Calculation Error Research Articles

Denominator and Composite Calculation Errors.

Denominator and Composite Calculation Errors.

Denominator and Composite Calculation Errors in Study of Health System Low-Value Services.

Denominator and Composite Calculation Errors in Study of Health System Low-Value Services.

Analysis of Short-range Contact Forces in Peridynamics Endowed with an Improved Nonlocal Contact Model

The motion and deformation laws of multi object interactions in computational models depend on contact algorithms. However, research on the peridynamic contact problem is limited. In this paper, in order to effectively prevent non-physical intrusion during contact, the inherent problems of the contact algorithm in peridynamic discrete models are analyzed, and a force boundary contact method using nonlinear contact stiffness is proposed. Through numerical calculations and geometric analysis of the peridynamic discrete model, the characteristics and reasons for the variation of contact force in the peridynamic contact model under fixed contact stiffness are discovered. To address the nonlinear reduction of contact force and potential non-physical intrusion in the peridynamic contact model, a force boundary peridynamic contact method is proposed by introducing a nonlinear changing contact stiffness function. Then the characteristics of contact force variation in different kinds of contact functions are studied and the parameter setting of contact functions is discussed. The results show that this method can effectively prevent non-physical intrusion and the calculation error is acceptable. This paper lays a foundation for further research on contact constitutive model based on Peridynamic framework.

ECGEFNet: A two-branch deep learning model for calculating left ventricular ejection fraction using electrocardiogram.

Left ventricular systolic dysfunction (LVSD) and its severity are correlated with the prognosis of cardiovascular diseases. Early detection and monitoring of LVSD are of utmost importance. Left ventricular ejection fraction (LVEF) is an essential indicator for evaluating left ventricular function in clinical practice, the current echocardiography-based evaluation method is not avaliable in primary care and difficult to achieve real-time monitoring capabilities for cardiac dysfunction. We propose a two-branch deep learning model (ECGEFNet) for calculating LVEF using electrocardiogram (ECG), which holds the potential to serve as a primary medical screening tool and facilitate long-term dynamic monitoring of cardiac functional impairments. It integrates original numerical signal and waveform plots derived from the signals in an innovative manner, enabling joint calculation of LVEF by incorporating diverse information encompassing temporal, spatial and phase aspects. To address the inadequate information interaction between the two branches and the lack of efficiency in feature fusion, we propose the fusion attention mechanism (FAT) and the two-branch feature fusion module (BFF) to guide the learning, alignment and fusion of features from both branches. We assemble a large internal dataset and perform experimental validation on it. The accuracy of cardiac dysfunction screening is 92.3%, the mean absolute error (MAE) in LVEF calculation is 4.57%. The proposed model performs well and outperforms existing basic models, and is of great significance for real-time monitoring of the degree of cardiac dysfunction.

Numerical solutions of stochastic delay integro-differential equations by block pulse functions

This paper presents an efficient numerical method for solving nonlinear stochastic delay integro-differential equations based on block pulse functions. Firstly, the equation is transformed into an algebraic system by the integral delay operator matrixes of block pulse functions. Then, error analysis is conducted on the method. Finally, some numerical examples are provided to validate the method. This work provides numerical solutions for the stochastic delay integro-differential equations by global approximation method. This method has the advantages of simple calculation and higher error accuracy.

Performance analysis of a micro pneumatic turbine using actual driving conditions simulation

Currently, nearly all literature discussing the performance of a micro pneumatic turbine using computational fluid dynamics (CFD) adopts either single reference frame simulation (SRFS) or multiple reference frame simulation (MRFS), with previously specified inlet pressure, outlet pressure and rotation speed. The overly constrained boundary conditions prevent the simulations from obtaining the turbine performance accurately under actual driving conditions, leading to calculation errors. This article proposes actual driving conditions simulation (ADCS) to predict the performance of a micro pneumatic turbine. In this approach, the inlet and outlet pressures are specified, while the turbine inertia moment is set according to the physical model of the turbine. SST k-ω turbulence model and dynamic grid technology are used to compute intricately time-varying flow parameters for obtaining the performance of the turbine. The results of SRFS, MRFS, ADCS and theory calculation (TC) demonstrate that the torque of a micro pneumatic turbine increases with an increase in supply pressure. The average torque calculated by ADCS is closer to that of TC compared with SRFS and MRFS. Moreover, the relative error of rotation speed between ADCS and experiments ranges from 2% to 10.9%, which is lower than that of between TC and experiments at the same working conditions.

