Method For Parameters Research Articles

Self-calibration method for geometric parameters based on feature point projection trajectories in Cone-beam Computed Laminography

Cone-beam computed laminography (CBCL) is an X-ray three-dimensional imaging method that is suitable for large plate-like objects. Geometric parameter calibration is crucial during CL imaging to prevent geometric artifacts in the reconstructed image. This study introduced a self-calibration method employing feature-point projection trajectories for CL geometric parameters. The method constructed point projection trajectory models for the system’s geometric parameters and optimized the best fit of these models to the characteristic point projection trajectories to solve for the geometric parameters of the system. Furthermore, this study examined the impact of the feature point location in the object coordinate system on the parameter calibration accuracy and reduced the required feature point locations from 11°to 4°using the alternating optimization algorithm. The imaging results demonstrated the ability of the method to achieve high-accuracy calibration of CL system geometric parameters, reducing the calibration error of the rotational axis tilt angle α from 1.1% to 0.08% while exhibiting resilience to noise. The proposed method enabled the calibration of all CL system geometric parameters without the model calibration, laying the groundwork for rectifying image geometric artifacts and enhancing CL imaging quality. Moreover, this method presents a novel approach for CT system geometric parameter calibration.

Simulation study on thermal performance of solar coupled air source heat pump system with phase change heat storage in cold regions

The development of efficient and clean heating technologies is profoundly significant for the reduction of carbon emissions in cold regions. This paper puts forth a novel solar-coupled air source heat pump system integrated with phase change heat storage technology, which is well-suited for regions with such climatic conditions. A numerical model of the components and coupled systems is established using the lumped parameter method, and an iterative method is employed for the computational solution in MATLAB software. A variety of system performance aspects are then simulated and analysed following the configuration of component structural parameters and initial operating conditions. The results of the simulations indicate that an increase in the phase change temperature interval of the phase change materials leads to a higher average heat release power. In particular, a 2 °C increase in the phase change temperature interval results in an increase in the heat release power of over 10 %. Furthermore, when the system is applied in typical cold regions, including Kunming, Hangzhou, Lhasa, and Harbin, the average coefficient of performance is 10.23, 8.87, 8.49, and 7.70, respectively. The proportion of solar energy input contributes to an increase in system efficiency across all regions. A case study of Hangzhou reveals that the incorporation of solar energy into the system results in an increase in efficiency of 70.91 %. This research provides valuable operational methods and site selection recommendations for engineering practices, laying a theoretical foundation for its widespread application in cold regions.

A multi-objective co-optimization method of controller parameters for the overall system of small pressurized water reactor

Small pressurized water reactors (SPWRs) normally have complicated and varying working conditions, and become an important direction for nuclear energy development. The overall system of SPWR, including the reactor coolant average temperature control system, the feedwater control system of the once-through steam generator (OTSG), the steam turbine speed control system and the steam dump control system, is used to guarantee the safe and stable operation. The overall system of SPWR is designed with multiple PI controllers. To accomplish intelligent self-tuning of PI controller parameters, reduce the dependence on human engineering experience, and improve the control performance of the overall system, a multi-objective co-optimization method(MMOCO) with PI controller parameters for overall system of SPWR is proposed. Firstly, based on the coordinated control theory and PI control algorithm, the overall system of SPWR is established. Then, a MMOCO for the overall system of SPWR is designed with the Non-Dominated Sorting Genetic Algorithm-II (NSGA-II). Finally, to compare the performance of the controller parameters derived from the MMOCO and the controller parameters obtained via the engineering tuning method, step load decrease transients are selected. The results show that the ability to control the overall system of SPWR is effectively improved after applying the MMOCO.

