178 research outputs found

    Design and construction of an upgraded hybrid rocket

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    Hybrid rockets are a type of chemical space propulsion that is nowadays still in an experimental phase, but that can become one of the most important propulsion technologies due to its advantages with respect to the existing ones. The present work consist on developing an upgraded hybrid rocket model which has been modified with respect to the existing one in order to obtain better performances and results. The aim of this project is to create a safer model with a safer ignition system as well as a fully redesigned gas-injection and thrust measurement system. Also, a mathematical one-dimensional model has been implemented in order to predict and study the behavior of the hybrid rocket model to achieve a better comprehension of this topic. The ultimate purpose of the project is to acquire a deep understanding concerning the space propulsion, concretely the one associated with hybrid rocket propulsion.Ingeniería Aeroespacia

    Agent organisations: from independent agents to virtual organisations and societies of agents

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    Real world applications using agent-based solutions can include many agents that needs to communicate and interact with each other in order to meet their objectives. In organisations; Agent open multi-agent systems, problems can include not only the organisation of a large number of agents, but can also be heterogeneous and of unpredictable provenance or behavior. An overview of the alternatives for dealing with these problems is presented, highlighting the way they try to solve or mitigate them. This approach allows the development of complex systems in which there are agents that show very different behaviours and that are able to adapt to unforeseen changes in the environment. This makes it possible to simulate socio-technical or natural environments and observe their possible evolution without the ethical considerations involved in experimenting in real environments.This work has been developed as part of “Virtual-Ledgers-Tecnologías DLT/Blockchain y Cripto-IOT sobre organizaciones virtuales de agentes ligeros y su aplicación en la eficiencia en el transporte de última milla”, ID SA267P18, project financed by Junta Castilla y León, Consejería de Educación, and FEDER funds. It has been partially supported by the European Regional Development Fund (ERDF) through the Interreg Spain-Portugal V-A Program (POCTEP) under grant 0631_DIGITEC_3_E (Smart growth through the specialization of the cross-border business fabric in advanced digital technologies and blockchain.)

    A hybrid agent-based classification mechanism to detect denial of service attacks

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    This paper presents the core component of a solution based on agent technology specifically adapted for the classification of SOAP messages. The messages can carry out attacks that target the applications providing Web Services. One of the most common attacks requiring novel solutions is the denial of service attack (DoS), caused for the modifications introduced in the XML of the SOAP messages. The specifications of existing security standards do not focus on this type of attack. This article presents an advanced mechanism of classification designed in two phases incorporated within a CBR-BDI Agent type. This mechanism classifies the incoming SOAP message and blocks the malicious SOAP messages. Its main feature involves the use of decision trees, fuzzy logic rules and neural networks for filtering attacks. These techniques provide a mechanism of classification with the self-adaption ability to the changes that occur in the patterns of attack. A prototype was developed and the results obtained are presented in this study.This paper presents the core component of a solution based on agent technology specifically adapted for the classification of SOAP messages. The messages can carry out attacks that target the applications providing Web Services. One of the most common attacks requiring novel solutions is the denial of service attack (DoS), caused for the modifications introduced in the XML of the SOAP messages. The specifications of existing security standards do not focus on this type of attack. This article presents an advanced mechanism of classification designed in two phases incorporated within a CBR-BDI Agent type. This mechanism classifies the incoming SOAP message and blocks the malicious SOAP messages. Its main feature involves the use of decision trees, fuzzy logic rules and neural networks for filtering attacks. These techniques provide a mechanism of classification with the self-adaption ability to the changes that occur in the patterns of attack. A prototype was developed and the results obtained are presented in this study

    Dynamic Monitoring in PANGEA Platform Using Event-Tracing Mechanisms

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    The use of distributed multi-agent systems (MAS) have increased in recent years, with the growing potential to handle large volumes of data and coordinate the operations of many organizations. In these systems, each agent independently handles a set of specialized tasks and cooperates to achieve the goals of the system and a high degree of flexibility. Multi-agent systems have become the most effective and widely used form of developing this type of application in which communication among various devices must be both reliable and efficient. One of the problems related to distribute computing is message passing, which is related to the interaction and coordination among intelligent agents. Consequently, a multi-agent architecture must necessarily provide a robust communication platform and control mechanisms. This paper presents the integration of an event-tracing model in an agent platform called PANGEA. Adding this new capability, the platform allows improving the monitoring and analysis of the information that agents can send/receive in order to fulfil their goals more efficiently