Study on the influence of working condition variation on lubrication characteristics of EHA internal pump

The operational characteristics of Electro-Hydraulic Actuator(EHA) result in the EHA internal pump facing complex conditions of variable speed, pressure and even direction, resulting in poor lubrication state of friction pairs. To study the evolution of lubrication states under varying working conditions, a joint simulation model using Simerics-MP+(Version: 5.2.13, https://www.simerics.com) and MATLAB(Version: R2020a, https://www.mathworks.com/products/matlab.html) was established, focusing on the gear ring/shell friction pair as the subject of study. The model was used to predict the micro-motion trajectory of the gear ring, and the results were validated through experimental measurements of dynamic changes. Results indicate that the simulation model can accurately predict oil film variations, with a calculation error of less than 7.6% for oil film thickness. The reduction in speed and the increase in load pressure will deteriorate the lubrication characteristics of the oil film in the friction pair. Under pump operating conditions, when the direction reversing rate increases from 20,000 rpm/s to 40,000 rpm/s, the average oil film thickness increases by 23.64%, while the fluctuation rate decrease by 2.57%. Similarly, when the direction reversing pressure decreases from 10 MPa to 5 MPa, the average oil film thickness increases by 22.39%, and the fluctuation rate decreases by 8.17%. During pump-motor working condition switching, an increase in the switching rate from 10,000 rpm/s to 40,000 rpm/s results in a 10.33% increase in average oil film thickness and a 20.9% decrease in fluctuation rate. This study significantly contributes to enhancing our comprehension of the evolutionary patterns of friction pairs in EHA internal pumps under varying operational conditions.

QRIS Adoption as a Cashless Transaction: A Case Study of Meatball Seller in Makassar City

The previously free QRIS adoption now incurs fee of 0.3% for small businesses and 0.7% for medium and large businesses, as determined by Bank Indonesia. This phenomenon has sparked debates and divided opinions among meatball traders in Makassar City. As a metropolitan city in Eastern Indonesia, Makassar is the city with the largest population of MSMEs compared to other cities in Eastern Indonesia. Despite the Trade Department’s efforts to promote QRIS, many meatball traders in Makassar city have not adopted it. This research aims to analyze the perceptions of meatball traders regarding their interest in implementing cashless through adopting QRIS as a potential for expanding sales and reducing manual errors in cash calculations. This qualitative research involved informants (16 buyers and 20 meatball sellers), in research data analysis techniques using the help of NVivo software. The research results found that QRIS adoption provides various conveniences, security and expands customer reach as well as increases efficiency in the cashless business transaction process. Keywords: QRIS Adoption; Cashless; Meatball Seller; Makassar City

Human-Centred Branding in the Emerging Context of Narratives Warfare: Based on Worth-Living Marketing Management

The recent global events involving the Ukraine-Russia war and the Gaza-Israel have highlighted the increasing complexity of brand interactions with the brand community in the context of narrative warfare. Furthermore, various industries are embracing the concept of Industrial Revolution 5.0, emphasising human-centeredness that is value-driven. Based on this, this research aims to explore the dimensions of human-centred branding based on worth-living marketing management in the context of narrative warfare. Design/methodology: This research methodology is a systematic literature review encompassing an in-depth examination of 52 scientific articles and books, complemented by 23 articles from specialised marketing sites and 16 news articles specifically focused on the two most recent wars. Findings: Findings show that the context of the war of narratives encompasses 10 key dimensions and human-centred branding based on worth-living marketing management in narrative warfare contexts, which includes 14 main concepts. Practical implications: The findings of this research give valuable insight to brands (personal, corporate, government, political) to reduce the amount of their calculation errors in the unstable conditions of narrative warfare and to manage existing risks with more precise strategic management. Social implications: This research strengthens the brand's responsibility towards human issues, such as social, environmental, ethical, and political issues, and accordingly adds to the meaning of collective life, ethics, and collective trust. Originality/value: This research is a pioneer in the in-depth study of the intersection of narrative warfare and human-centred branding, and exploring the dimensions of these two concepts and combining them adds to the value of the existing literature.

