncertainties. This paper presents a hybrid tool that combines neural networks, fuzzy logic and neuro-fuzzy logic to improve human intuition when analyzing the potential of oil fields.