Method For Calculation Of Parameters Research Articles

Seismic responses and loss evaluation of RC frame with slotted infill walls

Infill walls are a primary source of structural loss under service level and design basis earthquakes, so developing high-performance infill wall is an effective strategy to reduce seismic loss. While several high-performance infill walls have been proposed, most studies only reveal the damage characteristics of infill walls at the component level. However, the interaction between infill walls and structures can alter the seismic response of structures and consequently affect the loss of infill walls under earthquakes. Therefore, it is necessary to investigate the seismic responses and loss of high-performance infill wall at the structural level. In this paper, the working mechanism and damage characteristics of the slotted infill wall (SIW) are firstly introduced and verified through cyclic loading test. Then, an in-plane hysteresis model of SIW is developed, and the calculation method of key parameters is proposed. Finally, a numerical analysis model of a 10-story frame with slotted infill wall (SIW-F) is developed to study the seismic response and seismic losses. The results indicate that SIW-F’s displacement response is larger than that of the frame with ordinary infill wall (OIW-F) on most floors. However, the floor acceleration response is less. The seismic loss of SIW-F is less than that of OIW-F, particularly under design basis earthquakes. The repair cost ratio of infill wall decreases from 19% to 8%, the total repair cost of the SIW-F decreases by 41%, and the total repair time also reduces by 25%.

Discussion on the thermodynamic calculation and adsorption spontaneity re Ofudje et al. (2023)

Accurate calculations and precise results are very important for the dissemination of scientific knowledge, whereas the errors of calculation will diminish the academic value of the paper. This discussion focuses on the calculation of thermodynamics and the determination of the spontaneity of adsorption processes in the paper of Ofudje et al. (2023). Ofudje et al. found that the apatite synthesized by chemical method (CHAp) has excellent adsorption properties for cadmium ions, which is an important contribution to the remediation of cadmium pollution. However, the calculation results of standard Gibbs free energy change (ΔGo), standard enthalpy change (ΔHo) and standard entropy change (ΔSo) of the adsorption of Cd2+ onto CHAp surface need to be corrected due to an incorrect calculation. Firstly, the partition coefficient (KD) with a dimension cannot be used for thermodynamic calculation. Secondly, the adsorbent mass (m) described by Ofudje et al. in different Sections is inconsistent, leading to incorrect results of Ko and ΔGo. When the appropriate value of the adsorbent mass is selected and the partition coefficient is converted to the standard adsorption equilibrium constant Ko, the calculated ΔGo is less than zero, which means that the adsorption is spontaneous. This discussion provides the correct calculation method of standard adsorption equilibrium constants and thermodynamic parameters, which can improve the reader's judgment and understanding of adsorption spontaneity.

Modeling and simulation of fire evacuation considering guiding factors: a case study of Shenyang subway interchange station

In case of fire, effective evacuation guidance can reduce evacuees’ hesitation time and improve evacuation efficiency. In this paper, an improved model of fire evacuation (guided fire cellular automata, GF-CA) is provided. First, the parameters of the improved model are quantified and analyzed to determine the parameter calculation method and variation law. Second, a typical subway interchange station in Shenyang is used as an example for evacuation simulation. Then, a lightweight building information modeling (BIM) is constructed and applied to the example combining the evacuation simulation software of Pathfinder and virtual reality technology for personnel evacuation simulation. Three types of simulation scenarios are examined, including simulation without guiding factors, simulation with guiding factors based on the improved model, and simulation based on the virtual reality experiment with guiding factors. The results show that the evacuation efficiency is increased by 75.63% after effective guidelines through personnel diversion and reasonable exit allocation, noting that the path results of the model are highly similar to those of the virtual reality experiment, which has good validity and rationality. Meanwhile, we analyze the guiding scheme and propose that we should pay attention to the position of the sign and the configuration of the conductor, and flexibly use the composite scheme, which provides effective technical support for improving evacuation safety and evacuation efficiency.

