Search Results (76)

Background/Objectives: Type 2 diabetes mellitus (T2DM) is a growing burden in low- and middle-income countries, and non-invasive risk tools have been proposed where laboratory screening is not feasible. Fast-and-frugal decision trees (FFDTs) are transparent, non-compensatory rules that make sensitivity–specificity trade-offs explicit. We asked how far five routinely collected sociodemographic cues can go for classifying self-reported diabetes status and benchmarked FFDTs against the simplest possible alternatives. Methods: A cross-sectional secondary analysis of the 2016 South Africa Demographic and Health Survey Adult Health recode (N = 10,292; 459 self-reported cases, 4.46%) was carried out. Five binary cues were derived: age category, household wealth, employment, education and sex. Data were split 70/30 into development and a locked hold-out set. Three purpose-specific FFDTs were selected by 5 × 10-fold cross-validation within the development data only, frozen, and then evaluated once on the hold-out set. Comparators were a pre-specified age-only rule and logistic regression using the same five predictors at a development-derived Youden threshold. We report survey-weighted estimates, internal–external cross-validation across nine provinces, external validation in 12 further DHS, subgroup performance, and a log–log analysis of error against training sample size. Results: On the hold-out set the balanced screening FFDT achieved sensitivity 0.920 (95% CI 0.862–0.959), specificity 0.585 (0.567–0.602) and balanced accuracy 0.752 (0.727–0.776). The pre-specified age-only rule achieved balanced accuracy 0.751 (0.724–0.775), while logistic regression at the development-derived Youden threshold achieved 0.766 (0.735–0.797). Across 50 independent splits, the case-finding FFDT was arithmetically identical to the age-only rule in every split; the balanced FFDT exceeded it by a median of 0.001 (95% range −0.004 to +0.025); the referral-minimisation FFDT was worse by a median of 0.124. Performance was stable across provinces (balanced accuracy 0.731–0.801) but degraded across countries (0.508–0.724), with referral rate ranging from 0.225 to 0.806. Error scaled with training size as beta = −0.044 (95% CI −0.063 to −0.025). Conclusions: Transparent decision trees built from non-invasive sociodemographic cues classify self-reported diabetes status no better than a single question about age, do not transport reliably across countries, and are unlikely to be materially improved by simply increasing the training sample size. Their value lies in auditability rather than accuracy. Progress in low-burden risk stratification for T2DM in these settings will require cues that carry a biological rather than health system signal. Full article

Arrange the integers $1,2,\dots ,n$ on a circle and, for a fixed $k\ge 1$, let $s_i$ be the sum of the k consecutive entries starting at position i (indices taken modulo n). For a circular permutation $\pi$, define the range $R\left(\pi \right)={max}_i{s}_i-{min}_i{s}_i,$ and let $w(n,k)$ be the minimum value of $R\left(\pi \right)$ over all circular permutations of $\{1,\dots ,n\}$. We obtain three structural results. First, we prove the complement symmetry $w(n,k)=w(n,n-k)$. Second, we determine the first nontrivial arithmetic progression case $n=2k+1$ exactly: $w(2k+1,k)=2⌈{\displaystyle \frac{k}{2}}⌉.$ Third, we determine the structured regime $n=k^2+1$ exactly: $w(k^2+1,k)=k.$ The proofs combine averaging lower bounds on the progression $n\equiv 1\left(\mathrm{mod}k\right)$ with explicit constructions: a parity-sensitive two-block arrangement for $n=2k+1$ and a $k\times k$ array construction for $n=k^2+1$. Full article

Numerical computation of the rate–distortion (RD) function is a key problem in RD theory. Thus far, efficient algorithms have been well studied for discrete sources, but for continuous sources, there is still lack of a rigorously developed solution. In this article, an integrated approach is conducted that bridges RD problems of continuous memoryless sources and discrete numerical algorithms. First, we analyze and establish the theoretical convergence guarantee when progressively approaching the continuous RD problem via a sequence of discrete problems. Next, discrete algorithms including the Blahut–Arimoto (BA) and constrained BA algorithms are reviewed, and estimates of their required amount of arithmetic operations to attain $\epsilon$-accuracy in solving the continuous RD problem are derived. Finally, acceleration techniques that exploit structures of special distortion measures (i.e., squared-error and absolute-error) are developed. Full article

