Classical Calculation Methods Research Articles

Comparison of Measured and Calculated Porosity Parameters of Woven Fabrics to Results Obtained with Image Analysis.

Porosity, the measure of the open spaces within a fabric structure, is a decisive factor in the performance of textiles. It influences breathability, permeability to liquids or gases, and suitability for various industries such as apparel, medical, and technical textiles. This study compares classical porosity calculation methods with non-destructive image analysis for 24 woven fabric samples that differ in density and weave pattern. Factors such as fabric density, weave pattern, illumination conditions, magnification, and the influence of the Otsu and Yen threshold algorithms were considered. The multifactor ANOVA statistical analysis shows that fabric density and weave pattern significantly influence porosity, with illumination playing an important role, while the threshold algorithm has a minor influence. A strong correlation is found between the actual fabric porosity and the results of the image analysis, except for double-sided illumination (reflective and transmissive), where the correlation is weakest. This comprehensive investigation provides valuable insights into the reliability of different porosity assessment approaches, which is essential for applications in various textile industries.

Research on Rejoining Bone Stick Fragment Images: A Method Based on Multi-Scale Feature Fusion Siamese Network Guided by Edge Contour

The rejoining of bone sticks holds significant importance in studying the historical and cultural aspects of the Han Dynasty. Currently, the rejoining work of bone inscriptions heavily relies on manual efforts by experts, demanding a considerable amount of time and energy. This paper introduces a multi-scale feature fusion Siamese network guided by edge contour (MFS-GC) model. Constructing a Siamese network framework, it first uses a residual network to extract features of bone sticks, which is followed by computing the L2 distance for similarity measurement. During the extraction of feature vectors using the residual network, the BN layer tends to lose contour detail information, resulting in less conspicuous feature extraction, especially along fractured edges. To address this issue, the Spatially Adaptive DEnormalization (SPADE) model is employed to guide the normalization of contour images of bone sticks. This ensures that the network can learn multi-scale boundary contour features at each layer. Finally, the extracted multi-scale fused features undergo similarity measurement for local matching of bone stick fragment images. Additionally, a Conjugable Bone Stick Dataset (CBSD) is constructed. In the experimental validation phase, the MFS-GC algorithm is compared with classical similarity calculation methods in terms of precision, recall, and miss detection rate. The experiments demonstrate that the MFS-GC algorithm achieves an average accuracy of 95.5% in the Top-15 on the CBSD. The findings of this research can contribute to solving the rejoining issues of bone sticks.

ПРАКТИКА ПРИМЕНЕНИЯ ЦИФРОВЫХ ТЕХНОЛОГИЙ ЭКОНОМИЧЕСКОЙ ОЦЕНКИ ЗЕМЕЛЬ ЛЕСНОГО ФОНДА

The article describes the main methods used in the practice of assessing forest lands, discusses the prospects for the introduction of modern information technologies in the field of forest management. The importance of creating a unified information base is determined, which will greatly facilitate the monitoring of the forest land assessment process. Special attention is paid to the existing models of digital information processing and obtaining the necessary result much faster and of better quality than using classical calculation methods. The discounted value of rental income is used as a criterion for assessing forest lands in the article. This approach is considered the main one based on the long cycle of creating marketable products in forestry, since it allows taking into account all changes in the amount of income over time. The forest fund of the Russian Federation is a combination of forests, forest and non-forest lands with a total area of more than 1100 million hectares, which makes up more than 70% of the entire land and is one of the main types of national economy. The territories of the forest fund are unevenly distributed, depending on climatic and anthropogenic factors. All the listed characteristics of the forest fund of the Russian Federation necessitate the introduction of the latest digital technologies for their timely accounting and qualitative assessment, which will allow them to be used most efficiently.

