Solving Procedure Research Articles

An analytical model of an eddy‐current coil near the edge of a conductive plate

Truncated region eigenfunction expansion (TREE) method is applied to the analysis of impedance change of a coil in the vicinity of the edge of a metal plate. The analysis is carried out with the second order vector potentials (SOVPs) and provided for both cylindrical and rectangular coils. By full discretisation of the eigenvalues, double series solutions are obtained for the field and coil impedance variations. To simplify the solving procedure further, a novel approach for the determination of eigenvalues is proposed by means of the 1D finite element method (FEM), which is easy to implement and works well for the plate of non-magnetic material. Numerical results for the impedance variations of cylindrical and rectangular coils are compared with those of 3D FEM simulation, by which the efficiency and accuracy of the authors’ method are confirmed, and the former is much faster and more memory efficient.

Testing a Model for the Monitoring of Worked-out Algebra-Problem Examples: From Behaviours to Outcomes on a Math Task

This study aimed at testing an extension of a theoretical model for the metacognitive monitoring mechanism implied in the detection of inconsistencies when the information provided includes abstract symbols in addition to plain text. Ninety-four postgraduates of STEM specialities were asked to read a worked-out algebra-problem example and to report any incoherence, inconsistency, or error detected in the statement or in the solving procedure. A set of model-inspired indexes was defined to describe participants’ behaviour along the task. The Read & Answer software was used to record online individual processing data and participants’ reports. Results supported model predictions. Indexes correctly predicted participants’ outcomes in the task with high accuracy. Specific students’ behaviours could be associated to observed task outcomes with sufficient reliability within the limitations of the study. In addition, algebra processing was compared with plain text processing.

Effects of seepage behaviors on coal spontaneous combustion in longwall gobs: an investigation between Darcy and non-Darcy seepage

Seepage behaviors of air leakage directly affect the coal spontaneous combustion (CSC) in longwall gobs, which is usually regarded as Darcy flow, but in fact, non-linear seepage should better characterize the properties of air flow in the gobs. To address this issue, steady-state percolation tests were conducted on broken rocks with five particle sizes, and the non-Darcy permeability parameters versus porosity and particle size were obtained by binary fitting the experimental data, and then applied to an actual longwall gob. The multi-physics coupling model of CSC in longwall gobs was modified accordingly, which was then validated by comparing with on-site observation data. Numerical solving procedures based on Darcy seepage and non-Darcy seepage were developed separately to quantify the effects of these two types of seepage on the CSC. The results show that (i) the seepage tests confirm that the seepage behavior in the broken rocks is more consistent with the non-Darcy seepage; (ii) the distributions of oxygen concentration and solid temperature under the two seepage flows are relatively similar, but the high-temperature zone in the gob under non-Darcy seepage is larger and hotter; (iii) the non-Darcy permeability coefficient has a positive effect on the coal temperature rise in the gob, while the non-Darcy flow factor has almost no effect, so taking plugging measures at the working face can effectively prevent the spontaneous combustion in gobs. This work contributes to the understanding of the air seepage behavior in longwall gobs and its impact on the CSC.

Wave propagation in carbon nanotube-reinforced nanocomposite doubly-curved shells resting on a viscoelastic foundation

This research aims at studying the propagation of waves in doubly-curved nanoshells made of carbon nanotube-reinforced composite (CNTRC) nanoshell panels while resting on a viscoelastic foundation. For the first time, a nonlocal strain gradient model of first-order shear deformation theory (FSDT) is developed in curvilinear coordinate for the wave propagation analysis of such properties, geometry, and foundation. The effective material properties of four types of CNTs’ distribution are estimated using a modified rule of mixture. The size-dependent governing equations are found using the Hamiltonian principle and after derivation, the equations are solved to find the damped flexural wave responses using a harmonic solving procedure. The results show the influence of viscoelastic foundation parameters, small-scale parameters, CNTs’ distribution schemes, and weight fraction of CNTs on the wave behavior of CNTRC doubly-curved shells with spherical, hyperbolic, cylindrical, and elliptical panels.