A Fast Multi-Objective Optimization Method for Control Parameters of High-Speed Maglev Vehicle-Bridge System

A fast multi-objective optimization method (FMOOM) is proposed by optimizing control parameters to improve the dynamic performance of a high-speed maglev vehicle–bridge system. This approach involves generating the corresponding dynamic response to the sampled control parameters using a theoretical model of a high-speed maglev vehicle–bridge system, followed by establishing an adaptive surrogate model for the relationship between the control parameters and the dynamic response extrema. In the second step, we combine the adaptive surrogate model and the multi-objective gradient-based optimizer (MOGBO) algorithm to obtain the Pareto solution set satisfying different performance indexes. Additionally, the control parameters are optimized using the fuzzy comprehensive evaluation method. In the numerical simulation, we investigate five maglev trains and ten-span simply supported beam bridges and the theoretical model is verified by comparing the calculations with the measured results. The optimization effect of FMOOM is analyzed under different working conditions. The results show that the adaptive surrogate model has good prediction accuracy based on the radial basis function. Furthermore, the Pareto solution distribution of different schemes using FMOOM is reasonable, and the optimization results are as expected. Compared with the reference scheme, the dynamic response of the maglev vehicle–bridge system is smaller after being subjected to FMOOM optimization, and the six performance indexes are dramatically improved.

Comparative Analysis of Structure and Motion of Vision Logistics Robotic Arms

This paper combines visual recognition and robotic arm, optimizes the design of robotic arm structure, and researches the logistics robotic arm with six degrees of freedom and visual perception ability to enrich the logistics robotic use scene. Firstly, the visual recognition system is installed on the existing six-degree-of-freedom robotic arm, and the coordinate system is established by the light bar recognition method combined with the D-H parameter method. Secondly, a kinematic simulation model was established by using MATLAB, and the state of the joints was analyzed by using forward and inverse kinematic simulation and fifth degree polynomial interpolation. Finally, the actual logistics fixed-point transportation task is designed for trajectory planning. The results show that the robotic arm is able to be able to perform different grasping tasks in non-structural environments, around the visual analysis of the robotic arm as well as the optimization of the motion track, to enhance the efficiency of the comprehensive use of visual and tactile information, to improve the adaptability of the robotic hand grasping, and to be able to meet the precise control of the pick-up process and the use of the realization of the payload grasping and dexterous movement. The research in this paper provides a certain reference value for the propulsion robot arm to perform intelligent grasping tasks.

Multi-objective Optimization and Decision-Making Method for Laser Polishing Process Parameters of D2 Die Steel Based on NSGA-II and TOPSIS-EWM

Multi-objective Optimization and Decision-Making Method for Laser Polishing Process Parameters of D2 Die Steel Based on NSGA-II and TOPSIS-EWM

Local heat transfer measurements of the fin on the blade crown by infrared thermography

Current research on heat transfer of the labyrinth surface mainly focuses on the whole structure made of the same material, but the heat conduction from the tip to the root will affect the measurement of the heat transfer coefficient. To minimize the influence of heat conduction, copper strips are embedded on the surface of the fin made of bakelite. The inverse heat transfer problem is solved using the temperatures collected by an infrared thermal imager to determine the local convective heat transfer coefficient. The error of the lumped parameter method is smaller compared to the differential solution. Constant heat flux experiments are used to validate the experimental results, and numerical analysis is performed to analyze the heat transfer mechanism. The flow field, the Nu number distribution, and fitting correlations of the fins are obtained. By comparing and analyzing the heat transfer coefficients obtained by the three methods, it is found that the lumped parameter method can eliminate the influence of heat conduction on the surface. Taking the lumped parameter method as a reference, the errors of stable heat flow and numerical calculation were 21 % and 4.7 %, respectively. Due to the influence of the vortex direction, the Nu number distribution along the height of the windward surface of the second fin is different from the others. The Nu number distribution along the x-direction on the top surface of the fin is similar to the tip of the windward surface. Along the flow direction, the average Nu number on the top surface of the first fin is 1.2 times that of the second one.