Research on an Assembly Building Buffer Zone Based on Gray Critical Chain

The complexity of construction in prefabricated buildings makes it vulnerable to uncertainty in project timelines, and traditional project timeline management is insufficient to control project timelines for prefabricated buildings. Therefore, research on project timeline management for prefabricated buildings is needed in order to optimize project timelines and improve project execution rates. This study proposed an improved method of setting prefabricated building buffer zones through the use of improved grey critical chain technology. Five major factors affecting project timelines in actual prefabricated construction projects were selected: personnel experience, degree of prefabrication, technical complexity, reasonableness of construction plans, and degree of construction space availability. The OPA technique was introduced and combined with the entropy weight method to improve the comprehensive weight coefficient of the grey critical chain calculation of the factors affecting the timeline. Other influencing coefficients were determined, and a new calculation method for the size of prefabricated building buffer zones was proposed. Monte Carlo simulations were conducted in Matlab on actual construction projects to ensure the scientific rationality of the improved method. The results showed that compared with the classical buffer calculation methods (cut-and-paste method, C&PM and square root standard deviation method, RSEM), the project timeline was reduced by 14.3% and 11.7%, respectively, using the improved method. The improved method not only reduces project uncertainties, but also achieves the goal of optimizing project timelines, and it is reasonable and effective. The results of the study provide a direction for the project timeline management of prefabricated building critical chains, and this method can be applied to the planning and management of prefabricated building buffer zones.

A topic-aware classifier based on a hybrid quantum-classical model

In the era of Large Language Models, there is still potential for improvement in current Natural Language Processing (NLP) methods in terms of verifiability and consistency. NLP classical approaches are computationally expensive due to their high-power consumption, computing power, and storage requirements. Another computationally efficient approach to NLP is categorical quantum mechanics, which combines grammatical structure and individual word meaning to deduce the sentence meaning. As both quantum theory and natural language use vector space to describe states which are more efficient on quantum hardware, QNLP models can achieve up to quadratic speedup over classical direct calculation methods. In recent years, there is significant progress in utilizing quantum features such as superposition and entanglement to represent linguistic meaning on quantum hardware. Earlier research work has already demonstrated QNLP’s potential quantum advantage in terms of speeding up search, enhancing classification tasks’ accuracy and providing an exponentially large quantum state space in which complex linguistic structures can be efficiently embedded. In this work, a QNLP model is used to determine if two sentences are related to the same topic or not. By comparing our QNLP model to a classical tensor network-based one, our model improved training accuracy by up to 45% and validation accuracy by 35%, respectively. The QNLP model convergence is also studied when varying: first, the problem size, second, parametrized quantum circuits used for model’s training, and last, the backend quantum simulator noise model. The experimental results show that strongly entangled ansatz designs result in fastest model convergence.

The Integral Momentum Balance Applied to Metering Orifices to Obtain the Pressure Drop and the Flow Rate With High Accuracy

Abstract The established method of calculating the pressure loss and the flow rate of flows through metering orifices requires empirical correction coefficients. In this paper, a completely momentum-based approach is presented to predict the flow rate and the pressure loss. It is shown that the proposed approach is as precise as the established method but without any empirical coefficient. The required physical coefficients solely base on physics. They pinpoint the sources of the inaccuracy that effects the employment of an empirical correction coefficient to correct the established method—and confirm the empirical correction coefficient on a physical foundation. Ultimately, the physical coefficients evade the effort to experimentally calibrate the theory with the experiments. The integral momentum balance is applied to a control volume comprising the orifice reaching up to the respective pressure metering cross section. Depending on the location of the control volume's open boundaries, the pressure loss or the flow rate can be obtained. To substitute the integral with averaged expressions, the introduced physical coefficients are deduced directly from numerical simulations and parametrized by simple analytical fit functions to complete the momentum-based approach. The numerical model and the proposed approach are both verified by the comparison with the results obtained by the standard ISO 5167:2003. The agreement with the classical calculation method as per ISO 5167:2003 is very high and within the specified limits, which shows that no empirical coefficient is necessary for high-accuracy flow metering using the momentum balance.

