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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]

The paper deals with the description of GNSS-INS simulator used for testing algorithms of the airborne gravimetry. At first, some specifications of the simulator are presented. Then the basic principles, models, algorithms used in the GNSS-INS simulator are described. The next part of the article concerns the usage of the simulator for testing algorithms of the airborne vector gravimetry. Some simulation results conclude the paper. [ABSTRACT FROM AUTHOR]

The analysis of the interpolation error is particularly important for the error analysis of the finite element methods. In the previous paper, we proved that the finite element solution converges to an exact solution if the maximum circumradius of the triangular elements converges to zero. We call such situation "circumradius condition" and claimed that the circumradius condition is more essential than the well-known maximum angle condition. It is considered that the better finite element solution can be obtained by using the mesh division consists of "good" triangles. However, the generation of such mesh division is time consuming task within the simulation process of the finite element method. On the other hand, the effecient algorithm is known for computing Delaunay triangulation. However, the mesh division produced by Delaunay triangulation sometimes contains collapsed triangles. In this paper, we will introduce "circumradius condition" and show that the effecient error estimate can be obtained by the circumradius condition with Delaunay triangulation. [ABSTRACT FROM AUTHOR]

In this paper, we present the implementation of a lattice Boltzmann free surface algorithm for the simulation of water entry problems. The aim of this work is to isolate the effects of asymmetric impact on the water entry of a rigid wedge. Simulations for different heel angles were conducted in order to evaluate the influence of this parameter on the wedge dynamics, pile-up evolution, and velocity distribution. Our results indicate that the heel angle remarkably influences the physics of water impact. [ABSTRACT FROM AUTHOR]

The paper presents an algorithm for constructing of synthesizing control function. This algorithm is sufficiently convenient for numerical implementation and a wide class of nonlinear nonstationary systems of ordinary differential equations, provide the passage from initial state into to origin coordinates. We obtain a constructive condition for the choice of initial state for which the passage is possible with regard of the constraints imposed on the control. We consider an problem of control of single manipulator, for which we carry numerical simulation. [ABSTRACT FROM AUTHOR]

In order to describe the meso-damage of the refractories more accurately, and to study of the relationship between the mesostructured of the refractories and the macro-mechanics, this paper takes the magnesia-carbon refractories as the research object and uses the molecular dynamics method to instead the traditional sequential algorithm to establish the meso-particles filling model including small and large particles. Finally, the finite element software-ABAQUS is used to conducts numerical simulation on the meso-damage evolution process of refractory materials. From the results, the process of initiation and propagation of microscopic interface cracks can be observed intuitively, and the macroscopic stress-strain curve of the refractory material is obtained. The results show that the combination of molecular dynamics modeling and the use of Python in the interface to insert the cohesive element numerical simulation, obtaining of more accurate interface parameters through parameter inversion, can be more accurate to observe the interface of the meso-damage evolution process and effective to consider the effect of the mesostructured of the refractory material on its macroscopic mechanical properties. [ABSTRACT FROM AUTHOR]

The thermal process modeling based on the operating data is effective to overcome the deficiency of mechanism modeling. In order to reduce the computational complexity of data-driven modeling, many sample selection algorithms have been used to decreasing the training dataset scale. However, traditional sampling selection algorithm may fail to cover full-scale working condition of thermal process when the dataset has large density deviations, and the sample selection criteria is often irrelevant to the modeling prediction. To overcome these issues, this paper proposes a wrapper full-scale sample selection algorithm for thermal process modeling, in which, samples will be sequentially added until there is no improvement in prediction, and sample selection criteria is the prediction evaluated by KNN regression model beforehand. It reveals that our algorithm not only cover full-scale working condition of thermal process, but also has certain superiority in model accuracy. Numerical simulation and real thermal application are conducted to validate the performance of the proposed algorithm. [ABSTRACT FROM AUTHOR]

