Point Method Research Articles

Novel Approach to Optimizing Express-Local Metro Train Timetable Considering Multiple Train Stopping Patterns

A traditional hybrid operational mode of a metro system usually combines the express and local trains. The stopping patterns of express trains are generally assumed to be the same. To provide a diverse service, this paper aims to explore the train timetable optimization method when the express trains have different stopping patterns. A passenger-oriented timetabling model for reducing passenger waiting time is established, which is proved to be a quadratic programming problem. Then, an Interior Point Method is applied to obtain the best timetable. A case study based on the Guangzhou Metro Network is conducted, symbolizing different operation strategies. The results indicate that the proposed model can efficiently reduce the passenger waiting time by 16.8% and the number of stranded passengers by 15.9%. The practical implications of this research are significant, as it introduces a new approach to train timetable optimization that can be applied to real-world metro systems.

Convergence of the preconditioned proximal point method and Douglas–Rachford splitting in the absence of monotonicity

Convergence of the preconditioned proximal point method and Douglas–Rachford splitting in the absence of monotonicity

Clinical features, procalcitonin concentration, and bacterial infection in febrile hospitalized cancer patients: a descriptive study and association analysis.

Fever in cancer patients can occur for reasons other than bacterial infections. Without practical tools to distinguish actual infections, treatment delays may occur, reducing effectiveness and increasing antibiotic resistance. This study aimed to identify clinical features and procalcitonin (PCT) levels as indicators of bacterial infection in fevers among cancer patients. This retrospective study enrolled 225 patients with cancer and fever at the Maharat Nakhon Ratchasima Hospital. Data on the clinical characteristics, laboratory results, and bacterial cultures were collected. Associations were analyzed using logistic regression, and the appropriate PCT cutoff point was determined using ROC analysis. Of 225 cancer patients with fever, 54 (24%) had positive bacterial cultures, with Klebsiella pneumoniae being the most common pathogen. Significant clinical features included age (OR 1.06, 95% CI 1.01-1.12), increased heart rate (OR 1.05, 95% CI 1.02-1.08), and localizing symptoms (OR 7.62, 95% CI 2.49-22.70). Key laboratory findings were absolute neutrophil count (OR 1.15, 95% CI 1.03-1.28) and PCT level (OR 1.39, 95% CI 1.07-1.80). Appropriate PCT cutoff points for predicting bacterial infection were analyzed using various methods, resulting in values of 1.045, 0.546, 0.546, and 0.4025ng/ml. The concordance probability and closest to the point (0,1) methods suggested a rounded cutoff point of 0.5ng/ml, which provided a sensitivity of 61% and a specificity of 78%. The AUC for PCT was 0.731, indicating moderate accuracy. Procalcitonin, in conjunction with clinical features, may be used to classify the cause of fever in cancer patients. Therefore, a clinically predictive model would be useful.

Optimal Beamforming for Covert Communication in MIMO Relay Systems

ABSTRACTThis paper investigates the optimal beamforming design for covert communication in a multiple‐input multiple‐output (MIMO) relay system consisting of source, destination, relay and warden. For both scenarios when each transmitting node knows the perfect or partial warden's channel state information (CSI), we first develop theoretical models to depict the inherent relationship between the beamforming matrices at source/relay and end‐to‐end covert performance of the system regard the minimum detection error probability and covert capacity. Based on these models, we then formulate the optimal beamforming for covert capacity maximization under perfect and partial CSI as linear non‐convex (LNC) and non‐linear non‐convex (NLNC) optimization problems, respectively. We then apply Lagrangian and Hadamard inequality methods to solve the LNC optimization problem to determine the closed‐form expressions for the optimal beamforming matrices at source/relay, based on which a stochastic gradient descent algorithm is developed to evaluate the maximum covert capacity. For the complicated NLNC problem, we propose an efficient search algorithm based on S‐procedure lemma and interior point methods to identify the optimal beamforming matrices to reach the maximum covert capacity. Finally, we provide extensive numerical results to illustrate the covert performance enhancement from adopting the optimal beamforming in MIMO relay systems.