Barycentric Lagrange interpolation collocation method for solving the Sine–Gordon equation

This paper mainly discusses the numerical solution of Sine–Gordon (SG) equation which is widely used in engineering field. Different from the classical numerical calculation method, we choose the barycentric Lagrange interpolation collocation method (BLICM) to solve the SG equation. Firstly, the barycentric Lagrange interpolation is introduced and its differential matrix is given. Secondly, two linearized iterative schemes namely direct linearized iterative scheme and Newton linearized iterative scheme to solve SG equation are constructed, the matrix equation of the two iterative scheme is obtained. Thirdly, the Newton–Raphson iterative scheme for SG equation is also presented and the detailed solution process is given. Finally, several numerical examples with exact solution are given to show the accuracy of BLICM, the results of three iterative schemes with equidistant nodes and Chebyshev nodes are compared. Further, some examples with line and ring solitons are given to simulate by BLICM, the accurate numerical results are obtained to support our experiments.

Seam Modelling and Reserve Calculation for Lignite Field in Adana-Tufanbeyli (Turkey)

Since the first investment in mining operations is very high, so, it is absolutely important to model the field inthree dimensions for appropriate planning and cost analysis. The whole data set belonging to the geological, geophysicaland drilling exploration studies carried out in the field should be evaluated as a package. In the modelling phase, thecomputer-aided tri-dimensional mining software has been used instead of the classical reserve calculation methods beingutilized in previous years. Thus, more realistic and shorter results are achieved. In the present work, three-dimensionalseam modelling of the Adana-Tufanbeyli (Turkey) lignite field was carried out. In modelling, the coal horizon of thefield was examined. Then, the sub-seam levels in the horizon were determined and after examining their geometricrelationships with each other, three sub-seams were defined. Seam composites were prepared by the downhole methodto make the analysis results of different sizes uniform. It is possible to make block quality estimations, which will be thebasis for reserve calculations, by creating variograms in different directions. Variograms are first created in the verticaldirection and then in the horizontal direction respectively, to obtain the necessary parameters. The nugget effect andstructural distance parameters were obtained from the created variogram models. To assign quality estimation values onthe block model, the Kriging method was used when the number of data was sufficient, and the inverse distance methodwas applied, when it was insufficient. As a result of this modelling study, a total of 355.617.194 tons of lignite reserveswith an average calorific value of 1.153 Kcal/kg were determined in the field.

Energy Efficiency Issues in Buildings: Analysis of World Practice

At present, the volume of world energy consumption is continuously and rapidly increasing, which is a consequence of the industrialization process, population growth, increase in energy costs for the extraction of natural resources, etc. Therefore, the importance of solving the problem of energy efficiency is of paramount importance for modern civilization. In this work, there is an analysis of international experience of energy efficient construction. The main directions of energy-efficient development are highlighted. It’s shown that the classical method of heat loss calculations wrongly takes into account the wind effect. The more correct one is required. At the same time, it is worth applying linguistic variables and fuzzy logic, which adequately describe states that are described by verbal statements, and not by numerical values. In conclusion, the most emerging tasks for our Republic are selected: optimal placement of the building on the general plan of the city, incl. maintaining the distance between buildings under the construction and urban-planning regulations; proper heat insulation of the building envelope by the orientation of facades and depending on the climatic parameters of the outside air; air-tightening of building avoiding in- and exfiltration; maximum possible automation of engineering systems up to integration from smart house to smart city level; modernization and optimization of the operation of engineering systems; maximum use of renewable and secondary (such as exhaust air) energy sources; rejection of the classical calculation method of heat loss estimation, which takes into account the effect of wind speed, and to develop a new methodology.

Analysis of Cross-Bonded Cables Using Accurate Model Parameters

This paper presents a thorough investigation of frequency and electromagnetic transient (EMT) responses of cross-bonded cables. The study adopts newly developed Line/ Cable Data (LCD) Module in an existing EMT-type simulation software. The input impedances evaluated by positive sequence and various mode energizations on a typical cross-bonded cable (CBC) in frequency domain are investigated.In addition to cross-bonded, the solid-bonded cable (SBC) and core-transposed cable (CTC) are analyzed for characteristics of input impedance. The mixed propagation modes of CBC and CTC are studied. The influence of bonding methods and cable models on transient voltages is investigated. The results simulated by the new LCD are compared with the Classical Parameter Calculation (CPC) method and validated by recently proposed extended transmission line (ETL) approach.