This paper presents the simulation of three-phase induction motor drives using Indirect Field Oriented Control (IFOC) in PSIM environment. The asynchronous machine is well known about natural limitations fact of highly nonlinearity and complexity of motor model. In order to resolve these problems, the IFOC is applied to control the instantaneous electrical quantities such as torque and flux component. As FOC is controlling the stator current that represented by a vector, the torque component is aligned with d coordinate while the flux component is aligned with q coordinate. There are five levels of the incremental system are gradually built up to verify and testing the software module in the system. Indeed, all of system build levels are verified and successfully tested in PSIM environment. Moreover, the corresponding system of five build levels are simulated in PSIM environment which is user-friendly for simulation studies in order to explore the performance of speed responses based on IFOC algorithm for three-phase induction motor drives. [ABSTRACT FROM AUTHOR]

The paper presents an algorithm for constructing of synthesizing control function. This algorithm is sufficiently convenient for numerical implementation and a wide class of nonlinear stationary systems of ordinary differential equations, provide the passage from initial state into to origin coordinates. We obtain a constructive condition for the choice of initial state for which the passage is possible with regard of the constraints imposed on the control. We consider an interorbital flight problem, for which we carry numerical simulation. [ABSTRACT FROM AUTHOR]

Localization of mobile station (MS) has now gained considerable attention due to its wide applications in military, environmental, health and commercial systems. Phrase angle and encode data of MSK system model are two critical parameters in time-of-arrival (TOA) localization technique; nevertheless, precise value of phrase angle and encode data are not easy to achieved in general. In order to meet the actual situation, we should consider the condition that phase angle and encode data is unknown. In this paper, a novel TOA localization method, which combine MUSIC algorithm and cross correlation algorithm in an appropriate interval, is proposed. Simulations show that the proposed method has better performance than music algorithm and cross correlation algorithm of the whole interval. [ABSTRACT FROM AUTHOR]

Five-Port Reflectometer is a microwave passivedevice where it implements the six-port algorithm to measure the complex reflection coefficient of material under test (MUT) through reflection on interface between MUT and microwave sensor. Initially, the Six-Port Reflectometer (SPR) was introduced by Engen in 1977 and major component used insix-port technique was designed in many types. When Riblet and Hanssonproposed ring junction with 5 ports only on 1981.Six ports ring junction has been reduced to five ports. In this paper, a dual frequency five ports ring junction circuit was designed, simulated and fabricated for reflection based sensing system. The fabricated five port ring junction is operating at frequencies of 0.64 GHz and 2.42 GHz. The measured result had good agreement with the simulated results for dual frequencies in terms of magnitude and phase. [ABSTRACT FROM AUTHOR]

In this paper, we present a comparative study involving several penalty functions that can be used in a penalty approach for globally solving bound mixed-integer nonlinear programming (bMIMLP) problems. The penalty approach relies on a continuous reformulation of the bMINLP problem by adding a particular penalty term to the objective function. A penalty function based on the 'erf' function is proposed. The continuous nonlinear optimization problems are sequentially solved by the population-based firefly algorithm. Preliminary numerical experiments are carried out in order to analyze the quality of the produced solutions, when compared with other penalty functions available in the literature. [ABSTRACT FROM AUTHOR]

Computer simulation of multiscale burning and detonation processes requires an exaflop-scale performance supercomputer. The paper present research from SRISA intended to development high-performance architectures of DSP extensions for burning process simulations. Also a number of solutions for dataflow coprocessor development based on self-timed circuits are proposed. [ABSTRACT FROM AUTHOR]

We have applied the finite difference time domain (FDTD) method with the supersymmetric quantum mechanics (SUSY-QM) procedure to determine excited energies of one dimensional quantum systems. The theoretical basis of FDTD, SUSY-QM, a numerical algorithm and an illustrative example for a particle in a one dimensional square-well potential were given in this paper. It was shown that the numerical results were in excellent agreement with theoretical results. Numerical errors produced by the SUSY-QM procedure was due to errors in estimations of superpotentials and supersymmetric partner potentials. [ABSTRACT FROM AUTHOR]