Uncertainty Optimization of Vibration Characteristics of Automotive Micro-Motors Based on Pareto Elliptic Algorithm

The NVH (Noise, Vibration, and Harshness) characteristics of micro-motors used in vehicles directly affect the comfort of drivers and passengers. However, various factors influence the motor’s structural parameters, leading to uncertainties in its NVH performance. To improve the motor’s NVH characteristics, we propose a method for optimizing the structural parameters of automotive micro-motors under uncertain conditions. This method uses the motor’s maximum magnetic flux as a constraint and aims to reduce vibration at the commutation frequency. Firstly, we introduce the Pareto ellipsoid parameter method, which converts the uncertainty problem into a deterministic one, enabling the use of traditional optimization methods. To increase efficiency and reduce computational cost, we employed a data-driven method that uses the one-dimensional Inception module as the foundational model, replacing both numerical models and physical experiments. Simultaneously, the module’s underlying architecture was improved, increasing the surrogate model’s accuracy. Additionally, we propose an improved NSGA-III (Non-dominated Sorting Genetic Algorithm III) method that utilizes adaptive reference point updating, dividing the optimization process into exploration and refinement phases based on population matching error. Comparative experiments with traditional models demonstrate that this method enhances the overall quality of the solution set, effectively addresses parameter uncertainties in practical engineering scenarios, and significantly improves the vibration characteristics of the motor.

Expression of p16INK4a, FLOT2, and EGFR in oropharyngeal carcinoma, prognostic significance and correlation with clinicopathological characteristics.

Various factors can affect the survival of patients with oropharyngeal cancer. We assessed the expression of protein p16INK4a, Flotillin2, epidermal growth factor receptor, and other clinicopathological features and their prognostic value for this type of cancer. We gathered patient data on demographics, clinicopathological characteristics, treatment patterns, and outcomes. Histologically and by immunochemistry staining we determined expression of prognostic factors and molecular biomarkers. The primary endpoints were overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS). Survival was assessed using the Kaplan-Meier method and Cox regression model analyses of potential prognostic parameters. After a median follow-up of 78 months, the median OS was 41 months, with an event recorded in 77.8% of patients. Median DFS was 22 months, 37 patients (51.4%) had disease relapse. The DSS survival rate was 58.3% with a median survival of 68 months. In regards to molecular biomarkers previously mentioned, there was no statistical significance for survival categories. After conducting a multivariate analysis of significant variables, we found that only recurrence, vascular invasion, and surgical intervention remained as factors with independent effects on both OS and DFS. Recurrence and the N stage were identified as independent prognostic factors for DSS. Our analysis underscores the complexity of factors that collectively influence survival following the diagnosis of OPSCC. Several factors were found to be statistically significant. These factors included the type of surgical procedure, disease relapse, vascular invasion, lymphatic invasion, perineural invasion, advanced T stage of the disease, N stage of the disease, and smoking status. The significance of these factors may vary across different types of survival. This analysis did not find any significant impact on survival from the growth factors tested, namely epidermal growth factor receptor, Flotillin2, and p16INK4a, in the applied regression models.

Research on the Identification Method of Respiratory Characteristic Parameters during Mechanical Ventilation

Research on the Identification Method of Respiratory Characteristic Parameters during Mechanical Ventilation

A novel molecular structure parameter determination method for biomass thermochemical conversion mechanism investigation

