MACS: Multi-agent COTR system for Defense Contracting

The field of intelligent multi-agent systems has expanded rapidly in the recent past. Multi-agent architectures and systems are being investigated and continue to develop. To date, little has been accomplished in applying multi-agent systems to the defense acquisition domain. This paper describes the design, development, and related considerations of a multi-agent system in the area of procurement and contracting for the defense acquisition community

Congrats: a Configurable Granular Trust Scheme for Effective Seller Selection in an E-marketplace

Problem. The e-marketplace of today, with millions of buyers and sellers who never get to meet face to face, is susceptible to the presence of dishonest and fraudulent participants, prowling on unsuspecting trading partners to cheat in transactions, thereby increasing their profit to the detriment of their victims. There is also the multiplicity of goods and services with varying prices and quality, offered by a mix of honest and dishonest vendors. In order to participate in trade without incurring substantial loss, participants rely on intelligent agents using a trust evaluation scheme for partner selection. Making good deals thus depends on the ability of the intelligent agents to evaluate trading partners and picking only trustworthy ones. However, the existing trust evaluation schemes do not adequately protect buyers in the e-marketplace; hence, this study focused on designing a new trust evaluation scheme for buyer agents to use to effectively select sellers. -- Method. To increase the overall performance of intelligent agents and to limit loss for buyers in an e-marketplace, I propose CONGRATS—a configurable granular trust estimation scheme for effective seller selection. The proposed model used historical feedback ratings from multiple sources to estimate trust along multiple dimensions. I simulated a mini e-marketplace to generate the data needed for performance evaluation of the proposed model alongside two existing trust estimation schemes—FIRE and MDT. -- Results. At the peak of performance of CONGRATS, T1 sellers with the highest trust level accounted for about 45% of the total sales as against less than 10% recorded by the least trustworthy (T5) sellers. Compared to FIRE and MDT, CONGRATS had a performance gain of 15% and 30%, respectively, as well as an average earning of 0.89 (out of 1.0) per transaction in contrast to 0.70 and 0.62 per transaction respectively. Cumulative utility gain among buyer groups stood at 612.35 as contrasted to 518.96 and 421.28 for the FIRE and MDT models respectively. -- Conclusions. Modeling trust along multiple dimensions and gathering trust information from many different sources can significantly enhance the trust estimation scheme used by intelligent agents in an e-marketplace. This means that more transactions will occur between buyers and sellers that are more trustworthy. Inarguably, this will reduce loss to an infinitesimal level and consequently boost buyer confidenc

Aisimam - An Artificial immune system based intelligent multiangent model

The goal of this thesis is to develop a biological model for multiagent systems. This thesis explores artificial immune systems, a novel evolutionary paradigm based on the immunological principles. Artificial Immune systems (AIS) are found to be powerful to solve complex computational tasks. The main focus of the thesis is to develop a generic mathematical model that uses the principles of the human immune system in multiagent systems (MAS). The components and properties of the human immune system are studied. On understanding the concepts of A/5, a literature survey of multiagent systems is performed to understand and compare the multiagent concepts and AIS concepts. An analogy between the immune system parameters and the agent theory was derived. Then, an intelligent multiagent model named AISIMAM is derived. It exploits several properties and features of the immune system in multiagent systems. In other words, the intelligence of the immune systems to kill the antigen and the characteristics of the agents are combined in the model. The model is expressed in terms of mathematical expressions. The model is applied to a specific application namely the mine detection and defusion. The simulations are done in MATLAB that runs on a PC. The experimental results of AISIMAM applied to the mine detection problem are discussed. The results are successful and shows that AISIMAM could be an alternative solution to agent based problems. Artificial Immune System is also applied to a pattern recognition problem. The problem experimented is a color image classification problem useful in a real time industrial application. The images are those of wooden components that need to be classified according to the color and type of wood. To solve the classification task, a simple negative selection and genetic algorithm based A/5 algorithm was developed and simulated. The results are compared with the radial basis function approach applied to the same set of input images

Resilience Model for Teams of Autonomous Unmanned Aerial Vehicles (UAV) Executing Surveillance Missions

Teams of low-cost Unmanned Aerial Vehicles (UAVs) have gained acceptance as an alternative for cooperatively searching and surveilling terrains. These UAVs are assembled with low-reliability components, so unit failures are possible. Losing UAVs to failures decreases the team\u27s coverage efficiency and impacts communication, given that UAVs are also communication nodes. Such is the case of a Flying Ad Hoc Network (FANET), where the failure of a communication node may isolate segments of the network covering several nodes. The main goal of this study is to develop a resilience model that would allow us to analyze the effects of individual UAV failures on the team\u27s performance to improve the team\u27s resilience. The proposed solution models and simulates the UAV team using Agent-Based Modeling and Simulation. UAVs are modeled as autonomous agents, and the searched terrain as a two-dimensional M x N grid. Communication between agents permits having the exact data on the transit and occupation of all cells in real time. Such communication allows the UAV agents to estimate the best alternatives to move within the grid and know the exact number of all agents\u27 visits to the cells. Each UAV is simulated as a hobbyist, fixed-wing airplane equipped with a generic set of actuators and a generic controller. Individual UAV failures are simulated following reliability Fault Trees. Each affected UAV is disabled and eliminated from the pool of active units. After each unit failure, the system generates a new topology. It produces a set of minimum-distance trees for each node (UAV) in the grid. The new trees will thus depict the rearrangement links as required after a node failure or if changes occur in the topology due to node movement. The model should generate parameters such as the number and location of compromised nodes, performance before and after the failure, and the estimated time of restitution needed to model the team\u27s resilience. The study addresses three research goals: identifying appropriate tools for modeling UAV scenarios, developing a model for assessing UAVs team resilience that overcomes previous studies\u27 limitations, and testing the model through multiple simulations. The study fills a gap in the literature as previous studies focus on system communication disruptions (i.e., node failures) without considering UAV unit reliability. This consideration becomes critical as using small, low-cost units prone to failure becomes widespread

