[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

A scheme is developed for classifying the types of motion perceived by a humanlike robot. It is assumed that the robot receives visual images of the scene using a perspective system model. Equations, theorems, concepts, clues, etc., relating the objects, their positions, and their motion to their images on the focal plane are presented. >

http://ieeexplore.ieee.org/iel2/815/3148/00100651.pdf

Robot vision

/pdf/remote-sensing-of-the-environment-4yfxjaaswe.pdf

Remote sensing of the environment

This paper provides a comprehensive review of the domain of physical layer security in multiuser wireless networks. The essential premise of physical layer security is to enable the exchange of confidential messages over a wireless medium in the presence of unauthorized eavesdroppers, without relying on higher-layer encryption. This can be achieved primarily in two ways: without the need for a secret key by intelligently designing transmit coding strategies, or by exploiting the wireless communication medium to develop secret keys over public channels. The survey begins with an overview of the foundations dating back to the pioneering work of Shannon and Wyner on information-theoretic security. We then describe the evolution of secure transmission strategies from point-to-point channels to multiple-antenna systems, followed by generalizations to multiuser broadcast, multiple-access, interference, and relay networks. Secret-key generation and establishment protocols based on physical layer mechanisms are subsequently covered. Approaches for secrecy based on channel coding design are then examined, along with a description of inter-disciplinary approaches based on game theory and stochastic geometry. The associated problem of physical layer message authentication is also briefly introduced. The survey concludes with observations on potential research directions in this area.

/pdf/principles-of-physical-layer-security-in-multiuser-wireless-3w4jvwpgy4.pdf

Principles of Physical Layer Security in Multiuser Wireless Networks: A Survey

In this paper, we propose a unified framework to generate a pleasant and high-quality street-view panorama by stitching multiple panoramic images captured from the cameras mounted on the mobile platform. Our proposed framework is comprised of four major steps: image warping, color correction, optimal seam line detection and image blending. Since the input images are captured without a precisely common projection center from the scenes with the depth differences with respect to the cameras to different extents, such images cannot be precisely aligned in geometry. Therefore, an efficient image warping method based on the dense optical flow field is proposed to greatly suppress the influence of large geometric misalignment at first. Then, to lessen the influence of photometric inconsistencies caused by the illumination variations and different exposure settings, we propose an efficient color correction algorithm via matching extreme points of histograms to greatly decrease color differences between warped images. After that, the optimal seam lines between adjacent input images are detected via the graph cut energy minimization framework. At last, the Laplacian pyramid blending algorithm is applied to further eliminate the stitching artifacts along the optimal seam lines. Experimental results on a large set of challenging street-view panoramic images captured form the real world illustrate that the proposed system is capable of creating high-quality panoramas.

A Unified Framework for Street-View Panorama Stitching.

A novel unsupervised sparse component extraction algorithm for diagnosing micro defects in thermography imaging system is presented The approach is optimized under Variational Bayesian framework, which is fully automated and does not require manual selection of the parameters in the solution An internal sub sparse grouping mechanism and adaptive fine-tuning have been built into the proposed algorithm to control the sparsity The proposed method is used to automatically detect the micro defects on metals Other contending defect feature extraction and sparse pattern extraction methods are employed for comparison The algorithm has been shown to improve the detection precision of both artificial and natural cracks

Variational Bayes Sub-Group Adaptive Sparse Component Extraction for Diagnostic Imaging System

The early monitoring of downhole overflow can be effectively realized by the downhole annular electromagnetic flow detection system. In order to improve the accuracy of the electromagnetic measurement system of downhole annular flow, it is important to optimize the excitation system and electrodes of this system. This research focuses on the optimization of the electrodes for the electromagnetic measurement system of downhole annular flow, whose excitation system has been optimized. First, the basic principle of electromagnetic measurement of downhole annular flow is analyzed. Then, the influence of different positions of the four-point electrodes on the virtual current distributions is analyzed, and the optimum electrode positions and distributions are introduced. On this basis, the influence of shape and size of the large electrode on virtual current density distribution is analyzed. Based on the theoretical study of the influence of electrode on virtual current density distribution, taking hemispherical electrodes and arc electrodes as examples, this paper optimizes hemispherical electrodes and arc electrodes with different shapes and sizes by using finite element simulation method, and proposes three indexes to evaluate the annular virtual current density distributions when the electrodes of different shapes are used. The optimum parameters of shapes and sizes of the hemisphere electrodes and arc electrodes under specific structures of the downhole annular electromagnetic flow measurement system are obtained. This research has great significance for the optimization of electrodes in the downhole annular electromagnetic flow measurement system, and can also be used as reference for the electrode optimization of the traditional electromagnetic flowmeter.

/pdf/electrodes-optimization-of-an-annular-flow-electromagnetic-4of8xxjork.pdf

Electrodes Optimization of an Annular Flow Electromagnetic Measurement System for Drilling Engineering

Traditionally, Reed-Solomon (RS) codes have been employed in magnetic data storage devices due to their effectiveness in correcting random errors and burst errors caused by thermal asperities and inter-symbol interference (ISI). However, as storage densities increase the effect of ISI becomes more severe and much longer RS codes are needed, but this requires significantly increasing the size of the finite field. A possible replacement for RS codes are the one-point Hermitian codes, which are a class of algebraic-geometric (AG) code that have larger block sizes and minimum Hamming distances over the same finite field. In this paper, we present a novel iterative soft detection-decoding algorithm for interleaved Hermitian codes. The soft decoding employs a joint adaptive belief propagation (ABP) algorithm and Koetter-Vardy (KV) list decoding algorithm. It is combined with a maximum a posteriori (MAP) partial response (PR) equalizer and likelihoods from the output of the KV or the ABP algorithm are fed back to the equalizer. The proposed scheme's iterative detection-decoding behavior will be analyzed by utilizing the Extrinsic Information Transfer (ExIT) chart. Our simulation results demonstrate the performance gains achieved by iterations and Hermitian codes' performance advantage over RS codes.

/pdf/iterative-detection-decoding-of-interleaved-hermitian-codes-4mldu6xnkd.pdf

Gui Yun Tian

Papers

Variational Bayes Sub-Group Adaptive Sparse Component Extraction for Diagnostic Imaging System

Electrodes Optimization of an Annular Flow Electromagnetic Measurement System for Drilling Engineering

Iterative Detection-Decoding of Interleaved Hermitian Codes for High Density Storage Devices

Study on a new electromagnetic flowmeter based on three-value trapezoidal wave excitation

Extracting information of ESPI fringes based on fringe center method