Computational-fitting method for mobility extraction in GaN HEMT.

The third-generation semiconductor gallium nitride (GaN) has drawn wide attention due to its high electron mobility property. However, the classical mobility calculation methods such as Hall effect and transfer length method have limitations in accurately extracting the mobility of GaN High Electron Mobility Transistor (HEMT) due to their inability to consider the resistance in non-gate region or their high fabrication costs. This work proposes an effective yet accurate computational-fitting method for extracting the mobility of GaN HEMT. The method consists of measuring the total resistance between source and drain at different gate voltages over a very small range of overdrive voltage variations, when the sum of the transconductance and capacitance of the device is regarded as constants, and fitting a unique function of the total resistance with respect to the overdrive voltage to determine the carrier mobility and the non-gate resistance. The feasibility and reliability of the method has been also verified.

Simulation of hydraulic power matching–based risk and economic evaluation among cascade hydropower stations in spot transactions

The electricity market is evolving rapidly from pre-bid to spot markets, where the transactions between producers and consumers have become crucial and are vulnerable to safety risks. In addition, the new modes of transaction are also becoming popular and are said to have some risks. To reveal the impact of the new electricity transaction mode—spot market—on the safety risk and generation benefit, this article presents a simulation method connecting the transaction results and operation process. To verify the effectiveness of the proposed method, an actual cascade hydropower station (CHS) in the Dadu River basin, Southwestern China, which comprises eight hydropower stations, is selected. Hydraulic power matching among the CHSs is discriminated from four aspects with multiple indicators combined with the reality of a hydropower-dominated market in Sichuan, China. The dispatching decision-making process of hydropower generators is described with a multi-objective optimization model and then solved with a fast search strategy based on the classical output calculation method in hydrology. The security risks and economic damage hidden in the day-ahead market on a certain day are discovered and analyzed. The technology proposed provides support for bidding decisions in spot transactions and satisfies the reality during the transition period of electricity reform.

Evaluation of Metro Station Design in Terms of Normal Operation and Emergency Evacuation Scenarios with 3D Simulation Software

Yaya simülasyonu teknolojilerinin mimarlık ve şehir planlama disiplinlerinde kullanımı yeni bir kavram olmamakla birlikte; makine öğrenmesi tabanlı, insan davranışlarına benzer sonuçlar veren, ajan bazlı, gerçekçiliği ve geçerliliği bilimsel olarak ispatlanmış üç boyutlu simülasyon yazılımları son yıllarda ortaya çıkmışlardır. Bu yazılımlar, özellikle kalabalık ve karmaşık mekanlarda ortaya çıkabilecek sirkülasyon ve acil durum tahliye problemlerinin henüz tasarım aşamasındayken görülmesine olanak sağlamakta; bu sayede yapı inşa edilmeden önce projede gerekli revizyonların gerçekleştirilmesine imkan vermektedir. Ulusal ve uluslararası standartlar doğrultusunda gerçekleştirilen bu çalışmanın amacı, güncel simülasyon teknolojilerinin yapılara ilişkin normal işletme ve acil durum tahliye senaryolarının değerlendirilmesinde kullanımını örnek olarak seçilen gerçek bir metro istasyonu projesi üzerinden incelemektir. Seçilen raylı sistem hattındaki istasyona özgü yolcu yüklerinin bulunması amacıyla klasik elle hesaplama yöntemleri kullanılmış, ortaya çıkan değerler Massmotion yazılımına aktarılarak mekânsal kapasite analizleri gerçekleştirilmiş ve istasyonun tüm katlarına ilişkin hizmet seviyeleri bulunmuştur. Sonuç olarak metro istasyonunun normal işletme ve acil durum tahliye senaryolarının gereksinimlerini karşılayıp karşılamayacağı test edilmiş, ortaya çıkan sonuçlar çalışma kapsamında verilmiştir.

