1,720,976 research outputs found
Robots as cyber-physical systems: new perspectives for the design of autonomous robots
No full textToday’s control systems are made of an embedded system connected to the
system to be controlled through a feedback loop; thus the physical process
influence the computation and vice versa. The term “cyber-physical system”
defines a control system developed according to a new design methodology,
which models both the systems taking into account their reciprocal interactions.
In the current scientific literature, the design of control systems for au-
tonomous robots is a problem to be addressed separately from the application
of real-time techniques or artificial intelligence techniques on them. However,
choices made to solve one of the two problems may have consequences on the
other. Therefore, it seems that it is not sufficient to separately understand both
the problems: it is important to understand the interaction between them.
This thesis proposes an alternative approach to the design of intelligent au-
tonomous robots, derived from the cyber-physical approach to control systems,
which consists in tackling jointly both the problem of controlling the robotic
system and the problem of deploying an artificial intelligent application on it.
In the first part of the thesis various modelling abstractions are presented and
described in detail. Continuous and discrete modelling techniques for physical
and computing systems are described in chapters 2 and 3, respectively. Chapter
4 describes modelling techniques to integrate the previous models in a single
model. Chapter 5, then, introduces some modelling techniques for concurrent
computation.
The second part of the thesis is devoted to embedded and real-time systems.
In chapter 6 the most common embedded architectures are described, focusing
on parallelism and on the characteristics that make them suitable or unsuitable
for application in intelligent autonomous robotics. Chapter 7 introduces vari-
ous I/O mechanism and the interrupt paradigm, which governs the interaction
between high-level computing systems and low-level control systems. Chap-
ter 8 describes the basic of real-time operating systems, focusing mainly on
scheduling under various degree of constraints.
Finally, the third part of the thesis apply theories and methodologies intro-
duced in the first two part to the design of an intelligent autonomous robot
system to be used in the contexts of video-surveillance and ambient-assisted
living
Lachesis: a testsuite for Linux based real-time systems
Full text linkTesting is a key step in software development cycle. Error and bug fixing costs can easily exceed development costs without a full and comprehensive test on the system. First efforts to introduce real-time features in the Linux kernel are now more than ten years old. Nevertheless, no comprehensive testsuites is able to assess the functionality or the conformance to the real-time operating systems standards of the Linux kernel and of real-time nanokernels that rely on it. In this paper we propose Lachesis, an automated testsuite derived from the LTP (Linux Test Project) real-time tests. Lachesis main goals are: to provide extensive and comprehensive testing of real-time Linux features; to provide a set of functional, regression, performance and stress test, either developing or porting them from other testsuites; to design and experiment a series of build tests; to minimize development time for new tests; to make the testsuite extensible and portable. Lachesis can be used to test Linux, PREEMPT_RT, RTAI and Xenomai real-time features and performances. It provides some tests for SCHED_DEADLINE patch, too. Lachesis is now under active development: extensions to other real-time systems and more tests are planned to be added in the near future
Combining Artificial Intelligence and NetMedicine for Ambient Assisted Living: A distributed BDI-based expert system
No full textWorld population is shifting towards older ages: according to recent estimates there will be 1.5 billion people over 65 years old in 2050. Local governments, international institutions, care organizations and industry are fostering the research community to find solutions to face the unprecedented challenges raised by population ageing. A combination of Artificial Intelligence and NetMedicine could be ideal to face these challenges: they provide the means to develop an intelligent system and simultaneously to distribute it over a network, allowing the communication over the internet, if needed. Hence, the authors present a Multi-Agent Architecture for Ambient Assisted Living (AAL): it is the model for a system to manage a distributed sensor network composed by ambient and biometric sensors. The system should analyse data and pro-active ly decide to trigger alarms if anomalies are detected. The authors tested the architecture implementing a prototypical Multi-Agent System (MAS), based on Belief-Desire-Intention (BDI) paradigm: the Virtual Care
Secure Data and Voice Transmission over GSM Voice Channel: Applications for Secure Communications.
