Extrapolation Research Articles

The High-Order ADI Difference Method and Extrapolation Method for Solving the Two-Dimensional Nonlinear Parabolic Evolution Equations

In this paper, the numerical solution for two-dimensional nonlinear parabolic equations is studied using an alternating-direction implicit (ADI) Crank–Nicolson (CN) difference scheme. Firstly, we use the CN format in the time direction, and then use the CN format in the space direction before discretizing the second-order center difference quotient. In addition, we strictly prove that the proposed ADI difference scheme has unique solvability and is unconditionally stable and convergent. The extrapolation method is further applied to improve the numerical solution accuracy. Finally, two numerical examples are given to verify our theoretical results.

Diversity and availability of edible caterpillar host plants in the Luki Biosphere Reserve landscape in the Democratic Republic of the Congo

Edible caterpillars are an important food and economic resource for rural African people. However, they are subject to a number of threats; in particular, their host plants are threatened. The Luki Biosphere Reserve landscape is a region of the Democratic Republic of Congo where the practice of eating caterpillars is a recent phenomenon; however, rural communities have reported their scarcity. This study assessed the diversity and availability of host plants of the edible caterpillars in the Luki Biosphere Reserve (LBR) landscape. Botanical inventories were conducted in eleven ha plots of each of the following habitats: forest, savannah, fallow, and inhabited areas, covering an area of 44 ha. The coverage-based rarefaction and extrapolation method and the iNEXT online software were used to calculate the true diversity of edible caterpillar host plants. The diameter structure of the edible caterpillar host plant species was assessed by counting the number of individuals in each diameter class. The results revealed that in the Luki Biosphere Reserve landscape, edible caterpillars rely on 15 main plant host species (Spondias mombin L., Petersianthus macrocarpus (P.Beauv.) Liben, Croton sylvaticus Hochst. ex Krauss, Hymenocardia acida Tul., Lannea welwitschii (Hiern) Engl., Macaranga spinosa Müll.Arg., Celtis mildbraedii Engl., Coelocaryon botryoïdes Vermoesen, Albizia gummifera (J.F.Gmel.) C. A. Sm, Bridelia atroviridis Müll.Arg, Ficus mucuso Welw. ex Ficalho, Funtumia elastica (P.Preuss) Stapf, Lannea welwitschii (Hiern) Engl., Milicia excelsa (Welw.) C.C. Berg., and Terminalia superba Engl. & Diels). The habitats exhibited low species diversity of the edible caterpillar host plants. Moreover, several of these species are becoming scarce or are locally threatened with extinction. The trend in the diametric structure is similar to species evolving in a disturbed environment.The results of this study suggest potential habitat instability linked to human activities that could lead to biodiversity loss and, thus, a decline in edible caterpillars in the LBR landscape. A better understanding of the unfavourable conditions that influence the nutritional support for the edible caterpillars would help promote appropriate strategies that can be applied in local development plans for community lands at a landscape scale.

Exploring the photosensitizing potential of Nanoliposome Loaded Improved Toluidine Blue O (NLITBO) Against Streptococcus mutans: An in-vitro feasibility study.