An augmented Lagrangian relaxation method for the mean-standard deviation based vehicle routing problem

With the ever-increasing trip demand and limited transportation resource, traffic congestions remain a tricky problem. Under traffic congestions, travel times are unstable and variable in a real-world network. When we conduct many time-sensitive vehicle routing optimizations such as vaccine transportation, it is essential to consider the travel time variability in these optimizations. However, most previous vehicle routing studies neglected the travel time variability and adopted the expected travel times or lengths of links. The historical travel times of multiple days allow us to access and describe the travel time variability. We can easily obtain the travel time means and standard deviations of links from these data. This study applies these two statistical indicators to vehicle routing optimization and concentrates on a mean-standard deviation based vehicle routing model. This model has a nonlinear and concave objective function that dramatically increases the problem complexity. We develop a novel augmented Lagrangian relaxation approach for this problem. A lower bound is constructed for this problem by applying the Lagrangian relaxation and decomposition technique twice. To break the inherent symmetry of this problem, we use the augmented Lagrangian relaxation method with block coordinate descent, linearization, and Lagrangian substitution techniques to achieve high-quality feasible solutions. Thus, the relative gap between the lower and upper bounds can be evaluated and reduced in the solving procedure. We implement the proposed method on the datasets modified from the standard benchmark instances. The average relative gaps of instances in sets A and P are 8.8% and 7.6%, respectively.

Techno-economic analysis of cascaded supercritical carbon dioxide combined cycles for exhaust heat recovery of typical gas turbines

Gas turbine combined cycle is widely used to achieve power balance in grids with uncertain renewable energy sources. To further enhance the rapid load-change capability of combined cycle plants, supercritical carbon dioxide (CO2) has been considered an alternative working fluid for the bottoming cycle. This paper presents a techno-economic investigation of a cascaded supercritical carbon dioxide cycle for typical gas turbines. This cascaded supercritical carbon dioxide cycle consists of a supercritical CO2 cycle and a transcritical CO2 cycle. A solving procedure is originally proposed to compare and optimize the combined cycles in eight gas turbines, whose power output and exhaust temperature ranges were 1.24–113.95 MW and 583–896 K, respectively. The results show that the cascaded supercritical CO2 combined cycle is thermodynamically favorable for small-scale gas turbines with high exhaust temperatures. The variations in the levelized cost of electricity indicate that the combined cycle with a small-scale gas turbine is more sensitive to the operation conditions of the bottoming supercritical CO2 cycle. Regarding the QD128 gas turbine (11.50 MW and 760 K) combined cycle, its multi-objective optimization results show that the optimal solution for techno-economic performance corresponds to a levelized cost of electricity of 0.0420 $/kWh and a net power of 19.701 MW. These findings also suggest that the cascaded supercritical CO2 combined cycle is a viable option for large-scale gas turbines.

Enhancing underwater image via adaptive color and contrast enhancement, and denoising

Images captured under water are often characterized by low contrast, color distortion, and noise, hindering some visual tasks carried out on it. Despite remarkable breakthrough has been made in recent years, effective and robust enhancement of degraded image remains a challenging problem. To improve the quality of underwater images, we propose a novel scheme by constructing an adaptive color and contrast enhancement, and denoising (ACCE-D) framework. In the proposed framework, Difference of Gaussian (DoG) filter and bilateral filter are respectively employed to decompose the high-frequency and low-frequency components. Benefited from this separation, we utilize soft-thresholding operation to suppress the noise in the high-frequency component. Specially, the low-frequency component is enhanced by using an adaptive color and contrast enhancement (ACCE) strategy. Moreover, we derive a numerical solution for ACCE, and adopt a pyramid-based strategy to accelerate the solving procedure. Both qualitative and quantitative experiments demonstrate that our strategy is effective in color correction, contrast enhancement, and detail revealing. In the quantitative evaluations, by performing on the 890 real-world underwater images from UIEBD, the proposed method obtains 0.65 UCIQE, 1.59 UIQM, 0.81 FDUM, 1.34 PCQI, 0.62 CBPD, and 7.75 entropy scores, achieving average increase of 5% comparing with several state-of-the-art methods. Furthermore, we have verified the utility of our proposed ACCE-D for enhancing other types of degraded scenes, including foggy scene, sandstorm scene and low-light scene.

Implementasi Algoritma Dijkstra Rute Terpendek pada Aplikasi WisKul PasMing

Indonesia is famous for its various kinds of culinary tourism and spread in various areas of the city of Jakarta. Various types and locations of culinary make it difficult for local and foreign tourists to find and choose culinary dishes and the routes to culinary locations in Jakarta are very numerous and varied, especially foreign tourists. Therefore, the author tries to make an android-based culinary tourism location search application in the hope that it can provide a lot of culinary location information with the fastest and closest tracks, and is equipped with a map of culinary tourism locations. The algorithm used to find the shortest track uses the Dijkstra algorithm. The Dijkstra algorithm is a search algorithm for the shortest track based on the smallest track (edge) from the implementation location to the destination culinary tourism location. Culinary tourism area data and road data obtained from Google Earth and Google maps. From the origins of the trial of instances which have been done, it could be visible that the application has succeeded in implementing the Dijkstra solving procedure in finding the shortest route to culinary locations. This study produces the following distance node values BCDEJIF, ABCDFGHINM, MNIFDCBAE, BAEJNMLKHG, ABCDFGHIJE ABCDFGHILM, ABCGHKLMNIJE.