    Self-organizing multi-agent system for management and planning surveillance routes

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    This paper presents the THOMAS architecture, specially designed to model open multi-agent systems, and its application in the development of a multi-agent system for managing and planning surveillance routes for security personnel. THOMAS uses agents with reasoning and planning capabilities. These agents can perform a dynamic self-organization when they detect changes in the environment. THOMAS is appropriate for developing systems in highly dynamic environments similar to the one presented in this study, as demonstrated by the results obtained after having applied the system to a case study.Web of Science3151100108

    Self-Organizing Multi-Agent System for Management and Planning Surveillance Routes

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    This paper presents the THOMAS architecture, specially designed to model open multi-agent systems, and its application in the development of a multi-agent system for managing and planning surveillance routes for security personnel. THOMAS uses agents with reasoning and planning capabilities. These agents can perform a dynamic self-organization when they detect changes in the environment. THOMAS is appropriate for developing systems in highly dynamic environments similar to the one presented in this study, as demonstrated by the results obtained after having applied the system to a case study

    Sensoring a Generative System to Create User-Controlled Melodies

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    [EN] The automatic generation of music is an emergent field of research that has attracted the attention of countless researchers. As a result, there is a broad spectrum of state of the art research in this field. Many systems have been designed to facilitate collaboration between humans and machines in the generation of valuable music. This research proposes an intelligent system that generates melodies under the supervision of a user, who guides the process through a mechanical device. The mechanical device is able to capture the movements of the user and translate them into a melody. The system is based on a Case-Based Reasoning (CBR) architecture, enabling it to learn from previous compositions and to improve its performance over time. The user uses a device that allows them to adapt the composition to their preferences by adjusting the pace of a melody to a specific context or generating more serious or acute notes. Additionally, the device can automatically resist some of the user’s movements, this way the user learns how they can create a good melody. Several experiments were conducted to analyze the quality of the system and the melodies it generates. According to the users’ validation, the proposed system can generate music that follows a concrete style. Most of them also believed that the partial control of the device was essential for the quality of the generated music

    Intelligent Dolls and robots for the treatment of elderly people with dementia

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    Doll and robot are effective and beneficial non-pharmacological therapies applied in different clinical settings. Doll therapy (DT), principally based in Bowlby's attachment theory, uses an empathy or lifelike baby doll to conduct caring behaviors of it. Robot therapies (RT) use care robots with a friendly attitude and appearance that create emotions and movements that lead to different verbal, motor and emotional reactions. Both DT and RT are person-centred therapies that aim to improve wellbeing of people that suffer from different neurological, psychological and mental health disorders, such as Alzheimer's Disease, autism spectrum disorder, stress or depression, by providing a realistic experience. In this paper, the characteristics of both therapies, their benefits and the possibilities of innovation in the therapeutic field are presented

    OSM: A Multi-Agent System for Modeling and Monitoring the Evolution of Oil Slicks in Open Oceans

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    A multi-agent based prediction-system is presented in which the aim is to forecast the presence of oil slicks in a certain area of the open sea after an oil spill. In this case, the multi-agent architecture incorporates a prediction-system based on the CBR methodology, implemented in a series of interactive services, for modeling and monitoring the ocean water masses. The system’s nucleus is formed by a series of deliberative agents acting as controllers and administrators for all the implemented services. The implemented services are accessible in a distributed way, and can be accessed even from mobile devices. The proposed system uses information such as sea salinity, sea temperature, wind, currents, pressure, number and area of the slicks, etc. obtained from various satellites. The system has been trained using data obtained after the Prestige accident. The Oil Spill Multi-Agent System (OSM) has been able to accurately predict the presence of oil slicks in the north-west of the Galician coast using historical data

    Intelligent Guidance and Suggestions Using Case-Based Planning

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    This paper presents a multiagent system that provides guidance on leisure facilities and suggestions for shopping in malls. This paper presents a deliberative agent which incorporates a case based planner that provides suggestions in execution time. This agent is described together with its guidance and suggestion mechanism. The multiagent system has been tested, and the results obtained are presented in this paper
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