73 research outputs found
Autonomous agents for multi-function radar resource management
The multifunction radar, aided by advances in electronically steered phased array technology, is capable
of supporting numerous, differing and potentially conflicting tasks. However, the full potential of the
radar system is only realised through its ability to automatically manage and configure the finite resource
it has available. This thesis details the novel application of agent systems to this multifunction radar
resource management problem. Agent systems are computational societies where the synergy of local
interactions between agents produces emergent, global desirable behaviour.
In this thesis the measures and models which can be used to allocate radar resource is explored; this
choice of objective function is crucial as it determines which attribute is allocated resource and consequently
constitutes a description of the problem to be solved. A variety of task specific and information
theoretic measures are derived and compared. It is shown that by utilising as wide a variety of measures
and models as possible the radarās multifunction capability is enhanced.
An agent based radar resource manager is developed using the JADE Framework which is used
to apply the sequential first price auction and continuous double auctions to the multifunction radar
resource management problem. The application of the sequential first price auction leads to the development
of the Sequential First Price Auction Resource Management algorithm from which numerous
novel conclusions on radar resource management algorithm design are drawn. The application of the
continuous double auction leads to the development of the Continuous Double Auction Parameter Selection
(CDAPS) algorithm. The CDAPS algorithm improves the current state of the art by producing
an improved allocation with low computational burden. The algorithm is shown to give worthwhile
improvements in task performance over a conventional rule based approach for the tracking and surveillance
functions as well as exhibiting graceful degradation and adaptation to a dynamic environment
Safetyāoriented discrete event model for airport AāSMGCS reliability assessment
A detailed analysis of State of the Art Technologies and Procedures into Airport Advanced-Surface Movement Guidance and Control Systems has been provided in this thesis, together with the review ofStatistical Monte Carlo Analysis, Reliability Assessment and Petri Nets theories.
This practical and theoretical background has lead the author to the conclusion that there is a lack of linkage in between these fields. At the same of time the rapid increasing of Air Traffic all over the world, has brought in evidence the urgent need of practical instruments able to identify and quantify the risks connected with Aircraft operations on the ground, since the Airport has shown to be the actual ābottle neckā of the entire Air Transport System.
Therefore, the only winning approach to such a critical matter has to be multi-disciplinary, sewing together apparently different subjects, coming from the most disparate areas of interest and
trying to fulfil the gap.
The result of this thesis work has come to a start towards the end, when a Timed Coloured Petri Net (TCPN) model of a āsampleā Airport A-SMGCS has been developed, that is capable of taking into account different orders of questions arisen during these recent years and tries to give them some good answers.
The A-SMGCS Airport model is, in the end, a parametric tool relying on Discrete Event System theory, able to perform a Reliability Analysis of the system itself, that:
ā¢ uses a Monte Carlo Analysis applied to a Timed Coloured Petri Net, whose purpose is to evaluate the Safety Level of Surface Movements along an Airport
ā¢ lets the user to analyse the impact of Procedures and Reliability Indexes of Systems such as Surface Movement Radars, Automatic Dependent Surveillance-Broadcast, Airport Lighting Systems, Microwave Sensors, and so onā¦ onto the Safety Level of Airport Aircraft Transport System
ā¢ not only is a valid instrument in the Design Phase, but it is useful also into the Certifying Activities an in monitoring the Safety Level of the above mentioned System with respect to changes to Technologies and different Procedures.This TCPN model has been verified against qualitative engineering expectations by using simulation experiments and occupancy time schedules generated a priori.
Simulation times are good, and since the model has been written into Simulink/Stateflow programming language, it can be compiled to run real-time in C language (Real-time workshop and
Stateflow Coder), thus relying on portable code, able to run virtually on any platform, giving even better performances in terms of execution time.
One of the most interesting applications of this work is the estimate, for an Airport, of the kind of A-SMGCS level of implementation needed (Technical/Economical convenience evaluation). As a matter of fact, starting from the Traffic Volume and choosing the kind of Ground Equipment to be installed, one can make predictions about the Safety Level of the System: if the value is compliant with the TLS required by ICAO, the A-SMGCS level of Implementation is sufficiently adequate. Nevertheless, even if the Level of Safety has been satisfied, some delays due to reduced or simplified performances (even if Safety is compliant) of some of the equipment (e.g. with reference to False Alarm Rates) can lead to previously unexpected economical consequences, thus requiring more accurate systems to be installed, in order to meet also Airport economical constraints.
Work in progress includes the analysis of the effect of weather conditions and re-sequencing of a given schedule. The effect of re-sequencing a given schedule is not yet enough realistic since the model does not apply inter arrival and departure separations. However, the model might show some effect on different sequences based on runway occupancy times. A further developed model containing wake turbulence separation conditions would be more sensitive for this case.
Hence, further work will be directed towards:
ā¢ The development of On-Line Re-Scheduling based on the available actual runway/taxiway configuration and weather conditions.
ā¢ The Engineering Safety Assessment of some small Italian Airport A-SMGCSs (Model validation with real data).
ā¢ The application of Stochastic Differential Equations systems in order to evaluate the collision risk on the ground inside the Place alone on the Petri Net, in the event of a Short Term Conflict Alert (STCA), by adopting Reich Collision Risk Model.
ā¢ Optimal Air Traffic Control Algorithms Synthesis (Adaptive look-ahead Optimization), by Dynamically Timed Coloured Petri Nets, together with the implementation of Error-Recovery Strategies and Diagnosis Functions
Management: A bibliography for NASA managers
This bibliography lists 731 reports, articles and other documents introduced into the NASA Scientific and Technical Information System in 1990. Items are selected and grouped according to their usefulness to the manager as manager. Citations are grouped into ten subject categories: human factors and personnel issues; management theory and techniques; industrial management and manufacturing; robotics and expert systems; computers and information management; research and development; economics, costs and markets; logistics and operations management; reliability and quality control; and legality, legislation, and policy
First Annual Workshop on Space Operations Automation and Robotics (SOAR 87)
Several topics relative to automation and robotics technology are discussed. Automation of checkout, ground support, and logistics; automated software development; man-machine interfaces; neural networks; systems engineering and distributed/parallel processing architectures; and artificial intelligence/expert systems are among the topics covered
Fourth Annual Workshop on Space Operations Applications and Research (SOAR 90)
The proceedings of the SOAR workshop are presented. The technical areas included are as follows: Automation and Robotics; Environmental Interactions; Human Factors; Intelligent Systems; and Life Sciences. NASA and Air Force programmatic overviews and panel sessions were also held in each technical area
Safety and Reliability - Safe Societies in a Changing World
The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management
- mathematical methods in reliability and safety
- risk assessment
- risk management
- system reliability
- uncertainty analysis
- digitalization and big data
- prognostics and system health management
- occupational safety
- accident and incident modeling
- maintenance modeling and applications
- simulation for safety and reliability analysis
- dynamic risk and barrier management
- organizational factors and safety culture
- human factors and human reliability
- resilience engineering
- structural reliability
- natural hazards
- security
- economic analysis in risk managemen
Volume II Acquisition Research Creating Synergy for Informed Change, Thursday 19th Annual Acquisition Research Proceedings
ProceedingsApproved for public release; distribution is unlimited
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