A simple algorithm to derive virtual non-contrast electron density from dual-energy computed tomography data for radiotherapy treatment planning.

The use of iodinated contrast-enhancing agents in computed tomography (CT) improves the visualization of relevant structures for radiotherapy treatment planning (RTP). However, it can lead to dose calculation errors by incorrectly converting a CT number to electron density. This study aimed to propose an algorithm for deriving virtual non-contrast (VNC) electron density from dual-energy CT (DECT) data. This algorithm was developed by extending the formula previously developed by Saito, which enables the calculation of the electron density of human tissue through weighted subtraction of CT numbers acquired from DECT scans. To investigate the feasibility of the proposed VNC algorithm, we performed analytical DECT image simulations at 90 and 150kV/Sn on virtual phantoms consisting of various tissue/iodine surrogates with known mass densities and elemental compositions. Two different shapes of phantoms made of water-mimicking surrogates were generated as inputs: a circular phantom (33cm diameter) for calibration and an elliptical phantom (33cm width and 28cm height) for validation. The circular phantom was equipped with inserts of human-tissue-mimicking substitutes, pure water, and iodine-enhanced soft-tissue substitutes (2, 5, 10, and 15mg/mL iodine). The elliptical phantom contained inserts of reference human tissues, iodine-enhanced soft-tissue substitutes (2, 2.5, 5, 7.5, 10, 15, and 20mg/mL iodine), and a 10-mm-diameter core of 4mg/mL iodine surrounded by a blood-mimicking base material. The performance of the proposed algorithm was evaluated by comparing the accuracy of VNC electron densities with those of non-contrast (NC) base materials (water- or blood-mimicking surrogates). The derived algorithm enabled the calculation of VNC electron density in a manner similar to that of unenhanced human tissues by adapting a VNC-specific weighting factor, thereby eliminating the intermediate step of converting CT numbers to electron density. The simulated results showed that the VNC algorithm could almost completely remove the contrast in the electron density image between iodine-enhanced and base materials. The relative deviations of simulated VNC electron density values from the corresponding pre-contrast value were within±0.4% for all tested materials, with a root-mean-square error (RMSE) of 0.2%. Within the limits of the analytical DECT image simulation used in this study, the simple VNC algorithm could effectively provide accurate VNC electron densities for iodine-enhanced materials. This may allow the contrast agent to be used for CT scans during RTP without compromising dose calculation accuracy.

Dynamic modeling and guidance analysis of a ferromagnetic continuum robot with geometric discretization and base linear motion

Abstract With the advancement of robotics in medicine in recent years, diverse and promising applications for ferromagnetic continuum robots (FCRs) have been introduced. These robots utilize an electromagnetic actuation system for movement and control, which leads to reduced tissue damage, significantly shorter surgery durations, and improved patient recovery times. Recent research in FCR modeling highlights the critical challenge of developing a dynamic model to assess system behavior in real-time, crucial for maximizing benefits in medical applications. In this paper, the geometric discretization method and Lagrange’s principle are used to derive the dynamic equations of a FCR under the influence of an external magnetic field. This approach enables the examination of the system’s behavior at any given moment, providing a suitable foundation for designing various controllers based on the model. Given the electromagnetic system used in steering the FCRs, an analysis of the magnetic field in both ideal and real conditions is conducted to enhance reliability for medical applications. Simulation results indicate that the robots deform in a direction different from the magnetic field direction, demonstrating non-planar deformation characteristics. Furthermore, comparison with experimental data demonstrates that the theoretical framework accurately predicts the robot’s deformation, with calculation errors less than 5%.

