Search

The paper presents the numerical simulation of thermo-hydraulic behaviour of coolant in nuclear reactor VVER-440 under major outage conditions. Heating-up and the flow of coolant between the reactor pressure vessel and spent fuel storage pool are discussed. [ABSTRACT FROM AUTHOR]

Prosthesis has been advancing since the day of its introduction, having a tremendous degree of advancement and examination in clinical field as well as in robotics. This has been an influence for researchers who made it conceivable with various types of prosthetics that are accessible these days in the market both commercially and uniquely crafted. This paper throws light on numerical simulation and design of a prosthetic leg. The work focuses on the optimization and simulation of a prosthetic leg, improving its strength and making it cost effective. The paper has described the design and analysis of two early-existed models of prosthetic leg, comparing their strength and durability through different material analysis and thereafter designing a new model with better strength, having a high deformation rate or durability, and having much cost-efficient design and material. The Finite element analysis (FEA) was done in Ansys software, the material properties and cost efficiency were kept in mind during the analysis as well as during selection of material. Prosthetics are modified for every person, remembering the utilization and actual properties. In any case, the conventional prosthetics are heavier, and the production is costly andtedious. The current study resolves this issue and proposes an elective plan for prosthetic legs. The designed prosthetic was simulated properly and has been compared with earlier existed models. The study concludes that the new design is much more efficient and user friendly that the wearer will feel comfortable, to live a normal life. [ABSTRACT FROM AUTHOR]

Electroplated plastic parts are mainly produced by injection molding of acrylonitrile butadiene styrene (ABS) or polycarbonate/acrylonitrile butadiene styrene (PC/ABS). However, polyamide (PA) has superior physical properties, but the coating quality is inferior leading to higher scrap rates up to 30 %. Besides the electroplating parameters, the coating quality depends on the surface of the injection molded part. Former published experimental investigations and analysis of three-dimensional surface key figures according to DIN EN ISO 25175 showed that injection molding parameters significantly influence the surface layer of the produced mineral-filled polyamide parts. The aim of this paper is to present causes for the differences in the surface structure of mineral-filled polyamide. Therefore, a Design of Experiments (DoE) is carried out using 3D injection molding simulation software to determine effects that cannot be measured in the real process. The results of shear rate, temperature and degree of crystallization are evaluated at four different positions on the plastic part. Furthermore, the results are related exemplarily to the height parameter Sa of the real experiment. [ABSTRACT FROM AUTHOR]

In the paper the cancellation phenomenon in bridge beams influenced by high traffic speed on high-speed railroads is discussed. The Euler-Bernoully beams model in combination with partial equations for beams and ordinary equations for a train were used. Multiple intermediate resonance which may occur in case of active vibration control makes the cancellation phenomenon not only useless but even harmful because of different speed of trains. Nevertheless, the computer simulation does not detect the multiple resonance at the speed value that is predicted by train signature method. [ABSTRACT FROM AUTHOR]

Soft Computing will be primarily accustomed give solutions to real-world problems, that aren't modelled or too tough to model mathematically. during this planned paper, an in-depth survey of varied procedure techniques like Genetic algorithmic rule and K Nearest Neighbors employed in the care trade Health diseases are included for prediction. The computer model moon-faced problems are known but health and also future analytical directions are given to predict and predict health conditions. [ABSTRACT FROM AUTHOR]

The application of complex nonlinear material models of concrete within the numerical simulations is currently the most used way for the purposes of modeling the nonlinear computer response of concrete structures. However, the modeling of nonlinear concrete behavior through the nonlinear material models very often brings with it the major problem. This problem can be specified as a user nescience of a large number of material model parameters which is very common. Nowadays, the solution of this problem is possible with the so called inverse analysis or identification which can be performed via the different methods and approaches. One of the most effective approach for the purposes of the inverse analysis is currently using the combination of sensitivity analysis with optimization algorithms. This mentioned approach is demonstrated within this paper in which the parameters of the material model called the Continuous Surface Cap Model are identified. Material parameter identification is performed on the basis of interaction between nonlinear numerical simulations, statistical and optimization methods and experimental data which are represented by a load-extension curve obtained from the unconfined uniaxial tensile (UUT) test. The final comparison of the experimental data with the numerically-simulated data for optimal parameter values is, of course, also part of this paper. [ABSTRACT FROM AUTHOR]