Background/Objectives: Advanced-stage mycosis fungoides (MF) and Sézary syndrome (SS) are aggressive forms of cutaneous T-cell lymphoma (CTCL) for which treatment options are limited and prognosis is poor. Brentuximab vedotin (BV), an anti-CD30 antibody–drug conjugate, has demonstrated high response rates in patients with CD30 expression ≥ 10%. However, data on its efficacy in cases with low CD30 expression (<10%) remain scarce. Methods: This retrospective analysis evaluated the real-world efficacy of BV in patients with advanced-stage MF/SS and low CD30 expression. A retrospective analysis was conducted on 32 patients across 11 German CTCL expert centers. All patients had advanced-stage MF or SS with CD30 expression < 10% and received BV at the standard dose. Treatment response was assessed using EORTC-ISCL criteria. Results: All patients had received prior systemic therapies (median: 3) with 36% having undergone prior mono- or polychemotherapy. The study population included 30 MF (stage IIB) and two SS cases. The overall response rate (ORR) in this population was 53.1% (17/32). A complete response (CR) was achieved in 12.5% (4/32), a partial response (PR) was achieved in 40.6% (13/32), stable disease (SD) was seen in 18.8% (6/32), and progressive disease (PD) was seen in 28.1% (9/32). The median progression-free survival (PFS) was 4.0 months (arithmetic mean: 6.38; range: 0.5–15.5), and the median time to next treatment (TTNT) was 7.25 months (arithmetic mean: 7.30; range: 2.00–15.5). Conclusions: BV demonstrated encouraging activity in heavily pretreated advanced MF/SS with low CD30 expression, achieving an ORR comparable to that observed in patients with higher CD30 levels. While response rates were similar, PFS was shorter. These findings suggest that BV remains a potential therapeutic option in this patient population and merits further prospective investigation. Full article

This study investigated the impact of a Science-Technology-Society (STS)-based nature education program on the creativity levels of middle school students. Recognizing creativity as a crucial human capacity for individual and societal progress, the research focused on its core elements, including the generation of novel solutions, diverse perspectives, and original ideas. The STS approach, which emphasizes constructivist learning and problem-solving within real-world contexts, was employed to enhance skills such as visualization, mental image formation, combining objects and ideas innovatively, generating alternative uses, and designing tools and machines. A quasi-experimental single-group pre-test–post-test design was utilized. Participants included 60 middle school students (15 from each of grades 5 to 8) comprising 30 gifted students enrolled in Science and Art Centers simultaneously. Students’ creativity levels were assessed using the Test for Creative Thinking-Drawing Production (TCT-DP), which is a figural test measuring holistic creativity across 14 criteria. Data were analyzed using arithmetic means, paired-sample t-tests, and independent-sample t-tests. The results demonstrated a statistically significant and large improvement in overall creativity following the intervention (t(59) = 7.14, p < 0.001; Cohen’s d = 0.92). Notably, no significant differences in creativity were observed between the gifted and non-gifted groups either before or after the program. These findings align with previous research indicating that out-of-school environmental and nature-based activities can enhance students’ creative thinking and problem-solving skills. The study suggests that STS-based nature education effectively fosters creativity and should be integrated into curricula to strengthen problem-solving, perspective-taking, and idea generation skills. Full article

