2,733 research outputs found
Neural Networks: Implementations and Applications
Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering area
Hydroelectric power plant management relying on neural networks and expert system integration
The use of Neural Networks (NN) is a novel approach that can help in taking decisions when integrated in a more general system, in particular with expert systems. In this paper, an architecture for the management of hydroelectric power plants is introduced. This relies on monitoring a large number of signals, representing the technical parameters of the real plant. The general architecture is composed of an Expert System and two NN modules: Acoustic Prediction (NNAP) and Predictive Maintenance (NNPM). The NNAP is based on Kohonen Learning Vector Quantization (LVQ) Networks in order to distinguish the sounds emitted by electricity-generating machine groups. The NNPM uses an ART-MAP to identify different situations from the plant state variables, in order to prevent future malfunctions. In addition, a special process to generate a complete training set has been designed for the ART-MAP module. This process has been developed to deal with the absence of data about abnormal plant situations, and is based on neural nets trained with the backpropagation algorithm.Publicad
Neural Network Applications
Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering area
Industrial process monitoring by means of recurrent neural networks and Self Organizing Maps
Industrial manufacturing plants often suffer from reliability problems during their day-to-day operations which
have the potential for causing a great impact on the effectiveness and performance of the overall process and the
sub-processes involved. Time-series forecasting of critical industrial signals presents itself as a way to reduce this
impact by extracting knowledge regarding the internal dynamics of the process and advice any process deviations
before it affects the productive process. In this paper, a novel industrial condition monitoring approach based on the
combination of Self Organizing Maps for operating point codification and Recurrent Neural Networks for critical signal
modeling is proposed. The combination of both methods presents a strong synergy, the information of the operating
condition given by the interpretation of the maps helps the model to improve generalization, one of the drawbacks of
recurrent networks, while assuring high accuracy and precision rates. Finally, the complete methodology, in terms of
performance and effectiveness is validated experimentally with real data from a copper rod industrial plant.Postprint (published version
A Real-Time Novelty Detector for a Mobile Robot
Recognising new or unusual features of an environment is an ability which is
potentially very useful to a robot. This paper demonstrates an algorithm which
achieves this task by learning an internal representation of `normality' from
sonar scans taken as a robot explores the environment. This model of the
environment is used to evaluate the novelty of each sonar scan presented to it
with relation to the model. Stimuli which have not been seen before, and
therefore have more novelty, are highlighted by the filter. The filter has the
ability to forget about features which have been learned, so that stimuli which
are seen only rarely recover their response over time. A number of robot
experiments are presented which demonstrate the operation of the filter.Comment: 8 pages, 6 figures. In Proceedings of EUREL European Advanced
Robotics Systems Masterclass and Conference, 200
AI and OR in management of operations: history and trends
The last decade has seen a considerable growth in the use of Artificial Intelligence (AI) for operations management with the aim of finding solutions to problems that are increasing in complexity and scale. This paper begins by setting the context for the survey through a historical perspective of OR and AI. An extensive survey of applications of AI techniques for operations management, covering a total of over 1200 papers published from 1995 to 2004 is then presented. The survey utilizes Elsevier's ScienceDirect database as a source. Hence, the survey may not cover all the relevant journals but includes a sufficiently wide range of publications to make it representative of the research in the field. The papers are categorized into four areas of operations management: (a) design, (b) scheduling, (c) process planning and control and (d) quality, maintenance and fault diagnosis. Each of the four areas is categorized in terms of the AI techniques used: genetic algorithms, case-based reasoning, knowledge-based systems, fuzzy logic and hybrid techniques. The trends over the last decade are identified, discussed with respect to expected trends and directions for future work suggested
Fault prediction in aircraft engines using Self-Organizing Maps
Aircraft engines are designed to be used during several tens of years. Their
maintenance is a challenging and costly task, for obvious security reasons. The
goal is to ensure a proper operation of the engines, in all conditions, with a
zero probability of failure, while taking into account aging. The fact that the
same engine is sometimes used on several aircrafts has to be taken into account
too. The maintenance can be improved if an efficient procedure for the
prediction of failures is implemented. The primary source of information on the
health of the engines comes from measurement during flights. Several variables
such as the core speed, the oil pressure and quantity, the fan speed, etc. are
measured, together with environmental variables such as the outside
temperature, altitude, aircraft speed, etc. In this paper, we describe the
design of a procedure aiming at visualizing successive data measured on
aircraft engines. The data are multi-dimensional measurements on the engines,
which are projected on a self-organizing map in order to allow us to follow the
trajectories of these data over time. The trajectories consist in a succession
of points on the map, each of them corresponding to the two-dimensional
projection of the multi-dimensional vector of engine measurements. Analyzing
the trajectories aims at visualizing any deviation from a normal behavior,
making it possible to anticipate an operation failure.Comment: Communication pr\'esent\'ee au 7th International Workshop WSOM 09, St
Augustine, Floride, USA, June 200
Cutting tool condition monitoring of the turning process using artificial intelligence
This thesis relates to the application of Artificial Intelligence to tool wear monitoring. The
main objective is to develop an intelligent condition monitoring system able to detect when a
cutting tool is worn out. To accomplish this objective it is proposed to use a combined Expert
System and Neural Network able to process data coming from external sensors and combine
this with information from the knowledge base and thereafter estimate the wear state of the
tool.
The novelty of this work is mainly associatedw ith the configurationo f the proposeds ystem.W ith
the combination of sensor-baseidn formation and inferencer ules, the result is an on-line system
that can learn from experience and can update the knowledge base pertaining to information
associated with different cutting conditions. Two neural networks resolve the problem of
interpreting the complex sensor inputs while the Expert System, keeping track of previous
successe, stimatesw hich of the two neuraln etworks is more reliable. Also, mis-classificationsa re
filtered out through the use of a rough but approximate estimator, the Taylor's tool life equation.
In this study an on-line tool wear monitoring system for turning processesh as been developed
which can reliably estimate the tool wear under common workshop conditions. The system's
modular structurem akesi t easyt o updatea s requiredb y different machinesa nd/or processesT. he
use of Taylor's tool life equation, although weak as a tool life estimator, proved to be crucial in
achieving higher performance levels. The application of the Self Organizing Map to tool wear
monitoring is, in itself, new and proved to be slightly more reliable then the Adaptive Resonance
Theory neural network
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