Cosimulation of Bistable Permanent Magnet Circuit Breakers

The breaking and closing coils of bi-stable permanent magnet circuit breaker (PMCB) shares magnetic circuit, which leads to the fast time-varying nonlinear coupling relationship between the permanent magnetic field and the electromagnetic field, and between the breaking and closing magnetic circuits, which brings difficulty to its simulation. Aiming at the difficulty, this paper designs a new co-simulation method: First, the equivalent magnetic circuit of the bi-stable permanent magnet actuator (PMA) is established, and the ternary correspondence relationship of its electromechanical parameters is proved analytically for the first time. Then, the “equivalent electric circuit” of magnetic circuit in dynamic process of bi-stable PMA is proposed for the first time by analogy with the transformer model, and the calculation method of the time-varying parameters in this model is given. Finally, the “equivalent electric circuit” of magnetic circuit is used as a link, so the hardware circuit, software strategy and PMCB are connected together to form a point-by-point closed-loop co-simulation method. This simulation method can reflect the dynamic interaction between the electromagnetic field and the permanent magnetic field of the breaking and closing magnetic circuits, and also can reflect the dynamic interaction between the control module and the PMCB. So this method lays the foundation for simulation design of the high-performance bi-stable PMCB.

Investigation of Fractal Fins towards Heat Transfer Properties in Thermal Storage System

To augment heat transfer in energy storage systems, fin inclusion is frequently adopted. This study critically examines various fin arrangements by employing a dimensionless parameter calculation method. Metrics of comparison include total melting time, dynamic temperature behavior, liquid fraction, and a unit performance indicator. The findings reveal that at Prandtl and Stefan numbers of unity, a Rayleigh number of 104 demarcates the boundary between convective and conductive heat transfer, thus determining the dominant heat transfer mode. By reorienting the internal fins within a four-fin structure, we observed improved transfer performance at low Rayleigh numbers (Ra ≤ 104); the liquid fraction approached unity with rising Rayleigh numbers. When assessing the unit performance metric, the reoriented four-fin structure manifested superior attributes in comparison to alternative configurations for Ra ≤ 5 × 104. However, at higher Rayleigh numbers, complex fin structures impede heat convection, and the two-fin structure makes the more effective configuration.

Effect of gradation and relative density on shear strength of coral sand

ABSTRACT Due to the wide particle size distribution of coral sand, There are significant differences in mechanical behaviour of coral sand with different particle size distribution. It is of great significance to propose a quantitative analysis method for mechanical properties considering the effect of gradation. In this study, 27 groups of coral sand specimens with particle size ranging from 5 mm to 0.125 mm were prepared. The consolidated undrained (CU) triaxial shear tests were carried out and the influence of gradation and relative density on the shear characteristic were discussed. The grading and relative density of coral sand are controlled by the median particle size (d50) and relative density (Dr), The results show that the peak deviator stress decreased, and the effective internal friction angle first increased and then decreased with the increase of d 50. Both the peak deviator stress and effective internal friction angle of coral sand increase with the relative density. A parabolic relationship was founded between the effect internal friction and d 50 as D r was constant. The effective friction angle peaked when d 50 was 2 mm. Finally, a calculation method of shear strength parameter considering the gradation and relative density of coral sand was proposed.

Research on accurate fire detection & early warning model for lithium-ion battery packs

To improve the fire detection & early warning accuracy for lithium-ion battery packs and reduce false alarms and missing reports, the fire occurrence mechanism and cause factors of lithium-ion battery packs were analyzed, the calculation method of these characteristic parameters and basic judgment conditions of thermal runaway occurrence were explored, and then a thermal runaway-induced fire spread model of lithium-ion battery packs was established. Next, the scheme and model for accurate detection and early warning of lithium-ion battery pack fire was designed. Furthermore, an accurate fire detection & early warning model of “characteristic parameter sorting and screening + comprehensive conditional judgment + grading implementation” was proposed. Experimental results demonstrate that the accurate fire detection & early warning model for lithium-ion battery packs built in this study would be feasible.