The P300 evoked potential, recorded via electroencephalography, serves as a relevant marker of attentional allocation and cognitive workload. This work extracts and analyzes event-related potentials that reflect variations in the cognitive state of military pilots during a complex simulated flight scenario coupled with simultaneous mental arithmetic tasks. The experiment was conducted at the Academia General del Aire (Spain) with 14 military pilots using a high-fidelity flight simulator. The experimental protocol involved dynamic flight instructions combined with arithmetic tasks designed to elicit varying cognitive loads. The results revealed a significant decrease in P300 amplitude across successive sessions, indicating a progressive reduction in attentional engagement due to task habituation and increased cognitive automaticity. Concurrently, P300 latency for correct responses decreased significantly, demonstrating enhanced efficiency in cognitive stimulus evaluation over repeated exposure. However, incorrect responses failed to yield robust results due to an insufficient number of trials. These findings validate the use of P300 as an objective indicator of cognitive workload variations in realistic aviation contexts. Full article

Lattice-based cryptography (LBC) is an essential direction in the fields of homomorphic encryption (HE), zero-knowledge proofs (ZK), and post-quantum cryptography (PQC), while number theoretic transformations (NTT) are a performance bottleneck that affects the promotion and deployment of LBC applications. Field-programmable gate arrays (FPGAs) are an ideal platform for accelerating NTT due to their reconfigurability and parallel capabilities. High-level synthesis (HLS) can shorten the FPGA development cycle, but for algorithms such as NTT, the synthesizer struggles to handle the inherent memory dependencies, often resulting in suboptimal synthesis outcomes for direct designs. This paper proposes a systematic HLS co-design to progressively guide the synthesis of NTT accelerators. The approach integrates several key techniques: arithmetic module resource optimization, conflict-free butterfly scheduling, memory partitioning, and template-based automated design fusion. It reveals how to resolve pipeline bottlenecks in HLS-based designs and expand parallel processing, guiding microarchitecture iterations to achieve an efficient design space. Compared to existing HLS-based designs, the area-latency product achieves a performance improvement of 1.93 to 191 times, and compared to existing HDL-based designs, the area-cycle product achieves a performance improvement of 1.7 to 10.6 times. Full article

We present an extension of the Dirichlet-type prime number theorem to weighted counting functions, the importance of which has recently been recognized for formulating Chebyshev’s bias. Moreover, we prove that their difference ${\pi }_w(x;q,a)-{\pi }_w(x;q,b)$ ($0\le w<1/2$) changes its sign infinitely many times as x grows for any coprime $a,b$$(a\ne b)$ with q, under the assumption that Dirichlet L-functions have no real nontrivial zeros. This result gives a justification of the theory of Aoki–Koyama that Chebyshev’s bias is formulated by the asymptotic behavior of ${\pi }_w(x;q,a)-{\pi }_w(x;q,b)$ at $w=1/2$. Full article

This paper extends the previous work by the author on m-null pairs of operators in Hilbert space. If an elementary operator L has elementary symbols A and B that are p-null and q-null, respectively, then L is $(p+q-1)$-null. Here, we prove the converse under strictness conditions, modulo some nonzero multiplicative constant—if L is strictly $(p+q-1)$-null, then a scalar $\lambda \ne 0$ exists such that $\lambda A$ is strictly p-null and ${\lambda }^{-1}B$ is strictly q-null. Our constructive argument relies essentially on algebraic and combinatorial methods. Thus, the result obtained by Gu on m-isometries is recovered without resorting to spectral analysis. For several operator classes that generalize m-isometries and are subsumed by m-null operators, the result is new. Full article