Nonlinear analysis of two-degree of freedom system with nonlinear springs

In this paper, an analytic solving procedure for a two degree of freedom oscillatory system (2DOF) is considered. Vibration of the two-mass system is mathematically modeled with two coupled second-order equations. The system is assumed to be strongly nonlinear, and a high order Homotopy Perturbation Method (HPM) for solving the system is developed. The frequency of vibration is obtained in the second approximation. To validate the method, two examples are considered. The solutions of the HPM are compared with those of Newton–harmonic balance (NHB) and numerical approaches. It has been demonstrated that HPM leads to a highly accurate solution even with the first iteration of the solution and is valid for a wide range of vibration amplitudes, showing promise as a means to provide an exact or closed-form solution of nonlinear dynamical systems, as indicated in the following examples.

Penerapan Metode Dijkstra Pada Jalur Distribusi LPG Untuk Penentuan Jarak Terpendek

Determining a shortest path is a crucial and necessary thing in connection with optimizing the time used and some savings in other fields. This research aims to design a software for determining the shortest distance on a web-based LPG gas distribution line by applying the Dijkstra solving procedure at PT. Amartha Anugrah Mandiri. This study uses the SDLC (software development life cycle) development method using waterfall modeling, to determine the closest route during the distribution of LPG gas using the Dijkstra solution procedure, namely by determining which location is used as the initial node, then set the distance value at the initial node to neighboring nodes. the closest one by one. The results of this study make it easier for drivers to find the closest route that can be passed to the base location. Dijkstra's solving procedure in the software for determining the shortest distance in the PT. Amartha Anugrah Mandiri can form the shortest distance traveled to get to the base

Analysis of Mathematics Problem Solving Ability of Junior High School Students in Solving Problems in Online Learning

This study aims to determine the mathematical problem solving ability of students in solving story problems with online learning. The method in this study used a qualitative descriptive research method. The results showed that there were differences in the ability to identify the elements that were known and asked, there were differences in the ability to choose and apply strategies or problem solving procedures and there were differences in the ability to examine and explain the results or answers according to problems between students with high, medium mathematical problem solving abilities. and low. There are 43% of students who have been able to follow and adapt online learning while 57% of other students have difficulty understanding the material being taught. There are 60.86% of students who have a high enough enthusiasm in online learning (online) but 39.13% of students are not happy if learning mathematics is done online due to factors that influence it such as technical constraints. There are 73.91% of students with a positive response to the problem of mathematical problem solving ability even though the learning is carried out online and 26.08% of students with a negative response.

Assessing computational thinking in the social studies

ABSTRACT Although computational thinking has most often been associated with the science, technology, engineering, and math education fields, our research takes a first step toward documenting student outcomes associated with integrating and assessing computational thinking in the social studies. In this study, we pursued an embedded research design, merging teacher action research with qualitative case study, into collaborative inquiry. Through analysis of classroom-based data, including samples of student work, we were able to develop an understanding of the manner with which student understanding of computational thinking emerged in this classroom. Findings suggest that, through the integration of carefully designed learner-centered tasks, students came to view computational thinking as computer mediated data analysis or an approach to analyzing data and solving problems. The iterative nature of the instructional design—three consecutive units built around the same heuristic of data-patterns-rules—as well as the variety of learning-centered tasks given to students, appeared to have enabled the teacher and students to have a common set of procedures for problem solving and a common language to articulate the goals and outcomes of data analysis and interpretation. Our study demonstrated that framing a lesson through the lens of computational thinking provides teachers with strategies for engaging students in a structured, yet authentic approach to grappling with complex problems relevant to the subject.