Monte Carlo (MC) is one of the powerful techniques for simulation in x-ray imaging. MC method can simulate the radiation transport within matter with high accuracy and provides a natural way to simulate radiation transport in complex systems. One of the codes based on MC algorithm that are widely used for radiographic images simulation is MC-GPU, a codes developed by Andrea Basal. This study was aimed to investigate the time computation of x-ray imaging simulation in GPU (Graphics Processing Unit) compared to a standard CPU (Central Processing Unit). Furthermore, the effect of physical parameters to the quality of radiographic images and the comparison of image quality resulted from simulation in the GPU and CPU are evaluated in this paper. The simulations were run in CPU which was simulated in serial condition, and in two GPU with 384 cores and 2304 cores. In simulation using GPU, each cores calculates one photon, so, a large number of photon were calculated simultaneously. Results show that the time simulations on GPU were significantly accelerated compared to CPU. The simulations on the 2304 core of GPU were performed about 64 -114 times faster than on CPU, while the simulation on the 384 core of GPU were performed about 20 - 31 times faster than in a single core of CPU. Another result shows that optimum quality of images from the simulation was gained at the history start from 108 and the energy from 60 Kev to 90 Kev. Analyzed by statistical approach, the quality of GPU and CPU images are relatively the same. [ABSTRACT FROM AUTHOR]

In this work, a nonlinear model based approach is presented for the altitude stabilization of a hexarotor unmanned aerial vehicle (UAV). The mathematical model and control of the hexacopter airframe is presented. To stabilize the system along the vertical direction, a Proportional Derivative (PD) control is taken into account. A particle swarm optimization (PSO) approach is used in this paper to select the optimal parameters of the control algorithm taking into account different objective functions. Simulation sets are performed to carry out the results for the non-linear system to show how the PSO tuned PD controller leads to zero the error of the position along Z earth direction. [ABSTRACT FROM AUTHOR]

Simulation algorithms for the sizing of stand-alone hybrid PV/Wind systems are a powerful tool in evaluating the optimum configuration that would cover the energy demand with a predefined reliability level at the lowest cost. Several parameters such as the interval of the simulation (day, day-night, hourly) and the consumption profile may significantly affect the optimum configuration. This paper examines the effect of these parameters within an optimum sizing simulation algorithm developed. The effect of these parameters was particularly evident at low battery capacities, which involve optimum configurations resulting in minimum cost. Furthermore, shift-able loads in the hourly-based weekly profile assumed in this study were identified, and a dynamic load management functionality was developed. In this approach, loads that could be shifted through time were dynamically allocated during periods of excess energy production by the hybrid PV/Wind system. The results showed an increase in system reliability from 95% to 97% when load shifting was introduced. Finally, sizing the system for only the static (non-shift-able loads) proved to withstand the addition of the extra shift-able loads while retaining the 95% reliability level when the load management functionality was introduced. Thus, a smaller installation with lower cost is achieved. [ABSTRACT FROM AUTHOR]

Parallel computational fluid dynamics simulations produce vast amount of numerical result data. This paper introduces a method for reducing the size of the data by replaying the interprocessor traffic. The results are recovered only in certain regions of interest configured by the user. A known test case is used for several mesh partitioning scenarios using the OpenFOAM toolkit®[1]. The space savings obtained with classic algorithms remain constant for more than 60 Gb of floating point data. Our method is most efficient on large simulation meshes and is much better suited for compressing large scale simulation results than the regular algorithms. [ABSTRACT FROM AUTHOR]

Parallel computational fluid dynamics simulations produce vast amount of numerical result data. This paper introduces a method for reducing the size of the data by replaying the interprocessor traffic. The results are recovered only in certain regions of interest configured by the user. A known test case is used for several mesh partitioning scenarios using the OpenFOAM toolkit®[1]. The space savings obtained with classic algorithms remain constant for more than 60 Gb of floating point data. Our method is most efficient on large simulation meshes and is much better suited for compressing large scale simulation results than the regular algorithms. [ABSTRACT FROM AUTHOR]

