Search Results (865)

This paper designs a statistical channel state information-based pinching antenna system for short-packet communication (SPC). To maximize the average maximal achievable rate (MAR) under physical collision-avoidance constraints, we formulate a highly non-convex geometry optimization problem, which is solved by our proposed novel phase-domain proximal policy optimization (PPO) framework. Unlike conventional coordinate-based approaches, the agent operates in a dual-component trigonometric phase domain, and the generated phase actions are mapped to feasible antenna positions via a customized phase-domain action mapping, which fundamentally avoids the $0/2\pi$ phase discontinuity and ensures stable learning. To evaluate the reliability of SPC, we derive a tractable statistical characterization of the received signal-to-noise ratio based on a mixture Gamma approximation over spatially correlated Rician fading channels, leading to a closed-form approximation for the average block error rate (BLER). A bisection search algorithm is further developed to minimize the required blocklength under the target reliability constraint. Simulation results demonstrate that the proposed phase-domain PPO scheme significantly outperforms the conventional algorithms in terms of average MAR, average BLER, and blocklength efficiency, with the performance gain becoming more pronounced as the number of antennas per waveguide increases. Full article

After long-term waterflooding in offshore oilfields, the remaining oil becomes highly dispersed and discontinuous. To address the limitations of classical waterflooding theory in describing the effects of microscopic oil occurrence and stress differences on oil-phase flow, this study investigated oil–water two-phase flow during heavy-oil waterflooding using core samples from the Bohai Oilfield. The evolution of the oil-phase starting pressure gradient at different water-cut stages was measured through core two-phase steady-state displacement experiments. By combining in situ core CT scanning with pore-scale phase-field simulations, the multi-form start-up mechanisms and microscopic causes of the oil phase were clarified. The fractal characteristics of the reservoir pore structure were further incorporated to establish a calculation method for the multi-form start-up resistance of the oil phase. The results show that, as the water cut increases, the starting pressure gradient of the oil phase exhibits a nonlinear increasing trend. At a water cut of 90%, the oil-phase starting pressure gradient is approximately 7–8 times that of the pure oil phase. Meanwhile, the oil phase gradually transforms from a continuous phase to a discontinuous phase, with a smaller pore radius and a larger surface area per unit volume. Owing to the Jamin effect, capillary force exerts a stronger influence on oil-phase flow, resulting in a significant increase in the starting pressure gradient during the ultra-high water-cut stage. These findings provide a pore-scale explanation for the increase in oil-phase starting pressure gradient during ultra-high water-cut waterflooding and offer a theoretical basis for the sustainable development of mature offshore oilfields. Full article

Background: Anti-amyloid monoclonal antibodies represent the first disease-modifying therapeutic strategy targeting amyloid-β pathology in early Alzheimer’s disease (AD). Although several agents have demonstrated the ability to reduce cerebral amyloid burden, their clinical efficacy and safety remain subjects of substantial scientific and regulatory debate. This study aimed to synthesize randomized evidence evaluating the benefit–risk profile of anti-amyloid monoclonal antibodies in biomarker-confirmed early AD. Methods: A systematic review and classical pairwise meta-analysis of randomized controlled trials (RCTs) was conducted following the PRISMA 2020 guidelines. PubMed/MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched for phase III placebo-controlled trials evaluating lecanemab, donanemab, aducanumab, and gantenerumab in patients with mild cognitive impairment due to AD or mild AD dementia with biomarker confirmation of amyloid pathology. The primary outcome was change from baseline in the Clinical Dementia Rating–Sum of Boxes (CDR-SB) at the longest available follow-up. Safety outcomes included amyloid-related imaging abnormalities with edema or effusion (ARIA-E), amyloid-related imaging abnormalities with hemorrhage (ARIA-H), serious adverse events, and treatment discontinuation. Random-effects meta-analyses were performed. Results: Six randomized comparisons derived from four phase III trials involving 7695 participants met the eligibility criteria. Anti-amyloid monoclonal antibodies were associated with a statistically significant slowing of clinical progression compared with placebo (pooled mean difference in CDR-SB: −0.42 points; 95% CI −0.59 to −0.25; I² = 78%). The observed effect was primarily driven by trials of lecanemab and donanemab, whereas aducanumab demonstrated discordant results across trials and gantenerumab showed no clinically meaningful benefit. Despite statistical significance, the magnitude of the pooled effect approached the lower boundary of the minimal clinically important difference reported for CDR-SB in early AD. Treatment was associated with a markedly increased risk of ARIA-E (pooled risk ratio 10.1; 95% CI 7.8–13.0), with moderate heterogeneity across studies. Most ARIA-E events were asymptomatic and detected through protocol-mandated MRI monitoring. Conclusions: In biomarker-confirmed early Alzheimer’s disease, anti-amyloid monoclonal antibodies produce a statistically significant but modest slowing of clinical decline accompanied by a substantially increased risk of ARIA. The benefit–risk profile appears heterogeneous across individual antibodies and may reflect pharmacological differences in amyloid targeting and clearance mechanisms. These findings support cautious, individualized use of anti-amyloid therapies and highlight the need for longer-term studies to determine whether short-term slowing of decline translates into clinically meaningful disease modification. Full article