Quantum technology is a candidate for the sixth generation of telecommunications (6G) in 2030. This paper proposes a new quantum coding scheme in the class of Calderbank-Shor-Steane (CSS) codes based on the Reed-Muller codes, since Reed-Muller codes are one of provably classical Shannon Capacity achieving codes. This paper keeps the proposed new codes simple by making dual-containing CSS codes having Hx = Hz, such that no further search is required for Hx or Hz. The proposed quantum Reed-Muller codes are designed from the classical Reed-Muller codes with puncturing to obtain new codes with block-length of n = 7 qubits capable of error correcting t = 1 qubit error and quantum information of k = 1 qubit, of which the extension to other block-lengths are expected to be straightforward. This paper performs a series of computer simulations to evaluate the quantum word error rate (QWER) performances under the depolarizing channels. The proposed quantum Reed-Muller codes satisfy the stabilizer codes requirement, where the diagonal element of symplectic inner product (SIP) is kept zero to guarantee a successful error correction. The proposed codes have a structure with a length close to that of the perfect quantum codes. Our results confirm that the stabilizers of the proposed codes can extract the syndrome and distinguish all error patterns of any single qubit error. This paper also confirm that the simulated performances are agreed by the theoretical QWER performances indicating that the both coding design and simulation environment are correct. These results confirm that the classical Reed-Muller codes can be used directly as QECC by puncturing the parity check matrix H. The results of this paper are expected to open new ground on the invention of new quantum codes derived from the classical codes. [ABSTRACT FROM AUTHOR]

For the design of feed sections in single-screw extruders, analytical methods are increasingly being replaced by numerical methods. One possibility for numerical process modeling of solids conveying is offered by the discrete element method (DEM), which is able to calculate individual particle movements and interactions. With DEM it is possible to determine quantities that are difficult to measure and get insight into physical processes. In this paper, dissipation in the solids conveying section is calculated with the help of DEM, since conventional analytical methods until to now are not able to provide precise results due to the complexity of the pellet movement. A specific analysis of the possibilities for dissipation calculations in the solids conveying section is carried out with the software EDEM. Two fundamentally different approaches are compared. On the one hand, the temperature increase is simulated directly via a user-defined contact model, on the other hand, an average temperature increase is calculated indirectly via a macroscopic energy balance. The description of dissipated energy as a result of friction is particularly important as it leads to a direct increase in the temperature in the solids conveying section. For a correct screw design, knowledge of the temperature in this section is essential, as melting of the material inhibits effective solids conveying. Therefore, this paper focuses on the determination of the quantities of the friction work and the resulting temperature. [ABSTRACT FROM AUTHOR]

To assess the potential capabilities of computer systems (CS), indices of the realizability of solving tasks are used. These indices characterize the quality of the systems, taking into account the reliability of the CS and the parameters of the tasks. These estimates become relevant when scalable computer systems are considered. For example, 93% of the TOP 500 supercomputers are cluster-type systems that are scalable. Failures in such systems, which directly depend on the number of computing nodes, significantly reduce the efficiency of solving tasks. The paper presents a description of mathematical model of computer systems with accumulator in group servicing task flow. The mathematical model is based on the methods of queuing theory. The paper offers solutions for calculating indices that allow us to assess the fullness of the accumulator and understand how the size of the group affects the fullness of the one. The obtained analytical solutions are aimed at express analysis of the functioning of CS. [ABSTRACT FROM AUTHOR]

In the recent few years, ICT Tools are popular in education to increase student's knowledge and interest. There is still lack of awareness of what kind tools are available. This paper presents a review of some applications/tools used for educational purposes and to improve student's educational growth and knowledge especially for computer engineering students. In this digital world, tools like animation, polls, quizzes, etc. are very amazing thing to include as part of subject activity. We wrote in this paper about different ICT tools along with their pros and cons to help faculties to decide the type of tool they can embed with their teaching learning methodologies according to their subject need. [ABSTRACT FROM AUTHOR]

NORM (Naturally Occurring Radioactive Material) and TENORM (Technologically Enhanced Naturally Occurring Radioactive Material) were introduced in Government Regulation No. 33 Year 2007 as part of the chronic exposure situation. The supervision on NORM and TENORM has changed in recent years. Despite the dynamics of development during this period, the focus of supervision is concentrated minerals contain radioactive. This paper aims to identify the concept of dose assessment in the supervision of radioactive concentrated minerals. The methodology used in this paper is a literature study of regulations, international recommendations, and practices from the other countries. The activity concentration of uranium and thorium decay series, and potassium remains the main basis for supervision. The practice of Australia and Malaysia, as well as the IAEA recommendations use the concept of a graded approach. The activity concentration as a basic starting point for the next assessment process. Dose assessment means an assessment of an individual or group of people. Dose assessment should take into account the various possible exposure pathway scenarios from the source to the receptor. The exposure pathway and number of exposure scenarios depends on the variety of scenarios from location and operation/activity. Some of these variations will provide a level of difficulty in developing exposure scenarios. Dose assessment can be done by comparison of measured radionuclide concentrations to reference levels, spreadsheet analysis using dose coefficient tables, or computer modeling. [ABSTRACT FROM AUTHOR]