ESTIMATION OF ZAKAT PROCEEDS IN BANGLADESH: A TWO-APPROACH ATTEMPT

The purpose of this study is to calculate Zakat proceeds in Bangladesh by using both classical and contemporary or alternative Zakat calculation methods. The results reveal that the percentage of Zakat amount to GDP is significantly higher than the average, i.e., 2.5-3%; under the classical and alternative approaches, the Zakat proceeds are estimated as 3.79 and 2.33 percent of GDP, respectively.

Математическая модель тягового электропривода колесной пары тепловоза с электрической системой повышения сцепных качеств

A mathematical model of the traction electric drive of a diesel locomotive wheelset has been developed, which allows for theoretical analysis of the increase in coupling qualities when exposed to electric current on the contacts of wheels with rails. For mathematical description of the processes occurring in the electric motor, a classical calculation method is used, which is based on a generalized electric machine. When studying the electric drive, it is not necessary to take into account elastic bonds in the mechanical part, therefore it is presented in the form of a one-mass calculation scheme. The processes occurring in the electric drive system are influenced by various factors. The tangential thrust force, which determines the moment of static load, can have different values determined by resistance to the movement of the train. The greatest traction force depends on reduction of the load on the wheelset in traction mode and on the calculated coefficient of adhesion of the wheels to the rails, which has a non-linear falling character, especially in the zone of low speeds. Contamination of the rolling surfaces of wheels and rails leads to decrease in the physical coefficient of adhesion. The supply of electric current to the contact zones of wheels with rails increases the coefficient of adhesion, the limit values of which in various contact states according to the degree of contamination are described by the corresponding regression mathematical models.

Seam Modelling and Reserve Calculation for Lignite Field in Adana-Tufanbeyli (Turkey)

Since the first investment in mining operations is very high, so, it is absolutely important to model the field in three dimensions for appropriate planning and cost analysis. The whole data set belonging to the geological, geophysical and drilling exploration studies carried out in the field should be evaluated as a package. In the modelling phase, the computer-aided tri-dimensional mining software has been used instead of the classical reserve calculation methods being utilized in previous years. Thus, more realistic and shorter results are achieved. In the present work, three-dimensional seam modelling of the Adana-Tufanbeyli (Turkey) lignite field was carried out. In modelling, the coal horizon of the field was examined. Then, the sub-seam levels in the horizon were determined and after examining their geometric relationships with each other, three sub-seams were defined. Seam composites were prepared by the downhole method to make the analysis results of different sizes uniform. It is possible to make block quality estimations, which will be the basis for reserve calculations, by creating variograms in different directions. Variograms are first created in the vertical direction and then in the horizontal direction respectively, to obtain the necessary parameters. The nugget effect and structural distance parameters were obtained from the created variogram models. To assign quality estimation values on the block model, the Kriging method was used when the number of data was sufficient, and the inverse distance method was applied, when it was insufficient. As a result of this modelling study, a total of 355.617.194 tons of lignite reserves with an average calorific value of 1.153 Kcal/kg were determined in the field.

Development of a methodology of estimating limits of oscillations of optical system of photoelectric rotary encoders

The development of optical sensors with rotating mechanism requires estimation of oscillations limits. Although some work has been done on to linear encoders, there’s no information on such approaches related to rotary encoders. This manuscript proposes a computational approach of estimating oscillations limits of optical systems of rotary encoders. The approach is based on machine computations of waveforms modified by shifting position of one of discs, and rotates not around main axis of optical system. For estimations of oscillations during computations, one of optical discs translated against optical axis of optical system to perform occlusions, accounting differences in light distribution with oscillations presented. As the result of applying of methodology, computer program described and tested to calculate limits of hypothetical optical system, as well as its predictions were confirmed by comparison with behavior of real rotary encoder. This data was achieved with fewer computations, compared to classical calculation methods of light propagation. Developed methodology allows creating computer programs for estimating limits of oscillations within reasonable timeframe.

