Differences In Calculated Results Research Articles

Sequential bias-corrected weighted least squares solution of mixed additive and multiplicative error models

In the era of big data, the number of observations in adjustment calculations may reach tens or even hundreds of thousands. When dealing with these large dataset problems, many matrix operations are often required. At this time, the dimensions of the matrix will be large, which will generate a great computational burden. At present, no research results have been published on the computational efficiency of bias-corrected weighted least squares (bcWLS) for mixed additive and multiplicative error models (MAMEM). Sequential adjustment (SEA) groups the observations for calculation and can provide the same computational precision while greatly improving computational efficiency. This paper applies the idea of SEA to the calculation of bcWLS and proposes an iterative solution for sequential bcWLS (SEbcWLS). Using three simulation experiments to verify the effectiveness of our method, it was found that when the number of observations is 10000, the effect is better when the number of groups does not exceed 100, achieving the same precision as the original method while having high computational efficiency. The calculation results of line fitting and plane fitting are not affected by the number of grouping groups. For DEM (Digital elevation model) experiments with strong nonlinearity, when the number of grouping groups is too large, the effect is not very good, but the calculation efficiency is also higher than the original method, and the difference in calculation results is not significant.

Prediksi Financial Distress Menggunakan Model Artificial Neural Network pada Perusahaan Perhotelan yang Terdaftar di BEI Tahun 2017-2021

This study aims to determine early warning models, differences in calculation results, and prediction results of financial distress using the Artificial Neural Network (ANN) model on data testing of hotel industry companies listed on the Indonesia Stock Exchange (IDX) from 2017-2021. In this study, researchers used quantitative research methods where the results obtained from this study were in the form of numbers or data whose values were numbered. The population in this study are companies Hotels, Resorts & Cruise Lines which are listed on the Indonesia Stock Exchange in 2017-2021 with a total of 17 companies. The data processing procedure in this study begins with calculating financial ratios using Microsoft Excel, then analyzing descriptive statistics, and testing the artificial neural network model using the PYTHON programming language to predict financial distress conditions in companies.

Modeling Of Generator Neutral Ground System Using Labview 2017 Application IEEE std C62.92.2TM

The generator is a device for an important source of electrical energy, so the continuity of the generator operation must be maintained and well controlled, in controlling the grounding on the generator can use in control with software such as MATLAB and Modeling the design of the grid grounding system using LabView 2017, Determination of the grounding system for the neutral value of the generator through the distribution transformer, can be done through manual calculation. The use of many parameters considered in the calculation to obtain appropriate and measurable results there is a possibility of repeated calculations. This is very difficult and causes a large difference in calculation results. Therefore, a computer-based computing system is needed to overcome problems like this. Several papers have developed calculations of the amount of generator neutral grounding required that consider the voltage level, short circuit fault current and ground fault protection system. This paper discusses modeling and simulation in designing generator neutral grounding using LabView 2017 application. The goal is to be easier, faster and more accurate. As an implementation of modeling, data from std C62.92.2TM-2017 is used.

A Comparative Study on Effective One-Group Cross-Sections of ORIGEN and FISPACT to Calculate Nuclide Inventory for Decommissioning Nuclear Power Plant

Background: The radionuclide inventory calculation codes such as ORIGEN and FISPACT collapse neutron reaction libraries with energy spectra and generate an effective one-group crosssection. Since the nuclear cross-section data, energy group (g) structure, and other input details used by the two codes are different, there may be differences in each code’s activation inventory calculation results. In this study, the calculation results of neutron-induced activation inventory using ORIGEN and FISPACT were compared and analyzed regarding radioactive waste classification and worker exposure during nuclear decommissioning.Materials and Methods: Two neutron spectra were used to obtain the comparison results: Watt fission spectrum and thermalized energy spectrum. The effective one-group cross-sections were generated for each type of energy group structure provided in ORIGEN and FISPACT. Then, the effective one-group cross-sections were analyzed by focusing on <sup>59</sup>Ni, <sup>63</sup>Ni, <sup>94</sup>Nb, <sup>60</sup>Co, <sup>152</sup>Eu, and <sup>154</sup>Eu, which are the main radionuclides of stainless steel, carbon steel, zircalloy, and concrete for decommissioning nuclear power plant (NPP).Results and Discussion: As a result of the analysis, <sup>154</sup>Eu and <sup>59</sup>Ni may be overestimated or underestimated depending on the code selection by up to 30%, because the cross-section library used for each code is different. When ORIGEN-44g, -49g, and -238g structures are selected, the differences of the calculation results of effective one-group cross-section according to group structure selection were less than 1% for the six nuclides applied in this study, and when FISPACT-69g, -172g, and -315g were applied, the difference was less than 1%, too.Conclusion: ORIGEN and FISPACT codes can be applied to activation calculations with their own built-in energy group structures for decommissioning NPP. Since the differences in calculation results may occur depending on the selection of codes and energy group structures, it is appropriate to properly select the energy group structure according to the accuracy required in the calculation and the characteristics of the problem.