The paper focuses on the construction of information models for the technical energy systems' functioning. This is an urgent problem that arises in applications when describing the dynamics of systems of the input-output type. Constructive algorithms for solving typical inverse problems arising when evaluating the reliability of power systems are implemented. The scientific novelty of the work is due to the use of new methods based on nonclassical Volterra integral equations of the first kind as applied to the identification and automatic control problems in describing the nonlinear dynamics of technical equipment of a large electric power system. The results of a computational experiment are presented. They confirm the accuracy of the developed computational algorithms, sufficient for practical application. [ABSTRACT FROM AUTHOR]

The paper presents the results of numerical simulation of the development of localized disturbances from two synchronous sources in the laminar boundary layer of the flat plate at the flow Mach number M = 2. The calculations were performed using the FlowVision software package. Modeling was carried out at flow parameters typical for ADT-325 ITAM SB RAS. The fluctuations of the boundary layer formed from two sources are compared with the case of a single source. It is found that the amplitude and spatial scales of the disturbance from two sources are greater than in the case of a single source. [ABSTRACT FROM AUTHOR]

The paper presents the step by step process of modelling the movement of dispersed group of mobile robots using the MATLAB Simulink and Simscape Multibody software. As a modelled object, a group of laboratory robots, TurtleBot2, was adopted. First, the construction of a robot CAD model was described. Next, the control system developed in Simulink was described. At the end, the robot components were defined in Simscape Multibody and a group movements analysis was carried out [ABSTRACT FROM AUTHOR]

This paper is aimed to discuss and compare three of the most famous Control Theories on a Two wheeled Self Balancing Robot Simulation using Robot Operating System (ROS) and Gazebo. Two Wheeled Self Balancing Robots are one of the most fascinating applications of Inverted Pendulum System. In this paper, PID, LQR and Fuzzy logic controllers are discussed. Also,0 the modeling and algorithms of the robot simulation is discussed. The primary objectives of this paper is to discuss about the building of a robot model in ROS and Gazebo, experimenting different control theories on them, documenting the whole process with the analysis of the robot and comparison of different control theories on the system. [ABSTRACT FROM AUTHOR]

The present paper investigates the multi-dimensional case of the cubic mappings. We have investigated the properties of Mandelbrot and Julia sets for the two-dimensional case of the mappings on the plane to itself. Mandelbrot and Julia sets help to define asymptotical behavior of the trajectories. The analytical solutions of the equations for finding fixed points and the computer simulations for describing Mandelbrot and Julia sets are the main results of this paper. [ABSTRACT FROM AUTHOR]

This paper proposes the modulating functions approach for identifying coefficients in the sixth order generalized Boussinesq equation. The identifiability of the estimation problem is studied. Numerical simulations are given to demonstrate the efficiency and robustness of the proposed method in both noise-free and noisy cases. [ABSTRACT FROM AUTHOR]

This paper discussed the transmission dynamics of discrete SEIR model. It is possible to determine the prerequisites for the endemic and disease-free equilibria, as well as their local stability. In addition to demonstrating the validity of our findings, the numerical simulations also display more sophisticated dynamical characteristics such as the chaos phenomena, flip bifurcation, and Hopf bifurcation. These findings demonstrate that, as compared to models for both continuous and discrete epidemics exhibits far richer dynamical features. [ABSTRACT FROM AUTHOR]

Abstract. In this paper, a prey, predator and apex predator food 4chain model4 is proposed and analyzed. The model includes the impact of fear on solution dynamics. All feeding processes in this ecological model are formulated in terms of Crowley-Martin-like functional responses. The primary goal of this work is to find the existence condition, uniqueness and boundedness of the solution. The second goal is to study the local and global stability of these solutions. Finally, the analysis results are verified by numerical simulation. [ABSTRACT FROM AUTHOR]