Mathematical modeling of water sorption isotherms in specialty coffee beans processed by wet and semidry postharvest methods

This study investigates the experimental assessment and mathematical modeling of the water sorption isotherms in dried specialty coffee beans processed by wet and semidry postharvest methods. The wet and semidry sorption isotherms were experimentally obtained over a range of water activities between 0.1 and 0.85 at temperatures of 25, 35, and 45 °C using the dynamic dew point method (DDI). Mathematical modeling was conducted to describe the influence of water activity, temperature, and postharvest method on the equilibrium moisture content. Twelve conventional sorption equations and four machine learning techniques were employed for modeling, using 75% of the experimental data for training and 25% for validation. The selection of the best model was carried out via multifactor Analysis of Variance (ANOVA). Experimental results showed that wet and semidry coffee beans exhibited a type II S-shaped isotherm (Brunauer–Emmett–Teller classification) and a significant (p < 0.05) influence of temperature on sorption curves. Additionally, the mucilaginous coating found in semidry coffee beans provided a protective role against water sorption. The Support Vector Machine (SVM) model provided the best fit for describing the sorption isotherms (mean relative error, MRE < 1% and adjusted coefficient of determination, R2adj > 99%), demonstrating its robustness in predicting the equilibrium moisture content as a function of water activity, temperature, and postharvest processing method. This mathematical model could serve as a virtual representation of the storage process, facilitating real-time decision-making to enhance coffee quality management during storage.

Hyperstability of Functional Equation Deriving from Quintic Mapping in Banach Space by Fixed Point Method

Hyperstability of Functional Equation Deriving from Quintic Mapping in Banach Space by Fixed Point Method

579. Safety and Immunogenicity of Mpox Vaccination in Adolescents

Abstract Background Monkeypox (Mpox) is a global public health threat. In the current Democratic Republic of Congo (DRC) mpox outbreak, children &amp;lt; 15 years of age comprise 70% of cases and 88% of deaths. Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccine is a live attenuated, non-replicating orthopoxvirus vaccine licensed in the US to prevent smallpox and mpox. MVA-BN is not approved in persons &amp;lt; 18 years of age (though is available in some countries under emergency use authorization). Geometric Mean Titers of Vaccinia-Specific PRNT by Time Point and Age Group Methods We conducted a Phase 2, open-label, multisite clinical trial to evaluate the safety and immunogenicity of two 1x108 TCID50 doses of MVA-BN vaccine administered subcutaneously 28 days apart in adolescents aged 12-17 years compared to adults aged 18-50 years (NCT05740982). A planned interim analysis evaluated safety through Day 210 (180 days post dose 2) and immunogenicity through Day 43 (14 days post dose 2). Results Three hundred fifteen adolescents (161 [51%] aged 12-14 years, 160 [51%] male, 216 [69%] white, 251 [80%] not Hispanic or Latino) were compared to 211 adults (94 [45%] male, 145 [69%] white, 149 [71%] not Hispanic or Latino). Solicited systemic and local events, and unsolicited adverse events (AEs), were similar in both groups. Dizziness was more common in adolescents (9 events in 8/315 (3%) versus none in adults) but similar to rates reported after other adolescent vaccines. Overall, MVA-BN was well tolerated. Day 43 antibody responses, based on vaccinia virus (Western Reserve strain) plaque-reduction neutralization titer (PRNT) assay geometric mean titer (GMT), elicited by MVA-BN in adolescents (470.3 [95% CI: 422.3, 523.8]) were non-inferior to the response in adults (293.2 [95% CI: 249.8, 344.2]); GMT ratio: 1.60 [95% CI: 1.32, 1.95]) (Figure). Conclusion The interim data demonstrate MVA-BN vaccine is well-tolerated and the peak GMT met prespecified non-inferiority criteria for adolescents as compared to adults. These findings are relevant to adolescents in the US and in areas where Mpox is endemic. Evaluations in younger children are urgently needed to extend protection to those who are most vulnerable. Disclosures C. Mary Healy, MD, FIDSA, Dexcom Inc: Stocks/Bonds (Public Company)|Hillevax, Inc: Member of Advisory board|Intuitive Surgical Inc: Stocks/Bonds (Public Company)|Quidel Corporation: Stocks/Bonds (Public Company)|Vapotherm: Stocks/Bonds (Public Company) C. Buddy Creech, MD, MPH, CommenseBio: Advisor/Consultant|GSK: Advisor/Consultant|Moderna: Advisor/Consultant|Moderna: Grant/Research Support|TDCowen: Advisor/Consultant|UpToDate: Honoraria|Vedanta: Grant/Research Support Sharon E. Frey, MD, Bavarian Nordic: Grant/Research Support|Saint Louis University (SLU): Grant/Research Support