MEASURED AND CALCULATED INTEGRAL REACTIVITY OF CONTROL RODS IN RSG-GAS FIRST CORE

The control rod worth is one of the important parameters for the operation of a nuclear reactor. Proper measurement and calculation of the control rod worth are essential for the safe reactor operation under normal and transient conditions that are initiated by a postulated event such as a stuck rod, control rods ejection, etc. This paper presents calculation results of integral reactivity of the RSG-GAS research reactor first core and its comparison with the experimental data. Calculations were performed using the continuous energy transport code Serpent 2 with ENDF/B-VIII.0 nuclear data. Integral reactivity measurement was done by compensating method with control rod bank, regulating rod, and reactivity meter. Calculations are carried out for each method used in control rod measurement data with an aim to validate calculated results to experimental data. Compared with the measured experiment data, there are no significant differences in calculation results of integral reactivity. The maximum difference of the control rod's total reactivity is 1.26% compared to the measurement carried out by compensating method with regulating rod.

Coal Consumption Determination Method and Its Application Based on Actual Running State for Unit

In the daily energy-saving statistics of coal-fired power stations, the imbalance of the total standard coal consumption often occurs. The fundamental reason is that the boundary conditions of the steam turbine side heat rate calculation and the boiler efficiency calculation are not unified. The article first analyzes the existing calculation methods, and points out that the anti-equilibrium calculation of boiler thermal efficiency lies in various loss calculations, and the key to the calculation of steam turbine heat consumption rate lies in the calculation of heat absorption. The heat consumption rate of the steam turbine is based on the flow into the turbine. The loss of working fluid on the turbine side, such as oxygen exhaust, high-pressure operation exhaust, sampling, valve leakage, etc., have been taken into account. Sampling, heat tracing in the ammonia station, and leakage from the boiler side run-off do not affect the boiler efficiency, nor the calculation of the turbine heat consumption rate, but affect the overall operation level of the unit. This article researchs the calculation method of coal consumption for power supply,taking a 600MW condensing power plant as an example, the main reasons for the difference in calculation results are analyzed, which lays the foundation for energy-saving diagnosis and energy-saving potential of the whole plant.

Effect of aggregates spatial distribution on three-dimensional transport of chloride ions in reinforced concrete

The spatial distribution of coarse aggregates directly affects the three-dimensional transport of chloride ions and the accumulation of chloride ions on the surface of steel bar in reinforced concrete. The meso-structure of a concrete specimen was recognized through X-ray CT technology. In considering the diffusion of chloride ions both in mortar matrix and ITZs, a three-dimensional transmission model was established to numerically simulate the diffusion of chloride ions in concrete, which was furtherly verified by electronic microprobe technology. To avoid the correlation of data, 100 sets of independent three-dimensional numerical samples were generated with real coarse aggregates extracted from concrete specimen. The influence of spatial distribution of coarse aggregates on diffusion of chloride ions was statistically analyzed, and the differences between three-dimensional transmission and two-dimensional transmission of same sections were studied. The research shows that the special distribution of coarse aggregates can cause the non-uniform distribution of chloride ions both in spatial and time scale. The concentration distribution of chloride ions satisfies the Normal distribution through Kolmogorov-Smirnov test and Chi-square test. For two-dimensional and three-dimensional transmission, the greater the depth, the greater the differences in calculation results.

Building constructions modelling problems in modern cae-systems

This article is about choosing building structure analysis model question. Construction analysis model type choice affects result of counting. Result accuracy and reliability depends on analysis scheme choice. Using modern computers, there is a lot of alternative abilities of creation construction analysis model. This article is made to understand these analysis models features and their influence on result. An example of counting beam in six independent CAD systems is shown. Engineering simulation and design software, which base on finite elements method, were chosen for analysis. These counting models differ from each other only by geometrical scheme. Beam geometry modeling is performed using beam elements, shell elements and solid elements. The comparison of beam calculation results with its beam, shell and solid elements analysis scheme modelling was performed. The analysis of single factor (geometric scheme) influence on the results of beam calculation is shown. It was defined, that the choice of calculation complex does not affect the calculation result, if the geometrical counting models are completely identical. It was defined, that in case creating construction with various types finite elements there are differences in the calculation results. Difference in calculation results, using different geometrical models, is seen in using the same complex and in comparison of different complexes. It was defined, that difference in calculating internal forces and moments in beam for different geometrical models can be more than 10%.

