Results 1  10
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16
Forward models: Supervised learning with a distal teacher
 Cognitive Science
, 1992
"... Internal models of the environment have an important role to play in adaptive systems in general and are of particular importance for the supervised learning paradigm. In this paper we demonstrate that certain classical problems associated with the notion of the \teacher " in supervised learnin ..."
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Cited by 295 (7 self)
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Internal models of the environment have an important role to play in adaptive systems in general and are of particular importance for the supervised learning paradigm. In this paper we demonstrate that certain classical problems associated with the notion of the \teacher " in supervised learning can be solved by judicious use of learned internal models as components of the adaptive system. In particular, we show how supervised learning algorithms can be utilized in cases in which an unknown dynamical system intervenes between actions and desired outcomes. Our approach applies to any supervised learning algorithm that is capable of learning in multilayer networks.
Image enhancement for the visually impaired
 Opt. Engineering
, 1984
"... Image enhancement as an aid for the visually impaired may improve visibility of TV programs and provide portable visual aid. This paper describes the current techniques for image enhancement and their underlying models. The limitations of the various techniques and of potential methods of implementa ..."
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Cited by 29 (21 self)
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Image enhancement as an aid for the visually impaired may improve visibility of TV programs and provide portable visual aid. This paper describes the current techniques for image enhancement and their underlying models. The limitations of the various techniques and of potential methods of implementation are highlighted. Initial work in this area was based on a linear model. The finite dynamic range available in the video display and contamination of the enhanced image by high spatial frequency noise limited the mo'del's usefulness. I propose a method to address some limitations of the original model that considers the nonlinear response of the visual system and requires enhancement of subthreshold spatial information only. This
Linear TimeFrequency Filters: Online Algorithms and Applications
, 2002
"... This chapter discusses practical discretetime methods for the timefrequency (TF) design of linear timevariant (LTV) filters. The filters are specified via a prescribed TF weight function (timevarying transfer function). We consider both explicit TF filter designs where a TF representation of the ..."
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Cited by 11 (3 self)
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This chapter discusses practical discretetime methods for the timefrequency (TF) design of linear timevariant (LTV) filters. The filters are specified via a prescribed TF weight function (timevarying transfer function). We consider both explicit TF filter designs where a TF representation of the LTV filter is matched to the specified TF weight function, and implicit TF filter designs that use an analysisweightingsynthesis procedure involving a linear TF signal representation. All filter designs allow for efficient online implementations and are thus suited to realtime applications. Our theoretical development is complemented by detailed descriptions of online algorithms, discussions of the choice of design parameters, and estimates of computational complexity and memory requirements. The performance and selected applications of the various TF filters are illustrated via numerical simulations.
Channel selection requirements for Bluetooth receivers using a simple demodulation algorithm
 12 nd proRISC workshop on Circuits, Systems and Signal Processing
, 2001
"... In our Software Defined Radio (SDR) project we combine two di#erent types of standards, Bluetooth and HiperLAN/2, on one common hardware platform. SDR system research aims at the design, implementation and deployment of flexible radio systems that are reprogrammable and reconfigurable by software. ..."
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Cited by 6 (5 self)
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In our Software Defined Radio (SDR) project we combine two di#erent types of standards, Bluetooth and HiperLAN/2, on one common hardware platform. SDR system research aims at the design, implementation and deployment of flexible radio systems that are reprogrammable and reconfigurable by software.
Bluetooth Demodulation Algorithms and Their Performance
 nd Karlsruhe Workshop on Software Radios
, 2002
"... In our Software Defined Radio SDR project we aim at combining two different types of standards, Bluetooth and HiperLAN/2 on one common hardware platform. Goal of our project is to generate knowledge about designing the front end of an SDR system (from the antenna signal to the channel bit stream) wh ..."
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Cited by 6 (5 self)
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In our Software Defined Radio SDR project we aim at combining two different types of standards, Bluetooth and HiperLAN/2 on one common hardware platform. Goal of our project is to generate knowledge about designing the front end of an SDR system (from the antenna signal to the channel bit stream) where especially an approach from both analog and digital perspective is essential.
Effects Of Source Distributions And Correlation On Fractionally Spaced Blind Constant Modulus Algorithm Equalizers
, 1995
"... Simplicial Complex: By an abstract simplicial complex with vertices in a set V , we mean a family of finite subsets of V satisfying the condition that K is hereditary, i. e. every subset of any set in K is also in K. Subcomplex Let K and L be any two abstract simplicial complexes with vertices V an ..."
