Hanoi Architectural University

This study proposes a novel nonlinear modeling and solution approach to analyze the geometrically nonlinear behavior of beams subjected to combined eccentric compressive loads and thermal effects. General governing equations for large-displacement beams under the simultaneous action of eccentric compression and temperature fields are formulated analytically. A numerical solution procedure for the nonlinear governing equations is developed by transforming the system of nonlinear equations into a least-squares optimization problem. Based on the Levenberg-Marquardt algorithm, a computational code is implemented in MATLAB to solve the proposed nonlinear optimization problem. The accuracy of the developed method is verified through comparison with classical solutions using elliptic integrals, showing excellent agreement. The influences of load eccentricity and temperature on the nonlinear response of beams are also investigated in detail. The simple and efficient approach proposed in this study offers a promising tool for practicing engineers in the design of beams with large displacements under combined eccentric and thermal loading.

Inefficient non-clinical information delivery in medical centers burdens patients and staff, despite the potential of LLM-enhanced humanoid robots. Practical deployment faces critical hurdles: high cloud-LLM latencies, on-robot computational limits, and lacking secure, distributed knowledge sharing under strict privacy regulations. This paper introduces Dynamic LLM Routing for Smart Medical Robots, a framework designed for clinical question-answering systems. Our hybrid edge-cloud architecture integrates three core innovations: a dynamic LLM selection mechanism routing queries based on context (complexity, domain, and urgency), an optimized edge computing layer for privacy-preserving local processing, and an intelligent, privacy-preserving caching system enabling secure knowledge sharing and continuous learning. Evaluated on 7,500 authentic hospital queries, our system achieved a 50% reduction in average response latency (0.62s vs. 1.23s), an 89.7% completion rate, and a 62% reduction in external data transmission (73% cache hit rate). These results demonstrate our framework's efficacy in enabling scalable, efficient, and privacy-compliant AI-powered humanoid robots for critical healthcare information delivery.

This paper investigates the boundedness properties of a convolution operator associated with the fractional Fourier transform (often abbreviated as FrFT) of order α . The operator under study incorporates chirp weight functions γ _1,2(x)=e^± i(x-a(α )x^2) and serves as a natural generalization of classical convolution structures within the fractional domain, which was first introduced in Wirel. Pers. Commun. 92, 623–637, (2017). First, we establish a Young-type inequality for this operator, proving that it maps L_p(ℝ)× L_q(ℝ) into L_r(ℝ) for p,q,r>1 satisfying 1/p+1/q=1+1/r , with an explicit constant depending solely on α . Second, we prove a Hausdorff–Young type inequality which guarantees boundedness into the conjugate space L_s_1(ℝ) whenever 1≤ p,q,s≤ 2 and 1/p_1 +1/q_1=1/s , thereby extending the range of exponents to the dual setting. Third, we derive a Saitoh-type weighted inequality valid for all p>1 (including p=2 ), providing L_p -boundedness with respect to suitable weight functions. The proofs rely on the Riesz-Thorin interpolation theorem, Hölder’s inequality, and Plancherel-type identities for the FrFT. These results unify and substantially extend classical convolution estimates to the fractional Fourier framework.

Iseluxine (ISL), an isoquinolinone alkaloid derived from Iseia luxurians, exhibits remarkable antioxidant potential, surpassing conventional antioxidants such as vitamin C and BHA in vitro. To clarify its radical-scavenging behavior, density functional theory (DFT) calculations were conducted against key reactive oxygen and nitrogen species (ROS and RNS), including HO•, CH₃O•, CH₃OO•, HOO•, NO•, NO₂•, and O₂•–. Three mechanisms, formal hydrogen atom transfer (fHAT), sequential electron transfer–proton transfer (SETPT), and sequential proton loss–electron transfer (SPLET) were examined in gas, water, and lipid-like (pentylethanoate) media. Thermodynamic analysis identified the O6–H bond as the most reactive site due to its low bond dissociation enthalpy and proton affinity. Kinetic modeling indicated efficient HOO• scavenging via the SET pathway in water, with a rate constant of 1.8 × 106 M⁻1 s⁻1, significantly higher than that of Trolox. ISL also showed strong activity against CH₃O•, CH₃OO•, and NO₂, but limited reactivity toward NO, and O₂•–, emphasizing its selective antioxidant potential. Density functional theory (DFT) calculations were performed using the M06-2X functional with the 6-31G(d,p)//6–311 + + G(d,p) basis set for single-point energy, geometry optimizations and kinetic calculations. Thermodynamic and kinetic parameters were obtained following the QM-ORSA protocol, combined with the SMD solvation model to simulate aqueous and pentylethanoate media.

Understanding the antioxidant mechanism of small bioactive molecules at the molecular level is essential for evaluating their potential application in biological and aqueous systems. In this work, the antioxidant activity of maculosin (MA) was systematically investigated in aqueous and lipid-like environments using quantum chemical approaches. Frontier molecular orbital and molecular electrostatic potential analyses reveal that MA possesses favorable electronic features for electron and hydrogen atom donation. Thermodynamic descriptors indicate that the O19–H, C3–H, and C7–H sites are the most reactive positions, while the N8–H site is inactive. Mechanistic evaluation shows that in water, MA predominantly scavenges radicals via a single-electron transfer pathway, leading to an overall rate constant markedly higher than that of the reference antioxidants Trolox and BHT. In contrast, in a lipid-like medium, the antioxidant activity of MA is governed by formal hydrogen atom transfer at carbon-centered sites, resulting in lower overall reactivity. These findings demonstrate a strong solvent-dependent antioxidant behavior and highlight MA as a highly efficient radical scavenger, particularly in polar media. All calculations were performed using density functional theory. Geometry optimizations and frequency calculations were carried out at the DFT/M06-2X/6–311 + + G(d,p) level to obtain stable structures and thermodynamic parameters in both aqueous and lipid-like phases using an implicit solvation model. Frontier molecular orbital energies, molecular electrostatic potential maps, and spin density distributions were analyzed to identify reactive sites. Thermodynamic descriptors including bond dissociation enthalpy, ionization potential, and proton affinity were calculated to assess the feasibility of fHAT, SETPT, and SPLET mechanisms. Reaction kinetics with the HOO• radical were evaluated following the QM-ORSA protocol to determine activation free energies, rate constants, and branching ratios. All quantum chemical calculations were performed using Gaussian 09 software packages.