Background: Penetrating keratoplasty (PK) is a technically demanding corneal transplant procedure frequently performed in elderly patients with substantial systemic comorbidities. In this population, an anesthetic strategy that ensures hemodynamic stability, cooperative sedation, adequate analgesia, and preserved spontaneous ventilation is highly desirable. Dexmedetomidine, a highly selective alpha2-adrenergic agonist, provides “cooperative” sedation with minimal risk of respiratory depression and additional sympatholytic benefits. Methods: This single-center retrospective observational case series included 50 consecutive patients (American Society of Anesthesiologists [ASA] II–III, age 50–90 years) undergoing PK under sub-Tenon block combined with continuous dexmedetomidine infusion. Dexmedetomidine was administered without a loading bolus at 0.7 mcg/kg/h for 10–15 min, then reduced to 0.5 mcg/kg/h, targeting a Ramsay Sedation Scale (RSS) score of 2–3. The sub-Tenon block was performed using a mixture of levobupivacaine 0.5% and lidocaine 2% (3–5 mL). Heart rate (HR), mean arterial pressure (MAP), oxygen saturation (SpO₂) and RSS were recorded in nine predefined perioperative phases. Data were analyzed descriptively. Results: The mean age was 72 ± 9 years; 52% of patients were ASA III. Hypertension was present in all patients; 30% had cardiovascular disease, 28% diabetes mellitus type II, and 30% chronic obstructive pulmonary disease. Progressive, controlled bradycardia was observed (mean HR decreased from 76 to 57 beats/min during graft transplantation), while MAP gradually decreased from hypertensive baseline values (150–160 mmHg) to an optimal intraoperative range of 115–130 mmHg, without episodes of clinically significant hypotension. SpO₂ remained stable at 98–99% throughout all phases, with no episodes of desaturation or need for airway intervention or supplemental oxygen. Target sedation (RSS 2–3) was achieved in all patients (median RSS 3), with preserved spontaneous breathing and cooperation. Sub-Tenon block-related bulging occurred in 6% of cases. No episodes of clinically significant bradycardia, malignant arrhythmia, respiratory compromise, or need to discontinue dexmedetomidine were recorded. No opioids or non-steroidal analgesics were required intraoperatively or in the early postoperative period. Conclusions: The combination of sub-Tenon block and continuous dexmedetomidine sedation without a loading bolus represents a hemodynamically stable and respiratory-safe anesthetic strategy for PK in elderly, high-risk patients. These preliminary, hypothesis-generating findings suggest that the protocol provides stable surgical conditions and a favorable safety profile, justifying future prospective randomized controlled trials to establish its comparative efficacy against general anesthesia or standard sedative regimens. Full article