Dynamic response analysis of vehicle and asphalt pavement coupled system with the excitation of road surface unevenness

This study aims to solve the dynamic responses of the vehicle and asphalt pavement coupled system while considering road surface unevenness and deformation. First, an advanced solving procedure is proposed by decoupling the vehicle-pavement coupled system into two subsystems (i.e., quarter vehicle model with two degrees of freedom, and viscoelastic multilayered asphalt pavement) and solving them independently until the surface deformation has converged through an iterative scheme. During the solving procedure, the finite difference method and integral transform techniques are respectively conducted to compute the dynamic responses of vehicle and pavement. Then, the solutions for the dynamic responses of the pavement are verified through finite element simulation, which highlights the accuracy and efficiency of the proposed solution. The convergence study for the iterative procedure of vehicle-pavement coupled system is conducted, and the coupling effect on pavement and vehicle displacements is investigated. Finally, the effects of the vehicle and pavement parameters (i.e., suspension stiffness and damping, tire stiffness and damping, road surface unevenness, and pavement temperature and vehicle speed related to the viscoelasticity of asphalt material) on the pavement dynamic responses and damages are discussed comprehensively. These numerical investigations could prove that the solutions for the dynamic responses of the vehicle-pavement coupled system has the potential to guide road-friendly vehicle design and pavement service life evaluation.

On the Semi-Analytical Solutions in Hydrodynamics of Ideal Fluid Flows Governed by Large-Scale Coherent Structures of Spiral-Type

We have presented here a clearly formulated algorithm or semi-analytical solving procedure for obtaining or tracing approximate hydrodynamical fields of flows (and thus, videlicet, their trajectories) for ideal incompressible fluids governed by external large-scale coherent structures of spiral-type, which can be recognized as special invariant at symmetry reduction. Examples of such structures are widely presented in nature in “wind-water-coastline” interactions during a long-time period. Our suggested mathematical approach has obvious practical meaning as tracing process of formation of the paths or trajectories for material flows of fallout descending near ocean coastlines which are forming its geometry or bottom surface of the ocean. In our presentation, we explore (as first approximation) the case of non-stationary flows of Euler equations for incompressible fluids, which should conserve the Bernoulli-function as being invariant for the aforementioned system. The current research assumes approximated solution (with numerical findings), which stems from presenting the Euler equations in a special form with a partial type of approximated components of vortex field in a fluid. Conditions and restrictions for the existence of the 2D and 3D non-stationary solutions of the aforementioned type have been formulated as well.

AN OPTIMAL POWER DISTRIBUTION SCHEME FOR THE DENSE NETWORK COMPOSED OF 5G BASE STATIONS BASED ON VIRTUAL ENERGY BACKUP

As the digitalization is sweeping the world, the amount of DC load increases tremendously, among which the dense networking of 5G base station is a typical example. This paper firstly analyses the demand of 5G network and the difference between its 4G counterpart, then aiming at minimizing the station backup energy and hence the operating cost of telecommunication company, this paper proposes the DC power feeding scheme and integrates the concept of virtual energy backup (VEB), i.e., by connecting the 5G stations and energy storage to the DC network, the centralized energy storage act as an energy backup to the distributed 5G stations. For the operation of the 5G power feeding network with VEB, this paper proposes the multi-objective power flow (MOPF) model and implemented a solving procedure. The benefit of the proposed scheme is demonstrated by a full day simulation, and the result shows a very good energy and cost saving. The study has the extensive applicability and practical significance to both the research and construction of 5G dense network.

A hybrid learning-based meta-heuristic algorithm for scheduling of an additive manufacturing system consisting of parallel SLM machines

Additive manufacturing (AM) has been recognised as a promising technology under the context of Industry 4.0, which is reshaping manufacturing paradigms. A prominent type of AM machine is the selective laser melting (SLM) machine, in which several parts may form a job and be produced concurrently. This paper aims to investigate a scheduling problem in an AM system with non-identical parallel SLM machines. Since, in this system, there might be differences in the material types of parts, the required setup time between two consecutive jobs on the relevant machine is dependent on their material types. Accordingly, a bi-objective mathematical model is extended for the problem, considering the makespan and the total tardiness penalty as two objective functions. Due to the high complexity of the problem, an efficient hybrid meta-heuristic algorithm is developed by combining the non-dominated sorting genetic algorithm (NSGA-II) with a novel learning-based local search founded on the k-means clustering algorithm and a regression neural network. The local search enhances the exploitation ability of the NSGA-II while intelligently being taught during the solving procedure. Finally, the superiority of the proposed hybrid algorithm is demonstrated through a computational experiment.