Full text linkThe GSM voice channel is the world's most widely used mobile communication network. Unfortunately these networks are affected by serious vulnerability from hardware-based attacks and communications can be easy to intercept. This paper describes a prototype implementation of a device which enables secure data and voice transmission over GSM voice channel network. The proposed system is supposed to interact with every cell phone or mobile device connected to the GSM network, differentiating itself from the best-known crypto-phone category. In the following, we will highlight the particular modulation strategy used to generate a specific wave-form that allows the receiver to correctly decipher data with a very low BER. In conclusion, this work aims to define the principles to model a secure infrastructure over a GSM network
Towards multi-agent Health Information Systems
No full textOne of the key challenges in the healthcare sector is to adapt Health Information Systems to requirements coming from changing societies. In recent years, governments and international healthcare organizations defined a series of requirements for new generation Health Information Systems: they have to preserve past investments on legacy systems, but must also integrate new technologies, include the patient among their users, and ensure that clinical information are available at all times, even in places far from where information are physically stored. This paper proposes a multi agent-oriented architecture for Health Information Systems, which uses international standards for communication and management of clinical documents. The architecture tries to effectively model a generic healthcare organization, and aims at being easily extensible and adaptable to the particularities of specific healthcare systems. The authors present two experimental scenarios to test the proposed multi-agent health information system. In the first, they show how to model a specific use case, a radiology workflow, using agents and well-known standards; in the second one the authors demonstrate how a mobile application can use the services provided by the agents to support the medical staff in an emergency situation
An Active Monitoring System for Real-Time Face-Tracking based on Mobile Sensors
Full text linkSurveillance systems frequently use fixed or semimobile cameras. However, in many cases, the use of intelligent mobile sensors is preferrable over fixed sensors, because the system configuration can be modified according to particular environmental conditions or adapted to compensate for one or more malfunctioning sensors. This paper proposes a real-time surveillance system based on a mobile sensor. Using an Android smartphone and a face-tracking algorithm, the system can move autonomously to track the human face with the longest presence in the video field. In addition, the system can be connected to a computer performing face-recognition through a wireless connection provided by the smartphone. This way the mobile sensor can track a determined human face. The paper provides some experimental results to validate system performance
Testing Linux-based real-time systems: Lachesis
No full textTesting is a key step in the software development cycle. Errors and bug fixing costs can significantly affect development costs without a full and comprehensive test on the system. Testing is even more important in real-time systems, because they are used in environments where a single failure could lead to serious damages. The first efforts to change the Linux kernel, introducing in it some real-time features, are dating back more than ten years ago. Nevertheless, up to now there's not a comprehensive test suite able to assesses the functionality and the conformance to the real-time operating systems standards for the Linux kernel and for the real-time nanokernels that rely on it. This paper discusses an ongoing work on Lachesis, an automated test suite for real-time Linux features. Lachesis's main goals are: to provide a standard and simple API to develop new tests; to provide a set of functional, regression, performance and stress test, either developing or porting them from other test suites; to design and experiment a series of build tests; to make the test suite extensible and portable. Up to now Lachesis is used to test Linux, PREEMPT RT, RTAI and Xenomai real-time features and performances. It provides some tests for SCHED DEADLINE patch, too. Lachesis is under active development: extensions to other real-time systems and more tests are planned to be added in the near futur
A Multi-Agent Expert System Simulation for Ambient Assisted Living: The Virtual Carer ExperienceAmbient Assisted Living
No full textA shift in the distribution of population towards older ages is occurring in almost every country of the world and it is becoming a major problem in Europe, Japan and USA, due to the high dependency ratio of these countries. Ambient Assisted Living (AAL) and Ambient Intelligence (AmI) are polarising the attention of the research community, trying to improve the quality of life of elderly people promoting their autonomy, self-confidence and mobility. Artificial Intelligence (AI), developing intelligent and adaptable systems, can play a considerable role in AAL and AmI to cope with the changing needs that characterize the life of people with chronic diseases. To show a possible contribution of AI in these fields, this paper introduces the multi-agent architecture of an expert system for Ambient Assisted Living: the Virtual Carer (VC). Based on the Belief-Desire-Intention (BDI) paradigm, it models the behaviours of a human caregiver. The main goal of the Virtual Carer is to help an elderly patient in his daily activities, while his health conditions are monitored, in order to ensure his security. To show the main capabilities of the system, the paper describes some simulations of the proposed agency, highlighting the architecture of the reasoning component
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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