Streptococcus mutans is a major contributor to dental caries due to its ability to produce acid and survive in biofilms. Microbial resistance towards common antimicrobial agents like chlorhexidine and triclosan has shifted the research towards antimicrobial Photodynamic therapy (PDT). In this context, Toluidine Blue O (TBO) is being explored for its photosensitizing properties against Streptococcus mutans. There is a huge variation in the effective concentration of TBO among the current studies owing to the differences in source of and delivery system TBO as well as the time, power and energy densities of light. The primary objectives of this study are to encapsulate improved Toluidine Blue O (ITBO) in nanoliposomes (NLITBO), characterize it, and evaluate its antibacterial photosensitizing potential against Streptococcus mutans suspensions in vitro. ITBO was synthesised as per Indian patent (number -543908). NLITBO was prepared using the thin-film hydration method. Dynamic light scattering experiment determined the vesicle size, polydispersity index (PDI), and zeta potential. Surface features were characterized by Scanning and Transmission Electron microscopy. ITBO release from NLITBO was assessed using the extrapolation method. The antibacterial activity of the NLITBO was determined by evaluating the zone of inhibition (ZOI) in the Streptococcus mutans culture and comparing with 2% chlorhexidine gluconate. The minimum inhibitory concentration (MIC) of NLITBO as a photosensitizer with red light (wavelength 650nm, power density 0.1 W/cm2, energy density 9-9.1 J/ cm2, 90seconds time) was evaluated against Streptococcus mutans cells by colorimetric method in 96 well plate. Percentage drug loading, loading efficiency, yield percentage, vesicle size, PDI, Zeta potential of NLTBO was reported as 9.3±0.4%, 84.4±7.6%, 73.5%, 123.52 nm, 0.57, -39.54mV respectively. Clusters of uni-lamellar nanovesicles with smooth non-perforated surfaces were observed in SEM and TEM. The size of the vesicle was within 100 nm. At 24 hours, a cumulative 79.81% of ITBO was released from NLITBO. Mean ZOI and MIC of NLITBO (1 μg /ml) were found to be 0.7±0.2 mm, 0.6μg/ml respectively. We have synthesized and encapsulated improved Toluidine Blue O (ITBO) in nanoliposomes (NLITBO) and thoroughly characterized the formulation. The antibacterial efficacy of NLITBO without light was demonstrated by ZOI which is similar to 2% chlorhexidine gluconate. MIC of NLITBO as a photosensitiser along with the optimal light parameter was also proposed in this study. These findings suggested that NLITBO could serve as an effective alternative to conventional antibacterial treatments in managing Streptococcus mutans rich biofilms. It can have potential pharmaceutical application in oral health care.

Yield curve extrapolation with machine learning

Abstract Yield curve extrapolation to unobservable tenors is a key technique for the market-consistent valuation of actuarial liabilities required by Solvency II and forthcoming similar regulations. Since the regulatory method, the Smith–Wilson method, is inconsistent with observable yield curve dynamics, parsimonious parametric models, the Nelson–Siegel model and its extensions, are often used for yield curve extrapolation in risk management. However, it is difficult for the parsimonious parametric models to extrapolate yield curves without excessive volatility because of their limited ability to represent observed yield curves with a limited number of parameters. To extend the representational capabilities, we propose a novel yield curve extrapolation method using machine learning. Using the long short-term memory architecture, we achieve purely data-driven yield curve extrapolation with better generalization performance, stability, and consistency with observed yield curve dynamics than the previous parsimonious parametric models on US and Japanese yield curve data. In addition, our method has model interpretability using the backpropagation algorithm. The findings of this study prove that neural networks, which have recently received considerable attention in mortality forecasting, are useful for yield curve extrapolation, where they have not been used before.

Evaluation of the powering extrapolation of a ship with a gate rudder system, including ageing and fouling effects

This paper is based on the evaluation results of the calm water powering extrapolation of a 90-m general cargo vessel, originally built with a conventional rudder system (CRS) and later retrofitted with an innovative energy-saving device (ESD) known as the Gate Rudder System® (GRS), as part of the EU H2020 Project GATERS. The power estimation of the vessel was conducted using an adapted extrapolation procedure based on the scaled model tests of the vessel in a towing tank, validated by the three sets of sea trials. The first sea trial was performed when the ship was new, while the latter two were conducted during the project timeline, before and after the GRS retrofit. This paper aims to adapt the ITTC-78 power extrapolation method to predict the power performance of a ship retrofitted with the GRS for the first time in the maritime industry. Within this framework, the specific objectives of the paper are to describe and validate the proposed method using relevant power-speed data of the GATERS project target vessel (M/V ERGE) initially equipped with the CRS and later replaced by the retrofit GRS to achieve the project objective. Due to the real-world circumstances of retrofitting a 13-year-old ship with a novel energy-saving device, investigating the effects of ageing, hull roughness, and fouling has also become one of the key objectives of the paper. The findings demonstrate the ageing effect on the target ship's powering performance after retrofitting with GRS, highlighting the need for special consideration of power extrapolation alongside the hull fouling effects. The paper also demonstrates that the GRS is an emerging ESD, as a retrofit beside newly built ships with GRS, which improved the powering performance of the project target vessel, achieving a remarkable 25% power saving based on the comparative full-scale sea trials.

Impact of gut permeability on estimation of oral bioavailability for chemicals in commerce and the environment.