Effect of ply structure on thermal residual stress in 3D needle-punched C/SiC composites

Three-dimensional needle-punched (3DNP) carbon fiber-reinforced silicon carbide (C/SiC) composites possess better mechanical properties and lower cost than two-dimensional plain-woven (2DPW) or three-dimensional braided (3DB) C/SiC composites. For 3DNP C/SiC composite, the composite’s internal thermal residual stress (TRS) affects the mechanical properties and damage mechanisms, for example, initial matrix cracking, fiber/matrix (F/M) interface debonding, fibers fracture and pullout under the mechanical loading. In this paper, the effect of ply structure on the TRS of 3DNP C/SiC composites with different ply structures was investigated. Cyclic loading/unloading tensile tests at different tensile peak stresses were conducted to obtain the mechanical hysteresis loops. The composite’s thermal residual strain, peak strain, and tangent modulus with increasing peak stresses were calculated through the hysteresis loops and used to derive the thermal residual stress and strain using the common intersection point (CIP) method. Relationships between the composite’s ply structures, mechanical hysteresis loops, thermal residual stress/strain, and internal damage state were established. The analysis can better help the engineering designers reduce the thermal residual stress by adjusting the composite’s ply structures.

Development of a Peltier-based chilled-mirror hygrometer, SKYDEW, for tropospheric and lower-stratospheric water vapor measurements

Abstract. We have developed a Peltier-based non-cryogenic chilled-mirror hygrometer named SKYDEW to measure water vapor from the surface to the stratosphere. Several chamber experiments were conducted to investigate the characteristics and performance of the instrument under various conditions. The stability of the feedback controller that maintains the condensate on the mirror depends on the controller setting, the condensate condition, and the frost point in ambient air. The results of condensate observation by a microscope and proportional-integral-derivative (PID) tuning in a chamber were used to determine the PID parameters of the controller such that slight oscillations of the scattered light signal from the mirror and mirror temperature are retained. This allows for the detection of steep gradients in the humidity profile, which are otherwise not detected because of the slower response. The oscillation of the raw mirror temperature is smoothed with a golden point method that selects the equilibrium point of the frost layer. We further describe the details of the data processing and the uncertainty estimation for SKYDEW measurements in terms of the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) requirements. The calibration uncertainty of the mirror temperature measurement is &lt; 0.1 K for the entire temperature range from −95 to 40 °C. The total measurement uncertainty of SKYDEW measurements can exceed 0.5 K in regions where large oscillations of the mirror temperature remain. Intercomparisons with relative humidity (RH) sensors on radiosondes, the cryogenic frost point hygrometer (CFH), and the Aura Microwave Limb Sounder (MLS) were performed at various latitudes in the Northern Hemisphere to evaluate the performance of SKYDEW. These results show that SKYDEW can reliably measure atmospheric water vapor up to 25 km altitude. Data from several SKYDEW and CFH measurements predominantly agree within their respective uncertainties, although a systematic difference of ∼ 0.5 K between SKYDEW and CFH was found in the stratosphere, the reason for which is unknown. SKYDEW shows good agreement with Aura MLS for profiles that are not affected by contamination.

