We describe a general framework for avoiding spurious eigenvalues — unphysical unstable eigenvalues that often occur in hydrodynamic stability problems. In two example problems, we show that when system stability is analyzed numerically using descriptor notation, spurious eigenvalues are eliminated. Descriptor notation is a generalized eigenvalue formulation for differential-algebraic equations...

Osteoarthritis (OA) causes progressive degeneration of articular cartilage and pathological changes in subchondral bone. These changes can be assessed volumetrically using micro-computed tomography (μCT) imaging. The local descriptor, i.e. local binary pattern (LBP), is a new alternative solution to perform analysis of local bone structures from μCT scans. In this study, different trabecular bo...

Texture has been recognized as an important visual primitive in image analysis. A widely used texture descriptor, which is part of the MPEG-7 standard, is that computed using multiscale Gabor filters. The high dimensionality and computational complexity of this descriptor adversely affect the efficiency of content-based retrieval systems. We propose a modified texture descriptor that has compar...

This paper proposes a robust and effective shape feature, which is based on a set of orthogonal complex moments of images known as Zernike moments. Zernike moment phase is usually not used in image description since it’s sensitive to image rotations. However, phase captures important image information, which is revealed by our numerical analysis of image reconstruction. We therefore propose com...

We propose a method for the assessment and visualization of high frequency regions of a multiresolution image. We combine both orientation tensor and multiresolution analysis to give a scalar descriptor of high frequency regions. High values of this scalar space indicate regions having coincident detail vectors in multiple scales of a wavelet decomposition. This is useful for finding edges, tex...

Local feature detection and description have gained a lot of interest in recent years since photometric descriptors computed for interest regions have proven to be very successful in many applications. In this paper, we propose a novel interest region descriptor which combines the strengths of the well-known SIFT descriptor and the LBP texture operator. It is called the center-symmetric local b...

Mel-frequency cepstral coefficients are used as an abstract representation of the spectral envelope of a given signal. Although they have been shown to be a powerful descriptor for speech and music signals, more accurate and easily interpretable options can be devised. In this study, we present and evaluate the shape-based spectral contrast descriptor, which is build up from the previously prop...

Although peas cv. master pea was registered more than 25 years ago in Egypt, this variety showed a remarkable superiority over the varieties grown all governorates of Egypt terms production, quality, and environmental adaptation to climate changes. This study intends assess cultivar's genetic traits, determine degree its deterioration time develop an appropriate plan for maintenance, improvemen...

Facial expression recognition (FER) is a crucial technology and a challenging task for human–computer interaction. Previous methods have been using different feature descriptors for FER and there is a lack of comparison study. In this paper, we aim to identify the best features descriptor for FER by empirically evaluating five feature descriptors, namely Gabor, Haar, Local Binary Pattern (LBP),...

A new method is proposed to check the detectability for a class of rectangular linear time invariant descriptor systems. The method is based on the properties of restricted system equivalent, derived here from a given descriptor system by means of simple matrix theory. Equivalence between the detectability of a given descriptor system and that of a normal system is established. The proposed res...