The broadening adoption of interconnected systems within smart city environments is fundamental for the progression of digitally driven economies, enabling the refinement of city administration, the enhancement of public service delivery, and the fostering of ecologically sustainable progress, thereby aligning with global sustainability benchmarks. However, the pervasive distribution of Internet of things (IoT) apparatuses introduces substantial security risks, attributable to the confidential nature of processed data and the heightened susceptibility to cybernetic intrusions targeting essential infrastructure. Commonly, these devices exhibit deficiencies stemming from restricted computational capabilities and the absence of uniform security standards. The resolution of these security challenges is paramount for the full realization of the advantages afforded by IoT without compromising system integrity. Cryptographic protocols represent the most viable solutions for the mitigation of these security vulnerabilities. However, the limitations inherent in IoT edge nodes complicate the deployment of robust cryptographic algorithms, which are fundamentally reliant on finite-field multiplication operations. Consequently, the streamlined execution of this operation is pivotal, as it will facilitate the effective deployment of encryption algorithms on these resource-limited devices. Therefore, the presented research concentrates on the formulation of a spatially and energetically efficient hardware implementation for the finite-field multiplication operation. The proposed arithmetic unit demonstrates significant improvements in hardware efficiency and energy consumption compared to state-of-the-art designs, while its systolic architecture provides inherent timing-attack resistance through deterministic operation. The regular structure not only enables these performance advantages but also facilitates future integration of error-detection and masking techniques for comprehensive side-channel protection. This combination of efficiency and security makes the multiplier particularly suitable for integration within encryption processors in resource-constrained IoT edge nodes, where it can enable secure data communication in smart city applications without compromising operational effectiveness or urban development goals. Full article

A novel photonics-assisted technique for generating reconfigurable frequency hopping (FH) signals is proposed and demonstrated through optical comb filtering (OCF). The arithmetic progression of frequency difference between OCF passbands and optical frequency comb lines is exploited to enable wavelength selection controlled by an intermediate frequency signal, with ultra-wideband FH signals subsequently being generated through optical heterodyning. Comprehensive theoretical and numerical investigations are conducted, demonstrating the successful generation of diverse FH waveforms including 5-, 10-, and 25-level stepped frequency signals, Costas-coded patterns, as well as complex wideband signals such as 30 GHz linear frequency modulated and 24 GHz sinusoidal chirped waveforms. Critical system considerations including laser frequency stability, FH speed, and parameter optimization are examined. Wide tunable bandwidth exceeding 30 GHz, good stability, and inherent compatibility with photonic integration is achieved, showing significant potential for advanced applications in cognitive radio and modern radar systems where high-performance frequency-agile signal generation is required. Full article

This study aimed to clarify the sequence characteristics and spatiotemporal expression patterns of the insulin-like growth factor 1 receptor (IGF1R) gene in Alopex lagopus (Arctic fox), thereby addressing the existing knowledge gap regarding IGF1R-mediated growth regulation in this species. The findings establish a crucial foundation for subsequent investigations into the correlation between this gene and Arctic fox growth traits. Specific primers were designed based on the cDNA sequence of the canine IGF1R gene (Accession No. XM_545828). The full-length coding sequence (CDS) of the Arctic fox IGF1R gene (1617 bp, encoding 538 amino acids) was successfully cloned via RT-PCR. Phylogenetic analysis using the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) algorithm revealed a 99% sequence homology in the IGF1R gene between the Arctic fox and canine, confirmed their closest evolutionary relationship. Protein characterization showed that the IGF1R protein has a molecular weight of 60.62 kDa (theoretical isoelectric point pI = 5.15), containing one fibronectin type-III domain and one tyrosine kinase domain, classifying it as an acidic hydrophilic transmembrane protein. Phosphorylation site prediction identified 27 phosphorylation sites, with secondary structures dominated by α-helices (26.39%) and random coils (52.79%). The IGF1R gene displayed significant tissue-specific expression variations across 12 examined tissues in Arctic foxes: highest expression levels in testis, minimal expression in stomach, and no detectable expression in duodenum. Spatiotemporal expression analysis revealed that in 2-, 4-, and 6-month-old individuals, hepatic IGF1R exhibited a progressive increase, testicular expression reached peak levels at 6 months, and skeletal muscle demonstrated transient upregulation peaking at 4 months. These spatiotemporal expression patterns suggest that IGF1R may participate in metabolism and organ developmental processes during critical growth stages of Arctic foxes through tissue-specific regulation. Full article