A detailed multiscale study of rotational–translational relaxation process of diatomic molecules

This article continues our cycle devoted to comprehensive investigation of the diatomic molecule collision process. In this paper, we focus particularly on the in-depth study of the rotational–translational (R–T) energy exchange process and Borgnakke–Larsen (BL) energy exchange model used in the direct simulation Monte Carlo method. The present study, which was performed on several levels of description (molecular, microscopic, and macroscopic), is based mainly on the highly detailed dataset (around 1011 configurations) of binary N2–N2 collisions, obtained via the classical trajectory calculation (CTC) method. This dataset, along with the explicit mathematical representation of the Borgnakke–Larsen model derived in the present paper, allowed us to obtain new results regarding the R–T energy exchange process: (1) we present an ab initio method to derive physically accurate expressions for inelastic collision probability pr in the BL model directly from CTC data; (2) we present a new two-parametric model for pr and compared it to the previously known models, including the recent nonequilibrium-direction-dependent model of Zhang et al. [“Nonequilibrium-direction-dependent rotational energy model for use in continuum and stochastic molecular simulation,” AIAA J. 52(3), 604 (2014)]; (3) it showed that apart from the well-known dependence of the rotational relaxation rate on “direction to equilibrium” (ratio between translational and rotational temperatures), on molecular scale, rotationally over-excited molecule pairs demonstrate almost zero energy transfer to the translational energy mode (even in the case of very significant discrepancies between translational and rotational energies); (4) it was also shown that the Borgnakke–Larsen approach itself may require reassessment since it fails to give a proper description of distribution of post-collision energies. Throughout this paper, we also tried to put together and analyze the existing works studying the rotational relaxation process and estimating the rotational collision number Zrot by performing reviews and assessment of (1) numerical approaches to simulate non-equilibrium problems, (2) models for inelastic collision probabilities pr, (3) approaches to estimate Zrot, and (4) intermolecular potentials used for molecular dynamics and CTC simulations. The corresponding conclusions are given in this paper.

Influence of Support Conditions on Single-Span Profiled Sheet Metal Strength Through Nonlinear FEM Analysis

Profiled sheets are widely used in modern steel structures, either as cladding or as casing in composite structures. Strength calculation of such structures is a crucial design issue, and it represents a complex task because one must deal with thin-walled structures that have complicated cross-section shape. Manufacturers of these structural elements provide data about its strength, mostly based on experimental testing. However, catalogues provide little data about the supporting conditions at the ends that may have influence on structural strength. In this research, the finite element method analysis with geometrical and material nonlinearity and contact analysis in the support zones was applied for the strength calculation of a profiled steel sheet with very high depth. The analysis encompassed determination of the ultimate limit strength and serviceability limit strength with limited deflection. All analyses were conducted for surface load applied over the area of one sheet. Thereat, influence of several factors related to support conditions was considered: friction on the supports, support width, and number of fasteners. Failure mechanisms were also analysed. Obtained results were compared with other sources and methods, like analytical solution, manufacturer’s software, and catalogue data. Results of the research showed that behaviour and strength of those elements depend to the great extent on end support detailing, which cannot be encompassed by classical calculation methods and linear analysis. Significance of the support conditions was proven, and attention was paid on absence of such data in published catalogues.

An Efficiency Study of the Aerodynamic Sound Generators Suitable for Acoustic Particle Agglomeration

The object of this study is the acoustic field generated by aerodynamic acoustic generators of various types and designs. Six types of aerodynamic acoustic generators were studied experimentally and theoretically to determine the parameters of their generated acoustic field. It was established that the aerodynamic Hartmann type sound generator produces the necessary for acoustic particle agglomeration acoustic field and can be used in acoustic air cleaning equipment. It was established that classical theoretical calculation methods underestimate the design features of aerodynamic acoustic generators and cannot be used to calculate their characteristics.