Stability of a generalized Drygas functional equation via Brzdȩk’s fixed point method

Stability of a generalized Drygas functional equation via Brzdȩk’s fixed point method

Implicit Bonded Discrete Element Method with Manifold Optimization

This article proposes a novel simulation approach that combines implicit integration with the Bonded Discrete Element Method (BDEM) to achieve faster, more stable, and more accurate fracture simulation. The new method leverages the efficiency of implicit schemes in dynamic simulation and the versatility of BDEM in fracture modeling. Specifically, an optimization-based integrator for BDEM is introduced and combined with a manifold optimization approach to accelerate the solution process of the quaternion-constrained system. Our comparative experiments indicate that our method offers better scale consistency and more realistic collision effects than finite element method and material point method fragmentation approaches. Additionally, our method achieves a computational speedup of 2.1 to 9.8 times over explicit BDEM methods.

Shear Wave Elastography Evaluation of Testicular Stiffness in Dogs Affected by Testicular Pathology

Shear wave elastography (SWE) is an advanced ultrasound technique that assesses tissue stiffness by measuring shear wave speed (SWS) produced after an acoustic impulse. It includes bidimensional (2D-SWE) and focal point (pSWE) methods, allowing qualitative and quantitative analysis of tissue stiffness. This study aimed to describe the elastographic features of testicular abnormalities in dogs, supported by histological findings. Eighteen dogs with testicular abnormalities underwent B-mode ultrasound, power and color Doppler ultrasound, 2D-SWE, and pSWE before orchiectomy. Five cryptorchid testes were excluded and thirty-one testes (12 normal, 7 with leydigomas, 6 with seminomas, 1 with a round cell tumor, and 5 with orchitis) were examined. Normal testes, lesions, and adjacent healthy tissues (no evident ultrasound changes, NEUC) were sampled. Testicular abnormalities presented SWS values of 1.05–4.89 m/s (2D-SWE) and 1.35–5.31 m/s (pSWE). Significant differences were observed among normal testes, NEUC areas, and those with orchitis, leydigomas, and seminomas by both 2D-SWE and pSWE. Normal testes were significantly softer than ones with leydigomas, seminomas, and orchitis, and NEUC areas also had different SWS values compared to those with tumors and orchitis (p &lt; 0.05). However, SWE techniques lacked specificity in differentiating between orchitis and tumors. Diagnostic accuracy of SWE techniques for testicular lesions remains challenging and requires further investigation to fully address its clinical potential.

Quantitative Review of Critical Plane Criteria and Stress Analysis Approaches for Multiaxial Fatigue of Welded Joints

ABSTRACTThis quantitative review evaluates the effectiveness of stress‐based critical plane criteria, specifically Findley's criterion, the approach due to Carpinteri–Spagnoli (CS), and the Modified Wöhler Curve Method (MWCM), in assessing fatigue strength in aluminum and steel welded joints subjected to constant amplitude (CA) and variable amplitude (VA) multiaxial loading. These criteria were analyzed alongside stress analysis approaches, including nominal stress (NS), hot‐spot stress (HSS), effective notch stress (ENS), and the Theory of Critical Distances–Point Method (TCD PM). Results confirm that all criteria effectively estimate fatigue life for steel welded joints under CA loading, with MWCM combined with HSS proving most accurate. For aluminum joints, estimations showed greater conservatism and scatter, highlighting the need for further experimental data to improve accuracy. Experimentally calibrated constants significantly enhanced prediction reliability. Future research should refine these criteria for diverse aluminum grades and thicknesses, ensuring accurate estimations and robust alternatives to established codes.

Modeling of flows under dams using the method of singular points

Today, the relevance of issues related to regular and safe water supply for human beings, society and the economy is beyond doubt. One of the main ways to store and man age water resources is the construction and operation of dams. The most important task of sustainable existence and development of reservoir projects is dam safety. To ensure this, theoretical research, creation of mathematical and computer models of the physical phe nomena and engineering structures under study are necessary. The paper proposes methods for constructing flows in the middle sections of a dam with a linear filtration law by ap propriately placing special flow points and applying conformal transformations. Filtration f lows with different outlines of impermeable floodplain, flows under a dam with filters in homogeneously isotropic and heterogeneously anisotropic soils are considered.