AL-QUR'AN INSIGHTS ABOUT KIZB

This research is related to the comprehensive view of the Qur'an about kiz|b, the discussion focuses on matters related to kiz|b, namely the essence of kiz|b: definitions and terms that are relevant in meaning to kiz|b either directly or indirectly. , explicitly or implicitly designated by the Qur'an, including, subject, object, motive and impact This research is (library research), intended to obtain data and information, literature in the form of books, notes and reports of scientific research that done before. These written data were then analyzed qualitatively. This is done because this research departs from the exposure of research data in the form of verses of the Qur'an, then put forward various interpretations related to the verse referred to by using various approaches. Then this research will offer a theory about the insight of the Qur'an about kiz|b. This type of research is classified as descriptive qualitative research, which can be interpreted as a problem solving procedure that is being studied by carefully describing or describing the state of the object of research. This descriptive research is a method designed to collect data and information whose main purpose is to provide a clear picture of the nature of a situation. Because this research is descriptive, it is not intended to test existing theories, but is directed to develop theories and ideas related to الكذب which can be interpreted as a problem solving procedure that is being studied by describing or describing the state of the object of research carefully. This descriptive research is a method designed to collect data and information whose main purpose is to provide a clear picture of the nature of a situation. Because this research is descriptive, it is not intended to test existing theories, but is directed to develop theories and ideas related to الكذب which can be interpreted as a problem-solving procedure that is being studied by carefully describing or describing the state of the object of research. This descriptive research is a method designed to collect data and information whose main purpose is to provide a clear picture of the nature of a situation. Because this research is descriptive, it is not intended to test existing theories, but is directed to develop theories and ideas related to الكذب في الان al-kiz|b fi al-Qur'an Insight of al-Qur'an about Kiz|b, the approach in question is the approach to the science of interpretation, namely the science by which an understanding of the Qur'an is obtained. This research data comes from a lot of literature, so this research uses documentary data collection techniques, namely finding and collecting data sourced from written sources such as primary and secondary data obtained from the Qur'anic manuscripts, hadith books, interpretation books and other literature related to the discussion of research, the object of this research is the verses of the Qur'an about al-Kiz|b whose data is classified as qualitative data, then the data is analyzed using content analysis techniques.

Rotating vector solving method applied for nonlinear oscillator

Significant number of procedures for solving of the finite degree-of-freedom forced nonlinear oscillator are developed. For all of them it is common that they are based on the exact solution of the corresponding linear oscillator. For technical reasons, the aim of this paper is to develop a simpler solving procedure. The rotating vector method, developed for the linear oscillator, is adopted for solving of the nonlinear finite degree-of-freedom oscillator. The solution is assumed in the form of trigonometric functions. Assuming that the nonlinearity is small all terms of the series expansion of the function higher than the first are omitted. The rotating vectors for each mass are presented in the complex plane. In the paper, the suggested rotating vector procedure is applied for solving of a three-degree-of-freedom periodically excited oscillator. The influence of the nonlinear stiffness of the flexible elastic beam, excited with a periodical force, on the resonant properties of the system in whole is investigated. It is obtained that the influence of nonlinearity on the amplitude and phase of vibration is more significant for smaller values of the excitation frequency than for higher ones.

Mass Loss and Penetration Depth of Hypervelocity Projectiles

Numerous investigations recorded a dramatic decrease in penetration depth at hypervelocity. The decrease is due to the severe mass loss of the projectile. The mechanics of mass loss are complicated, so the entirely theoretical model is still absent. In this paper, we derive a semitheoretical formula for mass loss by solving the equation of motion of the projectile during penetration. The result shows that the decrease in projectile mass at hypervelocity accords with the power law. Furthermore, we obtain a continuous formula for depth of penetration in the entire velocity domain. The theoretical results agree well with experimental data. The formula for the critical velocity of depth decreasing is also obtained as a by-product of the solving procedure.

Wave propagation in thermoelastic inhomogeneous hollow cylinders by analytical integration orthogonal polynomial approach

A new solving procedure based on the Legendre polynomial series is developed to investigate the longitudinal guided waves in fractional order thermoelastic inhomogeneous hollow cylinders. Different from the available Legendre polynomial approach, integrals are calculated by the explicit and simple expressions to replace the numerical solutions. The solutions according to the global matrix method (GMM) are also derived for the first time to verify the effectiveness of the presented approach. Comparison of the CPU time indicates that the computational efficiency of the new solving procedure has a huge improvement. Then, the guided wave phase velocity dispersion curves, attenuation curves, displacement and temperature distributions for functionally graded hollow cylinders with different fractional orders, flexural orders, radius-thickness ratios and gradient fields are analyzed. It is found that the attenuation coefficients of flexural longitudinal modes rapidly decrease when the flexural torsional mode curve is close to the flexural longitudinal mode curve. Furthermore, notable influence of the flexural order on attenuation curves mainly occurs at the cut-off frequencies and mutation frequencies. In addition, a smaller radius-thickness ratio implies a larger attenuation, and the temperature amplitudes of flexural torsional mode are more and more close to those of longitudinal mode when the radius-thickness ratio decreases.