The paper discussed the problems related to a linear quadratic regulator (LQR) synthesis for the control implementation in a semi-active car suspension. The control is a combination between the state's feedback and compensation by the excitation. For this purpose, the state and the input disturbance are reconstructed using the observed variables. The physical nonlinearities of the controllable magneto-rheological semi-active damper are considered. The regulator structure also includes a model of the inverse magneto-rheological damper, based on neural networks. A "Quarter car model" is used for the vehicle suspension modelling as enough adequate and appropriate for real-time control. The main contribution of the research is the approach for determining the weight matrices of the regulators, based on a formulated multicriteria problem, and solved based on the Game Theory. Numerical simulations are given, allowing for comparison of the results, and confirming the effectiveness of the presented approach. [ABSTRACT FROM AUTHOR]

Additive technology (AM) using selective laser melting (SLM) is widely used to produce parts with complex shapes made of metal alloys, composites and ceramics. One of the main problems of SLM is ensuring dimensional accuracy. The paper presents the study of the influence of selected parameters of the SLM process, such as laser power, scanning speed, distance between tracks, powder layer thickness and volumetric energy density on the dimensional accuracy of the product. The mathematical model was obtained based on a dimensional analysis describing the dependence of the SLM process parameters on the dimensional deviations of the product. Computer simulation of the SLM process was carried out using COMSOL Multiphysics® software. Theoretical results were verified experimentally on Cr-Co alloys. [ABSTRACT FROM AUTHOR]

The paper analyzes the influence of the adaptive mechatronic system parameters on the process of stabilizing the step of moving materials during automatic assembly. Dependences of variances and mathematical expectations of the displacement step are obtained depending on the parameters of the system under a random external action. Numerical simulation of the operation of the algorithms used is carried out, recommendations are given for the optimal choice of system parameters. [ABSTRACT FROM AUTHOR]

In this paper, a system of nonlinear partial differential equations describing the spread of viruses in computers has been solved using the Exp-Function method, studying the solution for these types of systems helps to mitigate the effects of viruses by predicting their occurrence, in addition to that, the effect of parameters on the behavior and spread of viruses is studied. Figures are present to illustrate the effect of parameters in solving the nonlinear system. [ABSTRACT FROM AUTHOR]

Numerical simulations of various welding process have been investigated by researchers in the past few decades with the advent of faster computation power becoming more and more assessable. Since the welding process involves high temperatures, a coupled thermal- structural simulation becomes imperative for analyzing the post welding effects like residual stresses etc. This paper investigates various approaches, including element types, solver settings etc. and correlates the results with experimental data. The analysis of transient thermo- structural simulation was carried out for butt weld of structural steel material and both temperature and strain fields were calculated for various heat inputs and heat input rates. These results were used for a parametric study for optimization of process parameters using inbuilt optimizer. [ABSTRACT FROM AUTHOR]

Tall buildings are mostly sensitive to wind load and the effect of wind varies with respect to height, location, shape of the structure, and hence it important to calculate the actual wind loads on tall buildings. This paper investigates the effect of wind over a square building and square building with twist 45°. The stimulation is carried using Computational Fluid Dynamics (CFD) available in ANSYS Fluent software. Turbulence model k-ε is used to simulate the external flow. The building stimulation is done at a 0ͦ winf angle. The result such as wind pressure distribution on various faces of the building is obtained and hence the result proves that aerodynamically modified building shapes can help to reduce the wind load on tall buildings. Further, this paper externs in identification wake regions, flow patterns of the wind and their behaviour around the building. [ABSTRACT FROM AUTHOR]

Mufflers represent devices used to reduce sound and pulsations for internal combustion engines and other equipment like volumetric compressors. Depending on application they are designed to reduce low, medium or high frequency pulsations. The main design is represented by acoustic filters which use the acoustic analogy method. Dealing with low frequency pulsations this type of filters result in bulky constructions. The use of metamaterials results in a more compact design for these type of mufflers. This paper investigates by numerical simulations the transmission loss (TL) of such muffler based on acoustic black hole (ABH) metamaterial principle. In the first part of the paper the FEM results are compared with the acoustic measurements performed on an adapted impedance tube, in order to validate the model. In the second part the influences of the geometric parameters (length of the muffler, lamellae depth and thickness) will be investigated. The comparative analysis between the FEM and the measured results indicates good agreement. The geometric parameters analysis highlighted that the acoustic attenuation can be increased by using a long muffler. [ABSTRACT FROM AUTHOR]

St12T steel (X22CrMoV12-1) is characterized by high resistance to deformation, including the ability to withstand mechanical loads at high temperatures above 550 °C, which justifies its widespread use in turbine components. The main aim of the paper is determination of the model material coefficients for steel St12T after termo-mechanical exploitation. For this purpose it has been carried out termo-mechanical compression test. Afterwards the termo-mechanical compression test was repeated using tools CSD (Computational Solid Dynamics) in a numerical simulations. In the present simulation a modified Chaboche viscoplasticity model with hardening has been used. In the paper it is shown simulation of the experimental probe with a cylindrical shape, distributions of temperature, analyzed the status of the stress effort and plastic strains. The results of simulation compared with chart from termo-mechanical test is presented. [ABSTRACT FROM AUTHOR]

