Sensor fusion by neural networks using spatially represented information

Sektion Neurophysiologie, Universität Ulm, Germany.
Biological Cybernetics (Impact Factor: 1.93). 12/2001; 85(5):371-85. DOI: 10.1007/s004220100271
Source: PubMed

ABSTRACT A neural network model based on a lateral-inhibition-type feedback layer is analyzed with regard to its capabilities to fuse signals from two different sensors reporting the same event ("multisensory convergence"). The model consists of two processing stages. The input stage holds spatial representations of the sensor signals and transmits them to the second stage where they are fused. If the input signals differ, the model exhibits two different processing modes: with small differences it produces a weighted average of the input signals, whereas with large differences it enters a decision mode where one of the two signals is suppressed. The dynamics of the network can be described by a series of two first-order low-pass filters, whose bandwidth depends nonlinearly on the level of concordance of the input signals. The network reduces sensor noise by means of both its averaging and filtering properties. Hence noise suppression, too, depends on the level of concordance of the inputs. When the network's neurons have internal noise, sensor noise suppression is reduced but still effective as long as the input signals do not differ strongly. The possibility of extending the scheme to three and more inputs is discussed.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Breast cancer is a common and dreadful disease in women. The surface temperature and the vascularization pattern of the breast could indicate breast diseases. Establishing the surface isotherm pattern of the breast and the normal range of cyclic variations of temperature distribution can assist in identifying the abnormal infrared images of diseased breasts. This paper investigates the cyclic variation of temperature and vascularization of the normal breast thermograms under a controlled environment. More than 50 Asian women, were examined and some of them have been examined continuously for two month. All together, not less than 800 thermograms were obtained. Before these thermograms can be analysed objectively via a computer algorithm, they must be digitized and segmented. The authors present a method to segment thermograms and extract the useful region from the background. After the image processing, these thermograms can be analysed and then the best time to perform an examination can be chosen. All these results are important for establishing a data bank of normal breast thermography, to choose the best time for an examination and as a systematic methodology for evaluating and analysing the abnormal breast thermography in the future.
    Journal of Medical Engineering & Technology 25(1):12-6.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The “applied” nature distinguishes applied sciences from theoretical sciences. To emphasize this distinction, we begin with a general, meta-level overview of the scientific endeavor. We introduce the notion of knowledge spectrum and four interconnected modalities of knowledge. In addition to the traditional differentiation between implicit and explicit knowledge, we outline the concepts of general and individual knowledge. We connect general knowledge with the “frame problem,” a fundamental issue of artificial intelligence, and individual knowledge with another important paradigm of artificial intelligence, case-based reasoning, a method of individual knowledge processing that aims at solving new problems based on the solutions to similar past problems.
    07/2005: pages 59-59;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper discusses the integration of a geographical in- formation system (GIS) with a simulation model of the sensors (active and passive) used as components of a de- tection system on US Navy ships. The simulation model is a tool developed to improve threat recognition, undersea tactical awareness, countermeasure emissions, and counter- weapon fire control that enables surface ships to survive a salvo of torpedo attacks. The model, was implemented (2005-2006) in Java using AnyLogic™ (by XJ Technolo- gies). A commercial GIS application provides data visuali- zation, query, analysis, and integration capabilities along with the ability to create and edit geographic data. The simulation model runs and seamlessly gets geographical information from ArcGIS (by ESRI corporation) in order to make decisions such as avoiding a ship going aground. Statistics and animations are controlled by the simulation software, while the maps and the movements of the envi- ronment object above of the map is handled by ArcGIS.
    Proceedings of the Winter Simulation Conference, WSC 2007, Washington, DC, USA, December 9-12, 2007; 01/2007