Performance of pharmacokinetic models developed using in vitro-to-in vivo extrapolation (IVIVE) methods may be improved by refining assumptions regarding fraction absorbed (Fabs) through the intestine, a component of oral bioavailability (Fbio). Although in vivo measures of Fabs are often unavailable for non-pharmaceuticals, in vitro measures of apparent permeability (Papp) using the Caco-2 cell line have been highly correlated with Fabs. We measured bidirectional Papp for over 400 non-pharmaceutical chemicals using the Caco-2 assay. A random forest quantitative structure-property relationship (QSPR) model was developed using these and peer-reviewed pharmaceutical data. Both Caco-2 data (R²=0.37) and the QSPR model (R²=0.29) were better at predicting human bioavailability compared to in vivo rat data (R²=0.23). After incorporation into a high throughput toxicokinetics (HTTK) framework for IVIVE, the Caco-2 data were used to estimate in vivo administered equivalent dose (AED) for bioactivity assessed in vitro, The HTTK-predicted plasma steady state concentrations (Css) for IVIVE were revised, with modest changes predicted for poorly absorbed chemicals. Experimental data were evaluated for sources of measurement uncertainty, which were then accounted for using the Monte Carlo method. Revised AEDs were subsequently compared with exposure estimates to evaluate effects on bioactivity:exposure ratios, a surrogate for risk. Only minor changes in the margin between chemical exposure and predicted bioactive doses were observed due to the preponderance of highly absorbed chemicals.

Determining Bandgaps in the Layered Group‐10 2D Transition Metal Dichalcogenide PtSe2

AbstractUnlike traditional group‐6 transition metal dichalcogenides (TMDs), group‐10 TMDs such as PtSe2 and PdTe2 possess highly tuneable indirect bandgaps, transitioning from semiconducting in the near‐infrared to semimetal behavior with a number of monolayers (MLs). This opens up the possibility of TMD‐based mid‐infrared and terahertz optoelectronics. Despite this large potential, the optical properties of such materials have shown an extremely large disparity between that predicted and measured. For example, simulations show that a few MLs is required for the semiconductor–semimetal transition, whilst tens of MLs is found experimentally. This is a result of widely used optical extrapolation methods to determine bandgaps, such as the Tauc plot approach, that are not adapted here owing to i) nearby direct transitions, ii) the material dimensionality and iii) large changes in the non‐parabolic bandstructure with MLs. Here, uniquely combining optical ellipsometry to determine the complex permittivity, terahertz time resolved spectroscopy for the complex conductivity and in‐depth density functional theory (DFT) simulations, it is shown that the optical properties and bandstructure can be determined reliably and demonstrate clearly that the semiconductor‐semimetal transition occurs for PtSe2 layers ≈5 MLs. The microscopic origins of the observed transitions and the crucial role of the Coulomb interaction for thin semiconducting layers, and that of interlayer van der Waals forces for multilayer semimetallic samples are also demonstrated. This work of combining complimentary experimental techniques and extensive simulations avoids the application of constrained extrapolation methods to determine the optical properties of group‐10 TMDs, and will be of importance for future mid‐infrared and terahertz applications.

Intermediality of Modern Art and Technologies of its Perception

The purpose of the article is to reveal the peculiarities of the manifestation of termediality in modern art in their influence on perceptual processes and to propose appropriate technologies for the perception of intermedial artistic phenomena. The research methodology is based on the concepts of media theory, communication theory, modern art theory and uses general scientific principles of interconnection, systematisation, and synergy. The purpose and objectives of the article necessitated the application of the method of extrapolation of heuristic algorithms of exact sciences to the heuristics of artistic phenomena with a view to practical methods of organising the perception of the intermediality of modern art by students of higher education. The use of the analytical method made it possible to identify the content and design resources of intermediality in its current development. The scientific novelty consists in projecting the properties of intermediality of modern art onto the technology of its perception in the process of university training. In the article, for the first time in domestic art history, the peculiarities of the manifestations of intermediality of modern art in connection with the communication of its recipients are understood. Conclusions. Intermediality is one of the main trends in the development of art, which consists in a kind of dialogue. From the point of view of perceptual processes, intermediality actualises the integrity of perception, which involves different sensory modalities. Intermediality in the modern artistic space outgrows the boundaries of the interaction of arts, connecting other spheres of culture and ensuring the inseparability of synthesised elements in creative practices different from traditional ones. Perception of intermedia modern art requires preparation, which should be carried out in the educational process. Effective technologies for perceiving the intermediality of modern art are interactive and intermedial.