Background/Objectives: To analyse postoperative pain trajectories after anterior cruciate ligament (ACL) reconstruction using data from a digital rehabilitation system, and to determine (i) whether combined ligament injuries are perceived as more painful than isolated ACL tears, (ii) which patient characteristics are associated with clinically relevant pain (visual analogue scale [VAS] > 5), and (iii) whether higher early pain is associated with later discontinuation of digital monitoring. Methods: This retrospective cohort study used routine data recorded by a validated sensor-based home rehabilitation system in patients after ACL reconstruction. This approach has previously been used to analyse functional recovery trajectories. All patients with ACL-related indications who performed at least one postoperative test were included and classified into four groups: isolated ACL rupture, ACL + meniscus, ACL + collateral ligament, and ACL + collateral ligament + meniscus. Pain during exercises and tests was recorded on a 0–10 VAS. High pain was defined as VAS > 5. Group comparison between indication types, anthropometric and activity-related variables and the proportion of high-pain events were performed using chi-square tests. Early pain (first postoperative month) was analysed in relation to the presence of later tests (≥3 months) to explore associations with discontinuation of digital monitoring. Results: Combined ligament injuries showed a significantly higher proportion of high-pain events during rehabilitation compared with isolated ACL ruptures (5.8% vs. 2.4%, overall p < 0.001). In particular, combined ligament injuries with ACL + collateral ligament rupture were associated with a greater share of VAS > 5 ratings in the early rehabilitation phases. No relevant association was observed between sex or BMI category and the occurrence of high pain, while age group showed an overall association without a consistent directional pattern. Sport activity level showed a strong relationship with high pain (p < 0.001). Early pain demonstrated a small but statistically significant negative correlation with later test participation (r = −0.15, approximately 2% of variance, p = 0.0076); however, this association was attenuated and no longer statistically significant when analysed using mixed-effects models accounting for within-patient clustering, indicating that patients with higher early pain tended to discontinue digital monitoring. Conclusions: Digital routine data after ACL reconstruction suggest that (i) combined ACL–collateral ligament injuries are perceived as more painful than isolated ACL tears, (ii) high postoperative pain is more closely related to activity level and injury pattern than to sex or BMI, while age group shows an overall but non-directional association, and (iii) higher early pain shows a weak bivariate correlation with digital disengagement that was not confirmed in mixed-effects models. Pain is therefore an exploratory marker warranting further investigation, rather than a confirmed independent predictor of adherence in app-based rehabilitation. Full article

This study aims to identify the optimal aging regime that balances strength and intergranular corrosion (IGC) resistance in a 2060 Al–Li alloy under T8 temper. The evolution of microstructure, mechanical properties, and IGC behavior was systematically investigated across various aging conditions. The most relevant results show that the optimal regime for the 3% pre-stretched alloy is 150 °C for 32–48 h. At the peak-aged state (150 °C/48 h), the alloy achieves a yield strength (YS) of 521 MPa and ultimate tensile strength (UTS) of 541 MPa in the longitudinal (L) direction, and 486 MPa and 548 MPa in the long-transverse (LT) direction, with elongations of 11.1% and 12.2%, respectively. Under this condition, the corrosion mode shifts from IGC to pitting, with a maximum pitting depth of 98.6 μm. Microstructural analyses confirm that the T₁ (Al₂CuLi) phase is the primary strengthening precipitate. Critically, as aging temperature and time increase, T₁ plates extensively nucleate and grow within grain interiors, while their distribution at grain boundaries (GBs) becomes discontinuous. This discontinuous GB precipitate morphology interrupts continuous anodic dissolution channels, thereby significantly enhancing localized corrosion resistance. Notably, these findings can offer practical guidance for industrial heat treatments of third-generation Al–Li alloys, particularly for safety-critical aerospace components where both strength and corrosion resistance are mandatory. Full article