A discussion of fatigue properties of notched specimens subjected to prestressing treatment machined from FGH4097

Experimental and numerical investigations were performed to reveal the effect of prestress on the fatigue properties of FGH4097 so as to quantitatively evaluate the overspeed benefit of the disc of aeroengine. A corresponding experiment was performed to examine the effect of prestress on the fatigue life of FGH97. A complete model describing the fatigue properties of the prestressed notch specimen was proposed. After the modification of mean stress, stress gradient and prestressing treatment, the model is finally verified by fatigue test of presstressed notch specimens machined from FGH4097 with satisfactory accuracy and good engineering applicability. The new model highlights that for the variable fatigue loads, the introduction of appropriate prestress is expected to benefit to the notch specimens and certainly to the disc of aeroengine regards of their fatigue properties. Both the calculation method of fatigue life parameters and the prestress correction model are proved to have good prediction accuracy.

Research on potato (Solanum tuberosum L.) nitrogen nutrition diagnosis based on hyperspectral data

AbstractReducing the overapplication of nitrogen fertilizers to potatoes (Solanum tuberosum L.) can reduce production costs and their impact on the environment. One approach to produce these impacts is to reduce overapplications of fertilizers by using the nitrogen nutrition index (NNI = plant nitrogen concentration/critical nitrogen concentration) as a basis for in‐season nitrogen recommendations. The objective of this study was to create a remote sensing–based algorithm to estimate NNI. This study collected hyperspectral data (350–1830 nm) during the potato tuber formation period in 2022 and 2023. The climate regime for the study area was a mid‐temperate semiarid continental monsoon; in our study, three different spectral parameter calculation methods were employed. First, the empirical vegetation index, determined through a fixed two‐band calculation. Second, the optimal vegetation index, computed on a band‐by‐band basis. Lastly, the trilateral spectral approach, wherein the indicators are typically associated with the red edge, blue edge, and green edge. The optimum vegetation index had the highest correlation with NNI. The support vector machine, random forest (RF), and back propagation neural network models were used to create NNI prediction models. All machine learning models effectively estimated NNI, and during validation, the R2 (coefficient of determination) was >0.700. In general, the RF model outperformed the other models and during validation had an R2 of 0.869, a root mean square error of 0.052, and a relative error of 5.504%. This study demonstrates the scalability, simplicity, and cost‐effectiveness of combining hyperspectral technology and machine learning for rapid potato NNI estimation.

Development of an automated system for designing ball screws

The purpose of the study is labor saving, productivity gain of work and ball screws quality design pursuant to the use in numerical control machines. The article is devoted to the problem of automation of the designing of ball screws with return ports. These ball screws are an important element of the mechatronic modules of numerically controlled machines, as they affect the accuracy of linear displacement. Research methods: system-oriented analysis, structural analysis, methods of functional and object-matching programming, simulation. The novelty of the work: a method of three-dimensional parametric simulation of nuts of ball screws and a computation algorithm for a ball screw based on the synthesis of well-known techniques, has been developed. Research results: a software product consisting of modules that together automate the design process of nuts, screws, rigid supports, tilting saddles and ball screw coupling elements, has been developed. Conclusions: the developed methods for calculation of basic ball screw parameters can be used as the algorithmic basis of software products. Since the process for designing ball screw nuts with return ports has been automated, there are grounds for developing automation methods for other types of nuts.

Anatomical structure and morphometric parameters of the distal segment of the lacrimal drainage system

The article analyzes the literature data concerning the anatomical structure of the tear ducts with a focus on morphometric studies of individual structures. It is noted that, despite the high information content of cadaveric studies, most of the information to date has been obtained with the use of intravital radiation visualization methods. It is shown that the lacrimal drainage system has age, gender, and racial characteristics. Most studies focus on features of the bone nasolacrimal canal, while there is a relative shortage of research devoted to soft-tissue nasolacrimal duct. The analysis showed that most of the studies are devoted to particular morphometric indicators, which makes it difficult to obtain a complete objective picture of the size of the tear duct. Information about its volume can be found only in a couple of studies. The numerical values of the obtained data vary, which can be explained by a different approach to the selection of research subjects, sample sizes, anatomical criteria and the calculation method of morphometric parameters. There are only a few studies on morphometric parameters of the nasolacrimal duct in healthy humans, which is extremely important for determining the pathogenesis of disorders of the patency of the lacrimal drainage system.

A clustering-based differential privacy protection algorithm for weighted social networks.

