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Multimedia streaming service providers such as YouTube often need to design caching strategy based on predicted future media content propagation pattern. It is commonly observed that social network behavior tends to have great correlation with the content propagation pattern. In this paper, we propose an Advanced Independent Cascade Model (AICM) which is an extension of the existing ICM method to...
The paper focuses on 3D structure and motion factorization from uncalibrated image sequences. An alternative weighted factorization algorithm is proposed to handle noisy image measurement. The novelty and main contributions of the paper are as follows: (i) A simple while accurate quasi-perspective projection model is adopted for structure and motion factorization; (ii) feature uncertainties are estimated...
Measurement of camera response function (CRF) has become an important technique in the field of computer graphics and radiance measurement. It can be used to achieve accurate modeling and high dynamic range imaging. A method was developed in this paper by using a polariscope to provide accurate radiance for direct measurement of the CRF. The experimental results show that the accuracy of the estimated...
High Efficiency Video Coding (HEVC), a successor to H.264, is the next generation video compression standard. To enhance the coding efficiency of video frames, 35 intra prediction modes adopted in Prediction Unit (PU) from 4×4 to 64×64 of HEVC. However, the improvement is based on the cost of rapid increased complexity performance loss. This paper proposed a Pixel Gradient Statistics (PGS) and Mode...
The sufficiency principle is the guiding principle for data reduction in statistical inference. There has been recent effort in developing the sufficiency principle for decentralized inference with a particular emphasis on the relationship between global sufficiency and local sufficiency. This paper studies the sufficiency based data reduction in tandem fusion systems when quantization is needed....
Inverse Synthetic Aperture Radar (ISAR) Imaging with Low Signal to Noise Ratio (SNR) is one of difficulties in radar target detection. A new technique for ISAR motion compensation with low SNR is presented. For the range alignment, the cross-correlation method based on the exponential weight accumulative gliding window is applied to achieve the coarse range alignment. The precise range alignment within...
Based on the analysis of range-azimuth coupling in two dimensional frequency domain, a modified RD algorithm is proposed to account for the problem of SAR imaging with high squint angle. The measures of decoupling consist of second range compression (SRC), third order coupling compensation and range cell migration correction (RCMC). In addition, the type of RCMC is modified to eliminate target's movement...
This work proposes an efficient software implementation of circular buffer rate matching algorithm in Long Term Evolution Advanced (LTE-A). Rate matching algorithm in LTE-A performs bit re-positioning to randomize the data bits. Due to data format mismatch, such algorithm is inefficient in commodity word-based microprocessors. This work implements the transposed matrix with one or a few square sub-matrices,...
This paper proposes an improved Doppler Beam Sharpening (DBS) algorithm for missile-borne Synthetic Aperture Radar (SAR) based on Doppler localization equations, to gain a better azimuth resolution and reduce the heavy localization computation afford. Firstly, the azimuth resolution is improved by a modified reference function, with little extra computation. Then Doppler localization equations are...
In this work, we study the upper bound of second order statistical correlation. We provide a condition for a random variable reaching the upper-bound, and an algorithm that transform any variable to have the maximum second order statistical correlation.
User-friendly visual cryptography schemes (denoted as (n, n) — FVCSs) generate meaningful shares to cope the management problem of conventional visual cryptography. However, several issues still remain in this research field, including: pixel expansion, residual traces of cover images, low visual quality of meaningful shares and recovered images, lack of systematic encryption methods, and others....
Previous studies have shown how to “fingerprint” certain image processing operation. In this paper, we model the gray-level cumulative distribution of histogram-equalized image as discrete identity function, which is an intrinsic fingerprint produced by global histogram equalization processing. This model is shown to match well with the observed gray-level cumulative distribution. Based on the new...
Scans of double-sided documents often suffer from show-through distortions, where contents of the reverse side (verso) may appear in the front-side page (recto). Several algorithms employed for show-through removal from the scanned images, are based on linear mixing models, including blind source separation (BSS), non-negative matrix factorization (NMF), and adaptive filtering. However, a recent study...
The altitude information is very important for the safety of aircraft. Among many types of modulation, the Frequency Modulated Continuous Wave (FMCW) was the most common used in radar altimeter. Although classical Fast Fourier Transform (FFT) method has been successfully used in short range measurement for Radar Altimeter [1], the problem of altitude estimation in long distance for Radar Altimeter...
Vibration signature extraction and vehicle type identification are traditional aspirations in micro-Doppler domain. Radar echoes from vibrating targets can be modeled as frequency-modulated signals, with micro stochastic Doppler components in phase item. In this work, the sinusoidal frequency modulation Fourier transform (SFMFT) in sinusoidal frequency modulated signal space is proposed, which owns...
Subpixel detection is an important but difficult problem in hy-perspectral image. Due to the small size of the target, only spectral information can be used for detection. Many algorithms have been proposed to reduce this problem, and most of them assume that the distribution of hyperspectral image is multinormal. However, this assumption may not be an appropriate description of the distribution in...
Image forensics has now raised the anxiety of justice as increasing cases of abusing tampered images in newspapers and court for evidence are reported recently. With the goal of verifying image content authenticity, passive-blind image tampering detection is called for. More realistic open benchmark databases are also needed to assist the techniques. Recently, we collect a natural color image database...
For a three-node amplify-and-forward (AF) two-way relay network (TWRN), we investigate the power allocation problem during the channel training process for both terminals to estimate the global channel state information (CSI) of the whole network. This includes the power allocations between different training steps and among different nodes. Two power allocation schemes are proposed: a mean-square-error...
This paper provides a comprehensive overview on frequency synchronizations in LTE (Long Term Evolution) downlink transmission and presents the necessity to carry out dynamic Doppler tracking for LTE-based broadband communication on high speed rails (HSRs). Firstly, the fundamentals of frequency synchronization are introduced, followed by the discussion of dynamic Doppler shifts in HSR scenarios. Then,...
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