Azo dye adsorption on ZrO2 and natural organic material doped ZrO2

Natural wastes and inorganic adsorbents are used for the removal of diazo dye Congo red (CR), which causes water pollution and is a carcinogen, from wastewater. Organic waste olive pulp (ZK), inorganic ZrO2 (Zr) and three different weight percent ZK/Zr (organic/inorganic) binary adsorbent systems prepared by ball-milling method were investigated for the effective removal of CR from wastewater. Characterization of both single and binary adsorbent systems were carried out by ATR/FTIR and SEM. According to the Langmuir isotherm, qmax values for ZK, Zr, 25ZK-75Zr, 50ZK-50Zr and 75ZK-25Zr at 45 °C were 588 mgg-1, 13 mgg-1, 46 mgg-1, 65 mgg-1 and 84 mgg-1, respectively. According to Frumkin-Fowler–Guggenheim and Temkin isotherms, the adsorption heat was found to be exothermic for ZK and 75ZK-25Zr at all three temperatures, while it was found to be endothermic for Zr, 25ZK-75Zr and 50ZK-50Zr. It was observed that the ΔG° values calculated from the thermodynamic data were consistent with the values in the Flory-Huggings isotherm. According to the kinetic data, it was observed that all adsorbents except ZK obeyed the pseudo-first-order rate equation. It was shown by error calculations that the experimental data obeyed the Langmuir or Freundlich isotherms better. It was observed that a new and effective organic/inorganic adsorbent system could be obtained by adding ZK to ZrO2 for the removal of Congo red (CR) from water.

Research on Automatic Tracking and Size Estimation Algorithm of “Low, Slow and Small” Targets Based on Gm-APD Single-Photon LIDAR

In order to solve the problem of detecting, tracking and estimating the size of “low, slow and small” targets (such as UAVs) in the air, this paper designs a single-photon LiDAR imaging system based on Geiger-mode Avalanche Photodiode (Gm-APD). It improves the Mean-Shift algorithm and proposes an automatic tracking method that combines the weighted centroid method to realize target extraction, and the principal component analysis (PCA) method of the adaptive rotating rectangle is realized to fit the flight attitude of the target. This method uses the target intensity and distance information provided by Gm-APD LiDAR. It addresses the problem of automatic calibration and size estimation under multiple flight attitudes. The experimental results show that the improved algorithm can automatically track the targets in different flight attitudes in real time and accurately calculate their sizes. The improved algorithm is stable in the 1250-frame tracking experiment of DJI Elf 4 UAV with a flying speed of 5 m/s and a flying distance of 100 m. Among them, the fitting error of the target is always less than 2 pixels, while the size calculation error of the target is less than 2.5 cm. This shows the remarkable advantages of Gm-APD LiDAR in detecting “low, slow and small” targets. It is of practical significance to comprehensively improve the ability of UAV detection and C-UAS systems. However, the application of this technology in complex backgrounds, especially in occlusion or multi-target tracking, still faces certain challenges. In order to realize long-distance detection, further optimizing the field of view of the Gm-APD single-photon LiDAR is still a future research direction.

Study on the Axial Compressive Behavior and Constitutive Relationship of Lightweight Mixed Ceramic Concrete.