Weighted social networks play a crucial role in various fields such as social media analysis, healthcare, and recommendation systems. However, with their widespread application and privacy issues have become increasingly prominent, including concerns related to sensitive information leakage, individual behavior analysis, and privacy attacks. Despite traditional differential privacy protection algorithms being able to protect privacy for edges with sensitive information, directly adding noise to edge weights may result in excessive noise, thereby reducing data utility. To address these challenges, we proposed a privacy protection algorithm for weighted social networks called DCDP. The algorithm combines the density clustering algorithm OPTICS to partition the weighted social network into multiple sub-clusters and adds noise to different sub-clusters at random sampling frequencies. To enhance the balance of privacy protection, we designed a novel privacy parameter calculation method. Through theoretical derivation and experimentation, the DCDP algorithm demonstrated its capability to achieve differential privacy protection for weighted social networks while effectively maintaining data accuracy. Compared to traditional privacy protection algorithms, the DCDP algorithm reduced the average relative error by approximately 20% and increases the proportion of unchanged shortest paths by about 10%. In summary, we aimed to address privacy issues in weighted social networks, providing an effective method to protect user-sensitive information while ensuring the accuracy and utility of data analysis.

Parameters calculation method of energetic model for symmetrical static hysteresis loop and asymmetrical minor loop

PurposeThis paper aims to propose an energetic model parameter calculation method for predicting the materials’ symmetrical static hysteresis loop and asymmetrical minor loop to improve the accuracy of electromagnetic analysis of equipment.Design/methodology/approachFor predicting the symmetrical static hysteresis loop, this paper deduces the functional relationship between magnetic flux density and energetic model parameters based on the materials’ magnetization mechanism. It realizes the efficient and accurate symmetrical static hysteresis loop prediction under different magnetizations. For predicting the asymmetrical minor loop, a new algorithm is proposed that updates the energetic model parameters of the asymmetrical minor loop to consider the return-point memory effect.FindingsThe comparison of simulation and experimental results verifies that the proposed parameters calculation method has high accuracy and strong universality.Originality/valueThe proposed parameter calculation method improves the existing parameter calculation method’s problem of relying on too much experimental data and inaccuracy. Consequently, the presented work facilitates the application of the finite element electromagnetic field analysis method coupling the hysteresis model.

Research on reasonable layout parameters of working faces based on the concept of harmonic extraction to reduce the damage of coal seam waiting for upward mining

Based on the idea of harmonic extraction, the problem of reducing the damage of the coal seam waiting for upward mining. Using the theoretical analysis method, a schematic diagram of coordinated mining along the dip direction of coal seam is established, and the calculation method of reasonable layout parameters of coal seam working face early mining is given. Based on the upward mining problem of the No.1 coal seam in the fifth panel of Zaoquan Coal Mine, the influence parameters of the No.2 coal seam, No.6 coal seam and No.7 coal seam mining on the No.1 coal seam were determined by similar simulation test. Then, the layout parameters of working face were determined. The research method of numerical calculation was used to evaluate the degree and uniformity of movement and deformation of the No.1 coal seam, combining five indicators: subsidence, horizontal movement, inclined deformation, curvature deformation, and horizontal deformation. The results indicate that when the working face is arranged using the layout parameters provided in this article, it can promote the further subsidence of the No.1 coal seam at the position of the remaining coal pillar. The movement and deformation indicators of the No.1 coal seam all reach the most uniform degree of the geological mining conditions, which can effectively offset the uneven deformation problem of the No.1 coal seam caused by the influence of the remaining coal pillars, making multiple mining operations a favorable condition for upward mining and achieving the goal of reducing the damage of the No.1 coal seam.