Background: Alcohol use disorder (AUD) is a grave mental health condition that can result in significant health and social consequences. The medications Naltrexone and Nalmefene are indicated for the treatment of AUD, with Naltrexone having received the most extensive research attention. Methods: The majority of papers assessing universal measures of alcohol consumption employed two primary metrics: total alcohol consumption (TAC) and the number of days per month where individuals engaged in heavy drinking (HDD). Indicators pertaining to the maintenance of complete abstinence were excluded due to the absence of sufficient data. The safety of both substances was also assessed, as were the frequency of side effects and independent patient dropout. The study also incorporated practical factors of the therapy, such as the route of administration, dosage regimen, and the drug’s patient convenience, which can have a significant impact on adherence to therapy. Results: Nalmefene, administered in an “as needed” regimen, demonstrated statistically significant activity in reducing HDD and total alcohol consumption (TAC) among patients with AUD, particularly those with elevated World Health Organization (WHO) DRL risk. Preliminary findings from the ESENSE1 (Efficacy of Nalmefene in Alcohol Dependence; the first phase III study), ESENSE 2 (Efficacy of Nalmefene in Alcohol Dependence, the second phase III study), and SENSE (the final phase III long term-safety and cost-effectiveness study) studies indicate a substantial decrease in HDD and TAC following the initial month of treatment. These effects persist throughout the subsequent follow-up period. Several Japanese studies have corroborated the effectiveness of Nalmefene, demonstrating its efficacy across both short-term and long-term applications. Furthermore, these studies have substantiated its safety profile, indicating that there is no inherent risk of addiction or the emergence of withdrawal symptoms. The mild nature of adverse events (most commonly nausea and dizziness) led to a relatively low discontinuation rate of Nalmefene treatment. A subsequent study, employing a recognized methodology, corroborated the efficacy of psychosocial support in enhancing treatment outcomes. Meta-analyses demonstrate that Naltrexone exhibits comparable efficacy in reducing the frequency and severity of alcohol consumption. In select populations, the injectable form (LAI) of this pharmaceutical agent facilitates less frequent dosing, which is advantageous for the treatment process. A comparison of Nalmefene and Naltrexone reveals that the latter does not demonstrate a significant impact on the likelihood of individuals returning to heavy alcohol consumption. Conclusions: In the treatment of AUD, both naltrexone and nalmefene have been shown to yield positive outcomes, particularly in terms of reducing the HDD and TAC. According to the World Health Organization (WHO) classification, Nalmefene is indicated for individuals with a high risk of developing serious conditions. It has been demonstrated to produce rapid and sustained results while exhibiting a favorable safety profile, characterized by the absence of significant adverse effects. Naltrexone is a medication that has proven to be effective. LAI may have a positive impact on the efficacy of treatment. Full article

Exchange-rate forecasting requires modelling non-stationary dynamics, heavy-tailed shocks, and complex temporal dependencies. However, forecasting performance in emerging-market currencies is fundamentally constrained by intrinsic dynamical instability, while most existing approaches are evaluated primarily through predictive accuracy rather than the predictability limits of the underlying system. This paper develops a predictability-aware framework that combines nonlinear dynamical diagnostics with a Lévy-driven neural stochastic differential equation model. Drift and diffusion are parameterized by neural networks and driven by $\alpha$-stable Lévy motion, enabling the representation of non-Gaussian fluctuations, abrupt shocks, and regime changes. To learn under discontinuous dynamics, we introduce a structurally constrained training objective based on a strong-form discretization of the underlying SDE. To characterise intrinsic predictability, we employ phase-space reconstruction and maximal Lyapunov exponent estimation. These diagnostics are interpreted as finite-sample measures of trajectory divergence and effective instability in a stochastic system, rather than evidence of low-dimensional deterministic chaos—a distinction motivated by well-documented limitations of chaos testing in financial data. Experiments on multiple West African currency pairs demonstrate competitive short-horizon forecasting performance relative to econometric and neural baselines while providing a principled framework for analysing predictability degradation under heavy-tailed stochastic dynamics. Across currencies and model classes, forecasting accuracy deteriorates beyond horizons comparable to the estimated Lyapunov time, suggesting that forecast degradation reflects intrinsic dynamical instability rather than model-specific limitations. The results support the view that reliable exchange-rate prediction is fundamentally a short-horizon problem and illustrate how stochastic dynamical modelling and predictability diagnostics can be combined to characterise forecasting limits in heavy-tailed financial systems. Full article