Crystal Structure and Li-Fe Order in Synthetic Mg(2-2x)LixFe3+x(SiO4) Olivine Structure.

Olivines are naturally occurring silicates consisting of isolated (SiO4)4- tetrahedra linked through M1O6 and M2O6 octahedra. In this study, we report the structural and crystal-chemical characterization of synthetic olivine crystals containing up to 25% Li-Fe3+ synthesized using the flux growth technique. Based on site scattering, <M1-O> and <M2-O> mean bond lengths, and charge neutrality of the chemical formula, we found a perfect ordering of Li and Fe3+ at the two distinct M1 and M2 sites. Unrestrained linear extrapolation to a hypothetical isostructural LiFe3+(SiO4) composition aligns well with the tabulated ionic radii of Li and Fe3+. Comparison made with the isostructural LiSc(SiO4) reveals that the Li-centered M2O6 octahedron has a significant capacity to distort in order to accommodate structural stresses, due to the relatively weak Li-O bond, while still achieving a bond valence sum that closely matches the formal charge of Li+. This behavior suggests the potential feasibility of an extended Li + Fe3+ for 2 Mg coupled substitution within the olivine structure. The reported structure of the LiFe3+(SiO4) endmember in the literature, despite its apparent matching of cell dimensions and space group with olivine, exhibits extremely unconventional crystal chemical features, raising questions about its validity. Given the importance of the suitability of Li-insertion in LiFeSiO4 as electrodes in rechargeable Li-ion batteries, further studies are needed to investigate its crystal structure and crystal chemistry.

Primal-Dual Extrapolation Methods for Monotone Inclusions Under Local Lipschitz Continuity

In this paper, we consider a class of monotone inclusion (MI) problems of finding a zero of the sum of two monotone operators, in which one operator is maximal monotone, whereas the other is locally Lipschitz continuous. We propose primal-dual (PD) extrapolation methods to solve them using a point and operator extrapolation technique, whose parameters are chosen by a backtracking line search scheme. The proposed methods enjoy an operation complexity of [Formula: see text] and [Formula: see text], measured by the number of fundamental operations consisting only of evaluations of one operator and resolvent of the other operator, for finding an ε-residual solution of strongly and nonstrongly MI problems, respectively. The latter complexity significantly improves the previously best operation complexity [Formula: see text]. As a byproduct, complexity results of the primal-dual extrapolation methods are also obtained for finding an ε-KKT or ε-residual solution of convex conic optimization, conic constrained saddle point, and variational inequality problems under local Lipschitz continuity. We provide preliminary numerical results to demonstrate the performance of the proposed methods. Funding: This work was partially supported by the National Science Foundation [Grant IIS-2211491], the Office of Naval Research [Grant N00014-24-1-2702], and the Air Force Office of Scientific Research [Grant FA9550-24-1-0343].

Современные угрозы и обоснование изменений в регулировании экономической безопасности региона

The article considers the main approaches of the theory of economic security. The concepts of "ensuring economic security", "managing economic security", "regulating the economic security of the region" are studied. The impacts affecting the adaptive readiness of the regional economic security complex, reflected in the concepts of "threat", "risk", "factor", "challenge" are noted. The expediency of a multi-vector approach to the organization of regulatory impacts of state and municipal government bodies aimed at ensuring the economic security of the country's regions in the context of overcoming modern threats is determined. A thesis is formulated about the place of regulation of regional economic security as an integral link between the systemic federal level of national security and heterogeneous regions of the country. Using the example of Perm Krai, the dynamics of the main indicators of regional economic security and their relationship with similar indicators of the Volga Federal District and the Russian Federation are considered, and an assessment of existing trends is carried out. The analysis of the elaboration of regulatory and legal documents of the Perm Territory using the extrapolation method of processing official statistics information has established the insufficiency of the measures taken to improve strategic planning in the region in the context of taking into account changing factors and conditions of the external environment. Significant deviations of the achieved results in ensuring the economic security of the Perm Territory from the forecast values approved by the strategic planning documents have been revealed, in particular in achieving the planned indicators in the areas of industrial and environmental safety of the region. It is proposed to revise the content of regulatory documents with the corresponding budget and resource content for the timely adaptation of the region to modern threats and challenges. It is recommended to pay special attention to such areas of economic security of the Perm Territory as: technological sovereignty, investment security and environmental protection.