The low-grade energy properties and high O content of biomass limit its efficient energy utilization. Torrefaction is known to be one of the most promising thermochemical conversion methods for upgrading biomass. 250 °C Gas-pressurized (GP) torrefaction realizes deep decomposition of hemicellulose in biomass to as high as 99.7% by deoxygenation and aromatization. However, the above thermochemical conversion mechanism at molecular-level is currently scant. Here, a novel molecular structural parameter method and pure hemicellulose torrefaction were employed to investigate the thermochemical conversion mechanism. Results demonstrate that O content of 250 °C GP torrefied hemicellulose was as low as 28.8 wt%, which was considerably lower than 44.6 wt% of traditional torrefied hemicellulose. There are five deoxygenation mechanisms of hemicellulose during the GP torrefaction: deacetylation, decarbonylation, dehydroxylation, ring opening and cyclization reactions to produce CO2/CH3COOH, CO, H2O, ketones/aldehydes and furans. The deoxygenation and aromatization reactions cause the chemical structure of hemicellulose evolution significantly, these mechanisms are: active hemicellulose undergo aromatization reaction through cyclization and deoxidation to generate preliminary 2-ring furans polymer, followed by stepwise polymerization reactions to form 4-ring and 6-ring furans polymers. These polymerization reactions further greatly enhance deoxygenation reaction. A thermochemical conversion mechanism model is developed based on the above investigation. This work provides a novel method for determining the molecular structure and reaction mechanism of thermochemical converted biomass.

Enhanced Thermal Management in Oil Spray-Cooled Motors: A Novel Approach to Replacing NTC Sensors

<div>Motor temperature plays a critical role in controlling pump speed and regulating coolant flow to prevent overheating during motor operation. Presently, negative temperature coefficient (NTC) sensors are commonly used for motor temperature measurement, typically installed at the motor winding’s end for ease of installation. However, in oil spray-cooled motors, the temperature distribution is uneven due to the spray pipe, leading to lower temperatures near the pipe compared to other areas. This results in a challenge where relying solely on NTC measurements at the winding end may not meet the motor’s cooling requirements. To address this issue and improve temperature signal accuracy, a novel approach has been developed that utilizes four signals derived from the motor controller: motor speed, motor torque, along with oil pump speed, oil temperature. Employing the lumped parameter method, a model established in Simulink aims to estimate the average temperature in the motor’s high-temperature region. Subsequently, this value is corrected and directly utilized as an input signal for motor thermal management. The proposed approach not only enhances motor temperature monitoring accuracy but also mitigates operational risks, thereby prolonging motor lifespan and enhancing its overall safety.</div>

Addendum to: Research on electromagnetic torque and fault parameter identification of pumped storage machine under power generation state based on optimized network parameter method

Addendum to: Research on electromagnetic torque and fault parameter identification of pumped storage machine under power generation state based on optimized network parameter method

Probabilistic evaluation method for the stability of large underground cavern considering the uncertainty of rock mass mechanical parameters: A case study of Baihetan underground powerhouse project

For deep large underground cavern projects under complex geological conditions, the determination of rock mass mechanical parameters and stability analysis is fraught with a great deal of uncertainty. This paper proposes a set of methods for estimating rock mass mechanical parameters and probabilistic stability assessment suitable for construction characteristics of large underground caverns. On the one hand, according to the Hoek-Brown criterion and Monte Carlo simulation, a dynamic estimation method for rock mass mechanical parameters is proposed by using Rock Mass Rating (RMR), the uniaxial compressive strength (UCS) of intact rock, and the material constant (mb) as input parameters. On the other hand, considering the uncertainty of rock mass mechanical parameters, a probabilistic evaluation method applicable to the unloading response characteristics of rock mass (including displacement and fracturing zones) around the large cavern is put forward, combining the point estimation method and numerical simulation. The proposed methods were applied to an underground powerhouse, with an excavation span of 34 m and height of 88.7 m, at the Baihetan hydropower station in the southwest of China. Based on extensive field investigations and tests, the probability distributions of key rock mass mechanical parameters were obtained. Furthermore, the high sensitivity of input parameters in the H-B criterion for estimating rock mass mechanical parameters were revealed. Through dynamic simulation, the probability distributions of the displacement and fracturing zones in surrounding rock during the layer-by-layer excavation of the cavern were presented. Comprehensive on-site tests showed that the simulated results were in basic agreement with the actual unloading response behavior during the cavern excavation, validating the correctness and applicability of the proposed methods. The study provides a relatively comprehensive approach for estimating rock mass mechanical parameters and stability evaluation in similar underground engineering projects, and also has guiding significance for predicting and preventing engineering rock mass hazards.