Intégration des algorithmes de généralisation et des patrons géométriques pour la création des objets auto-généralisants (SGO) afin d'améliorer la généralisation cartographique à la volée

Le développement technologique de ces dernières années a eu comme conséquence la démocratisation des données spatiales. Ainsi, des applications comme la cartographie en ligne et les SOLAP qui permettent d’accéder à ces données ont fait leur apparition. Malheureusement, ces applications sont très limitées du point de vue cartographique car elles ne permettent pas une personnalisation flexible des cartes demandées par l’utilisateur. Pour permettre de générer des produits plus adaptés aux besoins des utilisateurs de ces technologies, les outils de visualisation doivent permettre entre autres de générer des données à des échelles variables choisies par l'utilisateur. Pour cela, une solution serait d’utiliser la généralisation cartographique automatique afin de générer les données à différentes échelles à partir d’une base de données unique à grande échelle. Mais, compte tenu de la nature interactive de ces applications, cette généralisation doit être réalisée à la volée. Depuis plus de trois décennies, la généralisation automatique est devenue un sujet de recherche important. Malheureusement, en dépit des avancées considérables réalisées ces dernières années, les méthodes de généralisation cartographique existantes ne garantissent pas un résultat exhaustif et une performance acceptable pour une généralisation à la volée efficace. Comme, il est actuellement impossible de créer à la volée des cartes à des échelles arbitraires à partir d’une seule carte à grande échelle, les résultats de la généralisation (i.e. les cartes à plus petites échelles générées grâce à la généralisation cartographique) sont stockés dans une base de données à représentation multiple (RM) en vue d’une éventuelle utilisation. Par contre, en plus du manque de flexibilité (car les échelles sont prédéfinies), la RM introduit aussi la redondance à cause du fait que plusieurs représentations de chaque objet sont stockées dans la même base de données. Tout ceci empêche parfois les utilisateurs d’avoir des données avec un niveau d’abstraction qui correspond exactement à leurs besoins. Pour améliorer le processus de la généralisation à la volée, cette thèse propose une approche basée sur un nouveau concept appelé SGO (objet auto-généralisant: Self-Generalizing Object). Le SGO permet d’encapsuler des patrons géométriques (des formes géométriques génériques communes à plusieurs objets de la carte), des algorithmes de généralisation et des contraintes d’intégrité dans un même objet cartographique. Les SGO se basent sur un processus d’enrichissement de la base de données qui permet d’introduire les connaissances du cartographe dans les données cartographiques plutôt que de les générer à l’aide des algorithmes comme c’est typiquement le cas. Un SGO est créé pour chaque objet individuel (ex. un bâtiment) ou groupe d’objets (ex. des bâtiments alignés). Les SGO sont dotés de comportements spécifiques qui leur permettent de s'auto-généraliser, c.-à-d. de savoir comment généraliser l’objet qu’ils représentent lors d’un changement d’abstraction (ex. changement d’échelle). Comme preuve de concept, deux prototypes basés sur des technologies Open Source ont été développés lors de cette thèse. Le premier permet la création des SGO et l’enrichissement de la base de données. Le deuxième prototype basé sur la technologie multi-agent, utilise les SGO créés pour générer des données à des échelles arbitraires grâce à un processus de généralisation à la volée. Pour tester les prototypes, des données réelles de la ville de Québec à l’échelle 1 : 1000 ont été utilisées.With the technological development of these past years, geospatial data became increasingly accessible to general public. New applications such as Webmapping or SOLAP which allow visualising the data also appeared. However, the dynamic and interactive nature of these new applications requires that all operations, including generalization processes, must be carried on-the–fly. Automatic generalization has been an important research topic for more than thirty years. In spite of recent advances, it clearly appears that actual generalization methods can not reach alone the degree of automation and the response time needed by these new applications. To improve the process of on-the-fly map generalization, this thesis proposes an approach based on a new concept called SGO (Self-generalizing object). The SGO allows to encapsulate geometric patterns (generic geometric forms common to several map features), generalization algorithms and the spatial integrity constraints in the same object. This approach allows us to include additional human expertise in an efficient way at the level of individual cartographic features, which then leads to database enrichment that better supports automatic generalization. Thus, during a database enrichment process, a SGO is created and associated with a cartographic feature, or a group of features. Then, each created SGO is transformed into a software agent (SGO agent) in order to give them autonomy. SGO agents are equipped with behaviours which enable them to coordinate the generalization process. As a proof of concept, two prototypes based on Open Source technologies were developed in this thesis. The first prototype allows the creation of the SGO. The second prototype based on multi-agents technology, uses the created SGO in order to generate data on arbitrary scales thanks to an on-the-fly map generalization process. Real data of Quebec City at scale 1: 1000 were used in order to test the developed prototypes