Extending the frequency range of ISO 717-2 - a look at options and issues

In 2019, the Norwegian Standard NS 8175, which defines requirements for sound insulation in Norwegian buildings, was revised to include low frequency spectrum adaption terms for new dwellings. This change affects the applicability of measurements of weighted improvement of impact sound insulation, delta Lw, as the spectrum for calculating delta Lw, given in ISO 717-2, is limited downwards to 100 Hz. For a floating floor construction, this means that floors with a resonance frequency well below 100 Hz, and correspondingly a relatively high delta Lw, will be overrated in the sense that the measured delta Lw will be unaffected by the poor low frequency performance of the floating floor. To properly address this increased focus on low frequencies, an extended range spectrum is needed. In the work leading to this paper, a selection of extended range values for the reference heavyweight floor have been suggested, starting with a linear extrapolation of the values given in ISO 717-2. Data from laboratory measurements of delta Lw for floating floors have then been used to investigate the suitability of the suggested values. The results are summarised and discussed in this paper.

Estimation of ground vibration emission increase with respect to velocity in high-speed railways

During the design of a new line, it is often necessary to estimate railway vibration emissions at a given future speed from experimental data in similar circumstances, but at a different speed. Future levels are usually estimated according to a logarithmic evolution law with respect to speed, a typical one being that in USA FTA Report nº0123 "Transit Noise and Vibration Impact Assessment Manual", a de facto standard in the sector. Also, it is known that for high-speed lines a drastic increase in vibrations is observed when railway speed is higher than the propagation speed of surface Rayleigh waves. This phenomenon, known as trans-Rayleigh boom, produces a sharp discontinuity in the evolution of vibration emissions. However, vibration levels observed in the vicinity of a high-speed line have shown values well above the prediction rule suggested in FTA Manual, which could not be explained by a trans-Rayleigh boom. A more accurate extrapolation method based on local rail roughness measurements is capable of producing improved predictions compared to FTA rule of thumb. This contribution shows the details of the method suggested, and the improvement in the prediction (with respect to FTA extrapolation law) obtained in the specific case of a high-speed railway.

Physics-informed Neural Network for Force-free Magnetic Field Extrapolation

In this paper, we propose a physics-informed neural network extrapolation method that leverages machine learning techniques to reconstruct coronal magnetic fields. We enhance the classical neural network structure by introducing the concept of a quasi-output layer to address the challenge of preserving physical constraints during the neural network extrapolation process. Furthermore, we employ second-order optimization methods for training the neural network, which are more efficient compared to the first-order optimization methods commonly used in classical machine learning. Our approach is evaluated on the widely recognized semi-analytical model proposed by Low and Lou. The results demonstrate that the deep learning method achieves high accuracy in reconstructing the semi-analytical model across multiple evaluation metrics. In addition, we validate the effectiveness of our method on the observed magnetogram of active region.

Comparative examinations of wind speed and energy extrapolation methods using remotely sensed data – A case study from Hungary