To thoroughly study the stress-strain relationship of lightweight mixed ceramic concrete, this paper conducts axial compressive strength tests on three groups of lightweight mixed ceramic concrete specimens with different types and contents as the basis. It establishes the elastic modulus calculation formula and compressive stress-strain formula for lightweight mixed ceramic concrete by combining with the current standards and related research. The results show that lightweight mixed ceramic concrete, made of a mixture of different types and densities of ceramic grains, has better mechanical properties and deformation properties. The calculation errors of the modulus of elasticity formulas, derived from the experimental results for the three groups of lightweight mixed ceramic concretes, are all controlled within 5%. The average relative errors of the fitting results of stress-strain curves for the three groups of specimens and the measured data are as low as 6.66%, 3.16%, and 3.39%. The errors between the experimental values of the modulus of elasticity of different studies and the predicted values based on the formula in this paper were controlled within 17%, and the average relative errors between the predicted and experimental results of the stress-strain curves for the three groups of specimens were 2.64%, 8.94%, and 17.50%. This paper innovatively constructs a prediction model of key mechanical parameters of lightweight mixed ceramic concrete, which can provide a reference and experimental basis for the structural analysis and application of lightweight mixed ceramic concrete.

Rancang Bangun Sistem Informasi Penggajian Guru Berbasis Website di Smas Plus Guna Cipta Cimanggung

Design of Teacher Payroll Information System is a system created to solve problems in the financial department, especially the payroll of teachers and staff at SMAS Plus Guna Cipta Cimanggung. The existence of a system that runs by recording payroll transactions and calculations still using semi-computerization, making it vulnerable to calculation errors and data redundancies. Data that is still separate causes the payroll process to take longer. As well as the difficulty of making payroll reports and pay slips because they have not been automatically computerized. The purpose of this research is to facilitate teachers or officers concerned in managing teacher payroll. And all users can access this information system more flexibly anywhere and anytime. The research method used is the Object Oriented Analysis and Design (OOAD) system with its development model, namely the Rational Unified Process (RUP) and its system design using the Unified Modeling Language (UML The results of the study show that this system can facilitate the process of managing teacher salaries more precisely and efficiently with easy access anywhere and anytime. Moreover, this system has a feature to manage attendance data using QR Codes.

Selecting analytical method of leakage inductance calculation for optimizing high-voltage test transformer design

AN ACTUAL PROBLEM in transformer design is to optimize its design, since it allows you to create a competitive transformer. One of the objective functions in optimization algorithms for high-voltage test transformers is the ratio of the leakage inductive reactance of the transformer, reduced to the secondary side, to the load capacitance. Since the objective functions in the optimization procedure must be found many times, it is advisable to use approximate analytical calculation methods to calculate the leakage inductance. THE PURPOSE of the article is to analyze the error of the traditional analytical method for calculating the leakage inductance of power transformers with a rectangular axial cross-sections of the windings, and to develop a refined analytical method that takes into account the main design feature of high-voltage test transformers, which consists in the trapezoidal shape of the secondary winding cross-section. The refined method takes into account the change in the number of turns in the radial direction while maintaining the basic assumptions of the traditional method. METHODS. The error is studied by comparing the calculation results using these methods with the results of a numerical calculation of leakage inductance based on a 3D magnetostatic field, which are accepted as accurate. RESULTS. It is shown that the calculation error using the method proposed in the article is significantly reduced compared to the error of the method developed for power transformers with rectangular winding cross-sections. The ranges of changes in the relative geometric parameters of the base transformer have been determined, in which the error of this calculation method does not exceed 10%. The TGI 50/100 transformer, whose rated power is 5 kVA, was chosen as the base transformer. The developed analytical method is recommended for high-voltage test transformers optimization algorithms.

Automated vision-based bolt loosening detection and localization for operating hydraulic turbine rotors

Turbine rotors are susceptible to bolt loosening and detachment due to factors such as vibration, stress concentration, and material degradation during the prolonged operation of hydropower units. These issues can result in significant safety incidents and economic losses. This article presents a novel vision-based automatic detection method for identifying loose bolts in turbine rotors by analyzing the angle between marking lines on the top surfaces of studs and nuts. The proposed method integrates enhanced you only look once version 8 (YOLOv8) for object detection, DeepSORT for multitarget tracking, DeepLabV3+ for image segmentation, and Theil-Sen estimation for line fitting. This approach effectively locates loose bolts on the rotor and determines the loosening angle. Experiments were conducted during the commissioning of a large hydroelectric unit, yielding results that demonstrate an average loosening angle calculation error 0.633°. With a loosening threshold established at 2°, the method achieves a detection accuracy of 98.88%. The proposed method does not depend on the historical states of the bolts and provides precise identification of bolt loosening angle up to 180°, thereby making it suitable for application to operating turbine rotors.