The paper uses three-dimensional quasi-steady molecular statics nanocutting model to perform simulative cutting of single-crystal silicon. The study is different from the past literature that those papers mostly used molecular dynamics (MD) to perform simulation of nanocutting. Regarding the simulated cutting of single-crystal silicon performed by the paper by using the nanoscale cutting model of three-dimensional quasi-steady nanoscale molecular statics method, it is a concept that the method of calculating the movement track of each atom is used to directly acquire the applied equilibrium force when each atom moves for a small distance. The paper uses optimized method to solve the equation of equilibrium force, find out the new movement position, and step by step calculate the cutting behavior in times of cutting. In order to prove the feasibility of the paper's use of three-dimensional quasi-steady molecular statics nanoscale cutting model of single-crystal silicon, the paper simulates a diamond cutting tool with rake angle at 30 degrees, being the same as Komanduri's , to conduct orthogonal cutting of single-crystal silicon workpieces at a width of two single-crystal silicon lattices and a width of four single-crystal silicon lattices. The simulation result is compared with the numerical value obtained by Komanduri. The error between them is found to be within an acceptable range, proving that the paper's simulative model of three-dimensional quasi-steady molecular statics nanoscale orthogonal cutting of single-crystal silicon is feasible. Besides, the paper not only discusses the cutting force and cutting behavior, but also analyzes the distribution of nanoscale equivalent stress and equivalent strain at the middle cross-section of silicon workpiece in orthogonal nanocutting process. [ABSTRACT FROM AUTHOR]

Prediction of ship hydrodynamic derivatives is essential to evaluate ship's maneuvering capabilities. In this paper, static drift simulation results are shown for a very large crude carrier ship model, KVLCC2. For simulation, a RaNS based solver, SHIP Motion, was used. The solver solves overset structured mesh using finite volume method. The simulation results were compared with experimental data. Next, linear hydrodynamic derivatives were predicted from simulation results and compared with experimental ones. The results show good agreement with experimental data and the paper concludes that the solver, SHIP Motion, is well capable to estimate hydrodynamic derivatives maintaining reasonable accuracy and economics. [ABSTRACT FROM AUTHOR]

Curve reconstructions are widely been used in reverse engineering problems. The reverse engineering process is the creation process of computer model from its original real-life model or its prototypes. The purpose of the reverse engineering is to improve the visualization of two-dimensional data from a series of data point. This paper presents a curve fitting of cubic Bézier curve with parameter optimization by using Differential Evolution. In this research, differential evolution algorithm is used to optimize the parametric value t associated with each point so that the distance between the original images and the parametric curve is minimize. In addition, Sum Square Error (SSE) has been used to calculate the distance between the original images and the parametric curve. The proposed technique that we used in this paper provides the comparison of numerical result to solve curve fitting problem. [ABSTRACT FROM AUTHOR]

The paper considers a method for determining the impedance of acoustic liner sample based on numerical simulation of physical processes in resonators at a grazing incidence of a sound wave. The test section of a grazing incidence impedance tube (GIIT) and a model of acoustic liner sample, consisting of 7 honeycomb cells with a depth of 27 mm and 11.9% porous perforate facesheet is simulated. Numerical simulation is based on direct solution of the non-stationary compressible Navier-Stokes equations in a three-dimensional formulation. The pressure-time signals recorded in numerical simulation are processed by the Dean method. The obtained impedance is compared with that educed on full-scale experiment data for a single-layer acoustic liner sample, consisting of 72 honeycomb cells of a similar design. The impedance eduction is performed by minimizing the residual functional, which is the total discrepancy between the calculated and experimental acoustic pressure on the wall of the GIIT. The calculated values of the acoustic pressure are determined by the numerical solution of the Helmholtz equation and the linearized Euler equations for a duct with an impedance wall. [ABSTRACT FROM AUTHOR]

The paper deals with a delayed version of prey predator model with the incorporation of modified Holling-Tanner functional response in predator population. The model highlights the loss in prey population via migration and the natural death rate due to age factor and other reasons such as prenatal death, infection etc. The model also considers the significance of delay in the predator population which is taken as a parameter of bifurcation. Local stability analysis is done in the paper and it is examined that delay is important in attaining system's stability. Hopf bifurcation is discussed in brief along with the stability of bifurcated type of periodic solutions stability by considering normal form and central manifold theories is applied. Numerical simulations asserts the theory and concludes the paper. [ABSTRACT FROM AUTHOR]