Slope stability in open-pit mining is not a static condition but evolves continuously as excavation progresses and geomechanical conditions change. In this study, an integrated approach combining ground-based radar monitoring, satellite-based InSAR time-series analysis, and numerical stability modeling was applied to evaluate slope behavior in a large-scale open-pit copper mine with complex geological and structural characteristics. Radar data revealed progressive and episodic deformation concentrated in specific slope sectors, while InSAR observations showed that deformation continued at lower rates after the main movement phase, providing a longer-term perspective of slope response. Stability analyses using limit equilibrium and finite element methods indicate that the slope operates close to a limit equilibrium condition, particularly under saturated scenarios where factors of safety approach critical levels and strain localization becomes more pronounced. The results show a clear link between observed deformation patterns and calculated stability conditions, with structural discontinuities and groundwater playing a dominant role in controlling slope behavior. Based on these findings, an integrated workflow is proposed that links monitoring data with stability assessment, enabling the identification of critical zones and supporting the evaluation of slope conditions during ongoing mining operations. This approach contributes to more reliable decision-making and supports safer and more sustainable open-pit mining practices. Full article

Raman spectroscopic analysis of fluorite was conducted in a diamond anvil cell (DAC) over a pressure range of 0.5–20.5 GPa under different hydrostatic environments, whereas the electrical conductivity was measured at 298–873 K and 1.2–19.6 GPa. High-resolution transmission electron microscopy (HRTEM) observations were performed on both the initial and recovered samples after recovery to ambient conditions. Three representative pressure-transmitting media (PTMs), including silicone oil, the mixture of methanol and ethanol (4:1 volume ratio, ME), and helium, were employed to control the degree of hydrostaticity within the DAC sample chamber. Experimental results indicate that the pressure-induced abrupt change in A_1g, A_3g, B_1g and B_2g Raman modes, together with the discontinuities in pressure-dependent Raman shifts, Grüneisen parameters, and electrical conductivity, can efficiently characterize the α (cubic structure, space group $Fm\overline{3}m$, No 225)-to-γ (cotunnite structure, PbCl₂-type, space group Pnma, No 62) phase transition in fluorite. The transition pressures are determined to be 10.4, 9.6, 8.9 and 7.5 GPa under conditions of no PTM, silicone oil, ME and helium, respectively, demonstrating that the structural phase transition of fluorite is highly sensitive to hydrostaticity. Raman spectroscopy and electrical conductivity measurements upon decompression reveal that the phase transition is reversible, which is further confirmed by the HRTEM microstructural observation on both the initial and recovered samples. The linear relationships between electrical current and sinusoidal voltage, with the nonlinearity factors close to 1.00, manifest the Ohmic response of fluorite under high pressure. Finally, our high-temperature and high-pressure electrical conductivity results revealed the negative dependence of transition temperature on pressure, and the phase boundary between cubic and PbCl₂-type fluorite was determined as: P (GPa) = 13.057 (±1.008) − 0.008 (±0.001) T (K). The obtained phase diagram of fluorite can be employed to deeply explore the high-pressure phase stability and structural transitions of other similar binary halide family minerals. Full article