Linking Error Estimation in Haberman Linking

Haberman linking is a widely used method for comparing groups using the two-parameter logistic item response model. However, the traditional Haberman linking approach relies on joint item parameter estimation, which prevents the application of standard M-estimation theory for linking error calculation in the presence of differential item functioning. To address this limitation, a novel pairwise Haberman linking method is introduced. Pairwise Haberman linking aligns with Haberman linking when no items are missing but eliminates the need for joint item parameters, allowing for the use of M-estimation theory in linking error computation. Theoretical derivations and simulation studies show that pairwise Haberman linking delivers reliable statistical inferences for items and persons, particularly in terms of coverage rates. Furthermore, using a bias-corrected linking error is recommended to reduce the influence of sample size on error estimates.

Increasing the location accuracy of the operating unit of a three-axis metal-cutting machine tool: application of the differential geometric model of volumetric errors

The article is devoted to increasing the volumetric accuracy of multi-axis machine tools. Based on the model of measurement and calculation of the volumetric geometric error of machine tools presented by the authors, a method has been developed which allows to signifi cantly improve the accuracy of the movement of the operating unit of a three-axis metal-cutting machine tool to a given point. The astatic law and the calculation of the coordinate correction according to the differential geometric model of the volumetric error are used to control the movement of the operating unit. The developed method is implemented programmatically and allows to perform the correction in the control program represented in G-code. As a result of experiments on software correction of volumetric errors according to the developed method, conducted at the State Engineering Centre of the Moscow State University of Technology “STANKIN” on a threeaxis CNC machine tool, a signifi cant reduction (up to 90 %) of geometric volumetric errors was shown. The developed method can be used to improve the accuracy of metal-cutting machine tools by creating postprocessors that calculate corrections to the coordinates set in the control system based on the results of interferometric measurements.Keywords: volumetric accuracy, interference measurements, three-axis machine tools, machine tool accuracy, geometric errors, astatic control law, mathematical modelling, differential geometry

ЕЛЕКТРОСТАТИЧНЕ ПОЛЕ В ПОВІТРЯНОМУ ПРОМІЖКУ СИСТЕМИ ПЛОСКО-ПАРАЛЕЛЬНИХ ЕЛЕКТРОДІВ ДЛЯ ОБРОБКИ КРАПЕЛЬ ВОДИ БАР’ЄРНИМ РОЗРЯДОМ

This study investigates the electrostatic field in a discharge chamber (DC) designed for water purification from organic pollutants using pulsed barrier discharge (PBD) technology. The DC consists of vertical plane-parallel electrodes, with an air gap containing water droplets between them, and one of the electrodes is insulated from the air gap by a dielectric (barrier). The research employs computer modeling in both two-dimensional and three-dimensional setups. Therefore, the aim of this work is to compare the distribution of the electrostatic field intensity of PBD in the air gap and the electrical capacitance of the DC to establish the optimal distance between droplets and to determine the calculation error using the two-dimensional DC model. Electrostatic field modeling was performed using the Poisson equation and the finite element method. Calculations were performed for two-dimensional and three-dimensional models with conditions of a droplet diameter of 1 mm, a gas gap length of 3.36 mm, and an applied voltage of 3 kV. The influence of droplet conductivity and the distance between them on the characteristics of the electrostatic field in the gas medium and in the droplets was investigated. A comparison of the calculated capacitance values of the DC in the two-dimensional and three-dimensional models depending on the distance between the droplets was conducted. The research results can be used in the application of electro-discharge technology based on pulsed barrier discharges in water treatment systems, specifically in selecting the parameters for the movement of the treated liquid in the plasma zone. References 10, figures 7.