The paper is dedicated to identification and computational study of control laws for a spaceplane's ramjet aimed at providing a target value of thrust and impulse. An algorithm to identify the law of fuel mass flow rate control that provides a target value of thrust has been developed and implemented on software level. Resultant control laws have been verified by numerical simulation data. [ABSTRACT FROM AUTHOR]

The paper considers a relatively simple method for creating interactive electronic models of physical systems that does not require programming and automatic generation of numerical models of complex physical systems. The created training models are available for use via the Internet and allow almost unlimited on-line editing by users. The options of using the created electronic models to support mass individualized learning and the organization of independent educational and scientific research of students are discussed. The development is based on the original method of physical object-oriented modeling (POOM), which is an application of traditional ideas of object-oriented programming to the problems of constructing and configuring numerical models of relatively complex physical systems. Within its framework, a computer model of a physical system is constructed as a set of software objects that model the behavior of its components relative to separate physical elements: particles and fields. The interaction between the elements of the model is described using self-adapting algorithms, the choice of which is set during the construction of the model, depending on the physical approximation used: classical or relativistic. An electronic designer of interactive models of physical systems, represented in the form of arbitrary aggregates of classical and relativistic particles interacting with each other and external fields, has been created on the basis of the POOM ideology and Java-Script technology. The possibility of using an electronic designer as a basis for students to conduct independent research work on the study of the physical properties of complex mechanical systems, the analysis of which goes beyond the standard programs in physics and mathematics, is tested. The heuristic capabilities of the models created with the help of an electronic designer are demonstrated. The electonic designer is focused on the development of a series of virtual physical models to support classroom and online courses in physics and the organization of independent creative work of students in the MOOC–education system. [ABSTRACT FROM AUTHOR]

The paper analyzes the parametric uncertainty of the considered mathematical model, identifies the main parameters of the model, which undergo changes in the course of the real functioning of the studied pneumatic system. A nonlinear synergistic law for controlling the position of the piston of a pneumatic actuator has been developed, which has robust properties to changing the parameters of the model within the maximum permissible limits. The obtained results of computer modeling confirm the robust properties of the obtained nonlinear synergetic control laws and the achievement of the set technological control goal - moving the rod to a given position under conditions of parametric uncertainty. The robust properties of a closed-loop control system with integral adaptation are considered with an uncontrolled variation of the load mass within: m1 = 0,6 kg and m2 =0,9 kg and variations of the viscous friction coefficient in the following values:) Ƞ1 =101 N · s/m; and Ƞ1 =101 N · s/m. [ABSTRACT FROM AUTHOR]

The paper presents the results of numerical simulation of the process of suppressing resonant vibrations in a thin-walled structure interacting with a fluid. The damping mechanism is based on the use of piezoelectric elements as a sensor and actuator incorporated into an active system of vibration suppression. The parameters of the control action are selected based on the analysis of the solutions to a series of harmonic problems. A comparison of transient processes obtained with optimal and non-optimal coefficients is carried out. [ABSTRACT FROM AUTHOR]

In this paper, a path tracking controller based on distance-only measurements for nonholonomic mobile robots is presented. First, a kinematic model of the robot appropriate for path tracking applications is derived. Using a look-ahead approach, a time-varying feedback controller is proposed. The stabilities properties of the closed-loop system are analyzed in case of circular and straight-line path tracking using the theory of Lyapunov, and asymptotic stability is proved. In particular, for straight-line tracking, the steady-state error is shown to be equal to zero. Numerical simulations and experiments are carried in order to validate the proposed feedback path tracking control. [ABSTRACT FROM AUTHOR]

This paper is tackling the elbows bending process using hot mandrels. Through this process the pipe is pushed over a fix or mobile mandrel, which defines the expansion and the radius of curvature and is very important that mandrel deformation to be minimum. The paper presents the finite element model developed for the process described above, the optimization of tool parameters used to obtain and validate the simulation conditions in order to evaluate the effect of different materials on mandrels performances. The numerical simulation analyses were carried out by finite element analysis software NASTRAN and LS-DYNA which has a vast array of capabilities to simulate extreme deformation problems. Results obtained following the manufacturing process FEM simulation optimization are expected to reduce the mandrel production and exploitation costs. [ABSTRACT FROM AUTHOR]