Building on the notion of systematically analyzing investment portfolio as a feedback system, there is a need of experimentation system. In this paper such system for experimenting with various traditional, classical, advanced, etc. models for portfolio management is described. The main objective is to have the ability to compete the models systematically on a unified data track. [ABSTRACT FROM AUTHOR]

In forging industry, net shape or near net shape forging of gears has been the subject of considerable research effort in the last few decades. So in this paper, a multi-objective optimization methodology of net shape gear forging process design has been discussed. The study is mainly done in four parts: building parametric CAD geometry model, simulating the forging process, fitting surrogate meta-models and optimizing the process by using an advanced algorithm. In order to maximally appropriate meta-models of the real response, an adaptive meta-model based design strategy has been applied. This is a continuous process: first, bui Id a preliminary version of the meta-models after the initial simulated calculations; second, improve the accuracy and update the meta-models by adding some new representative samplings. By using this iterative strategy, the number of the initial sample points for real numerical simulations is greatly decreased and the time for the forged gear design is significantly shortened. Finally, an optimal design for an industrial application of a 27-teeth gear forging process was introduced, which includes three optimization variables and two objective functions. A 3D FE nu merical simulation model is used to realize the process and an advanced thermo-elasto-visco-plastic constitutive equation is considered to represent the material behavior. The meta-model applied for this example is kriging and the optimization algorithm is NSGA-II. At last, a relatively better Pareto optimal front (POF) is gotten with gradually improving the obtained surrogate meta-models. [ABSTRACT FROM AUTHOR]

Drop test simulation via finite element methods can help simulate the effects of high impact and shock. It has become an indispensable tool during the virtual product design processes to reduce the cost of experimental test and to help improve the durability of products. The choice of a reliable contact method is critical for drop test simulation. Of all the contact algorithms, the penalty method has the advantage of taking the contact constraint into account without increasing the degrees of freedom while being easy to implement into existing software. The implicit analysis is generally known to be more accurate than the explicit analysis, but has convergence issues. This paper presents a penalty finite element method based on dynamic implicit scheme to implement impact planes for drop test simulation. An idea of impact element groups, which allows multiple impact planes with different normal directions, is presented. Two impact plane types are implemented: 'Full general' and 'Slide/no bounce'. The general drop process is divided into three durations with different time step sizes to efficiently and accurately capture the fast change within the microtime of the impact. Typical and interesting drop test models are simulated and discussed for the presented method. [ABSTRACT FROM AUTHOR]

Numerical models serve an important role in eddy current non-destructive evaluation applications. The results of computational models provide meaningful insight into the underlying physics, help theoretically visualize the field/sample interaction and help optimize sensor design and assist algorithms developing for interpreting the measured signals. However, three dimensional computational models can be time consuming. This paper presents a fast and efficient GPU based numerical model for simulating eddy current testing techniques. The model, based on boundary integral method, uses novel matrix compression techniques to optimize the solver performance on GPU architectures. Validation results of model predictions for a number of sample geometries are presented. [ABSTRACT FROM AUTHOR]

In this paper we discuss the second version of Flecs, a generic, open-source coupling shell that can be used to join two or more arbitrary solvers. In general multidisciplinary computations are very computing-intensive. A remedy against long computing times is large-scale parallelism. The challenge of the present parallelization work is to obtain acceptable computing times and to get rid of severe memory requirements that exist on sequential machines, for the generic flow problems at hand. The aim is to provide a flexible platform for developing new data transfer algorithms and coupling schemes. [ABSTRACT FROM AUTHOR]