Background: 5q spinal muscular atrophy (SMA) is a hereditary neuromuscular disorder characterized by progressive muscle weakness. Nusinersen, the first disease-modifying therapy for SMA, has demonstrated efficacy in both clinical trials and real-world studies. However, the precise timing of therapeutic onset following Nusinersen administration remains unclear. Methods: This retrospective study analyzed clinical data from patients with genetically confirmed 5q SMA who received Nusinersen treatment for at least six months at Peking University First Hospital. Motor function was assessed using standardized scales prior to each dose. Results: In total, 74 patients were screened, of whom 62 were enrolled, including 14 with type 1, 29 with type 2, and 19 with type 3 SMA. Thirty-two patients completed motor function assessments. After six months of treatment, 62.5% achieved a primary clinically meaningful response (an increase of ≥4 points in CHOP-INTEND or ≥3 points in HFMSE). Seven patients (21.9%) attained or regained motor milestones. Median improvements were 6 points in CHOP-INTEND (p = 0.001), 4 points in HFMSE (p = 0.003), and 1.5 points in RULM (p = 0.045). Further analysis indicated that the available median time to treatment response was approximately 2 months. In patients with severe scoliosis or prior spinal surgery, ultrasound-guided lumbar puncture demonstrated a high success rate (94.9%). Regarding safety, intrathecal injection-related adverse events occurred in eight patients (12.9%), and no adverse events led to treatment discontinuation. Conclusions: During the loading phase, Nusinersen provides clinical benefit for the majority of patients, with a median time to therapeutic response for monitoring of approximately 2 months. Ultrasound-guided intrathecal administration is the preferred approach for individuals with complicated spinal conditions. These findings may help guide clinical expectations for physicians, patients, and caregivers. Full article

Background: A previous short-term retrospective analysis from our center suggested early improvement in pain, function, and sleep outcomes after fixed-dose tramadol/paracetamol therapy in patients with early-stage symptomatic knee osteoarthritis (KOA). However, the durability of these outcomes beyond the initial treatment phase remains insufficiently described in routine clinical practice. Objective: To describe short- and mid-term patient-reported outcomes and safety during extended follow-up in adults with symptomatic KOA treated with fixed-dose tramadol/paracetamol in routine outpatient care. Methods: This single-center retrospective observational extension study analyzed a fixed cohort of 30 adults with symptomatic knee osteoarthritis and Kellgren–Lawrence grade I–II treated with fixed-dose tramadol/paracetamol in routine outpatient care. Patients were evaluated at baseline (T0), 15 days (D15), 3 months (M3), and 6 months (M6), where evaluable follow-up data were available. The primary outcome was change in pain intensity measured by the Numeric Rating Scale (NRS). Secondary outcomes included WOMAC total and subscale scores, Pittsburgh Sleep Quality Index (PSQI) score, adverse events, and treatment discontinuation. Results: Patients had a mean age of 64.8 ± 9.6 years and a mean BMI of 27.3 ± 5.0 kg/m². NRS pain improved from a median of 6.0 (5.0–7.0) at baseline to 4.0 (2.0–5.3) at D15 and 3.0 (2.0–5.0) at both M3 and M6. WOMAC total score improved from 47.8 ± 12.8 at baseline to 35.6 ± 13.8 at D15, 33.8 ± 13.6 at M3, and 33.9 ± 13.5 at M6. Sleep score improved from 9.5 (7.0–15.0) at baseline to 7.0 (5.0–9.0) at D15 and remained improved at M3 and M6. Mild adverse events were reported in 10.0% of patients, and discontinuation occurred in 6.7%. Conclusions: In this small, uncontrolled, single-center retrospective cohort of adults with early-stage symptomatic KOA, fixed-dose tramadol/paracetamol was associated with early improvement in pain, WOMAC outcomes, and sleep, with group-level benefits remaining evident through 6 months. These findings should be considered exploratory and hypothesis-generating rather than comparative evidence of effectiveness. Larger controlled studies are needed to confirm durability, comparative benefit, and long-term safety. Full article