There are a lot of researches on virtual instruments, but there are few on classical Chinese instruments, and the techniques used are very limited. This paper uses Unity 3D and Kinect camera combined with virtual reality technology and gesture recognition method to design a virtual playing system of Guzheng, a traditional Chinese musical instrument, with demonstration function. In this paper, the real scene obtained by Kinect camera is fused with virtual Guzheng in Unity 3D. The depth data obtained by Kinect and the Suzuki85 algorithm are used to recognize the relative position of the user's right hand and the virtual Guzheng, and the hand gesture of the user is recognized by Kinect. [ABSTRACT FROM AUTHOR]

The structure of a market is determined by the number of active firms in it. Over time, this number is affected by the exit of existing firms, called incumbents, and entries of new firms, called entrant. In this paper, we considered a market governed by the Cobb-Douglas utility function such that the demand function is isoelastic. Each firm is assumed to produce a single homogenous product under a constant unit cost. Furthermore, firms are assumed to be boundedly rational in adjusting their outputs at each period. A firm is considered to exit the market if its output is negative. In this paper, the market is assumed to have zero barrier-toentry. Therefore, the exiting firm can reenter the market if its output is positive again, and new firms can enter the market easily. Based on these assumptions and rules, a mathematical model was developed and numerical simulations were run using Matlab. By setting certain values for the parameters in the model, initial numerical simulations showed that in the long run, the number of firms that manages to survive the market varies between zero to 30. This initial result is consistent with the idea that a zero barrier-to-entry may produce a perfectly competitive market. [ABSTRACT FROM AUTHOR]

The paper mainly focuses on the route design for community patrol by aircraft. On the basis of the surrounding condition, the aircraft will first build a model of the surrounding environment, grid the model next, and rectangle irregular barriers in the model. Based on Boustrophedon, the paper has raised a new strategy for gridding the surrounding environment. Under the new strategy, the overall environment will be divided into few patches. By covering all the patches, we will secure a full view of the surrounding environment. With the contribution of MATLAB, the aircraft has achieved experimental simulation over the whole area, as such, the whole environment has ensured a full coverage. [ABSTRACT FROM AUTHOR]

Today, the inverse identification or optimization of material model parameters is very often used to find input parameter values for use in relevant nonlinear material models. These parameter values should enable the responses of structures obtained from numerical simulations to very closely approximate the real responses of such structures obtained from experiments. Due to the popularity of concrete as a construction material, much attention is paid to nonlinear material models that aim to describe its behavior. This paper is focused on the optimization-based inverse identification of the parameters of two related nonlinear concrete material models which are known as the Karagozian & Case Concrete model and the Karagozian & Case Concrete model - Release III. Within this paper, the identification of the material model parameters is performed on the basis of interaction between nonlinear numerical simulations, optimization algorithms and experimental data, the latter of which take the form of a loading curve measured during a triaxial compression test. A comparison of the responses of both of the used material models when the optimized parameters are employed is, of course, part of this paper. [ABSTRACT FROM AUTHOR]

The paper presents the numerical simulation of thermo-hydraulic behaviour of coolant in nuclear reactor VVER-440 under reactor pool filling conditions. Temperature distribution and mixing of coolant with different temperatures during filling process are discussed. [ABSTRACT FROM AUTHOR]

The paper presents a procedure for numerical simulation of the air permeability in the transversal direction of protective face masks. Two types of three-layer face masks were considered, and their air-permeability was experimentally measured together with the masks' structural, geometric and mass characteristics. Two simulation approaches were tested with the actual thickness of the mask (Model 1-1) and a scaled model, corresponding to 4 times augmentation of the mask's thickness (Model 1-4). A total of 12 steady-state simulations were conducted with a complete comparative analysis between the two models and the two masks (porous medium). An adapted ENGYS® version of the computational code OpenFoam® was applied. The numerical results were verified with the experiments and showed a very good correlation. [ABSTRACT FROM AUTHOR]

This paper presents numerical simulations using an open boundary algorithm with modified dynamic boundary condition (mDBC) for weakly compressible smoothed particle hydrodynamics models from particle-based code Dualsphysics. The problems of piping erosion in earth dams are aimed at studying the algorithm. The case 2D model of fluid flow past around a fixed cylinder is simulated, where various values of Reynold's numbers (Re 20 to Re 100) and different viscosity terms are considered. A constant velocity with different values of viscosity for generating various Reynold's numbers is modeled. The interaction between solid particles of the cylinder and fluid particles is concerned, the cylinder is affected by the hydrodynamics force caused by the flow of fluid particles. The solid particles of the cylinder are the observation points to obtain force and pressure due to the hydrodynamics forces. As a result of the simulation which is to show the capability to model 2D fluid flow with various Reynold's numbers. Drag coefficient, lift coefficient, and Strouhal number are compared to the previous work from literature. [ABSTRACT FROM AUTHOR]

