In the present study, we aimed at investigating a heart rate variability (HRV) biomarker that could be associated with the severity of the apnea-hypopnea index (AHI), which could be used for an early diagnosis of obstructive sleep apnea (OSA). This was a cross-sectional observational study on 47 patients (age 36 ± 9.2 standard deviation) diagnosed with mild (23.4%), moderate (34%), or severe (4...

Functional magnetic resonance imaging (fMRI) signal changes can be separated from background noise by various processing algorithms, including the well-known deconvolution method. However, discriminating signal changes due to task-related brain activities from those due to task-related head motion or other artifacts correlated in time to the task has been little addressed. We examine whether th...

Differential fault analysis (DFA) poses a significant threat to Advanced Encryption Standard (AES). Only a single faulty ciphertext is required for contemporary DFA to extract the secret key of AES using an average of 2 computations. Concurrent error detection (CED) is widely used to protect AES against DFA. Traditionally, these CEDs are evaluated with uniformly distributed faults, and the resu...

Differential fault analysis (DFA) poses a significant threat to Advanced Encryption Standard (AES). It has been demonstrated that DFA can use only a single faulty ciphertext to reveal the secret key of AES in an average of 230 computation. Traditionally, concurrent error detection (CED) is used to protect AES against DFA. However, we emphasize that conventional CED assumes a uniform distributio...

We report the modification of the scaling dynamics of human heart rate (HR in beat.min-1), speed (S in km.hour-1) and cardiac cost (the Heart Rate / Speed ratio, HRS in cardiac beats.m-1) was investigated in ten male subjects (35±5 yrs) who ran a marathon. The scaling power law was observed using the detrended fluctuation analysis (DFA) and the wavelet structure function. The corresponding scal...

In this paper we present improvements to the differential fault analysis (DFA) of the stream cipher Trivium proposed in the work of M. Hojśık and B. Rudolf. In particular, we optimize the algebraic representation of obtained DFA information applying the concept of Mutants, which represent low degree equations derived after processing of DFA information. As a result, we are able to minimize the ...

Combining different cryptanalytic methods to attack a cryptosystem became one of the hot topics in cryptanalysis. In particular, algebraic methods in side channel and differential fault analysis (DFA) attracted a lot of attention recently. In [13], Hojśık and Rudolf used DFA to recover the inner state of the stream cipher Trivium which leads to recovering the secret key. For this attack, they r...

For a non-negative integer k, a language is k-piecewise testable (k-PT) if it is a finite boolean combination of languages of the form Σa1Σ · · ·ΣanΣ for ai ∈ Σ and 0 ≤ n ≤ k. We study the following problem: Given a DFA recognizing a piecewise testable language, decide whether the language is k-PT. We provide a complexity bound and a detailed analysis for small k’s. The result can be used to fi...

A structure-activity relationship (QSAR) analysis of 19 thiazole derivatives with H1-antihistamine activity was carried out. The semi-empirical method AMI was employed to calculate a set of physicochemical parameters for investigated compounds. The principal component analysis (PCA), discriminant function analysis (DFA) and regression analysis (RA) were employed to reduce dimensionality and inv...