Exact knowledge of wind energy potential is a fundamental issue in wind energy utilization. The vertical changes in wind speeds, that is, the wind profile, have a predominant impact on the wind energy available at a location because the kinetic energy of moving air is proportional to the square of the wind speed. Roughness describes the resistance of a 3D surface to moving air. The exponent α of the power law of Hellmann and the roughness length (z0) are two parameters that describe the effects of the roughness of the surface on the wind profile. They can be used for the vertical extrapolation of wind speeds. The exponent α can be determined using multiple height level wind speed measurement data, whereas a reliable technique for the calculation of the roughness length requires detailed knowledge of the 3D geometry of the measurement site. In the present study, the exponent α was calculated based on SODAR wind speed measurements, while (z0) was determined using a combination of GIS and UAS-based aerial survey methods. Wind speeds measured at 50 m were extrapolated for height levels of 80, 90, 100, 110, and 120 m using dynamic power law exponent values. Wind power was determined using the power law (method V1), roughness length (method V2), frequency distribution (method W-RF), and gamma distribution (method W-G), and Windographer software was compared to the values calculated from the empirical (measured) wind speeds. A comparative statistical analysis of the datasets of the power law and roughness length methods on monthly/diurnal, annual/diurnal, and month/direction contexts showed no significant differences at all height levels. Differences can be detected in the distribution of the signs of the differences at heights of 80 and 120 m for the entire dataset. Underestimation was dominant with a significant frequency (over 70 %) in the case of both methods and heights. There were no significant differences between the wind power estimations provided by the different methods, and all the methods involved in the study underestimated the wind speeds and wind energy potential for each height level. Methods V1 and V2 can be used alternatively, depending on the input data available for analysis. The major advantage of method V2 is that it provides the same accuracy as V1, which requires a UAS-based aerial survey at the beginning, but continuous wind measurements must be performed at a lower height only. This means that there is no need for a high measurement tower, which makes the measurements simpler, more cost-effective, and causes much less disturbance to the environment. Another important advantage of the methods presented here is that they use a dynamic approach of power law exponent values that provide a more realistic estimation of wind speed and energy on a diurnal scale.

Sand Production Prediction and Management Using a One-Dimensional Geomechanical Model: A Case Study in NahrUmr Formation, Subba Oil Field

Sand production in sandstone reservoirs is a complex problem for oil and gas companies. This problem can damage downhole equipment and surface production facilities. This paper presents a sand production case and quantifies sand risks for the NahrUmr formation located in Subbaoilfied.The risk of sanding or rock failure is commonly observed during production phases as well as drilling operations. A (1D) mechanical earth model was created using wireline log data and core data for estimating the formations mechanical properties.The extrapolation method is utilized for vertical stress prediction, whereas pore pressure and static Young’s modulus were calculated using Slowness Eaton method and John Fuller correlation respectively. The poro-elastic model was used to determine horizontal principal stresses and hydrocarbon intervals susceptible to sand production issues.The purpose of this study was achieved using Tech-Log software. Sand onset intervals are firstly predicted as an open hole using ten methods: Loading factor (LF), Critical drawdown pressure (CDDP), B-index, schlumberger (Sc), Elastic combination index (Ec-index), Interval Transit-Time (DTc), Total porosity method (PHIT), unconfined compressive strength (UCS), Shear modulus to bulk compressibility ratio (G/Cb), and shear failure method. Approximately ten methods refer to the same intervals that can produce sand. Secondly, sand depths were predicted by representing the well according to what actually existed as a cased hole by calculating the critical drawdown pressure (CDDP), which is calculated at various depletion rates (0%, 15%, 25%, and 35%) in order to measure the effect of reservoir pressure depletion on sand production. The results show that as the rock strength is increased, the amount of sand-free drawdown and depletion becomes larger. Also, a single-depth analysis was conducted for problem intervals, indicatg a sandwillproducefromdepth of 2527.7 m under certain conditions. Therefore, it is necessary to install sand control equipment in this well.

A lifetime economic model of mortality and secondary care use for patients discharged from hospital following acute stroke.

The long-term health-economic consequences of acute stroke are typically extrapolated from short-term outcomes observed in different studies, using models based on assumptions about longer-term morbidity and mortality. Inconsistency in these assumptions and the methods of extrapolation can create difficulties when comparing estimates of life-time cost-effectiveness of stroke care interventions. To develop a long-term model consisting of a set of equations to estimate the life-time effects of stroke care interventions to promote consistency in extrapolation of short-term outcomes. Data about further admissions and mortality was provided for acute stroke patients discharged between 2013 and 2014 from a large English service. This was combined with data from UK life tables to create a set of parametric equations in a model that use age, sex, and modified Rankin Scores to predict the life-time risk of mortality and secondary care resource utilisation including ED attendances, non-elective admissions, and elective admissions. A cohort of 1,509 (male 51%; mean age 74) stroke patients had median follow-up of seven years and represented 7,111 post-discharge patient years. A logistic model estimated mortality within twelve months of discharge and a Gompertz model was used over the remainder of the lifetime. Hospital attendances were modelled using a Weibull distribution. Non-elective and elective bed days were both modelled using a log-logistic distribution. Mortality risk increased with age, dependency, and male sex. Although the overall pattern was similar for resource utilisation, there were different variations according to dependency and gender for ED attendances and non-elective/elective admissions. For example, 65-year-old women with a discharge mRS of 1 would gain an extra 6.75 life years compared to 65-year-old women with a discharge mRS of 3. Over their lifetime, 65-year-old women with a discharge mRS of 1 would experience 0.09 less ED attendances, 2.12 less non-elective bed days and 1.28 additional elective bed days than 65-year-old women with a discharge mRS of 3. Using long-term follow-up publicly available data from a large clinical cohort, this new model promotes standardised extrapolation of key outcomes over the life course, and potentially can improve the real-world accuracy and comparison of long-term cost-effectiveness estimates for stroke care interventions. Data is available upon reasonable request from third parties.

