This paper explores the dependence of reliable decoding of grey toned QR codes on the technical characteristics of smartphone cameras marketed in the period between 2008 and 2012. The research consisted of taking a total of 12,150 QR code pictures with different grey tones, graphic patterns and error correction codes. This research answers the question whether today’s smartphones can decode suc...

Singularity problems of scatter matrices in Linear Discriminant Analysis (LDA) are challenging and have obtained attention during the last decade. Linear Discriminant Analysis via QR decomposition (LDA/QR) and Direct Linear Discriminant analysis (DLDA) are two popular algorithms to solve the singularity problem. This paper establishes the equivalent relationship between LDA/QR and DLDA. They ca...

We present progress towards developing a qualitative reasoning model of sustainable development issues in the Danube Delta Biosphere Reserve (DDBR), Romania, following a standardized methodology for conceptual description of QR case studies. Using the QR ontology, we have organized our expert knowledge about negative effects of water pollution on aquatic biota (especially on fish) and human hea...

QR codes, also known as matrix codes, are basically two dimensional barcodes embedded with data that can be decoded quickly for information. In this work, we present a novel use of QR codes. We show that QR codes can be used for covert communication using steganography. We also show in complete detail how to build QR code symbols with a hidden payload and how to extract this hidden information ...

Sliding window formulations of the fast QR and fast QR-lattice algorithms are presented. The derivations are based on the partial triangularization of raw data matrices. Three methods for window downdating are discussed: the method of plane hyperbolic rotations, the Chambers’ method, and the LINPACK algorithm. A numerically ill-conditioned stationary signal and a speech signal are used in finit...

We study the long time behavior of the Wasserstein gradient flow for an energy functional consisting of two components: particles are attracted to a fixed profile ω by means of an interaction kernel ψa(z) = |z|a , and they repel each other by means of another kernel ψr(z) = |z|r . We focus on the case of one space dimension and assume that 1 ≤ qr ≤ qa ≤ 2. Our main result is that the flow conve...

Virtual QR Code Stores are currently expanding globally and it is commonplace in the market to put emphasis on purely hedonic product assortments. This practice reflects the widespread assumption that hedonic products should be more effective to stimulate purchases because they facilitate impulse buying behavior. Contrary to this argumentation, the results of our study demonstrate that purchasi...

This paper presents a small-bulge multishift variation of the multishift QR algorithm that avoids the phenomenon of shift blurring, which retards convergence and limits the number of simultaneous shifts. It replaces the large diagonal bulge in the multishift QR sweep with a chain of many small bulges. The small-bulge multishift QR sweep admits nearly any number of simultaneous shifts—even hundr...

23.1 Let A be a nonsingular square matrix and let A = QR and A∗A = U∗U be QR and cholesky factorizations, respectively, with the usual normalization rjj, ujj > 0. Is it true or false that R = U? Solution: It is true. Since A is nonsingular, it will have a unique QR factorization with rjj > 0. Then we have A∗A = R∗Q∗QR = R∗R because Q is a unitary matrix. On the other hand, it is easy to see tha...