On the Boundary Conditions in Out-of-Plane Analysis of Thin Plates by the Finite Point Method

The finite point method (FPM) is a numerical, mesh-free technique for solving differential equations, particularly in fluid dynamics. While the FPM has been previously applied in solid mechanics to analyze plates under in-plane loading, there remains a notable scarcity of research exploring the out-of-plane analysis of elastic plates using this method. This study thoroughly investigates the elastic FPM analysis of thin plates subjected to transverse loadings, focusing specifically on various boundary conditions (BCs). Boundary conditions represent a significant challenge in the out-of-plane analysis of thin plates within the FPM framework. To address this challenge, the approach incorporates additional nodal points positioned close to each boundary node, supplementing the points distributed throughout the plate’s interior and along its edges. The strong form of the governing equation is employed for the interior points, while the analysis also includes the scenario of a plate resting on boundary columns. Both distributed and concentrated external loads are examined to provide a comprehensive understanding of the behavior under different loading conditions. Furthermore, the optimal placement of the extra boundary nodes is briefly discussed, alongside a focus on the number of nodes within the finite point clouds. An appropriate range for this number is proposed, although the determination of the optimal distance for the extra boundary nodes and the ideal number of cloud points is earmarked for future research. The contribution of this work is to enhance the understanding of the FPM in the context of thin plates, particularly concerning the critical influence of boundary conditions.

Toward engineering lattice structures with the material point method (MPM)

Toward engineering lattice structures with the material point method (MPM)

The pinball contact algorithm for the material point method

The pinball contact algorithm for the material point method

Generalization of the location method of ashi points

Through analyzing the every textual research literature on the origin of the location method of ashi points, it is pointed out that the location method of ashi points has been generalized. It is known through systematic research and theoretical identification that this method refers to the simple way to locate the points, originated from the folk, and it is widely used to find the sites for pain relief when compared to the official education of meridians and acupoints, as well as treatment. At the time with the shortage of medical services and supplies, the poor people had no alternative, which results in a certain limitation. Modern acupuncture practitioners must associate ashi points with the acupoints of fourteen meridians and the extraordinary points in clinical practice, and deepen the exploration with modern medical knowledge and technology adopted.

An Adaptive Voltage Reference-Based Multi-Objective Optimal Control Method for the Power Flow Symmetry of Multi-Terminal DC Systems with the Large-Scale Integration of Offshore Wind Farms

The optimization of the symmetry of MTDC systems after a contingency is crucial for the stable and economic operation of the MTDC systems. In this paper, a multi-objective optimal control method for the power flow symmetry of MTDC systems for the large-scale integration of offshore wind farms is proposed. A mirror relationship between the available headroom of DC lines and VSCs and their actual power flow distribution performance is established. A corresponding symmetry index is established for the MTDC network, and the multi-objective optimization problem is converted into a series of single-objective problems by the normal boundary intersection method, and solved by the original dyadic interior point method, so as to obtain the Pareto optimal solution with uniform distribution. The compromise optimal solution is decided according to the entropy weight double-basis point method, which provides decision-making guidance for the operators. The simulation results show that the normal boundary intersection method can solve the multi-objective dynamic optimal control problem of the VSC-HVDC system quickly and efficiently, and improve the symmetry of the power flow in an MTDC network.

UAV Data Collection Co-Registration: LiDAR and Photogrammetric Surveys for Coastal Monitoring

When georeferencing is a key point of coastal monitoring, it is crucial to understand how the type of data and object characteristics can affect the result of the registration procedure, and, above all, how to assess the reconstruction accuracy. For this reason, the goal of this work is to evaluate the performance of the iterative closest point (ICP) method for registering point clouds in coastal environments, using a single-epoch and multi-sensor survey of a coastal area (near the Bevano river mouth, Ravenna, Italy). The combination of multiple drone datasets (LiDAR and photogrammetric clouds) is performed via indirect georeferencing, using different executions of the ICP procedure. The ICP algorithm is affected by the differences in the vegetation reconstruction by the two sensors, which may lead to a rotation of the slave cloud. While the dissimilarities between the two clouds can be minimized, reducing their impact, the lack of object distinctiveness, typical of environmental objects, remains a problem that cannot be overcome. This work addresses the use of the ICP method for registering point clouds representative of coastal environments, with some limitations related to the required presence of stable areas between the clouds and the potential errors associated with featureless surfaces.