This paper deals with the decentralized approach of target geolocation and sensor bias estimation for multiple unmanned aerial vehicles with bearing angle sensors. The bias of bearing sensor is crucial source that impoverish accuracy of target geolocation. The decentralized estimation approach utilizes the information filtering and dual estimation. The local estimator running in each vehicle estimates the target motion and its sensor bias simultaneously in dual estimation framework. The dual estimation consists of two parallel filters, which are the state filter for target motion and the parameter filter for sensor bias. The information increments of target motion in local vehicles are shared with other vehicles in information filtering framework which is suitable for multiple sensor estimation than conventional Kalman filter. Performance comparison of the proposed decentralized geolocation algorithm with bias estimation with the centralized approaches is demonstrated by numerical simulation. [ABSTRACT FROM AUTHOR]

This paper demonstrates the use of an intelligent shimming system to compensate for changes in process output due to tool wear. A new tool concept with integrated hydraulic cavities used as actuators in feedback control system is presented. By prescribing a hydraulic pressure in the individual cavities the blank-holder force distribution can be controlled during the punch stroke. By means of a sequence of numerical simulations abrasive wear is imposed to the deep drawing of a rectangular cup. The abrasive wear is modelled by changing the tool surface geometry using an algorithm based on the sliding energy density. As the tool surfaces are changed the material draw-in is significantly altered when using conventional open-loop control of the blank-holder force. A feed-back controller is presented which is capable of reducing the draw-in difference to a certain degree. Further a learning algorithm is introduced to the system, which is able to improve the response of the feed-back system significantly. [ABSTRACT FROM AUTHOR]

The paper focuses on the miniaturization of the bulging test for material characterization of micro tubes. For the design of the experimental device, numerical simulations are conducted first. Even if no scale effect is taken into account in material modeling, numerical results give some information before designing the set-up and performing experimental works: level of pressure inside the tube, volume of fluid necessary to create such a level of pressure and bulge height to measure. The main results are a design of the experimental device and choices for its instrumentation. [ABSTRACT FROM AUTHOR]

In this paper, we focus on the simulation of linear elastic behaviour of plates using a 3D approach which numerical cost only scales like a 2D one. In the case of plates, the kinematic hypothesis introduced in plate theories to go from 3D to 2D is usually unsatisfactory where one cannot rely on St Venant's principle (usually close to the plate edges). We propose to apply the PGD (Proper Generalized Decomposition) method [1] to the simulation of the linear elastic behavior of plates. This method allows us to separately search for the in-plane and the out-of plane contributions to the 3D solution, yielding significant savings in computational cost. The method is validated on a simple case and its full potential is then presented for the simulation of the behavior of laminated composite plates. [ABSTRACT FROM AUTHOR]

This paper presents the formulation of an axi-symmetric element based on an efficient method called 'Inverse Approach' (I.A.) for the numerical modeling of cold forging process. In contrast to the classical incremental methods, the Inverse Approach exploits the known shape of the final part and executes the calculation from the final part to the initial billet. The assumptions of the proportional loading and the simplified tool actions make the I.A. calculation very fast. The metal's incompressibility is ensured by the penalty method. The comparison with ABAQUS® and FORGE® shows the efficiency and limitations of the I.A. This simplified method will be a good tool for the preliminary preform design. [ABSTRACT FROM AUTHOR]

In this paper we illustrate the features and study the applicability of transactional memory ™ as an efficient and easy-to-use alternative for handling memory conflicts in multi-theaded physics simulations that use shared memory. The tool used for our preliminary analysis of this novel construct is IBM’s freely available Software Transactional Memory (STM) system. Instead of attempting to apply it to a production grade simulation code, we developed a much simpler test code that exhibits most of the salient features of modern unstructured mesh algorithms, but without the complicated physical models. We apply STM to two frequently used algorithms in realistic multi-physics codes. Our computational experiments indicate a good fit between these application scenarios and the TM features. [ABSTRACT FROM AUTHOR]