Establishment and applicability verification of hysteretic model of shear wall bottom corner dampers

In this study, the experimental results of a shear wall bottom corner damper (SWBCD) were investigated. It was found that the effects of the corrugated shear panel thickness, corrugated shear panel length, and flange plate thickness on the seismic performance from large to small. The failure process of the specimens was summarized; it was found that the high stiffness at the bend contributed to failure of cross-cracks in each long corrugated band of the corrugated shear panel in all specimens due to the geometric shape constraints of the corrugated shear panel. According to the calculation method for the skeleton curve parameters and the hysteretic rules of the SWBCD, a multilinear hysteretic model of the SWBCD was established. Using a corrugated steel plate-reinforced concrete composite shear wall with bottom corner dampers (RSPCW) as the application background, based on the layer shell model, a reasonable equivalent simulation method for an embedded corrugated steel plate based on the tension strip model was proposed. The hysteretic model of the SWBCD was modified according to the deformation requirements of the bottom corner damper. The twoNodeLink element representing the SWBCD was placed in the height range under the boundary element at both ends of the RSPCW. The ability of the hysteretic model to accurately reflect the nonlinear analysis of the SWBCD was verified.

Design, manufacture, and experiments of lightweight CFRP hydraulic cylinder tube without metal liner

AbstractHydraulic cylinders are widely used in aircraft rudder surface control, landing gear retraction, flaps and speed brakes retraction, ground steering driving, and engine thrust reverser control. The huge weight of hydraulic cylinders severely limits the aircraft's potential for increased range, maneuverability, energy efficiency, and carrying capacity. To achieve the maximum weight reduction, the carbon fiber reinforced polymer (CFRP) hydraulic tube without a metal liner is designed in this paper. In response to the lack of a parameter calculation method for CFRP hydraulic tubes, the accurate calculation method is developed through mechanical modeling and analysis of parameter influence law. For the structure design challenges of connection, sealing, and friction of CFRP hydraulic tube without metal liner, we have proposed and verified the wave contour inlaid structure, three leak‐proof solutions of the connection interface, the leak‐proof structure of the wound CFRP body and the seal friction pair. For the difficulties of multi‐material and high‐precision molding, a new process of split manufacturing‐combined molding is developed to achieve high‐precision and low‐cost manufacturing. Finally, the prototype is manufactured and tested by the presented method, and its weight reduction ratio is 56.64% compared with the original metal hydraulic tube. This study has further matured the application of CFRP hydraulic tubes without metal liners and has great lightweight benefits in aircraft.Highlights CFRP hydraulic tube without metal liner is designed to reduce weight. An accurate calculation method of CFRP parameters is developed. Connection structure, leak‐proof structure, and seal friction pair are designed. The high‐precision and low‐cost molding process is innovatively proposed.

Crack Segmentation Extraction and Parameter Calculation of Asphalt Pavement Based on Image Processing.

Crack disease is one of the most serious and common diseases in road detection. Traditional manual methods for measuring crack detection can no longer meet the needs of road crack detection. In previous work, the authors proposed a crack detection method for asphalt pavements based on an improved YOLOv5s model, which is a better model for detecting various types of cracks in asphalt pavements. However, most of the current research on automatic pavement crack detection is still focused on crack identification and location stages, which contributes little to practical engineering applications. Based on the shortcomings of the above work, and in order to improve its contribution to practical engineering applications, this paper proposes a method for segmenting and analyzing asphalt pavement cracks and identifying parameters based on image processing. The first step is to extract the crack profile through image grayscale, histogram equalization, segmented linear transformation, median filtering, Sauvola binarization, and the connected domain threshold method. Then, the magnification between the pixel area and the actual area of the calibration object is calculated. The second step is to extract the skeleton from the crack profile images of asphalt pavement using the Zhang-Suen thinning algorithm, followed by removing the burrs of the crack skeleton image using the connected domain threshold method. The final step is to calculate physical parameters, such as the actual area, width, segments, and length of the crack with images obtained from the crack profile and skeleton. The results show that (1) the method of local thresholding and connected domain thresholding can completely filter noise regions under the premise of retaining detailed crack region information. (2) The Zhang-Suen iterative refinement algorithm is faster in extracting the crack skeleton of asphalt pavement, retaining the foreground features of the image better, while the connected-domain thresholding method is able to eliminate the missed isolated noise. (3) In comparison to the manual calibration method, the crack parameter calculation method proposed in this paper can better complete the calculation of crack length, width, and area within an allowable margin of error. On the basis of this research, a windowing system for asphalt pavement crack detection, WSPCD1.0, was developed. It integrates the research results from this paper, facilitating automated detection and parameter output for asphalt pavement cracks.