The unified hardening model for clays and sands (CSUH) can adequately represent the stress–strain characteristics of various soil types. However, being an incremental elastoplastic constitutive model, the CSUH model requires extensive iterative computations during parameter identification, resulting in significant computational time. To improve computational efficiency, this study derives the elastoplastic compliance matrix and stress–strain incremental relationships under different stress paths, eliminating the repeated solving of equations typically required during iterative processes. Furthermore, a dynamic step size iterative method is proposed based on the changing slope characteristics of the stress–strain curves. This method divides the total axial strain into two segments: in the initial segment (approximately the first 30% of total strain), where the curve slope is steep, smaller step sizes with arithmetic progression distribution are employed, while in the latter segment (approximately the remaining 70%), characterized by a gentle curve slope, larger and uniformly distributed step sizes are adopted. Comparative analyses between the proposed dynamic step size method and the traditional constant-step iterative method demonstrate that, under the premise of ensuring calculation accuracy, the dynamic step size method significantly reduces the iteration steps from 3000 to 50, thus decreasing the computational time by approximately 47 times. Finally, the proposed method is applied to parameter identification of Fujinomori clay, calcareous sand, and Changhe dam rockfill materials using the CSUH model. The predictions closely match experimental results, confirming the CSUH model’s capability in accurately describing the mechanical behaviors of different soils under various stress paths. The dynamic step size iterative approach developed in this study also provides valuable insights for enhancing computational efficiency and parameter identification of other elastoplastic constitutive models. Full article

In the field of neuroeconomics, the assessment of cognitive workload is a crucial issue with significant implications for real-world applications. Previous research has made progress in task-based germane cognitive load classification, but decentralized studies focusing on task-independent assessment have often produced less than optimal results. In this study, we present a stacked graph attention convolutional networks (SGATCNs) model to tackle the challenges related to task-independent cognitive workload assessment using EEG spatial information. The model employs the differential entropy (DE) and power spectral density (PSD) features of each EEG channel across four frequency bands (delta, theta, alpha, and beta) as node information. For the construction of the network structure, phase-locked values (PLVs), phase-lag indices (PLIs), Pearson correlation coefficients (PCCs), and mutual information (MI) are utilized and evaluated to generate a functional brain network. Specifically, the model aggregates spatial information on the dynamic map by stacking the graph attention layers and utilizes the convolution module to extract the frequency domain information from between the networks under each frequency band. We conducted a cognitive workload experiment with 15 subjects and selected three representative psychological experimental task paradigms (N-back, mental arithmetic, and Sternberg) to induce different levels of cognitive workload (low, medium, and high). Our framework achieved an average accuracy of 65.11% in recognizing the task-independent cognitive workload across the three scenarios. Full article

The aim of this article is to investigate the relations between the exponent of the convergence of sequences and other characteristics defined for monotone sequences of positive numbers. Another main goal is to characterize such monotone sequences $\left(a_n\right)$ of positive numbers that, for each $n\ge 2$, satisfy the equality $a_n=K(a_{n-1},a_{n+1})$, where the function $K:{\mathbb{R}}^{+}\times {\mathbb{R}}^{+}\to {\mathbb{R}}^{+}$ is the mean, i.e., each value of $K(x,y)$ lies between $min\{x,y\}$ and $max\{x,y\}$. Well-known examples of such sequences are, for example, arithmetic (geometric) progression, because starting from the second term, each of its terms is equal to the arithmetic (geometric) mean of its neighboring terms. Furthermore, this accomplishment generalized and extended previous results, where the properties of the logarithmic sequence $\left(a_n\right)$ are referred to, i.e., in such a sequence that every $n\ge 2$ satisfies $a_n=L(a_{n-1},a_{n+1})$, where $L(x,y)$ is the logarithmic mean of positive numbers $x,y$ defined as follows: $L(x,y):=\left\{\begin{array}{ccc}{\displaystyle \frac{y-x}{lny-lnx}}\hfill & \mathrm{if}\hfill & x\ne y,\hfill \\ x\hfill & \mathrm{if}\hfill & x=y.\hfill \end{array}\right.$ Full article