Kinematics analysis and simulation of bionic five-finger manipulator

Abstract To address the complexity of traditional manipulator structures, a bionic five-finger manipulator has been designed and developed. After introducing the manipulator’s structure and functionality, the kinematic model was established using the D-H parameter method, followed by the analysis of forward and inverse kinematics. The fingertip pose was derived using the homogeneous transformation formula, and the accuracy of the theoretical analysis was validated by comparing the mathematical and MATLAB simulation results. The Monte Carlo method was employed to determine the accessible motion space of the mechanical fingertip. Subsequently, trajectory planning for the manipulator was performed based on known initial and end finger angles. A comparison with ADAMS simulation results demonstrated the rationality of the mechanical finger’s movement space, stable speed, and compliance with actual grasping requirements. This study lays a theoretical foundation for the subsequent parameter optimization of the manipulator.

Time-optimal trajectory planning for manipulator based on an improved sparrow search algorithm

Abstract With the development of industrial automation, it is crucial to use manipulators for efficient painting. To solve the problem of inefficient trajectory planning of manipulators in the point-to-point painting process, this paper proposes a time-optimal trajectory planning method based on an improved sparrow search algorithm. Initially, the standard D-H parameter method is used to establish the kinematic model of the manipulator. To ensure the continuity of each joint in the manipulator, a 3-5-3 polynomial interpolation function is utilized to construct the motion trajectory in joint space. Subsequently, the improved sparrow search algorithm is utilized to optimize the point-to-point motion trajectory of the manipulator with a constraint on motion time. Finally, simulations carried out in MATLAB demonstrated that the manipulator, which was optimized by using the improved sparrow search algorithm, exhibited a significant increase in motion efficiency compared to its pre-optimization state. Additionally, the movements of the manipulator’s joints were smooth.

Study of Simulation Method of Porosity and Permeability Parameters of Salt Deposition Reservoir Based on Phase Equilibrium Calculation

Study of Simulation Method of Porosity and Permeability Parameters of Salt Deposition Reservoir Based on Phase Equilibrium Calculation

Test Method for Key Parameters of Small-Caliber Gun Internal Ballistics Based on Double-Layer Double-Grid Structure Strain

Test Method for Key Parameters of Small-Caliber Gun Internal Ballistics Based on Double-Layer Double-Grid Structure Strain

An Optimization Method of Attitude Control Parameters Based on Genetic Algorithm for the Boost-Glide Rocket

An Optimization Method of Attitude Control Parameters Based on Genetic Algorithm for the Boost-Glide Rocket

Эргонимикон как важнейший компонент языкового ландшафта современного полиэтнического города (на примере Уфы)

The aim of the study is to provide a comprehensive overview of the main structural, semantic and linguocultural features of the ergonymicon of a modern multiethnic city in relation to the specifics of its characteristic linguistic situation. The article defines the conceptual foundations for the study of the linguistic landscape of the city; examines the originality of the ergonymicon as an integral component of the onomastic urban space; carries out a multidimensional description of ergonyms recorded in the territory of the city of Ufa. The scientific novelty of the study lies in the fact that, using the example of Ufa, a systematic analysis of the ergonymicon of a modern multiethnic city is carried out according to various parameters (method of education, origin, linguistic and cultural features) and the conditionality of the specifics of these units by intra- and extra-linguistic factors is determined. As a result of the study, it was found that the main features of the Ufa ergonymicon are multilingualism, active appeal to national identity and regional affiliation in the nomination of urban objects, and widespread use of borrowings. It was also found that when creating ergonyms, Russian language units are used most often. Elements of the national (Bashkir) language are less frequently used compared to English-language ones. Urban specificity is especially noticeable in ergonyms created based on toponyms, anthroponyms, and ethno-cultural realities.