Optimization of GATE and PHITS Monte Carlo code parameters for uniform scanning proton beam based on simulation with FLUKA general-purpose code

Although three general-purpose Monte Carlo (MC) simulation tools: Geant4, FLUKA and PHITS have been used extensively, differences in calculation results have been reported. The major causes are the implementation of the physical model, preset value of the ionization potential or definition of the maximum step size. In order to achieve artifact free MC simulation, an optimized parameters list for each simulation system is required. Several authors have already proposed the optimized lists, but those studies were performed with a simple system such as only a water phantom. Since particle beams have a transport, interaction and electromagnetic processes during beam delivery, establishment of an optimized parameters-list for whole beam delivery system is therefore of major importance. The purpose of this study was to determine the optimized parameters list for GATE and PHITS using proton treatment nozzle computational model. The simulation was performed with the broad scanning proton beam. The influences of the customizing parameters on the percentage depth dose (PDD) profile and the proton range were investigated by comparison with the result of FLUKA, and then the optimal parameters were determined. The PDD profile and the proton range obtained from our optimized parameters list showed different characteristics from the results obtained with simple system. This led to the conclusion that the physical model, particle transport mechanics and different geometry-based descriptions need accurate customization in planning computational experiments for artifact-free MC simulation.

Critical and Subcritical Mass Calculations of Curium-243 to -247 Based on JENDL-3.2 for Revision of ANSI/ANS-8.15

Critical and subcritical masses were calculated for a sphere of five curium isotopes from 243Cm to 247Cm in metal and in metal-water mixtures considering three reflector conditions: bare, with a water reflector or a stainless steel reflector. The calculation were made mainly with a combination of a continuous energy Monte Carlo neutron transport calculation code, MCNP, and the Japanese Evaluated Nuclear Data Library, JENDL-3.2. Other evaluated nuclear data files, ENDF/B-VI and JEF-2.2, were also applied to find differences in calculation results of the neutron multiplication factor originated from different nuclear data files. A large dependence on the evaluated nuclear data files was found in the calculation results: more than 10%Δk/k relative differences in the neutron multiplication factor for a homogeneous mixture of 243Cm metal and water when JENDL-3.2 was replaced with ENDF/B-VI and JEF-2.2, respectively; and a 44% reduction in the critical mass by changing from JENDL-3.2 to ENDF/B-VI for 246Cm metal. The present study supplied basic information to the ANSI/ANS-8.15 Working Group for revision of the standard for nuclear criticality control of special actinide elements. The new or revised values of the subcritical mass limits for curium isotopes accepted by the ANSI/ANS-8.15 Working Group were finally summarized.

Critical and Subcritical Mass Calculations of Curium-243 to-247 Based on JENDL-3.2 for Revision of ANSI/ANS-8.15.

Critical and subcritical masses were calculated for a sphere of five curium isotopes from 243Cm to 247Cm in metal and in metal-water mixtures considering three reflector conditions: bare, with a water reflector or a stainless steel reflector. The calculation were made mainly with a combination of a continuous energy Monte Carlo neutron transport calculation code, MCNP, and the Japanese Evaluated Nuclear Data Library, JENDL-3.2. Other evaluated nuclear data files, ENDF/B-VI and JEF-2.2, were also applied to find differences in calculation results of the neutron multiplication factor originated from different nuclear data files. A large dependence on the evaluated nuclear data files was found in the calculation results: more than 10%Δk/k relative differences in the neutron multiplication factor for a homogeneous mixture of 243Cm metal and water when JENDL-3.2 was replaced with ENDF/B-VI and JEF-2.2, respectively; and a 44% reduction in the critical mass by changing from JENDL-3.2 to ENDF/B-VI for 246Cm metal. The present study supplied basic information to the ANSI/ANS-8.15 Working Group for revision of the standard for nuclear criticality control of special actinide elements. The new or revised values of the subcritical mass limits for curium isotopes accepted by the ANSI/ANS-8.15 Working Group were finally summarized.