In this paper an approach for modeling and control of robots with elasticities in power trains and in structural parts is presented and experimentally verified. For this purpose object-oriented, nonlinear models are developed in the modeling language Modelica. A system theoretical study of the generated models shows that a direct inversion of the models, due to the unstable zero dynamics, is not possible. Therefore an algorithm for the approximate inversion is developed. With this inversion method an approximate inverse model considering structural elasticity for a 6-axis robot is created and verified for the control of the robot. The new control leads to a considerable improvement of the driving characteristics of the robot in the experiment. [ABSTRACT FROM AUTHOR]

The aim of this paper is to simulate the interaction between a two-dimensional incompressible viscous flow and a rigid airfoil with two degrees of freedom. The airfoil can rotate around its elastic axis while oscillating in the vertical direction. The numerical simulation consists of a coupled system of below mentioned equations: 1- Governing equations of flow field which are solved by SIMPLE algorithm. 2- A system of nonlinear ordinary differential equations which describes the airfoil motions. To determine the location of airfoil in each time step an algorithm based on VOF method for a system of fixed mesh is developed. Results are compared well with references. [ABSTRACT FROM AUTHOR]

Due to the increasing computing power of the graphics processing units (GPU), they are becoming more and more popular when solving general purpose algorithms. As the simulation of quantum computers results on a problem with exponential complexity, it is advisable to perform a parallel computation, such as the one provided by the SIMD multiprocessors present in recent GPUs. In this paper, we focus on an important quantum algorithm, the quantum Fourier transform (QTF), in order to evaluate different parallelization strategies on a novel GPU architecture. Our implementation makes use of the new CUDA software/hardware architecture developed recently by NVIDIA. [ABSTRACT FROM AUTHOR]

The subject of the paper is a problem of designing control algorithms for mechanical systems with uncertainty. We consider a generic Lagrangian mechanical system under the assumption that its mass-inertia parameters are not known exactly and that the system is subjected to unknown bounded disturbances. We assume also that the disturbances are smaller than the control forces which in turn do not exceed the force of gravity. A bounded control is proposed which, under certain conditions, steers the system from an arbitrary initial state to a prescribed terminal state in finite time. To this end, first, for some reference dynamical system close to the original one we design a trajectory connecting the initial and the terminal states. Then, using the trajectory tracking technique we steer the system under consideration to the prescribed terminal state. The proposed approach is illustrated by the results of the computer simulation of steering a plain two-link pendulum. [ABSTRACT FROM AUTHOR]

This paper presents an integrated true three-dimensional simulation of resin flow and wire sweep in microchip encapsulation. A FVM-based decoupled solution algorithm with the hybrid elements capability is adopted to calculate the resin flow during mold filling. Furthermore, a highly flexible mesh generation technique especially tailored for the IC packages is also proposed to mesh the model with high quality element both in the flow and gapwize directions. Thanks to the efficiency of the proposed methodology in terms of CPU time and memory requirement, the industrial packages with complex geometry and high pin count can be analyzed with minimum model simplification. Finally, a user-friendly integrated environment is also developed to link the flow analysis with structure analysis to provide the total solution for wire sweep assessment. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

The simulation of high-velocity impact and penetration is inhibited by complex material behavior and large deformations. Lagrangian formulations best model complex materials because history-dependent variables and material boundaries are not advected. However, Lagrangian finite elements are limited by large deformations. Recently, meshfree particle methods have been used to avoid such limitations, and have demonstrated greater accuracy than traditional erosion methods (wherein deformed elements are removed). Though the variable connectivity of particles enables them to model large deformations, it requires more computational effort than (fixed-connectivity) elements. Therefore, an algorithm was designed to convert deformed elements to particles, thus providing the ability to model large deformations where needed, while maintaining the efficiency of elements elsewhere. This combination is essential in three dimensions, where problem size demands efficiency. In this paper, the conversion algorithm is demonstrated for several three-dimensional simulations of high-velocity impact and penetration. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]