Clay mineral authigenesis and transformation are key diagenetic processes that influence the evolution of sandstone reservoir quality. Although smectite formation and its transformation to illite have been widely studied in clay-rich and feldspathic systems, their development in highly quartz-rich sands remains less well constrained. This study investigates the experimental formation of authigenic smectite and its subsequent illitization in a quartz-dominated sand under controlled hydrothermal experiments. Quartz-rich glass sand from the Middle Jurassic Mariedal Formation (Skåne, Sweden) was reacted with natural Red Sea water in sealed reactors at 80, 150, 200, and 250 °C for 14 days to simulate progressive burial diagenesis. Mineralogical, textural, and geochemical changes were evaluated using thin-section petrography, SEM-EDS, WD-XRF, XRD, and ICP-OES. The starting material is composed predominantly of quartz (91.3%), with minor K-feldspar (6.2%) and muscovite (1.4%), providing limited but sufficient reactive components for clay mineral formation. Dissolution of K-feldspar and muscovite began at 80 °C and continued throughout the experiments. Authigenic smectite was first detected at 150 °C as discontinuous grain-coating phases, indicating nucleation through dissolution–precipitation reactions linked to feldspar alteration and uptake of Mg from the reacting fluid. At 200 °C, the smectite coating became thicker and more extensive, with the onset of transformation to illite through mixed layer stages. By 250 °C, illite becomes the dominant clay mineral, recording progressive smectite illitization with increasing temperature. Fluid chemistry shows systematic variations with temperature, including decreasing Mg and evolving K concentrations, reflecting progressive mass transfer between solid and fluid phases. These results demonstrate that even highly quartz-rich sands can generate authigenic clay minerals when minor reactive phases and suitable fluid chemistry are present. The experiments provide a process-based analogue for clay mineral evolution in quartz-rich sandstone reservoirs and highlight the importance of coupled mineral–fluid reactions during burial diagenesis. Full article

Collision detection is the core of collision analysis which is a vital fundamental work in computational particle mechanics. Collision detection algorithms can be divided into direct and indirect algorithms. Among them, the indirect algorithms transform the collision detection between two 2D objects into the position judgment of a reference point and a 2D object by constructing the no-fit polygon (NFP). However, the existing NFP algorithms are either not suitable for concave objects, or their time complexity is too high. This has hindered the development of indirect algorithms. Almost unknown to researchers interested in NFP, in the field of discontinuous mechanics calculation, there exists an ‘entrance block’ in Contact theory. Since NFP is the outline of the entrance block, the entrance block also has the potential to develop into a collision detection algorithm like NFP. The entrance block is suitable for arbitrary objects but ignores the rotation in each time step, which restricts it from becoming a collision detection algorithm. In this study, we improve this limitation and propose a 2D collision detection algorithm that is suitable for arbitrary objects. This algorithm can distinguish collision and contact, which reduces the calculation of late collision response. In addition, the algorithm has the potential to be transformed into a continuous algorithm and a new narrow-phase 3D collision detection algorithm. Finally, we propose a potential NFP algorithm that can be applied to arbitrary objects, which has an important influence on many NFP-related fields like computer graphics, operations research, computational mechanics, etc. Full article

An emotional neural network-based global predefined-time sliding mode control (ENN-GPTSMC) method is proposed for an uncertain hybrid mechanism. To estimate and compensate for the lumped uncertainty including discontinuous friction, an emotional neural network is developed. Simultaneously, a predefined-time terminal sliding mode control (PTTSMC) uses the estimation value. The adjustable predefined-time performance parameters are then incorporated into the PTTSMC law to extend its attractiveness for the system states to the global domain, thereby solving the limitation of the existing PTTSMC that can only locally achieve the predefined-time convergence of the system states during the reaching phase. The fast convergence of system states is subsequently achieved by embedding an integer-power linear term and its derivative into the sliding manifold and PTTSMC law, respectively. Based on these, an ENN-GPTSMC algorithm is designed. Furthermore, the saturation function of a dynamic boundary layer with an adjustable thickness is designed to avoid the singularity of ENN-GPTSMC, thereby achieving no-singularity fast global predefined-time convergence of the system. Theoretical analysis shows the Lyapunov stability of the system. Finally, simulation and prototype experiments are used to verify the effectiveness of the proposed method. Full article