High-Precision Forward Modeling of Controlled Source Electromagnetic Method Based on Weighted Average Extrapolation Method

High-Precision Forward Modeling of Controlled Source Electromagnetic Method Based on Weighted Average Extrapolation Method

Incremental Growth Analysis of a Cantilever Beam under Cyclic Thermal and Axial Loads.

Ratcheting analysis for cantilever beams subjected to the thermomechanical loads is presented using the finite element method. The cantilever beam is constrained along the vertical direction, and plane stress conditions are assumed according to the bilinear isotropic hardening model. Two points are considered to obtain areas of ratcheting by using linear extrapolation. The results and output diagrams for ratcheting with elastic-perfect plastic behavior are illustrated. It was revealed that the beam behaves elastically after the first considerable plastic strain, which is seen in two shakedown regimes. The numerical results are verified with known and analytical results in the literature. The results indicate a strong correlation between the outcomes from the cyclic ANSYS Parametric Design Language (APDL) model and Bree's analytical predictions. This consistency between the finite element analysis and the analytical solutions underscores the potential of finite element analysis as a powerful tool for addressing complex engineering challenges, offering a reliable and robust alternative to traditional analytical methods.

Fatigue Analysis of Shovel Body Based on Tractor Subsoiling Operation Measured Data

This paper aims to investigate the effects of soil penetration resistance, tillage depth, and operating speeds on the deformation and fatigue of the subsoiling shovel based on the real-time measurement of tractor-operating conditions data. Various types of sensors, such as force, displacement, and angle, were integrated. The software and hardware architectures of the monitoring system were designed to develop a field operation condition parameter monitoring system, which can measure the tractor’s traction force of the lower tie-bar, the real-time speed, the latitude and longitude, tillage depth, and the strain of the subsoiling shovel and other condition parameters in real-time. The time domain extrapolation method was used to process the measured data to obtain the load spectrum. The linear damage accumulation theory was used to calculate the load damage of the subsoiling shovel. The magnitude of the damage value was used to characterize the severity of the operation. The signal acquisition test and typical parameter test were conducted for the monitoring system, and the test results showed that the reliability and accuracy of the monitoring system met the requirements. The subsoiling operation test of the system was carried out, which mainly included two kinds of soil penetration resistances (1750 kPa and 2750 kPa), three kinds of tillage depth (250 mm, 300 mm, and 350 mm), and three kinds of operation speed (4 km/h low speed, 6 km/h medium speed, and 8 km/h high speed), totaling 18 kinds of test conditions. Eventually, the effects of changes in working condition parameters of the subsoiling operation on the overall damage of subsoiling shovels and the differences in damage occurring between the front and rear rows of subsoiling shovels under the same test conditions were analyzed. The test results show that under the same soil penetration resistance, the overall damage sustained by the subsoiling shovels increases regardless of the increase in the tillage depth or operating speed. In particular, the increase in the tillage depth increased the severity of subsoiling shovel damage by 19.73%, which was higher than the 17.48% increase due to soil penetration resistance and the 13.07% increase due to the operating speed. It should be noted that the front subsoiling shovels consistently sustained more damage than the rear, and the difference was able to reach 16.86%. This paper may provide useful information for subsoiling operations, i.e., the operational efficiency and the damage level of subsoiling shovels should be considered.