NNW-UGKS, an engineering-oriented solver package based on the Unified Gas Kinetic Scheme(UGKS) for flows covering various regimes, is briefly introduced in the current paper. Then the hypersonic flowfield around a sharp-edged vehicle at high altitude is simulated with NNW-UGKS. The aerodynamic force coefficients, the pressure, the stress and heat distributions on the surface are compared with DSMC results. Good agreements have been achieved. [ABSTRACT FROM AUTHOR]

In this paper, a two-temperature nonlinear coupled constitutive Relations (NCCR) model is utilized to simulate the flows over a flat plate. The two-temperature NCCR model is implemented by involving the rotational relaxation term for the rotational energy equation. Thus, the rotational temperature and translation temperature in the flow field could be obtained simultaneously. The flow contours and temperature profiles over the flat plate are compared with those of multiple-temperature Navier-Stokes (NS) solver. The final results show that the two-temperature NCCR model would reproduce the solutions of NS solver at Ma=2. However, it behaves quite differently from the NS solver at Ma=5. It is also noted that the rotational temperature and translational temperature are close to each other at Ma=2. In contrast, the rotational temperature and translational temperature are totally different at Ma=5. [ABSTRACT FROM AUTHOR]

The development of blast-protective devices that direct blast and shock waves resulting in HE explosion to the safest side for humans and engineering constructions remains an urgent task in modern conditions. To optimize the design parameters of blast protection means, comprehensive research is required and the development of an optimal methodology that can help to improve the existing protective characteristics of those devices. The first stage in this direction is the study of an elevated (caused at some height above ground or floor) open explosion using experimental, analytical and numerical methods. In this paper, we obtained an assessment of the parameters characterizing the explosion of a 0.2 kg TNT charge. The features of shock wave propagation in an open explosion are determined using experimental, analytical and numerical methods. Authors revealed that it is necessary to use numerical methods with caution in modeling and decision-making. [ABSTRACT FROM AUTHOR]

This work is devoted to the improvement of methods of calculation and design of jib cranes with devices balancing their own weight of jib systems. The paper proposes a solution to the problem for optimizing the parameters of balancing devices. The solution to this problem presupposes an increase in the efficiency, reliability, and safety of operation both directly of such cranes and other types of hoisting-and-transport machines with jib systems, including in cold climates. The authors considered in detail the requirements for geometric parameters, following from recommendations for effective balancing of jib system own weight, as well as for ensuring strength of structures, such as counterweight moment relative to the point at the maximum boom reach; transition of counterweight rocker through the vertical at the minimum reach; principle of heights determining of the console bases from the beams strength condition; ratio of thrust placement on the boom; apex angle of the counterweight arms, etc. Also, when solving the task, a set of requirements is met, and some assumptions are made. In the course of the work, we assume that the jib device and the balancing system are considered as framed structure, elastic deformations of their elements are not taken into account; weight loads are considered as concentrated and are applied at the following points: the jib weight at a certain distance relative to the jib length from its pivot axis; weight of the guy rod in the middle of the guy rod; the overarm weight at a certain distance relative to the jib-arm pin hinge. All stages of the task were performed using computer modeling tools, which implies both a decrease in the labor intensity of calculations themselves, and creation simplification of the current slice of dynamic model using a recursive approach, modern methods of dynamic data analysis and reengineering techniques. [ABSTRACT FROM AUTHOR]

The automobile contains several very important parts, one of which is the friction clutch. Its importance comes from being it is a mechanical coupling device that plays the role of connecting and transmitting the torque generated in the engine to the gear set in the gearbox. The friction material is an important parameter due to withstand the mechanical and thermal load generated in the clutch system. This paper focused on studying the thermal behavior of four different friction lining materials (LUK, Tiger, G95, and HCC) to identify the temperature distribution for each material separately and then compare these materials to arrive at the best material that you can choose in the dry clutch design. Modeling of the model was done by the method of finite element and with the help of the ANSYS program to perform numerical simulations and show results. It may be determined that the thermoelastic behavior of the clutch is influenced by the type of frictional lining material used. After comparing the data, it was discovered that the materials (HCC and G95) were vulnerable to clutch activation for long periods. In the current investigation, the lining materials stood out because they demonstrated a high thermal efficiency when compared to the other materials in the prior study. [ABSTRACT FROM AUTHOR]