The Experts below are selected from a list of 408435 Experts worldwide ranked by ideXlab platform

Pierre Moulin - One of the best experts on this subject based on the ideXlab platform.

  • The role of information theory in watermarking and its application to image watermarking
    Signal Processing, 2001
    Co-Authors: Pierre Moulin
    Abstract:

    This paper reviews the role of information theory in characterizing the fundamental limits of watermarking systems and in guiding the development of optimal watermark embedding algorithms and optimal attacks. Watermarking can be viewed as a Communication Problem with side information (in the form of the host signal and/or a cryptographic key) available at the encoder and the decoder. The Problem is mathematically defined by distortion constraints, by statistical models for the host signal, and by the information available in the game between the information hider, the attacker, and the decoder. In particular, information theory explains why the performance of watermark decoders that do not have access to the host signal may surprisingly be as good as the performance of decoders that know the host signal. The theory is illustrated with several examples, including an application to image watermarking. Capacity expressions are derived under a parallel-Gaussian model for the host-image source. Sparsity is the single most important property of the source that determines capacity.

Arunita Jaekel - One of the best experts on this subject based on the ideXlab platform.

  • congestion control in v2v safety Communication Problem analysis approaches
    Electronics, 2019
    Co-Authors: Xiaofeng Liu, Arunita Jaekel
    Abstract:

    The emergence of Vehicular Ad Hoc Networks (VANETs) is expected to be an important step toward achieving safety and efficiency in intelligent transportation systems (ITS). One important requirement of safety applications is that vehicles are able to communicate with neighboring vehicles, with very low latency and packet loss. The high mobility, unreliable channel quality and high message rates make this a challenging Problem for VANETs. There have been significant research activities in recent years in the development of congestion control algorithms that ensure reliable delivery of safety messages in vehicle-to-vehicle (V2V) Communication. In this paper, we present a comprehensive survey of congestion control approaches for VANET. We identify the relevant parameters and performance metrics that can be used to evaluate these approaches and analyze each approach based a number of factors such as the type of traffic, whether it is proactive or reactive, and the mechanism for controlling congestion. We conclude this paper with some additional considerations for designing V2V Communication protocols and interesting and open research Problems and directions for future work.

Aditya Ramamoorthy - One of the best experts on this subject based on the ideXlab platform.

  • sum networks from incidence structures construction and capacity analysis
    IEEE Transactions on Information Theory, 2018
    Co-Authors: Ardhendu Tripathy, Aditya Ramamoorthy
    Abstract:

    A sum-network is an instance of a function computation Problem over a directed acyclic network, in which each terminal node wants to compute the sum over a finite field of the information observed at all the source nodes. Many characteristics of the well-studied multiple unicast network Communication Problem also hold for sum-networks, due to a known reduction between the two Problems. In this paper, we describe an algorithm to construct families of sum-network instances using incidence structures. The computation capacity of several of these sum-network families is evaluated. Unlike the coding capacity of a multiple unicast Problem, the computation capacity of sum-networks depends on the characteristic of the finite field over which the sum is computed. This dependence is very strong; we show examples of sum-networks that have a rate-1 solution over one characteristic but a rate close to zero over a different characteristic. In addition, a sum-network can have arbitrarily different computation capacities for different alphabets.

  • capacity of sum networks for different message alphabets
    arXiv: Information Theory, 2015
    Co-Authors: Ardhendu Tripathy, Aditya Ramamoorthy
    Abstract:

    A sum-network is a directed acyclic network in which all terminal nodes demand the `sum' of the independent information observed at the source nodes. Many characteristics of the well-studied multiple-unicast network Communication Problem also hold for sum-networks due to a known reduction between instances of these two Problems. Our main result is that unlike a multiple unicast network, the coding capacity of a sum-network is dependent on the message alphabet. We demonstrate this using a construction procedure and show that the choice of a message alphabet can reduce the coding capacity of a sum-network from $1$ to close to $0$.

Benjamin Schrauwen - One of the best experts on this subject based on the ideXlab platform.

  • sign language recognition using convolutional neural networks
    European Conference on Computer Vision, 2014
    Co-Authors: Lionel Pigou, Sander Dieleman, Pieterjan Kindermans, Benjamin Schrauwen
    Abstract:

    There is an undeniable Communication Problem between the Deaf community and the hearing majority. Innovations in automatic sign language recognition try to tear down this Communication barrier. Our contribution considers a recognition system using the Microsoft Kinect, convolutional neural networks (CNNs) and GPU acceleration. Instead of constructing complex handcrafted features, CNNs are able to automate the process of feature construction. We are able to recognize 20 Italian gestures with high accuracy. The predictive model is able to generalize on users and surroundings not occurring during training with a cross-validation accuracy of 91.7%. Our model achieves a mean Jaccard Index of 0.789 in the ChaLearn 2014 Looking at People gesture spotting competition.

Debra J. Hanson - One of the best experts on this subject based on the ideXlab platform.

  • The Perspectives of Fieldwork Educators Regarding Level II Fieldwork Students
    Occupational Therapy in Health Care, 2011
    Co-Authors: Debra J. Hanson
    Abstract:

    ABSTRACTTen occupational therapists employed in pediatric and adult rehabilitation settings participated in focus groups to discuss their perceptions of the benefits and drawbacks in working with occupational therapy students. Participants identified professional values, opportunities for continued professional development, recruitment of future employees, and pride in learning experiences available as incentives for working with students. Fieldwork educators who had supervised students lacking foundational Communication, Problem-solving, and clinical skills were cautious about accepting future Level II students. Time constraints and lack of preparation for the educator role were perceived as barriers to working with students. Fieldwork educators expected the academic institution to provide efficient support, including training for the educator role, information regarding the expectations of the academic program, and ongoing Communication over the fieldwork experience. Strategies for strengthening the tie...