Prediction of comprehensive dynamic performance for probability screen based on AR model-box dimension

In order to evaluate the comprehensive dynamic performance of probability screen and select the appropriate working conditions, a dynamic model of probability screen vibration system is established. Then, the calculation method of the dynamic characteristic parameters, based on the time series Auto Regression (AR) model of vibration test, is used. The relationship among the comprehensive dynamic characteristics, the screening efficiency and the box dimension of probability screen vibration system is analyzed, and Least Square Support Vector Machine (LSSVM), Generalized Regression Neural Network (GRNN) and Back Propagation Neural Network (BPNN) are used to predict the screening efficiency with box dimension. The analysis result shows that the screening efficiency, the stability, the response rapidity and the comprehensive dynamic characteristic of the system are all related to the box dimension of time series. As for the complexity of probability screen vibration system, it affects the comprehensive dynamic performance, and ultimately touches the screening efficiency of the probability screen; The best working conditions for the system are selected by the curve between box dimension and the working condition parameter; Taking box dimension as the only input variable, the prediction accuracy of the screening efficiency is high by using LSSVM,GRNN and BPNN methods, the prediction results are stable and reliable, and the box dimension can be used as a single input variable to predict the screening efficiency, it has the advantages of fewer input parameters, high prediction efficiency, and high prediction accuracy, which has great potential for expanding application space and further research value.

Type series of resonant vibration equipment for concrete mixtures compaction and its main parameters calculation method

Introduction. Increasing the energy efficiency of vibration technology poses a number of challenges for its developers. A promising direction for reducing energy costs for driving vibration machines is the use of the resonance phenomenon. Due to the dynamic properties of the oscillatory system, it is possible to significantly reduce the power consumption of resonant vibration equipment, and in some cases, improve the quality of the products. The purpose of this article is to develop a standard range of resonant vibration equipment for compacting concrete mixtures and a methodology for calculating its main parameters.The object of research is the oscillatory system of a vibrating machine, consisting of two masses connected by the elastic and dissipative elements. In addition, the first mass is connected to a fixed base through elastic and dissipative elements.Materials and methods. The basic principles of theoretical mechanics, mathematical modelling and statistical processing of results were used in the research.Results. According to the research results, it was established that with an increase in the mass ratio of the oscillatory system, the dynamic coefficient decreases, and the width of the resonant zone increases. The regression equations are given. It has been established that with increasing rigidity of the working body, the dynamic coefficient decreases, and the horizontal section on the frequency response, the width of which does not change significantly, shifts to the region of higher frequencies. With an increase in the damping coefficient, the dynamic coefficient decreases, and the width of the resonant zone and the frequency range practically do not change. A wide range of nomenclature and masses of precast reinforced concrete justifies the development of a standard-size range of resonant vibration equipment. A standard range of light (up to 2 tons), medium (2-6 tons) and heavy (6-10 tons) types has been developed. Based on the analysis and generalization of research results, a method for calculating resonant vibration equipment for compacting concrete mixtures has been developed, which makes possible to increase its energy efficiency.

Analysis of mechanical characteristics and normal operating conditions of magnetic seals

Aiming at the leakage failure problem caused by the accidental disengagement of the sealing interface due to the failure of the magnetic seal force balance system, taking a certain type of aero-engine magnetic seal as an example, the mechanical analysis model of the magnetic seal is established, and the mechanical conditions for normal sealing work are deduced according to the set of equilibrium equations of force. The analysis process of the normal operation is proposed, and the calculation method of the key mechanical parameters of the magnetic seal is determined. On this basis, the influence of operating conditions on the normal operating mechanical conditions is analyzed. The results show that the primary sealing face contact pressure, the maximum contact pressure of the secondary sealing face, and the traction torque of the rotor determine the normal operating condition of the magnetic seal. Excessive chamber pressure and rotational speed will increase the contact pressure of the primary sealing face, leading to increased wear of the face and slippage between the O-Ring 1 and the shaft; too little differential pressure and rotational speed will lead to the disengagement of the graphite ring/stator, which ultimately leads to the failure of the seal. Severe vibration reduces the contact pressure of the primary sealing face and increases the risk of the primary sealing face disengagement.