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Cited by 6 (0 self)
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Simplicial Complex: By an abstract simplicial complex with vertices in a set V , we mean a family of finite subsets of V satisfying the condition that K is hereditary, i. e. every subset of any set in K is also in K. Subcomplex Let K and L be any two abstract simplicial complexes with vertices V and W respectively. If L ae K, then L is said to be a subcomplex of K. Topological Realization Let K be an arbitrarily given abstract simplicial complex. We will construct a space P = jKj called the topological realization as follows. For each finite set F 2 K, consider the simplex oe F defined in the previous section. These simplexes foe F jF 2 Kg (without the identification introduced in studying their faces) are by definition disjoint topological spaces. Form their topological sum S = S(K) = X F2K oe F : Then S is clearly a metrizable space containing every simplex oe F as an open and closed subspace. Introduce a relation ¸ in S as follows. Let f 2 oe F and g 2 oe G be any two points in ...
Specification for Digital Channel Selection Filters in a Bluetooth Capable HiperLAN/2 Receiver
 2 nd Karlsruhe Workshop on Software Radios
, 2002
"... In this paper we first briefly describe how the analog part of the channel selection function for a HiperLAN/2 receiver can be used as part of the channel selection function for a Bluetooth receiver. Thereafter we proceed to specify the overall requirements for the Bluetooth channel selection functi ..."
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Cited by 3 (3 self)
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In this paper we first briefly describe how the analog part of the channel selection function for a HiperLAN/2 receiver can be used as part of the channel selection function for a Bluetooth receiver. Thereafter we proceed to specify the overall requirements for the Bluetooth channel selection function.
Sparse Spectrum Gaussian Process Regression
"... We present a new sparse Gaussian Process (GP) model for regression. The key novel idea is to sparsify the spectral representation of the GP. This leads to a simple, practical algorithm for regression tasks. We compare the achievable tradeoffs between predictive accuracy and computational requiremen ..."
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Cited by 3 (0 self)
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We present a new sparse Gaussian Process (GP) model for regression. The key novel idea is to sparsify the spectral representation of the GP. This leads to a simple, practical algorithm for regression tasks. We compare the achievable tradeoffs between predictive accuracy and computational requirements, and show that these are typically superior to existing stateoftheart sparse approximations. We discuss both the weight space and function space representations, and note that the new construction implies priors over functions which are always stationary, and can approximate any covariance function in this class.
Sound Field Analysis along a Circle and Its Applications to HRTF Interpolation
, 2008
"... The sampling and interpolation of a sound field in two and three dimensions along a circle is discussed. The Fourier domain representation of the sound field is used, and an angular sampling theorem is developed for the sampling of the sound field along a circle. Based on these results, HRTF samplin ..."
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Cited by 2 (0 self)
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The sampling and interpolation of a sound field in two and three dimensions along a circle is discussed. The Fourier domain representation of the sound field is used, and an angular sampling theorem is developed for the sampling of the sound field along a circle. Based on these results, HRTF sampling and interpolation are discussed. This method achieves very precise interpolation in terms of mean square error. However, these results are only possible if very finely spaced HRTF measurements are available. A method is proposed to improve interpolation results when the HRTF measurements are more coarsely spaced than dictated by the angular Nyquist theorem. The proposed method interpolates the HRTFs in a subband domain. In subbands where small angular aliasing occurs, the previous method is applied. In the other subbands, interpolation is carried out in a complex temporal envelope domain to avoid aliasing. Simulations with models and measured data show that the proposed algorithm performs significantly better than previous methods in a mean square error sense.
A NonCoherent Correlation Technique and Focused Beamforming for Ultrasonic Underwater Imaging: a Comparative Analysis
, 1994
"... The purpose of this paper is to describe a noncoherent correlation technique for the formation of 3D acoustic images, mainly for underwater applications. This technique is applied to the envelope of signals received by a twodimensional array. The performances of the technique are compared with tho ..."
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The purpose of this paper is to describe a noncoherent correlation technique for the formation of 3D acoustic images, mainly for underwater applications. This technique is applied to the envelope of signals received by a twodimensional array. The performances of the technique are compared with those of the coherent technique of focused beamforming in terms of angular resolution, depth of field, beam pattern, and accuracy in range determination. Moreover, special attention is given to the modalities for an efficient implementation on a digital computer. The complete absence of grating lobes, for whatever arrangement of the transducers, and the much higher speed of the imaging process, as compared with that of beamforming in the time domain, are the two major advantages of this technique. A reduction in the speckle effect, the possibility of creating a virtual depth of field, the feasibility of using squarelaw transducers, and the implementation simplicity are additional interesting c...